Title of Invention	A CORIOLIS FLOWMETER HAVING A FLOW TUBE AND A BALANCE BAR AND A METHOD OF FORMING THE SAME
Abstract	The invention relates to coriolis flowmeter having a flow tube and a balance bar that are adapted, when in use, to be vibrated in phase opposition in a driven plane to generate a corio lis response in said vibrating flow tube representing infomlation pertaining to material flowing through said vibrating flow tube, said flow tube comprises a center portion and an extension at each end; said corio lis flowmeter comprising: a case surrounding said flow tube center portion and said balance bar with said balance bar being substantially parallel to and surrounding said flow tube center portion; a first and a second axial end of said case; an opening in each of said case ends for receiving said flow tube extension that project beyond said case ends; said opening in said case ends is coaxial with a longitudinal axis of said flow tube extension; brace bar means coupling ends of said balance bar to said flow tube; case connect link means having a first end coupled to said balance bar and having a second end coupled to an inner wall of said case; said case connect link means is effective to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to said longitudinal axis of said flow tube in said driven plane; a cylindrical cone connect means having an outer circumference coupled to said case ends and having a circular opening coaxial with said flow tube extension for sealably receiving said flow tube extension; said cylindrical cone connect means being axially positioned between a tenninus of said flow tube extension and said case connect link means.

Title of Invention

A CORIOLIS FLOWMETER HAVING A FLOW TUBE AND A BALANCE BAR AND A METHOD OF FORMING THE SAME

Abstract

The invention relates to coriolis flowmeter having a flow tube and a balance bar that are adapted, when in use, to be vibrated in phase opposition in a driven plane to generate a corio lis response in said vibrating flow tube representing infomlation pertaining to material flowing through said vibrating flow tube, said flow tube comprises a center portion and an extension at each end; said corio lis flowmeter comprising: a case surrounding said flow tube center portion and said balance bar with said balance bar being substantially parallel to and surrounding said flow tube center portion; a first and a second axial end of said case; an opening in each of said case ends for receiving said flow tube extension that project beyond said case ends; said opening in said case ends is coaxial with a longitudinal axis of said flow tube extension; brace bar means coupling ends of said balance bar to said flow tube; case connect link means having a first end coupled to said balance bar and having a second end coupled to an inner wall of said case; said case connect link means is effective to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to said longitudinal axis of said flow tube in said driven plane; a cylindrical cone connect means having an outer circumference coupled to said case ends and having a circular opening coaxial with said flow tube extension for sealably receiving said flow tube extension; said cylindrical cone connect means being axially positioned between a tenninus of said flow tube extension and said case connect link means.

Full Text	FIELD OF THE INVENTION This invention relates to a coriolis flowmeter and in particular to a single tube corollas tlowmeter structure for connecting the vibrating elements of the carioles flow meter to the tlowmeter case. The invention further relates to a coriolis flowmeter that can be manufactured, tested, balanced, and stored prior to the attachment of process connection llanges. PROBLEM It is a problem to provide a single How tube coriolis tlowmeter that operates satisfactorily over a wide range of variations in the operating parameters of the tlowmeter. These parameters include operating temperature, the density of the material tlow as well as the material pressure and How rate. A change in material density, thermally induced stress in the tlow tube, or pressure stress on the tlow tube can each result in an unbalanced condition which effects the accuracy of the tlowmeter. Changes in these parameters degrade the static and dynamic isolation of the vibratory elements of the tlowmeter. The problem is to keep the vibratory elements immune from the effects of changes in operating parameters. The accelerations that result from the change in operating parameters impair tlowmeter accuracy lay adding to or subtracting from the coriolis acceleration of the material, fee unwanted accelerations cannot be compensated torn because they vary with the mounting conditions of the tlowmeter. In addition, the mounting conditions often change with time and temperature in unknown ways. twin though a variation of the material parameters and mounting conditions is to be expected, it is desired that the tlowmeter remain operational and produce accurate output inebriation. It is also desired that the structural integrity of the tlowmeter elements be maintained as these parameters vary. It is a goal to design a coriolis tlowmeter so that it operates with suitable accuracy and does not destroy itself as the flowmeter elements are subject to varying operating temperatures, flowmeter designers also desire that the flowmeter calibration will remain constant and flat over a reasonably wide range material densities. In order to achieve these design objectives, a Coriolis flowmeter must have a dynamically balanced vibrating structure that operates in a controlled and predictable manner over a range oi^ operating parameter variations. The flowmeter elements external to the vibrating system should not vibrate or communicate vibration to the vibrator}^ system. A coriolis flowmeter often comprises a single straight flow tube surrounded by a balance bar and brace bars coupling the balance bar ends to the flow tube. In operation, vibration nodes (regions of no vibration) occur between the flow tube and the balance bar. Ice nodes define the length of the flow tube that is subject to Coriolis force. The vibration nodes of the flow tube and the surrounding balance bar should remain in the brace bars over the range of parameters for which the flowmeter is designed. Since the balance ban brace bar. and flow tube comprise a dynamically balanced system, the vibrating mass times the vibration velocity oi^ the balance bar should equal the vibrating mass limes the vibration velocity ol' the flow tube. As long as these conditions are met, and no other unbalanced forces or torques are applied to the non-vibratory elements of the flowmeter, the vibration nodes remain in the brace bars and the other flow meter elements remain free from vibration. However, prior art attempts have all fallen short of meeting these conditions. It is a problem of prior art to provide a coriolis tlowmeler structure for which a shift of the material density does not degrade the static and dynamic isolation of the flow meter’s vibratoi7 system and the corresponding reduction in the accuracy of the meter. It is also a problem in the manutacture. balancing and testing of a coriolis flowmeter to minimize the number of coriolis flowmeter of a given model that must be maintained in inventory. The reason for this is that there are more than twenty deliberant types of end flanges that may be coupled to each of flowmeter. There are perhaps eight different sizes of flowmeter resulting in 120 different meters that need to be stocked in order to have rapid response to sales orders. At a cost of several thousand dollars each, the amount money tied up in inventory can be significant. It is desired that flow meters be of such a design that they can be balanced, and tested before the flanges are attached. This would enable the stocking of far fewer finished meters without flanges. The desired flanges would be welded on with the receipt of each order. SOLUTION fee above problems are solved and an advance in the art is achieved b\ the present invention. In accordance with the present invention, three separate connection points are provided at each end of the flowmeter between the vibrating structure and the flowmeter case including the end llanges. A Loris such connection point is in the end flange where the flow tube end is joined to the end flange. A second connection point is provided by case connect links which couple the balance bar ends to the inner wall of the case. Ice third connecting point in each end of the flowmeter is provided by a circular element termed a cone connect, 1 his third connection point is provided by bonding (usually brazing) the flow tube to the cone connect element at the flow tube location where it extends through an opening in the case end and projects axially outward towards the flow tube end. Ibis cone connect connection is. like the other two connections, of limited length in the direction of the tube axis. There is a length of unsupported flow tube between the flange connection and the cone connect and another length of unsupported How tube between the cone connect and the case connect links. Since these unsupported portions loathe How tube are not coupled to any other structure, a void surrounds these portions of the How tube. The outermost void (in the neck of the flange) allows the welding of a (langc to the case end at this location without overheating or stressing the How tube. Also, the amount of heat required to effect a weld at these two locations is tar less than would be required if the entirety of this portion of the tlow tube was thermally coupled to the entire structure between the end llange and the case end. The provision of three points of coupling at each end of the tlow tube to the supporting structure of the flowmeter minimizes the communication of vibrations to the vibratory structure the flowmeter that are generated by extreme conditions of parameters such as material density. It does this by the use of the case connect links to enable vibration amplitude ratio balancing and it uses the cone connect element to keep unbalanced torque away from the vibrato it structure of the flowmeter. The reduced communication of vibrations to the vibratory structure of the flowmeter increases the accuracy and reduces the effect that different mounting conditions have on the flowmeter. In accordance with another embodiment of the present invention the coriolis flowmeter is manufactured, tested, and balanced prior to the time that the end flange is actually attached. At this stage of completion, the internal elements of the tlowmeter are fully operational and are sealed or isolated by the cone connect element. The end portions of the flow tube extend axially outward from each of the case ends and their cone connect elements. Because the case is sealed and the flow tubes are rigidly affixed to the case ends, the tube ends may be temporarily coupled to a source of material tlow at this time. The flowmeter may then be balanced. I he tlowmeter may be indefinitely stored in this state until an order is received from a customer. Then, the needs of the customer and the details of the end flanges required by the customer are made known and the appropriate end llanges may be coupled to the How tube projections and the case ends by suitable welding operations. The balancing and testing and subsequent temporary storage of the flowmeter prior to it being connected to end flanges is advantageous in that it minimizes the inventory that otherwise would have to be maintained by a supplier. If finished flowmeters were required to be stored with over twenty known types of llanges, the inventory would have to be enormous. An alternative embodiment of the invention provides a case connect link that is not directly connected at its ends between the balance bar and the inner wall of the case. Instead, the case connect link has a bend in its central portion and has its outer end connected to a flat surface of the cone connect element. In this second embodiment, the cone connect link is circular as in the first embodiment but has a larger diameter with the outer circumference of this circular cone connect element engaging the inner circular surface of the flowmeter case end. By this means, the case connect link has sufficient rigidity to prevent relative motion between the balance bar ends and the inner wall of the case. At that the same time, due to the bend in the case connect link, the case connect link is able to telex and accommodate changes in the diameter of the balance bar due to thermal changes. Ice circular cone connect element functions as before described in that it has an opening in its center portion through which the flow tube extends. It differs in that the large outer diameter of the cone connect allows relative axial movement between its outer and inner connection points. This compliance can lower the thermal stress in the flow tube. The cone connect element of this embodiment, like the previous embodiment, also has sufficient rigidity in the radial direction to terminate the dynamic portion of the (low tube and allow balancing prior to flange welding. It also seals the case interior from the environment. It can therefore be seen that the present invention is advantageous in phi it provides a flowmeter structure that maintains the dynamic isolation vibratory system of the flowmeter. It further permits the flowmeter to be tested. balanced, and stored in a state in which it is devoid of a flange: the clang chive installed only when the specific model flange required by the customer is known. An aspect of the invention comprises a coriolis (flowmeter a How tube and a balance bar that are adapted, when in use, to be vibrated in polkas opposition in a driven plane to generate a coriolis response in said \brainy flow tube representing information pertaining to material (lowing through said vibrating flow tube, said flow tube comprises a center portion and an extension at each end; said coriolis flowmeter comprising: a case surrounding said tlow tube center portion and said balance bar being substantially parallel to and surrounding said flow tube center portion; a first and a second end of said ease: an opening in each of said case ends for receiving end portions of said How tube that project beyond said case ends: said opening in said ease ends is with a longitudinal axis of said How tube extension: brace bar means coupling ends of said balance bar to said How tulle; case connect link means hexing a first end coupled to said brace bar as well as to said balance bar and a second end coupled to an inner wall of said case: said case connect link means is effective to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to said longitudinal axis of said flow tube in said driven plane; a cylindrical cone connect means having an outer cireumleienee coupled to said case end and having a circular opening coaxial with said How tube for seal ably receiving said flow lube; and said cone connect means being axially positioned between a terminus of said flow tube and said case ennui link means. Preferably said How tube extends the length of said case and has said flow tube extensions that project through said circular opening in said cone connect means and beyond said case ends to said terminus of said How lube extension. Preferably said terminus of each said How lube extension is devoid o\^ attachment to any structure axially outward of said case ends Preferably the coriolis flowmeter includes an end flange coupled to said terminus of each said flow tube extension for enabling said coriolis llowmelcr to be coupled to a material source ; a circular opening on an axial end surface of said end flange, and a wall on an inner surface of said circular opening Hal seal ably engages said flow tube extension. Preferably the coriolis flowmeter comprises: a cylindrical neck of said case end extending axially outward from said case end: said neck has a center opening coaxial with said How tube and a cylindrical inner surface Thai surrounds a portion of said flow tulle that projects beyond said case end: said cylindrical inner surface of said neck has a greater diameter than the diameter of said flow tube; and a circular cavity in said neck defined b\ the space between said How tube and said cylindrical inner surface of said neck. Preferably the coriolis flowmeter further includes a curved portion in a planar surface of said case connect link means. Preferably said cone connect means has a flat surface having an plane bend to permit a change in the effective diameter of said circular cone connect means in response to changes in the diameter of the portion case end to which said cone connect means is coupled. Preferably said second end of said case connect link means comprises a connection of said second end of case connect link means to said inner wall of said case, Prelerably said intermediate connection means includes a surface of said cone connect means whose perimeter is connected to a surface of said inner wall of said case. Preferably the coriolis flowmeter includes: a driver D that vibrates said flow tube center portion and said balance bar in a drive plane in phase opposition to each other, said vibrations in said drive plane and said material flow are jointly elective for inducing coriolis detlections in said tlow tube; pick off means coupled to said How tube that deflect said coriolis detlections: said pick off means generate signals representing information pertaining to said material flow in response to said detection of said coriolis detlections: and meter electronics that receive said signals from said pick off means and generates output information pertaining to said material flow. Preferably said tlow tube and said flow tube extension at a constant diameter torn the length of said case and has said ends portions that project through said opening in said cone connect means at said constant diameter to said terminus of said How tube extension. Preferably said terminus of each said end portion of said How tube is devoid of attachment to any structure axially outward from said case ends. Preferably the coriolis llowmeter further includes an end (Lange coupled to said How lube extension for enabling said coriolis llowmeter to be coupled to a material source; a circular opening on an axial end of said clang. and a wall on an inner surface of said circular opening that seal ably engage said How lube extension. Preferably the coriolis tlowmeter further includes a sealed cavity defined by space between the outer surface of said end portion of said How tube and said inner cylindrical surface of said neck of said case end and a cylindrical inner surface of a portion of said end (lange; said sealed cavity having an axiaily outer end comprising an outwardly projecting element of said Hanger seal ably engaged with said tlow tube extension: said sealed cavity having an axially inner end comprising said cone connect means. the coriolis (lowmeter further includes and end llange; a neck of said end flange having a first end integral with said end flange and having second end connected to an axiaily outer end of said neck of said case end; a cylindrical opening in said end llangc and in said neck of said end llange for receiving said terminus of said flow tube extension: said cylindrical opening in said neck of said end flange and in a portion of said end flange has a diameter that is substantially greater than the exterior surface of said How lube extension to define a void between said exterior surface of said flow tube extension and said cylindrical inner surface of said neck of said end llange and a cylindrical inner surface of said portion of said end llange; and an axiaily outwardly projecting element in an axiaily outer surface of said end flange having a cylindrical opening whose walls have an inner diameter that seal ably receive the terminus portion of said flow tube extension. Preferably said case includes walls parallel to the longitudinal axis of said flow tube; said case further includes said case ends affixed to ends of said walls and oriented substantially perpendicular to said cylindrical walls; the exterior surfaces of said case ends includes a neck coaxial with said opening in said case ends, said opening in said case ends receives said cone connect means and as well as a said portion of said flow tube extension which project axiaily outwards beyond said case ends, said neck has a cylindrical inner surface of a greater diameter than the exterior surface of said flow tufted extension to define a void comprising the space between said exterior surface old said flow tube and said inner surface of said neck. Preferably the coriolis flowmeter further includes: an end flange coupled to said terminus of said flow tube extension for enabling said coriolis flowmeter to be coupled to a pipeline: Preferably said case comprises: cylindrical walls oriented parallel to the longitudinal axis of said flow tube; walls of said case ends are curved and offset from perpendicular with respect to said cylindrical walls; an inner surface old a curved portion of said case end includes means that receives the outer radial extremity of said circular cone connect means; said flow tube and said flow tube extension extends the length of said case and through a center opening of said cone connect means and through said cavity of said neck of said case end to a flow tube extension terminus axially outward beyond said neck. Preferably said terminus of said flow tube extension is devoid of attachment to any structure axially outward from said case ends. Preferably the coriolis flowmeter further includes: an end flange coupled to said terminus of said flow tube extension lord enabling said coriolis flowmeter to be coupled to a pipeline. Preferably said case comprises: cylindrical walls oriented parallel to the longitudinal axis of said flow tube center portion; walls of said case ends have a curved portion that is offset from perpendicular with respect to said cylindrical walls; an inner surface of an axial inner portion of said case end has a diameter equal to the inner diameter of said case for receiving the outer extremity of said circular cone connect means; said flow tube and said flow lube extension extend the length of said case and said flow tube extension extend through a center opening of said cone connect means and through said cavity ol said neck to said case end to a (low tube extension terminus axially outward beyond said neck. Preferably said terminus of each said flow tube extension is devoid of attachment to any structure axially outward from said case ends. Preferably the coriolis llowmeter further includes: an end flange coupled to said terminus of said tlovv tube extension for enabling said coriolis flowmeter to be coupled to a pipeline. Preferably said coriolis flowmeter further includes: end tlange; a cylindrical opening in said end tlange in said end llange for receiving said terminus of said end portion of said tlow tube extension; a neck of said end llange has a first end integral with an axially inner portion of said end tlange and has an axially inner end connected to an axially outer end of said neck ol" said case end; said end fiange and said neck of said end llange both have a cylindrical inner surface coaxial with said flow tube extension: said cylindrical inner surface opening in said neck of said end fiange as well as in an axially inner portion of said end fiange has a diameter that is greater than the diameter of the exterior of said flow tube extension to define a void between said exterior surface of said flow tube extension and said cylindrical inner surface of said neck of said end fiange and said axially inner portion of said end fiange; and an axially outer portion of said end flange defines an axially projecting element having a center opening whose inner walls have a diameter approximate that pouf said tlow tube extension diameter for seal ably receiving the terminus portion of said flow tube extension. Preferably case connect link means comprises: a flat elongated member having a bend in a mid portion of said member to define two legs of said member that are angularly oriented with respect to each other; a radically inner end of a first one of said legs being connected to an end of said balance bar; an axially outer end of a second one of said legs being connected to a surface of said cone connect means to define a series path connecting said end of said balance bar with said inner wall of said case; said series path comprises said first and second legs of said case connect link and a portion of said cone connect means. Preferably said two legs are oriented substantially 90 degree with respect to each other; Preferably said terminus ol said flow tube is devoid of attachment to any other structure axially outward from said case ends. Preferably the coriolis flowmeter includes an end flange coupled to said terminus of said tlow tube extension for enabling said coriolis llowmeter to be coupled to a pipeline. Preferably said case connect link comprises: a flat elongated curvilinear member; a radically inner end of said curvilinear member being connected to an end of said balance bar; an axially outer end of said curvilinear member being connected to a surface of said cone connect means to deflne a series path connecting said end of said balance bar with said inner wall of said case; said series path comprises said case connect link and a portion of said cone connect means. Preferably said case connect link comprises: an elongated member having at least one bend; a first end of said elongated member is connected to an end of said balance bar; a second end of said elongated member is connected to a surface of said cone connect means to deflne a series path connecting said end of said balance bar with said inner wall of said case; said series path comprises said case connect link and a portion of said cone connect means. Preferably said cylindrical cone connect means has a radially outer portion rigidly affixed to said case ends and a radially inner portion rigidly affixed to said How tube. Another aspect is a method of forming a coriolis flowmeter: said method comprising the steps of: coupling ends of said balance bar to said flow tube with brace bar means; surrounding said llow lube and said balance bar in a case with said balance bar being substantially parallel to said flow tube center portion; coupling said balance bar to an inner wall of said case with case connect link means, said case connect link means to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to a longitudinal axis of said flow tube in said driven plane; forming a cylindrical neck on said case end having a center coaxial with said flow tube extension, said neck surrounds a flow tube of said flow tube extension that projects beyond the case end and has an inner cylindrical surface of a greater diameter than the diameter of said flow tube extension; forming a circular cavity in said neck defined by the space between the outer surface of said end portion of said flow tube extension and said cylindrical inner surface of said neck; forming a cylindrical cone connect having an outer cylindrical surface of an inner cylindrical surface: in each of said case ends; sealably coupling to said flow tube extension using cone connect; extending said llow tube and said flow tube extension for the length of said case so that said flow tube extension project through said opening in each case end at said constant diameter to a terminus of said llow tube extension beyond each said case end; the method characterized in that said method further includes: forming said coriolis flowmeter so that said terminus of each flow tube extension is devoid of attachment to any structure axially outward beyond said case end. Preferably the method includes the step of extending said llow tube at a constant diameter torn the entire length to said llow lube. Preferably the method includes the step ol" extending said flow tube extension through a cone connect element in each said case end. Preferably the method includes affixing an end flange to said terminus of said tlow tube extension. Preferably the method of further including the step ol' forming a cylindrical cone connect with a radially outer portion rigidly affixed to said case ends as well as with a radially inner portion rigidly affixed to said flow tube. The above and other objects and advantages of the invention may be better understood from a reading of the following detailed description thereof taken in conjunction with the drawings in which: FIGS. L 2. 3, 4. and 5 illustrate prior art coriolis kilometers; FIG. 6 illustrates a cross sectional view of a first preferred exemplary embodiment of the present invention; FIG. 7 illustrates a cross sectional view of another alternative exemplary preferred embodiment of the present invention and; FIG. 8 in cross section FIG. 9 illustrate yet another preferred exemplary embodiment of the present invention. FIG. 10 in cross section and FIG. 11 illustrate another preferred exemplary embodiment of the invention. FIGS. 12 and 13 correspond to FIGS. 8 and 10 devoid of (lunges, DEIAILFD DESCRIPTION Description of FIG. 1 FIG, 1 discloses coriolis tlowmeter 100 of the patent 5.473.949 to Cage. It is of the straight tube type and has a case 103 enclosing a balance bar 102. The balance bar is cylindrical and encloses love tube 101. Case 103 has end elements 104 coupled by neck elements 105 to input and output llanges 106. Element 107 is the input to the tlowmeter; element 108 is the output. Flow tube 101 has an input end 109 connected to an opening in case end 104 at element 112 which is the brace bar portion of case end 104. Brace bar portion 112 is coupled to neck element 105. On the right side, the output end 110 of flow tube 101 is coupled to the case end 104 at location 112 where case end 104 Joins neck element 105. In operation tlow tube 101 and balance bar 102 are vibrated in phase opposition by a driver (not shown). With material tlow, the vibration of tlow tube 101 induces a Coriolis response in llow tube 101 that is deflected by velocity sensors (not shown), Ice phase displacement between the velocity sensors represents information pertaining to the (lowing material. The signal output of the velocity sensors is applied to electronics circuitry that processes the signals to derive the desired information pertaining to the material llow. It is necessary that a Coriolis tlowmeter provide accurate material tlow information over a wide range of operating conditions including materials of different density, temperature and viscosity. In order to achieve this, it is necessary that the vibration of the vibrating structure of the tlowmeter be stable over this range of conditions. In order to achieve this stability it is necessary that the llovvmeter vibrations be isolated to the flow tube and balance bar elements. The reason for this is that vibration external to the vibratory system imposes additional accelerations on the material besides the Coriolis acceleration that is used to determine the How rate to the material. External vibration also moves the nodes defining the active length of How tube. The resulting acceleration is variable and subject to unknowable parameters such as mounting stiffness. The undesired additional vibration of the vibratory structure of the llovvmeter therefore impedes the ability of the llovvmeter to provide accurate output information regarding the material flow. for the tlowmeter of FIG. 1, the vibrating system includes balance bar 102 and tlow tube look which are vibrated in phase opposition. These two elements comprise a dynamically balanced structure in which the ends 111 balance bar and ends 109 and 110 of the flow tube are coupled by brace bar portion 112 of case end 104. This is undesirable since the processing of materials of different densities may cause the vibration amplitude of the balance bar 102 and the How tube 101 to vary. Description of fake. 2 FIG. 2 discloses the coriolis flowmeter of U.S. Patent 5,365J94 to Crone (FIG, 2 of U.S. Pat, No. 5.365J94). This patent discloses Coriolis flowmeter 200 having a case 203 containing a tlow tube 201 and a surrounding balance bar 202. Case 203 has a case end 204 that is coupled by a neck element 205 to end flange 206. Flow tube 201 extends through the entirety of the case and is coupled at its end 209 to portion 213 of end flange 206. Immediately to the right of flange portion 213, is a void 214, which separates the inner wall of neck element 205 from the outer surface of flow tube 20 f, Ice flowmeter of FIG. 2 differs from that of FIG. 1 in that it includes distinct brace bar 212 which couples the ends 211 of balance bar 202 to the outer surface of flow tube 201. In the flowmeter of FIG. 2, the dynamically balanced vibrating system is balance bar 202. brace bar 212 and the flow tube 201- A node (point of no vibration) normally resides in each brace bar 212. Under these conditions the meter is processing a material flow of a density for which the meter was designed and calibrated. The vibration amplitude of the balance bar 202 times its mass is then equal to the vibration amplitude of the material filled flow tube 201 times its mass. When the flowmeter encounters materials of a higher density, the vibration amplitude of the flow tube decreases and the vibration amplitude of the balance bar increases. Similarly, when materials of a lower density are encountered, the vibration amplitude of the flow tube increases and the vibration amplitude of the balance bar decreases. As the vibration amplitude ratio changes, the longitudinal axis of flow tube sections 20IL exits brace bar 212 at an angle to the flow meter. Under these conditions the balance bar applies a greater bending torque to the brace bar region than the flow tube. The bending causes the case to translate downward (in phase with the heavy flow tube) while the brace bar regions translate upward (in phase with the balance bar), these translations, as explained above can impair the accuracy of the flow meter. The unbalanced torque can also stress the meter elements and in extreme cases, it can result in a shortened life or destruction of the flowmeter. Description of FIGS. 3. 4. and 5 FIGS. 3. 4, and 5 show a left portion of the flowmeter of FPO Patent li? 0 759 542 A1 (FIG. 8b of FPO Patent IT 0 759 542 AI), The flowmeter of FIG. 3 is similar to that of FIG. 2 in that it has a case 403, a case end 404, a case neck 405 and end flanges 406. Case 403 encloses flow tube 401 which Is surrounded by balance bar 402. Brace bars 412 couple balance bar end 411 to flow tube 401. The flow tube end 407 Is connected by flow tulle end portion 410 to portion flange element 413 which is a part of flange 406. I he flowmeter of FIG. 3 is similar to that of FIG. 2 in that It has a void 414 between the exterior The tlowmeter of FIG. 3 differs from that of FIG. 2 in that flow tube end element 410 is larger in diameter than flow tube 401. The change in diameter between flow tube element 410 and flow tube 401 serves the purpose of relieving thermal stresses in the flow tube. Another distinction between the flowmeter of FIG. 3 and that of FKJ. 2 is that the flowmeter of FIG, 3 has case connect link elements 417 each of which has a first end 418 coupled to an inner wall 420 of case 403 and a second end coupled to the end 41 I of balance bar 402. Case connect links 417 overcome some of the vibration problems described for the flowmeter of FIG. 2, The tlowmeter structure of FIG. 2 permits the ends of the balance bar 202 and brace bar 212 to vibrate with respect to the inner wall of case 203, This is prevented in the flowmeter of FIG. 3 since case connect links 417 provide a rigid connection between the balance bar ends 411 and the inner wall 420 of case 403, In such structures, the location where the case connect links 417 join to the balance bar end acts as a pivot point 508 for the vibrations of flow tube 401 and balance bar 402. Thus the balance bar end cannot translate with respect to the inner wall of case 403 by virtue of the connection between the two elements provided by case connect links 417. However, as shown in FIG. 4, balance bar 402, flow tube 401 and brace bar 417 can become a dynamically unbalanced structure when materials having a significantly higher or significantly lower density than normal are processed. Ihe change in amplitude ratio of the elements to the right of pivot point 508 can apply an undesirable torque to portion 401L of the flow tube 401 resulting forces Fl and F2. , FIG. 5 is an end view of the tlowmetcr structure of FIG. 4 taken along line S-S of FIG, 4. FIG. 5 shows flow tube 401 brace bar 412, case connect links 417 having outer ends 418 connected to the inner wall 420 of case 403 and an inner end 419 connected to the outer extremity of brace bar 412. Case connect links 417 are flat strips. FIG. 3 is a top view of a section of tlowmetcr 400; FIG. 4 is a side section view. Description of FKJS. 6 and 7 FIG. 6 discloses one possible exemplary embodiment of the invention as comprising a llowmeter 700 having a case 703 that encloses the elements that comprise the vibrating system of the llowmeter. These elements include a balance bar 702 which surrounds a center portion of How tube 701. Balance bar 702 is connected at its ends lay a brace bars 709 to flow tube 701. Ihe flow tube 701 includes extensions 701F at the input end and 701R at the output end of the llowmeter. hose How tube elements together comprise a single How tube that extends at a constant diameter through the llowmeter 700. In so doing, flow tube 701 extends for the length of case 703. through case ends 704 and projects beyond case ends 704 to terminus 707 on the left and terminus 708 on the right. Clement 707 may be considered to be the input end of the (low tube; clement 708 may be considered to be the output end of the flow tube. The case ends 704 have a center portion 723 termed a cone connect having an opening through which tube portion 70IL extends on the left and through which flow tube portion 701R. extends on the right. Cone connect 723 sealably engages the exterior surface of flow elements 70IL and 70IR. Case end 704 has a thickness essentially the same as that of case 703. I he radially center portion of the case ends 704 includes a lip 722. Lip 722 extends axially outward beyond the outer surface of case end 704 and its cone connect 723. The inner surface of lip 722 has a diameter that is essentially the same as the outer diameter of cone connect 723. I he inner diameter of the lip of 722 and the outer diameter of the flow tube forms a void 721. The ends of balance bar 702 are coupled by brace bars 709 to the outer surface of How tube 701. Brace bars 709 form a path that permits balance bar 702, brace bars 709, and How tube 701 to be a dynamically balanced system with the balance bars 702 and the tlow tube 701 dynamically communicating with each other via brace bars 709. The ends of balance bars 702 are further coupled by means of case connect links 710 to the inner wall 712 of case 703. Case connect links 710 include a fold element 71 K Case connect links 710 are coupled at their outer end 706 to the inner case wall 712 and at their inner end 705 to balance bar 702. The case connect links 710 of FIG. 6 are similar to case connect links 417 on RICK 3 in that they couple the ends 705 of balance bar 702 on FIG. 6 to the inner wall 712 of case 703. Their function is to prevent vibrations of brace bar 709 in a direction perpendicular to the lube axis in the drive plane of FIG. 6. The case connect links 710 serve to keep the unbalanced torques from moving the brace bar 709 with respect to the case. This enables the vibration amplitude ratio to change with density so as to keep the vibrating structure balanced. Flow ever. as distinguished from case connect links 417, case connect links 710 have an out of plane bend. Balance bar 702 and the case 703 can change in diameter with respect to each other in response to temperature differentials between these two elements. Bend 711 permits the effective length of case connect link 710 to change as the case diameter and the balance bar diameter attempt to expand or contract with respect to each other. Driver D and a left velocity sensor FPO and a right velocity sensor RPO are shown coupled to How tube 701 on FIG. 6. these elements are connected in a manner similar to that shown in greater detail on Flu}. 7 to meter electronics clement 801. Meter electronics 801 supplies a signal via path 803 to driver D to vibrate How tube 701 to transversely at the resonant frequency odor tube 701 with material flowing therein. The combined material How and vibrations impaled to How tube 701 by driver D induces a Coriolis response in flow tube 701 in a manner well known in the art. The phase deterrence between the signals of left velocity sensor LPO and right velocity sensor RPO represents information pertaining to the material flow. The output signals of the velocity sensors are applied as shown on FIG, 7 via paths 802 and 804 to meter electronics 801 which processes the received signals and generates output information on its path 815 pertaining the material How. It should be noted that the flow tube ends 707 and 708 arc not connected to tlange elements as is the case for flowmeter of FIG. 7, The tlowmeter of FIG. 6 is manufactured, tested, and balanced without flanges being attached to the flow tube ends. The prior art meters of FIGS. 2 through 5 could not be balanced and tested prior to the flanges being attached because the tube end connections were critical to the dynamics of the vibrating structure. The cone connect elements 723 of the present invention remove the tube ends 707 and 708 from the dynamic structure of the meter and create a fully functional meter prior to the flange welding operation. Suitable facilities are provided at the location at which the flowmeter of FIG. 6 is balanced and tested to permit the flow ends 707 and 708 to be coupled to a source of material to permit the balancing and testing to be accomplished. Once this testing and balancing is accomplished, the flowmeter of FIG, 6 may be stored until it is ready for delivery to a customer. The manufacture testing, balancing and temporary storage of the flowmeter of FIG. 6 without flanges is advantageous since there are many different types of flanges. It is economically advantageous to manufacture, balance, test, and store a flowmeter in its condition as shown in FIG. 6 until such time as a customer for the .tlowmeter is known and the type of tlange desired by the customer is also known. At that time, the tlanges desired by the customer are attached and the tlow meter is equipped as shown in FIG. 7. It is advantageous to balance, test and store the flowmeter equipped as shown in FIG. 6 since it minimizes the inventoi7 that a manufacture must maintain. Description The embodiment of tlowmeter of FIG, 7 is identical to that of FIG, 6 except that the tlowmeter oil' FIG. 7 includes llangcs 806 affixed to the end portions 701L and 701R of tlow tube 701. Flanges 806 include an outer end surface 807, an inner surface 809 parallel to outer surface 807. a neck 805 having an inner axial end surface which contacts a mating outer axial end surface of lip 722 of case end 704. Outer surface 807 of llange element 806 has a raised element 827 having a center opening whose walls sealably contact flow tube 701L at its inlet 707 and 701R at outlet 708. A void 721 is defined bv the space between the exterior surface of flow tube 701 intermediate raised element 827 of flange 806 and lip 722 coupled to case end 704. Void 721 is advantageous in that it permits flange 806 to be coupled to case end 704 at lip 722. Since this coupling involves a heating operation, such as brazing or welding, flow tube 70IF and 701R is subject to less thermal stress by virtue of the void 721. If the void 721 comprised solid material, the heat from the welding of the llange 806 to lip 722 could be conducted lo and overheat the portions of flow tube flow tube 701L and 7011^. This large amount of heat could alter the structure of the flow tube material, such as titanium, in such a way as to decrease its corrosion resistance. The heat of the weld could also partially melt the braze material in the Joint between tlow tube 701 and cone connect 723. This could harm the braze and could possibly affect the prior balancing and adjustment of flowmeter in its state ol completion as shown on FIG. 6. the embodiment of llowmeter of FIJI. 7 provides three connection points between How tube 701 and case 703 near each end of How tube 70 F The first connecting point is that provided by the end flanges 806 which have the center opening of raised element 827 whose walls are bonded to flow tube ends 70IF and 701R. Fee second connecting point is cone connect 723 of case end 704. The third connecting point is provided by brace bars 709 together with case connect links 710, These three connecting points affix flow tube 701 to the structural elements to flowmeter case 703. Fee function of the connecting point comprising the case connection links 710 and the brace bar 709 is to minimize translations to the flow tube end nodes where they are coupled to brace bar 709. The function ol' the Junction point provided by raised element 827 and the walls of its center opening is to seal the How tube 701 to the flange 806 so as to prevent the material flow from entering case 703. The function provided by cone connect 723 is to provide a rigid termination for the dynamic portion of the How tube. This connection applies to the case end the force generated by unbalanced torque at the brace bar region. The case and case end are rigid enough to withstand this force without significant bending. Moving the torque reaction force (FIG. 4) to the case end eliminates communication to the vibratory structure of the flowmeter. The intermediate connection also reduces stress on the Junction between the flow tube ends 707 and 708 and raised element 827 and thereby increases reliability. Description of FIGS. 8 ,9 and 12 FIGS. 8 and 9 disclose another possible exemplary embodiment of the invention. The emlxdiment of FIG. 8 is similar to that of FIGS. 6 and 7 in that the flowmeter 900 of FIG. 8 has case 903 that encloses a balance bar 902 and a flow tube 901. FIG. 8 discloses only a left portion of llowmeter 900 to minimize drawing complexity. Also, the driver D and the two velocity sensors LPO and RPO are not shown on FIG. 8 nor is the associated kilter electronics. It is to be understood that the How meter of FIG. 8 includes a driver element D, a left velocity sensor LPO and a right velocity sensor RPO all of which are connected over appropriate conductors to a meter electronics element which applies a drive signal for the driver to vibrate the balance bar and flow tube and which receives the signals from the two velocity sensors, and processes them to generate material How information for the material flowing through flow tube 901 as it is vibrated by the driver D (not shown). In a manner similar to that shown on FIGS. 6 and 7. the left end of balance bar 902 is connected at Junction 905 to the lower end of a case connect link 910 having a fold 911 with the outer end 920 of the ease connect link 910 being connected to an inner wall 912 of case 903. Case connect link 910 performs the same function as that for case connect link 710 on FIG. 6. They similarly stabilize the vibrations of balance bar 902 and flow tube with respect to vibrations in the drive plane (perpendicular to the plane of the paper on which FIG. 8 is illustrated). Flow tube 901 extends for the lengths of balance bar 902 and further extends axially through a disc like cone connect member 923 which is shown in detail on FIG. 9. Flow tube 901 extends through an opening 926 in cone connect member 923 and further extends as element 901 L to its input end 907 where it is connected by raised element 927 to flange 906. Flange 906 has an outer axial surface 904, an outer circumferential surface 908 and an inner axial surface 909. Flange 906 has a neck 925 that is coupled by means of a weld 922 to a neck 924 of the end of case 903. Neck 924 is similar to lip 722 of the flowmeter of FIG. 6, The difference is that while the lip 722 of case end 704 is relatively small compared to case end 704, neck 924 of ease end 928 projects axially towards surface 909 of end llange 906 a greater distance than does lip 721 of FIG. 6. Void 930 defines the space between the exterior surface of How tube 901L and the inner radial surfaces of neck 925 and neck 924. Void 930 serves the same function as docs void 721 on ITG. 7; namely, it minimizes the heat that is conducted from the weld 922 to the flow tube 90IL. This protects the How tube 901L and the braze Joint of opening 926 from the heat of the tlange weld 922. Cone connect member 923 is shown in further detail on FIG. 9 as comprising a circular element having an outer circumference 932 which is coupled to a notch in the inner surface 929 of case end 928. Cone connect member 923 has a flat surface 1002 adjacent its circumference 932. Near the radial mid point the surface 1002 becomes groove 1003 which, in turn, becomes a flat surface 1005 comprising the inner radial portion of cone connect 923. The center of Hat surface 1005 has an opening 926 through which How tube 901 extends with the flow tube and surface 1005 being coupled to one another. Groove 1003 enhances the ability of the cone connect 923 to accommodate differential expansion due to temperature differences between the How tube 901 and the case 903. It also protects the completed flowmeter from excessive thermal axial stresses. The structure comprising case 903 and end flanges 906 of flowmeter 900 are coupled to the How tube at three points per end in the same manner as the llow lube of FIG. 7. the first point of coupling is that between raised element 927 and flow tube end 907. A second point of coupling is that between llow tube 901 and cone connect member 923. The third point of coupling is that provided by case connect link 910 between the inside surface of the case 903 and the end of balanced bar 902. The end of balance bar 902 is in turn connected to tlow tube 901 by the brace bar (not shown). FIG. 12 discloses the coriolis 4 llowmeter of FIG. 8 but devoid of tang 906. Description of FIGS, 10 11 and 13 FIGS. 10 and 11 disclose an alternative embodiment of the invention that is similar in many respects to that shown on FIGS. 8 and 9. Ihe two embodiments are similar in most respects and differ only with respect to the details of the elements 923 and 910 on FIG. 8 which are the cone connect element and case connect links respectively. Corresponding elements on FKJS. 10 and 11 are designated 1123 and 1110 with 1123 the cone connect element and with element 1110 being the case connect link. The elements on FICHES. 10 and 11 that have reference numbers in the 900 series (i.e. 902, 903, . , . etc.) are identical to the corresponding numbered elements of FIG. 8 which have already been described in detail in connection with FIG. 8. The elements of FIG. 10 that differ from those on Foci. 8 are designated with reference numbers in the 1100 series (i.e. 1102, 1103 . . . etc.). Cone connect element 1123 of FIG. 10 differs from its counterpart 923 on FIG. 8 in that cone connect 1123 has a larger diameter that extends from one inner surface 912 of case end 928 to the inner wall on the opposite side of the case end. Because of this, cone connect 1123 is positioned somewhat to the right on FIG. 10 and adjacent the weld portions 921 of the case 903. The cone connect 923, by way of comparison, is positioned more to the left on FIG. 8 and has its circumference recessed within notches of the inner case end wall. Cone connect 1123 is shown in greater detail on FIG. 11 and has its outer circumference 1129 contacting inner wall 912 on FIG. 10. Immediately adjacent the outer circumference 1129 is a tlat portion 1102 as shown both on FIGS. 10 and 11. The inner portion of Hat surface 1102 engages a curved surface 1103 as shown on FIGS. 10 and 11 with the curved surface 1103 having a bowl like ci)pri;'iir;iiiuii. The inner extremity of bowl like surface 1 103 becomes the outer onetime Hat surface 1104 as shown on both FIGS. 10 and 11. Flat surface I ln4 has a center opening 1126 through which flow tube 901 projects. The I like surface 1103 performs the dual function of accommodating an axially iiiovcniciK of llow tube 901 due to thermal expansion/contraction as well as ;Kcominoclaling changes in the inner diameter of case 903 due to thermal connect link 1110 is not identical to case connect link 910 on FIG. N ()n I K I. N. case connect link 910 is directly connected at its ends between the macro silica 912 of case 903 and the junction of the left end 905 of balance bar brace bar. The case connect link 1110 is different in that its has a Indy in Us middle and thereby comprises legs 1107 and 1108 with the leg 1108 Axial! 11 is lo be expressly understood that the claimed invention is not to be limited description of the preferred embodiment but encompasses other and alterations within the scope and spirit of the inventive concept. For example, although the present invention has been disclosed as comprising a part of a single straight tutee Coriolis flowmeter, it is to be understood that the present invention is not so limited and may be used with other types glorioles flowmeters including single tube flowmeters of irregular or curved configuration as well as Coriolis flowmeters having a plurality) flow tubes. Also, raised elements 827 and 927 may either be internal with their respective flanges 806 and 906 or they may be separate elements affixed to their respective flanges. In Coriolis flowmeters made of a single material such as stainless steer raised elements 827 and 927 may be integral with and formed or the same stainless steel as their respective flanges. U is sometimes desired that Coriolis flowmeters use different materials for their different parts. In such flowmeters, the flow tube mad be titanium and the case and flanges map be stainless steel. Also the raised Inserts 827 and 927 may also be titanium lo provide a flow path that is ail titanium. In such flowmeters the titanium inscrolls 827 and 927 would be separate elements from the stainless steel flanges and would be affixed to the tlanges by appropriate bonding techniques. WE CLAIM : 1. A coriolis flowmeter (700) having a How tube (701) and a balance bar (702) that are adapted, when in use, to be vibrated in phase opposition in a driven plane to generate a carioles response in said vibrating How lube representing inebriation pertaining to material lowing through said vibrating low tube, said tow tube comprises a center portion and an extension at each end; said coriolis flowmeter comprising: a case (703) surrounding said tow tube center portion and said blame bar with said balance bar being substantially parallel to and surrounding said tlow tube center portion: a first and a second axial end (704) of said case: an opening (721) in each of said case ends for receiving said Low tube extension that project beyond said case ends; said opening in said case ends is coaxial with a longitudinal axis of said flow tube extension; brace bar means (709) coupling ends of said balance bar to said tlow tube; case connect link means (710) having a first end coupled to said balance bar and having a second end coupled to an inner wall of said case; said case connect link means is effective to inhibit the movement of said brace liar and said balance bar ends in a direction perpendicular to said longitudinal axis of said flow tube in said driven plane; a cylindrical cone connect means (723) having an outer circumference coupled to said case ends and having a circular opening coaxial with said Low tube extension for seal ably receiving said flow tube extension; said cylindrical cone connect means being axially positioned between a terminus of said Ilow tube extension and said case connect link means. 2. The coriolis llowmeter as claimed in claim 1 wherein said flow tube extends the length of said case and has said flow lube extensions (701 L, 701 R) 31. The coriolis flowmeter as claimed in claim 1 wherein said cylindrical cone connect means has a radically outer portion rigidly affixed to said case ends and a racially inner portion rigidly affixed to said flow tube. 32. A method of forming a coriolis flowmeter (700) having a balance bar (702) and a flow tube (701); said method comprising the steps of: coupling ends of said balance bar to said flow tube with brace bar means (709); surrounding said flow tube and said balance bar in a case (703) with said balance bar being substantially parallel to a center portion of said flow tube; coupling said balance bar (702) to an inner wall (712) of said case with case connect link means (710). said case connect link means to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to a longitudinal axis of said flow tube in said driven plane; forming a cylindrical neck (722) on an end (704) of said case having a center coaxial with an extension of said flow tube, said neck surrounds a flow tube extension that projects beyond said case end. said neck has an inner cylindrical surface of a greater diameter than the diameter of said flow tube extension; forming a circular cavity (721) in said neck defined by the space between the outer surface of said end portion of said flow tube extension and said cylindrical inner surface of said neck: forming a cylindrical cone connect (723) having an outer cylindrical surface and an inner cylindrical surface in each of said case ends (704); seal ably coupling said cone connect (723) to said flow tube extension and to said inner surface of said neck (722): extending said flow tube and said flow tube extension for the length of said case so that said flow tube extension project through said opening in each case end at said constant diameter to a terminus of said flow tube extension beyond each said case end; the method characterized in that said method wherein forming said coriolis flowmeter so that said terminus of each flow tube extension is devoid of attachment to any structure axially outward beyond said case end.

Full Text

FIELD OF THE INVENTION
This invention relates to a coriolis flowmeter and in particular to a single tube corollas tlowmeter structure for connecting the vibrating elements of the carioles flow meter to the tlowmeter case. The invention further relates to a coriolis flowmeter that can be manufactured, tested, balanced, and stored prior to the attachment of process connection llanges.
PROBLEM
It is a problem to provide a single How tube coriolis tlowmeter that operates satisfactorily over a wide range of variations in the operating parameters of the tlowmeter. These parameters include operating temperature, the density of the material tlow as well as the material pressure and How rate. A change in material density, thermally induced stress in the tlow tube, or pressure stress on the tlow tube can each result in an unbalanced condition which effects the accuracy of the tlowmeter. Changes in these parameters degrade the static and dynamic isolation of the vibratory elements of the tlowmeter. The problem is to keep the vibratory elements immune from the effects of changes in operating parameters. The accelerations that result from the change in operating parameters impair tlowmeter accuracy lay adding to or subtracting from the coriolis acceleration of the material, fee unwanted accelerations cannot be compensated torn because they vary with the mounting conditions of the tlowmeter. In addition, the mounting conditions often change with time and temperature in unknown ways.
twin though a variation of the material parameters and mounting conditions is to be expected, it is desired that the tlowmeter remain operational and produce accurate output inebriation. It is also desired that the structural integrity of the tlowmeter elements be maintained as these parameters vary. It is a goal to design a coriolis tlowmeter so that it operates with suitable accuracy

and does not destroy itself as the flowmeter elements are subject to varying operating temperatures, flowmeter designers also desire that the flowmeter calibration will remain constant and flat over a reasonably wide range material densities.
In order to achieve these design objectives, a Coriolis flowmeter must have a dynamically balanced vibrating structure that operates in a controlled and predictable manner over a range oi^ operating parameter variations. The flowmeter elements external to the vibrating system should not vibrate or communicate vibration to the vibrator}^ system. A coriolis flowmeter often comprises a single straight flow tube surrounded by a balance bar and brace bars coupling the balance bar ends to the flow tube. In operation, vibration nodes (regions of no vibration) occur between the flow tube and the balance bar. Ice nodes define the length of the flow tube that is subject to Coriolis force. The vibration nodes of the flow tube and the surrounding balance bar should remain in the brace bars over the range of parameters for which the flowmeter is designed. Since the balance ban brace bar. and flow tube comprise a dynamically balanced system, the vibrating mass times the vibration velocity oi^ the balance bar should equal the vibrating mass limes the vibration velocity ol' the flow tube. As long as these conditions are met, and no other unbalanced forces or torques are applied to the non-vibratory elements of the flowmeter, the vibration nodes remain in the brace bars and the other flow meter elements remain free from vibration. However, prior art attempts have all fallen short of meeting these conditions.
It is a problem of prior art to provide a coriolis tlowmeler structure for which a shift of the material density does not degrade the static and dynamic isolation of the flow meter’s vibratoi7 system and the corresponding reduction in the accuracy of the meter.

It is also a problem in the manutacture. balancing and testing of a coriolis flowmeter to minimize the number of coriolis flowmeter of a given model that must be maintained in inventory. The reason for this is that there are more than twenty deliberant types of end flanges that may be coupled to each of flowmeter. There are perhaps eight different sizes of flowmeter resulting in 120 different meters that need to be stocked in order to have rapid response to sales orders. At a cost of several thousand dollars each, the amount money tied up in inventory can be significant. It is desired that flow meters be of such a design that they can be balanced, and tested before the flanges are attached. This would enable the stocking of far fewer finished meters without flanges. The desired flanges would be welded on with the receipt of each order.
SOLUTION
fee above problems are solved and an advance in the art is achieved b\ the present invention. In accordance with the present invention, three separate connection points are provided at each end of the flowmeter between the vibrating structure and the flowmeter case including the end llanges. A Loris such connection point is in the end flange where the flow tube end is joined to the end flange. A second connection point is provided by case connect links which couple the balance bar ends to the inner wall of the case.
Ice third connecting point in each end of the flowmeter is provided by a circular element termed a cone connect, 1 his third connection point is provided by bonding (usually brazing) the flow tube to the cone connect element at the flow tube location where it extends through an opening in the case end and projects axially outward towards the flow tube end. Ibis cone connect connection is. like the other two connections, of limited length in the direction of the tube axis. There is a length of unsupported flow tube between the flange connection and the cone connect and another length of unsupported How tube

between the cone connect and the case connect links. Since these unsupported portions loathe How tube are not coupled to any other structure, a void surrounds these portions of the How tube. The outermost void (in the neck of the flange) allows the welding of a (langc to the case end at this location without overheating or stressing the How tube. Also, the amount of heat required to effect a weld at these two locations is tar less than would be required if the entirety of this portion of the tlow tube was thermally coupled to the entire structure between the end llange and the case end.
The provision of three points of coupling at each end of the tlow tube to the supporting structure of the flowmeter minimizes the communication of vibrations to the vibratory structure the flowmeter that are generated by extreme conditions of parameters such as material density. It does this by the use of the case connect links to enable vibration amplitude ratio balancing and it uses the cone connect element to keep unbalanced torque away from the vibrato it structure of the flowmeter. The reduced communication of vibrations to the vibratory structure of the flowmeter increases the accuracy and reduces the effect that different mounting conditions have on the flowmeter.
In accordance with another embodiment of the present invention the coriolis flowmeter is manufactured, tested, and balanced prior to the time that the end flange is actually attached. At this stage of completion, the internal elements of the tlowmeter are fully operational and are sealed or isolated by the cone connect element. The end portions of the flow tube extend axially outward from each of the case ends and their cone connect elements. Because the case is sealed and the flow tubes are rigidly affixed to the case ends, the tube ends may be temporarily coupled to a source of material tlow at this time. The flowmeter may then be balanced. I he tlowmeter may be indefinitely stored in this state until an order is received from a customer. Then, the needs of the customer and the details of the end flanges required by the customer are made known and the

appropriate end llanges may be coupled to the How tube projections and the case ends by suitable welding operations.
The balancing and testing and subsequent temporary storage of the flowmeter prior to it being connected to end flanges is advantageous in that it minimizes the inventory that otherwise would have to be maintained by a supplier. If finished flowmeters were required to be stored with over twenty known types of llanges, the inventory would have to be enormous.
An alternative embodiment of the invention provides a case connect link that is not directly connected at its ends between the balance bar and the inner wall of the case. Instead, the case connect link has a bend in its central portion and has its outer end connected to a flat surface of the cone connect element. In this second embodiment, the cone connect link is circular as in the first embodiment but has a larger diameter with the outer circumference of this circular cone connect element engaging the inner circular surface of the flowmeter case end. By this means, the case connect link has sufficient rigidity to prevent relative motion between the balance bar ends and the inner wall of the case. At that the same time, due to the bend in the case connect link, the case connect link is able to telex and accommodate changes in the diameter of the balance bar due to thermal changes. Ice circular cone connect element functions as before described in that it has an opening in its center portion through which the flow tube extends. It differs in that the large outer diameter of the cone connect allows relative axial movement between its outer and inner connection points. This compliance can lower the thermal stress in the flow tube. The cone connect element of this embodiment, like the previous embodiment, also has sufficient rigidity in the radial direction to terminate the dynamic portion of the (low tube and allow balancing prior to flange welding. It also seals the case interior from the environment.

It can therefore be seen that the present invention is advantageous in phi it provides a flowmeter structure that maintains the dynamic isolation vibratory system of the flowmeter. It further permits the flowmeter to be tested. balanced, and stored in a state in which it is devoid of a flange: the clang chive installed only when the specific model flange required by the customer is known.
An aspect of the invention comprises a coriolis (flowmeter a How tube and a balance bar that are adapted, when in use, to be vibrated in polkas opposition in a driven plane to generate a coriolis response in said \brainy flow tube representing information pertaining to material (lowing through said vibrating flow tube, said flow tube comprises a center portion and an extension at each end; said coriolis flowmeter comprising: a case surrounding said tlow tube center portion and said balance bar being substantially parallel to and surrounding said flow tube center portion; a first and a second end of said ease: an opening in each of said case ends for receiving end portions of said How tube that project beyond said case ends: said opening in said ease ends is with a longitudinal axis of said How tube extension: brace bar means coupling ends of said balance bar to said How tulle; case connect link means hexing a first end coupled to said brace bar as well as to said balance bar and a second end coupled to an inner wall of said case: said case connect link means is effective to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to said longitudinal axis of said flow tube in said driven plane; a cylindrical cone connect means having an outer cireumleienee coupled to said case end and having a circular opening coaxial with said How tube for seal ably receiving said flow lube; and said cone connect means being axially positioned between a terminus of said flow tube and said case ennui link means.

Preferably said How tube extends the length of said case and has said flow tube extensions that project through said circular opening in said cone connect means and beyond said case ends to said terminus of said How lube extension.
Preferably said terminus of each said How lube extension is devoid o\^ attachment to any structure axially outward of said case ends
Preferably the coriolis flowmeter includes an end flange coupled to said terminus of each said flow tube extension for enabling said coriolis llowmelcr to be coupled to a material source ; a circular opening on an axial end surface of said end flange, and a wall on an inner surface of said circular opening Hal seal ably engages said flow tube extension.
Preferably the coriolis flowmeter comprises: a cylindrical neck of said case end extending axially outward from said case end: said neck has a center opening coaxial with said How tube and a cylindrical inner surface Thai surrounds a portion of said flow tulle that projects beyond said case end: said cylindrical inner surface of said neck has a greater diameter than the diameter of said flow tube; and a circular cavity in said neck defined b\ the space between said How tube and said cylindrical inner surface of said neck.
Preferably the coriolis flowmeter further includes a curved portion in a planar surface of said case connect link means.
Preferably said cone connect means has a flat surface having an plane bend to permit a change in the effective diameter of said circular cone connect means in response to changes in the diameter of the portion case end to which said cone connect means is coupled.

Preferably said second end of said case connect link means comprises a connection of said second end of case connect link means to said inner wall of said case,
Prelerably said intermediate connection means includes a surface of said cone connect means whose perimeter is connected to a surface of said inner wall of said case.
Preferably the coriolis flowmeter includes: a driver D that vibrates said flow tube center portion and said balance bar in a drive plane in phase opposition to each other, said vibrations in said drive plane and said material flow are jointly elective for inducing coriolis detlections in said tlow tube; pick off means coupled to said How tube that deflect said coriolis detlections: said pick off means generate signals representing information pertaining to said material flow in response to said detection of said coriolis detlections: and meter electronics that receive said signals from said pick off means and generates output information pertaining to said material flow.
Preferably said tlow tube and said flow tube extension at a constant diameter torn the length of said case and has said ends portions that project through said opening in said cone connect means at said constant diameter to said terminus of said How tube extension.
Preferably said terminus of each said end portion of said How tube is devoid of attachment to any structure axially outward from said case ends.
Preferably the coriolis llowmeter further includes an end (Lange coupled to said How lube extension for enabling said coriolis llowmeter to be coupled to a material source; a circular opening on an axial end of said clang. and a wall on an inner surface of said circular opening that seal ably engage said How lube extension.

Preferably the coriolis tlowmeter further includes a sealed cavity defined by space between the outer surface of said end portion of said How tube and said inner cylindrical surface of said neck of said case end and a cylindrical inner surface of a portion of said end (lange; said sealed cavity having an axiaily outer end comprising an outwardly projecting element of said Hanger seal ably engaged with said tlow tube extension: said sealed cavity having an axially inner end comprising said cone connect means.
the coriolis (lowmeter further includes and end llange; a neck of said end flange having a first end integral with said end flange and having second end connected to an axiaily outer end of said neck of said case end; a cylindrical opening in said end llangc and in said neck of said end llange for receiving said terminus of said flow tube extension: said cylindrical opening in said neck of said end flange and in a portion of said end flange has a diameter that is substantially greater than the exterior surface of said How lube extension to define a void between said exterior surface of said flow tube extension and said cylindrical inner surface of said neck of said end llange and a cylindrical inner surface of said portion of said end llange; and an axiaily outwardly projecting element in an axiaily outer surface of said end flange having a cylindrical opening whose walls have an inner diameter that seal ably receive the terminus portion of said flow tube extension.
Preferably said case includes walls parallel to the longitudinal axis of said flow tube; said case further includes said case ends affixed to ends of said walls and oriented substantially perpendicular to said cylindrical walls; the exterior surfaces of said case ends includes a neck coaxial with said opening in said case ends, said opening in said case ends receives said cone connect means and as well as a said portion of said flow tube extension which project axiaily outwards beyond said case ends, said neck has a cylindrical inner surface of a greater diameter than the exterior surface of said flow tufted extension to define a void

comprising the space between said exterior surface old said flow tube and said inner surface of said neck.
Preferably the coriolis flowmeter further includes: an end flange coupled to said terminus of said flow tube extension for enabling said coriolis flowmeter to be coupled to a pipeline:
Preferably said case comprises: cylindrical walls oriented parallel to the longitudinal axis of said flow tube; walls of said case ends are curved and offset from perpendicular with respect to said cylindrical walls; an inner surface old a curved portion of said case end includes means that receives the outer radial extremity of said circular cone connect means; said flow tube and said flow tube extension extends the length of said case and through a center opening of said cone connect means and through said cavity of said neck of said case end to a flow tube extension terminus axially outward beyond said neck.
Preferably said terminus of said flow tube extension is devoid of attachment to any structure axially outward from said case ends.
Preferably the coriolis flowmeter further includes: an end flange coupled to said terminus of said flow tube extension lord enabling said coriolis flowmeter to be coupled to a pipeline.
Preferably said case comprises: cylindrical walls oriented parallel to the longitudinal axis of said flow tube center portion; walls of said case ends have a curved portion that is offset from perpendicular with respect to said cylindrical walls; an inner surface of an axial inner portion of said case end has a diameter equal to the inner diameter of said case for receiving the outer extremity of said circular cone connect means; said flow tube and said flow lube extension extend the length of said case and said flow tube extension extend through a center

opening of said cone connect means and through said cavity ol said neck to said case end to a (low tube extension terminus axially outward beyond said neck.
Preferably said terminus of each said flow tube extension is devoid of attachment to any structure axially outward from said case ends.
Preferably the coriolis llowmeter further includes: an end flange coupled to said terminus of said tlovv tube extension for enabling said coriolis flowmeter to be coupled to a pipeline.
Preferably said coriolis flowmeter further includes: end tlange; a cylindrical opening in said end tlange in said end llange for receiving said terminus of said end portion of said tlow tube extension; a neck of said end llange has a first end integral with an axially inner portion of said end tlange and has an axially inner end connected to an axially outer end of said neck ol" said case end; said end fiange and said neck of said end llange both have a cylindrical inner surface coaxial with said flow tube extension: said cylindrical inner surface opening in said neck of said end fiange as well as in an axially inner portion of said end fiange has a diameter that is greater than the diameter of the exterior of said flow tube extension to define a void between said exterior surface of said flow tube extension and said cylindrical inner surface of said neck of said end fiange and said axially inner portion of said end fiange; and an axially outer portion of said end flange defines an axially projecting element having a center opening whose inner walls have a diameter approximate that pouf said tlow tube extension diameter for seal ably receiving the terminus portion of said flow tube extension.
Preferably case connect link means comprises: a flat elongated member having a bend in a mid portion of said member to define two legs of said member that are angularly oriented with respect to each other; a radically inner end of a first one of said legs being connected to an end of said balance bar;

an axially outer end of a second one of said legs being connected to a surface of said cone connect means to define a series path connecting said end of said balance bar with said inner wall of said case; said series path comprises said first and second legs of said case connect link and a portion of said cone connect means.
Preferably said two legs are oriented substantially 90 degree with respect to each other;
Preferably said terminus ol said flow tube is devoid of attachment to any other structure axially outward from said case ends.
Preferably the coriolis flowmeter includes an end flange coupled to said terminus of said tlow tube extension for enabling said coriolis llowmeter to be coupled to a pipeline.
Preferably said case connect link comprises: a flat elongated curvilinear member; a radically inner end of said curvilinear member being connected to an end of said balance bar; an axially outer end of said curvilinear member being connected to a surface of said cone connect means to deflne a series path connecting said end of said balance bar with said inner wall of said case; said series path comprises said case connect link and a portion of said cone connect means.
Preferably said case connect link comprises: an elongated member having at least one bend; a first end of said elongated member is connected to an end of said balance bar; a second end of said elongated member is connected to a surface of said cone connect means to deflne a series path connecting said end of said balance bar with said inner wall of said case; said series path comprises said case connect link and a portion of said cone connect means.

Preferably said cylindrical cone connect means has a radially outer portion rigidly affixed to said case ends and a radially inner portion rigidly affixed to said How tube.
Another aspect is a method of forming a coriolis flowmeter: said method comprising the steps of: coupling ends of said balance bar to said flow tube with brace bar means; surrounding said llow lube and said balance bar in a case with said balance bar being substantially parallel to said flow tube center portion; coupling said balance bar to an inner wall of said case with case connect link means, said case connect link means to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to a longitudinal axis of said flow tube in said driven plane; forming a cylindrical neck on said case end having a center coaxial with said flow tube extension, said neck surrounds a flow tube of said flow tube extension that projects beyond the case end and has an inner cylindrical surface of a greater diameter than the diameter of said flow tube extension; forming a circular cavity in said neck defined by the space between the outer surface of said end portion of said flow tube extension and said cylindrical inner surface of said neck; forming a cylindrical cone connect having an outer cylindrical surface of an inner cylindrical surface: in each of said case ends; sealably coupling to said flow tube extension using cone connect; extending said llow tube and said flow tube extension for the length of said case so that said flow tube extension project through said opening in each case end at said constant diameter to a terminus of said llow tube extension beyond each said case end; the method characterized in that said method further includes: forming said coriolis flowmeter so that said terminus of each flow tube extension is devoid of attachment to any structure axially outward beyond said case end.

Preferably the method includes the step of extending said llow tube at a constant diameter torn the entire length to said llow lube.
Preferably the method includes the step ol" extending said flow tube extension through a cone connect element in each said case end.
Preferably the method includes affixing an end flange to said terminus of said tlow tube extension.
Preferably the method of further including the step ol' forming a cylindrical cone connect with a radially outer portion rigidly affixed to said case ends as well as with a radially inner portion rigidly affixed to said flow tube.

The above and other objects and advantages of the invention may be better understood from a reading of the following detailed description thereof taken in conjunction with the drawings in which:
FIGS. L 2. 3, 4. and 5 illustrate prior art coriolis kilometers;
FIG. 6 illustrates a cross sectional view of a first preferred exemplary embodiment of the present invention;
FIG. 7 illustrates a cross sectional view of another alternative exemplary preferred embodiment of the present invention and;
FIG. 8 in cross section FIG. 9 illustrate yet another preferred exemplary embodiment of the present invention.
FIG. 10 in cross section and FIG. 11 illustrate another preferred exemplary embodiment of the invention.

FIGS. 12 and 13 correspond to FIGS. 8 and 10 devoid of (lunges,
DEIAILFD DESCRIPTION
Description of FIG. 1
FIG, 1 discloses coriolis tlowmeter 100 of the patent 5.473.949 to Cage. It is of the straight tube type and has a case 103 enclosing a balance bar 102. The balance bar is cylindrical and encloses love tube 101. Case 103 has end elements 104 coupled by neck elements 105 to input and output llanges 106. Element 107 is the input to the tlowmeter; element 108 is the output. Flow tube 101 has an input end 109 connected to an opening in case end 104 at element 112 which is the brace bar portion of case end 104. Brace bar portion 112 is coupled to neck element 105. On the right side, the output end 110 of flow tube 101 is coupled to the case end 104 at location 112 where case end 104 Joins neck element 105.
In operation tlow tube 101 and balance bar 102 are vibrated in phase opposition by a driver (not shown). With material tlow, the vibration of tlow tube 101 induces a Coriolis response in llow tube 101 that is deflected by velocity sensors (not shown), Ice phase displacement between the velocity sensors represents information pertaining to the (lowing material. The signal output of the velocity sensors is applied to electronics circuitry that processes the signals to derive the desired information pertaining to the material llow.
It is necessary that a Coriolis tlowmeter provide accurate material tlow information over a wide range of operating conditions including materials of different density, temperature and viscosity. In order to achieve this, it is necessary that the vibration of the vibrating structure of the tlowmeter be stable over this range of conditions. In order to achieve this stability it is necessary that

the llovvmeter vibrations be isolated to the flow tube and balance bar elements. The reason for this is that vibration external to the vibratory system imposes additional accelerations on the material besides the Coriolis acceleration that is used to determine the How rate to the material. External vibration also moves the nodes defining the active length of How tube. The resulting acceleration is variable and subject to unknowable parameters such as mounting stiffness. The undesired additional vibration of the vibratory structure of the llovvmeter therefore impedes the ability of the llovvmeter to provide accurate output information regarding the material flow.
for the tlowmeter of FIG. 1, the vibrating system includes balance bar 102 and tlow tube look which are vibrated in phase opposition. These two elements comprise a dynamically balanced structure in which the ends 111 balance bar and ends 109 and 110 of the flow tube are coupled by brace bar portion 112 of case end 104. This is undesirable since the processing of materials of different densities may cause the vibration amplitude of the balance bar 102 and the How tube 101 to vary.
Description of fake. 2
FIG. 2 discloses the coriolis flowmeter of U.S. Patent 5,365J94 to Crone (FIG, 2 of U.S. Pat, No. 5.365J94). This patent discloses Coriolis flowmeter 200 having a case 203 containing a tlow tube 201 and a surrounding balance bar 202. Case 203 has a case end 204 that is coupled by a neck element 205 to end flange 206. Flow tube 201 extends through the entirety of the case and is coupled at its end 209 to portion 213 of end flange 206. Immediately to the right of flange portion 213, is a void 214, which separates the inner wall of neck element 205 from the outer surface of flow tube 20 f,
Ice flowmeter of FIG. 2 differs from that of FIG. 1 in that it includes distinct brace bar 212 which couples the ends 211 of balance bar 202 to the

outer surface of flow tube 201. In the flowmeter of FIG. 2, the dynamically balanced vibrating system is balance bar 202. brace bar 212 and the flow tube 201- A node (point of no vibration) normally resides in each brace bar 212. Under these conditions the meter is processing a material flow of a density for which the meter was designed and calibrated. The vibration amplitude of the balance bar 202 times its mass is then equal to the vibration amplitude of the material filled flow tube 201 times its mass. When the flowmeter encounters materials of a higher density, the vibration amplitude of the flow tube decreases and the vibration amplitude of the balance bar increases. Similarly, when materials of a lower density are encountered, the vibration amplitude of the flow tube increases and the vibration amplitude of the balance bar decreases. As the vibration amplitude ratio changes, the longitudinal axis of flow tube sections 20IL exits brace bar 212 at an angle to the flow meter. Under these conditions the balance bar applies a greater bending torque to the brace bar region than the flow tube. The bending causes the case to translate downward (in phase with the heavy flow tube) while the brace bar regions translate upward (in phase with the balance bar), these translations, as explained above can impair the accuracy of the flow meter. The unbalanced torque can also stress the meter elements and in extreme cases, it can result in a shortened life or destruction of the flowmeter.
Description of FIGS. 3. 4. and 5
FIGS. 3. 4, and 5 show a left portion of the flowmeter of FPO Patent li? 0 759 542 A1 (FIG. 8b of FPO Patent IT 0 759 542 AI), The flowmeter of FIG. 3 is similar to that of FIG. 2 in that it has a case 403, a case end 404, a case neck 405 and end flanges 406. Case 403 encloses flow tube 401 which Is surrounded by balance bar 402. Brace bars 412 couple balance bar end 411 to flow tube 401. The flow tube end 407 Is connected by flow tulle end portion 410 to portion flange element 413 which is a part of flange 406. I he flowmeter of FIG. 3 is similar to that of FIG. 2 in that It has a void 414 between the exterior

The tlowmeter of FIG. 3 differs from that of FIG. 2 in that flow tube end element 410 is larger in diameter than flow tube 401. The change in diameter between flow tube element 410 and flow tube 401 serves the purpose of relieving thermal stresses in the flow tube. Another distinction between the flowmeter of FIG. 3 and that of FKJ. 2 is that the flowmeter of FIG, 3 has case connect link elements 417 each of which has a first end 418 coupled to an inner wall 420 of case 403 and a second end coupled to the end 41 I of balance bar 402.
Case connect links 417 overcome some of the vibration problems described for the flowmeter of FIG. 2, The tlowmeter structure of FIG. 2 permits the ends of the balance bar 202 and brace bar 212 to vibrate with respect to the inner wall of case 203, This is prevented in the flowmeter of FIG. 3 since case connect links 417 provide a rigid connection between the balance bar ends 411 and the inner wall 420 of case 403, In such structures, the location where the case connect links 417 join to the balance bar end acts as a pivot point 508 for the vibrations of flow tube 401 and balance bar 402. Thus the balance bar end cannot translate with respect to the inner wall of case 403 by virtue of the connection between the two elements provided by case connect links 417. However, as shown in FIG. 4, balance bar 402, flow tube 401 and brace bar 417 can become a dynamically unbalanced structure when materials having a significantly higher or significantly lower density than normal are processed. Ihe change in amplitude ratio of the elements to the right of pivot point 508 can apply an undesirable torque to portion 401L of the flow tube 401 resulting forces Fl and F2.

, FIG. 5 is an end view of the tlowmetcr structure of FIG. 4 taken along line S-S of FIG, 4. FIG. 5 shows flow tube 401 brace bar 412, case connect links 417 having outer ends 418 connected to the inner wall 420 of case 403 and an inner end 419 connected to the outer extremity of brace bar 412. Case connect links 417 are flat strips. FIG. 3 is a top view of a section of tlowmetcr 400; FIG. 4 is a side section view.
Description of FKJS. 6 and 7
FIG. 6 discloses one possible exemplary embodiment of the invention as comprising a llowmeter 700 having a case 703 that encloses the elements that comprise the vibrating system of the llowmeter. These elements include a balance bar 702 which surrounds a center portion of How tube 701. Balance bar 702 is connected at its ends lay a brace bars 709 to flow tube 701. Ihe flow tube 701 includes extensions 701F at the input end and 701R at the output end of the llowmeter. hose How tube elements together comprise a single How tube that extends at a constant diameter through the llowmeter 700. In so doing, flow tube 701 extends for the length of case 703. through case ends 704 and projects beyond case ends 704 to terminus 707 on the left and terminus 708 on the right. Clement 707 may be considered to be the input end of the (low tube; clement 708 may be considered to be the output end of the flow tube. The case ends 704 have a center portion 723 termed a cone connect having an opening through which tube portion 70IL extends on the left and through which flow tube portion 701R. extends on the right. Cone connect 723 sealably engages the exterior surface of flow elements 70IL and 70IR. Case end 704 has a thickness essentially the same as that of case 703. I he radially center portion of the case ends 704 includes a lip 722. Lip 722 extends axially outward beyond the outer surface of case end 704 and its cone connect 723. The inner surface of lip 722 has a diameter that is essentially the same as the outer diameter of cone

connect 723. I he inner diameter of the lip of 722 and the outer diameter of the flow tube forms a void 721.
The ends of balance bar 702 are coupled by brace bars 709 to the outer surface of How tube 701. Brace bars 709 form a path that permits balance bar 702, brace bars 709, and How tube 701 to be a dynamically balanced system with the balance bars 702 and the tlow tube 701 dynamically communicating with each other via brace bars 709. The ends of balance bars 702 are further coupled by means of case connect links 710 to the inner wall 712 of case 703. Case connect links 710 include a fold element 71 K Case connect links 710 are coupled at their outer end 706 to the inner case wall 712 and at their inner end 705 to balance bar 702.
The case connect links 710 of FIG. 6 are similar to case connect links 417 on RICK 3 in that they couple the ends 705 of balance bar 702 on FIG. 6 to the inner wall 712 of case 703. Their function is to prevent vibrations of brace bar 709 in a direction perpendicular to the lube axis in the drive plane of FIG. 6. The case connect links 710 serve to keep the unbalanced torques from moving the brace bar 709 with respect to the case. This enables the vibration amplitude ratio to change with density so as to keep the vibrating structure balanced. Flow ever. as distinguished from case connect links 417, case connect links 710 have an out of plane bend. Balance bar 702 and the case 703 can change in diameter with respect to each other in response to temperature differentials between these two elements. Bend 711 permits the effective length of case connect link 710 to change as the case diameter and the balance bar diameter attempt to expand or contract with respect to each other.
Driver D and a left velocity sensor FPO and a right velocity sensor RPO are shown coupled to How tube 701 on FIG. 6. these elements are connected in a manner similar to that shown in greater detail on Flu}. 7 to meter electronics

clement 801. Meter electronics 801 supplies a signal via path 803 to driver D to vibrate How tube 701 to transversely at the resonant frequency odor tube 701 with material flowing therein. The combined material How and vibrations impaled to How tube 701 by driver D induces a Coriolis response in flow tube 701 in a manner well known in the art. The phase deterrence between the signals of left velocity sensor LPO and right velocity sensor RPO represents information pertaining to the material flow. The output signals of the velocity sensors are applied as shown on FIG, 7 via paths 802 and 804 to meter electronics 801 which processes the received signals and generates output information on its path 815 pertaining the material How.
It should be noted that the flow tube ends 707 and 708 arc not connected to tlange elements as is the case for flowmeter of FIG. 7, The tlowmeter of FIG. 6 is manufactured, tested, and balanced without flanges being attached to the flow tube ends. The prior art meters of FIGS. 2 through 5 could not be balanced and tested prior to the flanges being attached because the tube end connections were critical to the dynamics of the vibrating structure. The cone connect elements 723 of the present invention remove the tube ends 707 and 708 from the dynamic structure of the meter and create a fully functional meter prior to the flange welding operation.
Suitable facilities are provided at the location at which the flowmeter of FIG. 6 is balanced and tested to permit the flow ends 707 and 708 to be coupled to a source of material to permit the balancing and testing to be accomplished. Once this testing and balancing is accomplished, the flowmeter of FIG, 6 may be stored until it is ready for delivery to a customer. The manufacture testing, balancing and temporary storage of the flowmeter of FIG. 6 without flanges is advantageous since there are many different types of flanges. It is economically advantageous to manufacture, balance, test, and store a flowmeter in its condition as shown in FIG. 6 until such time as a customer for

the .tlowmeter is known and the type of tlange desired by the customer is also known. At that time, the tlanges desired by the customer are attached and the tlow meter is equipped as shown in FIG. 7. It is advantageous to balance, test and store the flowmeter equipped as shown in FIG. 6 since it minimizes the inventoi7 that a manufacture must maintain.
Description
The embodiment of tlowmeter of FIG, 7 is identical to that of FIG, 6 except that the tlowmeter oil' FIG. 7 includes llangcs 806 affixed to the end portions 701L and 701R of tlow tube 701. Flanges 806 include an outer end surface 807, an inner surface 809 parallel to outer surface 807. a neck 805 having an inner axial end surface which contacts a mating outer axial end surface of lip 722 of case end 704. Outer surface 807 of llange element 806 has a raised element 827 having a center opening whose walls sealably contact flow tube 701L at its inlet 707 and 701R at outlet 708. A void 721 is defined bv the space between the exterior surface of flow tube 701 intermediate raised element 827 of flange 806 and lip 722 coupled to case end 704. Void 721 is advantageous in that it permits flange 806 to be coupled to case end 704 at lip 722. Since this coupling involves a heating operation, such as brazing or welding, flow tube 70IF and 701R is subject to less thermal stress by virtue of the void 721. If the void 721 comprised solid material, the heat from the welding of the llange 806 to lip 722 could be conducted lo and overheat the portions of flow tube flow tube 701L and 7011^. This large amount of heat could alter the structure of the flow tube material, such as titanium, in such a way as to decrease its corrosion resistance. The heat of the weld could also partially melt the braze material in the Joint between tlow tube 701 and cone connect 723. This could harm the braze and could possibly affect the prior balancing and adjustment of flowmeter in its state ol completion as shown on FIG. 6.

the embodiment of llowmeter of FIJI. 7 provides three connection points between How tube 701 and case 703 near each end of How tube 70 F The first connecting point is that provided by the end flanges 806 which have the center opening of raised element 827 whose walls are bonded to flow tube ends 70IF and 701R. Fee second connecting point is cone connect 723 of case end 704. The third connecting point is provided by brace bars 709 together with case connect links 710, These three connecting points affix flow tube 701 to the structural elements to flowmeter case 703.
Fee function of the connecting point comprising the case connection links 710 and the brace bar 709 is to minimize translations to the flow tube end nodes where they are coupled to brace bar 709. The function ol' the Junction point provided by raised element 827 and the walls of its center opening is to seal the How tube 701 to the flange 806 so as to prevent the material flow from entering case 703. The function provided by cone connect 723 is to provide a rigid termination for the dynamic portion of the How tube. This connection applies to the case end the force generated by unbalanced torque at the brace bar region. The case and case end are rigid enough to withstand this force without significant bending. Moving the torque reaction force (FIG. 4) to the case end eliminates communication to the vibratory structure of the flowmeter. The intermediate connection also reduces stress on the Junction between the flow tube ends 707 and 708 and raised element 827 and thereby increases reliability.
Description of FIGS. 8 ,9 and 12
FIGS. 8 and 9 disclose another possible exemplary embodiment of the invention. The emlxdiment of FIG. 8 is similar to that of FIGS. 6 and 7 in that the flowmeter 900 of FIG. 8 has case 903 that encloses a balance bar 902 and a flow tube 901. FIG. 8 discloses only a left portion of llowmeter 900 to minimize drawing complexity. Also, the driver D and the two velocity sensors LPO and

RPO are not shown on FIG. 8 nor is the associated kilter electronics. It is to be understood that the How meter of FIG. 8 includes a driver element D, a left velocity sensor LPO and a right velocity sensor RPO all of which are connected over appropriate conductors to a meter electronics element which applies a drive signal for the driver to vibrate the balance bar and flow tube and which receives the signals from the two velocity sensors, and processes them to generate material How information for the material flowing through flow tube 901 as it is vibrated by the driver D (not shown).
In a manner similar to that shown on FIGS. 6 and 7. the left end of balance bar 902 is connected at Junction 905 to the lower end of a case connect link 910 having a fold 911 with the outer end 920 of the ease connect link 910 being connected to an inner wall 912 of case 903. Case connect link 910 performs the same function as that for case connect link 710 on FIG. 6. They similarly stabilize the vibrations of balance bar 902 and flow tube with respect to vibrations in the drive plane (perpendicular to the plane of the paper on which FIG. 8 is illustrated).
Flow tube 901 extends for the lengths of balance bar 902 and further extends axially through a disc like cone connect member 923 which is shown in detail on FIG. 9. Flow tube 901 extends through an opening 926 in cone connect member 923 and further extends as element 901 L to its input end 907 where it is connected by raised element 927 to flange 906. Flange 906 has an outer axial surface 904, an outer circumferential surface 908 and an inner axial surface 909.
Flange 906 has a neck 925 that is coupled by means of a weld 922 to a neck 924 of the end of case 903. Neck 924 is similar to lip 722 of the flowmeter of FIG. 6, The difference is that while the lip 722 of case end 704 is relatively small compared to case end 704, neck 924 of ease end 928 projects axially

towards surface 909 of end llange 906 a greater distance than does lip 721 of FIG. 6.
Void 930 defines the space between the exterior surface of How tube 901L and the inner radial surfaces of neck 925 and neck 924. Void 930 serves the same function as docs void 721 on ITG. 7; namely, it minimizes the heat that is conducted from the weld 922 to the flow tube 90IL. This protects the How tube 901L and the braze Joint of opening 926 from the heat of the tlange weld 922.
Cone connect member 923 is shown in further detail on FIG. 9 as comprising a circular element having an outer circumference 932 which is coupled to a notch in the inner surface 929 of case end 928. Cone connect member 923 has a flat surface 1002 adjacent its circumference 932. Near the radial mid point the surface 1002 becomes groove 1003 which, in turn, becomes a flat surface 1005 comprising the inner radial portion of cone connect 923. The center of Hat surface 1005 has an opening 926 through which How tube 901 extends with the flow tube and surface 1005 being coupled to one another. Groove 1003 enhances the ability of the cone connect 923 to accommodate differential expansion due to temperature differences between the How tube 901 and the case 903. It also protects the completed flowmeter from excessive thermal axial stresses.
The structure comprising case 903 and end flanges 906 of flowmeter 900 are coupled to the How tube at three points per end in the same manner as the llow lube of FIG. 7. the first point of coupling is that between raised element 927 and flow tube end 907. A second point of coupling is that between llow tube 901 and cone connect member 923. The third point of coupling is that provided by case connect link 910 between the inside surface of the case 903 and the end of balanced bar 902. The end of balance bar 902 is in turn connected

to tlow tube 901 by the brace bar (not shown). FIG. 12 discloses the coriolis
4
llowmeter of FIG. 8 but devoid of tang 906.
Description of FIGS, 10 11 and 13
FIGS. 10 and 11 disclose an alternative embodiment of the invention that is similar in many respects to that shown on FIGS. 8 and 9. Ihe two embodiments are similar in most respects and differ only with respect to the details of the elements 923 and 910 on FIG. 8 which are the cone connect element and case connect links respectively. Corresponding elements on FKJS. 10 and 11 are designated 1123 and 1110 with 1123 the cone connect element and with element 1110 being the case connect link.
The elements on FICHES. 10 and 11 that have reference numbers in the 900 series (i.e. 902, 903, . , . etc.) are identical to the corresponding numbered elements of FIG. 8 which have already been described in detail in connection with FIG. 8. The elements of FIG. 10 that differ from those on Foci. 8 are designated with reference numbers in the 1100 series (i.e. 1102, 1103 . . . etc.).
Cone connect element 1123 of FIG. 10 differs from its counterpart 923 on FIG. 8 in that cone connect 1123 has a larger diameter that extends from one inner surface 912 of case end 928 to the inner wall on the opposite side of the case end. Because of this, cone connect 1123 is positioned somewhat to the right on FIG. 10 and adjacent the weld portions 921 of the case 903. The cone connect 923, by way of comparison, is positioned more to the left on FIG. 8 and has its circumference recessed within notches of the inner case end wall. Cone connect 1123 is shown in greater detail on FIG. 11 and has its outer circumference 1129 contacting inner wall 912 on FIG. 10. Immediately adjacent the outer circumference 1129 is a tlat portion 1102 as shown both on FIGS. 10 and 11. The inner portion of Hat surface 1102 engages a curved surface 1103 as shown on FIGS. 10 and 11 with the curved surface 1103 having a bowl like

ci)pri;'iir;iiiuii. The inner extremity of bowl like surface 1 103 becomes the outer onetime Hat surface 1104 as shown on both FIGS. 10 and 11. Flat surface I ln4 has a center opening 1126 through which flow tube 901 projects. The I like surface 1103 performs the dual function of accommodating an axially iiiovcniciK of llow tube 901 due to thermal expansion/contraction as well as ;Kcominoclaling changes in the inner diameter of case 903 due to thermal
connect link 1110 is not identical to case connect link 910 on FIG. N ()n I K I. N. case connect link 910 is directly connected at its ends between the macro silica 912 of case 903 and the junction of the left end 905 of balance bar brace bar. The case connect link 1110 is different in that its has a Indy in Us middle and thereby comprises legs 1107 and 1108 with the leg 1108 Axial!
11 is lo be expressly understood that the claimed invention is not to be limited description of the preferred embodiment but encompasses other and alterations within the scope and spirit of the inventive

concept. For example, although the present invention has been disclosed as comprising a part of a single straight tutee Coriolis flowmeter, it is to be understood that the present invention is not so limited and may be used with other types glorioles flowmeters including single tube flowmeters of irregular or curved configuration as well as Coriolis flowmeters having a plurality) flow tubes. Also, raised elements 827 and 927 may either be internal with their respective flanges 806 and 906 or they may be separate elements affixed to their respective flanges. In Coriolis flowmeters made of a single material such as stainless steer raised elements 827 and 927 may be integral with and formed or the same stainless steel as their respective flanges. U is sometimes desired that Coriolis flowmeters use different materials for their different parts. In such flowmeters, the flow tube mad be titanium and the case and flanges map be stainless steel. Also the raised Inserts 827 and 927 may also be titanium lo provide a flow path that is ail titanium. In such flowmeters the titanium inscrolls 827 and 927 would be separate elements from the stainless steel flanges and would be affixed to the tlanges by appropriate bonding techniques.

WE CLAIM :
1. A coriolis flowmeter (700) having a How tube (701) and a balance bar
(702) that are adapted, when in use, to be vibrated in phase opposition in a
driven plane to generate a carioles response in said vibrating How lube
representing inebriation pertaining to material lowing through said vibrating
low tube, said tow tube comprises a center portion and an extension at each
end; said coriolis flowmeter comprising: a case (703) surrounding said tow
tube center portion and said blame bar with said balance bar being
substantially parallel to and surrounding said tlow tube center portion: a first
and a second axial end (704) of said case: an opening (721) in each of said case
ends for receiving said Low tube extension that project beyond said case ends;
said opening in said case ends is coaxial with a longitudinal axis of said flow tube extension; brace bar means (709) coupling ends of said balance bar to said tlow tube; case connect link means (710) having a first end coupled to said balance bar and having a second end coupled to an inner wall of said case; said case connect link means is effective to inhibit the movement of said brace liar and said balance bar ends in a direction perpendicular to said longitudinal axis of said flow tube in said driven plane; a cylindrical cone connect means (723) having an outer circumference coupled to said case ends and having a circular opening coaxial with said Low tube extension for seal ably receiving said flow tube extension; said cylindrical cone connect means being axially positioned between a terminus of said Ilow tube extension and said case connect link means.
2. The coriolis llowmeter as claimed in claim 1 wherein said flow tube
extends the length of said case and has said flow lube extensions (701 L, 701 R)

31. The coriolis flowmeter as claimed in claim 1 wherein said cylindrical cone connect means has a radically outer portion rigidly affixed to said case ends and a racially inner portion rigidly affixed to said flow tube.
32. A method of forming a coriolis flowmeter (700) having a balance bar (702) and a flow tube (701); said method comprising the steps of: coupling ends of said balance bar to said flow tube with brace bar means (709); surrounding said flow tube and said balance bar in a case (703) with said balance bar being substantially parallel to a center portion of said flow tube; coupling said balance bar (702) to an inner wall (712) of said case with case connect link means (710). said case connect link means to inhibit the movement of said brace bar and said balance bar ends in a direction perpendicular to a longitudinal axis of said flow tube in said driven plane; forming a cylindrical neck (722) on an end (704) of said case having a center coaxial with an extension of said flow tube, said neck surrounds a flow tube extension that projects beyond said case end. said neck has an inner cylindrical surface of a greater diameter than the diameter of said flow tube extension; forming a circular cavity (721) in said neck defined by the space between the outer surface of said end portion of said flow tube extension and said cylindrical inner surface of said neck: forming a cylindrical cone connect (723) having an outer cylindrical surface and an inner cylindrical surface in each of said case ends (704); seal ably coupling said cone connect (723) to said flow tube extension and to said inner surface of said neck (722): extending said flow tube and said flow tube extension for the length of said case so that said flow tube extension project through said opening in each case end at said constant diameter to a terminus of said flow tube extension beyond each said case end; the method characterized in that said method wherein forming said coriolis flowmeter so that said terminus of each flow tube extension is devoid of attachment to any structure axially outward beyond said case end.

Documents:

in-pct-2002-071-che-abstract.pdf

in-pct-2002-071-che-claims filed.pdf

in-pct-2002-071-che-claims granted.pdf

in-pct-2002-071-che-correspondnece-others.pdf

in-pct-2002-071-che-correspondnece-po.pdf

in-pct-2002-071-che-description(complete)filed.pdf

in-pct-2002-071-che-description(complete)granted.pdf

in-pct-2002-071-che-drawings.pdf

in-pct-2002-071-che-form 1.pdf

in-pct-2002-071-che-form 26.pdf

in-pct-2002-071-che-form 3.pdf

in-pct-2002-071-che-form 5.pdf

in-pct-2002-071-che-other document.pdf

in-pct-2002-071-che-pct.pdf

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Patent Number

212348

Indian Patent Application Number

IN/PCT/2002/71/CHE

PG Journal Number

07/2008

Publication Date

15-Feb-2008

Grant Date

03-Dec-2007

Date of Filing

11-Jan-2002

Name of Patentee

MICRO MOTION, INC

Applicant Address

7070 Winchester Circle, Boulder, Colorado 80301,

Inventors:

#	Inventor's Name	Inventor's Address
1	VAN CLEVE, Craig, Brainerd	2921 Stagecoach Trail PO Box 1382, Lyons, CO 80540,
2	LANHAM, Gregory, Treat	1249 3rd Avenue Longmont, CO 80501
3	OLLILA, Curtis, John;	13508 Vallejo Street Westminster, CO 80234
4	LISTER, Ernest, Dale;	10444 Independence Circle Westminster, CO 80021

PCT International Classification Number

G01F 1/84

PCT International Application Number

PCT/US00/16103

PCT International Filing date

2000-06-13

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	09/345,075	1999-06-30	U.S.A.