|Title of Invention||
A DRIVE BELT FOR THE FLATS OF AREVOLVING FLAT CARD
|Abstract||Accordingly, the present invention relates to a drive belt for the flats of a revolving flat card in which the belt is provided with connecting element which are forming integral parte of a flexible belt and are arranged in pairs in such a maimer that a pair of elements can be taken in an element 226 of the flat, a snap-on connection being formed, characterised in that each element comprises a transverse rib provided with an inclined surface, and in that the inclined surfaces of a pair of ribs are oriented in mutually opposed longitudinal directions of the flexible belt, and in that, as the belt is extended straight, the angle (a) enclosed between each inclined surface and the surface of the belt neighbouring it, ranges from 60 to 80 degrees. PRICE: THIRTY RUPEES|
|Full Text||The invention concerns a connection between a flat and a flexible drive belt in a flat arrangement of a revolving flat card. A connection of such type is shown in the European Patent Application EP-A-627507.
The belt according to EP-A-627507 comprises fixing elements provided in pairs, each element being provided with a connecting part formed as an integral part of an elongated belt body and a foot part separated from the belt body, in which ar¬rangement each foot part can act as a holder for a corresponding counterpart provided on the flat. In a preferred embodiment each pair of elements forms a snap-on connection acting on the counterparts on the flat.
It is the goal of the present invention to propose solutions in which in a connec¬tion of the type mentioned contradicting goals can be achieved, namely that on one hand the flat remains rigidly fixed in a predetermined position on the drive belt during operation of the revolving flat arrangement, and that on the other hand the flat can be removed and re-connected to the belt if needed (e.g. for maintenance purposes).
Solutions for this task can be seen from the characterizing part of the patent claim 1.
The advantages of the present invention are seen in particular in that no addi¬tional mechanical guides are required for flat deflection and that a simple and practical connection is ensured for the flats on the drive belt during operation. The flats easily can be taken off the drive belt and can be exchanged. The inven¬tive solution is applicable not merely to the known flats provided with block-shap¬ed heads, but e.g. also to flats provided with rod-shaped gliding pins, e.g. accor¬ding to EP-A-567747.
The flat of a revolving flat card comprises a clothing support element which is to be connected to the drive belt. The flat can comprise heads at its ends which are to be connected to the clothing support element as well as to the drive belt.
The invention is applicable in any case with a flat the clothing support element of which it is formed as a hollow profile provided with end heads which are formed separately and connected to the hollow profile. A flat of such type is described e.g. in US-A-4827573 and there consists of a steel tube drawn through a profiling template. At both ends of the flat a solid end head each is provided for the connection to a drive belt. These head ends are connected to the flat by either welding, rivets or bolts in such a manner that they can be replaced if they are worn out. A preferred solution of the latter problem is shown in EP-A-627507 (Figures 8 through 11) and is applicable in the context of the present invention also. In particular this type of connection is advantageous if the flats are made from hollow profiles of light metal such as aluminium or similar metals.
Accordingly, the present invention provides a drive belt for the flats of a revolving flat card in which the belt is provided with connecting elements which are forming integral parts of a flexible belt and are arranged in pairs in such a manner that a pair of elements can be taken up in an element 226 of the flat, a snap-on connection being formed, characterised in that each element comprises a transverse rib provided with an inclined surface, and in that the inclined surfaces of a pair of ribs are oriented in mutually opposed longitudinal directions of the flexible belt, and in that, as the belt is extended straight, the angle (a) enclosed between each inclined surface and the surface of the belt neighbouring it, ranges from 60 to 80 degrees.
Further advantages of the present invention are indicated in the following des¬cription, in which the invention is explained in more detail with reference to illu¬strated design examples, on the basis of a solution according to EP-A-627507 which solution thus is described first. It is shown in:
Fig. 1 a schematic side view of a revolving flat card.
Fig. 2 a schematic view of a portion of a revolving flat arrangement of a card according to Fig. 1,
Fig. 3 an axonometric view of the preferred embodiment according to EP-A-627507 in a copy of the Fig. 12 from said EP-A-627507,
Fig. 4 an axonometric view of a drive belt according to the present invention.
Fig. 5 a side view of the belt according to Fig. 4 with a pair of connecting ele¬ments according to the present invention,
Fig. 6 a front view of a flat with an end head shown in a cross-sectional view and provided to co-operate with the elements according to Fig. 5 shown in a cross-section,
Fig. 7 a top view of the end head according to Fig. 6,
Fig. 8 a longitudinal section of a drive belt according to Fig. 5 with an end head according to Fig. 7 supported thereon,
Fig. 9 a cross-section of a drive belt according to Fig. 5 bent in such a direction that the holding forces of the fixing elements are increased,
Fig. 10 a cross-sectional view of the element according to Fig. 7 being brought into contact with a belt according to Fig. 5,
Fig. 11 a cross-sectional view of the belt according to Fig. 5 bent in such a direc¬tion that the distance between the fixing elements is reduced,
Fig. 12 a schematic side view of the guide elements for a drive belt of the re¬volving flat arrangement explaining the bending action shown in Fig. 11, and in
Fig. 13 a schematic side view of a modification of the arrangement according to Fig. 12.
In Fig. 1 a revolving flat card 1, known as such, is shown, e.g. the card model C 50 of the applicant. The fibre material in the form of opened and cleaned fibre flocks is fed to the feed chute 2 and taken in by a breaker roll (or taker-in roll) 3 as a fibre layer, then is transferred to a main carding cylinder 4 (or drum) and pa¬rallelized by a set of revolving flats 5 which, driven around deflecting rolls 6, mov¬es in the same direction or in the opposite direction of the rotation of the cylinder 4. Fibres from the fibre web on the cylinder 4 thereupon are taken over by a take¬off roll 7 and in a web supply arrangement 8 consisting of several rolls are arr¬anged in form of a card sliver 9. This card sliver 9 then is deposited into a trans¬porting can 110 in cycloid layers by a sliver deposition device 100.
In Fig. 2 the flexible arch 120 of a card of this type is shown partially with revolv-
ing flats 13 (two of them merely being shown) slowly moving thereon driven by a toothed (or power grip) belt 14 and a drive mechanism not shown here in the di¬rection of the of the cylinder rotation or in the opposite direction. On this flexible arch 120 setting elements 15 are provided permitting the setting of the clearance between the revolving flats and the carding cylinder surface, the so called card¬ing clearance. The design of a setting element a such type on the flexible arch are known e.g. from the German utility model DE-U-931633 by the applicant for the present invention. In that case the setting elements 15 can be set not just manually but also automatically by activators such as e.g. small setting motors 17. Details of this system are described in CH-2402/94 applied for on July 29, 1994 (Obj. 2497) and thus are not repeated here.
The set of revolving flats according to DE-A-3835776 comprises e.g. 106 flats, 41 of which are in working position I.e. in contact with the gliding guide. In Fig. 3 the preferred embodiment according to EP-A-627507 is shown of the connection of flats to a drive (toothed) belt. An end head 36 of a flat 31 comprises an insert 41 and a glide surface 50. The insert 41 extends into the take-up portion of a hollow profile and is fixed therein. Fixation has been explained with reference to the Fig¬ures 8 through 11 in EP-A-627507 and thus repetition of the explanations here is dispensed with.
The glide surface is guided along the flexible arch 120 while the flat is in working position and along a rail (not shown) while it is on its return path. The glide surfa¬ce 50 is provided with two extensions 52 forming together a take-up opening 54.
The drive belt is designed as a toothed belt or power grip belt. The teeth on the Belt "inside surface" 56 (i.e. the surface facing the inside relative to the closed cir¬culation loop) engage the drive gears (not shown). On the "outside surface" 58 of the belt which faces the flexible arch 120 while the flats are in their working posi¬tion, recesses 60 are provided in pairs, each of which takes up an extension 52. Between the recesses 60 of each pair the belt is provided with a protrusion 10A forming an integral part of the belt. The protrusion 10A is taken up in the take-up opening 54 between the extensions 52. The protrusion 10A is provided with a
slot 11 and thus forms two "legs" each of which is provided in its foot portion with a cam 12. The extensions 52 each comprise an inclined surface 62 permitting better take-up and holding of the cams 12. The legs can elastically be pressed together in such manner that they form a snap-on connection with the end head 36 of the flat 31.
The connection established between the protrusion 10A and the extensions 52 on one hand is sufficiently strong to hold the flat on the belt (also if the latter no longer is guided by the arch 120) and to transmit the drive forces, and on the oth¬er hand can be released (manually) by an operator without using special tools. No additional (separate) elements being required manufacturing cost can be kept low and mounting and dismantling can be effected efficiently. The combina¬tion of materials in the glide surface of the flat and in the glide guide element of the arch can be adapted and optimised, whereas the flat body on which the card clothing is fixed still can be manufactured cost-efficiently and strength and weight of this element can be chosen optimally.
In designing the card flat described above advantageously steel or light metals such as aluminium are chosen. The flat 31 the profiled shape of which, shown in Fig. 3, is drawn if made from a steel tube, or is extruded via a suitably profiled template (so called extrusion moulding) if aluminium is used. If steel or alumini¬um are used, a cold forming processing is applied in manufacturing the flats. The end head 36 preferentially is made from cast iron or from sintered metal, but can also be made from any other solid metal. Care is to be taken, however, that the lower side of the end head is to be sufficiently hard as to resist undue and pre¬mature wear.
In Fig. 4 a first embodiment of the belt according to the present invention is shown, a short portion only of the elongated element being shown. The structur¬es shown, however repeat themselves in the longitudinal direction of the belt, and thus the description of the belt portion shown is sufficient for explaining the whole belt. The belt as whole is designated by the reference number 200 and comprises a continuous body 202 extending in the longitudinal direction, pairs
204, and 206 respectively, of connecting elements 208, and 210 respectively, and teeth 212. The Belt is cast in one piece into which longitudinally extending reinforcements (e.g. filaments or wires, not shown) can be incorporated during casting. The (matrix) material preferentially is an elastomer, e.g. polyurethane.
The body 202 is of predetermined width B (e.g. ranging from 20 to 30 mm) and of predetermined thickness D (e.g. ranging from 1 to 3 mm). The thickness D can be chosen in function of the tensile forces to be transmitted, e.g. in function of the number of flats. The length of the belt body 202 is explained in more detail in the following.
Each connecting element 208 and 210 respectively consists of a transverse rib extending across the whole width B of the body 202, i.e. at right angles with re¬spect to the longitudinal direction of the body. Each of the ribs 208 and 210 re¬spectively are of a predetermined height H (e.g. ranging from 3 to 8 mm). The rib 208, and 210 respectively, is tapered in its cross-section, the smaller "root" end of the taper neighbouring the body 202 and the wider head portion being arranged at the far end distant from the body 202. The ribs 208, and 210 respectively, of a pair (e.g. of the pair 204 shown also in Fig. 5) mutually represent mirror Images of each other, and between the ribs of the pair a distance A is provided which is constant over the whole height of the ribs while the belt extends straight (Fig. 5). in the embodiment shown this "slot" forming the distance extends down to the root of the ribs.
Each of the ribs thus forms an inclined surface 214 and 216 respectively, and the inclined surfaces of each pair are oriented in opposite directions. In the embodi¬ment shown each inclined surface of a pair (e.g. of the pair 204, Fig. 4) faces an inclined surface of the neighbouring pair (e.g. of the pair 206). The inclined sur¬face 214 and 216 respectively of a rib and the surface 220 of the body 202 neighbouring it enclose a predetermined angle a (e.g. ranging from 60 to 80 de¬grees) while the body 202 extends straight. As it will be explained in the follow¬ing each of the ribs 208 and 210 respectively show a rubber type elasticity at least in their root zones in such a manner that the ribs can be forced towards
each other by suitable forces as to reduce their mutual distance in the head por¬tion zone.
A belt body according to Figures 4 or 5 respectively is cut (or formed respective¬ly) to a predetermined length the end portions of the body being interconnected to form an endless loop belt for application in a revolving flat arrangement 5, 6 according to Fig, 1. Thus a revolving path is determined for the revolving flats connected to the belt for operation. On the opposite side the teeth 212 are ar¬ranged on the inside surface of the endless belt, and the pairs of ribs 204, 206 are arranged on the outside surface 220.
Let it be assumed first that the endless loop belt 200 moves in its own longitudi¬nal direction in such a manner that each pair of ribs 204,206 moves from the right hand side to the left hand side in the Figures 4 and 5. Preferably each pair of ribs is designed symmetrically and thus it actually it is not of importance in which direction it moves. Assumption of a certain direction, however, facilitates the following descriptions. In its "ready state" (the body 202 being extended straight without forces acting on the ribs 208, 210) the distance in longitudinal di¬rection of the body 202 between the preceding free edge K1 of the pair of ribs 204 (Fig. 5) and the subsequent free edge K2 of the same pair is of a predeter¬mined value "L" which can range from 12 to 25 mm. The distance "L" in the fol¬lowing will be called the "span" of the pair of ribs. The corresponding distance "I" at the root of the ribs 208, 210 in the same state is of a smaller predetermined value which can range from 9 to 22 mm.
A flat which is to co-operate with this belt is indicated in Fig. 6 with the reference number 222, and it comprises a hollow profile 224 and two end heads 226 one only of which is visible in Fig. 6 and Fig. 7 respectively. Each end head 226 is provided with a connecting part (not visible in these Figures, but compare the in¬sert 41 in Fig. 3) which is pressed into the corresponding end portion of the pro¬file 224 and held fixed therein. The preferred solution for fixing the end heads 226 in the profile 224 has been described in EP-A-627527 but any other fixation arrangement, which fulfils the requirements without complications, could be ap-
plied also. The Insert of the end head thus will not be described in more detail here. In any case at each end of the profile a glide shoe/clamp element 228 (Fig. 7) of the corresponding end head 226 protrudes from the end of the profile.
The element 228 comprises two mouldings 230 (Fig. 6) extending in the longitu¬dinal direction of the flat 222. These mouldings 230 each form a gliding surface 232 gliding on the gliding surface of the flexible arch while the flat is in its work¬ing position. The mouldings 230 are formed in one piece with traverses 234, iwhich together with the mouldings form an opening of predetermined size for tak¬ing up the corresponding elements of the belt 200. The size of this opening in the longitudinal direction of the mouldings 230 preferentially corresponds to the width B of the belt (or the length of the ribs respectively) (see Fig. 7 and Fig. 4). In :his manner it is ensured that the belts of the revolving flat arrangement and the lats of the arrangement center each other mutually laterally.
The clamp or connecting function respectively is achieved by two moulding parts 236 (Fig. 6) the cross-sections of which show a taper also in such a manner that hey each present an inclined surface 238, or 240 respectively. These inclined surfaces 238, 240 face each other and are separated by a predetermined mini-num distance Mn (Fig. 7) which is considerably smaller than the span L (Fig. 5) ind which is discussed in more detail in the following. The distances Mn and Mx espectively are called the "opening widths" of the clamping element.
n Fig. 8 a glide shoe/clamping element 228 is shown connected to a pair of ribs 207 of the belt 200. The clamping element has been snapped onto the pair of ibs in such a manner that the inclined surfaces 238,240 contact the inclined sur-aces 214,216 of the ribs. The height of each of the tapered portions of the nouldings 230 approximately equals the height H of the ribs 208, 210, but the to-al height LH (Fig. 6) of each moulding 230 is markedly higher, the gliding surfac-(S 232 (in the arrangement according to Fig. 8) thus being located high above he ribs 208, 210.
Each flat 222 is connected to a pair each of ribs in the same manner. The dis¬tance between neighbouring flats 222 is predetermined and is to be kept as small as possible; in Fig, 8 it is indicated with the reference sign "t". The distance t of course is determined by the design of the mouldings 230 and by the distance between neighbouring pairs of ribs. This later distance also is predetermined and at the roots of the ribs 208, 210 (neighbouring the surface 220 of the body 202) shows the value "S" (Fig. 8) ranging from 14 to 27 mm.
Any snap-on connection according to Fig. 8 is to generate holding forces to such an extent that the following minimum requirements are fulfilled:
- the gliding surfaces 232 are seated firmly on the gliding surfaces on the flexi¬ble arch (resistance against tilting momentum),
- in the working position, and during the reverse path passage respectively, the drive forces are reliably transmitted from the belt 200 to the flat 222,
- at the reversal points the flats 222 are reliably held on the belt 200.
The requirement mentioned last substantially determines the extent of the hold¬ing force required whereas the other two requirements mainly influence the de¬sign details of the transmitting elements. The holding forces generated at one snap-on connection are to take care of at least half the weight of the flat (without any noticeable weakening of the connection). The weight of a conventional flat ranges from 15 to 40 Newton. The holding forces connecting the flats to the belt are influenced on one hand by the the material (and particularly by its E-modu-lus) chosen for the fc>elt 200 and on the other hand by the "geometry" lay-out of the ribs 208, 210 and of the mouldings 230, in particular by:
- the length of the rib (equal to the width of the belt in the embodiment shown),
- the span of he pair of ribs in relation to the opening widths of the clamping el¬ement, and
- the value of the angle a enclosed by the Inclined surfaces.
The width Mn of the opening of the clamp element preferentially is chosen about equal to the dimension "I" (Fig. 5) at the roots of the ribs 208, 210. The maximum width Mx of the clamp, however, preferentially is chosen smaller than the span L of the pair of ribs. In the installed state (Fig. 8) the distance A of the ribs at their head portions thus is reduced somewhat, i.e. the mouldings 230 squeeze the ribs 208, 210 towards each other also in the fully snapped-on state. Much more force squeezing the ribs 208, 210 towards each other is required during the snap-on process, as will be explained in the following with reference to the Fig¬ures 10 through 12.
The holding forces furthermore are influenced also by the "degree of bending" of the belt body as explained with reference first to Fig. 9. The Figures 4, 5 and 8 all show (for the sake of simplicity) the belt body 200 extended straight. In reality the path of the revolving flats at no location extends straight, and in the end zones comprises a path section each in which the belt body undergoes considerable bending deflection. The outside surface of the body 202 with its ribs 208, 210 is bent convex. The influence of this bending deflection is shown in the absence of a clamping element in Fig. 9 - the ribs 208,210 of each pair are spread apart particularly at their head portions in such a manner that the distance A (Fig. 5) is increased to A+ (Fig. 9). Such an increase is not effected in the presence of a clamping element the mouldings 230 being strong enough to withstand the "el¬astic forces" exerted by the pair of ribs. These elastic forces, however effect a noticeable increase in the holding forces while a pair of ribs holding a flat passes around a deflecting roll 6 (Fig. 1). This increase in holding forces at the deflecting rolls is a very advantageous effect eliminating the need for special guide mech¬anisms for loose flats in the deflecting zone.
The snap-on connection according to the present invention must, however, also permit the release of a flat (e.g. for maintenance of the flats or for checking on a flat) as well as the re-installation of a flat - if possible while the revolving flat arr-
angement is (still) moving. Installation of a flat is shown schematically in Fig. 10. First, one of the inclined surfaces (214 in Fig. 10) of the corresponding rib (208 in Fig. 10) is brought into contact with the inclined surface (214 in Fig. 10) of the corresponding rib (208 in Fig. 10). In this arrangement the flat 222 is inclined in such a manner that the edge Ki on the other moulding of the clamp can contact the head portion of the other rib 210 (state shown in Fig. 10). As pressure is ap¬plied to the still free moulding, the rib 210 is deflected automatically in such a manner that the edge Ki can move past the edge K2 (Fig. 5) which effects the snap-on action of the clamp.
The simple shape of the rib head portion according to the Figures 4, 8 and 10 comprises a front surface extending in a single plane. If this shape is chosen, problems are to be expected during the "squeezing-in" process, and damages to the edges KI and K2 are likely to occur. A partial solution of this problem is indi¬cated in dashed lines In Fig. 5 where the front surface is bevelled, forming the guide surfaces 242, 244. Compared to the alternative design solution indicated with solid lines the span of the pair of ribs is reduced to LI. The transition zone between a guide surface and the corresponding inclined surface of the rib pref¬erentially is rounded off rather than forming an edge. This design precaution sim¬plifies the squeezing-on action according to Fig. 10. Installation as well as re¬lease of a flat under certain circumstances still could be somewhat tedious for the operator. This problem can be solved in an elegant way by reversing the effects according to Fig. 9. This solution is shown schematically in Fig. 11.
A bending deflection of the belt body 202 with its ribs 208, 210 on the concave surface of the belt brings the head portions closer together the distance A (Fig. 5) being reduced to "a" (Fig. 11) or even being annihilated. The span L or L1 is re¬duced correspondingly which facilitates the squeezing-on action. A minimum bending effect of this type is generated if a flat 222 is placed onto a gliding sur¬face of the flexible arch. The corresponding loosening of the holding forces on one hand is minimal and on the other hand occurs at a location which for in¬stalling, and taking off respectively, flats is unsuitable. These latter functions rather should be effected while the flats move through their reverse path 246.
There the belt 202 is supported preferentially by a reverse path guide rail 248 which can present a slight bend even in the "wrong" direction. Thus at least at one location (e.g. 250, Fig. 12) no guide mechanism should be provided for the belt in such a manner that here an operator can effect the desired deflection of the belt (with or without the use of tools) all by himself. This "fitting station" prefer¬entially is located in a zone where a belt portion in its movement along the re¬volving path leaves a deflecting roll and has not yet reached the reverse path guide rail. The fitting station also can be placed at another location along the re¬verse path, or even a plurality of fitting stations can be placed distributed along the path. In this arrangement it is important that the fitting stations on both belts mutually correspond.
In a preferred embodiment (Fig. 8) the inclined surface 238, and 240 respective¬ly, of each moulding 230 tightly hugs the inclined surface 214, and 216 respec¬tively, on the corresponding ribs 208, and 210 respectively,. In this manner it is achieved that the drive forces are transmitted from the belts onto the flats at a lo¬cation in the closest possible vicinity of the belt body 202. Owing to this arrange¬ment generation of tilting momentum acting on the flats can be prevented or at least be minimised.
In Fig. 13 a modification of the embodiment according to Fig. 12 is shown provid¬ed with a recess 252 in the reverse path guide rail 246 to which recess 252 a se¬curing plate 254 is co-ordinated. If now a pair of ribs (e.g. 207) with an incorrectly fitted flat approaches the plate 254 with its gliding head 228, the plate 254 press¬es the clamping element of the gliding head 228 down onto the pair of ribs. For this purpose the plate 254 is arranged rotatably supported on an axle 253 and is pre-tensioned by elastic means (e.g. the spring 256) towards the recess 252. The plate during normal operation maintains a predetermined distance from the re¬verse path guide rail owing to a stop which is not shown. As a clamping element snaps on, the plate is displaced upward (against the pre-tensioning action) by the reverse path guide rail 246.
The rail 246 in turn is supported rotatable about an axle 257 and is pre-tension-ed using elastic means 258 (e.g. a spring) in an upward direction for tensioning the belt 200. The belt thus during normal operation is not guided into the recess 252, but the recess is bridged by the belt. A deflection into the recess is effected under the pressure exerted by the plate 254 if the later is pressed upward as de¬scribed before. The deflection exerts the effect described above with reference to Fig. 11.
Both reverse path guide rails of course must be provided each (per machine side) with a device effecting mutual engagement of the elements of the snap-on connection. If the arrangement comprises a recess and a plate according to Fig. 13 the two devices must snap on the elements simultaneously.
The scope of the present invention is not limited to the embodiments shown. It is possible also e.g. to directly oppose the ribs and to provide the flats with a "snap-on lock" provided with two inclined surfaces which squeezes the ribs apart dur¬ing installation of the flat. An arrangement of this type, however, does not present the same resistance against torsion momentum which can be generated by the clothing during the carding action and which tends to tilt the flat about its own longitudinal axis.
Detectors can be provided for checking the flats engaged and their connections and generating an alarm signal if any defects are detected.
Each rib member can be formed by a plurality of a part rib members, each part extending only over part of the belt width.
The embodiment according to the present invention additionally provides the following advantageous effects:
1. The pre-tensioned connection of each flat to the belt dampens transmission of minor elongation deviations from the belts to the flat arrangement.
The positive connection between each flat to the belt evens out the longitudi¬nal forces in the belt, which results in a dampening effect on vibrations in the longitudinal direction.
Dampening of impacts affecting the flats during the carding action.
The spring characteristics of an elastomer material generate increasing resis¬tance against deforming forces as said forces increase.
1. A drive belt for the flats (222) of a revolving flat card in which the belt (200) is provided with connecting elements (208, 210) which are forming integral parts of a flexible belt (202) and are arranged in pairs in such a manner that a pair of elements (204, 206, 207) can be taken up in an element 226 of the flat, a snap-on connection being formed, characterised in that each element comprises a transverse rib (208, 210) provided with an inclined surface (214, 216), and in that the inclined surfaces (214, 216) of a pair of ribs (204, 206, 207) are oriented in mutually opposed longitudinal directions of the flexible belt (202), and in that, as the belt (202) is extended straight, the angle (a) enclosed between each inclined surface (214, 216) and the surface (220) of the belt (202) neighbouring it, ranges from 60 to 80 degrees.
2. The drive belt as claimed in claim 1, wherein the inclined surface (214, 216) extends from the belt (202) to the free front end side of the rib (208, 210).
3. The drive belt as claimed in claims 1 or 2, wherein the height (H) of the rib (208, 210), measured from the belt (202), ranges between 5 and 8 mm.
4. The drive belt as claimed in claims 1, 2 or 3, wherein the length of the rib (208, 210) corresponds to the width (B) of the belt (202).
5. The drive belt as claimed in claim 4, wherein the width (B) of the belt (202) ranges from 20 to 30 mm.
6. The drive belt as claimed in any one of claims 1 to 5, wherein between the ribs (208, 210) of a pair a distance (A) of at least 1 mm is provided at the level of their end portions.
7. The drive belt as claimed in claim 6, wherein the absence of a clamping force acting on the ribs the distance (A) increases if the belt (202) is bent, the ribs (208, 210) being located on the convex side of the belt (202).
8. The drive belt as claimed in claim 7, wherein the distance (A) is reduced if the belt (202) is bent, the ribs (208, 210) being located on the concave side of the belt (202).
9. The drive belt as claimed in claims 6, 7 or 8, wherein between the ribs (208, 210) of a pair (204, 206, 207) a distance (A) of at least 1 mm is provided at the level of the belt (202).
10. The drive belt as claimed in any one of the preceding claims, wherein the ribs (208, 210) of a pair (204, 206, 207) together form a symmetrical arrangement.
11. The drive belt as claimed in any one of the preceding claims, wherein between the ribs (208, 210) of neighbouring pairs a minimum distance (S) of 14 mm is provided at the level of the belt (202).
12. The drive belt as claimed in any one of the preceding claims, wherein the belt (202) is made as an endless belt.
13. A revolving flat unit, wherein a pair of drive belts is provided of which each of the belts (200) is made according to claim 12.
14. The revolving flat unit as claimed in claim 13, wherein at each flat (222) of the arrangement (5) is provided with a support element (224) for the card clothing, the support element (224) being provided with end heads (226) which are connected to a belt (200) each by means of a pair of ribs (204, 206, 207) each co-ordinated to the corresponding end head (226).
15. The revolving flat unit as claimed in claim 13, wherein each end head (226) is provided with two mouldings (230) each co-ordinated to a rib (208, 210) and which, together with the pair of ribs (204, 206, 207) form a snap-on connection between the flat (222) and the beh (200).
16. The revolving flat unit as claimed in claim 15, wherein the mouldings (230) are interconnected mutually at their ends distant from the support element (224).
17. The revolving flat unit as claimed in claims 15 or 16, wherein the mouldings (230) form an integral part together with a connecting insert (41) connected to the support element (224).
18. The revolving flat unit as claimed in claims 16 & 17, wherein the mouldings form an integral part together with a traverse member (234) interconnecting them at said ends.
19. The revolving flat unit as claimed in any one of the claims 14 to 18, wherein each support element (224) is designed as a hollow profile.
20. The revolving flat unit as claimed in any one of the claims 14 to 19, wherein each snap-on connection generates a holding force exceeding half of the weight of the flat (222).
21. The revolving flat unit as claimed in claim 20, wherein the weight of the flat (222) ranges between 15 N and 40 N.
22. The revolving flat unit as claimed in any one of the claims 13 to 21, wherein guides (120, 248) for the snap-on connection between the belts (200) and the flats (222) are provided.
23. The revolving flat unit as claimed in claim 22, wherein at least at one location (250) along the revolving flat path the guides (120, 248) for each belt (202) are formed in such a manner that the belt (202) can be bent with its pairs of ribs (204, 206, 207) on the concave side.
24. The revolving flat unit as claimed in claim 23, wherein said location (250) is placed on the reverse path (246) of the flats (222).
25. The revolving flat unit as claimed in claim 24, wherein at said location (250) a gap provided in the guide elements (120, 248).
26. A revolving flat unit as claimed in claims 24 or 25, wherein the location (250)
is placed at the beginning of the reverse path (246) of the flats (222).
27. A revolving flat unit as claimed in any one of the claims, wherein means (252,
254) are provided for pressing the elements of the snap-on connection into
28. A drive belt for the flats of a revolving flat card substantially as herein
described with reference to the accompanying drawings.
|Indian Patent Application Number||841/MAS/1996|
|PG Journal Number||20/2006|
|Date of Filing||20-May-1996|
|Name of Patentee||MASCHINENFABRIKE RIETER AG|
|Applicant Address||KLOSTERTRASSE 20 CH-8406 WINTERTHUR,|
|PCT International Classification Number||D01G015/08|
|PCT International Application Number||N/A|
|PCT International Filing date|