Title of Invention

INTEGRAL CAM OPERATED ROTARY SWITCH

Abstract

The invention in general relates to an intergral cam operated rotary switch having plurality of switching contacts, switching positions, switching angels in which the detent function is integral with the contact operating cam function. The noverlty of this invention is to provide specific cam and spring combinstion in which the contact spring design ansures minimum force while closing and optimum sufficient force while opening. In this detant function, an intergral part cam shaft which housand inside the housing of the switching moduls enables the fixed metallic contacts located on both sides of the housing for malding and breelding the circuit. The moving contact located in the contact slide acts as a follower for the cam wheel which moves to and fro with respect to cam shafts poriles. This contact slide located by the contact spring provides sufficient force for opening and closing the contacts. There are terminal screws and terminal clamp for tightening the incoming and outgoing wires in the circuit. The cam shaft meens in provided with a switch operated by handle/knob for rotation into verious angular positions corresponding to the required settings. There is a mounting plats which used for fixing the swich in the switchboard and front plate used for fixing the script plates by meens of script plats ring and whole front plates assembly is fixed to the switchboard by means of fixing screw. There is a gasolost provided in the swith to prevent the entry of dust or water particles in to the switching module. In this mechanism when the switch is rotated, the cam wheels rotate thereby pushing the spring loaded followers and stores the energy for half of the rotation of the switching angles and if it is rotated beyond half of the switching angle, the spring ressless the anargy thereby pushing the cam and the switch shaft to the next detant position. Thus this rotary switch is made very compact and cost affective.

Full Text

SCOPE This invention relates to the rotary switches and more particular to Integral cam operated rotary switch wherein the circuits are activated in one or more switch positions (settings) and wherein a programmed activation of said load circuits are provided. PMQRART ;- In this specification, when referring to electrical terms such as electrical current, electrical circuit, electrical conductor etc. the words 'electric' and 'electrical' have been dropped in the interest of conciseness. A switch is an electromechanical component which control a circuit in its simplest form, a switch has two operational position in one of which a circuit is made (or closed) and in the other it is brol A simple circuit comprises a source (of electrical energy) and a load and conductors extending from source of load and back such as to complete a circuit round which a current could flow. The load may be any device or component that uses electrical energy. The source may be a single phase or three phase supply with or without neutral. In certain cases it may be an output of a current transformer or voltage transformer. The switch is interposed in a circuit either on the conductor outgoing from the source or on the conductor incoming to the source or on the both. As mentioned herein above, a simple switch has a pole and a load terminal. It further has contact(s) made out of metallic contacts which upon closing of the switch provide continuity for the current to flow fi'om pole to load terminal. A contact comprises a pair of contact elements (surface) which upon operation of the switch establish electrical contact with each other. A double contact comprises two pairs of contact elements (surface) which, the switch is operated come simultaneously into electrical contact with each other. Double contacts in switches can be in series or In parallel, the former being more common In double butt contacts. This point is further elaborated herein below. A contact, as mentioned, comprises two contact elements (surface) which establish electrical contacts such as to close a circuit. Commonly one of the contact element is stationary which the other moves towards it to establish contact of the surface. The movement of the moving element may be sideways with respect to the contact surface or frontal. In case of the former, two contact surfaces slide over each other before coming to restfully abutting each other. Such contacts are called wiping contacts because of certain amount of mutual wiping of the contact surfaces takes place during said movement. In the case of the later, the moving contact ajrftice moves frontally till it comes to rest abutting the stationary contact surface. In this case, no wiping action occurs. This type of contact is called a butt contact Both double wiping type and double butt type contacts are found In the art. A simple rotary switch comprises pole and a set of load terminals wherein contact between pole and load terminals is provided by a moving member which is In contact with the pole and which, as it moves, successively makes contact with the load terminals. Modern rotary switches are, however, more complex and standardized. The selective switching action between pole(s) and load terminates) in a rotary switch is now carried out in a unit, which is called a switching module. Switching modules are standardized and a rotary switch may comprise one or more of switching modules. Switching modules are also referred to in the art as decks, packets and stages and by other terms but in this specification the term ^switching modules' is uniformly used. A switching module essentially comprises a shaft the rotation whereof causes selective switching action to take place in tin% module. At one end of shaft Is mounted selection means such as knob or handle or others by means of which shaft Is rotated selection means such as knob or handle or others by means of which shaft is rotated and placed into various angular positions corresponding to settings of the rotary switch. Detent means provide firm location of the shaft in its various angular positions, Adjacent selector means a faceplate is located on the shaft. The shaft has makings thereon indicating the ettings of the switch and also pictorial and/or written information about settings, the load(s) energized In each setting and other information. The shaft is mounted on the faceplate and the faceplate is provided with screw means or other fixing means for mounting upon a switchboard or control panel. Thus the rotary switch. In this case, is mounted on a panel, switchboard through the means of the faceplate. In other cases, particularly where the rotary switd-i to be mounted is somewhat bulky shaft is provided with means to mount it on panel/switch board. In yet other cases, the, the mounting means are provided on the body of the rotary switch for mounting the same on panel/switchboard. In the last two mentioned types of mounting arrangements the faceplate becomes redundant and the information thereon Is provided on the panel/switchboard itself. As regards mounting of rotary switches, front mounting, rear mounting and split mountings are practiced. The difference between these is marginal and the switches of the invention are equally adaptable to all these application. Optionally, there Is a faceplate, which sometimes also serves the function of said mounting means. Generally speaking, rotary switches adapted for multl circuit operation have a plurality of switching modules. In fact, the number of switching modules required depend upon either the total number of toads to be energized or the maximum number of loads to be simultaneously energized depending on the type of switching modules to be used. Switching modules are of two types : 1. rotary arm type ; and 2. cam type. Rotary switches are also referred to as rotary arm type or cam type depending on the type of switching modules incorporated in them. In rotary arm type switching modules, said selective switching action Is performed by an arm which is mounted on said shaft and rotates therewith. In an Integral cam type switching modules, said switching action Is done by means of cam wheel(s) / dlsc(s) mounted on said shaft and rotatable therein. With regard to rotary arm type rotary switches it will be observed that if a particular load forms part of say three load combinations then that load will have three load terminals one each In each of the three load terminal arrays associated with these combinations. It Is necessary then to Interconnect these three load terminals with the help of specially designed Jumpers. A jumper for the purpose of this specification Is understood to mean as substantially rigid metallic component such as of pressed copper strip or copper wire fix able between two or more load terminals to provide interconnection there between. Consider a typical application where a rotary switch supplies power to a set load terminals in a programmed manner. This applies to both rotary arm type and cam type rotary switches. If a load, say appears In three load combinations then In case of the rotary arm type units there would have to be Interconnected by jumpers. In contrast, in a cam type rotary switch only one load terminal is associated with each load and so the necessity for Interconnecting load terminals with jumpers does not at all arise In cam type units. ADVANTAGES OF CAM TYPE ROTARY SWITCH :- Cam type rotary switches have clear and significant advantages over rotary arm type units. Cam type units are more compact, lighter and more economical over rotary arm type units. In addition cam type units have overwhelming operational advantages over the rotary arm type units. These are;- i. cam type rotary switches can be used for inductive loads unlike the rotary arm type units ; and ii, the double butt contacts of cam type units offier far smoother operation of the switch involving less effort. Therefore, there is provided a cam type rotary switch having a plurality of switch settings, a plurality of circuits being activatable In one or more of settings, comprising : a. a shaft means comprising one or more shafts and provided with a handle, knob or the like means of rotation thereof lr\to various angular positions corresponding to the settings ; b. a separate detent comprising a cam component mounted on the shaft and rotatable therewith, and spring means such as to provide firm location of the shaft in the determined angular positions ; c. one or more switching modules located along the shaft, each comprising sets of poles and load terminals, one or more cam wheels, mounted on the shaft and rotatable therewith and a set of spring loaded double butt contacts, contacts being activatable by cum wheels upon rotation thereof such as to provide programmed interconnections between sets of poles and load terminals; and d. one or more jumpers interconnecting poles and/or toad terminal such as to provide programmed operation of rotary switch. There are flexibilities in the design of cam operated rotary switches such as: Selector means : This selector means may be a handle or knob several designs of which are known in the art. Some of the designs provide facility for locking knob or handle. Face plate : This component indicates the positions of the various settings and may further have information, pictorial or otherwise of the load energised at different settings. The information provided on the face plate is sometimes indicated on the control panel/switchboard on which the rotary switch Is mounted. In that case the face plate can be dispensed with. In the embodiment described in detail herein below, the face plate also performs the function of mounting. The rotary switch is mounted on the face plate which, in turn, is mounted upon a panel/switchboard by means of screw/snap hooks Is designed to fit various standardized switchboards marketed by various companies. The face plate has been given suitable/treatment to provide good visibility and is provided with an LED which indicates whether the power is on. Mountings : For medium and large sized rotary switches it is rather not feasible to mount them on face plates. Medium sized units often have screws provided on the shaft of the selector and the detent assembly such that the shaft (and the switch) is mounted in a suitable sized hole provided in the control panel or switchboard. Larger sized units are provided with brackets, and if necessary tie rods, for mounting directly onto the panels/switchboards. Mounting arrangements are varied. Some units are mounted on the front panel/board of the control panel/switchboard and others on the rear panel/board thereof. Some units have split mounting that is, part of the unit is mounted at front and part at the rear. Detent : The switches of the invention may incorporate any of the different designs of the detent available in the art A typical design comprises a substantially cylindrical box the inside circular surface of which is contoured to correspond with the switch settings, that is, having valleys and ridges at corresponding angular distances. An elongated member having cam like ends rotates with the switch shaft the cam like ends being spring loaded. As the cam like ends follow said contours they move to and fro radially causing the spring to alternatively absorb and release energy. During the phase in which the springs release energy they urge the elongated member and the switch shaft to move precisely into the adjacent setting position. Instead of the elongated member in the embodiment described in detail herein below, there is a cam wheel having several cam like ends located on the circumference thereof. The detent also have stop for stopping the rotation of the shaft at a desired point. This is useful where the settings of the switch do not extend the full 360 degrees of a circle and it is necessary to put a limiting stop to the movement of the selector. Shaft : The shaft may comprise of a single shaft extending from the selector knob to the last of the switching modules. Alternatively, In accordance with this invention the shaft may comprise segmental shafts one for the knob and detent assembly and one each of for each of the switching modules. Single shafts of rotary switches are often of metal particularly If the switch has a large number of modules. However, as segmental shafts are of smaller lengths plastics can be conveniently used. Sattings ; In the embodiment described in detail, the rotary switch has been provided with different angular settings. The lowest practical value of angle in the art is considered to be 15 degree giving a maximum of 24 settings Including the OFF position. OBJECT OF THE INVENTION :- As mentioned herein above, this invention has developed Integrated cam operated rotary switches for programmed operations. In view of the overwhelming design, operational and economic advantages In favour of cam type rotary switches this invention has carried further the development of the cam type rotary switch to the stage of full fledged commercial prototype incorporating other features known In the art and desired by the users. This embodiment is the one described in detail further herein below. DESCRIPTION OF THE INVENTION :- The object of this invention is to provide en Integral cam operated rotary switch whereas the detent means are Integral with the cam wheel for the switching of the circuits in the switching modules. The housing of the switching module and the Top cover which covers the housing are fastened together. The Cam shaft is the integral part of the detent which Is located and housed In the housing for enabling the contacts to open and close the circuit along with the detent, The Fixed contact is a stationary metallic component which is rivetted by a Silver cladded button which is located in the housing on both the sides of the housing for making and breaking the circuit when the moving contact moves to and fro with respect to the cam shaft's profile which are pre determined for the switching sequence. The moving contact is located in the Contact slide which acts as a follower for the cam wheel and the contact slide is loaded by the Contact spring to have sufficient force for opening and closing the contacts and for detent function which happens simultaneously. The Terminal screws and Terminal clamp are used for tightening the incoming and outgoing wires in the circuit. The Mounting plate is an integral part of the housing for fixing the switch in the panel/switchboard. The Front plate Is used for fixing the Script plate and the script plate Is locked by means of the Script plate ring and whole Front plate assembly is fixed to the panel/switchboard by means of the Mounting plate fixing screw in the Mounting plate. The switch is operated by the Knob/handle which is tightened by means of Knob screw to the Knob shaft. A Gasket provided In the switch which Is sandwiched between the panel/switchboard and the mounting plate to ensure no dust or water particles are entered to the switching module from the access of front plate. The detent portion of the cam wheel is made in such a way that it stores and releases the energy keeping the contact in open position. The curvature is developed for the required torque of operating the switch. The curvature Is different for the detent function. The total cam lift is more for the cam operation function. As the switch operating mechanism is rotated, the cam wheels rotate thereby pushing the spring loaded followers away from the axis of the switch. This stores the energy for half of the rotation of the switching angle. The switching angle is defined as the angle between the two adjacent detent positions. As the operating mechanism is rotated beyond half of the switching angle, the spring releases the energy thereby pushing the cam and the switch shaft to the next detent position. This arrangement Is made for each of the switching contact which shall be switched in their respective switching angles. The various cams, equal in number to the number of contacts are integral made of single material. The orientation between the cam portion on the central shaft depends on the switching sequence requirement. Depending on the requirement this integral cam may have a stopping arrangement with the body of the switch. NOVELTY 5 The novelty of this Integral cam operated rotary switch is the special cam and spring combination which by itself detents. The contact spring is of a special design ensuring minimum force while closing and optimum sufficient force while opening to act as a detent spring. Thereby the switch Is made compact and cost effective. ILLUSTRATION ; In order to provide a clearer understanding of the invention, the invented design is described in detail herein below by way of example and without limitation to the scope of the invention, by reference to the accompanying drawings wherein : Fig.l is a cross-sectional view of the assembled switch of the invention. Fig.2 depicts the Face Plate. Fig.3 shows a sectional view of the switch, Reference number 1 in the figures denotes the housing of the switching module and the Top cover 2 which covers the housing and fastened together. The Cam shaft 3 is the integral part of the detent which is located and housed In the housing for enabling the contacts to open and close the circuit along with the detent. The Fixed contact 4 is a stationary metallic component which is rivetted by a Silver cladded button which is located in the housing on both the sides of the housing for making and breaking the circuit when the moving contact 5 moves to and fro with respect to the cam shaft's profile which are pre determined for the switching sequence. The moving contact is located in the Contact slide 8 which acts as a follower for the cam wheel and the contact slide is loaded by the Contact spring 9 to have sufficient force for opening and closing the contacts and for detent function which happens simultaneously. The Terminal screws 7 and Terminal clamp 6 are used for tightening the incoming and outgoing wires in the circuit. The Mounting plate 16 is an integral part of the housing for fixing the switch in the panel/switchboard. The Front plate 15 is used for Axing the Script plate 10 and the script plate is locked by means of the Script plate ring 14 and whole Front plate assembly Is fixed to the panel/switchboard by means of the Mounting plate fixing screw 12 in the Mounting plate. The switch is operated by the Knob/handle 11 which is tightened by means of Knob screw 17 to the Knob shaft 13. A Gasket 18 provided In the switch which is sandwiched between the panel/switchboard and the mounting plate to ensure no dust or water particles are entered to the switching module from the access of front plate. The detent portion of the cam wheel is made in such a way that it stores and releases the energy keeping the contact in open position. The curvature Is developed for the required torque of operating the switch. The curvature is different for the detent function. The total cam lift is more for the cam operation function. As the switch operating mechanism Is rotated, the cam wheels rotate thereby pushing the spring loaded followers away from the axis of the switch. This stores the energy for half of the rotation of the switching angle, The switching angle is defined as the angle between the two adjacent detent positions. As the operating mechanism Is rotated beyond half of the switching angle, the spring releases the energy thereby pushing the cam and the switch shaft to the next detent position. This arrangement is made for each of the switching contact which shall be switched In their respective switching angles. The various cams, equal in number to the number of contacts are integral made of single material. The orientation between the cam portion on the central shaft depends on the switching sequence requirement. Depending on the requirement this integral cam may have a stopping arrangement with the body of the switch. An Integral cam operated rotary switch having plurality of switching contacts, switching positions, switching angles in which the detent function is integral with the contact operating cam function comprising: a housing of the switching module and top cover 2 which covers the housing and fastened together, the Cam shaft 3 is the integral part of the detent which Is located and housed In the housing for enabling the contacts to open and close the circuit along with the detent, the Fixed contact 4 is a stationary metallic component which is rivetted by a Silver cladded button which is located in the housing on both the sides of the housing for making and breaking the circuit when the moving contact 5 moves to and For with respect to the cam shaft's profile which are pre determined for the switching sequence, the moving contact is located in the Contact slide 8 which acts as a follower for the cam wheel and the contact slide is loaded by the Contact spring 9 to have sufficient force for opening and closing the contacts and for detent function which happens simultaneously, the Terminal screws 7 and Terminal clamp 6 are used for tightening the incoming and outgoing wires in the circuit, the Mounting plate 16 is an integral part of the housing for fixing the switch in the panel/switchboard, the Front plate 15 is used for fixing the Script plate 10 and the script plate is locked by means of the Script plate ring 14 and whole Front plate assembly is fixed to the panel/switchboard by means of the Mounting plate fixing screw 12 In the Mounting plate, the switch is operated by the Knob/handle 11 which Is tightened by means of Knob screw 17 to the Knob shaft 13, a Gasket 18 provided in the switch which is sandwiched between the panel/switchboard and the mounting plate to ensure no dust or water particles are entered to the switching module from the access of front plate. the detent portion of the cam wheel is made in such a way that It stores and releases the energy keeping the contact In open position, the curvature is developed for the required torque of operating the switch, the curvature Is different for the detent function, the total cam lift is more for the cam operation function, as the switch operating mechanism is rotated, the cam wheels rotate thereby pushing the spring loaded followers away from the axis of the switch, this stores the energy for half of the rotation of the switching angle, the switching angle is defined as the angle between the two adjacent detent positions, as the operating mechanism is rotated beyond half of the switching angle, the spring releases the energy thereby pushing the cam and the switch shaft to the next detent position, this arrangement is made for each of the switching contact which shall be switched in their respective switching angles, the various cams, equal In number to the number of contacts are integral made of single material, the orientation between the cam portion on the central shaft depends on the switching sequence requirement, depending on the requirement this integral cam may have a stopping arrangement with the body of the switch. An integral cam rotary switch wherein the shaft means Is provided with a handle or knob on the like means for rotation into various angular positions corresponding to the required settings. An integral cam rotary switch wherein the switch contact housings into two or more parts which are fastened together by snap fit or fasteners which the cams, contacts, followers and springs and provides for termination of incoming and outgoing conductors in which the common poles are integrated with single termination. An integral cam rotary switch wherein a panel mounting arrangement with or without switching positions marked on the same. WE CLAIM : 1. An integral cam operated rotary switch having plurality of switching contacts, switching positions, switching angles In which the detent function is integral with the contact operating cam function comprising: a housing with a top cover, fixed set of switching contacts on two sides and within the housing, a switch shaft extending from a selector knob of a switch operating mechanism, plurality of cam wheels each with plurality of contours of cam like ends located on the circumference of the switch shaft and rotatable therewith, a contact slide (8) follower for each cam, a moving contact surface fitted onto the contact slide and a contact spring loaded on to the contact slide so as to open and close the contacts with force alongwith detent function, such that as the cam like ends of the cam wheel moves to and fro radially causes the contact spring to alternatively absorb and release energy, such that when switch operating rotates the cam wheel rotates, pushes the spring loaded contact slide followers away from the axis of the switch and spring storing energy until half of rotation of switching angle. such when switch operating mechanism is rotated beyond half of switching angle the spring releases the energy and thereby pushing the cam wheel and switch shaft to next detent position, wherein the number of cams is equal to number of contacts which are switched in respective switching angles i.e., number of switching modules, wherein the detent portion of cam wheel Is such as to store and release energy keeping the contact in open position. 2. An integral cam rotary switch as claimed In claimed, substantially described in the complete specification and illustrated in the drawings.

Documents:

862-mas-1999 abstract duplicate.pdf

862-mas-1999 claims duplicate.pdf

862-mas-1999 claims.pdf

862-mas-1999 correspondence others.pdf

862-mas-1999 correspondence po.pdf

862-mas-1999 description (complete) duplicate.pdf

862-mas-1999 description (complete).pdf

862-mas-1999 drawings duplicate.pdf

862-mas-1999 drawings.pdf

862-mas-1999 form-1.pdf

862-mas-1999 form-19.pdf

862-mas-1999 form-26.pdf

862-mas-1999 form-5.pdf