CLIAMS:1. A rotary switch comprising:
a switch handle;
a rotary mechanism operatively coupled to the switch handle and configured to control actuation of the switch handle between a first position and a second position, wherein the first and second positions correspond to ‘ON’ and ‘OFF’ conditions of the switch; and
a contact system operatively coupled to the rotary mechanism and to the switch handle, wherein the contact system is configured with contact paths and a means to make or break the contact paths in a synchronized manner as the switch handle is moved between the first and second positions, and wherein the contact system incorporates more than two contact paths in a single stage.
2. The rotary switch of claim1, wherein the rotary mechanism comprises a star shaped cam and a mechanism stopper configured to move the switch between the first position and the second position.
3. The rotary switch of claim1, wherein the rotary mechanism further comprises two stopper pins and a pin that are configured to restrict movement of the rotary mechanism within a predetermined range.
4. The rotary switch of claim1, wherein the contact system comprises a bottom housing configured to house terminals and bridge assemblies for the contact paths.
5. The rotary switch of claim 4, wherein the bridge assemblies incorporate a moving contact configured to make or break the contact paths.
6. The rotary switch of claim 4, wherein the bottom housing incorporates slots, wherein the bridge assemblies are operatively coupled to the slots for sliding motion in one direction.
7. The rotary switch of claim 4, wherein the contact system further incorporates a cam that is operatively coupled to the rotary mechanism and to the switch handle such that when the switch handle is moved between the first position and the second position, the cam also moves between the first position and the second position.
8. The rotary switch of claim 7, wherein the bridge assemblies are operatively coupled to the cam such that the cam, when moved between the first position and the second position, causes the bridge assemblies to slide and make or break the contact paths.
9. The rotary switch of claim 4, wherein the bottom housing incorporates clearances and creepages to prevent internal arcing and flashover.
10. The rotary switch of claim 4, wherein the bottom housing further incorporates venting near terminals for escape of generated gases.
,TagSPECI:TECHNICAL FIELD
[0001] The present disclosure generally relates to the field of low voltage power control equipment. In particular it relates to a rotary cam switch carrying multiple contact points in a single stage.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art
[0003] Low voltage power supply and control systems require switching equipment that provide isolation and are capable of making, carrying and breaking currents under normal conditions. These switches should also be capable of withstanding short circuit conditions for 1 sec. within the power distribution and control systems these switches are required for diverse applications such as in motor control centers, in switchboards and panels for switching of equipment and machines and switching of main / control and instrumentation circuits, motor ON-OFF and other special application circuits.
[0004] In three phase applications, the control switches are required to control all phases simultaneously which is typically achieved by arranging individual switches pertaining to different phases at different depths (multiple stages). This arrangement leads to requirement of considerable depth in panels where these switches are installed which may not be available in certain applications.
[0005] There is therefore need for a switch that accommodates multiple contact points (more than two) in a single stage thereby reducing the depth of the switch and corresponding reduction in requirement of space in switch panel. Such a switch can result in overall economy in manufacture and in installation with corresponding benefit to users.
[0006] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0007] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0008] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0009] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0010] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims.

OBJECTS OF THE INVENTION
[0011] An object of the present disclosure is to provide a rotary switch capable of making, carrying and breaking current in a low voltage circuit.
[0012] Another object of the present disclosure is to provide a rotary switch with multiple contact paths in a single stage.
[0013] Another object of the present disclosure is to provide a rotary switch capable of withstanding short circuit conditions up to 1 second.
[0014] Another object of the present disclosure is to provide a rotary switch capable of diverse applications.
[0015] Another object of the present disclosure is to provide a rotary switch design that prevents internal arcing and flashover.
[0016] Another object of the present disclosure is to provide a rotary switch that has adequate venting.
[0017] Another object of the present disclosure is to provide a rotary switch that has reduced depth thus overcoming the problem of installing switches in panels which have lesser depths for mounting.

SUMMARY
[0018] Aspects of present disclosure relate to a rotary cam switch carrying multiple contact points in a single stage. In an aspect the disclosed switch incorporates more than two contact points in a single stage and thus can be used for three phase applications without need for extra depth in panel.
[0019] In an embodiment the disclosed switch can comprise of a rotary mechanism and a contact system. The rotary mechanism can be configured to control the actuation of a switch handle between two desired positions and accordingly actuate the contact system operatively coupled to the rotary mechanism. The contact system can be configured with multiple contact paths and means to make or break these contact paths in a synchronized manner as the switch handle is moved from one desired position to other.
[0020] In an embodiment, the rotary mechanism can be cam based. It can comprise a star shaped cam and a mechanism stopper. The star shaped cam and the mechanism stopper are configured to move the switch between two desired positions corresponding to ON and OFF conditions. The rotary mechanism can further comprise two stopper pins and a pin. The two stopper pins and the pin together can be configured to restrict the movement of rotary mechanism within a desired predetermined range such as 60 degree.
[0021] In an embodiment, the contact system can also be cam based and can comprise a bottom housing and a cam. The bottom housing can be configured to house terminals and bridge assemblies for multiple contact paths. Each of the bridge assemblies can incorporate a moving contact configured to make or break the contact path. Further each of the bridge assemblies is operatively coupled to a slot in the bottom housing and configured for sliding motion in one direction. The bridge assemblies are also operatively coupled to the cam; the cam when rotated from one desired position to other causes the bridge assemblies to slide and make or break the contact paths.
[0022] In an embodiment the bottom housing can accommodate three different contact paths thus eliminating requirement of additional stage. The bottom housing also incorporates required clearances and creepages so that no internal arcing or flashover can take place. Further the bottom housing also incorporates proper venting near terminals from where the generated gases can escape out.
[0023] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components

BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0025] FIG. 1 illustrates an exemplary schematic view of the rotary cam switch in accordance with embodiments of the present disclosure.
[0026] FIG. 2A and FIG. 2B illustrate exemplary top view and side view of the rotary cam switch in accordance with embodiments of the present disclosure.
[0027] FIG. 3 illustrates an exemplary exploded view of the rotary cam switch in accordance with embodiments of the present disclosure.
[0028] FIG. 4 illustrates an exemplary schematic view of the contact system in accordance with embodiments of the present disclosure.
[0029] FIG. 5A, FIG. 5B,FIG. 5C and FIG. 5D illustrate exemplary schematic diagrams of terminal assembly, bridge assembly, cam and bottom housing respectively of the contact system in accordance with embodiments of the present disclosure.
[0030] FIG. 6A, FIG. 6BandFIG. 6Cillustrate exemplary schematic views of the contact system during operation from OFF to ON position in accordance with embodiments of the present disclosure.
[0031] FIG. 7A, FIG. 7BandFIG. 7C illustrate exemplary schematic diagrams of the rotary mechanism indicating working of two stopper pins and a pin to restrict the movement of the switch to 60 degree in accordance with embodiments of the present disclosure.
[0032] FIG.8 illustrates an exemplary schematic diagram of the rotary mechanism with star shaped cam and mechanism stopper in accordance with embodiments of the present disclosure.
[0033] FIG. 9A, FIG. 9B and FIG. 9C illustrate exemplary schematic diagrams indicating working of a star shaped cam and mechanism stopper in accordance with embodiments of the present disclosure.
DETAILED DESCRIPTION
[0034] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0035] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0036] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0037] Embodiments of the present disclosure relate to a rotary cam switch carrying multiple contact points in a single stage. In an aspect the disclosed switch incorporates more than two contact points in a single stage and thus can be used for three phase applications without need for extra depth in panel.
[0038] In an embodiment the disclosed switch can comprise of a rotary mechanism and a contact system. The rotary mechanism can be configured to control the actuation of a switch handle between two desired positions and accordingly actuate the contact system operatively coupled to the rotary mechanism. The contact system can be configured with multiple contact paths and means to make or break these contact paths in a synchronized manner as the switch handle is moved from one desired position to other.
[0039] In an embodiment, the rotary mechanism can be cam based. It can comprise a star shaped cam and a mechanism stopper. The star shaped cam and the mechanism stopper are configured to move the switch between two desired positions corresponding to ON and OFF conditions. The rotary mechanism can further comprise two stopper pins and a pin. The two stopper pins and the pin together can be configured to restrict the movement of rotary mechanism within a predetermined range such as 60 degree.
[0040] In an embodiment, the contact system can also be cam based and can comprise a bottom housing and a cam. The bottom housing can be configured to house terminals and bridge assemblies for multiple contact paths. Each of the bridge assemblies can incorporate a moving contact configured to make or break the contact path. Further each of the bridge assemblies is configured for sliding motion in one direction by being operatively coupled to a slot in the bottom housing. The bridge assemblies are also operatively coupled to the cam; the cam when rotated from one position to other causes the bridge assemblies to slide and make or break the contact paths. The cam can be configured in a manner to cause synchronized making and breaking of all the contact points together.
[0041] In an embodiment the bottom housing can accommodate three different contact paths thus eliminating requirement of additional stage for three phase application. The bottom housing also incorporates required clearances and creepages so that no internal arcing or flashover can take place. Further the bottom housing also disclosure incorporates proper venting near terminals from where the generated gases can escape out.
[0042] Referring now to FIG. 1, an exemplary schematic view of the rotary cam switch 100 is disclosed in accordance with embodiments of the present disclosure. The disclosed rotary cam switch 100 (also referred to as switch 100 and two terms used interchangeably hereinafter) can comprise of a rotary mechanism 102 and a contact system 104. The rotary mechanism 102 can be configured to control the actuation of a switch handle 106 between two desired positions such as ‘ON’ position and ‘OFF’ position marked on top plate 108. The switch handle 106, the rotary mechanism 102 and the contact system 104 can be operatively coupled through a shaft (not shown here) such that when switch handle 106 is operated from one position to the other position, the rotary mechanism 102 actuates the contact system 104. The contact system 104 can be configured with multiple contact paths and means to make or break these contact paths in a synchronized manner as the switch handle is moved from one position to other.
[0043] FIG. 2A illustrates an exemplary top view 200 of the rotary cam switch 100 in accordance with embodiments of the present disclosure. The view shows the switch handle 106 and the top plate 108. The top plate 108 can be marked with ‘ON’ and ‘OFF’ positions and these markings can correspond to positions that the switch handle 106 can take under control of the rotary mechanism 102.
[0044] FIG. 2B illustrates an exemplary side view 250 of the rotary cam switch 100 in accordance with embodiments of the present disclosure. Shown in the view 250 are the rotary mechanism 102 and the contact system 104 coupled to each other by means of plurality of spacers 176 placed along the outer edge of the rotary mechanism 102 and the contact system 104. The rotary mechanism 102 and the contact system 104 can be further operatively coupled to each other by the shaft 178 that can additionally hold the switch handle 106 such that when the switch handle 106 is moved from one position to other, shaft 178 moves the rotary mechanism 102 and the contact system 104 in synchronization with the rotary mechanism 102 controlling the movement. The view 250 also shows the stopper pin 182 (only one out of two are shown in the view250) and the pin 180 that are configured to restrict the movement of the switch 100 within a predetermined range and in the exemplary embodiment the movement is restricted to 60 degree.
[0045] FIG. 3 illustrates an exemplary exploded view 300 of the rotary cam switch100 in accordance with embodiments of the present disclosure. Shown therein are the rotary mechanism 102, the contact system 104, the switch handle 106,the top plate 108, the spacers 176, the shaft 178, the stopper pin 182 and the pin 180. Also shown are rivets 302 that can hold the rotary mechanism 102, the contact system 104, the spacers 176 and the top plate 108 together.
[0046] FIG. 4 illustrates an exemplary schematic view 400 of the contact system 104 in accordance with embodiments of the present disclosure. The contact system 104 can comprise of a bottom housing 402 and a top housing 404. The bottom housing 402 can be configured to house multiple bridge assemblies 406 such that these can move only in radial direction. The exemplary embodiment is configured with three bridge assemblies 406 corresponding to three contact paths such that the switch 100 can be used for three phase application. As is apparent, if the bottom housing 402 were to house less than three contact paths one more housing in an additional layer corresponding to an additional stage would be required to accommodate additional contact path for the third phase thereby increasing the height of the switch 100 with corresponding increase in space requirement.
[0047] Though the exemplary embodiment shows only three contact paths, it would be apparent to those skilled in art that it is possible to add more paths in the bottom housing 402 with corresponding changes in other parts of the switch 100 and all such modifications are within the scope of the present disclosure.
[0048] In an embodiment, the bridge assemblies 406 can be backed by springs410 to move the bridge assemblies 406 towards center of the bottom housing 402. Each of the bridge assemblies 406 can comprise a moving contact 408 that can move along with bridge assembly 406 and make contact with terminal assemblies 412 configured on the bottom housing 402 as shown. Thus movement of the bridge assembly 406 towards center of the bottom housing 402 can make the contact of the corresponding contact path and its movement away can break the contact path.
[0049] In an embodiment, the bottom housing 402 can further comprise a cam 414 that can be configured in the center of the bottom housing 402 and rotate relative to the bottom housing 402. It can be further configured to cause movement of the bridge assemblies 406 in a synchronized manner so that all the contact paths are made or broken simultaneously. It should be understood that though in the exemplary embodiment all contact points make or break simultaneously in synchronized manner, it is possible to configure the cam 414 differently such that the multiple contact paths are made or broken in any set pattern to meet the requirement of different applications and all such modifications are within the scope of the present disclosure.
[0050] In an embodiment the bottom housing 402 incorporates required clearances and creepages so that no internal arcing or flashover can take place. Further the bottom housing 402 also incorporates proper venting near terminals as illustrated in ‘detail A’ showing arcing place 416 (between the moving contact 408 and terminal assembly 412) and passage for venting 418 from where the generated gases can escape out.
[0051] FIG. 5A, FIG. 5B, FIG. 5C and FIG. 5D illustrate exemplary schematic diagrams of the bottom housing 402, the cam 414, the bridge assembly 406 and the terminal assembly 412 respectively of the contact system 104 in accordance with embodiments of the present disclosure. FIG. 5A illustrates an exemplary schematic view 500 of the bottom housing 402 showing a slot/groove 502 where the bridge assembly 406 can be engage to restrict its movement in one direction. As is evident from the view 500, the exemplary bottom housing 402 is configured to house three contact paths and corresponding bridge assemblies 406 catering to three phases.
[0052] FIG. 5B illustrates an exemplary schematic view 520 of the cam 414 showing slots 522 configured on the cam 414. There can be plurality of these slots 522, one corresponding to each bridge assembly 406 and configured such that when the slot 522 is positioned against the bridge assembly 406, the bridge assembly 406 moves radially inwards under force of the spring 410; and when the cam is rotated such that the slot 522 moves away from the bridge assembly 406, the slot 522 pushes the bridge assembly 406 radially outwards. Thus the cam 414 can be configured to cause radial movement of the bridge assemblies 406 by its rotation. The cam 414 can also incorporate a square hole 524 to receive the shaft 178 so that it rotates along with the shaft 178.
[0053] FIG. 5C illustrates an exemplary schematic view 540 of the bridge assembly 406 showing the moving contact 408 configured thereon. Also shown are projection 542 that can engage with the slot/groove 502 of the bottom housing 402 and a follower 544 that can be operatively coupled with the cam 414 to cause radial movement of the bridge assembly 406.
[0054] FIG. 5D illustrates an exemplary schematic view 560 of the terminal assembly 412 showing contact pad 562 configure thereon that can make contact with a corresponding contact pad configured on the moving contact 408 to make the contact path.
[0055] FIG. 6A, FIG. 6BandFIG. 6Cillustrate exemplary schematic views of the contact system 104 during operation from OFF to ON position in accordance with embodiments of the present disclosure. When the switch is in “off” position, position of the cam 414 and the bridge assemblies 406 can be as shown in view600 of FIG. 6A. In this position the bridge assemblies 406 can be in radially outward position breaking the contact between the moving contacts 408 and the terminal assembly 412. As the cam 414 is rotated, as shown in view 620 of FIG. 6B, the slots 522 of the cam 414 can come in alignment with the bridge assemblies 406 allowing the bridge assemblies 406 to move radially inwards under the force of the springs 410 and making the contact between the moving contacts 408 and the terminal assemblies 412. This position is shown in view 640 of FIG. 6C.
[0056] FIG. 7A, FIG. 7BandFIG. 7C illustrate exemplary schematic diagrams of the rotary mechanism indicating working of two stopper pins and a pin to restrict the movement of the switch to 60 degree in accordance with embodiments of the present disclosure. Shown therein is arrangement of two stopper pins 182 and pin 180. The pin 180 can be configured on the shaft 178 in a lateral position and placed between the two stopper pins 182 as shown in view 720 of FIG. 7B . The pin 180 can rotate along with rotation of the shaft 178 between the two stopper pins 182 thus the two stopper pins 182 work as stoppers for movement/rotation of the shaft 178 as shown in views 74 and 760 of FIG. 7A and FIG. 7B respectively. In the exemplary embodiment the two stopper pins 182 are configured to restrict the rotation to 60 degree.
[0057] FIG.8 illustrates an exemplary schematic view 800 of the rotary mechanism 102witha star shaped cam and a mechanism stopper in accordance with embodiments of the present disclosure. The rotary mechanism 102 can comprise of a mechanism housing 802 and a mechanism cover 804. The mechanism housing 802 can be configured with a star shaped cam 806 and a mechanism stopper 808 such that the two are operatively coupled to stop rotation of the star shaped cam 806 in certain positions. The star shaped cam 806 can be shaped to have v-shaped notches where the mechanism stopper 808 can engage and stop the rotation. It can also incorporate a square hole 812 to receive the shaft 178 so that it rotates along with the shaft 178. There can be a mechanism spring 810 configured to press the mechanism stopper 808 against the star shaped cam 806.
[0058] FIG. 9A, FIG. 9B and FIG. 9C illustrate exemplary schematic diagrams indicating working of a star shaped cam and mechanism stopper in accordance with embodiments of the present disclosure. When the star shaped cam 806 is rotated, it starts pushing the mechanism stopper 808 and compresses the mechanism spring 810. The mechanism stopper 808 on reaching the tip between two v-shaped notches of the star shaped cam 806 (as shown in view 900 of FIG. 9B) suddenly leads to an unstable condition in which the mechanism stopper 808 can move radially inwards under the force of the mechanism spring 810 leading to independent operation/rotation of the star shaped cam 806 by sliding to the other side of the star shaped cam 806 as shown in view 940 of FIG. 9C.
[0059] In an embodiment, the star shaped cam 806 and the cam 414 can be configured such that position of slots 522 on the cam 414 matches with one of the v-shaped notches on the star shaped cam 806 and this position can correspond to ‘ON’ position of the switch 100. The next v-shaped notch on the star shaped cam 806 can correspond to ‘OFF’ position of the switch 100. In the exemplary embodiment the star shaped cam 806 has 9 v-shaped notches therefore ‘ON’ to ‘OFF’ movement of the switch can correspond to 40 degree rotation of the switch handle 106. This 40 degree movement can be within the two stopper positions that are 60 degrees apart. Thus the switch movement can take place beyond ‘ON’ and ‘OFF’ positions but can be restricted by 60 degree limit set by stoppers.
[0060] In an embodiment of application, When the switch handle 106 is actuated from ‘OFF’ to ‘ON’ position, the star shaped cam 806 coupled to the switch handle 106 through the shaft 178 starts moving and compresses the mechanism spring 810. The cam 414 of the contact system 104 also gets actuated as it is also coupled to the star shaped cam 806 and the shaft 178 and starts rotating. The mechanism stopper 808 on reaching the tip of the star shaped cam 806 suddenly leads to an unstable condition leading to independent operation sliding to the other side of the tip. The mechanism stopper 808 can then engage with the next v-shaped notch that coincides with the position in which slots 522 on the cam 414 of the contact system 104 align with the bridge assemblies 406 which can result in contacts being made.
[0061] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0062] The present disclosure provides a rotary switch capable of making, carrying and breaking current in a low voltage circuit.
[0063] The present disclosure provides a rotary switch with multiple contact paths in a single stage.
[0064] The present disclosure provides a rotary switch capable of withstanding short circuit conditions up to 1 second.
[0065] The present disclosure provides a rotary switch capable of diverse applications.
[0066] The present disclosure provides a rotary switch design that prevents internal arcing and flashover.
[0067] The present disclosure provides a rotary switch that has adequate venting.
[0068] The present disclosure provides a rotary switch that has reduced depth thus overcoming the problem of installing switches in panels which have lesser depths for mounting.