Claims:1. A rotary operated mechanism for circuit breakers comprising:
a housing;
an operating knob;
a gearing mechanism operatively coupled to said operating knob wherein the gearing mechanism comprises of a central gear and a driven gear that is further operatively connected with a crank wherein rotation of the central gear results in further rotation of the driven gear that further rotates the crank; and
a sliding pin operatively coupled to the crank at one end and to a slider at other end wherein the slider ensures operations of the switchgear/MCCB.
2. The mechanism as claimed in claim 1, wherein said operating knob is configured between ON, OFF and TRIP conditions.
3. The mechanism as claimed in claim 1, wherein said operating knob is the interaction point between user and the switchgear/MCCB.
4. The mechanism as claimed in claim 1, wherein said central gear and driven gear are spur gears that are operated in a single plane.
5. The mechanism as claimed in claim 1, wherein said gearing mechanism further comprises of a crank pin that is the interaction point between the operating knob and the rotary operated mechanism.
6. The mechanism as claimed in claim 5, wherein the crank pin performs to and fro movement linearly and ensures the operation of switchgear/MCCB by providing a linear motion to the slider.
7. The mechanism as claimed in claim 1, wherein said central gear ensures a 1200 standard operation between ON and OFF condition of the switchgear/MCCB.
8. The mechanism as claimed in claim 1, wherein said central gear is configured to create a reduction to the driven gear such that the central gear rotates more than the driven gear to ensure that the required travel is provided to the slider via the crank.
9. The mechanism as claimed in claim 1, wherein said slider is directly guided by the operating knob of the circuit breaker thereby eliminating need of a separate guiding assembly.
, Description:TECHNICAL FIELD
[0001] The present disclosure relates generally to circuit breakers for protecting electrical circuits against overload and short circuit conditions. In particular, the present invention relates to a low voltage current limiting circuit breaker that protects and isolates current supply in an electrical circuit.

BACKGROUND
[0002] Typically, circuit breakers act as a switching and protecting devices wherein fault current are tripped and/or isolated during abnormal conditions such as short-circuit, overload and under voltage. These circuit breakers consist of one or more electric poles whose number is determined by their application such as single pole circuit breaker, two pole circuit breaker and so on. They are designed for use in switchboards, control panels, and combination starters for effective single location current distribution and control. Additionally, these circuit breakers are housed inside an enclosure to provide safety to users operating the same.
[0003] United States Patent US5493083 A discloses a rotary control device for circuit breaker that includes a front plate having an opening through which a crank pin extends wherein the crank pin is pivotally configured between a first and a second position. The rotary control device further includes a housing, and a rotary handle mounted on the housing wherein the rotary handle is rotatable between a first and a second position corresponding to the first and the second position of the crank pin. However, design of the rotary control device is complex and does not clearly address issues of simplicity and force reduction at user’s end.
[0004] United States Patent US6518526 B2 discloses a handle operating mechanism for a circuit breaker that includes a rotary operating knob for opening and closing a main circuit contact of a circuit breaker, a rotating gear that is connected to an operating knob and provides a first engaging device, and a contact opening and closing mechanism that is configured with a toggle gear that meshes with the rotating gear. A clutch gear is also connected to the operating knob that can be interposed between the operating knob and the rotating gear, and has a second engaging device.
[0005] United States Patent 6969813 discloses a direct mount rotary handle operating mechanism for use with circuit breakers wherein handle mechanism includes a driver that is coupled to a circuit breaker and a handle that incorporates a socket for receiving the driver. The socket is configured to allow the handle to rotate relative to the driver. The handle further includes a movable locking pin. A lock latch is further associated with the driver, wherein the lock latch includes a flange portion. However, the operating principle of above prior arts is based on motion transformation in perpendicular planes and thereby increases overall dimensions of the system.
[0006] Evidently, present technology for rotary mechanism construction uses a complex combination of gears or linkages to convert the rotary motion of handle into linear motion of the breaker. This approach has higher operating forces at the handle which causes inconvenience to user. Further, this rotary mechanism has lower mechanical endurance and involves guiding the internal components to achieve the linear motion. Also, these mechanisms are prone to jamming, incorrect indication and higher wear and tear due to large number of components incorporated therewithin.
[0007] Thus there is a need of simple and effective rotary operated mechanism which incorporates lower number of components, a lower operating force, higher mechanical endurance limit, and is easy to assemble and operate.

OBJECTS OF THE INVENTION
[0008] A general object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that can be used with all kind of transmission and distribution switchgears having various size, shapes and current carrying capacities.
[0009] Another object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that can be used with switchgears having any number of poles/phases.
[0010] Another object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that incorporates robust and cost effective design.
[0011] Another object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that is highly reliable.
[0012] Another object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that is easy to manufacture.
[0013] Another object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that is easy to assemble.
[0014] Another object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that has higher mechanical endurance.
[0015] Another object of the present disclosure is to provide a rotary operated mechanism for circuit breakers that reduces overall operating forces of the circuit breaker.

SUMMARY
[0016] The present disclosure relates generally to circuit breakers for protecting electrical circuits against overload and short circuit conditions. In particular, the present invention relates to a low voltage current limiting circuit breaker that protects and isolates current supply in an electrical circuit. The present disclosure discloses a rotary operated mechanism for circuit breakers that consists of a housing, an operating knob, and a gearing mechanism operatively coupled to the operating knob, and a sliding pin operatively coupled to a crank at one end and to a slider at other end wherein the slider ensures operations of the switchgear/MCCB. In an embodiment, the operating knob is configured between ON, OFF and TRIP conditions and it is the interaction point between user and the switchgear/MCCB.
[0017] In an aspect, the gearing mechanism comprises of a central gear and a driven gear that is further operatively connected with a crank wherein rotation of the central gear results in further rotation of the driven gear that further rotates the crank. Additionally, central gear and driven gear are spur gears that are operated in a single plane and the gearing mechanism further comprises of a crank pin that is the interaction point between the operating knob and the rotary operated mechanism. In an embodiment, the crank pin performs to and fro movement and ensures the operation of switchgear/MCCB by providing a linear motion to the slider.
[0018] In an embodiment, the central gear ensures a 1200 standard operation between ON and OFF condition of the switchgear/MCCB. Further, central gear is configured to create a reduction to the driven gear such that the central gear rotates more than the driven gear to ensure that the required travel is provided to the slider via the crank. In an embodiment, the slider is directly guided by the operating knob of the circuit breaker thereby eliminating need of a separate guiding assembly.
[0019] In an aspect, the present disclosure provides a rotary operated mechanism for circuit breakers that provides a clear indication of the current state of the internal contacts of the circuit breaker to the user and also provides necessary electrical isolation and safety. Further, the mechanism is easy to manufacture and assemble and keeps operating force within ergonomic limit of human operation.

BRIEF DESCRIPTION OF THE DRAWINGS
[0020] 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.
[0021] Fig. 1 illustrates an exemplary representation of a rotary operated mechanism being mounted on an MCCB in accordance with embodiments of the present disclosure.
[0022] Fig. 2A illustrates an exemplary switching device or an MCCB in ON condition, along with the operating knob in accordance with embodiments of the present disclosure.
[0023] Fig. 2B illustrates an exemplary switching device or an MCCB in OFF condition, along with the operating knob in accordance with embodiments of the present disclosure.
[0024] Fig. 3 illustrates an exemplary representation of the back view of a rotary operated mechanism in accordance with embodiments of the present disclosure.
[0025] Fig. 4 illustrates an exemplary meshing of central gear and driven gear of the rotary operated mechanism in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION
[0026] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details 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.
[0027] Embodiments explained herein relate to circuit breakers for protecting electrical circuits against overload and short circuit conditions. In particular, the present invention relates to a low voltage current limiting circuit breaker that protects and isolates current supply in an electrical circuit. The present disclosure discloses a rotary operated mechanism for circuit breakers that consists of a housing, an operating knob, and a gearing mechanism operatively coupled to the operating knob, and a sliding pin operatively coupled to a crank at one end and to a slider at other end wherein the slider ensures operations of the switchgear/MCCB. In an embodiment, the operating knob is configured between ON, OFF and TRIP conditions and it is the interaction point between user and the switchgear/MCCB.
[0028] In an aspect, the gearing mechanism comprises of a central gear and a driven gear that is further operatively connected with a crank wherein rotation of the central gear results in further rotation of the driven gear that further rotates the crank. Additionally, central gear and driven gear are spur gears that are operated in a single plane and the gearing mechanism further comprises of a crank pin that is the interaction point between the operating knob and the rotary operated mechanism. In an embodiment, the crank pin performs to and fro movement and ensures the operation of switchgear/MCCB by providing a linear motion to the slider.
[0029] In an embodiment, the central gear ensures a 1200 standard operation between ON and OFF condition of the switchgear/MCCB. Further, central gear is configured to create a reduction to the driven gear such that the central gear rotates more than the driven gear to ensure that the required travel is provided to the slider via the crank. In an embodiment, the slider is directly guided by the operating knob of the circuit breaker thereby eliminating need of a separate guiding assembly.
[0030] In an aspect, the present disclosure provides a rotary operated mechanism for circuit breakers that provides a clear indication of the current state of the internal contacts of the circuit breaker to the user and also provides necessary electrical isolation and safety. Further, the mechanism is easy to manufacture and assemble and keeps operating force within ergonomic limit of human operation.
[0031] Fig. 1 illustrates an exemplary representation of a rotary operated mechanism being mounted on an MCCB wherein housing 102 essentially forms enclosure for assembly and support of the rotary operated mechanism. An exemplary housing of the MCCB 104 is also illustrated to depict the compact and robust design of the rotary operated mechanism.
[0032] Fig. 2A illustrates an exemplary switching device or an MCCB in ON condition, wherein operating knob 202 is coupled with central gear of the rotary operated mechanism and it is arranged in such a way that the rotary operated mechanism ensures the flow of steady current through the switchgear or the MCCB. On the other hand, Fig. 2B illustrates an exemplary switching device or an MCCB in OFF condition wherein operating knob 202 is coupled with central gear of the rotary operated mechanism and it is arranged in such a way that the rotary operated mechanism stops the flow of current through the switchgear or the MCCB and ensures that the MCCB does not conduct electricity whilst the MCCB is in OFF condition.
[0033] In an aspect, the operating knob 202 can also be configured to a trip condition that resembles the tripping of the rotary operated mechanism and thereby stopping the flow of fault current being transmitted through the MCCB.
[0034] Fig. 3 illustrates an exemplary representation of the back view of a rotary operated mechanism wherein a central gear 302 is configured to mesh with a driven gear 304. The central gear 302 is operatively coupled with an operating knob 202 that provides a rotary motion to the central gear 302. Further, the rotary motion of the central gear 302 rotates the driven gear 304 that is further configured with a crank 306. The crank 306 is connected to the driven gear 304 at one end and to a sliding pin 308 at other end. The sliding pin 308 is operatively configured with a slider 310 that ensures operations of a switchgear/MCCB by providing open or close connections to the current carrying conductors of the switchgear/MCCB.
[0035] In an embodiment, the crank 306 is connected to the driven gear 304 with the help of a crank pin 312 which is the interaction point between the operating knob 202 and the rotary operated mechanism 100. The crank pin 312 performs to and fro movement and ensures the operation of the MCCB by providing movement to the crank 306 and thus providing a linear movement to the sliding pin 308.
[0036] Fig. 4 illustrates an exemplary meshing of central gear 302 and driven gear 304 of the rotary operated mechanism wherein a central gear 302 is configured to mesh with a driven gear 304. The central gear 302 is operatively coupled with an operating knob 202 that provides a rotary motion to the central gear 302. Further, the rotary motion of the central gear 302 rotates the driven gear 304 that is further configured with a crank 306. The crank 306 is connected to the driven gear 304 at one end and to a sliding pin 308 at other end. The sliding pin 308 is operatively configured with a slider 310 that ensures operations of a switchgear/MCCB by providing open or close connections to the current carrying conductors of the switchgear/MCCB.
[0037] In an aspect, central gear 302 not only transfers motion across the mechanism but also ensures a 120 degree standard operation between ON and OFF condition. The central gear 302 creates a reduction to driven gear 304 and this reduction of speed also ensures a reduction of the total angle rotated to get the required travel. Thus essentially, the central gear 302 rotates more than the driven gear 304 to ensure the required travel is provided to the breaker via a crank 306. The crank 306 is connected to a slider 310 via a sliding pin 308. In unassembled condition of the rotary operated mechanism 100, the slider 310 is in a free state. But when assembled with the circuit breaker, the slider 310 is directly guided by the operating knob 202 of the circuit breaker thereby eliminating the need of a separate guiding assembly and also providing a smoother operation because the mechanism is not over-constrained.
[0038] 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
[0039] The present disclosure provides a rotary operated mechanism for circuit breakers that can be used with all kind of transmission and distribution switchgears having various size, shapes and current carrying capacities.
[0040] The present disclosure provides a rotary operated mechanism for circuit breakers that can be used with switchgears having any number of poles/phases.
[0041] The present disclosure provides a rotary operated mechanism for circuit breakers that incorporates robust and cost effective design.
[0042] The present disclosure provides a rotary operated mechanism for circuit breakers that is highly reliable.
[0043] The present disclosure provides a rotary operated mechanism for circuit breakers that is easy to manufacture.
[0044] The present disclosure provides a rotary operated mechanism for circuit breakers that is easy to assemble.
[0045] The present disclosure provides a rotary operated mechanism for circuit breakers that has higher mechanical endurance.
[0046] The present disclosure provides a rotary operated mechanism for circuit breakers that reduces overall operating forces of the circuit breaker.