CLIAMS:1. A molded case circuit breaker comprising:
an actuation mechanism comprising a knob, an actuation mechanism fork, and a mechanism pin, wherein the actuation mechanism is configured to move between positions that correspond to ON, OFF, TRIP, and RESET positions of the knob; and
one or more release mechanisms configured to provide one or more of under voltage release and shunt release, wherein the one or more release mechanisms comprise an actuator configured with a cam that is operatively coupled with the mechanism pin, and wherein the cam is configured to provide adequate over travel to the actuator when the knob is moved from RESET to OFF position.
2. The molded case circuit breaker of claim 1, wherein the actuation mechanism is configured to latch the actuator of the one or more release mechanisms when moved from TRIP to RESET position and further configured to return to OFF position from the RESET position.
3. The molded case circuit breaker of claim 1, wherein the actuation mechanism fork is configured to pivot about a mechanism fork hinge as the knob is moved between any two of the ON, OFF, TRIP, and RESET positions.
4. The molded case circuit breaker of claim 1, wherein the mechanism pin moves along with the actuation mechanism fork as the knob is moved between any two of the ON, OFF, TRIP, and RESET positions, and wherein the mechanism pin defines a locus of movement.
5. The molded case circuit breaker of claim 4, wherein the cam comprises multiple surfaces.
6. The molded case circuit breaker of claim 5, wherein the surfaces are configured to provide required travel to the actuator before the actuator mechanism reaches OFF position.
7. The molded case circuit breaker of claim 5, wherein the one or more surfaces are configured to allow the mechanism pin rotate without the actuator moving any further.
8. The molded case circuit breaker of claim 5, wherein one or more surfaces are configured to join the first surface and the second surface and provide a small over travel movement to the actuator.
,TagSPECI:TECHNICAL FIELD
[0001] The present invention relates generally to the field of circuit breakers and more particularly to a molded case circuit breaker (MCCB) incorporated with under-voltage (UV) and shunt (SH) release devices.

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] Circuit breakers are incorporated in power supply circuits to provide means to make/break the power supply as and when required. Circuit breakers can be designed to either manually interrupt the power supply circuit or automatically trip to discontinue the power supply under certain undesirable conditions. Some of them are provided with tripping mechanism known as shunt release that can be operated from remote.
[0004] An under voltage release is a device that triggers the breaker to open when the applied voltage falls below a predefined threshold value and is used in circuit breaker to offer protection to downstream equipment from under voltage or zero voltage conditions. Often, an under voltage release is operated from the system and is intended to cause the breaker to open in the event something happens to cause the system voltage to collapse Hence it goes along with the circuit breaker module as an internal accessory.
[0005] A shunt release is a solenoid device that mechanically triggers the breaker to open. It in turn can be triggered by any number of protective or control functions but mainly used for remote tripping by application of a control supply voltage. Both UV and shunt release use electromagnetic coil to provide the trip signal.
[0006] Conventional Moulded Case Circuit Breakers (referred here after as MCCB or circuit breaker or simply as breaker) have provisions for Under-voltage Release as well as Shunt Release. Under-voltage Release as well as Shunt Release are not part of the basic circuit breaker, instead they come as separate package/accessory and have to be inserted in the cavities designed to accommodate them in the basic MCCB for their functional operation. Generally they are be inserted in the trip condition of breaker, then they get aligned with basic breaker and start functioning.
[0007] Both under voltage release (also referred as UV and the terms used interchangeably hereinafter) and shunt release (also referred as shunt or SH and the terms used interchangeably hereinafter) have provision of connecting two wires into them. UV release, as it performs the function of tripping the MCCB when the applied voltage drops below predetermined value, is typically connected across supply voltage. The shunt release being remotely operated, it is connected to a power source from the actuating device.
[0008] Both under voltage release and shunt release have two stable states - trip and latch and they are generally in latch condition and shift to trip condition when actuated. Operation sequence of the voltage release and shunt release in a MCCB of includes following steps - breaker in ON condition, actuation command to UV / SH, de-latching of UV / SH, tripping of the MCCB, MCCB in trip condition, MCCB knob travel from Trip to reset position, UV/SH actuator travel to latch position (along with MCCB mechanism), breaker in OFF position & accessories latched (assuming actuation command is removed).
[0009] Make and break operations in a circuit breaker are typically carried out by engaging and disengaging a pair of contacts one of which is moving contact supported by a pivoting contact arm and the other a fixed contact that is substantially stationary. The contact arm is pivoted by an operating mechanism such that the movable contact supported by the contact arm can be engaged and disengaged from the fixed contact. The operating mechanism can disengage or disengage the contacts two modes: the circuit breaker operating handle/ knob can be used to activate the operating mechanism alternatively a tripping mechanism, such as an under-voltage (UV) release device or a shunt (SH) release device, in response to an unacceptable levels of voltage or under a remote command, can activate the operating mechanism. For many circuit breakers, the operating handle/ knob is coupled to the operating mechanism such that when the tripping mechanism activates the operating mechanism to separate the contacts, the operating handle moves to a fault or tripped position
[0010] Circuit breakers come in different sizes and design and are incorporated with different type of construction details which causes them to have a different or common position for OFF and RESET button or knob. In some case, the knob requires to move beyond the OFF position for resetting (RESET) the circuit breaker. In others, there can be a common position for OFF and RESET that is the OFF position itself is the RESET position. RESET knob or button or lever of circuit breaker is also coupled with the UV/SH actuator of UV and/or SH release device. Circuit breaker incorporating different position from OFF and RESET have the disadvantage that the circuit breaker can trip, in certain circumstances, during circuit breaker ON position even when there is no under-voltage condition or when no command is present for operation of circuit breaker. This can be because of the critical tolerance requirements for over travel (OT) condition specially for MCCB that have a different OFF and RESET position. In such cases, when circuit breaker knob is in OFF position and trip command is received/generated, it can cause the UV/SH actuator to get de-latched and remain in de-latched condition causing trip command to be generated (even without a trip command/signal) when circuit breaker is brought to ON position.
[0011] There is therefore a need in the art to design and develop systems and methods by which above shortcomings in under-voltage and shunt release devices/accessories for MCCB can be overcome and which can enhance the reliability of such devices.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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
[0017] It is an object of the present disclosure to provide a UV / shunt release that prevents midway tripping of circuit breaker during shifting of circuit breaker knob to ON position due to de-latched UV / SH even when actuating command has gone OFF before switching ON the breaker.
[0018] It is an object of the present disclosure to provide a UV / shunt release that limits the travel of UV / shunt release actuator to required point relative to knob mechanism while ensuring latching of the release.
[0019] It is an object of the present disclosure to provide a UV / shunt release actuator with improved cam profile that meets the above objectives.

SUMMARY
[0020] The present invention relates generally to an under voltage / shunt release incorporated with MCCBs to break power supply during under voltage conditions through under voltage release or remotely trip the circuit using shunt release.
[0021] In an embodiment, the disclosed under voltage and shunt release can be provided with an UV/SH release actuator (also referred to as UV/SH actuator or release actuator or simply release and the terms used interchangeably hereinafter) configured such that during resetting operation, the UV/SH release has adequate over travel without crossing OFF position of knob of the circuit breaker. In an aspect this can ensure that the UV/SH release does not remain de-latched when the breaker knob has returned to OFF position after the resetting operation. In another aspect, finishing the over travel before crossing the OFF position can prevent midway tripping of circuit breaker during shifting of circuit breaker knob to ON position due to de-latched UV / SH even when actuating command has gone OFF before switching ON the breaker.
[0022] In an embodiment, the actuator can incorporate a cam operatively coupled to actuating mechanism (also referred to as knob mechanism and the two terms used interchangeably) of the MCCB wherein the cam is configured such that resetting operation of the knob and its further return to OFF position can actuate the UV/SH release to latch and provide for over travel without crossing the OFF position of the knob. Thus the release actuator can be clear of the knob in knob’s OFF position.
[0023] In an embodiment, the cam of the UV/SH release actuator can be provided with a number of surfaces each meeting a functional requirement. In an aspect of the present disclosure, number of cam surfaces on the actuator can be three wherein first cam surface in engagement with a mechanism pin of the knob mechanism of the MCCB can provide required travel to the release actuator before breaker OFF position. The second cam surface can be configured to follow locus of movement of the mechanism pin at the over travel position, such that it allows the mechanism pin to slip out without the actuator moving any further. The third cam surface can join the first surface and the second surface and on this surface movement of the actuator can be very small and can form a part of the over travel.
[0024] In an aspect, UV/SH actuator with cam surfaces of the present disclosure can be an improvement on the UV/SH actuators of prior art that do not incorporate a cam and providing solution to limitation of existing UV/SH actuators.
[0025] 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
[0026] 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.
[0027] FIG. 1 illustrates an exemplary schematic view of an existing actuator for a UV/SH release device in accordance with prior art.
[0028] FIG. 2 illustrates an exemplary schematic diagram indicating knob positions in a typical MCCB in accordance with an embodiment of the present disclosure.
[0029] FIG. 3 illustrates an exemplary UV/SH actuator of a UV/SH release in accordance with an embodiment of the present disclosure.
[0030] FIG. 4A and FIG. 4B illustrate exemplary schematic views of a MCCB configured with UV/SH release in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.
[0036] The present invention relates generally to an under voltage / shunt release incorporated with MCCBs to break power supply during under voltage conditions through under voltage release or remotely trip the circuit using shunt release.
[0037] MCCB mechanisms have different constructions which results in common or different OFF and RESET positions of the knob. In some MCCB mechanisms, knob has to travel a few degrees beyond OFF position to reset the circuit breaker (known as RESET position of the knob); when released after resetting, the knob comes back to OFF position. While some other MCCB mechanisms have a common OFF and RESET position of the knob. The present disclosure relates to a MCCB having a mechanism with different OFF and RESET positions.
[0038] While the knob is moved to the RESET position the mechanism moves UV / SH actuator back to its latched position. Typically UV / SH release can travel more after its latched condition and this travel is known as over travel (OT). The breakers are designed such that the over travel requirement is met before the OFF position of the knob, so that the UV / SH actuator in its latched condition is clear from the knob in OFF condition. As OFF to RESET travel of the breaker is small, getting over travel within this small travel is difficult and tolerances become more critical. Also if over travel requirement of the UV / SH release is met before breaker OFF position, the knob travel after OFF will move UV / SH actuator beyond OT limits.
[0039] Further, meeting the over travel requirement beyond OFF position of the knob shall result the UV/SH release remaining de-latched when the breaker knob has returned to OFF position after the resetting operation. In another aspect, finishing the over travel before crossing the OFF position can prevent midway tripping of circuit breaker during shifting of circuit breaker knob to ON position due to de-latched UV / SH even when actuating command has gone OFF before switching ON the breaker.
[0040] To overcome above mentioned problem an actuator which can provide sufficient over travel to UV / SH release before knob OFF position so that latching of the UV / SH release is ensured.
[0041] In an embodiment, the disclosed under voltage and shunt release can be provided with an actuator configured such that during resetting operation, the UV/SH release has adequate over travel without crossing OFF position of knob of the circuit breaker. In an aspect this can ensure that the UV/SH release does not remain de-latched when the breaker knob has returned to OFF position after the resetting operation. In another aspect, finishing the over travel before crossing the OFF position can prevent midway tripping of circuit breaker during shifting of circuit breaker knob to ON position due to de-latched UV / SH even when actuating command has gone OFF before switching ON the breaker.
[0042] In an embodiment, actuator can incorporate a cam operatively coupled to actuation mechanism (alternatively referred to as knob mechanism) of the MCCB wherein the cam is configured such that resetting operation of the knob and its further return to OFF position can actuate the UV/SH release to latch and provide for over travel without crossing the OFF position of the knob. Thus the release actuator can be clear of the knob in knob’s OFF position.
[0043] In an embodiment, the cam of the UV/SH release actuator can be provided with a number of surfaces each meeting a functional requirement. In an aspect of the present disclosure, number of cam surfaces on the actuator can be three wherein first cam surface in engagement with a mechanism pin of the knob mechanism of the MCCB can provide required travel to the release actuator before breaker OFF position. The second cam surface can be configured to follow locus of movement of the mechanism pin at the over travel position, such that it allows the mechanism pin to slip out without the actuator moving any further. The third cam surface can join the first surface and the second surface and on this surface movement of the actuator can be very small and can form a part of the over travel.
[0044] In an aspect, UV/SH actuator with cam surfaces of the present disclosure can be an improvement on the UV/SH actuators of prior art that do not incorporate a cam and providing solution to limitation of existing UV/SH actuators.
[0045] FIG. 1 illustrates an exemplary schematic view 100 of existing typical actuator 102 for a UV/SH release used in MCCB in accordance with prior art. The actuator in accordance with prior art does not specifically incorporate means to mitigate problems related to over travel and therefore has to be accurately manufactured to close tolerances.
[0046] FIG. 2 illustrates an exemplary schematic diagram 200 indicating knob positions in a typical MCCB in accordance with an embodiment of the present disclosure wherein the knob 202 of the MCCB 204 can take different positions such as ON position 202-1, TRIP position 202-2, OFF position 202-3 and RESET position 202-4. In an aspect, the knob 202 can be coupled to UV and/or SH release In another aspect, UV and/or SH release device can be incorporated in the MCCB in trip condition of MCCB for proper alignment In yet another aspect, UV release and SH release can have two stables states – a latched condition and a trip position/state. Generally UV/SH release can be in latch condition and goes to trip condition when actuated. In latch condition, knob 202 can be at position 202-1 or off position 202-3. Actuation of either UV release due to under-voltage condition or SH release operated remotely through a voltage pulse, can cause the MCCB to trip with knob 402 moving to TRIP position 202-2. MCCB knob 202 can be moved further from TRIP position 202-2 to RESET position 202-4 thereby moving UV/SH actuator (not shown) to latch position. MCCB knob 202 can then move to OFF position 202-3.
[0047] Referring now to FIG. 3 wherein an actuator 300 for the UV/SH release is disclosed in accordance with an embodiment of the present disclosure. As illustrated therein the actuator 300 can incorporate a cam wherein the cam can be operatively coupled to knob mechanism through a mechanism pin and configured such that resetting operation of the knob and its further return to OFF position can actuate the UV/SH release to latch and provide for over travel without crossing the OFF position of the knob. Thus the release actuator can be clear of the knob in knob’s OFF position.
[0048] In an embodiment, the cam of the UV/SH release actuator can be provided with a number of surfaces each meeting a functional requirement. In an aspect of the present disclosure, number of cam surfaces on the actuator can be three wherein first cam surface 302 can provide required travel before breaker OFF position. A second cam surface 304 can be configured to follow locus of movement of the mechanism pin (not shown here and described in subsequent paragraphs) at the over travel position, such that it allows the mechanism pin to continue with its further movement without actuator 300 moving any further. A third cam surface 306 can join the first surface 302 and the second surface 304 and on this surface movement of the actuator 300 can be very small and can form a part of the over travel.
[0049] FIG. 4A and FIG. 4B illustrate exemplary schematic views of a MCCB configured with UV/SH release in accordance with an embodiment of the present disclosure wherein the actuator 300 of the UV/SH release is shown integrated with knob mechanism of a MCCB. The knob mechanism of the MCCB can comprise a knob 202, an actuation mechanism fork 404 and a mechanism pin 410. The actuation mechanism fork 404 can pivot about a mechanism fork hinge 406. The UV/SH release actuator 300 can be operatively coupled to the mechanism pin 410 such that when the knob 202 is moved from trip position 202-2 to reset position 202-4, making the mechanism fork 404 to move about the mechanism fork hinge 406, the mechanism pin 410 can make the actuator 300 to move by engaging with cam surfaces 302, 304 and 306.
[0050] In an embodiment, the first cam surface 302 can provide required travel for actuator 300 before circuit breaker reaches OFF position 202-3. The second cam surface 304 can follow locus movement of mechanism pin 410 as indicated in FIG. 4B wherein the locus movement of mechanism pin 410 is shown as 452. The configuration of the second cam surface 304 can allow the mechanism pin 410 to slip out without any further movement of the actuator 300. In an aspect, such a system can provide for required over travel a few degrees before OFF position of knob 202.
[0051] In an aspect, actuator 300 with suitably designed cam surfaces can provide UV/SH release of present disclosure with sufficient over travel (OT) before the breaker reaches OFF position, that is, UV/SH actuator can get latched before the OFF position of the knob.
[0052] In an aspect, UV/SH actuator 300 with cam surfaces of the present disclosure can be an improvement on the existing UV/SH actuators 102 (without cam surfaces) and allow for overcoming the limitation of existing UV/SH actuators 102 (without cam surfaces) especially when used with MCCB which can have a mechanism with separate knob position for OFF and RESET.
[0053] 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
[0054] The present disclosure provides an UV / shunt release that prevents midway tripping of circuit breaker during shifting of circuit breaker knob to ON position due to de-latched UV / SH even when actuating command has gone OFF before switching ON the breaker.
[0055] The present disclosure provides an UV / shunt release that limits the travel of UV / shunt release actuator to required point relative to knob mechanism while ensuring latching of the release.
[0056] The present disclosure provides an UV / shunt release actuator with improved cam profile that meets the above objectives.