Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to a miniature circuit breaker (MCB), and more specifically, relates to an optimized actuating mechanism for a miniature circuit breaker with a reduced number of components.

BACKGROUND
[0002] The existing miniature circuit breaker (MCB) actuating mechanisms typically involve components such as an actuating arm, U-shaped linkage, tripping lever, moving contact holder lever, spring, retention lever, moving contact, and fixed contact. However, the existing mechanism suffers from limitations that include a lack of how contact pressure is achieved between the moving contact and the fixed contact. Notably absent is any mention of a main spring, which is a critical component for ensuring effective contact pressure within the MCB.
[0003] Secondly, the existing state of the art fails to elucidate the mechanism by which the actuating arm returns in the opposite direction. There is no mention of a knob spring or the force required for the actuating arm to return to its original position. The absence of such information, implies a potential need for an external force to reposition the actuating arm to the open condition, introducing complexity and potential inconvenience.
[0004] Lastly, the existing state of the art does not provide insights into how the mechanism trips in the case of thermal or overload conditions. This omission raises concerns about the overall safety and effectiveness of the circuit interruption device under such circumstances.
[0005] Therefore, it is desired to overcome the drawbacks, shortcomings, and limitations associated with existing solutions, and develop the actuating mechanism with fewer components to achieve the required functions of ON, OFF, and Trip, with optimized material usage, reduced cost, and ease of manufacture.

OBJECTS OF THE PRESENT DISCLOSURE
[0006] An object of the present disclosure relates, in general, to a miniature circuit breaker (MCB), and more specifically, relates to an optimized actuating mechanism for a miniature circuit breaker with a reduced number of components.
[0007] Another object of the present disclosure is to provide a mechanism in which the utilization of a reduced number of components in the MCB actuation mechanism, coupled with design considerations for design for manufacturability (DFM) and design for assembly (DFA), leads to a significant reduction in both component costs and assembly expenses.
[0008] Another object of the present disclosure is to provide a mechanism that reduces manufacturing costs and also contributes to easier maintenance.
[0009] Another object of the present disclosure is to provide a mechanism that is realized through reduced component costs, simplified assembly, and efficient manufacturing that can be passed on to customers, making the MCB actuation mechanism more cost-effective for end-users.
[0010] Yet another object of the present disclosure is to provide a mechanism with fewer components that enhance the quality and consistency of the MCB actuation mechanism.

SUMMARY
[0011] The present disclosure relates, in general, to a miniature circuit breaker (MCB), and more specifically, relates to an optimized actuating mechanism for a miniature circuit breaker with a reduced number of components. The main objective of the present disclosure is to overcome the drawback, limitations, and shortcomings of the mechanism and solution, by providing an actuating mechanism of the miniature circuit breaker (MCB) disclosed herein features a pivotally mounted knob in a housing, enabling rotational operation to switch between close, open, and trip states. A contact holder, securely fastened to a moving contact, pivots on a kinematic pin for controlled movement. A U-pin, pivotally mounted in the knob, engages a latch feature provided on the contact holder, transferring force to a trip latch after predefined knob rotation. Unique latch profiles eliminate the need for additional guiding components and special finishes. The contact holder includes a groove restricting U-pin movement. The MCB's rotational operation facilitates close, open, and trip states, ensuring reliable electrical connectivity. Specific knob rotations align with MCB specifications for optimal performance. The actuating mechanism integrates diverse functions, simplifying structure and enhancing operational efficiency, including latching, guiding U-pin movement, providing structural support, and acting as a main spring anchor. Additionally, a bimetallic strip and a short-circuit release mechanism with a hammer enable overload and short-circuit releases, respectively. The trip latch serves dual roles, featuring a protrusion which eliminates specific surface finish for efficient re-setting.
[0012] The miniature circuit breaker (MCB) that utilizes the actuating mechanism to close both fixed and moving contacts through the actuator or knob. The same mechanism facilitates tripping the MCB in case of a fault, causing the contacts to open rapidly. The MCB functions as an overload and short-circuit protection device. Whenever a fault occurs, the MCB trips, cutting off the power supply. The actuating mechanism takes care of resetting to its initial position, ready to switch ON again with the next operation of the actuator or knob. The mechanism trips with the help of a bimetal in the case of an overload condition and with the assistance of a solenoid coil in the case of an overcurrent/short-circuit condition.
[0013] The present disclosure relates to the actuating mechanism of the miniature circuit breaker (MCB). The actuating mechanism includes a knob that is pivotally mounted in a housing to facilitate rotational operation for switching the MCB to close, open and trip states. A contact holder securely fastened to a moving contact, both pivotally mounted on a kinematic pin within the housing to enable controlled movement of the MCB. A U-pin is pivotally mounted at one end within the knob and securely latched onto a latch portion of the contact holder at the other end, the U-pin is responsive to the rotational movement of the knob with the U-pin located between the latch portion and a trip latch, wherein the latch portion incorporates a unique profile that enables the U-pin to transfer force on the trip latch after the predefined rotation of the knob, eliminating additional components to guide the U-pin and eliminating special finish requirements for gliding surfaces of latches. A groove accommodated on the contact holder constrains the movement of the U-pin in trip condition. A knob spring exerts a force on the knob and transfers to the U-pin through a protrusion, wherein a middle position of the knob serves as an indicator for the tripped state of contacts, obtained through the manipulation of the knob spring. A fixed contact affixed to the housing to establish a stable point of contact with the moving contact to ensure reliable and proper electrical connectivity, wherein the rotational operation of the knob configured to facilitate switching the MCB to the close state allowing the moving contact to establish contact with the fixed contact, facilitate switching the MCB to the open state causing the moving contact to separate from the fixed contact and facilitate switching the MCB to the trip state causing the moving contact to separate from the fixed contact.
[0014] In an aspect, at the open state, the MCB is configured to initiate the U-pin toggling through rotation of the knob. Exert force on the knob by the knob spring to pull the U-pin. Initiate pivotal shift by the kinematic pin when the moving contact and the fixed contact begin to separate disrupting an electrical connection and apply force on the contact holder and the fixed contact by the main spring in opposite directions, generating a torque for accelerated opening of the moving contact and the fixed contact. The predefined rotation of the knob is determined by the MCB specifications for optimal contact performance.
[0015] In another aspect, at the close state, the MCB is configured to exert pressure on the U-pin in response to the rotational movement of the knob. Push the contact holder away from the latch portion against the main spring as a result of the pressure applied to the U-pin. Facilitate a pivotal movement of the moving contact and the fixed contact during the closing operation along an axis defined by the kinematic pin. Employ the latch spring to exert force on the trip latch during a closing operation, maintaining the U-pin in a latched position. Release the latch spring upon reaching a predetermined rotational position of the knob, allowing the trip latch to continue a clockwise rotation propelled by the main spring. Establish contact between the moving contact and the fixed contact upon reaching the predetermined rotational position of the knob. Establish contact pressure between the moving contact and the fixed contact facilitated by the force applied by the main spring and toggle U-pin, upon an additional rotation of the knob, obtaining a closed position and securely connecting the MCB.
[0016] In another aspect, at the trip state, the MCB is configured to activate a short-circuit release mechanism in response to a short circuit, the short-circuit release mechanism comprising a hammer. Induce an anti-clockwise rotation of the trip latch during activation, thereby causing disengagement of the U-pin from the latch portion due to the unique profile, allowing the U-pin to move into the groove of the contact holder and create space for the U-pin to disengage from the latch portion and move into the groove of the contact holder through a pin holding portion of the trip latch, wherein the pivotal shift of the kinematic pin is generated that separates the fixed contact and the moving contact, facilitated by a clockwise movement of the knob driven by the knob spring.
[0017] In another aspect, the actuating mechanism includes a bimetallic strip that induces an anti-clockwise rotation of the trip latch during an overload release. The actuating mechanism includes a pin holding portion on the trip latch configured with a specific angle, wherein, the specific angle on the pin holding portion and the protrusion on the knob collectively act to drive the U-pin into a fully open position during the tripped condition. The specific angle on the pin holding portion of the trip latch and the protrusion on the knob contribute to the secure latching of the actuating mechanism during close operations.
[0018] In another aspect, the trip latch performs the roles of two separate latches and emphasizes the inclusion of a specific surface finish tailored to ensure the efficient re-setting of these latches. The contact holder integrates diverse operations into a singular component, simplifying the structure and enhancing the operational efficiency of the actuation mechanism, wherein the diverse operations of the contact holder include a set of latching components for securing the MCB in a closed position. Serving as a guide facilitating the movement of the U-Pin during various operational phases, serving as a base link providing structural support for the actuation mechanism and functioning as a main spring anchor within the mechanism.
[0019] 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
[0020] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0021] FIG. 1A illustrates an exemplary view of the open position of actuating mechanism, in accordance with an embodiment of the present disclosure.
[0022] FIG. 1B illustrates an exemplary view of the closed position of actuating mechanism, in accordance with an embodiment of the present disclosure.
[0023] FIG. 1C illustrates an exemplary view of the tipped position of actuating mechanism, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0024] 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. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0025] 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.
[0026] The present disclosure relates, in general, to a miniature circuit breaker (MCB), and more specifically, relates to an optimized actuating mechanism for a miniature circuit breaker with a reduced number of components.
[0027] The present disclosure relates to an actuating mechanism of a miniature circuit breaker (MCB). The actuating mechanism includes a knob that is pivotally mounted in a housing to facilitate rotational operation for switching the MCB to close, open and trip states. A contact holder securely fastened to a moving contact, both pivotally mounted on a kinematic pin within the housing to enable controlled movement of the MCB. A U-pin is pivotally mounted at one end within the knob and securely latched onto a latch portion of the contact holder at the other end, the U-pin is responsive to the rotational movement of the knob with the U-pin located between the latch portion and a trip latch, wherein the latch portion incorporates a unique profile that enables the U-pin to transfer force on the trip latch after the predefined rotation of the knob, eliminating additional components to guide the U-pin and eliminating special finish requirements for gliding surfaces of latches. A groove accommodated on the contact holder constrains the movement of the U-pin in trip condition. A knob spring exerts a force on the knob and transfers to the U-pin through a protrusion, wherein a middle position of the knob serves as an indicator for the tripped state of contacts, obtained through the manipulation of the knob spring. A fixed contact affixed to the housing to establish a stable point of contact with the moving contact to ensure reliable and proper electrical connectivity, wherein the rotational operation of the knob configured to facilitate switching the MCB to the close state allowing the moving contact to establish contact with the fixed contact, facilitate switching the MCB to the open state causing the moving contact to separate from the fixed contact and facilitate switching the MCB to the trip state causing the moving contact to separate from the fixed contact.
[0028] In an aspect, at the open state, the MCB is configured to initiate the U-pin toggling through rotation of the knob. Exert force on the knob by the knob spring to pull the U-pin. Initiate pivotal shift by the kinematic pin when the moving contact and the fixed contact begin to separate disrupting an electrical connection and apply force on the contact holder and the fixed contact by the main spring in opposite directions, generating a torque for accelerated opening of the moving contact and the fixed contact. The predefined rotation of the knob is determined by the MCB specifications for optimal contact performance.
[0029] In another aspect, at the close state, the MCB is configured to exert pressure on the U-pin in response to the rotational movement of the knob. Push the contact holder away from the latch portion against the main spring as a result of the pressure applied to the U-pin. Facilitate a pivotal movement of the moving contact and the fixed contact during the closing operation along an axis defined by the kinematic pin. Employ the latch spring to exert force on the trip latch during a closing operation, maintaining the U-pin in a latched position. Release the latch spring upon reaching a predetermined rotational position of the knob, allowing the trip latch to continue a clockwise rotation propelled by the main spring. Establish contact between the moving contact and the fixed contact upon reaching the predetermined rotational position of the knob. Establish contact pressure between the moving contact and the fixed contact facilitated by the force applied by the main spring and toggle U-pin, upon an additional rotation of the knob, obtaining a closed position and securely connecting the MCB.
[0030] In another aspect, at the trip state, the MCB is configured to activate a short-circuit release mechanism in response to a short circuit, the short-circuit release mechanism comprising a hammer. Induce an anti-clockwise rotation of the trip latch during activation, thereby causing disengagement of the U-pin from the latch portion due to the unique profile, allowing the U-pin to move into the groove of the contact holder and create space for the U-pin to disengage from the latch portion and move into the groove of the contact holder through a pin holding portion of the trip latch, wherein the pivotal shift of the kinematic pin is generated that separates the fixed contact and the moving contact, facilitated by a clockwise movement of the knob driven by the knob spring.
[0031] In another aspect, the actuating mechanism includes a bimetallic strip that induces an anti-clockwise rotation of the trip latch during an overload release. The actuating mechanism includes a pin holding portion on the trip latch configured with a specific angle, wherein, the specific angle on the pin holding portion and the protrusion on the knob collectively act to drive the U-pin into a fully open position during the tripped condition. The specific angle on the pin holding portion of the trip latch and the protrusion on the knob contribute to the secure latching of the actuating mechanism during close operations.
[0032] In another aspect, the trip latch performs the roles of two separate latches and emphasizes the inclusion of a specific surface finish tailored to ensure the efficient re-setting of these latches. The contact holder integrates diverse operations into a singular component, simplifying the structure and enhancing the operational efficiency of the actuation mechanism, wherein the diverse operations of the contact holder include a set of latching components for securing the MCB in a closed position. Serving as a guide facilitating the movement of the U-Pin during various operational phases, serving as a base link providing structural support for the actuation mechanism and functioning as a main spring anchor within the mechanism. The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure.
[0033] The advantages achieved by the actuation mechanism of the present disclosure can be clear from the embodiments provided herein. The MCB actuation mechanism is characterized by a reduced number of components, strategically designed with considerations for both design for manufacturability (DFM) and design for assembly (DFA). This deliberate approach not only results in a significant reduction in component costs but also leads to more economical assembly processes. The mechanism not only lowers manufacturing costs but also facilitates easier maintenance. By streamlining component costs, simplifying assembly procedures, and optimizing manufacturing efficiency, the present disclosure ensures that these cost savings can be transferred to end-users, making the MCB actuation mechanism a more economically viable solution for customers. Furthermore, the incorporation of fewer components in the mechanism enhances its overall quality and consistency, aligning with industry standards and contributing to a reliable and efficient MCB actuation system. The description of terms and features related to the present disclosure shall be clear from the embodiments that are illustrated and described; however, the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents of the embodiments are possible within the scope of the present disclosure. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to the following description.
[0034] FIG. 1A illustrates an exemplary view of the open position of actuating mechanism, in accordance with an embodiment of the present disclosure.
[0035] Referring to FIG. 1A, the optimized actuating mechanism 100 for a miniature circuit breaker (MCB) includes a short-circuit release and thermal release for protection against short-circuit fault and overload fault respectively. The actuating mechanism 100 can include a housing 102, knob 104, U-pin 106, contact holder 108, moving contact 110, kinematic pin 112, fixed contact 114, trip latch 116, main spring 118, latch spring 120, knob spring 122, latch portion 124, groove 126, protrusion 128 on the knob 104, pin holding portion 130, hammer 132, and bimetallic strip 134.
[0036] The actuating mechanism 100 of the MCB can incorporate the housing 102, where an actuator or knob 104 is pivotally mounted, facilitating manual control for the purpose of switching the MCB on, off and trip positions. The contact holder 108 and moving contact 110 are securely fastened together, ensuring that their relative motion is constrained. The assembly of the contact holder 108 and moving contact 110 is pivotally mounted on the kinematic pin 112, which is fixed within the housing 102, allowing controlled movement essential for the proper functioning of the MCB.
[0037] The contact holder 108 securely holds and positions the moving contact 110, providing stability and a fixed reference point for controlled electrical contacts within the MCB. The moving contact 110 is responsible for establishing or breaking the electrical connection within the MCB. It moves in relation to the fixed contact 114, allowing the circuit to open or close based on the operational state of the MCB. The kinematic pin 112 serves as a pivot point for the assembly of contact holder 108 and moving contact 110. It enables controlled and constrained motion, allowing the contacts to open or close in response to the manual or automatic operation of the MCB, ensuring proper electrical circuit protection.
[0038] The U-pin 106, pivotally mounted within the knob 104, is latched at its second end onto the contact holder latch portion 124. Positioned between the trip latch 116 and contact holder latch portion 124, the U-Pin 106 is secured with the assistance of the latch spring 120. Meanwhile, a dual-purpose main spring 118 serves as both a return spring and a contact pressure spring, positioned between the contact holder 108 and the housing 102. The fixed contact 114 is affixed to the housing 102, completing the assembly with the specified functions of latching, trapping, and providing spring-based functions for the proper operation of the miniature circuit breaker.
[0039] The U-pin 106 is a pivotal element within the knob 104 enabling controlled movement. It is latched onto the contact holder latch portion 124. The fixed contact 114, affixed to the housing 102, serves as a stationary element in the circuit, ensuring a stable point of contact with the moving contact 110 for proper electrical connectivity. Together, these components contribute to the efficient latching, trapping, and spring-based functions essential for the reliable operation of the MCB.
[0040] During the opening operation of the MCB shown in FIG. 1A, rotation of the knob 104 initiates the toggling of the U-Pin 106 to the opposite side, compelling the knob spring 122 to exert force on the knob 104 and pull the U-pin 106. Upon reaching a predefined position of knob 104 rotation, when moving contact 110 and fixed contact 114 begin to separate or open, the pivot shifts back to the kinematic pin 112. At this critical moment, the main spring 118 applies force on the contact holder 108 and the fixed contact 114 on opposite sides of the pivot, generating a torque or couple and facilitating faster opening of the contacts.
[0041] For example, in the initiation of the opening operation, rotation of the knob 104 serves as the user-initiated action to deactivate the MCB. This rotation induces the toggling motion of the U-Pin (106) to the opposite side, resembling a toggle switch changing positions. The movement of the U-pin triggers the knob spring 122, exerting force on the knob 104. Upon reaching a predefined position during knob rotation, the moving contact 110 and fixed contact 114 within the MCB begin to separate, disrupting the electrical connection. Simultaneously, the pivot point shifts back to the kinematic pin 112, a pivotal moment in the mechanism. Subsequently, the main spring 118 engages, applying force on the contact holder 108 and the fixed contact 114 on opposing sides of the pivot, generating a mechanical couple. This mechanical couple facilitates a rapid and efficient opening of the contacts, ensuring a swift interruption of the electrical circuit.
[0042] The mechanism in an open (OFF) condition, the illustration showcases the arrangement of key components and their respective assembly positions. These components have been subject to modifications aligned with the principles of Design for Manufacturing (DFM) and Design for Assembly (DFA), strategically implemented to streamline the manufacturing and assembly processes. The resultant assembly has been optimized for automation, thereby contributing to a reduction in manufacturing and assembly costs and, consequently, an overall decrease in the total mechanism cost.
[0043] FIG. 1B illustrates an exemplary view of closed position of actuating mechanism, in accordance with an embodiment of the present disclosure. During the closing operation of the MCB as shown in FIG. 1B, when the knob 104 is rotated, the knob 104 exerts pressure on the U-Pin 106, subsequently pushing the contact holder 108 away from the latch portion 124 against the main spring 118. Simultaneously, the contact holder 108 and the moving contact 110 pivot along the axis of the kinematic pin 112. The force applied by the latch spring 120 causes the trip latch 116 to rotate, holding the U-Pin 106 in a latched position.
[0044] As the knob 104 continues its predefined rotation, the latch spring 120 disengages, ceasing to apply force on the trip latch 116. However, due to the moment created by friction between the trip latch 116 and U-Pin 106, propelled by the main spring 118, the trip latch 116 continues to rotate in a clockwise direction. Once the knob 104 reaches its predetermined rotational position, the moving contact 110 and fixed contact 114 make contact, and the pivot shifts from the kinematic pin 112 to the contact holder latch portion 124.
[0045] At this moment, the main spring 118 applies force on the moving contact 110 and the contact holder 108 on one side of the pivot. This force establishes contact pressure between the moving contact 110 and the fixed contact 114. After an additional predefined rotation of the Knob 104, the U-Pin 106 toggles, achieving the ON or closed position of the MCB. This sequence of actions ensures a controlled and reliable closure of the circuit within the MCB.
[0046] For example, in the closing operation of the MCB, a method includes rotating the knob 104 to initiate closure, wherein the knob applies pressure on the U-Pin 106, prompting the movement of the contact holder 108 away from the latch portion 124 against the main spring (118). Concurrently, the contact holder and the moving contact 110 pivot about the kinematic pin 112. Subsequently, the latch spring 120 engages, causing rotation of the trip latch 116 and securing the U-Pin 106. Further rotation of the knob disengages the latch spring, allowing the trip latch to continue rotating due to the moment created by friction and main spring propulsion. Upon reaching a predetermined knob rotational position, contact occurs between the moving contact 110 and the fixed contact 114, accompanied by a pivotal shift from the kinematic pin to the contact holder latch portion (124). The main spring (118) applies force, establishing contact pressure between the moving contact and the fixed contact. Following an additional knob rotation, the U-Pin toggles, achieving the ON or closed position, thereby securely connecting the electrical circuit.
[0047] In the closed (ON) condition, the circuit breaker actuating mechanism, as illustrated in FIG. 1B, is characterized by the physical contact between both the moving contact and fixed contact, the complete compression of the main spring 118 to its predetermined final position, the latch spring 120 lifted from its loaded position, and the trip latch 116 being free from any spring loading.
[0048] FIG. 1C illustrates an exemplary view of tipped position of actuating mechanism, in accordance with an embodiment of the present disclosure. The present disclosure relates a tripping mechanism that includes a short-circuit release and an overload release. In the event of a short circuit, activation of the short-circuit release causes the hammer 132 to impact the trip latch 116, inducing an anti-clockwise rotation. This rotation disengages the U-Pin 106 from the contact holder latch portion 124 due to the unique profile, allowing it to move into the groove 126 of contact holder 108. The pin holding portion 130 of trip latch 116 may create space for the U-Pin 106 to disengage from contact holder latch portion 124 due to unique profile of same and may move into groove 126 of contact holder 108. The resulting pivot shift separates the contacts, facilitated by the clockwise movement of knob 104 driven by the knob spring.
[0049] Subsequent resetting involves the knob 104 spring pulling the U-Pin 106 back to its initial position, aided by the trip latch 116 rotating slightly anti-clockwise to allow re-engagement with the contact holder latch portion 124 with a force from protrusion 128 given on the knob 104 and unique angle provided on pin holding portion 130 of trip latch 116.
[0050] A similar tripping process occurs during an overload release, where the bimetallic strip 134 induces an anti-clockwise rotation of the trip latch 116.
[0051] In the tripped condition of the mechanism, both the fixed and movable contacts are visibly separated, and U-Pin 106 is precisely guided within the groove 126 of the contact holder 108. The knob spring exerts force on the knob 104, subsequently pulling the U-Pin 106 within the groove 126. The specific angle incorporated on the pin holding portion 130 of the trip latch 116 and the protrusion 128 on the knob 104 collectively act to drive the U-Pin 106 into a fully open (OFF) position. This configuration ensures that during subsequent close operations (ON), the mechanism remains in a securely latched position.
[0052] Thus, the present invention overcomes the drawbacks, shortcomings, and limitations associated with existing solutions, and provides the MCB actuation mechanism characterized by a reduced number of components, strategically designed with considerations for both design for manufacturability (DFM) and design for assembly (DFA). This deliberate approach not only results in a significant reduction in component costs but also leads to more economical assembly processes. The mechanism not only lowers manufacturing costs but also facilitates easier maintenance. By streamlining component costs, simplifying assembly procedures, and optimizing manufacturing efficiency, the present invention ensures that these cost savings can be transferred to end-users, making the MCB actuation mechanism a more economically viable solution for customers. Furthermore, the incorporation of fewer components in the mechanism enhances its overall quality and consistency, aligning with industry standards and contributing to a reliable and efficient MCB actuation system.
[0053] It will be apparent to those skilled in the art that the actuation mechanism 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT INVENTION
[0054] The present invention provides a mechanism in which the utilization of a reduced number of components in the MCB actuation mechanism, coupled with design considerations for design for manufacturability (DFM) and design for assembly (DFA), leads to a significant reduction in both component costs and assembly expenses.
[0055] The present invention provides a mechanism that reduces manufacturing costs and also contributes to easier maintenance.
[0056] The present invention provides a mechanism that is realized through reduced component costs, simplified assembly, and efficient manufacturing that can be passed on to customers, making the MCB actuation mechanism more cost-effective for end-users.
[0057] The present invention provides a mechanism with fewer components that enhances the quality and consistency of the MCB actuation mechanism.
, Claims:1. An actuating mechanism (100) of a miniature circuit breaker (MCB), the actuating mechanism comprising:
a knob (104) pivotally mounted in a housing (102) to facilitate rotational operation for switching the MCB to close, open and trip states;
a contact holder (108) securely fastened to a moving contact (110), both pivotally mounted on a kinematic pin (112) within the housing (102) to enable controlled movement of the MCB;
a U-pin (106) is pivotally mounted at one end within the knob (104) and securely latched onto a latch portion (124) of the contact holder (108) at other end, the U-pin responsive to the rotational movement of the knob with the U-pin (106) located between the latch portion (124) and a trip latch (116) through a latch spring (120), wherein the latch portion (124) incorporates a unique profile enables the U-pin (106) to transfer force on the trip latch (116) after a predefined rotation of the knob, eliminating additional components to guide the U-pin (106) and eliminating special finish requirements for gliding surfaces of latches;
a groove (126) accommodated on the contact holder (108) to constrain movement of the U-pin (106) in trip condition;
a knob spring (122) exerts a force on the knob (104) and transfers to the U-pin (106) through a protrusion (128), wherein a middle position of the knob (104) serves as an indicator for a tripped state of contacts, obtained through manipulation of the knob spring (122); and
a fixed contact (114) affixed to the housing (102) to establish a stable point of contact with the moving contact (110) to ensure reliable and proper electrical connectivity, wherein the rotational operation of the knob (104) configured to:
facilitate switching the MCB to the close state allowing the moving contact (110) to establish contact with the fixed contact (114);
facilitate switching the MCB to the open state causing the moving contact (110) to separate from the fixed contact (114); and
facilitate switching the MCB to the trip state causing the moving contact (110) to separate from the fixed contact (114).
2. The actuating mechanism as claimed in claim 1, wherein, at the open state, the MCB is configured to:
initiate the U-pin (106) toggling through rotation of the knob (104);
exert force on the knob (104) by the knob spring (122) to pull the U-pin (106);
initiate pivotal shift by the kinematic pin (112) when the moving contact (110) and the fixed contact (114) begin to separate disrupting an electrical connection; and
apply force on the contact holder (108) and the fixed contact (114) by a main spring (118) in opposite directions, generating torque for accelerated opening of the moving contact (110) and the fixed contact (114).
3. The actuating mechanism as claimed in claim 1, wherein the predefined rotation of the knob (104) is determined by the MCB specifications for optimal contact performance.
4. The actuating mechanism as claimed in claim 1, wherein at the close state, the MCB is configured to:
exert pressure on the U-pin (106) in response to the rotational movement of the knob (104);
push the contact holder (108) away from the latch portion (124) against the main spring (118) as a result of the pressure applied to the U-pin (106);
facilitate a pivotal movement of the moving contact (110) and the fixed contact (114) during a closing operation along an axis defined by the kinematic pin (112);
employ the latch spring (120) to exert force on the trip latch (116) during the closing operation, maintaining the U-Pin (106) in a latched position;
release the latch spring (120) upon reaching a predetermined rotational position of the knob (104), allowing the trip latch (116) to continue clockwise rotation propelled by the main spring (118);
establish contact between the moving contact (110) and the fixed contact (114) upon reaching the predetermined rotational position of the knob (104);
establish contact pressure between the moving contact (110) and the fixed contact (114) facilitated by the force applied by the main spring (118); and
toggle the U-pin (106), upon an additional rotation of the knob (104), obtaining a closed position and securely connecting the MCB.
5. The actuating mechanism as claimed in claim 1, wherein at the trip state, the MCB is configured to:
activate a short-circuit release mechanism in response to a short circuit, the short-circuit release mechanism comprising a hammer (132);
induce an anti-clockwise rotation of the trip latch (116) during activation, thereby causing disengagement of the U-pin (106) from the latch portion (124) due to the unique profile, allowing the U-pin (106) to move into the groove (126) of the contact holder (108); and
create space for the U-pin (106) to disengage from the latch portion (124) and move into the groove (126) of the contact holder (108) through a pin holding portion (130) of the trip latch (116), wherein the pivotal shift of the kinematic pin is generated that separates the fixed contact and the moving contact, facilitated by a clockwise movement of the knob (104) driven by the knob spring (122).
6. The actuating mechanism as claimed in claim 1, wherein the actuating mechanism comprises a bimetallic strip (134) that induces an anti-clockwise rotation of the trip latch (116) during an overload release.
7. The actuating mechanism as claimed in claim 1, wherein the actuating mechanism configured to:
establish the pin holding portion (130) on the trip latch (116) with a specific angle, wherein, the specific angle on the pin holding portion (130) and the protrusion (128) on the knob (104) collectively act to drive the U-pin (106) into a fully open position during the tripped condition.
8. The actuating mechanism as claimed in claim 1, wherein the specific angle on the pin holding portion (130) of the trip latch (116) and the protrusion (128) on the knob (104) contribute to the secure latching of the actuating mechanism during close operations.
9. The actuating mechanism as claimed in claim 1, wherein the trip latch (116) performs the roles of two separate latches and emphasizes inclusion of a specific surface finish tailored to ensure the efficient re-setting of these latches.
10. The actuating mechanism as claimed in claim 1, wherein the contact holder (108) integrates diverse operations into a singular component, simplifying the structure and enhancing operational efficiency of the actuation mechanism, wherein the diverse operations of the contact holder comprise:
a set of latching components configured to secure the MCB in the closed position.;
serving as a guide facilitating the movement of the U-pin (106) throughout different operational phases;
serving as a base link providing structural support for the actuation mechanism; and
function as a main spring anchor within the mechanism, ensuring stability and controlled energy release.