EP4597537A1

EP4597537A1 - Tripping mechanism of circuit breaker, and circuit breaker

Info

Publication number: EP4597537A1
Application number: EP23870533.9A
Authority: EP
Inventors: Min Chen; Yongshuai JIA; Xieli ZHANG; Yanhai Zhou; Senlin LAI; Guanshang SUN
Original assignee: Xiamen Hongfa Automotive Electronics Co Ltd
Current assignee: Xiamen Hongfa Automotive Electronics Co Ltd
Priority date: 2022-09-29
Filing date: 2023-09-20
Publication date: 2025-08-06
Also published as: WO2024067301A1

Abstract

A tripping mechanism of a circuit breaker, and a circuit breaker. The tripping mechanism comprises a jump pin (17), a re-buckle (18) and a lock latch (20), which are rotatably arranged, wherein the re-buckle (18) is of a labor-saving lever structure and comprises a first lever arm (181) and a second lever arm 182); a first lap joint portion (1703) is arranged on the jump pin (17), a first press-fitting portion (1801) is correspondingly provided on the first lever arm (181); and a second lap joint portion (1803) is provided on the second lever arm ( 182), and a second press-fitting portion (2001) is correspondingly provided on the lock latch (20). The relative positions of the jump pin (17), the re-buckle (18) and the lock latch (20) are configured in such a way that, by means of relative rotation between each other, the first press-fitting portion (1801) is press-fitted to the first lap joint portion (1703) while the second press-fitting portion (2001) is press-fitted to the second lap joint portion (1803), thus the rotation of the jump pin (17) is limited, a first rotating force arm (L1) of the first press-fitting portion (1801) being smaller than a second rotating force arm (L2) of the second lap joint portion (1803).

Description

CROSS-REFERENCE

This disclosure claims priority to Chinese Patent Applications No. 202211200068.5 , titled "Trip Mechanism of Circuit Breaker and Circuit Breaker", and No. 202211200055.8, titled "Circuit Breaker and Combination Switching Electrical Apparatus", both filed on September 29, 2022 , the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of circuit breaker manufacturing technology, and more specifically, to improvements to a trip mechanism and a circuit breaker having such trip mechanism.

BACKGROUND

A trip mechanism is common mechanism in circuit breakers, designed to rapidly disconnect circuits during abnormal conditions by triggering quick movement of the movable contact through the action of the trip latch. Conventional trip mechanisms typically consist of only a trip latch and locking catch. The trip latch is mechanically linked to the movable contact and engages with the locking catch to maintain a locked state. The locking catch is also engaged with a trip actuator; when the trip actuator acts on the locking catch, the action of the lock catch releases the locking state of the trip latch and locking catch, which leads to the quick action of the trip latch.
However, due to space constraints within circuit breakers, trip latches are generally small (short) in size, resulting in short force arms. With constant torque, shorter force arms require greater force application from the trip latch to the locking catch, consequently demanding higher locking and unlocking forces. The push force and push distance of the push rod of the trip actuators (e.g., electromagnetic type trip actuators) commonly used in related technologies are both small, so the tripping force required by the lock catch is too large, and the push force of the trip actuator may not push the trip mechanism to trip, and when an abnormal situation occurs in the circuit, the quick disconnection between contacts cannot be guaranteed.

SUMMARY

Therefore, in view of the above problems, according to one aspect of the present disclosure, a trip mechanism for a circuit breaker with optimized structure and a circuit breaker having the trip mechanism are proposed.
The technical solutions of the disclosure include:
A trip mechanism for a circuit breaker comprises a rotatably mounted trip latch, a reset lever and a locking catch, wherein the reset lever is configured as a force-reducing lever structure comprising a first lever arm and a second lever arm, the trip latch is provided with a first engagement portion, the first lever arm is correspondingly provided with a first pressing portion, the second lever arm is provided with a second engagement portion, and the locking catch is correspondingly provided with a second pressing portion. Wherein the relative positions of the trip latch, reset lever and locking catch are configured such that through their relative rotation, the second pressing portion engages with the second engagement portion while the first pressing portion simultaneously mates with the first engagement portion, so as to restrict rotation of the trip latch, wherein a first torque arm of the first pressing portion is shorter than a second torque arm of the second engagement portion.
In some embodiments, the first lever arm and second lever arm rotate together about a rotation axis of the reset lever, and the first lever arm and second lever arm protrude in a same direction with different heights, or the first lever arm and second lever arm form an acute angle and present a V-shape.
In some embodiments, rotation centers of the reset lever and locking catch are respectively positioned at two sides of a rotation center of the trip latch, such that the second lever arm extends from one side to another side of the rotation center of the trip latch.
In some embodiments, the trip latch is configured as a swing arm structure, the first engagement portion is disposed at a terminal end of the trip latch, and the second engagement portion is disposed at a terminal end of the second lever arm.
In some embodiments, the locking catch is provided with a protrusion abutting against the terminal end of the second lever arm, and an overlapping amount between the second engagement portion and second pressing portion is controlled by modifying a height of the protrusion.
Embodiments of the present disclosure further provide a circuit breaker, which comprise an operating mechanism, a contact assembly comprising a movable contact and a stationary contact, wherein the movable contact is mechanically linked to the operating mechanism and has a movable stroke relative to the stationary contact to realize the connection or disconnection of the circuit breaker, the circuit breaker further comprises a trip mechanism for circuit breaker tripping, and a trip actuator for triggering the trip mechanism, wherein the trip mechanism is according to any one of claims 1-5, the trip latch is mechanically linked to the operating mechanism, and the trip actuator is configured to drive the locking catch to move.
In some embodiments, taking length direction of the circuit breaker as front-rear direction and height direction as up-down direction, the operating mechanism and contact assembly are substantially arranged along the up-down direction, the trip mechanism is substantially arranged along the front-rear direction, thereby forming a cross-shaped layout.
In some embodiments, the reset lever is hinged at a rear side of the trip latch; the locking catch is hinged at a front side of the trip latch, such that the second lever arm extends from rear to front.
In some embodiments, further comprising a movable contact support, wherein the movable contact is mounted on the movable contact support and moves along with the movable contact support, the reset lever is hinged at a direct rear side of the trip latch, the locking catch is arranged in an upper diagonal direction of a front side of the trip latch, such that the second lever arm extends obliquely upward, and the locking catch and movable contact support form an up-down arrangement.
In some embodiments, the operating mechanism comprises a handle rotatably mounted above the reset lever, and a disk-shaped connection base for mounting the handle, the reset lever is configured as a curved extension matching the contour of the connection base.
In some embodiments, taking a width direction of the circuit breaker as left-right direction, the first pressing portion and second engagement portion of the reset lever are offset in left-right direction, and the trip latch cooperating with the first pressing portion and the locking catch cooperating with the second engagement portion are also offset in left-right direction and not coplanar.
In some embodiments, the operating mechanism comprises a rotatable handle having two resting positions as open position and closed position, the handle is mechanically linked to both the trip latch and movable contact through a linkage mechanism, the linkage mechanism transmits force to the trip latch such that when the handle swings from the open position to the closed position, the handle pulls the first engagement portion of the trip latch against the first pressing portion, and indirectly pushes the second engagement portion against the second pressing portion, so as to lock the trip mechanism.
In some embodiments, the handle, the reset lever and the locking catch are respectively provided with a first elastic member providing elastic force to rotate the handle toward open position and indirectly reset the trip latch, a second elastic member providing reset force for the reset lever, and a third elastic member providing reset force for the locking catch.
In some embodiments, taking height direction of the circuit breaker as up-down direction, the second engagement portion is positioned above a rotation axis of the locking catch, a clearance notch is provided below the second pressing portion to allow reset travel of the reset lever.
In some embodiments, the circuit breaker further comprises a first stopper fixed on a reset paths of the trip latch and reset lever to limit positions of the trip latch and reset lever.
In some embodiments, the trip latch can reset prior to the reset lever, and the reset lever can reset prior to the locking catch.
In some embodiments, one end of the reset lever in a reset movement direction is provided with a first limit surface, the trip latch has a first stopping portion that abuts the first limit surface to block the reset lever reset, a first termination end is provided on the first limit surface along a reset direction of the trip latch, such that after the first stopping portion passes the first termination end, the first stopping portion disengages from the first limit surface, allowing the trip latch to reset prior to the reset lever
In some embodiments, one end of the locking catch in a reset movement direction is provided with a second limit surface, the reset lever has a second stopping portion that abuts the second limit surface to block locking catch reset, a second termination end is provided on the second limit surface along a reset direction of the reset lever, such that when the second stopping portion passes the second termination end, the second stopping portion disengages from the second limit surface, allowing the reset lever to reset prior to the locking catch.
The embodiments of the present disclosure have the following beneficial effects: In the present disclosure, the reset lever is added to the trip mechanism, such that in the trip mechanism, the locking catch first locks the reset lever, and then the reset lever locks the trip latch. Since the reset lever is a force-reducing lever structure, the force applied by the trip latch to the locking catch through the force-reducing lever structure is smaller. Therefore, the release force required by the electromagnetic trip actuator to unlock the locking catch is also reduced, ensuring that the contacts can automatically disconnect in the event of a leakage fault.
According to another aspect of the present disclosure, a circuit breaker is provided, comprising a trip mechanism for realizing trip opening. The trip mechanism comprises a trip latch, and the circuit breaker further comprises an external accessory linkage mechanism. The external accessory linkage mechanism comprises a first linkage member and a second linkage member. The first linkage member is coaxially connected to the trip latch and can operate in conjunction therewith. The second linkage member is movably arranged at a side of the first linkage member and can be pushed by the first linkage member when the trip latch is released. The second linkage member is provided with a coupling connection portion for coupling with an external accessory, such that one of the second linkage member and the external accessory can drive the another to move.
In some embodiments, the trip mechanism further comprises a locking catch for locking or unlocking the trip latch. The circuit breaker further comprises a third linkage member movably arranged at a side of the second linkage member and can be pushed by the second linkage member to move. The locking catch is provided with an actuating portion extending to a side of the third linkage member away from the second linkage member, such that when the second linkage member pushes the third linkage member, the second linkage member can further actuate the actuating portion to unlock the locking of the trip latch by the locking catch, thereby causing trip opening.
In some embodiments, the external accessory comprises a coupling cooperation portion for coupling with the coupling connection portion. The external accessory is a passive-triggered accessory triggered by the first linkage member pushing the second linkage member to actuate the coupling cooperation portion, or an active-driven accessory that actively drives the second linkage member through the coupling cooperation portion.
In some embodiments, one of the coupling connection portion and the coupling cooperation portion is a hole, and the other is a rod inserted into the hole.
In some embodiments, the coupling connection portion is a hole, the coupling cooperation portion is a rod inserted into the hole, and a diameter of the hole is larger than a diameter of the rod.
In some embodiments, opposite sides of the second linkage member and the third linkage member are each provided with a first protrusion and a second protrusion protruding toward and approaching each other.
In some embodiments, the circuit breaker further comprises a movable contact support for driving the movable contact. The third linkage member is a swing arm structure. A first end of the third linkage member is rotatably connected to the movable contact support, and a second end of the third linkage member is against a stationary contact point under the action of an elastic member in a direction away from the actuating portion.
In some embodiments, the relative positions of the second linkage member, the third linkage member, and the movable contact support are configured such that, the movable contact support can drive the first end of the third linkage member to deflect away from the second linkage member during opening, to escape from a stroke range of the second linkage member.
In some embodiments, the opposing sides of the second linkage member and third linkage member are each provided with a first protruding portion and second protruding portion protruding toward and approaching each other, wherein the first protruding portion and second protruding portion have tapered pointed shapes that gradually narrow toward their front ends respectively, so that when the movable contact support opens, the second protruding portion can quickly disengage from the travel range of the first protruding portion.
In some embodiments, the circuit breaker further includes an indicator member for indicating a status of the circuit breaker, wherein the indicator member is a lever structure with one end rotatably connected to the movable contact support, and the stationary contact point is a shaft of the indicator member.
In some embodiments, the second linkage member is a rotatably mounted swing arm, and a limit post is fixed at a side of the second linkage member near a movement direction of the first linkage member, to limit an extreme swinging position of the second linkage member toward the first linkage member.
In some embodiments, the circuit breaker further includes a mounting base, wherein the mounting base includes a first side plate and second side plate that are assembled opposite each other, the trip mechanism is disposed between the first side plate and second side plate, and the external accessory linkage mechanism is mounted on an outer side surface of the first side plate, so that the external accessory linkage mechanism and trip mechanism are at different installation lays.
Based on the above circuit breaker, the present disclosure further provides a combined switching electrical apparatus, including the circuit breaker according to any of the preceding embodiments and an external accessory coupled to the circuit breaker.
The present disclosure has the following beneficial effects: by providing the external accessory linkage mechanism, the circuit breaker can modularly connect with external accessories, and one set of external accessory linkage mechanism in the embodiments of the present disclosure can be optionally engaged with multiple different external accessories, greatly improving the flexibility of installing external accessories on the circuit breaker.

BRIEF DESCRIPTION OF THE DRAWINGSS

FIG. 1 is a schematic overall view of a circuit breaker according to some embodiments of the present disclosure.
FIG. 2 is an exploded structural view of the circuit breaker according to some embodiments.
FIG. 3 is a perspective view of the circuit breaker (with upper cover removed) according to some embodiments.
FIG. 4 is a schematic diagram of the conductive system, operating mechanism, and trip mechanism of the circuit breaker (closed state) according to some embodiments.
FIG. 5 is an exploded structural view of an operating linkage assembly according to some embodiments.
FIG. 6 is a perspective view of a first side plate according to some embodiments.
FIG. 7 is a perspective view (angle 1) of a second side plate according to some embodiments.
FIG. 8 is a perspective view of a handle according to some embodiments.
FIG. 9 is a schematic view of a second link according to some embodiments.
FIG. 10 is a schematic view of a third link according to some embodiments.
FIG. 11 is a schematic view of a movable contact support according to some embodiments.
FIG. 12 is a perspective view of a trip latch according to some embodiments.
FIG. 13 is a perspective view (angle 1) of a locking catch according to some embodiments.
FIG. 14 is a perspective view (angle 2) of the locking catch according to some embodiments.
FIG. 15 is a perspective view of a reset lever according to some embodiments.
FIG. 16 is a schematic diagram of the cooperation between the reset lever and locking catch according to some embodiments.
FIG. 17 is a schematic diagram of the conductive system, operating mechanism, and trip mechanism (manual opening state) according to some embodiments.
FIG. 18 is a schematic diagram of the conductive system, operating mechanism, and trip mechanism (tripped state) according to some embodiments.
FIG. 19 is a schematic diagram of cooperation among an electromagnetic trip actuator, linkage member, and locking catch according to some embodiments.
FIG. 20 is a perspective view of the linkage member according to some embodiments.
FIG. 21 is a perspective view (angle 2) of the second side plate according to some embodiments.
FIG. 22 is a schematic diagram of cooperation between a first limit surface of the reset lever and a first stopping portion of the trip latch according to some embodiments.
FIG. 23 is a schematic diagram of cooperation between a second limit surface of the locking catch and a second stopping portion of the reset lever according to some embodiments.
FIG. 24 is a schematic diagram showing offset arrangement in left-right direction between a first pressing portion, trip latch and a second engagement portion, locking catch according to some embodiments.
FIG. 25 is a top view of the reset lever according to some embodiments.
FIG. 26 is a schematic overall view of the circuit breaker according to some embodiments.
FIG. 27 is an exploded structural view of the circuit breaker according to some embodiments.
FIG. 28 is a perspective view of the circuit breaker (with upper cover removed) according to some embodiments.
FIG. 29 is a schematic diagram of the conductive system, operating mechanism, and trip mechanism according to some embodiments.
FIG. 30 is an exploded structural view of the operating linkage assembly according to some embodiments.
FIG. 31 is a schematic diagram of an external accessory linkage mechanism assembled on the circuit breaker (closed state) according to some embodiments.
FIG. 32 is a perspective view of the first side plate according to some embodiments.
FIG. 33 is a schematic view of a first linkage member according to some embodiments.
FIG. 34 is a schematic view of a second linkage member according to some embodiments.
FIG. 35 is a schematic view of a third linkage member according to some embodiments.
FIG. 36 is a schematic view of an indicator member according to some embodiments.
FIG. 37 is a schematic diagram showing coupling connection formed between the rod of external accessory and a hole of the second linkage member according to some embodiments.
FIG. 38 is a schematic diagram showing a first linkage member pushing a second linkage member to trigger a passive-triggered external accessory according to some embodiments.
FIG. 39 is a schematic diagram showing an active-driven external accessory pushing the second linkage member to further push a third linkage member for trip activation according to some embodiments.
FIG. 40 is a schematic diagram of the external accessory linkage mechanism assembled on the circuit breaker (opening state) according to some embodiments.

DETAILED DESCRIPTION

To further illustrate the embodiments, the present disclosure provides accompanying drawings. These drawings form part of the disclosed content, primarily serving to explain the embodiments and interpret operational principles of the embodiments in conjunction with relevant descriptions in the specification. With reference to these contents, those skilled in the art should understand other possible implementations and advantages of the present disclosure. Components in the drawings are not drawn to scale, and similar component symbols are generally used to indicate similar components.
The present disclosure will now be further explained in conjunction with the accompanying drawings and specific implementations.
As shown in FIGS. 1-4, embodiments of the present disclosure provide a circuit breaker, more specifically a residual current-operated circuit breaker, comprising a housing 100 and a conductive system 3. The housing 100 is formed by fixedly assembling an upper cover 1001 and a base 1002. The conductive system 3 is disposed inside the housing. Referring to FIG. 4, the conductive system 3 includes a contact assembly comprising a movable contact 301 and a stationary contact 302, as well as terminals 300 and conductive copper bar to form the current path when energized. The movable contact 301 has a movable stroke relative to the stationary contact 302 to achieve contact or separation, thereby realizing the opening and closing operations of the circuit breaker.
As shown in FIG. 2, the inner chamber of the housing 100 further contains a zero-sequence current transformer 1003 for residual current measurement, an arc chute plates 1004 for arc extinguishing, and an electromagnetic trip actuator 4 for trip opening. The housing 100 is also equipped with a test button 41 for leakage protection function verification. For convenience of description, the following directional definitions are established in this embodiment: the height direction of the circuit breaker, i.e., the Z1 and Z2 directions in FIG. 2, are defined as up and down directions respectively; the width direction, i.e., the X1 and X2 directions in FIG. 2, are defined as left and right directions respectively; and the length direction, i.e., the Y1 and Y2 directions in FIG. 2, are defined as front and rear directions respectively.
The circuit breaker further includes an operating linkage assembly 2. Referring to FIGS. 4 and 5, the operating linkage assembly 2 comprises a first side plate 22 and a second side plate 23 arranged opposite each other in the left-right direction. The first side plate 22 and second side plate 23 are assembled together to form the mounting base of the operating linkage assembly 2. The operating linkage assembly 2 further includes a handle 11, a first link 13, a second link 14, a third link 15, a trip latch 17, a reset lever 18, and a locking catch 20 disposed between the first side plate 22 and second side plate 23. The handle 11, first link 13, second link 14, and third link 15 constitute the operating mechanism of the circuit breaker, which controls the contact movement and separation movement of the movable contact 301 through manual operation of the handle 11. The trip latch 17, reset lever 18, and locking catch 20 constitute the trip mechanism of the circuit breaker, which cooperates with the electromagnetic trip actuator 4 to achieve trip opening of the circuit breaker.
Specifically, the handle 11 is rotatably connected to the first side plate 22. Referring to FIGS. 6 and 8, in this embodiment, the handle 11 is rotatably inserted into a first insertion hole 2201 on the first side plate 22 via its handle shaft 1101. One end of the first link 13 is hinged to the handle 11, while the other end of the first link 13 is hinged to both the second link 14 and third link 15 at the same pivot point. Specifically, referring to FIGS. 4, 5, and 8-10, the first link 13 in this embodiment is a U-shaped rod. The second link 14 has a second insertion hole 1401 at one end and a third insertion hole 1402 at the other end. The third link 15 has a fourth insertion hole 1501 at one end and a fifth insertion hole 1502 at the other end. The second insertion hole 1401 and fourth insertion hole 1501 are arranged to overlap. One end of the first link 13 is rotatably inserted into a sixth insertion hole 1103 on the handle 11, while the other end of the first link 13 is simultaneously rotatably inserted into both the second insertion hole 1401 and fourth insertion hole 1501.
A movable contact support 16 is hinged to the third link 15. Specifically, referring to FIGS. 4, 10, and 11, the third link 15 and the movable contact support 16 are hinged by pivot shaft inserted in the fifth insertion hole 1502 of the third link 15 and a seventh insertion hole 1601 on the movable contact support 16. As shown in FIG. 11, the movable contact support 16 is also hinged to the housing 100 via a protruding column 1602 disposed on the movable contact support 16. The movable contact 301 is mounted on the movable contact support 16 and moves with it. For example, the movable contact 301 may be fixed or hinged to the movable contact support 16. In this embodiment, the movable contact 301 is hinged to the movable contact support 16. One end of the movable contact 301 is limited in position on the movable contact shaft 16 by an elastic member. During overtravel movement of the movable contact 301, when the other end is restricted by the stationary contact 302, the one end of the movable contact 301 moves away from the limiting position on the movable contact shaft 16 under the action of the elastic member.
The trip latch 17 and locking catch 20 are rotatably connected to the first side plate 22, while the reset lever 18 is rotatably connected to the second side plate 23. Specifically, referring to FIGS. 6-7 and 12-15, the trip latch 17 is hinged to the first side plate 22 via an eighth insertion hole 1702 and a ninth insertion hole 2203 via a pivot shaft; the reset lever 18 is rotatably inserted into a tenth insertion hole 1802 and a reset lever shaft 2301 on the second side plate 23; the locking catch 20 is rotatably inserted into an eleventh insertion hole 2204 on the first side plate 22 via its locking catch shaft 2002.
As shown in FIG. 12, the trip latch 17 also has a twelfth insertion hole 1701 in the middle section along the length of the trip latch17. As shown in FIG. 9, a pivot shaft is inserted in the third insertion hole 1402 of the second link 14 and the twelfth insertion hole 1701.
The above description enumerates various hinging methods. These hinging approaches may be interchangeable in other embodiments, as long as the hinging function is achieved.
In this embodiment, some components in the operating linkage assembly 2 are rotatably connected to the first side plate 22 (e.g., the trip latch 17), while others are connected to the second side plate 23 (e.g., the reset lever 18). However, it is obvious that in other embodiments these components may be arbitrarily changed to be rotatably connected to the first side plate 22 and/or second side plate 23. The first side plate 22 and second side plate 23 represent just one specific embodiment. In other embodiments, any mounting base that allows these components (e.g., the trip latch 17 and reset lever 18) to be rotatably mounted would suffice. This mounting base does not necessarily to be the specific structure of the first side plate 22 and second side plate 23 in this embodiment. This mounting base could alternatively be a fixed mounting plate inside the housing 100, or even the inner wall of the housing 100 itself.
In summary, in the operating linkage assembly 2, the handle 11 and the trip mechanism components (namely the trip latch 17, reset lever 18, and locking catch 20) are all rotatably mounted. One end of the first link 13 is hinged to the handle 11, while the other end is hinged to both the second link 14 and third link 15 at the same pivot point. The second link 14 is additionally hinged to the trip latch 17, and the third link 15 is additionally hinged to the movable contact support 16. The movable contact 301 is mounted on the movable contact support 16 and moves with the movable contact support 16.
The locking and tripping principles of the trip mechanism will now be explained. Referring to FIGS. 4 and 12-18, the trip latch 17 is provided with a first engagement portion 1703, correspondingly, the reset lever 18 is provided with a first pressing portion 1801. The reset lever 18 is further provided with a second engagement portion 1803, correspondingly, the locking catch 20 is provided with a second pressing portion 2001. The relative positions of the trip latch 17, reset lever 18, and locking catch 20 are configured such that through their relative rotation, the second pressing portion 2001 can engage with the second engagement portion 1803 while simultaneously the first pressing portion 1801 engages with the first engagement portion 1703, thereby restricting rotation of the trip latch 17. As shown in FIG. 4, when the circuit breaker is in the closed state, the locking catch 20 presses downward on the second engagement portion 1803 of the reset lever 18 with its second pressing portion 2001, while simultaneously the reset lever 18 presses downward on the first engagement portion 1703 of the trip latch 17 with its first pressing portion 1801, meaning the trip latch 17 is now limited and locked and prevented from swinging upward.
As shown in FIG. 5, the handle 11 is equipped with a first elastic member 1006 (handle spring). It should be understood that when the locking catch 20 is engaged and the circuit breaker switches from manual open state (FIG. 17) to manual closed state (FIG. 4) through operation of the handle 11, the handle spring stores energy, and the handle 11 transmits an upward swinging force (pulling force) to the trip latch 17 through the first link 13 and second link 14. However, due to the locking by the reset lever 18 and locking catch 20, the trip latch 17 cannot swing upward, meaning that in the closed state, the trip latch 17 is in a locked state in which the force is balanced with that of the reset lever 18 and locking catch 20. Since the trip latch 17 is locked (the trip latch 17 will not rotate), when the trip latch 17 is manual opening and closing, the second link 14 will rotate around its pivot point A with the trip latch 17, thus driving the third link 15, the movable contact support 16 and movable contact 301 to move. When the locking catch 20 is released, this force balance is disrupted, causing trip opening. Referring to FIG. 4, when the locking catch 20 is actuated by the electromagnetic trip actuator 4 and the second pressing portion 2001 separates from the second engagement portion 1803 of the reset lever 18 (in the view shown in FIG. 4, the second pressing portion 2001 rotates clockwise), the trip latch 17 will push the reset lever 18 swing upward until the first pressing portion 1801 can no longer restrain the first engagement portion 1703, then the trip latch 17 is released (tripped) and swings rapidly clockwise (in the specific view state of FIG. 4,the trip latch 17 rotates about pivot point B with the mounting base), which drives the second link 14 to rotate about pivot point B of the trip latch 17 and the mounting base, so as to quickly realize the circuit interruption. FIG. 18 shows the approximate state of the trip mechanism during the instant of tripping (the final state is also affected by the reset spring, which will be explained below).
The key difference between the trip mechanism of this embodiment and conventional designs is the addition of the reset lever 18. In other embodiments, the locking catches 20 could act directly on the trip latch 17, meaning the locking catch 20 alone could complete the locking of the trip latch 17. For example, the locking catch 20 could be hinged at the rear side of the trip latch 17 (approximately at the hinged position of the reset lever 18 in this embodiment). Due to space constraints inside the circuit breaker, the trip latch 17 is typically small (short), resulting in a short force arm. With constant torque on the trip latch 17, a shorter force arm means greater force exerted by the trip latch 17 on the locking catch 20. Correspondingly, the locking force required by the locking catch 20 would also be greater, leading to higher unlocking force requirements. However, the push force and push distance of the push rod of the conventional electromagnetic trip actuators are both small, so the tripping force required by the locking catch 20 is too large, and the push force of the electromagnetic trip actuator 4 might not be able to trip the mechanism. When the residual current appears in the circuit and reaches the rated value (leakage) of the circuit breaker, it is impossible to guarantee that the contact will be disconnected in the case of leakage fault.
In this embodiment, the reset lever 18 is added, the locking catch 20 first locks the reset lever 18, and then the reset lever 18 locks the trip latch 17. In other words, the trip latch 17 first applies force to the reset lever 18, then the reset lever 18applies force to the locking catch 20. Moreover, in this embodiment, the reset lever 18 is a force-reducing lever structure. As shown in FIG. 15, the reset lever 18 includes a first lever arm 181 and a second lever arm 182, wherein the first pressing portion 1801 is disposed on the first lever arm 181 and the second engagement portion 1803 is disposed on the second lever arm 182. The first torque arm L1 of the first pressing portion 1801 is smaller than the second torque arm L2 of the second engagement portion 1803, as shown in FIG. 4. the first torque arm L1 is the distance between the force application point where the first engagement portion 1703 of the trip latch 17 acts on the first pressing portion 1801 of the first lever arm 181 of the reset lever 18 and the center point of the reset lever shaft 2301. The second torque arm L2 is the distance between the force application point where the second pressing portion 2001 of the locking catch 20 acts on the second engagement portion 1803 of the second lever arm 182 of the reset lever 18 and the center point of the reset lever shaft 2301. Through the action of the reset lever 18 with its force-reducing lever structure, while maintaining constant torque on the trip latch 17, the force exerted by the trip latch 17 on the locking catch 20 becomes smaller, and the tripping force required by the electromagnetic trip actuator 4 to unlock the locking catch 20 is also reduced, ensuring automatic contact separation during leakage faults.
The trip latch 17 is a swing arm structure. As shown in FIGS. 12 and 15, in this embodiment, the first engagement portion 1703 and second engagement portion 1803 are engagement surfaces (or could be engagement edges) disposed at the terminal ends of the trip latch 17 and second lever arm 182 respectively. This ensures that once the first engagement portion 1703 and second engagement portion 1803 are released, the trip latch 17 can quickly trip and jump up, improving tripping response speed. The first pressing portion 1801 and second pressing portion 2001 are corner structures formed by the intersection of two planes. Specifically, as shown in FIG. 15, the first pressing portion 1801 has two planes: a first plane 18011 and a second plane 18012. As shown in FIG. 13, the second pressing portion 2001 has two planes: a third plane 20011 and a fourth plane 20012. Therefore, when the locking catch 20 rotates by a certain angle, once the second engagement portion 1803 slides out of the corner-shaped second pressing portion 2001, it can quickly separate from the second pressing portion 2001. Similarly, when the reset lever 18 rotates by a certain angle, once the first engagement portion 1703 slides out of the corner-shaped first pressing portion 1801, it can quickly separate from the first pressing portion 1801. To facilitate resetting of the trip latch 17, as shown in FIGS. 4 and 15, the first plane 18011 of the first pressing portion 1801, which is relatively upper, has a greater slope, so that when the trip latch 17 resets after tripping, this more steeply sloped first plane 18011 can serve as a guide surface to reliably reset the trip latch 17. The same principle applies to the design of the two planes forming the second pressing portion 2001.
In this embodiment, as shown in FIG. 15, the first length d1 of the first lever arm 181 is smaller than the second length d2 of the second lever arm 182, and the second engagement portion 1803 is disposed at the terminal end of the second lever arm 182, ensuring that the first torque arm L1 of the first pressing portion 1801 is smaller than the second torque arm L2 of the second engagement portion 1803 (as shown in FIG. 4). Moreover, in this embodiment, the first lever arm 181 and second lever arm 182 rotate together about the rotation axis R1 of the reset lever 18, and the first lever arm 181 and second lever arm 182 protrude in the same direction (e.g., the direction indicated by the solid arrow in FIG. 15), with different protrusion heights. This arrangement minimizes the space occupied by the reset lever 18 and reduces its length, saving installation space while avoiding interference with other internal components of the circuit breaker. On the other hand, the trip latch 17 cooperating with the first pressing portion 1801 and the locking catch 20 cooperating with the second engagement portion 1803 are offset in the left-right direction (refer to FIG. 24, i.e., the X1 and X2 directions), thereby utilizing the lateral space of the circuit breaker to avoid interference between the movements of the trip latch 17 and locking catch 20, and enabling more compact and rational arrangement of the trip mechanism. In other embodiments, the first lever arm 181 and second lever arm 182 may form a small acute angle α, presenting a V-shaped as shown in FIG. 25. Although this can also effectively reduce the space occupied by the reset lever 18, it may potentially interfere with components below the reset lever 18 such as the contact assembly and arc chute plates. Of course, without considering space constraints, in other embodiments the first lever arm 181 and second lever arm 182 could alternatively be two collinear lever arms extending in opposite directions (i.e., the first lever arm 181 and second lever arm 182 are located at opposite sides of the rotation axis R1 and collinear), or form an obtuse angle.
In this embodiment, the operating mechanism and contact assembly are arranged roughly in up-down direction, while the trip mechanism is arranged roughly in front-rear direction, forming a cross-shaped layout that fully utilizes the length and height space of the circuit breaker. To maximize the length of the reset lever 18 within the limited internal space of the circuit breaker, in this embodiment the constrained end of the reset lever 18 is hinged to the second side plate 23 at the rear side of the trip latch 17, while the locking catch 20 is hinged to the first side plate 22 at the front side of the trip latch 17. As shown in FIG. 4, the reset lever 18 extends from its constrained end to its free end from rear to front, thereby maximizing utilization of the length space in the front-rear direction of the circuit breaker and increasing the second torque arm L2 of the second engagement portion 1803. Furthermore, in this embodiment, the constrained end of the reset lever 18 is hinged to the second side plate 23 directly behind the trip latch 17, while the locking catch 20 is hinged to the first side plate 22 obliquely above the front side of the trip latch 17, making the reset lever 18 extend diagonally. This arrangement further increases the second torque arm L2 of the second engagement portion 1803. On the other hand, hinging the locking catch 20 obliquely above the front side of the trip latch 17 to the first side plate 22 also prevents interference between the locking catch 20 and movable contact support 16 during operation. In this embodiment, the locking catch 20 and movable contact support 16 are arranged up-down arrangement, improving structural compactness.
In this embodiment, the handle 11 and reset lever 18 are rotatably mounted on the mounting base in an upper-lower configuration. The mounting base is provided with a disk-shaped connection seat 2309 for installing the handle 11, while the reset lever 18 is configured as a curved swing arm structure matching the contour of the disk-shaped connection seat 2309 to provide clearance, thereby enhancing the compactness of the internal structure of the circuit breaker.
As shown in FIGS. 13 and 16, a protrusion 2006 is fixed on the locking catch 20 to abut against the free end (i.e., the terminal end) of the reset lever 18, thereby controlling the overlapping amount between the second engagement portion 1803 and second pressing portion 2001. It should be understood that a larger overlapping amount requires a greater trip stroke for the locking catch 20 to disengage from the reset lever 18. Therefore, in this embodiment, the trip stroke of the locking catch 20 can be controlled by modifying the protrusion height of the protrusion 2006, facilitating calibration according to actual product specifications.
Referring to FIGS. 2 and 19-21, the unlocking drive of the electromagnetic trip actuator 4 on the locking catch 20 is implemented through a linkage member 24. Both the electromagnetic trip actuator 4 and linkage member 24 are disposed at the side of the second side plate 23 away from the trip mechanism. In this embodiment, the linkage member 24 is a seesaw structure, rotatably mounted on the shaft 2303 of the second side plate 23 via its thirteenth insertion hole 2401. The linkage member 24 is provided with a first actuating portion 2403 and second actuating portion 2402 radially extending outward, the first actuating portion 2403 is positioned near the push rod (not shown) of the electromagnetic trip actuator 4. As shown in FIG. 14, the locking catch 20 is provided with a protruding column 2005 that extends through the second side plate 23 to the vicinity of the second actuating portion 2402. When the push rod of
the electromagnetic trip actuator 4 acts, it pushes the first actuating portion 2403, causing the linkage member 24 to rotate, and subsequently the second actuating portion 2402 pushes the protruding column 2005 to unlock the locking catch 20.
The linkage member 24 is also equipped with a reset member to drive both the linkage member 24 and the push rod of the electromagnetic trip actuator 4 to reset after the circuit breaker trips. As shown in FIG. 19, the reset member in this embodiment is a torsion spring 25 installed on the linkage member 24. The first arm of the torsion spring 25 abuts against a first contact surface 2404 on the linkage member 24, while the second arm is positioned near the movable contact support 16 (specifically near a second contact surface 1603 on the movable contact support, as shown in FIG. 11). When the movable contact support 16 rotates to the open position, its second contact surface 1603 pushes the second arm of the torsion spring 25, causing the first arm of the torsion spring 25 to generate torsional elastic force that drives the linkage member 24 to rotate, thereby resetting the push rod of the electromagnetic trip actuator 4. The electromagnetic trip actuator 4 may alternatively be other types of trip actuators in other embodiments, such as thermal or under-voltage trip actuators.
As shown in FIG. 5, the handle 11, reset lever 18, and locking catch 20 are respectively equipped with a first elastic member 1006, second elastic member 1007, and third elastic member 1008. The first elastic member 1006 has one end acting on the mounting base (e.g., the first side plate 22 or second side plate 23 in this embodiment) and the other end acting on the handle 11, providing elastic force to rotate the handle 11 toward the open position. The second elastic member 1007 has one end acting on the mounting base and the other end acting on the reset lever 18, providing elastic force to rotate the reset lever 18 toward the locking position where it presses against the trip latch 17, thereby resetting the reset lever 18 after the trip mechanism is released and the press-lock between the reset lever 18 and trip latch 17 is disengaged. The third elastic member 1008 has one end acting on the mounting base and the other end acting on the locking catch 20, providing elastic force to rotate the locking catch 20 toward the locking position where it presses against the reset lever 18, thereby resetting the locking catch 20 after the trip mechanism is released and the press-fit between the locking catch 20 and reset lever 18 is disengaged. For clarity, simply put, in the specific view angle of FIG. 18 showing the approximate state during tripping, the first elastic member 1006 provides clockwise rotational force on the handle 11, the second elastic member 1007 provides clockwise rotational force on the reset lever 18, and the third elastic member 1008 provides counterclockwise rotational force on the locking catch 20 (the rotation directions are indicated by arrows in FIG. 18). When the circuit breaker trips, under the elastic force of the first elastic member 1006, the handle 11 rotates to the open position and drives the trip latch 17 to swing downward for reset through the force transmission of the first link 13 and second link 14. Subsequently, the reset lever 18 and locking catch 20 reset under the action of the second elastic member 1007 and third elastic member 1008, respectively. In this embodiment, to enhance the compactness of the trip mechanism structure, the free end of the reset lever 18 is positioned above the rotation axis (axis of the locking catch shaft 2002) of the locking catch 20. Since the locking catch 20 lies in the reset path of the reset lever 18, a clearance notch 2007 (as shown in FIG. 16) is provided below the second pressing portion 2001 of the locking catch 20 to allow downward reset stroke for the reset lever 18. As shown in FIG. 18, a first stopper 2306 is provided below the trip latch 17 and reset lever 18. When the trip latch 17 and reset lever 18 swing downward to reset, they abut against the first stopper 2306, which limits them to an appropriate lowest extreme position, preventing excessive downward swing that would hinder their return to the press-fit state. In this embodiment, the first stopper 2306 is the bottom wall of the second side plate 23, while in other embodiments it could be an additional stopper component, such as an independently installed baffle. At this point, if the circuit breaker in the tripped state is manually switched back to the closed position, the trip latch 17 will again be lifted by the transmission of the handle 11 to press against the reset lever 18, forming a press-fit, and push the reset lever 18 upward to press against the locking catch 20, forming another press-fit, thereby completing a full reset of the trip mechanism.
Additionally, a second stopper 2307 is provided above the reset lever 18 (in this embodiment, the second stopper 2307 is the top wall of the second side plate 23, while in other embodiments it could be another stopper component) to control the highest extreme position of upward swing of the reset lever 18, ensuring reliable reset.
In this embodiment, the first elastic member 1006, second elastic member 1007, and third elastic member 1008 are all torsion springs. In other embodiments, they could be tension springs, compression springs, or other elastic members, with adaptive changes to their installation and connection positions to provide equivalent motion potential energy.
Clearly, the reset of the trip latch 17, reset lever 18, and locking catch 20 must follow a specific sequence. It should be understood that if the locking catch 20 resets before the reset lever 18, it would block the reset of the reset lever 18; if the reset lever 18 resets before the trip latch 17, it would block the reset of the trip latch 17. Therefore, the three must reset sequentially in the order of trip latch 17, reset lever 18, locking catch 20. To ensure reliable sequential reset, as shown in FIGS. 22 and 23, in this embodiment, one end of the reset lever 18 in its reset movement direction (the lower end in this embodiment) is provided with a first limit surface 1806, and the trip latch 17 is provided with a first stopping portion 1705 that can abut against the first limit surface 1806 to prevent the reset lever 18 from resetting. In this embodiment, the first stopping portion 1705 is a protruding shaft extending from the trip latch 17, and the first limit surface 1806 is a curved surface matching the motion trajectory of the first stopping portion 1705. Along the reset direction of the trip latch 17, a first termination end 18061 is provided on the first limit surface 1806. After the first stopping portion 1705 passes the first termination end 18061, it disengages from the first limit surface 1806, allowing the reset lever 18 to further reset. Similarly, one end of the locking catch 20 in its reset movement direction is provided with a second limit surface 2008, and the free end of the reset lever 18 serves as a second stopping portion that abuts against the second limit surface 2008 to prevent the locking catch 20 from resetting. The second limit surface 2008 is a curved surface matching the motion trajectory of the second stopping portion, and along the reset direction of the reset lever 18, a second termination end 20081 is provided on the second limit surface 2008. After the second stopping portion passes the second termination end 20081, it disengages from the second limit surface 2008, allowing the locking catch 20 to further reset.
The circuit breaker also includes a test mechanism. As shown in FIG. 19, the test mechanism comprises a test button 41, a first test spring 42, a second test spring 43, a movable contact spring 44, a shield cover 45 (a charged body), a connection spring 46, and a resistor 47. The test button 41 is mounted on the housing 100 and can only move vertically within a certain range. The first test spring 42 is a torsion spring installed on the second side plate 23, with one torsion arm resting on the test button 41 and the other on the shield cover 45. The second test spring 43 is also a torsion spring installed on the second side plate 23, with its two torsion arms resting at different positions on the second side plate 23. The movable contact spring 44 is a torsion spring installed on the movable contact support 16, with one torsion arm resting on the movable contact 301 and the other on the movable contact support 16, positioned near one torsion arm of the second test spring 43. The movable contact spring 44 moves with the movable contact support 16. The shield cover 45 covers the electromagnetic trip actuator 4 and is mounted on the second side plate 23. The connection spring 46 is installed on the second side plate 23, with one torsion arm resting on the shield cover 45 and the other pressing the pin of the resistor 47 against the shield cover 45. The resistor 47 is installed between the first side plate 22 and second side plate 23, with its other pin fixed to the incoming terminal block. When the circuit breaker is in the closed position, the movable contact spring 44 contacts the second test spring 43, allowing the test circuit to conduct when the test button 41 is pressed, thereby tripping the circuit breaker. When the circuit breaker is in the open position, the movable contact spring 44 and second test spring 43 are not electrically connected, and pressing the test button 41 cannot conduct the test circuit, protecting the circuit from damage. In this embodiment, the test circuit exclusively uses spring connections without soldered signal wires, reducing risks of wire breakage or cold joints. The components in the test circuit are functionally integrated: the shield cover 45 not only shields the electromagnetic trip actuator 4 from external magnetic fields but also serves as a conductor in the test circuit; the movable contact spring 44 not only generates contact pressure but also acts as a conductor in the test circuit, and the number of parts is saved.
Currently, for circuit breakers with trip opening functionality, a single trip opening function is increasingly unable to meet current needs. For example, if a circuit breaker needs to generate an alarm function when it trips and opens, an alarm device must usually be added to the circuit breaker; if the circuit breaker needs to have multiple trip methods simultaneously, other types of trip units must be configured in addition to the trip unit built into the circuit breaker. In other words, in addition to the functions inherent to the circuit breaker itself, there is an increasingly urgent need for modular improvement capabilities. However, the internal installation space of the circuit breaker body is limited, and the miniaturization design concept typically does not reserve installation space for additional modules. Therefore, circuit breakers that can flexibly connect to external accessories have become a focus of current circuit breaker structure research. However, circuit breakers on the market that can connect to external accessories often suffer from complex structures, low flexibility, and poor universality.
Based on this, referring to FIGS. 26-29, some embodiments of the present disclosure provide a circuit breaker, more specifically, a residual current-operated circuit breaker, including a housing 100a and a conductive system 3a. The housing 100a is formed by fixedly assembling and connecting an upper cover 1001a and a base 1002a. The conductive system 3a is arranged inside the housing 100a. Referring to FIG. 29, the conductive system 3a includes a terminal 300a, a movable contact 301a, a stationary contact 302a, and a conductive copper bar, forming a conductive circuit of the circuit breaker when energized. The movable contact 301a has a movable stroke relative to the stationary contact 302a to achieve contact or separation between the movable contact 301a and the stationary contact 302a, thereby realizing the opening and closing of the circuit breaker.
As shown in FIG. 27, the inner chamber of the housing 100a is also equipped with a zero-sequence current transformer 1003a for residual current measurement, an arc chute 1004a for arc extinguishing, and an electromagnetic trip unit 4a for achieving trip opening. The housing 100a is also fitted with a test button 1005a for leakage detection.
The circuit breaker also includes an operating linkage assembly 2a. Referring to FIGS. 29-30, the operating linkage assembly 2a includes a first side plate 22a and a second side plate 23a arranged opposite each other in the left-right direction. The first side plate 22a and second side plate 23a are assembled to form the mounting base of the operating linkage assembly 2a. The operating linkage assembly 2a also includes an operation mechanism, a trip mechanism, and an external accessory linkage mechanism mounted on the mounting base.
The operation mechanism includes a handle 11a, a first link 13a, a second link 14a, and a third link 15a; the trip mechanism includes a trip latch 17a, a reset lever 18a, and a locking catch 20a; the external accessory linkage mechanism includes a first linkage member 26a, a second linkage member 27a, and a third linkage member 29a. The operation mechanism controls the opening and closing movement of the movable contact 301a; the trip mechanism is connected to the operation mechanism and can interact with it to cooperate with the electromagnetic trip unit 4a to achieve trip opening of the circuit breaker. The external accessory linkage mechanism is used for linkage between the circuit breaker and external accessories (including active-driven accessories and passive-triggered external accessories).
Specifically, the handle 11a, trip latch 17a, reset lever 18a, and locking catch 20a are all rotatably mounted on the mounting base; one end of the first link 13a is hinged to the handle 11a, and the other end is hinged to the second link 14a and third link 15a at the same pivot point; the second link 14a is also hinged to the trip latch 17a; the third link 15a is also hinged to a movable contact support 16a, which is itself hinged to the housing 100a; the movable contact 301a is mounted on the movable contact support 16a and moves with it, for example, the movable contact 301a may be fixed or hinged to the movable contact support 16a. In this embodiment, the movable contact 301a is hinged to the movable contact support 16a, with one end of the movable contact 301a limited by an elastic member to a limit position on the movable contact shaft 16. During over-travel movement of the movable contact 301a, when the other end of the movable contact 301a is restricted by the stationary contact 302a, the one end of the movable contact 301a moves away from the limit position on the movable contact shaft 16 under the action of the elastic member.
In the trip mechanism, the locking catch 20a engages with the reset lever 18a, the reset lever 18a engages with the trip latch 17a, restricting rotation of the trip latch 17a. During manual opening and closing, the trip latch 17a is in a locked state in which the force is balanced with that of the reset lever 18a and locking catch 20a. Since the trip latch 17a is locked, during manual opening and closing, the second link 14a rotates about the pivot point A where it is hinged to the trip latch 17a, thereby driving the third link 15a, movable contact support 16a, and movable contact 301a to move, while the trip latch 17a does not rotate. When the locking catch 20a releases, this force balance is disrupted, causing trip opening. The trip latch 17a unlocks (releases), quickly driving the second link 14a to rotate about pivot point B where the trip latch 17a is hinged to the mounting base, thereby driving the movable contact 301a to trip opening and quickly achieve circuit interruption. The trip mechanism in this embodiment, in addition to the trip latch and locking catch, the reset lever 18a is added, causing the locking catch 20a to first lock the reset lever 18a, the reset lever 18a then locks the trip latch 17a. In other words, the trip latch 17a first applies force to the reset lever 18a; the reset lever 18a then applies force to the locking catch 20a. Thus, through the reset lever 18a, the force arm through which the trip latch 17a acts on the locking catch 20a is indirectly lengthened. With the torque of the trip latch 17a unchanged, the force the trip latch 17a applies to the locking catch 20a is smaller, and the release force required from the electromagnetic trip unit 4a to unlock the locking catch 20a is also reduced, ensuring automatic contact separation during leakage faults.
The operation mechanism and trip mechanism are both arranged between the first side plate 22a and second side plate 23a, while the external accessory linkage mechanism is mounted on the outer side of the first side plate 22a, placing the external accessory linkage mechanism and the operation mechanism/trip mechanism at different installation layer, improving space utilization and structural compactness within the circuit breaker. Moreover, the first side plate 22a separates the external accessory linkage mechanism, so that the external accessory linkage mechanism with more independent functions can interfere with the operation mechanism and trip mechanism less.
Referring to FIGS. 30-36, the first linkage member 26a is rotatably mounted on the mounting base and is coaxially linked with the trip latch 17a. In this embodiment, the first linkage member 26a is a semi-circular plate member, with its central hole 2601a hinged on shaft 2206a of the first side plate 22a, this shaft 2206a is coaxial with pivot point B of the trip latch 17a;
the first linkage member 26a also has a connection hole 2602a through which an interlock shaft engages with the trip latch 17a, achieving synchronous movement between the trip latch 17a and first linkage member 26a. In other embodiments, different connection methods may be used to connect the trip latch 17a with first linkage member 26a, such as fixing both to the same rotating shaft. The first linkage member 26a is used to drive the second linkage member 27a during the release movement of the trip latch 17a, so in other embodiments, the first linkage member 26a may alternatively be configured as a swing arm.
The second linkage member 27a is a swing arm rotatably connected to the mounting base, with its rotation center at point C. Specifically, the second linkage member 27a is hinged via its shaft 2701a to hole 2207a of the first side plate 22a, with its free end positioned near the first linkage member 26a to be driven by it. A first elastic member 28a (in this embodiment, a torsion spring) acts at one end on the mounting base and at the other end on the second linkage member 27a, providing reset force to swing the second linkage member 27a toward the first linkage member 26a. A limit post 33a is fixed at the side of the second linkage member 27a facing the first linkage member 26a, limiting its swing range. In other embodiments, the second linkage member 27a may alternatively be configured as an up-and-down linear-motion structure.
The indicator member 31a is a lever structure, a shaft 3101a rotatably connected in the hole 2209a of the first side plate 22a is provided at its mid-length portion. One end of the indicator member 31a is hinged to the movable contact support 16a via a U-shaped slot 3102a, when the movable contact support 16a rotates; the other end of the indicator member 31a is driven to deflect to different positions, indicating the status of the circuit breaker.
The third linkage member 29a is also a swing arm structure; the first end of the third linkage member 29a is hinged to the movable contact support 16a. Specifically, a hole 2901a is provided at one end of the third linkage member 29a, engaging with a protrusion (not shown) on the movable contact support 16a is rotatably connected in the hole 2901a. The third linkage member 29a is positioned beside the second linkage member 27a and can be driven by the second linkage member 27a. The locking catch 20a has a drive portion 201a that extends through the second side plate 22a to the side of the third linkage member 29a opposite the second linkage member 27a.
The second linkage member 27a has a coupling connection portion for connecting to external accessories. These external accessories refer to components outside the circuit breaker body that can interact with the circuit breaker, primarily falling into two categories in this embodiment: passive-triggered external accessories (such as auxiliary contact devices, alarm contact devices) and active-driven accessories (such as under-voltage releases, overvoltage releases, and shunt trips). The external accessory has a coupling mating portion that engages with the coupling connection portion of the second linkage member 27a, enabling mutual driving between them. As shown in FIG. 37, illustrating the connection between an external accessory 500a and the second linkage member 27a, in this embodiment, the coupling connection portion is a hole 2705a on the second linkage member 27a, while the coupling mating portion is a rod 600a inserted into the hole. Other embodiments may reverse this arrangement, the coupling mating portion is a hole and the coupling connection portion is a rod. The diameter of the hole 2705a is larger than rod 600a in this embodiment, so that the hole 2705a can adapt to the rods with more sizes and specifications, and the applicability is improved.
The working principle of the external accessory linkage mechanism is described as follows. Referring to FIGS. 31 and 38, if the external accessory 500a is a passive-triggered accessory such as an alarm contact device, when the trip latch 17a of the circuit breaker releases, the first linkage member 26a moves following the movement of the trip latch 17a and further pushes the second linkage member 27a to swing. The second linkage member 27a then pushes the pin 600a through the engagement between the hole 2705a and the rod 600a, thereby triggering the contact closure of the alarm contact device to generate an alarm signal.
Referring to FIGS. 31 and 39, if the external accessory 500a is an active-driven accessory such as an under-voltage release, when the under-voltage release detects an under-voltage condition, the rod 600a actively moves and pushes the second linkage member 27a through the engagement between the hole 2705a and the rod 600a. The second linkage member 27a further pushes the third linkage member 29a, the third linkage member 29a then actuates the drive portion 201a of the locking catch 20a, causing the circuit breaker body to perform a trip opening operation. By incorporating the external accessory linkage mechanism, this embodiment enables the circuit breaker to be modularly connected with external accessories. Moreover, a single set of external accessory linkage mechanism in this embodiment can be optionally configured with various different external accessories, significantly improving the flexibility of installing external accessories on the circuit breaker.
As shown in FIGS. 31, 34, and 35, the opposing sides of the second linkage member 27a and the third linkage member 29a are each provided with a first protrusion 2704a and a second protrusion 2904a that extend toward and approach each other. The mutual approach of the first protrusion 2704a and second protrusion 2904a enhances the response speed when the second linkage member 27a and third linkage member 29a push against each other for linkage.
In addition to the engagement between the hole and rod, other embodiments may employ different coupling connection structures for the coupling connection portion and coupling mating portion, such as magnetic connection, hinged connection, or detachable fixed connection.
Continuing to refer to FIGS. 31, 34, and 35, the second end 2902a of the third linkage member 29a is biased by the second elastic member 30a toward the shaft 3101a of the indicator member 31a in a direction away from the drive portion 201a, preventing the third linkage member 29a from accidentally triggering the locking catch 20a. In other embodiments,
the second end 2902a of the third linkage member 29a may not necessarily be biased against the shaft 3101a, as long as there is a stationary contact point for the second end 2902a to abut against. For example, the stationary contact point may be a protrusion extending from the second side plate 22a. Furthermore, in this embodiment, the first end of the third linkage member 29a is hinged to the movable contact support 16a. When the second end 2902a abuts against the stationary contact point, as shown in FIG. 40, the movable contact support 16a in this embodiment, when rotated to the open position, can drive the first end of the third linkage member 29a to pivot away from the second linkage member 27a, thereby moving out of the travel range of the second linkage member 27a. In this state, no matter how the second linkage member 27a moves, it cannot contact the third linkage member 29a, ensuring the circuit breaker can successfully close. (During the product closing process, if the rod 600a of the external accessory remains stationary, the second linkage member 27a stays stationary at the limit post 33a, while the third linkage member 29a moves with the movable contact support 16a to a position near the second linkage member 27a. When the external accessory activates, the rod 600a pushes the second linkage member 27a, which in turn pushes the third linkage member 29a, thereby triggering the locking catch to release and causing the product to trip open. If the rod 600a of the external accessory moves along with the accessory closing, the second linkage member 27a will follow the rod 600a to the position of the limit post 33a. During this process, the third linkage member 29a also moves with the movable contact support 16a, maintaining a certain gap with the second linkage member 27a at all times to ensure smooth closing of both the circuit breaker and the external accessory.)
In this embodiment, as shown in FIGS. 33 and 34, both the first protrusion 2704a and the second protrusion 2904a have a tapered shape with narrowing front ends. Consequently, when the third linkage member 29a pivots away from the second linkage member 27a, the angle change allows the first protrusion 2704a and second protrusion 2904a to quickly disengage, enabling the second protrusion 2904a to exit the travel range of the first protrusion 2704a more rapidly and ensuring they do not make contact again.
The first elastic member 28a and second elastic member 30a in this embodiment are torsion springs. However, in other embodiments, they may be tension springs, compression springs, or other types of elastic members, provided the installation method is adapted accordingly to ensure equivalent kinetic performance.
The disclosed embodiment also provides a combination switching device, which includes the circuit breaker described in the above embodiments and an external accessory coupled to the circuit breaker. Since this embodiment adopts the circuit breaker from the above embodiments, it achieves the same technical effects. The externally coupled accessories include, but are not limited to auxiliary contact devices, alarm contact devices, under-voltage releases, overvoltage releases, and shunt releases.
Although the present disclosure has been illustrated and described in conjunction with preferred embodiments, those skilled in the art should understand that various modifications in form and detail to the present disclosure, without departing from the spirit and scope defined by the appended claims, all fall within the protection scope of the present disclosure.

Claims

A trip mechanism for circuit breaker, comprising a rotatably mounted trip latch, a reset lever and a locking catch, wherein the reset lever is configured as a force-reducing lever structure comprising a first lever arm and a second lever arm, the trip latch is provided with a first engagement portion, the first lever arm is correspondingly provided with a first pressing portion, the second lever arm is provided with a second engagement portion, and the locking catch is correspondingly provided with a second pressing portion;
the relative positions of the trip latch, reset lever and locking catch are configured such that through their relative rotation, the second pressing portion engages with the second engagement portion while the first pressing portion simultaneously mates with the first engagement portion, so as to restrict rotation of the trip latch, wherein a first torque arm of the first pressing portion is shorter than a second torque arm of the second engagement portion.
The trip mechanism according to claim 1, wherein the first lever arm and second lever arm rotate together about a rotation axis of the reset lever, and the first lever arm and second lever arm protrude in a same direction with different heights, or the first lever arm and second lever arm form an acute angle and present a V-shape.
The trip mechanism according to claim 2, wherein rotation centers of the reset lever and locking catch are respectively positioned at two sides of a rotation center of the trip latch, such that the second lever arm extends from one side to another side of the rotation center of the trip latch.
The trip mechanism according to claim 1, wherein the trip latch is configured as a swing arm structure, the first engagement portion is disposed at a terminal end of the trip latch, and the second engagement portion is disposed at a terminal end of the second lever arm.
The trip mechanism according to claim 4, wherein the locking catch is provided with a protrusion abutting against the terminal end of the second lever arm, and an overlapping amount between the second engagement portion and second pressing portion is controlled by modifying a height of the protrusion.
A circuit breaker, comprising an operating mechanism, a contact assembly comprising a movable contact and a stationary contact, wherein the movable contact is mechanically linked to the operating mechanism and has a movable stroke relative to the stationary contact to realize the connection or disconnection of the circuit breaker, the circuit breaker further comprises a trip mechanism for circuit breaker tripping, and a trip actuator for triggering the trip mechanism, wherein the trip mechanism is according to any one of claims 1-5, the trip latch is mechanically linked to the operating mechanism, and the trip actuator is configured to drive the locking catch to move.
The circuit breaker according to claim 6, wherein taking length direction of the circuit breaker as front-rear direction and height direction as up-down direction, the operating mechanism and contact assembly are substantially arranged along the up-down direction, the trip mechanism is substantially arranged along the front-rear direction, thereby forming a cross-shaped layout.
The circuit breaker according to claim 7, wherein the reset lever is hinged at a rear side of the trip latch, the locking catch is hinged at a front side of the trip latch, such that the second lever arm extends from rear to front.
The circuit breaker according to claim 8, further comprising a movable contact support, wherein the movable contact is mounted on the movable contact support and moves along with the movable contact support, the reset lever is hinged at a direct rear side of the trip latch, the locking catch is arranged in an upper diagonal direction of a front side of the trip latch, such that the second lever arm extends obliquely upward, and the locking catch and movable contact support form an up-down arrangement.
The circuit breaker according to claim 7, wherein the operating mechanism comprises a handle rotatably mounted above the reset lever, and a disk-shaped connection base for mounting the handle, the reset lever is configured as a curved extension matching the contour of the connection base.
The circuit breaker according to claim 6, wherein taking a width direction of the circuit breaker as left-right direction, the first pressing portion and second engagement portion of the reset lever are offset in left-right direction, and the trip latch cooperating with the first pressing portion and the locking catch cooperating with the second engagement portion are also offset in left-right direction and not coplanar.
The circuit breaker according to claim 6, wherein the operating mechanism comprises a rotatable handle having two resting positions as open position and closed position, the handle is mechanically linked to both the trip latch and movable contact through a linkage mechanism, the linkage mechanism transmits force to the trip latch such that when the handle swings from the open position to the closed position, the handle pulls the first engagement portion of the trip latch against the first pressing portion, and indirectly pushes the second engagement portion against the second pressing portion, so as to lock the trip mechanism.
The circuit breaker according to claim 12, wherein the handle, the reset lever and the locking catch are respectively provided with a first elastic member providing elastic force to rotate the handle toward open position and indirectly reset the trip latch, a second elastic member providing reset force for the reset lever, and a third elastic member providing reset force for the locking catch.
The circuit breaker according to claim 13, wherein taking height direction of the circuit breaker as up-down direction, the second engagement portion is positioned above a rotation axis of the locking catch, a clearance notch is provided below the second pressing portion to allow a reset travel of the reset lever; and/or further comprising a first stopper fixed on a reset paths of the trip latch and reset lever to limit positions of the trip latch and reset lever.
The circuit breaker according to claim 13, wherein the trip latch can reset prior to the reset lever, and the reset lever can reset prior to the locking catch.
The circuit breaker according to claim 15, wherein one end of the reset lever in a reset movement direction is provided with a first limit surface, the trip latch has a first stopping portion that abuts the first limit surface to block the reset lever reset, a first termination end is provided on the first limit surface along a reset direction of the trip latch, such that after the first stopping portion passes the first termination end, the first stopping portion disengages from the first limit surface, allowing the trip latch to reset prior to the reset lever ; and/or one end of the locking catch in a reset movement direction is provided with a second limit surface, the reset lever has a second stopping portion that abuts the second limit surface to block locking catch reset, a second termination end is provided on the second limit surface along a reset direction of the reset lever, such that when the second stopping portion passes the second termination end, the second stopping portion disengages from the second limit surface, allowing the reset lever to reset prior to the locking catch.