Moving contact anti-falling structure
By designing a dynamic contact anti-fall structure in a plastic case circuit breaker, and using arc-shaped slide chutes and anti-fall components to improve the repulsive response speed and final pressure of the dynamic contacts, the problem of slow contact drop and response speed in the prior art is solved, and more efficient fault current breaking and smaller spring deformation is achieved.
Patent Information
- Application Number
- CN202421476513.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-26
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-06-26
AI Technical Summary
The current limit type contact structure in the existing plastic case circuit breaker has contact drop, resulting in the failure current not being effectively opened and cut, and the response speed is slow, the final pressure is small, and the movement stroke is small.
A dynamic contact anti-fall structure is designed, including a moving contact rotating seat, a moving contact, a curved chute, an anti-fall assembly, etc. Through the cooperation of the arc-shaped chute and an anti-fall assembly, the repulsive response speed and final pressure of the moving contact are improved.
The rapid repulsion of the moving contacts and a larger final pressure are achieved, ensuring effective breaking within a wider fault current range, reducing the deformation amplitude of the contact spring and reducing the risk of plastic deformation.
Smart Images
Figure CN222826340U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of circuit breakers and relates to a moving contact anti-drop structure. Background Art
[0002] As a branch-level distribution device of the power distribution system, the molded case circuit breaker requires higher and higher breaking capacity with the continuous increase of power grid capacity and the need for centralized power distribution. Therefore, the current-limiting contact structure has been widely used in molded case circuit breakers. However, the repulsion force of the contact of the current-limiting contact structure depends on the current passing through the contacts, that is, when the current value increases to a certain value, the moving and static contacts begin to repel under the simultaneous action of the circuit Ampere force and the Holm force between the moving and static contacts. After the arc is generated, the Holm force disappears. In addition, the periodic change of the AC current will cause the electric repulsion force to drop to less than the final pressure of the moving contact before the circuit breaker is disconnected. In addition, the moving contact may move to the highest position to produce a collision and be rebounded. The repelled moving contact will move from the repulsion position to the closed position, which causes the so-called contact drop phenomenon. The contact drop will cause the arc between the contacts to reignite and the fault current cannot be interrupted.
[0003] Chinese patent CN219575540U discloses a moving contact anti-drop structure of a molded case circuit breaker, which can effectively solve the contact drop phenomenon in the current limiting contact structure of the molded case circuit breaker, thereby avoiding the situation where the fault current cannot be interrupted. However, there are still one or more problems such as slow response speed, small final pressure, and small movement stroke. Utility Model Content
[0004] The purpose of the utility model is to provide a moving contact anti-drop structure which has a compact structure, miniaturization, faster repulsion response speed, large repulsion stroke and can provide greater final pressure.
[0005] The purpose of the utility model can be achieved through the following technical solutions:
[0006] A moving contact anti-drop structure, comprising:
[0007] A moving contact rotating seat is rotatably arranged in the circuit breaker;
[0008] The moving contact is rotatably arranged on the moving contact rotating seat, and the moving contact and the arc-shaped sliding groove are respectively arranged on the moving contact at two ends relative to the rotating center of the moving contact; the arc center of the arc-shaped sliding groove is eccentrically arranged relative to the rotating center of the moving contact, and the arc-shaped sliding groove has a proximal retaining wall close to the rotating center of the moving contact and a distal retaining wall far from the rotating center of the moving contact; the rotating center of the movable bracket is eccentrically arranged relative to the rotating center of the moving contact;
[0009] The anti-drop assembly comprises a movable bracket rotatably arranged on a movable contact rotating seat, a movable plate movably arranged on the movable bracket, a base abutted against the movable plate, a contact spring elastically abutted between the movable bracket and the base, and a sliding portion arranged on the movable plate; the elastic displacement direction of the movable plate points to the arc-shaped slide groove, and the sliding portion is slidably arranged in the arc-shaped slide groove;
[0010] During the rotation of the moving contact, the sliding part can move between two states: abutting against the distal retaining wall and abutting against the proximal retaining wall, and the straight line between the sliding part and the arc center of the arc-shaped slide groove sweeps across the rotation center of the movable bracket;
[0011] When the sliding part abuts against the distal baffle wall, the line connecting the rotation center of the movable bracket and the sliding part, and the line connecting the rotation center of the movable bracket and the sliding part when the sliding part abuts against the proximal baffle wall, are respectively located on both sides of the rotation center of the moving contact, so that under the elastic action of the contact spring, when the sliding part abuts against the distal baffle wall, the anti-drop assembly generates a positive torque on the moving contact to cause the moving contact to rotate toward the static contact; when the sliding part abuts against the proximal baffle wall, the anti-drop assembly generates a reverse torque on the moving contact to cause the moving contact to rotate away from the static contact.
[0012] Furthermore, the movable bracket and the movable plate are both U-shaped plate structures, and the openings are relatively staggered and buckled.
[0013] Furthermore, the movable plate includes a movable plate body, a limiting groove opened on the top of the movable plate body, and a sliding shaft slidably arranged in the limiting groove, and the sliding shaft is in sliding or rolling contact with the limiting groove and the arc-shaped sliding groove respectively.
[0014] Furthermore, through holes extending to the top are respectively opened on both sides of the movable plate, and bridge arms are formed between the through holes at the top;
[0015] The through hole is adapted to the proximal retaining wall or the distal retaining wall on the same side, so that during the rotation of the moving contact, the top of the proximal retaining wall or the distal retaining wall can pass through the corresponding through hole and abut against the bridge arm to push the movable plate to make the sliding part slide along the arc-shaped sliding groove.
[0016] Furthermore, the movable plate also includes a base disposed on the lower side of the top of the movable plate and adapted to the shape of the bridge arm and the through hole;
[0017] The two ends of the base are in contact with the inner wall of the movable plate;
[0018] The top end of the proximal retaining wall or the distal retaining wall can pass through the corresponding through hole and abut against the base to push the movable plate to make the sliding part slide along the arc-shaped sliding groove.
[0019] Furthermore, an upper positioning boss is provided at the lower side of the base, a lower positioning boss is provided at the bottom of the movable bracket, and two ends of the contact spring are sleeved between the upper positioning boss and the lower positioning boss.
[0020] Furthermore, two side walls of the movable bracket are provided with sliding slot holes, and the length direction of the sliding slot holes is consistent with the elastic expansion and contraction direction of the contact spring;
[0021] The two ends of the sliding shaft are slidably embedded in the sliding groove holes.
[0022] Furthermore, the edges of the two side walls of the movable plate are provided with limiting bosses, and the side walls of the movable bracket are limited between the limiting bosses of the two side walls of the movable plate.
[0023] Furthermore, the proximal retaining wall and the distal retaining wall are relatively inclined inwardly so that the sliding part can abut stably.
[0024] Furthermore, movable contact limiting protrusions are provided on the movable contact rotating seat and on both sides of the movable contact, so as to limit the rotation angle range of the movable contact.
[0025] Compared with the prior art, the utility model has the following beneficial effects:
[0026] (1) The utility model accelerates the speed of change of the force direction between the moving contact and the anti-drop assembly by designing an arc-shaped sliding groove of the moving contact. In addition, the motion transmission at multiple points between the moving contact and the anti-drop assembly accelerates the rotation response speed of the anti-drop assembly. The maximum resistance torque of the anti-drop assembly on the moving contact is effectively limited. Figure 4 After the position shown, the resistance amplitude and the resistance arm decrease rapidly, so the entire moving contact is repelled faster.
[0027] (1) After the moving contact is pushed open at a relatively small angle, the resistance from the anti-drop assembly is transformed into a gain force that helps the moving contact to be pushed open, which can trigger the anti-drop effect earlier. Therefore, this structure can push the moving contact open and lock it in the highest position within a wider fault current range.
[0028] (2) Each phase uses a group of contact springs to provide final pressure to the moving contact, which has higher space utilization, a wide variable range of spring parameters, and can provide a greater final pressure.
[0029] (3) Under this structure, the moving contact has a large opening angle, which can draw the arc longer during disconnection, thus facilitating arc extinguishing.
[0030] (4) The application of this anti-drop structure can reduce the deformation amplitude of the contact spring when the circuit breaker is disconnected compared to when it is closed, reduce the impact on the spring, effectively reduce the maximum deformation of the contact spring, and avoid the risk of plastic deformation. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 It is a structural schematic diagram of a moving contact anti-falling structure in the utility model;
[0032] Figure 2 for Figure 1 The middle AA section view is a schematic diagram of the internal structure of the moving contact anti-drop structure when the transmission mechanism is in a free state;
[0033] Figure 3 It is a schematic diagram of the internal structure of a moving contact anti-drop structure when the transmission mechanism is closed;
[0034] Figure 4 , Figure 5 , Figure 6 This is a schematic diagram of the moving contact opening process;
[0035] Figure 7 This is a schematic diagram of the final position of the moving contact after it is opened to prevent it from falling;
[0036] Figure 8 It is a schematic diagram of the movement process of a moving contact anti-drop structure after the transmission mechanism is tripped;
[0037] Fig. 9 It is a schematic diagram of the movement process of a moving contact anti-drop structure after the transmission mechanism is tripped;
[0038] Fig.10 This is a schematic diagram of the exploded view of the fall prevention component;
[0039] Fig.11 This is a schematic diagram of the structure of a moving contact of a moving contact anti-drop structure of the utility model;
[0040] Fig.12 This is a schematic diagram of the base structure of a moving contact anti-falling structure of the utility model;
[0041] Fig.13 This is a schematic diagram of the structure of a movable bracket of a moving contact anti-falling structure of the utility model;
[0042] Fig.14 The utility model is a schematic diagram of a movable plate structure of a moving contact anti-falling structure.
[0043] Description of the markings in the figure:
[0044] 1. Moving contact rotating seat; 11. Step surface; 2. Moving contact; 21. Arc-shaped slide groove; 22. Distal retaining wall; 23. Proximal retaining wall; 3. Shaft; 4. Anti-drop assembly; 41. Movable bracket; 411. Lower positioning boss; 412. Slide groove hole; 42. Movable plate; 421. Limiting groove; 422. Bridge arm; 423. Limiting boss; 43. Base; 431. Upper positioning boss; 432. Abutting boss; 44. Contact spring; 45. Sliding shaft; 5. Movable bracket rotating shaft; 6. Cover; 7. Static contact; 8. Limiting shaft. DETAILED DESCRIPTION
[0045] The following embodiments are implemented based on the above technical solution of the utility model, and provide detailed implementation methods and specific operation processes, but the protection scope of the utility model is not limited to the following embodiments.
[0046] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0047] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.
[0048] The transmission mechanism mentioned below refers to a mechanism in an existing circuit breaker that can drive the moving contact and the rotating seat of the moving contact to rotate through external force.
[0049] Embodiment 1:
[0050] like Figure 1 As shown, it is a moving contact anti-drop structure for the circuit breaker transmission mechanism. When breaking, the moving contact is acted upon by the electric repulsion force. After reaching a certain repulsion angle, the anti-drop structure starts to work and keeps the moving contact 2 at the highest position all the time, which is beneficial to arc breaking. After the mechanism is freely tripped, the moving contact 2 and the moving contact rotating seat 1 return to the normal state again, and the next reclosing cycle can be entered.
[0051] This embodiment is implemented in the following form: Figure 1 , Figure 2 , Fig.10As shown, the anti-drop assembly 4 is composed of a movable bracket 41, a movable plate 42, a base 43, a contact spring 44 and a sliding shaft 45. The movable bracket 41 is a U-shaped plate, the direction of the two side plates is recorded as the first direction, the direction perpendicular to the two side plates is recorded as the second direction, and the direction orthogonal to the first direction and the second direction is recorded as the third direction. The movable plate 42 is placed in the upper part of the movable bracket 41, and a base 43 is provided on the inner side of the movable plate 42. When in use, the movable plate 42 and the base 43 are located between the two side plates of the movable bracket 41. The wall surfaces on both sides of the movable bracket 41 can limit the movement of the movable plate 42 and the base 43 relative to the movable bracket 41 in the second direction. Along the second direction, the movable plate 42 is provided with a limiting boss 423 on both sides, and the limiting boss 423 extends to both sides of the movable bracket 41 in the third direction, so as to cooperate with the two sides of the movable bracket 41 to limit the movement of the movable plate 42 relative to the movable bracket 41 in the third direction. A contact spring 44 is provided between the base 43 and the movable bracket 41; one end of the contact spring 44 is sleeved on the upper positioning boss 431 on the base 43, and the other end is sleeved on the lower positioning boss 411 on the movable bracket 41, so as to ensure that the contact spring 44 does not fall off during movement. A limiting groove 421 is also provided on the other side of the movable plate 42, and the sliding shaft 45 is placed on the limiting groove 421. Both ends of the sliding shaft 45 are inserted into the slide slot hole 412 of the movable bracket 41. The sliding shaft 45, the movable plate 42 and the base 43 can slide relative to the movable bracket along the first direction where the slide slot hole 412 is located; the entire anti-drop assembly 4 is installed on the movable contact rotating seat 1 through the movable bracket rotating shaft 5, and can rotate flexibly around the movable bracket rotating shaft 5.
[0052] like Figure 1 , Figure 2 As shown, the moving contact 2 is mounted on the moving contact rotating seat 1 through the shaft 3 and can rotate around the shaft 3, and the arc-shaped slide groove 21 thereon contacts the sliding shaft 45; when the transmission mechanism is in a free tripping state, that is, when the embodiment is in a free tripping state, under the elastic force of the contact spring 44, the sliding shaft 45 presses against the arc-shaped slide groove 21 of the moving contact 2, providing a counterclockwise torque to the moving contact. In addition, the moving contact 2 contacts the step surface 11 on the moving contact rotating seat 1, and the telecentric retaining wall 22 on one side of the moving contact 2 also limits the position of the sliding shaft 45, so that the whole reaches a balanced state.
[0053] Working principle:
[0054] When the transmission mechanism is in a free tripping or re-tightening state, the relative position relationship of the anti-fall structure is as follows: Figure 2 As shown in the figure, the relative position relationship of the anti-drop structure after the transmission mechanism is closed is as follows Figure 3 As shown, at this time, the moving contact rotating seat 1 rotates to the lowest position, the moving contact 2 is in contact with the static contact 7 and is turned on, and the moving contact 2 is no longer in contact with the step surface 11 on the moving contact rotating seat 1.
[0055] When the current passing between the moving and static contacts is large, the electric repulsive force is greater than the final pressure provided by the contact spring 44, and the moving contact 2 begins to repel. Figure 4 Before the moving contact 2 is pushed to the position, the contact spring 44 is further compressed, but the force arm of the spring force that is finally transmitted to the moving contact is reduced, which slows down the increase speed of the resistance torque of the moving contact 2; when the moving contact 2 is pushed to Figure 4 When the moving contact 2 is in the positive position, the telecentric retaining wall 22 on the moving contact 2 begins to collide with the bridge arm 422 of the movable plate 42 and pushes the entire anti-drop assembly 4 to rotate counterclockwise, and the sliding shaft 45 is no longer in contact with the telecentric retaining wall 22; and at this time, the line connecting the axis line of the arc-shaped slide groove 21 and the axis line of the sliding shaft 45 just passes through the rotation center of the anti-drop assembly 4. Therefore, when the moving contact 2 passes this position, the reaction force of the arc-shaped slide groove 21 of the moving contact 2 on the anti-drop assembly 4 will generate a torque that causes the anti-drop assembly 4 to rotate counterclockwise. At the same time, the process of the sliding shaft 45 moving along the arc-shaped slide groove 21 after that is also a process of the contact spring 44 returning to its natural state. It can be concluded that the anti-drop assembly 4 will rotate counterclockwise rapidly, and the resistance amplitude and resistance arm of the anti-drop assembly 4 to the moving contact 2 will decrease rapidly, thereby making the moving contact 2 repelling speed very fast.
[0056] like Figure 5 As shown, during the rapid opening of the moving contact 2, the distal retaining wall 22 will separate from the bridge arm 422, and then contact the abutting boss 432 of the base 43, and continue to push the anti-drop assembly 4 to move for a certain distance before separating from it. Since the contact spring 44 is always in a compressed state, the sliding shaft 45 is always in contact with the arc-shaped slide groove 21 during the movement, and the sliding shaft 45 will slide to the other end of the arc-shaped slide groove 21 and contact the proximal retaining wall 23.
[0057] As the moving contact 2 is continuously pushed away, the line connecting the axis of the sliding shaft 45 and the axis of the movable support shaft 5 will pass through the rotation center of the moving contact 2. Figure 6 As shown, at this time, the direction of the torque of the anti-drop assembly 4 on the moving contact 2 is reversed, becoming a gain torque that promotes the repulsion of the moving contact 2. In addition, the inertial motion of the moving contact 2 itself under the action of the electric repulsive force causes the moving contact 2 to be quickly repelled to the highest position, such as Figure 7 As shown, at this time, the moving contact 2 is in contact with the cover 6 and is held in the highest position by the anti-drop assembly 4.
[0058] After the transmission mechanism of the circuit breaker triggers the trip, the moving contact rotating seat 1 starts to rotate clockwise under the drive of the transmission mechanism. Since the rotation center of the moving contact rotating seat 1 is not on the same straight line as the rotation center of the moving contact 2, the limit of the moving contact 2 by the cover 6 will gradually change to the limit of the moving contact 2 by the limit shaft 8. The limit shaft 8 is a component in the transmission mechanism. Figure 8When the movable plate bridge arm 422 is in the position shown, the other side of the movable plate bridge arm 422 touches the proximal retaining wall 23 of the moving contact. After the moving contact rotating seat 1 continues to rotate past this position, the anti-drop assembly 4 will start to rotate clockwise under the pressure of the proximal retaining wall 23. Fig. 9 As shown in FIG. 1 , when the near-center retaining wall 23 of the moving contact is separated from the bridge arm 422 of the movable plate, the connecting line between the axis line of the arc-shaped slide groove 21 and the axis line of the sliding shaft 45 has already crossed the axis line of the movable bracket rotating shaft 5. At this time, the anti-drop assembly will rotate clockwise under the torque provided by the reaction force of the moving contact on the anti-drop assembly until it returns to the Figure 2 The tripping status is shown.
[0059] Example 2
[0060] A moving contact anti-drop structure of a transmission mechanism, after the moving contact 2 is pushed away, the telecentric retaining wall 22 on the moving contact 2 first hits the bridge arm 422 of the movable plate 42, and pushes the entire anti-drop assembly 4 to rotate counterclockwise for a stroke, and then the axis line of the arc-shaped slide groove 21 and the axis line of the sliding shaft 45 cross the rotation center of the anti-drop assembly 4. At this time, the reaction force of the arc-shaped slide groove 21 of the moving contact 2 on the anti-drop assembly 4 generates a torque that makes the anti-drop assembly 4 rotate counterclockwise, which has a gain effect on the rotation of the anti-drop assembly. The rest is the same as in Example 1.
[0061] Example 3
[0062] A moving contact anti-drop structure of a transmission mechanism, after the moving contact 2 is repelled, the line connecting the axis line of the arc-shaped slide groove 21 and the axis line of the sliding shaft 45 first passes over the rotation center of the anti-drop assembly 4, and the reaction force of the arc-shaped slide groove 21 of the moving contact 2 on the anti-drop assembly 4 will generate a torque that causes the anti-drop assembly 4 to rotate counterclockwise, and prompt the anti-drop assembly to start rotating counterclockwise, and after a period of repelling stroke, the telecentric retaining wall 22 on the moving contact 2 hits the bridge arm 422 of the movable plate 42, and pushes the entire anti-drop assembly 4 to rotate counterclockwise. The rest is the same as the first embodiment.
[0063] Example 4
[0064] A moving contact anti-drop structure of a transmission mechanism, when the moving contact 2 is pushed to the highest position, it does not contact with the cover, but contacts with the limit shaft 8. The rest is the same as the first embodiment.
[0065] The above description of the embodiments is to facilitate the understanding and use of the utility model by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the utility model is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the utility model without departing from the scope of the utility model should be within the scope of protection of the utility model.
Claims
1. A moving contact anti-drop structure, characterized in that: include A moving contact rotating seat (1) is rotatably arranged in the circuit breaker; A moving contact (2) is rotatably disposed on a moving contact rotating seat (1), wherein a moving contact point and an arc-shaped sliding groove (21) are respectively disposed on the moving contact (2) at two ends relative to the moving contact's rotating center; the arc center of the arc-shaped sliding groove (21) is eccentrically disposed relative to the moving contact's rotating center, and the arc-shaped sliding groove (21) has a proximal retaining wall (23) close to the moving contact's rotating center and a distal retaining wall (22) far from the moving contact's rotating center; The anti-drop assembly (4) comprises a movable bracket (41) rotatably arranged on a movable contact rotating seat (1), a movable plate (42) movably arranged on the movable bracket (41), a base (43) abutting against the movable plate (42), a contact spring (44) elastically abutting between the movable bracket (41) and the base (43), and a sliding portion arranged on the movable plate (42); the elastic displacement direction of the movable plate (42) points to the arc-shaped slide groove (21), and the sliding portion is slidably arranged in the arc-shaped slide groove (21); the rotation center of the movable bracket (41) is eccentrically arranged relative to the rotation center of the movable contact; During the rotation of the moving contact (2), the sliding portion can move between two states: abutting against the distal retaining wall (22) and abutting against the proximal retaining wall (23), and a straight line between the sliding portion and the arc center of the arc-shaped sliding groove (21) sweeps across the rotation center of the movable bracket; The connecting line between the rotation center of the movable bracket and the sliding part is located on both sides of the rotation center of the moving contact when the sliding part abuts against the distal retaining wall (22) and when the sliding part abuts against the proximal retaining wall (23).
2. The moving contact anti-drop structure according to claim 1, characterized in that: The movable bracket (41) and the movable plate (42) are both U-shaped plate structures, and the openings are relatively staggered and buckled.
3. The moving contact anti-drop structure according to claim 2, characterized in that: The movable plate (42) comprises a movable plate body, a limiting groove (421) provided at the top of the movable plate body, and a sliding shaft (45) slidably arranged in the limiting groove (421), wherein the sliding shaft (45) is in sliding or rolling contact with the limiting groove and the arc-shaped sliding groove (21) respectively.
4. The moving contact anti-drop structure according to claim 3, characterized in that: Through holes extending to the top are respectively provided on both sides of the movable plate (42), and a bridge arm (422) is formed between the through holes at the top; The through hole is matched with a proximal retaining wall (23) or a distal retaining wall (22) located on the same side, so that during the rotation of the moving contact (2), the top end of the proximal retaining wall (23) or the distal retaining wall (22) can pass through the corresponding through hole and abut against the bridge arm (422) to push the movable plate (42) so that the sliding part slides along the arc-shaped sliding groove (21).
5. The moving contact anti-drop structure according to claim 4, characterized in that: The base (43) is arranged on the lower side of the top of the movable plate (42) and is adapted to the shape of the bridge arm (422) and the through hole; Two ends of the base (43) are in contact with the inner wall of the movable plate (42); The top end of the proximal retaining wall (23) or the distal retaining wall (22) can pass through the corresponding through hole and abut against the base (43) to push the movable plate (42) so that the sliding part slides along the arc-shaped sliding groove (21).
6. The moving contact anti-drop structure according to claim 5, characterized in that: An upper positioning boss (431) is provided on the lower side of the base (43), a lower positioning boss (411) is provided on the bottom of the movable bracket (41), and two ends of the contact spring (44) are sleeved between the upper positioning boss (431) and the lower positioning boss (411).
7. The moving contact anti-drop structure according to claim 4, characterized in that: Slide slot holes (412) are provided through the two side walls of the movable bracket (41), and the length direction of the slide slot holes (412) is consistent with the elastic expansion and contraction direction of the contact spring (44); Both ends of the sliding shaft (45) are slidably embedded in the sliding groove hole (412).
8. The moving contact anti-drop structure according to claim 5, characterized in that: Limiting bosses (423) are provided on the edges of the two side walls of the movable plate (42), and the side walls of the movable bracket (41) are limited between the limiting bosses (423) on the two side walls of the movable plate (42).
9. The moving contact anti-drop structure according to claim 5, characterized in that: The proximal retaining wall (23) and the distal retaining wall (22) are relatively inclined inwardly so that the sliding part can be in stable abutment.
10. The moving contact anti-drop structure according to claim 1, characterized in that: The movable contact rotating seat (1) is provided with movable contact limiting protrusions located on both sides of the movable contact (2), which are used to limit the rotation angle range of the movable contact (2).