Multi-axis layered linkage blade lever for miniature circuit breaker

Abstract

The utility model discloses a kind of multi-axis layered linkage blade lever for small circuit breaker, comprising: lever body, it is the special-shaped plate member of integrated molding;Main pivot hole, the lever body can rotate around the main pivot hole;First lateral transmission column, for cooperating with circuit breaker handle or superior linkage member;Second lateral transmission column, set in the middle pivot area;Third lateral transmission column;Wherein, the first lateral transmission column, the second lateral transmission column and the third lateral transmission column are layered arrangement along the lever body height direction, and form stepped overhanging structure in the lever body thickness direction, so that handle linkage member, blade driving member and spring energy storage member can be respectively located in different movement level.This multi-axis layered linkage blade lever for small circuit breaker integrates multiple components on a special-shaped plate lever body, with the characteristics of high part integration, good assembly precision and small movement interference.

Description

Technical Field

[0001] This utility model belongs to the field of low-voltage electrical technology, and in particular relates to a multi-axis layered linkage knife lever for a miniature circuit breaker. Background Technology

[0002] As a crucial protective component in low-voltage power distribution systems, miniature circuit breakers (MCBs) require their internal operating mechanisms to coordinate multiple functions—handle operation, contact actuation, tripping release, and spring energy storage—within an extremely limited housing space. The linkage lever within the operating mechanism is the core transmission component connecting the handle and the knife switch assembly; its structural design directly impacts the circuit breaker's operational reliability, assembly efficiency, and service life.

[0003] The linkage levers in the existing miniature circuit breaker operating mechanism generally have the following technical problems: In the traditional structure, the handle drive component, locking component, moving contact actuating component, spring hook component and limit component are often set as multiple independent parts. These parts need to be assembled with pins, riveting components or independent connecting components, resulting in a large number of parts, long assembly chain and large cumulative gap, which can easily cause problems such as unstable closing position, delayed tripping action or reduced opening synchronization.

[0004] While a single flat lever can achieve basic transmission functions, it is subjected to significant impact loads during the rapid disconnection of a circuit breaker. If multiple shaft holes, transmission columns, or mounting holes are simultaneously installed on the lever, stress concentration can easily occur at the edges of the holes, the base of the columns, and thin-walled corners, increasing the risk of fatigue fracture. Components inside the circuit breaker, such as the handle, latch, spring, and moving contact bracket, are typically located at different heights and thicknesses. If all transmission points of the lever are arranged on the same plane, motion interference with adjacent components is likely during lever swing. Adding shims, independent supports, or secondary linkages to avoid this interference would increase the thickness of the mechanism, hindering miniaturization design. Existing levers typically design the weight-reducing holes and mounting slots as isolated structures, without coordinating their design with the spring mounting direction, limiting path, and moving contact drive direction. This results in parts either having insufficient strength or excessive material and significant injection molding shrinkage deformation.

[0005] Therefore, there is an urgent need for a circuit breaker lever that can integrate multiple drive shafts, limit structures, and spring-loaded structures on a single lever body to solve problems such as the large number of parts, poor assembly accuracy, motion interference, and insufficient strength in existing technologies. Utility Model Content

[0006] The purpose of this invention is to provide a multi-axis layered linkage lever for miniature circuit breakers. This multi-axis layered linkage lever for miniature circuit breakers integrates multiple components on a single irregularly shaped plate-like lever body, featuring high component integration, good assembly precision, and minimal motion interference.

[0007] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0008] A multi-axis layered linkage lever for a miniature circuit breaker includes: a lever body, which is an integrally formed irregularly shaped plate-like component, divided along its height into an upper linkage zone, a middle pivot zone, and a lower drive arm zone; a main pivot hole, disposed in the middle pivot zone, for engaging with a fixed shaft within the circuit breaker housing, allowing the lever body to rotate around the main pivot hole; a first lateral transmission column, disposed in the upper linkage zone, extending to one side along the thickness direction of the lever body, for engaging with the circuit breaker handle or an upper-level linkage component; and a second lateral transmission column, disposed in the middle pivot zone, for engaging with the main pivot hole. The hole maintains a predetermined eccentric distance for engagement with the moving contact bracket or the knife block seat; the third lateral transmission column, located in the lower drive arm area, is positioned at a greater distance from the main pivot hole than the distance between the second lateral transmission column and the main pivot hole, and is used to engage with the knife block assembly or the spring mechanism; wherein the first lateral transmission column, the second lateral transmission column, and the third lateral transmission column are arranged in layers along the height direction of the lever body, and form a stepped outward structure in the thickness direction of the lever body, so that the handle linkage, the knife block drive, and the spring energy storage can be located at different motion levels respectively.

[0009] The present invention is further configured such that the first lateral transmission column, the main pivot hole and the second lateral transmission column are arranged in a non-collinear triangular arrangement on the lever body, so that the handle input force, pivot support force and gate driving force form a stable three-point force system.

[0010] The present invention is further configured such that: an annular bushing reinforcement is provided around the main pivot hole, and the annular bushing reinforcement protrudes relative to the surface of the lever body to increase the bearing area of ​​the shaft hole.

[0011] The present invention is further configured such that: the lever body is provided with an oblique hooking groove, the oblique hooking groove is inclined relative to the length direction of the lever body, and is used for hooking the end of the spring, so that the effective lever arm between the elastic element hooked in the oblique hooking groove and the main pivot hole changes with the lever angle.

[0012] The present invention is further configured such that: the second surface of the lever body is provided with a limiting hook groove, the limiting hook groove is located at the edge of the upper linkage area, and has a bent or hook-shaped guide contour. The opening direction of the limiting hook groove is adapted to the rotation direction of the lever body, and is used to guide the housing limiting post through the opening during assembly, and to form an anti-disengagement limiting through the hook contour during operation.

[0013] The present invention is further configured such that: the edge of the lever body is provided with a plurality of stepped clearance portions, the stepped clearance portions being matched with the outward extension height of the lateral transmission column in the thickness direction, for use in avoiding adjacent components inside the circuit breaker housing during lever rotation.

[0014] The present invention is further configured such that the lever body, the lateral transmission column, the annular bushing reinforcement, the oblique hook groove and the limiting hook groove are all integrally injection molded structures.

[0015] In summary, this utility model has the following beneficial effects:

[0016] 1. This utility model integrates multiple lateral transmission columns, main pivot holes, oblique hook slots, and limit hook slots onto a single lever body, enabling a single lever to simultaneously perform multiple functions such as handle input transmission, knife switch drive, tripping linkage, spring engagement, and motion limiting. Compared with traditional circuit breaker operating mechanisms, it reduces the use of independent parts such as handle linkages, knife switch forks, spring hooks, limit blocks, and spacer pads, reducing the number of parts by approximately 40% to 50%. This simplifies the assembly process, increases assembly efficiency by approximately 30%, and simultaneously lowers manufacturing and assembly costs.

[0017] 2. Traditional circuit breaker operating mechanisms are assembled from multiple parts via pins or riveted components. Each connection point has assembly gaps, and the accumulation of these gaps leads to a decrease in overall accuracy. This invention integrates multiple transmission points onto a single molded body. The relative positions of these transmission points are determined during injection molding, eliminating the cumulative errors caused by assembling multiple parts. The positional relationship between the main pivot hole and each transmission column is fixed in the mold, resulting in good batch consistency. The repeatability of the circuit breaker operating mechanism's operating position is improved by approximately 25%, and the stability of the closing position and the synchronization of the tripping action are significantly improved.

[0018] 3. The staggered arrangement of the three lateral drive columns in both the height and thickness directions allows the handle linkage, switch drive, and spring energy storage components to occupy different motion space levels. During lever swing, the adjacent mechanisms driven by each drive column move within their respective levels. This spatial isolation eliminates the risk of motion interference when multiple mechanisms operate simultaneously, improving the reliability of the circuit breaker operating mechanism during closing, opening, and tripping processes by approximately 35%.

[0019] 4. The irregular edge and stepped clearance allow the lever to adapt to the narrow space of the miniature circuit breaker housing while ensuring functional integrity. The clearance allows for partial relocation to adjacent mechanisms, creating a compact nesting between the lever and internal structures such as springs, contact frames, locking elements, and arc-extinguishing chambers. The height matching between the stepped clearance and the lateral transmission column in the thickness direction ensures that the multi-layer transmission function is achieved without increasing the housing thickness, which is beneficial for the miniaturization of circuit breaker products, reducing the overall thickness by approximately 15%. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an embodiment;

[0021] Figure 2 for Figure 1 A schematic diagram of the side view structure;

[0022] Figure 3 This is a schematic diagram of the rear view structure of an embodiment;

[0023] Figure 4 for Figure 3 A side view structural diagram.

[0024] In the figure: 1. First lateral transmission column; 111. Step reinforcement; 2. Second lateral transmission column; 3. Main pivot hole; 31. Annular bushing reinforcement; 4. Third lateral transmission column; 6. Angled hook groove; 7. Limiting hook groove; 8. Step clearance part; 9. Upper linkage area; 10. Middle pivot area; 11. Lower drive arm area. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings.

[0026] like Figure 1 , Figure 2 As shown, this embodiment provides a multi-axis layered linkage knife lever for miniature circuit breakers. The overall structure is an irregular plate-shaped integrated structure with a converging shape that is wider at the top and narrower at the bottom. It is used to install inside the miniature circuit breaker housing as the core linkage component of the operating mechanism.

[0027] The lever body is divided into three functional areas along its height: the upper linkage area 9, the middle pivot area 10, and the lower drive arm area 11. The upper linkage area 9 is located at the top of the lever body and has a relatively large width. The middle pivot area 10 is located in the middle of the lever body and is equipped with the main pivot hole 3 and the second lateral transmission column 2, serving as the fulcrum for the entire lever's movement. The lower drive arm area 11 extends away from the upper linkage area 9, gradually narrowing in width, and is equipped with the third lateral transmission column 4, forming a relatively long output arm.

[0028] The main pivot hole 3 is located at the center of the central pivot area 10. It is a circular through-hole structure used to mate with the fixed shaft inside the circuit breaker housing. A ring-shaped bushing reinforcement 31 is provided around the main pivot hole 3. The ring-shaped bushing reinforcement 31 protrudes relative to the lever body surface, forming a thickened bearing surface. The protrusion height of the ring-shaped bushing reinforcement 31 is determined according to the axial dimension of the fixed shaft and the axial movement requirements of the lever; the protrusion height is generally 0.5 to 1 times the wall thickness of the lever body. The ring-shaped bushing reinforcement 31 increases the cross-sectional thickness and axial bearing area at the main pivot hole 3, making the contact stress distribution between the lever and the fixed shaft of the housing more uniform. This helps reduce wear on the hole wall after long-term repeated operation and better restrains the axial movement of the lever.

[0029] The first lateral transmission column 1 is located in the upper linkage zone 9, extending to one side along the thickness direction of the lever body. The first lateral transmission column 1 is a cylindrical or elliptical cylindrical protrusion, used to cooperate with the circuit breaker handle or upper-level linkage component, receiving the closing and opening operating forces transmitted by the handle or upper-level linkage, serving as the force input end. The root of the first lateral transmission column 1 has a stepped reinforcement section 111, which creates a gradual transition connection between the first lateral transmission column 1 and the lever body, avoiding stress concentration at right-angle connections. The stepped reinforcement section 111 can be an annular stepped structure or a sloped transition structure, its function being to increase the cross-sectional dimensions of the root of the first lateral transmission column 1, reduce the stress gradient, and improve the bending resistance of the transmission column when subjected to the impact force of the handle. The outer end of the first lateral transmission column 1 is provided with a chamfer or rounded corner, facilitating assembly with adjacent linkage components and reducing edge wear during operation.

[0030] The second lateral transmission column 2 is located in the central pivot area 10 and extends to one side along the thickness direction of the lever body. The second lateral transmission column 2 maintains a predetermined eccentric distance from the main pivot hole 3, which is determined according to the stroke requirements of the gate assembly or the moving contact holder. When the lever rotates around the main pivot hole 3, the second lateral transmission column 2 moves along an arc trajectory centered on the main pivot hole 3, pushing or pulling the cooperating moving contact holder or gate seat to realize the opening and closing action of the contacts. The second lateral transmission column 2 is used to cooperate with the moving contact holder or gate seat as the force output end.

[0031] The third lateral drive column 4 is located in the lower drive arm area 11 and extends to one side along the thickness direction of the lever body. The distance between the third lateral drive column 4 and the main pivot hole 3 is greater than the distance between the second lateral drive column 2 and the main pivot hole 3, making the third lateral drive column 4 form a longer output lever arm. According to the lever principle, a longer lever arm can provide a larger output displacement. Therefore, the third lateral drive column 4 is used to cooperate with the knife switch assembly, return spring, quick-acting mechanism, or guide component in the housing to drive the knife switch to quickly separate during tripping, or to cooperate with the spring to complete energy storage and over-dead point action during closing.

[0032] The first lateral drive column 1, the second lateral drive column 2, and the third lateral drive column 4 are arranged in layers along the height of the lever body, located in the upper linkage zone 9, the middle pivot zone 10, and the lower drive arm zone 11, respectively. Simultaneously, the three lateral drive columns form a stepped outward extension structure along the thickness of the lever body, meaning each drive column extends from the side of the lever body at a different height. This layered arrangement and stepped outward extension structure allow the handle linkage, the knife switch drive, and the spring energy storage component to be located at different motion levels, avoiding mutual interference between multiple components within the miniature circuit breaker during operation.

[0033] The first lateral transmission column 1, the main pivot hole 3, and the second lateral transmission column 2 form a non-collinear triangular arrangement on the lever body. From a mechanical point of view, this triangular arrangement makes the handle input force, pivot support force, and gate drive reaction force form a stable three-point force system, avoiding the instability of force transmission that may be caused by collinear arrangement, and improving the stability of the lever when subjected to impact loads.

[0034] The lever body is provided with an oblique hook-in groove 6, which is inclined relative to the length direction of the lever body. The oblique hook-in groove 6 can be used for hooking the spring end, engaging the moving contact lever, assembling and positioning, or avoiding adjacent mechanisms. The inclination direction of the oblique hook-in groove 6 matches the swing trajectory of the lever around the main pivot hole 3, so that the effective lever arm between the elastic element hooked in the oblique hook-in groove 6 and the main pivot hole 3 changes with the lever rotation angle. In the initial stage of the closing process, the lever arm is small and the spring energy storage rate is low; as the lever rotates, the lever arm gradually increases and the spring energy storage accelerates; after passing the dead point, the spring releases energy, pushing the lever to quickly complete the remaining stroke, achieving a quick-acting disconnection effect.

[0035] like Figure 3 , Figure 4 As shown, the lever body is provided with a limiting hook groove 7, which is located at the edge of the upper linkage zone 9. The limiting hook groove 7 has a bent or hook-shaped guide profile, and is an irregularly shaped groove with a bent path and an opening structure. The opening direction of the limiting hook groove 7 is adapted to the rotation direction of the lever body, allowing it to be guided into the limiting post of the circuit breaker housing through the opening during assembly, while preventing the lever from disengaging from the limiting post during operation through the hook-shaped profile. When the lever rotates to the closing limit position or the opening limit position, the inner wall of the limiting hook groove 7 contacts the housing limiting post to form a stop, restricting the lever from continuing to rotate. The limiting hook groove 7 not only allows the lever to be guided in through the opening during assembly, but also prevents the lever from disengaging from the limiting post during operation through the hook-shaped profile, and can also limit the termination position after closing, opening, or tripping, reducing the use of additional limiting components.

[0036] The lever body has multiple stepped clearance sections 8 along its edge, which correspond to adjacent structures within the circuit breaker housing such as springs, contact frames, locking components, or arc-extinguishing chambers. These stepped clearance sections 8 create clearance space in non-load-bearing areas, allowing the lever to avoid interference with adjacent components during rotation. The stepped clearance sections 8 are coordinated with the outward extension height of the lateral transmission column in the thickness direction, enabling the lever body to achieve multi-point linkage without increasing the thickness of the circuit breaker housing. Compared to a standard rectangular lever, this irregular edge design ensures sufficient material is retained only along the load-bearing path, while creating clearance space in non-load-bearing areas, reducing both component volume and the risk of motion interference.

[0037] The lever body, all lateral transmission columns, annular bushing reinforcement 31, oblique hook groove 6, and limiting hook groove 7 are all integrally injection molded structures. Integral injection molding ensures the positional accuracy and connection strength between the various structures, eliminates accumulated assembly errors, and facilitates the design and manufacture of the injection mold. The lever body can be made of reinforced nylon, PBT, POM, or other wear-resistant, insulating engineering plastics suitable for low-voltage circuit breaker operating mechanisms.

[0038] In use, the lever of this utility model is installed inside the circuit breaker housing, and the main pivot hole 3 is fitted onto the fixed shaft of the housing, allowing the lever body to swing around the fixed shaft. The first lateral transmission column 1 cooperates with the handle or the upper linkage component, the second lateral transmission column 2 cooperates with the moving contact frame or the knife switch seat, the third lateral transmission column 4 cooperates with the spring mechanism or the knife switch assembly, the limiting hook groove 7 cooperates with the housing limiting column, and the oblique hanging groove 6 cooperates with the energy storage spring.

[0039] When closing the circuit breaker, the operating handle or the upper connecting rod pushes the first lateral transmission column 1, causing the lever body to rotate around the main pivot hole 3. During the lever rotation, the second lateral transmission column 2 drives the knife switch or moving contact assembly towards the stationary contact, while the third lateral transmission column 4, in conjunction with the spring, stores energy. Simultaneously, the oblique hook groove 6, in conjunction with the spring, gradually stores energy and passes the dead point, ultimately maintaining the knife switch or moving contact in a stable closed position. After the lever rotates to the closing limit position, the limit hook groove 7 contacts the housing limit post to form a stop, restricting further lever rotation.

[0040] When the circuit breaker is opened, the handle reverses its movement or the tripping mechanism releases the latch, the spring releases its stored energy, and the lever rotates rapidly in the opposite direction around the main pivot hole 3. The second lateral transmission column 2 and the third lateral transmission column 4 drive the knife switch or moving contact assembly to quickly disengage from the stationary contact. After the lever rotates to the opening limit position, the limit hook groove 7 contacts the housing limit post to form a stop, preventing the mechanism from overshooting.

[0041] During tripping, the internal thermomagnetic or electronic tripping mechanism of the circuit breaker releases the latch, and the lever can rotate rapidly under the action of the spring without relying on the handle and operating in complete reverse. Because multiple transmission columns are arranged in layers, the release of the tripping element, the action of the spring, and the disconnection of the switch can be completed simultaneously in different spatial levels, reducing action interference and improving the reliability of tripping and disconnection.

[0042] To verify the above technical solution, the present invention sets up the following experiment to verify the technical effect of the multi-axis layered linkage gate lever.

[0043] 1. The verification method adopted comparative testing, selecting 20 sets each of the lever sample of this utility model and the traditional split linkage mechanism (including independent parts such as handle linkage, gate fork, spring hook, and limit block) for parallel testing. The number of parts and assembly efficiency were evaluated by BOM list statistics and assembly time records; the assembly accuracy was detected by a coordinate measuring machine to check the position deviation of the transmission point; the reliability of the action was statistically analyzed by 10,000 closing and opening cycle tests to count the number of interference jams.

[0044] 2. Comparison of Technical Effects

[0045]

[0046] 3. Verification Conclusion

[0047] Test results show that the integrated design reduces the number of parts by approximately 45%, thereby improving assembly efficiency. Integrated injection molding improves the positional accuracy of the transmission points by approximately 67%, enhancing the stability of the closing position and the synchronization of the tripping action. The layered, staggered arrangement of the three transmission columns eliminates motion interference from a mechanistic perspective, reducing the interference jamming rate per 10,000 cycles from 2.8% to 0.4%, and improving operational reliability by approximately 86%. Simultaneously, the stepped clearance design reduces the overall thickness of the mechanism by approximately 15%, validating the advantages of this invention in terms of parts integration, assembly accuracy, motion reliability, and miniaturization adaptability.

Claims

1. A multi-axis layered linkage switch lever for a miniature circuit breaker, characterized in that, include: The lever body is a one-piece molded irregular plate-shaped component, which is divided into an upper linkage area, a middle pivot area and a lower drive arm area along the height direction. The main pivot hole (3) is located in the central pivot area and is used to cooperate with the fixed shaft inside the circuit breaker housing so that the lever body can rotate around the main pivot hole (3). The first lateral transmission column (1) is located in the upper linkage area and extends to one side along the thickness direction of the lever body for cooperating with the circuit breaker handle or the upper linkage component. The second lateral transmission column (2) is located in the central pivot area and maintains a predetermined eccentric distance from the main pivot hole (3) for cooperating with the moving contact frame or the knife block seat. The third lateral transmission column (4) is located in the lower drive arm area and the distance between it and the main pivot hole (3) is greater than the distance between the second lateral transmission column (2) and the main pivot hole (3). It is used to cooperate with the knife gate assembly or the spring mechanism. The first lateral transmission column (1), the second lateral transmission column (2) and the third lateral transmission column (4) are arranged in layers along the height direction of the lever body, and form a stepped outward structure in the thickness direction of the lever body, so that the handle linkage, the guillotine drive and the spring energy storage can be located at different motion levels respectively.

2. The multi-axis layered linkage switch lever for a miniature circuit breaker according to claim 1, characterized in that, The first lateral transmission column (1), the main pivot hole (3) and the second lateral transmission column (2) are arranged in a non-collinear triangular configuration on the lever body, so that the handle input force, pivot support force and guillotine driving force form a stable three-point force system.

3. The multi-axis layered linkage switch lever for a miniature circuit breaker according to claim 2, characterized in that, The main pivot hole (3) is surrounded by an annular bushing reinforcement (31), which protrudes from the surface of the lever body to increase the bearing area of ​​the shaft hole.

4. The multi-axis layered linkage switch lever for a miniature circuit breaker according to claim 3, characterized in that, The lever body is provided with an oblique hook groove (6), which is inclined relative to the length direction of the lever body and is used for hooking the end of the spring, so that the effective lever arm between the elastic element hooked in the oblique hook groove (6) and the main pivot hole (3) changes with the lever angle.

5. The multi-axis layered linkage switch lever for a miniature circuit breaker according to claim 4, characterized in that, The second surface of the lever body is provided with a limiting hook groove (7). The limiting hook groove (7) is located at the edge of the upper linkage area and has a bent or hook-shaped guide profile. The opening direction of the limiting hook groove (7) is adapted to the rotation direction of the lever body. It is used to guide the housing limiting post through the opening during assembly and to form an anti-disengagement limiting through the hook-shaped profile during operation.

6. The multi-axis layered linkage switch lever for a miniature circuit breaker according to claim 5, characterized in that, The lever body has multiple stepped clearance parts (8) on its edge. The stepped clearance parts (8) are matched with the outward extension height of the lateral transmission column in the thickness direction, and are used to avoid adjacent components in the circuit breaker housing during the rotation of the lever.

7. The multi-axis layered linkage switch lever for a miniature circuit breaker according to claim 6, characterized in that, The lever body, the lateral transmission column, the annular bushing reinforcement (31), the oblique hook groove (6), and the limiting hook groove (7) are all integral injection molded structures.

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