An operating mechanism for a miniature circuit breaker

Abstract

The present invention relates to an operating mechanism of a miniature circuit breaker, belonging to the technical field of circuit breakers; it includes a handle, a U-shaped rod, a latch, a support member, an engagement spring, a main spring, and a release lever; the handle is connected to the latch through the U-shaped rod, the latch and the support member form a U-shaped groove, and the middle part of the U-shaped rod is arranged in the U-shaped groove; one end of the latch is adjacent to one end of the release lever, and the other end of the release lever is adjacent to the other end of the support member; one end of the engagement spring is connected to the latch, and the other end is connected to the release lever; a main spring is arranged on the support member. The present invention realizes the reduction of the tripping force by converting the force arm and the force application direction through the latch and the release lever; through the cooperation of the latch, the release lever, the support member and the U-shaped rod, the complete processes of latching, tripping and resetting are completed. The present invention reduces the tripping force of the circuit breaker, improves the sensitivity of the mechanism, reduces the output requirement for the release, and reduces the impact on the product during free tripping.

Description

Technical Field

[0001] The present invention relates to an operating mechanism of a miniature circuit breaker, belonging to the technical field of circuit breakers. Background Art

[0002] The automatic tripping function of a miniature circuit breaker is realized by a free tripping mechanism, and its tripping force is an important technical index of the free tripping mechanism, which should be within a reasonable range. The smaller the tripping force, the more sensitive the mechanism reaction, the lower the requirement for the tripping device, and the smaller the impact on the product during free tripping. For example, in the prior art, a Chinese invention patent with the publication number: CN105742128A and the invention title of "Operating Mechanism of Electrical Protection Device" discloses an operating mechanism of a miniature circuit breaker. In this operating mechanism, when in the closing position, the push rod is located in the opening and closing hole formed by the bracket and the lock. When the mechanism trips, the handle pushes the push rod to slide out of the opening and closing hole into the end slot of the bracket. In this structure, the lock is directly driven by the ejector rod of the electromagnetic tripping device, and at the same time, the lock directly buckles the U-shaped push rod to form a buckling structure. Therefore, the driving of the ejector rod of the tripping device needs to directly face the bracket spring, that is, the acting force of the main spring of the mechanism. Further explanation, the bracket spring directly acts on the bracket, abuts against the U-shaped rod, and the lock locks the U-shaped rod to prevent it from escaping from the opening and closing hole into the end slot of the bracket and tripping. Therefore, the locking force of the lock is relatively large, resulting in a relatively large tripping force, so tripping is more difficult and a tripping device with a larger output force needs to be selected.

[0003] The Chinese invention patent with the publication number: CN103928270A and the invention title of "Operating Mechanism of Miniature Circuit Breaker" discloses a two-stage tripping mechanism, which has a connecting rod, a lever, a tripping latch, a lock, a lever spring, a tripping latch return spring, a lock return spring and a handle return spring. The lever has a limiting effect on the lock. After free tripping, the tripping latch and the lock are reset by their respective return springs, and the direction of the re-latching reset is close to the connection line of the rotation centers of the tripping latch and the lock respectively. There are problems in the technical solution of this document, such as complex structure, many return springs, large return force, and easy reset jamming.

[0004] Therefore, the problem to be solved in this technical field is how to reduce the tripping force of the tripping device, improve the sensitivity of the mechanism, reduce the output requirement for the tripping device, and reduce the impact on the product during free tripping. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problems of reducing the tripping force of the tripping device, improving the sensitivity of the mechanism, reducing the output requirement for the tripping device, and reducing the impact on the product during free tripping.

[0006] To achieve the purpose of solving the above problems, the technical solution adopted by the present invention is to provide an operating mechanism for a miniature circuit breaker, including a handle, a U-shaped rod, a latch, a support, an engagement spring, a main spring, and a tripping rod; the handle is connected to the latch through the U-shaped rod, and a U-shaped groove is formed between one end face of the latch and one end face of the support, and the middle part of the U-shaped rod is arranged in the U-shaped groove; the other end of the latch is adjacent to one end of the tripping rod, and the other end of the tripping rod is adjacent to the other end of the support; a rotating shaft is arranged on the circuit breaker base, and corresponding rotating shaft holes are arranged on the latch, the support, and the tripping rod; one end of the engagement spring is connected to the latch, and the other end is connected to the tripping rod; a main spring is arranged on the support.

[0007] Preferably, a U-shaped groove is formed between one end face of the latch and one end face of the support. The latch end face is sequentially provided with a second contact surface of the latch, a continuous curved surface, and a first contact surface of the latch from the groove opening to the groove bottom; the support is provided with a first contact surface of the support and a second contact surface of the support corresponding to the latch end face; the first contact surfaces of the latch and the support form a first notch structure; the opening of the first notch is smaller than the diameter of the U-shaped rod; a second notch structure is formed between the second contact surface of the latch and the second contact surface of the support, and a protrusion is arranged between the first notch structure and the second notch structure.

[0008] Preferably, the tripping rod is restricted by the support when rotating clockwise; the latch is restricted by the tripping rod when rotating counterclockwise.

[0009] Preferably, when tripping, the support applies a force to move the U-shaped rod towards the notch of the U-shaped groove, and the latch is subjected to a counterclockwise torque of the U-shaped rod.

[0010] Preferably, the contact surface between the tripping rod and the latch adjacent to each other is tangent in the form of an arc, so that the pressure of the latch on the tripping rod passes through the rotation center of the tripping rod.

[0011] Preferably, after the latch and the tripping rod are freely tripped, the reset direction of the latch is away from the connection line direction of the rotation center of the latch and the rotation center of the tripping rod.

[0012] Preferably, when the U-shaped rod is arranged in the second notch structure formed by the latch and the support, the tripping rod is restricted by the latch and cannot be reset; when the U-shaped rod is arranged in the first notch structure of the latch and the support, the tripping rod is reset under the action of the engagement spring.

[0013] Preferably, the force arm l1 of the force of the U-shaped rod on the latch is shorter than the force arm l2 of the supporting force of the tripping rod on the latch; the force arm l3 of the force of the circuit breaker release on the tripping rod is greater than or equal to the force arm l4 of the frictional force of the latch on the tripping rod.

[0014] Preferably, one end of the meshing spring is connected to the latch, and the other end is connected to the release lever; the meshing spring simultaneously provides a clockwise torque restoring force to the latch and the release lever.

[0015] The present invention realizes the reduction of the release force by converting the force arm and the force direction through the latch and the release lever; through the cooperation of the latch, the release lever, the support member and the U-shaped rod, the complete processes of latching, releasing and resetting are completed.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention reduces the release force.

[0018] 2. The present invention improves the sensitivity of the mechanism.

[0019] 3. The present invention reduces the output requirement for the release device

[0020] 4. The present invention reduces the impact on the product during free release. Description of the Drawings

[0021] Figure 1 is the overall structure diagram of the operating mechanism and the release mechanism of the miniature circuit breaker of the present invention;

[0022] Figure 2 is the part drawing of the latch of the release mechanism of the miniature circuit breaker of the present invention;

[0023] Figure 3 is the part drawing of the release lever of the release mechanism of the miniature circuit breaker of the present invention;

[0024] Figure 4 is the part drawing of the support member of the operating mechanism of the miniature circuit breaker of the present invention;

[0025] Figure 5 is the schematic diagram of the frictional resistance of the latch of the miniature circuit breaker of the present invention to the release lever;

[0026] Figure 6 is the schematic diagram of the force exerted by the support member of the miniature circuit breaker of the present invention on the U-shaped rod;

[0027] Figure 7 is the schematic diagram of the force on the latch of the miniature circuit breaker of the present invention;

[0028] Figure 8 is the schematic diagram of the mechanism of the miniature circuit breaker in the open state;

[0029] Figure 9 is the schematic diagram of the mechanism of the miniature circuit breaker at the initial state of release;

[0030] Figure 10 is the schematic diagram of the mechanism of the miniature circuit breaker when the contact system is separated after release;

[0031] Figure 11 It is a schematic diagram of the ejector rod of the miniature circuit breaker trip device of the present invention driving the trip lever;

[0032] Figure 12 It is a schematic diagram of the engagement spring of the miniature circuit breaker of the present invention using a compression spring; Detailed implementation manners

[0033] To make the present invention more obvious and understandable, the preferred embodiments are described in detail below in conjunction with the accompanying drawings:

[0034] Such as Figures 1-12As shown in the figure, the present invention provides an operating mechanism for a miniature circuit breaker, including a handle 1, a U-shaped rod 2, a latch 3, a support member 4, an engagement spring 5, a main spring 6, and a release lever 9; the handle 1 is connected to the latch 3 through the U-shaped rod 2, one end face of the latch 3 and one end face of the support member 4 form a U-shaped groove, and the middle part of the U-shaped rod 2 is installed in the U-shaped groove; the other end of the latch 3 is adjacent to one end of the release lever 9, and the other end of the release lever 9 is adjacent to the other end of the support member 4; a rotating shaft is provided on the circuit breaker base 8, and corresponding rotating shaft holes are provided on the latch 3, the support member 4, and the release lever 9; one end of the engagement spring 5 is connected to the latch 3, and the other end is connected to the release lever 9; a main spring 6 is provided on the support member 4. One end face of the latch 3 and one end face of the support member 4 form a U-shaped groove, and the latch end face is sequentially provided with a second contact surface 32 of the latch, a continuous curved surface 34, and a first contact surface 31 of the latch from the notch to the bottom of the groove; the support member is correspondingly provided with a first contact surface 41 and a second contact surface 42 of the support member for the latch end face; the first contact surfaces 31 and 41 of the latch and the support member form a first notch structure; the opening of the first notch is smaller than the diameter of the U-shaped rod; the second contact surface 32 of the latch and the second contact surface 42 of the support member form a second notch structure, and a protrusion is provided between the first notch structure and the second notch structure. The release lever 9 is restricted by the support member 4 when rotating clockwise; the latch 3 is restricted by the release lever 9 when rotating counterclockwise. The support member 4 provides a force for the U-shaped rod 2 to move towards the notch of the U-shaped groove during tripping, and the latch 3 is subjected to a torque in the counterclockwise direction by the U-shaped rod 2. The contact surface of the release lever 9 adjacent to the latch 3 is tangent in an arc form, so that the pressure of the latch 3 on the release lever 9 passes through the rotation center of the release lever. After the latch 3 and the release lever 9 are freely tripped, the reset direction of the latch 3 is away from the connection line between the rotation center of the latch 3 and the rotation center of the release lever 9. When the U-shaped rod 2 is located in the second notch structure formed by the latch 3 and the support member 4, the release lever 9 is restricted by the latch 3 and cannot be reset; when the U-shaped rod 2 is located in the first notch structure of the latch 3 and the support member 4, the release lever 9 is reset under the action of the engagement spring 5. The force arm l1 of the force of the U-shaped rod 2 on the latch 3 is shorter than the force arm l2 of the supporting force of the release lever 9 on the latch 3; the force arm l3 of the force of the circuit breaker release 7 on the release lever 9 is greater than or equal to the force arm l4 of the frictional force of the latch 3 on the release lever 9. One end of the engagement spring 5 is connected to the latch 3, and the other end is connected to the release lever 9; the engagement spring 5 simultaneously provides a clockwise torque reset force for the latch 3 and the release lever 9.

[0035] As Figures 1-12As shown in the figure, F1 is the thrust of the U-shaped rod 2 on the latch 3, and the lever arm is l1, which causes the latch 3 to generate a counterclockwise torque; Fn is the supporting force of the release lever 9 on the latch 3, and the lever arm is l2, which causes the latch 3 to generate a clockwise torque; F3 is the thrust of the ejector rod of the release 7 on the release lever 9, and the lever arm is l3, which causes the release lever 9 to generate a counterclockwise torque; f is the frictional resistance of the latch 3 on the release lever 9, and the lever arm is l4, which causes the release lever 9 to generate a clockwise torque; F5 is the thrust of the support 4 on the U-shaped rod. The support 4 contacts one end of the U-shaped rod 2 and provides pressure, causing the U-shaped rod 2 to tend to escape outward, that is, a counterclockwise torque.

[0036] As Figure 1 shown in the figure, the handle 1 and the support 4 are installed on the base 8 through hole-shaft fit. One end of the U-shaped rod 2 contacts the support 4 and the latch 3, and the other end is installed on the handle 1 through hole-shaft fit. The handle 1, the support 4, the U-shaped rod 2, the latch 3, and the release lever 9 form a linkage mechanism.

[0037] As Figure 1 and Figure 2, the latch 3 is pivotally connected to the rotating shaft 101. The engagement spring 5 is also sleeved on the shaft 101, with one end abutted against the latch 3 and the other end abutted against the release lever 9. The latch 3 is further provided with the following structure: a first contact surface 31, which contacts one end of the U-shaped rod 2. The latch 3 is biased clockwise by the spring force of the engagement spring 5, so that the latch 3 contacts and abuts against the U-shaped rod 2. When the circuit breaker is tripped, the U-shaped rod 2 moves towards the outside of the notch. Under the push of the U-shaped rod 2, the latch 3 has a tendency to move counterclockwise, that is, a tendency to release; the latch 3 is further provided with a second contact surface 32. When the second contact surface 32 contacts one end of the U-shaped rod 2, the latch 3 cannot be reset before the U-shaped rod 2 returns to the position of the first contact surface 31; the first contact surface 31 has a continuous curved surface, and this curved surface is designed such that the torque formed by the thrust F1 of the U-shaped rod 2 on the latch 3 has a smaller force arm l1, which is shorter than the force arm l2 of the supporting force of the release lever 9 on the latch 3, that is, l1 < l2. The continuous curved surface of the first contact surface 31 can be designed as an arc-shaped curved surface, an elliptical curved surface, etc., so that no matter which point on the contact surface the U-shaped rod 2 acts on the latch 3, it has a smaller force arm l1. After tripping, the operating mechanism acts, so that the U-shaped rod 2 moves from the first contact surface 31 of the latch 3 to the second contact surface 32 of the latch 3. Therefore, a continuous curved surface 34 is designed at the boundary where the two contact surfaces meet, so that the first contact surface 31 to the second contact surface 32 are all continuous and there are no singularities, so that when tripping and opening the circuit breaker, the movement of the U-shaped rod 2 is kept smooth. In addition, in the closed state of the contact system, and when not tripping and opening the circuit breaker, that is, when the normal operating handle disconnects the contact system, the latch 3 and the release lever 9 do not trip. The continuous curved surface 34 has a slightly convex structure to maintain a certain tripping force threshold and prevent the risk of slipping between the latch 3 and the release lever 9, that is, when the U-shaped rod 2 is driven by the handle 1 and one end thereof returns from the contact surface 32 of the latch 3 to the contact surface 31 of the latch 3, due to the existence of the protrusion 34, the U-shaped rod 2 and the latch 3 are interlocked with each other, and the tripping mechanism maintains a certain tripping force and will not slip due to vibration. When the U-shaped rod 2 continues to move towards the outside of the notch and crosses the protrusion 34, the tripping force is further reduced.

[0038] The latch 3 is further provided with a contact surface 33 that contacts the release lever 9. The contact surface is a third contact surface 33 of the latch in the shape of an arc. A groove 35 is further provided on its inner side. The existence of the groove 35 provides a margin for buckling for the contact surface 33 between the latch 3 and the release lever 9. In this way, when the buckling depth between the latch 3 and the release lever 9 becomes larger due to long-term operation or component tolerance problems, the third contact surface 33 always remains in contact with the release lever 9, so that the two always contact in a tangential linear contact form. The force arm l1 of the acting force F1 of the U-shaped rod 2 on the latch 3 is shorter than the force arm l2 of the supporting force Fn of the release lever 9 on the latch 3, so that the supporting force Fn of the release lever 9 on the latch 3 is less than the acting force F1 of the U-shaped rod 2 on the latch 3, that is, the normal pressure of the latch on the release lever 9 is reduced, and the function of reducing the tripping force is achieved.

[0039] The spring 6 is the main spring of the operating mechanism, which enables the support member 4 to exert a thrust F5 on the U-shaped rod 2. Through the force transmission, the U-shaped rod 2 generates a thrust F1 on the latch 3, causing the latch 3 to generate a counterclockwise torque. Due to the supporting force Fn of the release lever 9 on the latch 3, the latch 3 generates a clockwise torque. The torque balance keeps the latch 3 in a static state. Since the U-shaped rod 2 is restricted by the handle 1 in the degree of freedom in the distal direction, once the contact support between the latch 3 and the release lever 9 is lost, under the action of the thrust F5, the U-shaped rod 2 has a tendency to move towards the notch direction, that is, the U-shaped rod 2 has a tendency to move towards the second contact surface 32 of the latch. However, due to the latch 3 being in a static locked state, the tendency of the U-shaped rod 2 to move towards the notch direction is restricted, and the whole mechanism is in a steady state.

[0040] The release lever 9 is pivotally connected to the rotating shaft 102 and has a first mating surface 91 of the support member that abuts against the mating surface 43 of the support member 4. The release lever 9 is restricted by the support member 4 in the clockwise movement direction to prevent the release lever 9 from rotating clockwise excessively, causing the contact position between the latch 3 and the release lever 9 to be too deep, or being latched too tightly and affecting the release.

[0041] The release lever 9 is provided with a second mating surface 92 that is pushed by the ejector rod of the circuit breaker release 7. When a short-circuit current occurs, the ejector rod of the release 7 pushes the release lever 9 to rotate counterclockwise around the shaft 102, causing the latch 3 and the release lever 9 to be released, unlocking the steady state of the operating mechanism and disconnecting the contact system.

[0042] The contact surface 93 of the release lever 9 that contacts the third contact surface 33 of the latch 3 is an arc surface, and the center of the arc surface is the rotation center of the release lever 9; the force arm l3 of the force F3 exerted by the release 7 on the release lever 9 is not less than the force arm l4 of the friction force f of the latch 3 on the release lever 9, which functions to reduce the acting force; the release 7 pushing the release lever 9 to rotate is actually a process of overcoming the meshing spring force and the friction force of the latch 3 on the release lever 9. In addition, since both the third contact surface 33 of the latch 3 and the contact surface 93 of the release lever 9 are arc surfaces, and the arc surface of the contact surface 93 is centered on the rotating shaft 102, the pressure of the third contact surface 33 of the latch 3 on the contact surface 93 of the release lever 9, that is, the pressure of the latch 3 on the release lever 9, passes through the center of the rotating shaft 102. Therefore, the pressure only affects the friction force between the two contact surfaces and will not generate a component force that causes the release lever 9 to rotate clockwise or counterclockwise, and this is the case at any contact position of the two contact surfaces. With the two cases of reducing the acting force, the actual release force, that is, the force exerted by the release 7 on the release lever 9, will be greatly reduced.

[0043] The support member 4 is pivotally connected to the rotating shaft 103 and has a mating surface 43 of the support member 4 that abuts against the first mating surface 91 of the release lever 9, providing a limit for the release lever 9; a first contact surface 41 of the support member 4 that contacts the U-shaped lever 2 and mates with the first contact surface 31 of the latch 3, causing the latch 3 to be held in the reset position, i.e., the latched position; a second contact surface 42 of the support member 4 that contacts the U-shaped lever 2 and mates with the second contact surface 32 of the latch 3, i.e., when the U-shaped lever 2 moves towards the notch, the second contact surface 42 of the support member 4 provides support for the U-shaped lever 2, causing the latch 3 to be pushed by the U-shaped lever 2 and rotate counterclockwise.

[0044] One end of the engagement spring 5 abuts against the latch 3, providing a clockwise torque to the latch 3 so that after free tripping, the latch 3 can be normally reset; the other end abuts against the release lever 9, providing a clockwise torque to the release lever 9 so that under normal circumstances, the release lever 9 presses on the support member 4, and in addition, after free tripping, the release lever 9 can be normally reset. That is, when the short-circuit current in the circuit is cut off, the ejector rod 71 of the release 7 resets and retracts, and the engagement spring 5 causes the latch 3 and the release lever 9 to rotate clockwise. Due to the limiting effect of the mating surface 43 of the support member 4, the release lever 9 is stabilized in the corresponding position, and the clockwise rotation of the latch 3 causes it to latch onto the release lever 9 again.

[0045] The working process of the embodiment of the present invention:

[0046] In the closed state, under the action of the engagement spring 5, the mating surface 91 of the release lever 9 presses on the mating surface 43 of the support member 4, and the release lever 9 is restricted by the support member 4 in the clockwise direction and cannot continue to rotate; the first contact surface 31 of the latch 3 and the first contact surface 41 of the support member 4 cooperate to form a first notch, and the opening of the first notch is smaller than the diameter of the U-shaped lever 2, restricting one end of the U-shaped lever 2 inside. Under the spring force of the main spring 6, the support member 4 contacts one end of the U-shaped lever 2 and provides pressure, causing the U-shaped lever 2 to tend to move towards the notch. The U-shaped lever 2 is also latched by the latch 3 and cannot move. The U-shaped lever 2 has a counterclockwise torque effect on the latch 3, and the counterclockwise rotation of the latch 3 is restricted by the release lever 9, thus forming a balance.

[0047] When the driving handle 1 makes a clockwise movement towards the U-shaped lever 2 for normal disconnection, the U-shaped lever 2 pulls the latch 3 to rotate counterclockwise. Since the latch 3 and the release lever 9 are always in the latched position, the release lever 9 is driven to move counterclockwise together. At this time, the support member 4 will also rotate counterclockwise under the push of the main spring 6, thereby disconnecting the contact system.

[0048] When an overcurrent occurs in the circuit, the electromagnetic release 7 operates. Its ejector rod 71 pushes the release lever 9 to rotate counterclockwise by a certain angle against the acting force of the engagement spring 5. After that, the locking latch 3 and the release lever 9 are disengaged. The rotation of the locking latch 3 in the counterclockwise direction is not restricted, and the balance is broken. At this time, under the spring force of the main spring 6, the support 4 rotates counterclockwise, pushing the U-shaped rod 2 to move. The locking latch 3 is pushed by the U-shaped rod 2 and rotates counterclockwise. The U-shaped rod 2 slides out of the first notch and reaches the second notch formed by the cooperation of the second contact surface 32 of the locking latch 3 and the second contact surface 42 of the support 4 and continues to move towards the notch until the free tripping action is completed. During this process, the engagement spring 5 is compressed to prepare for the reset of the locking latch 3 and the release lever 9.

[0049] After the free tripping of the U-shaped rod 2, restricted by the second contact surface 32 of the locking latch 3 and the second contact surface 42 of the support 4, under the action of the torsion spring of the handle 1, the handle 1 rotates clockwise towards the direction close to the U-shaped rod 2, driving the U-shaped rod 2 to move towards the bottom of the notch, so that the U-shaped rod 2 returns from the second notch formed between the second contact surface 32 of the locking latch 3 and the second contact surface 42 of the support 4 to the first notch formed between the first contact surface 31 of the locking latch 3 and the first contact surface 41 of the support. When the U-shaped rod 2 is located in the second notch, the locking latch 3 cannot be reset, and the release lever 9 is restricted by the support 4 and cannot be reset; when the U-shaped rod 2 returns from the second notch to the first notch, the support 4 also rotates counterclockwise, and the release lever 9 is reset to the latched position under the action of the engagement spring 5, and the locking latch 3 is also reset to the latched position under the action of the engagement spring 5. In this way, the locking latch 3 and the release lever 9 are restored to the latched state, and the operating mechanism returns to the steady state. The clockwise rotation of the locking latch 3 makes its reset direction away from the connection line between the rotation centers of the locking latch 3 and the release lever 9. In this way, even due to component tolerances and installation errors, during the reset process, if there is contact between the mating surfaces of the locking latch 3 and the release lever 9, the tendency of the two to expand outwards will not cause jamming, ensuring smooth reclosing.

[0050] In addition, due to the adoption of a multi-stage tripping structure and a special design of the tripping mechanism in the tripping mechanism of the present invention, the tripping force is greatly reduced and there is no risk of slipping of the buckle. Therefore, there is still surplus driving force of the ejector rod of the original specification electromagnetic release. In the present invention, a boss 72 is provided at the ejector rod 71 of the release 7. The boss 72 can be a disc with a diameter larger than that of the ejector rod 71, which can simultaneously push the moving contact bracket 11 of each pole contact system of the two-pole circuit breaker. The boss 72 is located behind the end of the ejector rod 71. When a short-circuit current occurs, the electromagnetic release 7 operates. The ejector rod 71 first pushes the tripping rod 9 to operate, and the lock 3 and the tripping rod 9 are tripped and separated. At this time, the boss 72 just touches the moving contact bracket 11 and acts together with the main spring 6 to disconnect the contact system. Of course, it can also be designed in a non-disc form as long as it can push the moving contact bracket 11. After the driving force of the ejector rod 71 causes the tripping mechanism to trip freely, it pushes the moving contact bracket 11, so that the moving contact obtains a greater initial velocity of counterclockwise rotation and the breaking capacity is improved.

[0051] The above are only the preferred embodiments of the present invention, and do not impose any formal or substantial limitations on the present invention. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the premise of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any equivalent changes, modifications and evolutions made by those skilled in the art who are familiar with this specialty without departing from the spirit and scope of the present invention by using the technical content disclosed above are equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments according to the substantial technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An operating mechanism for a miniature circuit breaker, characterized in that: It includes a handle, a U-shaped rod, a lock catch, a support member, an engagement spring, a main spring and a release lever; the handle is connected to the lock catch through the U-shaped rod, one end face of the lock catch and one end face of the support member form a U-shaped groove, and the middle part of the U-shaped rod is arranged in the U-shaped groove; the other end of the lock catch is adjacent to one end of the release lever, and the other end of the release lever is adjacent to the other end of the support member; a rotating shaft is arranged on the circuit breaker base, and corresponding rotating shaft holes are arranged on the lock catch, the support member and the release lever; one end of the engagement spring is connected to the lock catch, and the other end is connected to the release lever; a main spring is arranged on the support member; one end face of the lock catch and one end face of the support member form a U-shaped groove, and the lock catch end face is sequentially provided with a second contact surface of the lock catch, a continuous curved surface and a first contact surface of the lock catch from the groove opening to the groove bottom; the support member is correspondingly provided with a first contact surface of the support member and a second contact surface of the support member opposite to the lock catch end face; the first contact surfaces of the lock catch and the support member form a first notch structure; the opening of the first notch is smaller than the diameter of the U-shaped rod; the second contact surface of the lock catch and the second contact surface of the support member form a second notch structure, and a protrusion is arranged between the first notch structure and the second notch structure; the continuous curved surface has a micro-protrusion structure to maintain a certain release force threshold and prevent the lock catch and the release lever from slipping.

2. The operating mechanism of a miniature circuit breaker according to claim 1, characterized in that: The release lever is restricted by the support member when rotating clockwise; the lock catch is restricted by the release lever when rotating counterclockwise.

3. The operating mechanism of a miniature circuit breaker according to claim 1, characterized in that: The support member provides a force for the U-shaped rod to move towards the notch of the U-shaped groove during release, and the lock catch is subjected to a torque in the counterclockwise direction by the U-shaped rod.

4. The operating mechanism of a miniature circuit breaker according to claim 1, characterized in that: The contact surface of the release lever adjacent to the lock catch is tangent in an arc form, so that the pressure of the lock catch on the release lever passes through the rotation center of the release lever.

5. The operating mechanism of a miniature circuit breaker according to claim 1, characterized in that: After the lock catch and the release lever are freely released, the reset direction of the lock catch is away from the connection line direction of the rotation center of the lock catch and the rotation center of the release lever.

6. The operating mechanism of a miniature circuit breaker according to claim 1, characterized in that: When the U-shaped rod is arranged in the second notch structure formed by the lock catch and the support member, the release lever is restricted by the lock catch and cannot be reset; when the U-shaped rod is arranged in the first notch structure of the lock catch and the support member, the release lever is reset under the action of the engagement spring.

7. The operating mechanism of a miniature circuit breaker according to claim 1, characterized in that: The force arm l1 of the force of the U-shaped rod on the lock catch is shorter than the force arm l2 of the supporting force of the release lever on the lock catch; the force arm l3 of the force of the circuit breaker release on the release lever is greater than or equal to the force arm l4 of the frictional force of the lock catch on the release lever.

8. The operating mechanism of a miniature circuit breaker according to claim 1, characterized in that: One end of the engagement spring is connected to the lock catch, and the other end is connected to the release lever; the engagement spring simultaneously provides a clockwise torque reset force for the lock catch and the release lever.

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