JPH05144365A - Circuit breaker - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the breaking performance by increasing the opening distance of the movable contact for the movement of the operating handle. [Structure] A holder 6 holding a movable contact 9 is rotatably engaged with a latch pin 15 fixed to a main body case 1 at an end opposite to the movable contact 9, and one end 4a is connected to an operation handle 2. The other end 4b of the link 4 is connected to the holder 6 between the movable contact 9 and the latch pin 15. As a result, the movable contact 1 is also longer than the arm length from the rotation fulcrum 15 of the holder 6 to the connection point 4b between the link 4 and the holder 6.
Since the length of the arm up to 3 is longer, the movement of the operation handle 2 is enlarged, and the separation distance of the movable contact 13 for the same operation stroke is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-voltage circuit breaker used for protecting electric circuits of various machines, and more particularly to an opening / closing mechanism thereof.

[0002]

2. Description of the Related Art As a circuit breaker of this type, Japanese Patent Publication 1-
The one described in Japanese Patent No. 55742 is known. This circuit breaker has one end rotatably connected to an operation handle, which forms a toggle link mechanism together with the operation handle, a roller rotatably provided at the other end of the link, and a rotatably pivoting member. The movable contact has a latching surface that is supported at one of the rotating ends and that faces the roller, and that the other rotating end has a movable contact that faces the fixed contact. A mover urged in a direction of separating from the fixed contact, rotatably supported by the mover, and disposed at a rotating end so as to face the latch surface and constantly urged in the latch surface direction. A locking lever having a locked portion and an overcurrent and overcurrent trip device that operates the locking lever when an overcurrent of a predetermined value or more flows, and the roller is normally provided with the latch surface and the latch surface. It is clamped by the locking part to operate the above operation handle. When the contacts are separated from each other and an overcurrent of a predetermined value or more flows, the overcurrent and overcurrent trip device operates the locking lever to open the contacts so that the pinching is released. It is a thing.

[0003]

However, the above circuit breaker has the following problems. (1) A link for opening and closing the mover is connected to a rotating end opposite to the movable contact with an axis rotatably supporting the mover interposed therebetween. Therefore, the separation distance of the movable contact from the fixed contact is suppressed to the same extent as the displacement of the link due to the opening / closing operation of the operation handle, and this aspect limits the breaking performance.

(2) The mover is held together with the operation handle by a link forming a toggle link mechanism to hold the reset state. Therefore, there is a great risk that the above-mentioned locking will be released due to the vibration of the link accompanying the reversal of the toggle link mechanism at the time of the ON operation, and a mistrip will occur. This invention makes it possible to obtain a large separation distance as compared with the displacement of the link due to the operation of the operation handle, and is less susceptible to the vibration of the link at the time of the ON operation to improve the breaking performance and stabilize the operation. A first object of the present invention is to provide a circuit breaker aiming at the above.

Further, in the above circuit breaker, the engagement between the mover and the roller of the link that locks the mover is always held by the spring-biased lock lever, and the lock lever is excessive during trip. The current overcurrent trip device is rotated against the spring force to unlock the mover. In that case, it is preferable that the torque acting on the locking lever based on the spring bias is as small as possible because the trip load that the overcurrent trip device bears is small.
However, when this torque is reduced, the mover is not sufficiently locked, and a mistrip easily occurs.

On the other hand, the mistrip is a circuit breaker OFF.
It is more likely to occur during ON operation than during operation. That is O
During N operation, a larger operating force is applied to the engaging portion between the mover and the roller during the N operation than in the OFF operation, and the mover collides with the stator at the moment of the ON operation and vibrates. Is caused by. Taking these into consideration, the torque acting on the locking lever is O of the circuit breaker.
In the N state, it is desirable to make it as small as possible within the range where no mistrip occurs, and as large as possible in the OFF state irrelevant to trip load. Therefore, the present invention provides a circuit breaker in which the torque acting on the locking lever based on the spring bias is changed according to the state of the circuit breaker to reduce the risk of mistrip without increasing the trip load. It is the second purpose.

Further, in a circuit breaker of this type, generally, when a trip operation is performed, the operation handle shifts from the ON position to the OFF position, so whether the circuit breaker is in the OFF state or the trip state from the stop position of the operation handle. I can't tell. Therefore, a third object of the present invention is to provide a circuit breaker capable of discriminating between the OFF state and the trip state from the stop position of the operation handle.

[0008]

In order to achieve the first object, the circuit breaker of the present invention comprises a latch pin fixed to the main body case and a latch surface at one end which engages with the latch pin. A holder that has a movable contact at the other end and that rotates and opens and closes the movable contact by using the latch pin as a fulcrum, and a holder that is rotatably supported by this holder and that is always covered by the latch pin. And the latch surface are kept engaged, and when an overcurrent occurs, a locking lever that is rotated by the action of an overcurrent trip device to release the engagement, and is rotatable with respect to the main body case. A supported operation handle, one end of which is connected to the operation handle and the other end of which is connected to the holder between the latch surface and the movable contact, and the movable contact is opposed to the link. Shall and a cutoff spring for urging the holder in the direction separates from the fixed contact to.

In order to achieve the second object,
According to the present invention, in the circuit breaker, the torque acting on the locking lever based on the spring force is OFF rather than the ON state.
It shall be configured so that the state becomes larger. Furthermore, in order to achieve the above-mentioned third object, the present invention is such that, in the above-mentioned circuit breaker, it is fixed to the main body case,
A trip display spring that interferes with the connecting shaft between the holder and the link that moves during a trip to stop the movement in the middle of the trip, and at the time of resetting, elastically deforms due to the manual operation force acting on the operation handle and passes through the connecting shaft. Shall be provided.

[0010]

According to the present invention, the link for transmitting the movement of the operation handle to the holder is connected to the holder between the latch pin which serves as the fulcrum of rotation of the holder and the movable contactor at the opposite end thereof. Therefore, the arm length from the latch pin to the movable contact is necessarily larger than the arm length from the latch pin to the link connection point, and the displacement of the movable contact is relative to the displacement of the link by the lever ratio. It is enlarged and a large opening distance is obtained.

Further, since the latch surface and the latch pin fixed to the main body case are engaged to hold the opening / closing mechanism in the set state, the vibration of the link at the time of ON operation directly affects the locking of the holder. Moreover, there is no risk of the generation of mistrip. In that case, if the torque generated by the spring for urging the locking lever is set to be larger in the OFF state than in the ON state, the torque is suppressed to an extent that does not cause a mistrip in the ON state, and the trip load becomes excessive. In the OFF state, the torque can be sufficiently increased without considering the trip load while preventing the occurrence of the risk, and the danger of the miss lip during the ON operation can be eliminated.

In the above circuit breaker, when the locking lever is disengaged from the latch pin at the time of trip and the latch pin is disengaged from the latch surface of the holder, the holder is rotated by the force of the breaking spring to move the movable contact. At the time of opening, the operation handle is reversed from the ON position to the OFF position by the reset spring mounted between the operation handle and the link connected to the operation handle, and accordingly, the link shaft between the link and the holder. Moves along a fixed trajectory.

Therefore, a trip indicating spring that interferes with the connecting shaft is provided, and its movement is stopped midway to stop the operating handle between the ON position and the OFF position so that a trip state is reached from the stop position of the operating handle. To be able to judge. In this state, in order to reset the engagement between the latch pin and the latch surface of the holder, the operation handle must be manually moved to the OFF position. For that purpose, the trip indicator spring acts via the connecting shaft. It is elastically deformed by the manual operation force of the operation handle to pass through the connecting shaft.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First Embodiment First, FIGS. 1 to 4 show a first embodiment of the present invention. Here, FIG. 1 is an ON state, FIG. 2 is an OFF state, and FIG.
2 is a vertical cross-sectional view of the circuit breaker showing respective states at the moment of tripping, and FIG. 4 is an exploded perspective view of essential components in FIG. In these figures, an operation handle 2 is rotatably supported by a shaft 3 on a main body case 1 made of molded resin, and one of the U-shaped links 4 is provided in a connecting hole 5 (FIG. 4) of an arm 2a thereof. The leg 4a is inserted. Further, the other leg 4b of the link 4 is inserted into a connecting hole 7 (FIG. 4) provided at substantially the center of the holder 6 having a U-shaped cross section. An inverted trapezoidal groove-shaped latch surface 6a is provided at one end of the holder 6.
(FIGS. 3 and 4), and a V-shaped groove 6b (FIG. 4) is formed at the other end.

The link 4 inserted in the connecting hole 7 of the holder 6
The leg 4b is also inserted into the fulcrum hole 8c (FIG. 4) of the locking lever 8 so that the locking lever 8 is rotatably supported inside the holder 6. Arms 9a (FIG. 4) on both sides of the movable contactor 9 are fitted in the groove 6b of the holder 6, and the movable contactor 9 is passed through the window hole 10 of the U-bent portion of the holder 6 and the cutoff spring 11 formed of a tension coil spring. One end of is hung. The other end of the cutoff spring 11 is hooked on a pin 12 fixed to the main body case 1, and the cutoff spring 11 holds the movable contactor 9 toward the holder 6 side so as not to fall off. A movable contact 13 is attached to the tip of the movable contactor 9 which is bent in an S shape.

A reset spring 14 composed of a torsion spring is inserted in the leg 4a of the link 4, one end 14a of the reset spring 14 is on the outer periphery of the boss portion 2b of the operating handle 2, and the other end 14b is of the link 4. It is hung on the leg 4b. The reset spring 14 acts so as to rotate the holder 6 counterclockwise in FIG. 1 about the leg 4a via the leg 4b of the link 4, and in response to this action, the latch surface 6a of the holder 6 is rotated.
Is pressed against the latch pin 15 fixed to the body case 1.

As shown in FIGS. 1 and 2, the latch surface 6a is normally (when ON and OFF) the latch pin 1
The roller 16 engaged with the latch pin 5 and loosely fitted into the latch pin 15 is covered with an engaging portion 8 a formed by bending the tip of the engaging lever 8 inside the holder 6. Also,
The locking lever 8 is attracted to the latch pin 15 side by a return spring 17 which is a tension coil spring provided between the locking lever 8 and the holder 6.

A hook 8b is integrally provided on one side near the tip of the locking lever 8, and a trip arm 19a formed integrally with an armature 19 of an overcurrent trip device 18 is engaged with the hook 8b. It is supposed to meet. The armature 19 is rotatably supported by an L-shaped yoke 20 via a pin 21, and when an overcurrent flows through the trip coil 22, it is attracted to the armature 24 against the return spring 23. One end of the trip coil 22 is connected to a fixed contact 25 fixed to the main body case 1, and the other end is connected to a load side terminal plate 26. A fixed contact 27 is attached to the fixed contact 25 so as to face the movable contact 13. The movable contact 9 is connected to a terminal plate 29 on the power source side via a flexible conductor 28.

In such a structure, when the handle 2c of the operating handle 2 is tilted to the opposite side against the blocking spring 11 from the OFF state of FIG. 2, the holder 6 receives a force from the arm 2a via the link 4. , Is rotated counterclockwise about the latch pin 15 to bring the movable contact 13 into contact with the fixed contact 27. In the meantime, the blocking spring 11 is stretched and stores energy. When the movable contact 13 hits the fixed contact 27, the movable contact 9 is slightly rotated in the clockwise direction in the figure against the blocking spring 11 and a proper contact pressure is applied. When the toggle link mechanism formed by the arm portion 2a of the operating handle 2 and the link 4 exceeds the dead point in the above process, the force of the shutoff spring 11 on the operating handle 2 is reversed, and the operating handle 2
Is held in the ON state in FIG. In this state, the electric current is terminal plate 29-flexible conductor 28-movable contact 9-movable contact 13
-Fixed contact 27-fixed contact 25-tripping coil 22-
It flows in the path of the terminal board 26.

In the ON state of FIG. 1, the holder 6 receives a force from the breaking spring 11 in the clockwise direction centering on the leg 4b of the link 4, and the latch surface 6a (FIG. 4) tries to come off from the latch pin 15. Since the latch pin 15 is covered with the locking portion 8a of the locking lever 8, the holder 6 cannot be moved and is kept in the illustrated state. On the other hand, the locking lever 8 receives a reaction force from the latch pin 15, but the force acting on the locking portion 8a is set so that the line of action passes through the leg 4b of the link 4 which is the pivotal fulcrum of the locking lever 8. Therefore, it does not act as a turning force, and the locking portion 8a does not come off from the latch pin 15.

In the ON state of FIG. 1, when an overload current or a short-circuit current flows in the current path and the overcurrent trip device 18 operates, the attracted armature 19 rotates clockwise in the figure to trip. The locking lever 8 is rotated around the leg 4b in the same direction via the arm 19a. As a result, the locking portion 8a is disengaged from the latch pin 15, and the holder 6 released from the restraint is actuated by the blocking spring 11 to move the latch surface 6a.
Is disengaged from the latch pin 15, and the arcuate end portion 6c slips under the latch pin 15 and rotates until the corner portion 6d at the opposite end contacts the inner wall surface of the main body case 1 (trip operation). FIG. 3 shows that moment, whereby the movable contact 13 is rapidly separated from the fixed contact 27 to interrupt the current. An arc-shaped beak-shaped portion 6e is provided on the outer side of the end surface 6c of the holder 6 so as to sandwich the latch pin 15 loosely. This is for guiding the above-described rotation of the holder 6 during a trip operation. Not necessarily required.

When the holder 6 is rotated to the state shown in FIG. 3 by the above-mentioned trip operation, the reset spring 14 which has been stored until then is returned to its original shape and the operation handle 2 is rotated clockwise (OFF direction) in the figure. To move. And the arm 2a
When the toggle link mechanism composed of the link 4 and the link 4 exceeds the dead point, the breaking spring 11 pulls up the holder 6 counterclockwise in the drawing with the contact point between the corner 6d and the main body case 1 as a fulcrum, and the latch surface is pulled. 6a is again engaged with the latch pin 15 (reset operation). At that time, trip coil 2
The excitation of No. 2 is released, and the armature 19, and hence the locking lever 8 is returned, and returns to the same state as the OFF state of FIG. 2 as a whole.

In the illustrated structure, the link 4 for transmitting the movement of the operation handle 2 to the holder 6 includes the latch pin 15 as a fulcrum of rotation of the holder 6 and the movable contactor 9 at the opposite end thereof.
Is connected to the holder 6 between. Therefore, FIG.
At the connection point of the link from the latch pin 15 (leg 4
The arm length R from the latch pin 15 to the movable contact 13 becomes larger than the arm length r up to b), and the displacement of the movable contact 13 becomes the displacement of the link 4 by the lever ratio R / r. In contrast, it has been expanded, and a large opening distance has been obtained.

Further, since the latch surface 6a is engaged not with the link 4 but with the latch pin 15 fixed to the main body case 1, the vibration of the link 4 when the operation handle 2 is turned on directly affects the locking of the holder 6. There is no influence, and there is no risk that the latch surface 6a is accidentally disengaged from the latch pin 15 and a mistrip occurs. Further, in the illustrated embodiment, one end of the breaking spring 11 is hooked on the movable contactor 9 rotatably held by the holder 6, and the spring force of the breaking spring 11 acts on the holder 6 via the movable contactor 9. Therefore, the breaking spring 11 also has a function as a contact spring of the movable contactor 9, and a separate contact spring between the holder 6 and the movable contactor 9 is not necessary.

Second Embodiment Next, FIGS. 5 to 7 show a second embodiment of the present invention, FIG. 7 is a longitudinal sectional view of the circuit breaker in an ON state, and FIG. 6 is an exploded view of essential components in FIG. A perspective view, FIG. 7A is an enlarged view of the ON state of the operating mechanism portion of FIG. 5, and FIG. 7B is the same OFF state.
It is an enlarged view of a state. The main differences between the second embodiment and the first embodiment are that the directions of ON and OFF operations of the operation handle 2 are reversed, and that the return spring 17 is composed of a torsion spring. In the second embodiment, although not directly related to the purpose and effect of the present invention, two frames 30 on the left and right (only one side is shown in the drawing) for convenience of assembly work.
3, a shaft 3 for supporting the operation handle 2, a shutoff spring 1
Pin 12 and latch pin 15 to hang this frame 3
It is fixed to 0.

The return spring 17 has a spiral winding portion inserted into the leg 4a of the link 4, and one end 17a thereof is hooked on the outer periphery of the boss portion 2b of the operation handle 2. Further, as shown in FIG. 6, the locking lever 8 is provided with a spring hooking portion 8d at the end opposite to the locking portion 8a with a fulcrum hole 8c through which the leg 4b of the link 4 serving as the rotating shaft passes. The other end 17b of the return spring 17 that is bent in a hook shape is hung on the return spring 17. As a result, as can be seen from FIG. 7, the locking lever 8 receives a counterclockwise torque from the return spring 17 around the fulcrum shaft 4b, and the locking portion 8a is attracted to the roller 16.

In such a configuration, FIG. 5 and FIG.
When the handle 2c of the operation handle 2 is tilted counterclockwise from the ON state of (A), the arm 2a of the operation handle 2 and the link 4 are
When the toggle link mechanism consisting of and exceeds the dead point, the holder 6 is pulled up by the breaking spring 11 in the tensioned state and rotates clockwise around the latch pin 15 as a fulcrum, and the corner portion 6d stops the frame 30 as a stopper. It stops at the position where it hits the portion 30a. As a result, the movable contact 13 is separated from the fixed contact 27. FIG. 7B shows such an OFF state.

Now, comparing the ON state of FIG. 7A and the OFF state of FIG. 7B, the opening angle of the return spring 17 of the locking lever 8 is B when A (ON state). The spring force of the return spring 17, which is a torsion spring, is larger than that in the (OFF state), and is 0 in the OFF state where the opening angle is small.
It is larger than the N state. Moreover, the length of the arm from the point of action of the spring force to the center of the leg 4b is smaller in L ₁ (ON state) than in L ₂ (OFF state).

Therefore, the counterclockwise torque (product of spring force and arm length) acting on the locking lever 8 based on the spring force of the return spring 17 is larger in the OFF state than in the ON state. There is. As a result, in order to prevent the trip load (the torque for rotating the locking lever 8 in the clockwise direction in the overcurrent and overcurrent trip device 18) from becoming excessive, the torque of the reset spring 14 in the ON state is generated by the miss lip. Even if the lock lever 8 is set as small as possible without a limit, a larger torque, for example, twice or more torque can be applied to the locking lever 8 in the OFF state, and the locking lever 8 is generated during the ON operation in which a miss lip is likely to occur. Can be sufficiently attracted to the roller 16 side to prevent the mistrip. The other operations and actions are the same as those in the first embodiment, and the description thereof will be omitted.

Embodiment 3 FIGS. 8 to 10 show Embodiment 3 of the present invention, FIG. 8 is a vertical cross-sectional view of a circuit breaker in an ON state, and FIG. 9 is an exploded perspective view of essential components in FIG. 10A is an enlarged view of the ON state of the operation mechanism portion of FIG. 8, and FIG. 10B is an enlarged view of the OFF state thereof. Similarly to the second embodiment, the third embodiment is configured such that the torque acting on the locking lever 8 is larger in the OFF state than in the ON state. The difference from the third embodiment is that a tension spring is used as a return spring. Is the point using.

That is, in this case, a spring hooking hole 4c is provided in a part of the link 4, and one end 17a of a return spring 17 made of a tension spring is hooked in this hole, and the other end 17b.
Is hung on the groove 8e of the locking lever 8. Here, comparing the ON state of (A) and the OFF state of (B) of FIG. 10, the tension length of the return spring 17 is slightly shorter in B (OFF state) than in A (ON state). The influence is small, and the length L of the arm from the point of application of the spring force to the center of the leg 4b is L.
_{Since 2} (OFF state) is larger than L ₁ (ON state), the torque that is the product of these is set so that the OFF state is larger than the ON state as a result.
As a result, the torque acting on the locking lever 8 based on the return spring 17 becomes larger in the OFF state than in the ON state, as in the case of the second embodiment, and the occurrence of the miss lip during the ON operation is suppressed. Other operations and actions are the same as those in the first and second embodiments, and thus the description thereof will be omitted.

Embodiment 4 FIGS. 11 to 16 show Embodiment 4 of the present invention, FIG. 11 is a longitudinal sectional view of a circuit breaker in an ON state, and FIG. 12 is an exploded perspective view of essential parts in FIG. 13 is an enlarged view of the ON state of the operation mechanism portion in FIG. 11, FIG. 14 is an enlarged view of the trip display state, FIG. 15 is an enlarged view of the reset operation process, and FIG. 16 is an enlarged view of the OFF state.

First, in FIGS. 11 and 12, the structure of this circuit breaker is similar to that of the second embodiment of FIGS. 5 and 6, but is different in the following two points. The first difference is that the reset spring 14 is provided between the operation handle 2 and the link 4 in the opposite direction to the return spring 17 of the second embodiment. The reset spring 14 is composed of a torsion spring like the return spring 17 and also serves as a return spring of the locking lever 8, but the operation handle 2 is moved counterclockwise (O in FIG. 11).
It is always biased in the FF direction), and its action is opposite to that of the second embodiment and is the same as that of the first embodiment of FIG. As for the reset spring 14, the spiral winding portion is inserted into the leg 4a of the link 4,
One end 14a thereof is on the outer periphery of the boss portion 2b of the operation handle 2, and the other end 14b is the spring hook portion 8d of the locking lever 8.
(Fig. 12). The locking lever 8 receives a force from the reset spring 14 in the counterclockwise direction in FIG.
a is attracted to the roller 16.

The second difference is that the trip indicating spring 31 is provided in the fourth embodiment. The trip display spring 31 is a torsion spring as shown in FIG.
The spiral winding portion is inserted into the shaft 3 supporting the operation handle 2. One end of the trip display spring 31 is bent in a hook shape and locked in the hole 32 of the frame 30, and the other end is bent in a V shape at a point P so as to escape the leg 4a of the link 4 during a trip operation described later. Further, the tip is further bent into a mountain shape, and an inclined surface 31b is formed at the tip. Further, the trip display spring 31 comes into contact with the projection 33 provided on the frame 30 at the point P, and the amount of deformation is limited.

The structure of the fourth embodiment is substantially the same as that of the second embodiment except for the above two points. Now, the trip operation and the reset operation will be described below with reference to FIGS. 13 to 16. Now, when the overcurrent flows in the ON state of FIGS. 11 and 13, the overcurrent trip device 18 already described
When the locking lever 8 is rotated clockwise by the action of, the holder 6 is pulled up by the action of the blocking spring 11, and the corner portion 6d hits the stopper portion 30a of the frame 30 as described in the second embodiment. Stop. On the other hand, the arm 2a of the operating handle 2 and the link 4 are connected to the reset spring 1
Due to the action of 4, it tries to change from a dogleg shape to an inverted dogleg shape. As a result, the leg 4b of the link 4 moves leftward to come into contact with the guide surface 30b of the frame 30, and further tries to move upward along the guide surface 30b.

However, when the leg 4b reaches the position shown in FIG. 14, the leg 4b comes into contact with the tip inclined surface 31a of the trip indicating spring 31 which projects so as to interfere with this, and the arm 2a and the link 4 are slightly reversed. Stop at the position shown in the figure.
At this time, the handle 2c of the operation handle 2 is in the ON position and the OF position.
It is located in the middle of the F position and indicates that the circuit breaker is in a trip state. By the way, if the trip display spring 31 is not provided, the leg 4b is raised until it hits the stopper portion 30c of the frame 30, and the handle 2c is inverted to the OFF position.

To reset from the state shown in FIG. 14, the operating handle 2 is manually turned upside down to the OFF position. As a result, the leg 4b is forcibly pulled up along the guide surface 30b, and the trip display spring 31 that loses this elastically deforms with the point P as a fulcrum to pass the leg 4b, as shown in FIG. Leg 4b that pushed away trip display spring 31
Is the stopper portion 30 of the frame 30 as shown in FIG.
Stop at c. At that time, the operation handle 2 is O
It has reached the FF position. In addition, in the meantime, the arm 2a and the link 1 which have an inverted V shape due to the action of the reset spring 14 are provided.
4, the holder 6 is pulled counterclockwise with the corner 6d as a fulcrum, and the latch surface 6a is again engaged with the latch pin 15 to complete the reset.

As described above, according to the configuration of the fourth embodiment, the leg 4b connecting the holder 6 and the link 14 at the time of trip operation is blocked by the trip display spring 31 and stopped during the movement, and the operation handle 2 Will stop in the middle of the ON and OFF positions without reversing to the OFF position all at once,
It is possible to reliably know that a trip has occurred from the stop position of the handle 2c. Further, if a manual operation force in the OFF direction is applied to the operation handle 2 from that state, the trip display spring 31 loses the force and allows the leg 4b to pass therethrough for resetting.

FIG. 17 shows a different embodiment of the trip indicating spring. In this case, trip display spring 31
Is formed from a leaf spring in the illustrated shape, and is fixed by caulking the projection 30d of the frame 30 inserted into the hole 34 at the base of the L-shaped cross section, and the leg 4b of the link 4 is attached to the free end.
An inclined surface 31a that interferes with is bent and formed. Since the action is exactly the same as that of the torsion spring, the explanation of the operation is omitted.

[0040]

According to the present invention, since the movement of the operating handle can be enlarged and given to the movable contactor, a larger opening distance of the movable contact can be obtained with the same operating stroke than the conventional one, and the size can be reduced. A circuit breaker with a large breaking capacity can be constructed. Further, since the vibration of the operation handle does not directly affect the locking portion of the holder, there is no risk of mis-strip during the ON operation. In that case, the torque acting on the locking lever is O
By configuring the FF state to be larger than the ON state, the pressing force of the locking lever to the latch pin side is increased during the transition process from the OFF state to the ON state, and the ON state is achieved without increasing the trip load. It is possible to prevent miss-strip during operation. Also, by providing a trip display spring and stopping the movement of the connecting shaft between the holder and the link during the trip, the operation handle is stopped midway between the ON position and the OFF position so that the occurrence of trip can be seen at a glance. can do.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a circuit breaker in an ON state showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of the same in the OFF state.

FIG. 3 is a vertical cross-sectional view at the same moment when the trip operation is performed.

4 is an exploded perspective view of essential components of the circuit breaker of FIG. 1. FIG.

FIG. 5 is a longitudinal sectional view of a circuit breaker showing an embodiment 2 of the present invention in an ON state.

6 is an exploded perspective view of essential components of the circuit breaker of FIG.

FIG. 7 is an enlarged view of the operation mechanism section in FIG.
N state, (B) is OFF state.

FIG. 8 is a longitudinal sectional view of a circuit breaker in an ON state showing a third embodiment of the present invention.

9 is an exploded perspective view of essential components of the circuit breaker of FIG.

10A and 10B are enlarged views of the operation mechanism unit in FIG. 8, in which FIG. 10A is an ON state and FIG. 8B is an OFF state.

FIG. 11 shows an ON state of a circuit breaker showing a fourth embodiment of the present invention.
It is a longitudinal cross-sectional view of a state.

12 is an exploded perspective view of essential components of the circuit breaker of FIG. 11.

13 is an enlarged view of the ON state of the operation mechanism section in FIG. 11.

14 is an enlarged view of a trip display state of the operation mechanism unit in FIG.

15 is an enlarged view of a reset operation process of the operation mechanism unit in FIG.

16 is an enlarged view of the OFF state of the operation mechanism section in FIG.

FIG. 17 is a perspective view of relevant parts showing a different embodiment of the trip indicating spring shown in FIG. 12;

[Explanation of symbols]

 1 Main body case 2 Operation handle 4 Link 6 Holder 6a Latch surface 8 Locking lever 9 Moving contact 11 Breaking spring 15 Latch pin 16 Roller 18 Overcurrent trip device 31 Trip indication spring

Claims (3)

[Claims] 1. A latch pin fixed to a main body case, a latch surface engaging with the latch pin at one end, and a movable contactor held at the other end. The latch pin is pivoted around the latch pin to move the movable pin. A holder that opens and closes the contact, and a holder that is rotatably supported by the holder and normally receives a spring force to cover the latch pin and keep the engagement between the latch pin and the latch surface. A locking lever that is rotated against the spring force by the action of a tripping device to release the engagement, an operation handle rotatably supported with respect to the main body case, and one end of the operation handle The link connected to the holder at the other end between the latch surface and the movable contact, and the contact in a direction in which the movable contact separates from the fixed contact facing the movable contact. Circuit breaker, characterized in that a cutoff spring which biases the dust. 2. The circuit breaker according to claim 1, wherein the torque acting on the locking lever based on the spring force is larger in the OFF state than in the ON state. 3. The operation is stopped halfway by interfering with a connecting shaft of a holder and a link which is fixed to the main body case and moves at the time of trip, and at the time of resetting, the manual operation force acting on the operation handle is lost. 2. The circuit breaker according to claim 1, further comprising a trip indicating spring that is elastically deformed to pass through the connecting shaft.