CN221262264U - Miniature circuit breaker - Google Patents

Abstract

The utility model discloses a miniature circuit breaker, which comprises a cable, a circuit breaker shell, a movable contact point, a closing mechanism, a locking mechanism and an iron core, wherein the upper side and the lower side of the circuit breaker shell are provided with sliding cavities, connecting terminals are connected in a sliding mode in the sliding cavities, a push rod is connected in a sliding mode on the right side of the sliding cavities, a static contact point is inserted into each connecting terminal, the movable contact point is driven by the closing mechanism, the locking mechanism is used for fixing the connecting terminals, a wire is wound on the iron core, two ends of the wire are respectively electrically connected with the movable contact point and the static contact point below, the connecting terminals are connected with the static contact point through connecting springs, and each push rod comprises a rod body, a limiting plate and a cap.

Description

Miniature circuit breaker

Technical Field

The utility model relates to the technical field of electrical equipment, in particular to a miniature circuit breaker.

Background

The circuit breaker is a mechanical switching device which can be used for switching on, carrying and breaking current under normal circuit conditions and also can be used for switching on, carrying for a certain time and breaking current under specified abnormal circuit conditions. Is commonly used in industrial, commercial, high-rise and residential sites.

In the prior art, the wiring installation of the circuit breaker needs to use tools, a connection mode of a wiring terminal at a wire inlet and outlet position and a connection mode of a cable are connected in a threaded compression mode, the installation in a narrow space is difficult, and an electrified part of the circuit breaker is still exposed when an operation and maintenance person overhauls, so that the risk of electric shock still exists.

When the circuit breaker is in a closing state, the cable can still be taken out through loosening threads at the connecting terminal, the possibility of misoperation of personnel still exists, and the safety is required to be improved.

Disclosure of utility model

In order to solve the problems, the utility model provides a miniature circuit breaker, which is realized by the following technical scheme.

The miniature circuit breaker comprises a cable, a circuit breaker shell, a movable contact point, a closing mechanism, a locking mechanism and an iron core; the circuit breaker is characterized in that a sliding cavity is formed in the upper side and the lower side of the circuit breaker shell, a wire inlet is formed in the position, corresponding to the left side of the sliding cavity, of the circuit breaker shell, a wiring terminal is connected in a sliding mode, the upper side and the lower side of the wiring terminal are arranged in an opening mode, the right side of the sliding cavity is connected with a push rod in a sliding mode, a static contact point is inserted into the wiring terminal, the static contact point is fixedly connected with the circuit breaker shell, one end of the static contact point stretches into the circuit breaker shell, a cable is electrically connected with the static contact point in the wiring terminal, the movable contact point is driven by a closing mechanism, when the left end of the movable contact point is in contact with the static contact point above, the circuit breaker is in a closing state, when the left end of the movable contact point is separated from the static contact point above, the circuit breaker is in a separating state, the iron core is fixed in the middle of the circuit breaker shell through an F yoke, a spiral wire is wound on the iron core, one end of the wire is electrically connected with the movable contact point, one end of the wire is electrically connected with a metal sheet, and the metal sheet is electrically connected with the static contact point below through the conductor, and when the circuit breaker is in the closing state.

Preferably, an arc extinguishing device is fixedly connected to the breaker shell on the left side of the iron core, the arc extinguishing device is provided with an arc extinguishing electrode, and the arc extinguishing electrode is fixed with a static contact point above.

Preferably, a wiring spring is fixedly connected between the static contact point and the right side plate of the wiring terminal.

Preferably, when the left side plate of the wiring terminal is in contact with the static contact point, the wiring spring is in a natural state.

Preferably, the push rod comprises a rod body, a limiting plate fixedly connected to the left end of the rod body and a cap detachably connected to the right end of the rod body, the limiting plate is located in the sliding cavity, the rod body is in sliding connection with the circuit breaker shell, and an electricity checking hole is formed in the centers of the rod body and the limiting plate.

Preferably, the closing mechanism comprises a main shaft and an operating handle; the upper portion of main shaft is articulated with the circuit breaker shell, the right-hand member and the main shaft fixed connection of movable contact point, operating handle's center is connected with the right side rotation of circuit breaker shell, articulates between operating handle and the bottom of main shaft has the connecting piece.

Preferably, the locking mechanism comprises a pressing component and a clamping component, and the pressing component and the clamping component are respectively used for fixing the upper wiring terminal and the lower wiring terminal when the circuit breaker is in a closing state.

Preferably, the compression assembly comprises a screw, a belt pulley and a connecting rod; the screw rod is meshed with the inner wall of the circuit breaker shell, the screw rod is symmetrically arranged on the front side and the rear side of the wiring terminal above, a belt groove and a pressure plate are respectively arranged on one side, close to the wiring terminal, of the screw rod, the belt pulley is rotationally connected to the inner wall of the circuit breaker shell and is symmetrically arranged on the front side and the rear side, the belt pulley and the belt groove on the same side are linked through a transmission belt, one end of the connecting rod is rotationally connected with the main shaft, and the other end of the connecting rod is eccentrically hinged with the belt pulley.

Preferably, the clamping assembly comprises a first bracket, a second bracket, a sliding block and a flashboard; the utility model discloses a circuit breaker, including binding post, first support, second support, connecting rod and connecting rod, the first support and the second support are located the below respectively binding post's rear side and front side, first support and second support are located the below respectively, first support and circuit breaker shell fixed connection, the second support is the Z shape, riser and first support sliding connection above the second support, the rigid coupling has a pair of hold-down spring between riser and the front panel of circuit breaker shell, the bottom inner wall rigid coupling of first support and second support has the rubber holding strip, slider sliding connection is between the curb plate of first support and second support top, the right side rigid coupling of slider has the layer board, and the front side of slider is the inclined plane, and the position that corresponds the inclined plane on the second support is the swash plate, the flashboard is L shape, the corner and the circuit breaker shell of flashboard rotate to be connected, eccentric articulated on the operating handle has the connecting rod, the other end and flashboard articulated, the diaphragm head and the position correspondence of layer board.

Preferably, the automatic power supply further comprises a countershaft, the upper end of the countershaft is rotationally connected with the breaker shell, a sliding groove is formed in the countershaft, an opening is formed in the upper portion of the sliding groove, the connecting piece is in a shape of a loop, the connecting piece enters the sliding groove through the opening and is slidably connected in the sliding groove, a fixing column is fixedly connected to the countershaft at the position corresponding to the top of the sliding groove, a reset spring is fixedly connected to the fixing column, the other end of the reset spring is fixed to the connecting piece, and a positioning clamping groove corresponding to the countershaft is formed in the head of a vertical plate of the flashboard.

The utility model has the advantages that,

1. The connecting terminal is driven to move by the push rod, so that the cable is inserted, and then the connecting terminal is reset under the action of the connecting spring to fix the cable.

2. The push rod comprises a rod body, a limiting plate and a cap, the cap is detachably connected with the rod body, an electricity checking hole is formed in the centers of the rod body and the limiting plate, the cap is taken down, and the circuit is overhauled through the electricity checking hole, so that the safety is improved.

3. The operating handle drives the main shaft to move through the connecting piece, and the main shaft drives the dynamic and static contact points to move, so that the circuit breaker is switched between a closing state and a separating state, and the state switching is convenient.

4. When the switch-off state is achieved, the pressing mechanism and the clamping mechanism are respectively contacted with the upper wiring terminal and the lower wiring terminal to fix the upper wiring terminal and the lower wiring terminal, so that the wiring terminals can smoothly move, and the connection of cables is facilitated.

5. When the switching-on state, binding post locks, can't take out the cable of connecting, avoids personnel maloperation, improves the security of equipment.

Drawings

In order to more clearly illustrate the technical solutions of the present utility model, the drawings that are needed in the description of the specific embodiments will be briefly described below, it being obvious that the drawings in the following description are only some examples of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1: the utility model relates to an isometric view of a miniature circuit breaker in a closing state;

Fig. 2: the utility model relates to a front view of a miniature circuit breaker in a breaking state;

fig. 3: the cable is structurally and schematically arranged;

Fig. 4: the structure schematic diagram of the cable after being installed is provided;

fig. 5: an exploded view of the pushrod of the present utility model;

Fig. 6: a schematic perspective view of the screw rod;

fig. 7: an exploded view of the first bracket, the second bracket and the sliding block;

Fig. 8: the transmission schematic diagram of the clamping assembly is provided;

fig. 9: the closing and locking mechanism of the present utility model is a rear view.

The reference numerals are as follows:

A-cable, 1-breaker housing, 11-sliding chamber, 12-wire inlet, 13-wire connection terminal, 131-wire connection spring, 14-push rod, 141-rod body, 142-limit plate, 143-cap, 144-electricity checking hole, 15-stationary contact, 16-arc extinguishing device, 17-arc extinguishing electrode, 2-stationary contact, 31-main shaft, 32-operating handle, 33-connector, 411-screw, 412-pulley, 413-connecting rod, 414-Pi Daicao, 415-platen, 416-driving belt, 421-first bracket, 422-second bracket, 423-slider, 424-shutter, 425-pressing spring, 426-rubber clip strip, 427-support plate, 428-connecting rod, 5-iron core, 51-F yoke, 52-wire, 53-sheet metal, 54-conductor, 6-auxiliary shaft, 61-chute, 62-opening, 63-fixing column, 64-return spring.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

As shown in fig. 1-9, the present utility model has the following specific examples.

Example 1

The miniature circuit breaker comprises a cable A, a circuit breaker shell 1, a movable contact point 2, a closing mechanism, a locking mechanism and an iron core 5; the circuit breaker is characterized in that the upper side and the lower side of the circuit breaker shell 1 are provided with a sliding cavity 11, a wire inlet 12 is arranged at the position, corresponding to the left side of the sliding cavity 11, of the circuit breaker shell 1, a wiring terminal 13 is connected in a sliding mode, the upper side and the lower side of the wiring terminal 13 are arranged in an opening mode, the right side of the sliding cavity 11 is connected with a push rod 14 in a sliding mode, a static contact point 15 is inserted into the wiring terminal 13, the static contact point 15 is fixedly connected with the circuit breaker shell 1, one end of the static contact point 15 stretches into the circuit breaker shell 1, a cable A is electrically connected with the static contact point 15 in the wiring terminal 13, a movable contact point 2 is driven by a closing mechanism, when the left end of the movable contact point 2 is in contact with the static contact point 15 above, the circuit breaker is in a closing state, when the left end of the movable contact point 2 is separated from the static contact point 15 above, the circuit breaker is in a separating state, an iron core 5 is fixed in the middle of the circuit breaker shell 1 through an F yoke 51, a spiral wire 52 is wound on the iron core 5, one end of the wire 52 is electrically connected with the static contact point 2, the other end of the wire 52 is electrically connected with a metal sheet 53, when the metal sheet 53 is electrically connected with the static contact point 15 below the static contact point 15 through a conductor 54, and the circuit breaker is in a closing state.

Further, an arc extinguishing device 16 is fixedly connected to the breaker housing 1 on the left side of the iron core 5, the arc extinguishing device 16 is provided with an arc extinguishing electrode 17, and the arc extinguishing electrode 17 is fixed with a static contact point 15 above.

Further, a connection spring 131 is fixedly connected between the static contact 15 and the right side plate of the connection terminal 13, and when the left side plate of the connection terminal 13 contacts with the static contact 15, the connection spring 131 is in a natural state.

Further, the push rod 14 includes a rod body 141, a limiting plate 142 fixedly connected to the left end of the rod body 141, and a cap 143 detachably connected to the right end of the rod body 141, wherein the limiting plate 142 is located in the sliding cavity 11, the rod body 141 is slidably connected to the circuit breaker housing 1, and an electricity inspection hole 144 is formed in the centers of the rod body 141 and the limiting plate 142.

As shown in fig. 3, during the process of the cable a being connected, the connection terminal 13 is pushed to the left by the push rod 14, so that a gap is formed between the left side plate of the connection terminal 13 and the static contact point 15, the cable a is inserted into the gap through the wire inlet 12, then the push rod 14 is released, and under the action of the connection spring 131, the connection terminal 13 moves to the right, so that the cable a is compressed, and the connection and fixation of the cable a are realized.

As shown in fig. 5, when it is required to repair or verify whether the circuit breaker is charged, the cap 143 is removed, the probe experience hole 144 on the multimeter is inserted and contacted with the connection terminal 13, so that it is possible to verify whether the circuit breaker is powered off or to determine whether the electrical circuit is faulty, thereby improving safety.

As shown in fig. 1-2, the moving contact point 2 is driven to move by the switching-on mechanism, when the left end of the moving contact point 2 contacts with the upper static contact point 15, the circuit breaker is in a switching-on state, and when the left end of the moving contact point 2 is separated from the upper static contact point 15, the circuit breaker is in a switching-off state.

The cable a is electrically connected with the static contact 15 in the connecting terminal 13, when the circuit breaker is in a "closing" state, when the movable contact 2 is in contact with the upper static contact 15, the current is conducted through the upper cable a to the upper static contact 15, then conducted to the movable contact 2, then conducted to the bimetallic strip 53 and the conductor 54 through the lead 52, and finally flows out through the lower static contact 15 and the cable a.

When in a closing state, the locking mechanism is used for locking and fixing the upper wiring terminal 13 and the lower wiring terminal 13, an operator cannot push the wiring terminal 13 through the push rod 14, the operator cannot take out the cable A, the possibility of misoperation is avoided, and the safety is improved.

The arc extinguishing electrode 17 of the arc extinguishing device 16 is connected with the upper static contact point 15, so that the arc generated when the static contact point 15 and the movable contact point 2 are electrified is eliminated, and the safety is improved.

Example 2

The closing mechanism comprises a main shaft 31 and an operating handle 32; the upper portion of main shaft 31 is articulated with circuit breaker shell 1, and movable contact point 2's right-hand member and main shaft 31 fixed connection, the center of operating handle 32 and the right side of circuit breaker shell 1 rotate to be connected, and the connecting piece 33 articulates between operating handle 32 and the bottom of main shaft 31.

In this embodiment, as shown in fig. 1, when the switch is turned on, the operating handle 32 is pushed upwards, the operating handle 32 drives the main shaft 31 and the moving contact point 2 to move through the connecting piece 33, and the head of the moving contact point 2 contacts with the upper static contact point 15, so that the switch is turned on; on the contrary, when the opening and closing is interrupted, the operating handle 32 is pushed downwards, and the movable contact point 2 is separated from the upper static contact point 15.

Example 3

The locking mechanism comprises a pressing component and a clamping component, and when the circuit breaker is in a closing state, the pressing component and the clamping component respectively fix the upper wiring terminal 13 and the lower wiring terminal 13.

The compression assembly includes a screw 411, a pulley 412 and a link 413; screw 411 meshes with the inner wall of circuit breaker shell 1 to the both sides around the binding post 13 of symmetry setting top, and one side that screw 411 is close to binding post 13 is equipped with belt groove 414 and pressure disk 415 respectively, and belt pulley 412 rotates to be connected at the inner wall of circuit breaker shell 1 and the front and back symmetry setting, and belt pulley 412 and belt groove 414 of homonymy pass through drive belt 416 linkage, and the one end of connecting rod 413 rotates with main shaft 31 to be connected, and the other end and the belt pulley 412 eccentric hinge of connecting rod 413.

In this embodiment, when the switch is turned on, the main shaft 31 drives the belt pulley 412 to rotate through the connecting rod 413, under the action of the driving belt 416, the belt groove 414, the pressure plate 415 and the screw 411 synchronously rotate, and as the screw 411 is meshed with the inner wall of the breaker housing 1, the rotation direction of the thread groove on the screw 411 is set, so that the screw 411 moves in a direction close to the terminal 13 when rotating, and the pressure plate 415 compresses the terminal 13 above; on the contrary, when the breaking is powered off, the screw 411 rotates reversely, the pressing plate 415 is separated from the upper connecting terminal 13, and the connecting terminal 13 can move to complete the connection and the replacement of the cable A.

As a further implementation of the present embodiment, the clamping assembly includes a first bracket 421, a second bracket 422, a slider 423, and a shutter 424; the first bracket 421 and the second bracket 422 are respectively positioned at the rear side and the front side of the lower wiring terminal 13, the first bracket 421 is fixedly connected with the breaker shell 1, the second bracket 422 is Z-shaped, a vertical plate above the second bracket 422 is in sliding connection with the first bracket 421, a pair of compression springs 425 are fixedly connected between the vertical plate above the second bracket 422 and the front side plate of the breaker shell 1, rubber clamping strips 426 are fixedly connected to the inner walls at the bottoms of the first bracket 421 and the second bracket 422, a sliding block 423 is in sliding connection between the first bracket 421 and the side plate above the second bracket 422, a supporting plate 427 is fixedly connected to the right side of the sliding block 423, the front side of the sliding block 423 is an inclined plane, the position corresponding to the inclined plane on the second bracket 422 is an inclined plate, the flashboard 424 is L-shaped, the corner of the flashboard 424 is rotationally connected with the breaker shell 1, a connecting rod 428 is eccentrically hinged on the operating handle 32, the other end of the connecting rod 428 is hinged with the flashboard 424, and the head of the transverse plate of the flashboard 424 corresponds to the position of the supporting plate 427.

When the switch-on is electrified, the operating handle 32 pulls the gate plate 424 through the connecting rod 428, so that the left end of the transverse plate of the gate plate 424 moves upwards, as shown in fig. 7 and 8, at the moment, the second support 422 moves backwards under the action of the compression spring 425, and pushes the sliding block 423 to move upwards, and under the action of the compression spring 425, the rubber clamping strip 426 at the front side clamps the wiring terminal 13 below; on the contrary, when the breaking and power-off are performed, the sliding block 423 moves downwards and pushes the second support 422 forwards, so that the lower connecting terminal 13 is released from being fixed.

As a further implementation manner of this embodiment, the auxiliary shaft 6 is further included, the upper end of the auxiliary shaft 6 is rotationally connected with the breaker housing 1, the auxiliary shaft 6 is provided with a sliding groove 61, an opening 62 is formed in the upper portion of the sliding groove 61, the connecting piece 33 is in a shape of a loop, the connecting piece 33 enters the sliding groove 61 through the opening 62 and is slidingly connected in the sliding groove 61, a fixing column 63 is fixedly connected to a position, corresponding to the top of the sliding groove 61, on the auxiliary shaft 6, a reset spring 64 is fixedly connected to the fixing column 63, the other end of the reset spring 64 is fixedly connected with the connecting piece 33, and a positioning clamping groove corresponding to the auxiliary shaft 6 is formed in the vertical plate head of the flashboard 424.

When the switch-on is electrified, the connecting piece 33 moves in the sliding groove 61 so as to drive the auxiliary shaft 6 to rotate, the reset spring 64 contracts and stores energy, and after the switch-on is finished, the head of the auxiliary shaft 6 enters into the positioning clamping groove to clamp the flashboard 424, so that the movement of the flashboard 424 is avoided, and the switch-on state is kept; on the contrary, when the breaking brake is cut off, the auxiliary shaft 6 rotates to be separated from the flashboard 424, and the flashboard 424 can move smoothly.

The preferred embodiments of the utility model disclosed above are intended only to assist in the explanation of the utility model. The preferred embodiments are not intended to be exhaustive or to limit the utility model to the precise form disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the utility model and the practical application, to thereby enable others skilled in the art to best understand and utilize the utility model. The utility model is limited only by the claims and the full scope and equivalents thereof.

Claims (10)

1. The miniature circuit breaker comprises a cable and is characterized by further comprising a circuit breaker shell, a movable contact point, a closing mechanism, a locking mechanism and an iron core; the circuit breaker is characterized in that a sliding cavity is formed in the upper side and the lower side of the circuit breaker shell, a wire inlet is formed in the position, corresponding to the left side of the sliding cavity, of the circuit breaker shell, a wiring terminal is connected in a sliding mode, the upper side and the lower side of the wiring terminal are arranged in an opening mode, the right side of the sliding cavity is connected with a push rod in a sliding mode, a static contact point is inserted into the wiring terminal, the static contact point is fixedly connected with the circuit breaker shell, one end of the static contact point stretches into the circuit breaker shell, a cable is electrically connected with the static contact point in the wiring terminal, the movable contact point is driven by a closing mechanism, when the left end of the movable contact point is in contact with the static contact point above, the circuit breaker is in a closing state, when the left end of the movable contact point is separated from the static contact point above, the circuit breaker is in a separating state, the iron core is fixed in the middle of the circuit breaker shell through an F yoke, a spiral wire is wound on the iron core, one end of the wire is electrically connected with the movable contact point, one end of the wire is electrically connected with a metal sheet, and the metal sheet is electrically connected with the static contact point below through the conductor, and when the circuit breaker is in the closing state.

2. The miniature circuit breaker of claim 1, wherein an arc extinguishing device is fixedly connected to the circuit breaker housing on the left side of the iron core, the arc extinguishing device is provided with an arc extinguishing electrode, and the arc extinguishing electrode is fixed with a static contact point above.

3. The miniature circuit breaker of claim 1, wherein a wire spring is fixedly connected between the stationary contact and the right side plate of the wire connection terminal.

4. A miniature circuit breaker according to claim 3 wherein said wire spring is in a natural state when the left side plate of said wire terminal contacts the stationary contact.

5. The miniature circuit breaker of claim 1, wherein the push rod comprises a rod body, a limiting plate fixedly connected to the left end of the rod body, and a cap detachably connected to the right end of the rod body, the limiting plate is located in the sliding cavity, the rod body is slidably connected with the circuit breaker shell, and the center of the rod body and the center of the limiting plate are provided with the electricity checking hole.

6. The miniature circuit breaker of claim 1, wherein said closing mechanism comprises a main shaft and an operating handle; the upper portion of main shaft is articulated with the circuit breaker shell, the right-hand member and the main shaft fixed connection of movable contact point, operating handle's center is connected with the right side rotation of circuit breaker shell, articulates between operating handle and the bottom of main shaft has the connecting piece.

7. The miniature circuit breaker of claim 6, wherein the latching mechanism comprises a hold-down assembly and a clamping assembly, the hold-down assembly and the clamping assembly respectively securing the upper and lower terminals when the circuit breaker is in the "on" state.

8. The miniature circuit breaker of claim 7, wherein said hold down assembly comprises a screw, a pulley and a linkage; the screw rod is meshed with the inner wall of the circuit breaker shell, the screw rod is symmetrically arranged on the front side and the rear side of the wiring terminal above, a belt groove and a pressure plate are respectively arranged on one side, close to the wiring terminal, of the screw rod, the belt pulley is rotationally connected to the inner wall of the circuit breaker shell and is symmetrically arranged on the front side and the rear side, the belt pulley and the belt groove on the same side are linked through a transmission belt, one end of the connecting rod is rotationally connected with the main shaft, and the other end of the connecting rod is eccentrically hinged with the belt pulley.

9. The miniature circuit breaker of claim 7, wherein said clamping assembly comprises a first bracket, a second bracket, a slider, and a shutter; the utility model discloses a circuit breaker, including binding post, first support, second support, connecting rod and connecting rod, the first support and the second support are located the below respectively binding post's rear side and front side, first support and second support are located the below respectively, first support and circuit breaker shell fixed connection, the second support is the Z shape, riser and first support sliding connection above the second support, the rigid coupling has a pair of hold-down spring between riser and the front panel of circuit breaker shell, the bottom inner wall rigid coupling of first support and second support has the rubber holding strip, slider sliding connection is between the curb plate of first support and second support top, the right side rigid coupling of slider has the layer board, and the front side of slider is the inclined plane, and the position that corresponds the inclined plane on the second support is the swash plate, the flashboard is L shape, the corner and the circuit breaker shell of flashboard rotate to be connected, eccentric articulated on the operating handle has the connecting rod, the other end and flashboard articulated, the diaphragm head and the position correspondence of layer board.

10. The miniature circuit breaker according to claim 9, further comprising a secondary shaft, wherein the upper end of the secondary shaft is rotatably connected with the circuit breaker housing, a chute is formed in the secondary shaft, an opening is formed in the upper portion of the chute, the connecting piece is in a shape of a loop, the connecting piece enters the chute through the opening and is slidably connected in the chute, a fixing column is fixedly connected to the secondary shaft at a position corresponding to the top of the chute, a return spring is fixedly connected to the fixing column, the other end of the return spring is fixed to the connecting piece, and a positioning clamping groove corresponding to the secondary shaft is formed in the head of a vertical plate of the flashboard.