JPH09115407A - Circuit breaker for wiring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent influence by arc gas, improve strength and reduce the overall width of a circuit breaker by enclosing a fuiger spring with a protectuie space provided in the rear. SOLUTION: A circuit breaking mechanism comprises a terminal plate 2 with a fixed contact 3, and a finger 4 with a movable contact 5 contacting the contact 3 or separating therfrom. This finger 4 is formed with a bent side plate 7 extending to the opposite side to the contact 5, on both sides of a front plate 6 to which the movable contact 5 is attached, and is formed in a letter U shape in section. A spring hook part 8 is formed thereat, a finger spring 9 is engaged with the part 8 and installed in a space surrounded by the side plate 7. When the finger 4 detecting that an overcurrent flows in a circuit is moved by the before of the spring 9, the movable contact 5 is separated from the fixed contact 3 forcibly to break a circuit. Arc gas generated in this case does not a effect the spring 9 in the space surrounded by the side plate 7, and the strength of the finger 4 is improved, and also the overall width of the circuit breaker is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a finger portion of a wiring breaker.

[0002]

2. Description of the Related Art A conventional circuit breaker for wiring uses a plate-shaped finger 31 as shown in FIGS.
A movable contact 32 is provided at the tip of the movable contact 32, a spring hook 33 is provided slightly above the movable contact 32, and a finger spring 34 is attached.

[0003]

However, in such a conventional device, since the spring contact portion 33 of the finger spring 34 is provided on the same plane as the movable contact 32, the fixed contact 35 and the fixed contact 35 are provided when the short circuit is interrupted. There is a possibility that the finger spring 34 is exposed to the high-temperature arc gas heat generated during the period. In addition, since the finger 31 has a flat plate shape, the arc gas easily flows into the back surface of the finger 31 and may affect other mechanical portions. Further, since the finger 31 has a flat plate shape, it is necessary to widen the width in order to provide strength, and the entire width of the circuit breaker for wiring must also be widened.

[0004] The present invention solves the above-mentioned conventional problems,
The purpose of the present invention is to provide a circuit breaker for wiring, which can prevent the heat of the arc gas from affecting the finger springs and other mechanical parts, and can also increase the strength of the fingers to narrow the width.

[0005]

SUMMARY OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, is formed by bending side plates extending opposite to the contacts on both sides of a finger having a movable contact at its tip. A finger spring is mounted in the space surrounded by these side plates.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the best mode for carrying out the present invention will be described in detail by taking the two-pole type circuit breaker shown in FIGS. 1 and 2 as an example. In the figure, reference numeral 1 is a case, and as shown in FIG. 2, a two-pole blocking mechanism is incorporated on the left and right of the central insulating partition wall 1a. 2 is a terminal board with a fixed contact 3
Is a finger having a movable contact 5 at the tip end thereof, which comes in contact with and separates from the fixed contact 3.

Each finger 4 has side plates 7 and 7 extending on opposite sides of the front plate 6 to which the movable contact 5 is attached and opposite to the contacts.
Is bent to have a U-shaped cross section. Further, the upper portion of the front plate 6 is bent to the side opposite to the contact, and a spring hook portion 8 is formed in that portion. And finger spring 9
Is mounted in the space surrounded by the side plates 7, 7 with its lower end engaged with the spring hook portion 8. As shown in FIG. 2, each finger spring 9 is attached so as to be located on the center axis of the finger. Further, the finger spring 9 is provided with a spring hook 8 at a portion where the front plate 6 of the finger 4 is bent on the side opposite to the contact, and the bending angle is bent on a straight line between the contact and the spring hook 8 of the finger spring 9. The part 14 is set to be blocked.

Reference numeral 10 denotes a handle, and the upper ends of the fingers 4 and 4 are pivotally attached by a shaft pin 11. Reference numeral 12 is a mountain-shaped cradle that determines the stable position of the handle 10, and the upper end of the finger spring 9 is locked in a locking hole 13 provided in the central top portion thereof.

In the circuit breaker of the present invention thus constructed, the finger 4 is moved in the counterclockwise direction in FIG. Forcibly separating 5 from the fixed contact 3 to interrupt the circuit is the same as the conventional one. However, in the present invention, the finger springs 9 are mounted in the space surrounded by the side plates 7, 7 formed on both sides of the finger 4 on the opposite side of the contacts, and are located rearward of the mounting surface of the movable contact 5. positioned. Therefore, the arc gas generated when the movable contact 5 separates from the fixed contact 3 does not affect the finger spring 9. Further, since the side plates 7 and 7 are bent and formed on both sides of the rear portion of the finger 4, the arc gas is blocked and does not flow into the mechanical portion on the back surface of the finger 4.

The finger 4 has side plates 7 and 7 on both sides of the rear portion.
It has a U-shaped cross section and is stronger than the conventional flat plate. Therefore, the width of the finger 4 can be reduced, and the overall width of the wiring breaker can be reduced. Therefore, it is possible to construct a two-pole wiring breaker having the same width as the conventional single-pole wiring breaker.

[0011]

As is apparent from the above description, the present invention can prevent arc gas from affecting the finger spring, and can protect the mechanical portion arranged at the rear part of the finger from the arc gas. Moreover, the strength of the fingers can be increased and the overall width of the circuit breaker for wiring can be narrowed. Therefore, the present invention is extremely significant in that it contributes to the development of the industry as a circuit breaker for wiring that solves the conventional problems.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing the embodiment of the present invention.

FIG. 3 is a partially cutaway front view showing a conventional example.

FIG. 4 is a partially cutaway side view showing a conventional example.

[Explanation of symbols]

 1 Case 1a Insulating Partition 2 Terminal Plate 3 Fixed Contact 4 Finger 5 Moving Contact 6 Front Plate 7 Side Plate 8 Spring Cover 9 Finger Spring 10 Handle 11 Shaft Pin 12 Cradle 13 Locking Hole 14 Bent

Claims (1)

[Claims] 1. A finger having a movable contact (5) at its tip.
The side plates (7) and (7) extending on the opposite side of the contact are bent and formed on both sides of (4), and the finger spring (9) is placed in the space surrounded by these side plates (7) and (7). ) Is attached to the circuit breaker for wiring.