Contact locking device of single-breakpoint molded-case low-voltage circuit breaker

Abstract

The invention discloses a contact locking device of a single-breakpoint molded-case low-voltage circuit breaker, which comprises a movable moving contact and a rotating shaft, wherein the rotating shaft is provided with a cavity; the rotating end of the moving contact is arranged in the cavity; a mandrel runs through a hole on the moving contact; the two ends of the mandrel are connected with therotating shaft; a shaft is transversely positioned in front of the outer outline surfaces of two sidewalls of the rotating shaft; a groove at the top rotating end of the moving contact is clamped on the shaft; another shaft is arranged at the top ends of the two sidewalls of the rotating shaft, and is connected with the upper ends of tension springs of which lower ends are connected with the first shaft; and each of the outer outline surfaces has a highest point at a longest distance away from the mandrel, and when the moving contact is repulsed by a longest distance, the first shaft passes by the highest point. As the moving contact is reliably locked under the action of the tension springs after passing by the position of the highest point which is a dead point, the contact locking device of the single-breakpoint molded-case low-voltage circuit breaker has the characteristics of simple structure, convenient operation and reliable movement, and can effectively prevent the moving contact from falling off and avoid an arc of the moving contact being re-ignited.

Description

technical field [0001] The invention relates to a molded case low-voltage circuit breaker for limiting current on-off, in particular to a contact locking device for the low-voltage circuit breaker. Background technique [0002] During the working process of the molded case low-voltage circuit breaker, when there is a large fault short-circuit current in the line, before the operating mechanism operates, the moving contact overcomes the contact pressure under the action of the electric repulsion and repels in advance, while the rotating shaft is still. . The function of the contact locking device is: after the dynamic and static contacts are separated to the maximum opening distance, the moving contact stays at the maximum position until the operating mechanism is released under the action of the release, so as to avoid the moving contact due to The fault short-circuit current decreases and the drop causes the arc to reignite. The existing contact locking device is as follo...

AI Technical Summary

Problems solved by technology

The existing contact locking devices are as follows: one is to adopt a connecting rod structure, and when the connecting rod moves past the dead point, it will control the moving contact so that it does not fall, but its disadvantages are: the structure is complicated and the assembly is inconvenient; The shape of the contact, when the moving contact turns over a certain angle, the special shape set on the shape of the moving contact will block the moving contact so that it does not fall, but its defect is: the special shape on the moving contact is easy to wear , cannot be reliably locked

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