SU1282232A1 - Contact system - Google Patents

Abstract

The invention relates to the field of electrical equipment, to low-voltage electric devices of control circuits and can be used in electric devices containing bridge-type contacts with contact pads of expensive contact material. The purpose of the invention is to save contact material. The contact device contains a contact bridge 2 with contact pads 3 of the smallest and 4 most mass, stationary contacts 5 and 6 with contact plates 7 of the smaller and 8 more mass. When the crosshead 1 acts on the contact bridge 2 with the force F, the latter rotates clockwise around point A and under the Influence of the moment begins to separate the contact pads 4 and 8, igniting an electric arc between them, which goes out before the distance between them reaches the value E, chosen from the condition that the maximum duration of burning of the arc of disabling when switching control circuits does not exceed the duration of one half-period of alternating current. The contact pads 3 and 7 are dispersed after reaching the distance t between the contact pads 4 and 8, therefore, they make the second break of the already de-energized circuit and operate in non-erosion mode. 2 Il. h (L

Description

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The invention relates to electrical equipment, namely to low-voltage electrical apparatus of control circuits, and can be used in electrical apparatus containing contacts of bridge bridges with contact pads of expensive contact material.

The purpose of the invention is to save contact material.

FIG. 1 shows the contact device in the on position; in fig. 2 - the same, in the disabled position.

The contact device contains a movable yoke 1, performing reciprocating movement under the action of an external force F or a return spring spring force RP, a contact bridge 2 with contact plates 3 and 4, respectively, of smaller and larger mass, fixed contacts 5 and 6 with contact plates less than 7 and more than 8 mass, the gap f between the contact pads 4 and 8, fixed at the moment of contact of the contact pads 3 and 7.

Contact system works as follows.

When the crosshead I acts on the contact bridge 2 with a force P ″ (Fig. 2), the latter rotates clockwise around point A under the influence of the moment fiib begins to dissolve the contact pads 4 and 8 at a speed V, igniting an arc between them earlier

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than the distance between them will reach a value selected from the condition that the maximum duration of the arcing of an electric arc when switching control circuits does not exceed the duration of one half-period of alternating current.

The discrepancy between the contact pads 3 and 7 occurs after reaching the distance E between the contact pads 4 and 8, therefore, they make the second break of the already de-energized circuit and work in the non-erosion mode.

Claims (1)

Invention Formula A contact system with two consecutive breaks in the chain, containing a movable yoke, contact bridge, two fixed contacts and contact plates fixed to the fixed contacts and contacts of the contact bridge, characterized in that, in order to save contact material, contact plates installed on the side of one of the chain breaks, exceed the mass of the contact material lining installed on the side of the second break, and the contact system is organized so that in the position of the movable contact bridge are corresponding to touching point of contact pads lesser mass between the contact plates there is a gap of greater mass.