GB818772A - Improvements in and relating to electric circuit interrupters - Google Patents

Abstract

818,772. Fluid-blast switches. ENGLISH ELECTRIC CO. Ltd. Jan. 6, 1956 [Jan. 14, 1955], No. 1193/55. Class 38 (5). In a fluid-blast switch having at least one movable contact arranged on a rotatable operating shaft, a spring-biased pump has a unidirectional operative connection with the shaft and is arranged so that when the shaft is turned to close the contacts, the pump is driven to charge it with fluid and to stress the biasing spring or springs and when the shaft is turned to open the contacts, the pump under the action of the spring or springs tends to cause a flow of arc-quenching fluid in the region of the contact gap. In the Figure, the driving sleeve 33 of the pump is free to rotate on the operating shaft 17 to which it is connected by a ratchet (not shown). Rotation of the shaft 17 in the anti-clockwise closing direction causes vanes 35 carried by the sleeve 33 to traverse arcuate chambers 36 to charge them with fluid which enters through a suction valve (not shown). At the same time springs 37 are stressed. During an opening operation, the ratchet permits the shaft to move rapidly to the open position without retardation due to the pump. The springs 37 then cause the clockwise rotation of the sleeve 33 and vanes 35 to discharge the fluid from the pump through exit ports 38. into the contact chambers of the switch when the are-generated pressure in the contact chambers is sufficiently low to permit the opening of a non-return valve associated with them. In a modified arrangement, Fig. 4 (not shown), the pump has only one chamber and is biased by a clockspring. The general arrangement of the switch may be that described in Specification 816,321 and it may be detachably mounted in a housing as, described in Specification 817,093.