GB451233A - Improvements in and relating to gas-blast electric switches - Google Patents

Abstract

451,233. Gas-blast switches. BRITISH THOMSON - HOUSTON CO., Ltd., Crown House, Aldwych, London. Feb. 1, 1935, No. 3324. Convention date, Feb. 1, 1934. [Class 38 (v)] In a gas - blast switch wherein the point of interruption is located within or in the vicinity of a nozzle b of insulating material through which compressed gas flows in a single direction during the interrupting operation, one of the contacts d is arranged to pass into the open through an extension of the nozzle during the separating movement, while the other contact a, which has a diameter greater than that of the narrowest part of the nozzle, remains in its original position or is only slightly movable therefrom. The contact a may be solid, as shown, or it may be hollow and serve as a passage for compressed air. The position of the contact a may be adjustable manually, or automatically in dependence on the value of the current to be interrupted. In the arrangement shown in Fig. 4, the contact a is in series with an electromagnet i and under short-circuit conditions is withdrawn by the amount s, which can be adjusted by means of screws m, from the narrowest part of the nozzle b in order to open the passage for a more powerful gas jet. The contacts a, d may be in parallel with main contacts, which are separated before the separation of the contacts a, d. The Specification as open to inspection under Sect. 91 describes also arrangements with metal nozzles in which fixed or adjustable throttle members are inserted in front of the constricted portion. This subject-matter does not appear in the Specification as accepted.