GB407354A - Improvements in or relating to electric circuit interrupters - Google Patents

Abstract

407,354. Arc-rupturing in switches. WESTINGHOUSE ELECTRIC & MANUFACTURING CO., East Pittsburg, U.S.A.- (Assignees of Slepian, J.; 1115, Lancaster Street, Pittsburg, U.S.A.) Sept. 15, 1932, No. 25670. Convention date, Oct. 13, 1931. [Class 38 (v).] In order to extinguish an arc, solid material is provided which, when acted upon by the arc, generates a non- inflammable, preferably condensable gas which passes through the arc in the form of a blast. A tubular casing 5 of fibre (Fig. 4) contains a series of discs 15 of the solid material, through an aperture 17 in the centre of which discs passes the movable contact 43 into engagement with fixed contacts 41 under spring action 45. When the contact 43 is lowered to open circuit, the arc formed acts on the material comprising the discs 15, thereby generating gas which passes up through the space between the contacts 41 into a number of small condenser tubes 39, the gas deionizing the arc in its passage therethrough. Suitable materials are ammonium alum, gypsum, and boric acid, the latter being preferred because of its good insulating properties even at high temperature, and of its non-hygroscopic nature. Fusible cut-outs. Fig. 1 shows a fusible strip 19 within the aperture 17 in the discs, the strip being connected to a collar 27 under spring action 29. Connection with the terminal 9 is made by means of a disc 33 and conductor 35 which slides on the collar 27.