GB285372A - Improvements in electrical contact make and break devices - Google Patents

Abstract

285,372. Bosch Akt.-Ges., R. Feb. 14, 1927, [Convention date]. lnterrupters, mechanical; cases; contacts.- Contacts for make-and-break switches working in a vacuum or inert gas are constructed to avoid the welding together by the arc which frequently occurs with such contacts. One or both contacts, and preferably that which is burnt away by the arc, is made in the form of a thin sheet of metal and without any metallic support, so that this contact becomes completely burnt away and holes are formed, or its surface decreases. In Fig. 1 the contacts comprise recessed thin metal sheets a, b riveted to their supports, the edge of one contact in operation being gradually burnt away so the arc metal passes to the other contact. In Fig. 3 the contacts are formed by rolling out the ends of wires e, f and are brought into contact by spring means or the resiliency of the wires. The point of contact gradually moves owing to the burning away of one contact. In Fig. 4 (not shown) a pair of such contacts are shown in a glass vessel wherein one contact is adjustable by the elasticity of the glass. Instead of the wire f being bent back, it may extend in the same direction as the wire e. The contacts may be of tungsten, molybdenum, or other metal of high temperature of vaporization.