SE304788B - - Google Patents

Abstract

<PICT:1102075/C1/1> In a method of manufacturing an electrical device, e.g. an incandescent lamp, discharge lamp, glow switch or relay comprising an envelope 1 and current supply wires 7, 8 secured thereto, in which at least one current-supply wire is connected to an internal member 3, 5 of the device fixedly connected to the envelope 1, the glass envelope is locally softened at an area 11, 12 other than where the internal member is or is to be fixedly connected to the envelope, and is pushed inwards at the softened area 11, 12 to engage the internal member 3, 5 and determine the position of at least a part of this member in the envelope. As shown, in a switch two nickel supports 3, 4 are embedded at one end in a flat foot 2. Bimetallic strips 5, 6 are welded to the other ends. The supports 3, 4 are connected to copper clad current supply wires 7, 8 in the foot 2. This combination of parts is inserted into the lower end of a glass tube 1 and a flat pinch produced to form a seal at the foot 2. The glass tube is then softened at two diametrically opposed portions 11, 12 and two wedges 13, 14 pushed against these areas to form two re-entrant parts which engage against the supports 3, 4 holding them the desired distance apart. The tube 1 is then drawn out at its upper end, exhausted, filled with a gas and finally sealed.