GB1101905A - Method and equipment for the manufacture of starters for gas discharge tubes - Google Patents

Abstract

<PICT:1101905/C1/1> <PICT:1101905/C1/2> In a process for manufacturing starter switches, Fig. 1, for gas discharge tubes, the lead-in wires 1, which are sealed in a glass bead 2 and attached to the switch electrodes 3, 6, are inserted into one end of a glass tube 9, Fig. 2 (III), the end of the tube is melted by burners 10 and pinched to seal the lead-in wires in place, and the tube is heated at a position beyond the switch electrodes to soften the glass which is then drawn out to form an integral exhaust tube 13, Fig. 2 (VI), for evacuating the bulb of the switch. The process is performed in an apparatus which includes a clamp 8 for the other end of the glass tube and a head 7 which grips the lead-in wires, the clamp being moved away from the head during the drawing operation. In a preferred head (Fig. 3, not shown), the wires (1) are received in boreholes (23) and are clamped by a spring-loaded pressure plate (16), an adjustable stop (15) being provided to abut the ends of the wires and determine the distance between the bead (2) and the pinch seal.