GB843121A - Improvements in or relating to the manufacture of electric lamps and like devices - Google Patents

Abstract

843,121. Making incandescent electric lamps. GENERAL ELECTRIC CO. Ltd. May 20,1958 [March 22, 1957], No. 9503/57. Class 39(2). In the manufacture of a foot tube assembly for electric lamps and similar devices, the foot tube is supported with its axis vertical, a positioning member is introduced thereinto from below and lead-in wires are fed downwards through holes in a guide member located above the foot tube into recesses in the positioning member. The positioning member is then withdrawn still bearing the lead-in wires so that these remain in the position in which they are to be sealed into the foot tube. An exhaust tube may also be fed through an additional hole in the guide member into a further recess in the positioning member. In a continuously rotating machine for carrying out the process, the foot tubes 12 are fed to jaws 10 spaced at intervals round the apparatus and each associated with a guide block 20 comprising two sections pivoted together which close above the top of the foot tube forming two feeding channels 23 of the lead-in wire and a central feeding channel for the exhaust tube and with a mandrel 14 carried by a support 15 sliding on a shaft 16 and moved upwards and downwards by a cam 17. Initially the top of the mandrel just projects above that of the foot tube. The mandrel 14 fits closely inside the foot tube 12 and has two diametrically opposite grooves on its surface to receive the lead-in wires and a central hole of slightly greater diameter than the exhaust tube with an adjusting rod 36 mounted therein. At successive positions during the rotation of the machine, a lead-in wire 34 which may embody the usual fuse, is fed through one of the holes 23 into one of the grooves in the mandrel 14, the exhaust tube is fed through the central hole in the block 20 into the central hole in the mandrel, the second lead-in wire is similarly fed into place, and the mandrel moves downwards within a tube 13 so that the relative positions of the parts in the foot tube are maintained. Heat is then applied to the lower part of the foot tube and a pinch formed sealing the lead-in wires and exhaust tube in the foot tube. Air is then blown through the exhaust tube to create a hole in the side of the pinch and the mandrel and tube 13 are further lowered to free the foot tube assembly and allow this to be removed from the apparatus. Specification 835,921 is referred to.