GB724640A - Improvements relating to the manufacture of electric incandescent lamps - Google Patents

Abstract

724,640. Capping electric lamps. BRITISH THOMSON-HOUSTON CO., Ltd. Sept. 18; 1953 [Sept. 19, 1952], No. 25855/53. Class 39 (2). In the manufacture of electric incandescent lamps comprising a vitreous envelope and a metal base or cap attached thereto, the base having an indentation in the side-thereof leading to an aperture through which one of the leading-in wires extends, the leading-in wire is broken off by bending it sharply at a point immediately beyond that at which it emerges from the indentation and the end of the wire is soldered to the metal of the base within the indentation, so that substantially no part of the solder projects beyond the wall of the base. In the example a lamp of the miniature type adapted to be pushed bulb-foremost into a sleeve-like socket has a thin-walled cylindrical metal cap 3 of larger diameter than the bulb 2 provided with an indentation of substantially inverted V outline, with the apex of the V nearer to the end closure 21 of the cap. An aperture 26 in the deepest portion of the indentation for the passage therethrough of the leading-in wire 11 may be produced when forming the indentation by means of a punch and die and, by tensioning the wire upwardly and then pulling it down upon the edge of the metal a reverse bent 11a is produced at which the wire is severed. The cap is heated by playing a tiny hydrogen reducing flame into the depression to ensure that a solder wire will melt when applied to the indented metal and effect a joint by a mass of solder 33 upon that part and the leading-in wire.. The tensioning and shearing operations may be effected automatically in a machine of the type described in Specification 247,923, [Class 39 (ii)], by providing a pair of pivotable spring-loaded jaws 31 at one of the work stations of the machine.