Patent GB-247923-A (GB)
Title: Improvements in and relating to machines for making electric incandescent lamps and similar articles
IPC: H01J5/62
Filed: 1925-12-23
Abstract: 247,923. British Thomson-Houston Co., Ltd., (Assignees of Malloy, J. J., Rippl, F. J., and Fagan, J. T.). Feb. 21, 1925, [Convention date]. Caps; filaments. - Comprises a machine for fixing contact bases or caps to bulbs, trimming the leading- in wires and soldering them to the contacts, and flash-aging the finished bulbs. The bulbs and the caps containing cement are assembled in holders on a rotating turret, upon which they are carried through several heating stages to set the cement before the wires are trimmed. At the trimming position a finger raises the wire 26 that is to be soldered to the shell 24<1> of the cap, to the position shown in broken lines in Fig. 5; grippers 51, 52, Fig. 4, then hold the wire close to the cap while a cutter 54<1> slides over the grippers 51 and trims off the wire. The grippers and the cutter are operated by common reciprocating pins 55, 56 working in cam-slots 56<1>, 57<1>. Simultaneously the central wire 25 is seized by grippers and trimmed by a cutter 59. The projecting end of the wire 26 is then pressed close to the cap. At the next position of the bulb flux is applied to the parts to be soldered by means of points 92, 93, Fig. 8. The flux is contained in a pot 90. Fig. 9, and is carried up to the retracted points 92, 93 by cups 94, 95 mounted on a vertically reciprocating rod 97. The points are mounted on rods resiliently slidable in tubes 104, 105, the tube 104 being rigidly mounted on a slide 108, and the tube 105 being carried by an arm 111 pivoted both at 115 to the slide 108 and at 114 to a rod 116 slidable on that slide. When the rod 116 is projected by a lever 117 it moves the slide 108 with it until this is arrested by a stop 126, when the flux-applying point 92 is in contact with the cap 24<1>, and then the rod 116 continues against the action of a spring 127, causing the arm 111 to swing down to apply flux to the centre contact of the bulb. At the next two positions of the bulb, solder is applied successively to the top and side contacts. The molten solder for the top contact is contained in a pot 128, Fig. 12, provided with deep apertures 131 to receive gas flames or electric heating cartridges. A slide 133 reciprocated in the bottom of the pot is provided with a hole 134 which is brought into register alternately with an aperture 135 in the bottom of the pot and with a nozzle 132, thereby conveying measured quantities of solder from the pot to the nozzle, from which it is pushed by a vertical ram 137 to fall on to the cap of the bulb. The pot for the supply of solder to the side contact is arranged similarly, the slide being vertical and the ram horizontal. The slides and rams are driven resiliently in both directions. In several succeeding positions the bulb is allowed to cool, and in the first five of these positions the filaments are flashed by the application to the bulb contacts of contacts 228, 229, Fig. 21, mounted on a vertically rocking plate 208, the contacts 228 being rigidly and the contacts 229 resiliently mounted. The bulbholders are resiliently mounted so that the pressure of the flashing-contacts depresses the bulbs with respect to their upper supports 30, to the position shown in Fig. 21, to avoid short-circuits between the contacts. The cam that operates the flashing-contacts is arranged to close the circuit switch only when the bulb has been depressed to a safe position. At the last cooling position the bulb is again flashed for inspection purposes. Vacuum bulbs are flashed in the first three positions at 110 per cent of their normal voltage, and in the last three at 130 per cent. Gas-filled bulbs are flashed at normal voltage. An electric circuit diagram of the machine is given, wherein a switch allows the different conditions for vacuum and gas-filled bulbs to be obtained, and showing ballast resistances used in series with vacuum bulbs and overload circuitbreaking devices arranged to indicate the presence of bulbs with short-circuited filaments at the flashing positions.