Patent GB-695226-A (GB)
Title: Improvements in methods of and apparatus for assembling filament mounts for electriclamps
IPC: H01K3/06
Filed: 1951-01-26
Abstract: 695,226. Making electric incandescent lamps. BRITISH THOMSON-HOUSTON CO.. Ltd. Jan. 26, 1951 [Jan. 31, 1950], No. 2069/51. Class 39(ii) In order to assemble a filament mount accurately relative tc the reflector section of an electric incandescent lamp of the type comprising a reflector section and lens or cover section sealed thereto the lead-in wires or leads are pre-arranged in a group with their inner ends in predetermined spaced relationship to support a filament, and their outer ends positioned in approximately the same arrangement as the thimble-like terminals of the reflector section and, while e maintaining their relative spacing, are transferred to the reflector section and positioned therein with the inner ends of the leads in a definite predetermined position relative to the reflecting surface, and their outer ends within, but out of contact with the terminals, in readiness for attaching thereto without disturbing their relative positions. In an example comprising the manufacture of a double filament lamp, the leading-in wires 1-4 are bent to the requisite shape in a device 5, Fig. 1, and then removed therefrom in a jig 7, Fig. 2, and transferred manually into a lamp reflector section 6, Fig: 6. The leads 1-4, consisting of wire of substantial gauge, are first inserted end foremost into four spaced openings 19a ... 19d in the horizontal upper surface of a stationary die block 20, Fig. 3, which is positioned on a bed plate 27, Fig. 1. As shown, the openings 19a, 19b which receive two of the leads are close together, and the openings 19c and 19d are disposed relative thereto to form the corners of a triangle. Bending of the parts of the wires which extend above the die plate, and provide the inner ends of filament supports, is effected by dies 21-23 mounted eccentrically on the ends of journals 25 which are rotatable within bearing blocks 26 secured on the bed-plate 27, rotation of the respective journals and dies thereon being effected by the manual operation of radial handles 28. The die 21 is arranged to engage and bend the two closely adjacent wires 1, 2. In operation the dies first bend the wires across the top surface of the stationary dieblock 20 and into engagement with an upstanding centre portion 24 of the block, and then force the intermediate free portions into the angle between the adjacent faces of the block 20 and portion 24. As shown, the face of the die 21 that bends the two wires 1, 2 is provided with two relatively offset faces 29, 30 which engage the respective leads, and the parts of the centre portion 24 which engage the faces 29,30 cause the wires 1, 2 to be bent in slightly different directions at different points along their lengths; at the same time the leads 3 and 4 are bent into vertical grooves 37, 38 in the faces 39, 40 of the centre portion 24. After having bent the wires the dies 21-23 are rotated back to their original positions preparatory to the application of the jig 7 to the bending device. The jig 7, Fig. 2, is provided with a pair of manipulating handles 41, 42, the former being fixed and the latter pivoted at 50 on a rigid, portion 1 of the jig, there being a compression spring 52 located between the upper ends, of the handles. The spring 52 urges the lower end of handle 41 inwardly against a pair of clamping-pins 48, 49, Fig. 4, slidably mounted in guideways and each associated with a spring 53 urging it outwardly of the guideway. Normally the spring 52 between the handles maintains the ends of the clamping-pins in an inward blocking position across the inner ends of openings 47a-47d in the lower face 46 of the jig, until a squeezing pressure is exerted on the handles to compress the spring 52. With the handles 41, 42 pressed together the jig is positioned upon the bending device 5, the accuracy of positioning being facilitated by locating-pins 13, 14 which project upwardly from the device 5 and engage respectively within a hole 43, Fig. 4, and a groove 44 in the jig. Upon releasing the grip on the handles 41, 42 the conical ends of the clamping pins grip the parts of the leading-in wires 1-4 within the jig. Thus gripped in the jig 7 the wires 1-4 are lifted from the bending device 5 and transferred to the lead-attaching device 8, Fig. 6, within which a reflector 10 provided with terminal thimbles 11 is already positioned, the accurate insertion of the jig into the device being facilitated by causing the openings 43, 44 in the jig to register with locating- posts 15, 16 on the device 8. Before the jig is introduced a centring ring 56 is lifted from the position shown in Fig. 6 to enable the reflector section 6 to be inserted into the lead-attaching device, the correct position of the reflector being pre-determined by providing its rim with three non- uniformly spaced bosses 57 which engage within corresponding notches 58 in pads on a locating ring 62. The centring ring 56 is next lowered until three equidistantly spaced rollers 65 supported from its underside are brought to bear upon the reflector surface, this pressure being maintained while the jig is within the device 8. When the jig is lowered the wires 1-4 extend downwardly therefrom through openings 76 in the reflector into the thimbles 11. In the example the closely adjacent wires 1 and 2 enter a single thimble. The wires are arranged to enter a thimble without touching adjacent parts of either' the reflector or thimble and are attached to the thimbles by melting pellets of solder by means of gas burners 78 so that the solder flows around the wires without disturbing their position. The jig is subsequently removed and the reflector section transferred to a filament mounting machine of the type described in Specification 546,803. The apparatus shown in Fig. 6 may be. used in conjunction with a focusfinding device of known type. Specifications 515,091 and 557,598 also are referred to. In a modification Figs. 8, 11 (not shown), a filament is mounted upon the ends of a pair of leading-in wires prior to the sealing of the latter within the thimble terminals of a reflector section, the leading- in wires being first bent to the required shape, preferably in a device of the form shown in Fig. 1, and then transferred in a jig to the filament-mounting device. The jig is again used to transfer the mounted filament to the apparatus shown in Fig. 6.