Patent GB-716698-A (GB)
Title: Improvements in and relating to methods of and apparatus for making miniature electric incandescent lamp mounts
IPC: H01K3/10
Filed: 1952-10-23
Abstract: 716,698. Making mounts for electric lamps. BRITISH THOMSON-HOUSTON CO., Ltd. Oct. 23, 1952 [Oct. 31, 1951], No. 26622/52. Class 39 (2) In making miniature lamp mounts comprising spaced leading-in wires extending from a bead of insulating material, a filament connected to the ends of the leading-in wires, and an intermediate filament-supporting wire also retained by the bead, the intermediate supporting wire 8, Fig. 2, is first bent to a preliminary oblique position relative to the leading-in wires 5, 6, with its end portion 11, Fig. 3, extending back towards the plane of those wires, a filament 35 is mounted across the ends of the leading-in wires, and the main portion of the intermediate supporting wire 8 is bent back to align it with the leading-in wires and position the end portion between the filament and the bead 7, the said end portion of the supporting wire being subsequently bent away from the bead, the end hook 10 closed around the central part of the filament, and the wire 8 re-bent to provide a positive support for the filament 35, Fig. 7. The mounts are carried in a series of work holders 1 around the periphery of an indexing turret, and halted at a station A where forming-devices 3, Fig. 8, comprising a horizontally sliding blade 12 in co-operation with a swinging finger 15 bend the supporting- wire 8 to the form shown in Fig. 3. The blade 12 is mounted on a slide 13 which is operated through a bell-crank 22 linked to a vertical push rod 20, while the finger 15 is carried by an arm 17 controlled by a pivoted arm 26 which is biased downwardly by a tensioned spring 31 and operated by a vertically reciprocating push rod 21 in abutment with an adjustable screw 29 in the arm 26. The mount is next indexed to station B, Fig. 1 (not shown) where a coiled filament is attached to the hooks 9 at the inner ends of the leading-in wires 5, 6 by automatically operated apparatus. At the next work station C the leading-in wires are operated upon by pivoted fingers 38, 39, Figs. 10 and 11, which are swung inwardly against their lower ends and bend them almost vertically to allow a central finger 37 to raise the centre of the filament to a position slightly above the hook 10 at the end of the supporting- wire 8. The bending-fingers 38, 39 are mounted on pivots 51 on the bifurcated upper end of an upstanding arm 40 which is pivoted within a central opening in a vertical supporting standard 41, Fig. 10, and rocked forwardly therein into the operative position under pressure from an abutment screw 57 in an operating lever 42, the lower end of the latter being straddled about the upstanding arm 40 and carried by the same pivot 43. A tensioned spring 44 tends to hold the operating lever 42 rearwardly. Operation of the lever 42 is effected by a vertically movable bar 46 which is connected to the lever by a tensioned spring 48, so that initially the lever is pivoted clockwise by upward movement of the bar, and a pin 47 projecting laterally from the bar into a vertical slot 47<SP>1</SP> in the lever remains at the lower end of the slot. The extent of swing thus produced indirectly in the pivoted upstanding arm 40 is limited by a stop screw 49 at its lower end, and this is followed by further movement of the operating lever 42 due to continuing vertical movement of the bar 46. Screws 52, 53, 53, on the operating lever 42 are thus brought into abutment with rearward wings on the pivoted fingers 37-39, causing the fingers 38, 39 to swing inwardly upon the leading-in wires 5, 6, while finger 37, which is pivoted in a vertical slot in the vertical arm 40, swings in opposition to a tensioned spring 54, Fig. 10, into a raised position beneath the centre of the filament, Fig. 5 (not shown). The filament is now in a slightly tensioned condition. The next operation is effected by a shoe 58 located on the opposite side of the mount from the main parts of the fingers 37-39 and arranged to be moved inwardly to bend the filament-supporting wire 8 towards the plane of the leading-in wires 5, 6, the hook 10 in the end of the wire 8 being pushed into a slot 59, Fig. 11, in the end of the finger 37, so that it assumes a position below the top of the filament loop. The shoe 58 extends from a bell-crank lever 60 pivoted within lugs on the standard 41 and operated by the upper end of the vertical bar 46 abutting against a screw 62 in the rear end of the horizontal arm of the bell-crank. This action takes place after the operating arm 42 has reached the limit of its movement, so that the pin 47 moves within the slot 47<SP>1</SP> and the spring 48 becomes tensioned. The end portion 11 of the supporting-wire 8 is next lifted upwardly by a prong 64 on the end of an arm 63 which is swung arcuately down from a position at one side of the mount to engage it with the end portion 11 and is next moved upwardly to cause the open hook 10 to embrace the filament. Swinging movement is imparted to the arm 63 by mounting it on a shaft 65 carrying a pinion 69, Fig. 12, on its inner end and in engagement with a vertically movable rack bar 66 which is guided within the standard 41, its movement corresponding with that of the operating bar 46. The subsequent upward movement of the arm 63 is effected by the upper end 70 of the rack bar 66 (beyond the toothed portion 68) bearing upon a stop-screw 71 in a slide-block 72 which supports the shaft 65 of the lifting-arm and is forced upwardly. During the operations referred to the hook 10 of the supporting-wire 8 is partly closed around the filament 35 by pressing it between the prong 64 of lever 63 and a die 78 which is fixed on the bell-crank 60 and brought into position by the inward swinging of the latter when the end shoe 58 comes into operation. The closure of the hook 10 is completed and the wire 8 bent towards the vertical by inward movement of the shoe 58 and still further upward movement of the lever 63 and prong 64 thereon, this being effected by upward movement of the slide block 72 bringing a push pin 79 thereon into abutment with a screw 80 on the lever 60 and tilting the latter. The final form of the mount is shown in Fig. 7. In a modification a smaller type of mount provided with two intermediate filament-supporting wires is operated on. Specifications 264,805, [Class 39 (ii)], and 533,820 are referred to.