Patent GB-754032-A (GB)
Title: Improved apparatus for mounting filaments for incandescent electric lamps
IPC: H01K3/10
Filed: 1954-05-31
Abstract: 754,032. Making electric incandescent lamps. BRITISH THOMSON-HOUSTON CO., Ltd. May 31, 1954, [June 1, 1953], No. 16094/54. Class 39(2). In apparatus for mounting relatively long filaments 15, Fig. 2, upon the ends of leading-in wires 8, 9 extending from a stem 2 and for attaching to the filament the ends of supporting- wires 10, 11 projecting radially from an arbor 12 extending axially from the stem, the stems are mounted upon a conveyer 3, Fig. 1, which indexes them through a plurality of work stations disposed adjacent to their path, one work station A having mechanism for presenting a filament with its ends suitably disposed for attachment to the leading-in wires, and the succeeding station. B having means for positioning intermediate portions of the filament for attachment to certain supporting wires by curling the ends of the latter around the filament, the remaining supporting wires being curled about other portions of the filament at station C ; the leading-in wires and supporting wires may be angularly re-located at stations D and E. The conveyer 3 is of the endless band type with a series of pairs of jaws 3<SP>1</SP>, 3<SP>1</SP> which grip the exhausting tube of a stem 2 and hold the latter with the arbor 12 and leading-in wires 8, 9 directed downwardly. The filaments are preferably fed automatically to station A by the step-by-step mechanism described in Specification 714,543 which places the foremost filament 15<SP>1</SP> upon a pair of transfer arms 17, Figs. 6 and 7, each mounted on a shaft 35 and arranged initially in longitudinal alignment, to receive the ends of the filament in suction notches 16 near their extremities, the intermediate portion of the filament being supported on a ledge 33 extending from the feeding table 30. Suction is applied to the notches 16 through a tube 36 and flexible pipe 37 and the shafts 35 are swung around to bring the transfer arms 17 into the position shown in Fig. 6, thereby looping the filament and bringing its ends above loops 7, Fig. 2, at the ends of the leading-in wires 8, 9, whereupon the shafts 35 are lowered to bring the ends of the filament within the loops 7. The rotation of the shafts 35 is effected by interengaging pinions 52 secured thereon, and one shaft also carries a pinion 45 which is driven by a horizontally reciprocable rack bar 44 connected at its outer end to one end of a pivoted bell-crank the other end of which is linked to a rod controlled from the main cam shaft. A second vertical rod also reciprocated by a cam operates to lower a bracket supporting the shafts 35. The mechanism 14 which clamps the hooked ends of the leading-in wires upon the ends of the filament comprises a body 58, Figs. 6 and 7, mounted on a pivot pin 53 on a stationary base 54 and tilted forwards at intervals from an oblique inoperative position by a vertical push rod 60 which is linked to a slide 61 engaging the lower portion of the body 58. Clamping jaws 56, 57 mounted on the upper ends of a pair of levers are moved inwardly to press the hooks 7 upon a central anvil 55, the levers being mounted on a common pivot 59 and operated when the slide 61 is moved downwardly so that a cam 65 thereon is engaged between rollers 66 on the lower parts of the clamping-levers. When the stem with filament attached is indexed from station A looped part of the filament 15 is pulled off the ledge 33 of the table 30 and falls upon a guide plate 19, Fig. 1, extending substantially between stations A and B and forming part of a filament placing mechanism 21. The guide plate 19 is angularly disposed relative to the path of the conveyer, whereby the filament loop is pulled over to the opposite side of the stem 2 from the leading-in wires 8, 9 and, on arrival at station B, the filament loop slides on to a movable guide 20 located beyond the guide plate 19 and assumes the position shown in Fig. 11. The devices associated at station B comprise the movable guide 20 of the filament placing mechanism 21, filament positioning means 24, and the support wire bending and curling means 25 consisting of two heads 25<SP>1</SP>. Each bending and curling head 25<SP>1</SP> comprises a body 84, Figs. 11 and 13, provided with a frontal vertical horn 83 over which the loop of the filament 15 is passed prior to entering the wide mouth of a notch 26, the movable guide 20 operating to deflect the filament so that its loop is directly over the notches 26 of the two heads 25<SP>1</SP> on the opposite side of the stem from the leading-in wires 8 and 9. The means 24, 25<SP>1</SP> continue to move the filament upwardly whereupon the movable guide 20 is moved across the axis of the stem towards the plane of the leads 8, 9 so that further parts of the filament are carried over the two fingers of the positioning means 24 and then introduced into the notches 26 of the two bending and curling heads 25<SP>1</SP> on the leading-in wire side of the stem axis. This positioning movement is assisted by jets of air directed across the heads 251 from two air pipes 87 mounted on the rim 75 of platform 76. The air jets, which are raised simultaneously with the heads 25<SP>1</SP> are controlled from the main cam shaft and keep the filament 15 in a comparatively tight loop. The control finger 20, Figs. 1 and 11 is mounted on a hub 77 on a shaft 79 and is under the action of a torsion spring whereby an arm 90, Fig. 9 (not shown) extending radially from the hub is held in engagement with a stationary cam rod 91 so that downward movement of the shaft 79 ard its support causes the control finger 20 to be swung back clear of the leads 8, 9. During upward movement of the filament positioning means 24 the filament 15 also slides down the sloping upper ends 94 of two spaced fingers 23, Fig. 11, of the positioning means and into notches 95 therein, thus taking the form of a straight length between the fingers, whereupon the fingers, which are pivoted intermediate their ends on a collar 97 at the upper end of a vertical rod 80 are lifted by upward movement of the latter. The lower ends of the finger levers each carry a screw 99 spring-drawn into abutment with a block cam 98 which is slidable upon the rod 80 but connected to the collar 97 by a spring 101 secured to a yoked bar 103 extending laterally from the cam, so that during initial movement of the rod 80, the cam 98 and collar 97 moves simultaneously until the yoked bar 103 meets an abutment stop 105, whereupon the cam 98 is halted while the fingers 23 and their support continue to move upwardly relative to the cam surface. This causes the fingers to swing and pull the filament 15 outwardly to facilitate its entry into the narrow portions of the slots 26 of the bending and curling heads 25<SP>1</SP> and through a narrow slit in a spool 85, Fig. 13, into the open core of a mandrel 86. The lifting of the rod 80 is effected through a surrounding sleeve 81 and an interposed spring 108 at the bottom of the latter, the sleeve being linked to a cam-operated lever 117. With the lifting of the sleeve 81 a wide flange 123 on its upper end releases the downward pressure on'the platform 76 which supports the wirecurling means 25 and shaft 79, thereby allowing compressed springs 114 around four rods 112 to expand so that the curling means 25 and filament control finger 20 are lifted a limited distance at the same time as the rod 80. The rod 80 is halted when a yoke 106 on the collar 97 meets an abutment stop 107, but the sleeve 81 continues to rise, causing its flange 123 to bear upon the bottom end of a phmger 128 which extends through a vertical guiding cylinder and, at its upper end, is provided with a dog 130, Fig. 12, which is normally held downwardly on an ear 129 on a pivoted depresser arm 126 and holds the arm in a vertical position, Fig. 11, against the pull of a spring 131. The release of the pressure on the ear 129 allows the arm 126 to be pulled clockwise about its pivot 127 so that a depresser finger 125 on the end of the arm bears upon a filament support wire 10 extending radially from the arbor and bends it downward at a point adjacent the arbor button 27, and pushes its free end portion down between a control finger 133, Fig. 13, and a face plate 134 over the end of the body 84 of the bending head 25<SP>1</SP>, thereby causing the end of the wire to engage the mandrel 86. (The face plate 134 and control finger 133 are shown in Fig. 13 spaced from their normal position). Towards the end of the upward movement of the plunger 128 its cammed upper end engages the lower end of a lever 138, Fig. 13, carried on a pivot 139 and forces the lever inwardly against the control finger 133 and deflects it so that the end of the support wire 10 is caught by a projecting shoulder 136 on the spool 85. Further movement of the depresser arm 126, after the operation of the control finger, indents the intermediate portion of the support wire 10 extending between the arbor button 27 and mandrel 86 and bends it so that one portion is nearly parallel with the arbor and the remaining end portion is nearly perpendicular thereto in the plane of the mandrel 86 and filament 15, a final set being given to the wire by a finger 143 on the depresser arm 126. The curling of the free end of the support wire 10 about the filament 15 by rotation of the spool 85 is effected by rotation of the latter by a co-axial supporting pinion 146 driven by a gear segment 145 when a stud 147 on the vertical plunger 128 engages an arm 148 mounted on the shaft 127 and turns it against the action of a tensioned spring 149. The arm 148 is connected to the segment 145 by a cushioned coupling comprising a torsion spring 150 co-axial with the shaft 127 and with one end secured to a post 152 on the arm 148 and the other end secured to a post 151 on the segment whereby movement of the arm 148 effects the curling of the end of the support wire 10 about the filament. In the event of the filame