Patent GB-751376-A (GB)
Title: Mount sealing apparatus for tubular electric lamps
IPC: H01J5/24
Filed: 1954-02-01
Abstract: 751,376. Making tubular electric lamps. SYLVANIA ELECTRIC PRODUCTS, Inc Feb. 1, 1954 [Jan. 30, 1953], No. 2986/54. Class 39(2). Apparatus for sealing filament-carrying mounts simultaneously to both ends of a vitreous lamp tube comprises a conveyer which moves through a predetermined path and carries a series of heads each supporting a pair of mounts with a lamp tube located coaxially between them, means being provided for rotating each lamp tube and the pair of mounts in engagement with its ends, and heating means for fusing the mounts to the ends of the tube. The apparatus comprises an angle-iron frame 20, Figs. 1 and 2, upon which are mounted a pair of spaced endless chain conveyers 22 arranged longitudinally and carrying between them a succession of transverse heads 24, the two end portions of each head being provided with a rotatable cradle forming an end support for a tube 11 which is retained in position by a spring-pressed finger 170 intermediate its ends. Adjacent to each cradle a retractable mount spindle 252, Fig. 9, located coaxially with a tube supported therein is arranged for axial movement to permit a mount to be fed automatically into position between the end of the tube and the mount spindle. Each cradle comprises a fixed end plate 168, Fig. 5, upstanding from the bed plate 156 forming part of a head 24 and apertured to form a journal for a gapped pinion 164 rotatably mounted therein, the end plate 168 being also gapped to allow the end of a tube to be dropped through to a seating at the bottom of the U-shaped gap in the pinion when the two gaps are aligned and a toothed sector 188 pivoted on the pinion 164 is in its retracted position, as shown. The sector is moved automatically either to open the gap or to close it and complete the toothed circumference of pinion 164. During the progress of a head 24 from the feeding end of the machine at which the ends of a tube are inserted either manually or automatically on to the seatings of the gaps in the pinions 164, the closed gears 188, 190 are driven by a gear wheel 204 mounted on a shaft 206 connected by an annular friction clutch to a sprocket wheel 208 which is driven by an endless chain 212, Fig. 1, carried between shafts 216, 218. At the loading and unloading positions the annular clutch is caused to slip by a pawl 234, Fig. 5, being brought into engagement with a single-toothed ratchet wheel 232 mounted on shaft, 206, operation of the pawl being effected by a spring-loaded lever 240 carrying a cam roller 242 associated with a longitudinal cam track 244, Figs. 1 and 5. Mount-feeding mechanism. Mount-feeding mechanisms on opposite sides of the machine at the tube-loading end are driven by separate similar mechanisms each comprising a gear wheel 49, Figs. 1 and 2, on the idler shaft 34 of the conveyer' 22, connected by a gear wheel and chain and sprocket system 52, 54, 56, to drive a shaft 60 carrying a wheel 68 around which is passed an endless metal band 64. The band 64 also passes around a pair of horizontal guide wheels 76 and an interposed vertical guide wheel 80, each guide wheel being channelled circumferentially to receive the band and accommodate bosses 74, Fig. 10 (not shown) provided at intervals on the underside of the band to engage similarly spaced notches in the channel of the wheel 68. Clips 66 are secured at intervals along the band 64 to receive mounts which are inserted therein in any desired manner, the spacing of the clips being calculated to ensure that a pair of mounts is brought into register with the longitudinal axis of a tube in the cradle of a head 24, this being facilitated by inclining the guide wheels 68, as shown in Fig. 1, so that the bands 64 carry the mounts inwardly towards the ends of the tubes. When the filament of the mount becomes positioned adjacent to the open end of a tube the mount spindle 252 forming part of the mechanism at the end of a head 24 is moved longitudinally along its axis so that its cylindrical end encompasses the exhaust tube 15 and leading-in wires 17 of the mount, this movement being produced by an angularly disposed cam track 264, Fig. 1, engaging a roller 262 on a vertical pin 260, Fig. 4, upstanding from a horizontal sleeve 248 within which the mount spindle 252 is located. These devices are duplicated at opposite sides of the machine. Variation of the end thrust on the mounts at various stages of the heating cycle is obtained by a bell-crank 278, Fig. 3a, one end of which is bifurcated to engage a peripheral groove in the sleeve 250, Fig. 4, the other end having a cam follower 282 which rides upon tracks 296, 298, Fig. 1, arranged to retract the sleeve 250 at the beginning and end respectively of the travel of the head. During the sealing cycle the mounts are rotated by coaxial gear wheels 256, Fig. 3a, mounted upon the sleeve 250 and driven by a gear 254 on the rotating shaft 206 carried by the head 24. Burner arrangement. The-two banks of heating units 26, Fig. 1, one along each side of the apparatus, each comprise a plurality of burners 84 mounted on a burner-supporting rod 88, Figs. 2 and 3a, extending the length of the frame 22. The outer end of each burner is connected by a flexible tube 90 to a rigid tube 92 mounted on, and bridging a coal-gas manifold 94 and oxygen manifold 96 connected to supplies of those gases. The burner-supporting rods 88 are rotated about their axes to bring the series of burners 84 into heating relationship with the ends of the lamp tubes and then reciprocated longitudinally, their return movement being effected after the burners have been elevated out of the path of the lamp-holding heads 24. The longitudinal movement of. the burner-supporting rods 88 is effected through a pivoted rocking arm 114, Fig. 2, carrying a cam roller which engages within a slot in a cam disc 110 connected by a bevel gear drive 108, 104 to the end of a rotating shaft 102, the free end of the arm 114 being linked by a connecting rod 118 and levers 120, 126 to a universal coupling 130 on the end of an extension 128 of rod 88. The oscillatory rotary motion is imparted to each rod 88 by a rocking lever 146, Fig. 3a, one end of which engages a grooved cam 142 on shaft 102, whilst the other end is linked to a radial arm 152 on the rod 88. The softened glass of the seal between the flare of the mount and end of the tube is shaped by a puddling device comprising a wheel 304, Fig. 3a, rotatably mounted at the upper end of a lever 300 and arranged to be brought into contact with the peripheries of the flare and end of the lamp tube by a roller 306 engaging a longitudinal cam track 308. Specifications 625,409 and 672,494, [both in Group II], are referred to.