GB865550A - Improvements in or relating to sealing-in machines for the manufacture of electric incandescent lamps and similar devices - Google Patents

Abstract

865,550. Making electric incandescent lamps. GENERAL ELECTRIC CO. Ltd. Nov. 25, 1959 [Nov. 26, 1958]. No. 38104/58. Class 39(2). [Also in Group XXIII] A machine for sealing the foot-tubes to the bulbs in electric incandescent lamps or similar devices, comprises a movable support member carrying a plurality of holders each supporting a foot-tube and a bulb in sealing relation and a plurality of heating means each travelling along with one of the holders, means for moving the support member at uniform speed in a closed path and means for automatically initiating the heating at a first position along the path of travel and terminating it at a second position after the foot-tube and bulb are sealed together. Preferably a co-operating mould which may be in the form of two halves is also carried by the support member along with each holder and moved into contact with the neck of the bulb for shaping the glass after sealing. The foot-tubes 4, Fig. 3, are supported on rods 11 which can be vertically reciprocated relative to the main support by cam means. The bulbs 5 are fed on to cradles 13 so that the neck embraces the foot-tube and are gripped by jaws 29. After loading, the rods 11 and cradles 13 are rotated by gearing driven from the main support. Heating is effected by a plurality of burners 10 carried by the main support and associated with each holder, the supply of coal gas and air, for heating being controlled by a valve operated by a cam, a by-pass being provided to prevent extinction of the flame when the main supply is cut off by the cam. After heating has ceased, a rod 62 having teeth 63 engaging a gear segment 65 on an arm 60 is raised, thereby bringing the end of the arm 60 over the bulb 5. The arm 60 carriesinter-geared arms 6 terminating in moulds. When the arms 6 are in position, compressed air is admitted to a cylinder 77 moving a piston 76 to bring the arms 6 into contact with the neck of the bulb against the bias of a spring 78. The jaws 29 are carried by bell-crank levers 32, Fig. 5 (not shown), coupled together and pivoted on arms 39, Fig. 5 (not shown), extending from a cylindrical support 40, Fig. 4, slidably mounted on a rod 41. A spring 85 biases the jaws 29 to closed position. Before a bulb is loaded into the holder, a cam operated rod 47 raises the support 40 causing the jaws to open against the spring 85. After loading, the rod 47 is lowered and an arm 48 on a bell crank lever engages under the support 40 retaining this in raised position after the spring 85 has caused the jaws 29 to close on the neck of the bulb. After sealing is complete, a trigger 52 carries by a cam-operated rod 54 engages the other arm 55 of the bell crank lever, releasing the support 40 which falls under gravity, stretching the neck of the bulb and severing the portion below the seal. The next upward move of the rod 47 releases the severed portion which falls down shoots 57, 58 into a suitable receptacle. If desired, the sealing heads may be arranged in pairs with the operating members common to each pair. Instead of controlling the flames of the burners, they may be mounted so as to be moveable into and out of operative position at the beginning and end of the heating period. To prevent oxidation of the filament during sealing, clean dry nitrogen may be fed into the bulb through a bore in the rod 11.