GB282057A - Improvements in the manufacture of electric incandescent lamp bulbs from glass tubing - Google Patents

Abstract

282,057. General Electric Co., Ltd., (Assignees of Patent-Treuhand-Ges. fiir Elektrische Gliihlampen). Dec. 9, 1926, [Convention date]. Blowing ; forming electric-lamp bulbs.-Relates to a machine for making electric lamp bulbs from glass tubing, short lengths or even scrap pieces of tubing being used. The tubes are carried by a rotatable head and their ends, after being heated, are pinched together and closed by a tool. The closed ends are then rounded and finally are blown to shape in a mould. The machine comprises a vertical pedestal 2, Fig. 1, enclosing a hollow shaft 3 which carries a ring 4, having projecting radial arms, that forms the rotatable head. Carriers 5, for holding the glass tubes, are secured to the head and each carrier is constructed as a spring-closed chuck of usual construction. Each carrier is also provided with a pinion 6 which engages a gear wheel 8 secured to a shaft 7 passing through the hollow shaft 3. A suitable gear is provided for rotating the head 4 step by step, and the movement of the head conveys the glass tubes 9, held in the carriers 5, through eight working-positions A - - H, Fig. 5. After being loaded into the carrier at A, a tube is conveyed to position B where its lower end is heated by burners 10. At the next position C, the lower end is seized by tongs 11 which pinch and close the heated part of the tube and then draw off the lower end, the drawn-out part, 11<1>, of the glass being heated by burners 10<1>. The tongs 11, Fig. 1, are pivoted on the upper end of a rod 15 which slides through a vertical tube 16 and is raised and lowered by an arm 22 operated by a cam. The tongs are raised to their uppermost position and when they are lowered again, they grip and draw off a part of the tube. The closed end of the tube is reheated and rounded at position D, Fig. 5, by burners 25, and air under pressure may be admitted to the tube to assist in shaping the end. At the next position, E, a die. 33, mounted on the end of a vertical rod 27, is moved upwards against the lower end of the tube to cause it to bulge laterally. The rod 27 is drawn downwards by a spring and is lifted to bring the die against the tube, by a cam. The rising part of the cam is serrated so that the die shapes the end of the tube with a succession of taps. At the next position, F, the bulbous end of the tube is reheated by burners 34 and is next blown in a mould 35 at position G. Finally, at position H, the carrier 5 is opened and the finished bulb is discharged.