GB857101A - Improvements in or relating to glass tubing for the manufacture of bulbs and to apparatus for producing such tubing - Google Patents

Abstract

857,101. Glass manufacture. PELLETIER, G., and FINCK, M. March 26, 1958 [April 25, 1957], No. 9745/58. Class 56. A stock piece of glass tubing of great length, adapted to be used in bulb-making machines for forming bulbs by treatment of successive sections of its length when placed vertically in the machine, has one end closed and the other end open by a small orifice, whereby it is strengthened during manipulations by the closed end and released from overpressures during bulb making by the small orifice arranged uppermost and acting as an outlet for rising hot hair. Open lengths of tubing 10 are conveyed by a ramp 13 from a drawing machine 14 to a vertical conveyer 15 which receives them in uniformly-spaced holding means such as jaws. A conveyer 16 moving at the same spe as conveyer 15 carries drawing clamps 17 each side of the tubing 10 and controlled b springs 18 and cams 19 to move the clamps apart to draw the tubing where it is softened adjacent each end at 35 by burners 20, to close the tube. Knives 36 are arranged to separate the ends 26 sharply from the main tube, the ends being deposited in shoots 25. The row of burners 20 move with the tubing 10, each burner comprising two semi-circular elements all mounted on two oscillating frames 21 which move upwards with the conveyers 15, 16 while the burner elements approach and surround the tubing 10 to soften the glass and have a rapid return travel with the burner elements separated. The frames 21 are carried by levers 22 rotating about spindles 23 in a complete circle, part of the movement being slow and the rest fast. One of the frames 21 also carries burners 24 to form a small hole at one end of the finished tube. The tube then passes through a cooler 27, a reheater 28 to anneal the tube and another cooler 29 and one end of the tube is then marked at a unit 30, similarly mounted to the burner unit, having spray guns 31 charged with colouring material, or plugs, rollers or other means for leaving a trace on the tube end as it passes, the mark being heated if necessary to render it indelible.