GB468941A - Improvements in and relating to methods of and apparatus for perforating glass bodies - Google Patents

Abstract

468,941. Perforating glass. BRITISH THOMSON-HOUSTON CO., Ltd. March 18, 1937, No. 8010. Convention date, March 18, 1936. [Class 56] A method of perforating a glass body consists in heating a portion of the glass to render it plastic, and then applying suction to the heated portion to remove the softened glass and form an opening. The method is particularly suitable for forming openings in the walls of a bulb 12, Fig. 3, used for the manufacture of a vaporizing device containing an electrically heated filament. Part of the wall of the bulb is heated by a gas flame, and the softened spot on the glass is pressed inwards and shaped by a tubular punch 19. Suction is then applied to a passage 21 which runs through the punch, and part of the glass is drawn into the passage and broken. The punch is now withdrawn, and the aperture in the glass is shaped and smoothed by the insertion of a second punch. The method can be carried out by a machine comprising a turret 10, Fig. 1, which is provided with pockets 16 for the bulbs, each pocket having an aperture in the wall to allow access of gas flames and the punches. The turret rotates step-by-step and carries the bulbs past burners 17, 18, and sliding supports 25, 32 in which the punches are mounted. The bulbs are removed from the turret by air jets, from nozzles 33, 34, which lift the bulbs into a shoot 35.