GB741450A - Improvements in or relating to methods of and apparatus for bending glass tubing - Google Patents

Abstract

741,450. Bending glass tubing. GENERAL ELECTRIC CO., Ltd., and HAINES, E. M. July 22. 1954 [July 23, 1953], No. 20500/53. Class 56 For bending into arcuate or circular shape a length of glass tubing, particularly the envelope of a tubular electric discharge lamp, the tubing 2 is heated in ovens 3, 4, to a plastic condition and its elongation sets into operation an electric motor 32 which causes a carriage 27 to advance so that two axially-separable discs 23, 24 forming a drum 22 come into the path of the lower end of the tubing. The tubing becomes automatically latched to both discs in the annular periphal groove formed between them. The drum is now rotated about a stationary axis and the holder 10 for the upper end of the tubing is simultaneously lowered, by mechanism operated by the same motor, so that the tubing wraps itself -round the drum. During this action inert gas at increased pressure is fed into the tubing to maintain its circular cross-section. When the drum has rotated through nearly 360 degrees the top end of the tubing becomes released from the holder 10 and becomes automatically locked to both discs of the drum which is now thereupon retracted from the ovens. The bent tubing is now unlatched from the disc 24 and is carried solely by the disc 23 which is now removed from its carriage. The bent tubing is finally released from the disc 23 which is then repositioned on the carriage for the next operation.