GB594911A - Improvements in and relating to methods of bending glass tubes and apparatus therefor - Google Patents

Abstract

594,911. Bending glass tubes. BRITISH THOMSON-HOUSTON CO., Ltd. July 3, 1945, No. 16936. Convention date, July 8, 1944. [Class 56] Apparatus for bending glass tubing comprises means for heating the tubing to a pliable state and an associated, re-shaping mould comprising a concave trough-shaped surface formed with a tube - receiving groove and means for pushing the pliable tubing against and through the groove. As shown, glass tubing 1 supported by grooved rollers 2 is guided towards the double set of grooved feed rollers 3, 3<1> and 4, 4<1> which are rotated by an electric motor 8. The tubing 1 is fed through an electric oven 19 where it is heated to a temperature 100‹ C. or so below its softening point. It then passes beneath an electrically heated shoe 21 mounted on the end of the oven, to a pair of power-driven grooved rollers 22, 23 which guide the tube to the mould 24, which is hollowed out on the side facing the tubing to form a concave semicircular cavity 36 with a tube receiving groove 37 of arcuate form. The upper end of the groove 37 is aligned tangentially with the tubing 1 as it emerges from between the rollers 22, 23. Where the groove 37 is of helical form, the mould is disposed at an angle, relative to the straight tubing 1 corresponding to the pitch of the groove. Before entering the groove, the tubing is subjected to supplementary heating by gas burners 32, 33 and is guided and supported in entering the groove by a roller 38, located immediately inward of the groove 37. A revolving cylinder mounted adjacent to one side of the mould may be provided to pick up the helically coiled tubing. The various parts of the apparatus are mounted on brackets fastened to a table 7.