GB891293A - Improvements in methods of and apparatus for rolling flat glass - Google Patents

Abstract

891,293. Glass manufacture. PILKINGTON BROS. Ltd., and LIGHTFOOT, W.A., March 18, 1960 [March 23, 1959], No. 10029/59. Class 56. A casting roll used in the manufacture of flat glass in continuous ribbon form is corrected for distortions occurring as a result of heating by sensing the distortions and directing cooling streams along a generatrix in volume proportional to the distortion sensed at any time. In the apparatus shown in Fig. 1, the glass ribbon is formed between rolls 1, 2 carried in bearings in headstocks 7 supported on beds 8 at the ends of a beam 9. The roll 1 is driven through gearing 10 and drives the roll 2 through gearing 11. Distortions of the lower roll are sensed by mechanism carried on a box 15, forming a bridge between the beds 8, through which water is circulated. The mechanism comprises a lever 21 (Fig. 3) pivoted at 20 and carrying a carbon feeler 22 which bears on the lower roll. The pivot 20 is slightly eccentric and can be rotated to adjust the feeler 22, to take up wear, by turning a handwheel 42 which drives through a shaft 42a (Fig. I) gearing 38a, a shaft 38 and gearing 37, 39. The other end of the lever 21 is coupled to the stem of a valve 24 which controls the supply of air from a pipe to a pipe 26 feeding a pipe 27 having nozzles to direct it on to the roll 1. A certain minimum flow is always allowed to pass. The pipe 27 is suspended between arcuate plates 74 secured to other arcuate plates 76, carried on standards 28, by screws in slotted holes. The pipe 27 is thereby adjustable circumferentially of the roll 1. The pipe 27 may be integral with another pipe, parallel to it, through which the air first passes and which is water jacketed to cool the air. Distortions of the roll 2 are sensed by a feeler 22 (Fig. 8) carried at the end of a tube 48 supported for axial movement so that the end 50 actuates the lever 21 to operate the valve 24 to supply air to the pipe 27. The tube is carried by flexible members across the ends of a tube 51 carried on trunnions 53 and pivotally adjustable by set screws 59. The trunnions are pivoted in brackets 54 on a carriage 55 running on a track 57. The air pressure supplied from the valve 24 is indicated by a pressure gauge 43. If the pressure falls below or uses above limits indicated by contacts 68, 69 a May 67 is operated to run an electric motor 66 which, through a screw 64, drives the carriage 55 towards or away from the roll 2. The time for which the motor runs is determined by a time switch 70 operated by a dimetallic strip. Specification 722,554 is referred to.