GB419747A - Improvements in glass polishing tools - Google Patents

Abstract

419,747. Polishing flat sheets of glass. PILKINGTON BROS., Ltd., 703, Tower Building, Water Street, Liverpool, and WALDRON, F. B., Norwood, Eccleston Park, Prescot, Lancashire. May 19, 1933, No. 14524. Addition to 407,406. [Class 60.] Apparatus for polishing flat glass comprises a number of polishing-tools 3 operating on the glass 4 and each carried by a shaft 5 rotatable in a frame 1 driven by a shaft 2. The shafts 5 are each supported by a thrust bearing 7 carried by a flexible disc 8 held by a ring 9 to a casing 10 supported by the frame 1, and each casing is supplied with pressure fluid from a ring pipe 12 by a pipe 11, the pipe 12 being in communication, through a bore 14 in the shaft 2 with a supply main 17 having therein a valve 18 and a discharge valve 19. In operation, the valve 19 is closed, fluid is admitted by the valve 18 to the casings 10, which moves the tools up to the glass ; the valve 18 is then closed, the fluid supporting the tools and allowing them to yield owing to unevenness of the glass, thereby maintaining equality of pressure among the tools. The tools can be raised or lowered by operation of the valves ; when operating on vertically placed glass, spring pressure may be used to move the tools away from the glass. Other forms of press may be used, for example, plungers in cylinders ; the tools may be of different sizes, the relative pressures on the glass being given any desired values by variation of the areas of the discs 8.