GB292448A - Improvements relating to the manufacture of sheet glass - Google Patents

Abstract

292,448. Frink, R. L. March 11, 1927. Divided on 291,883. Drawing.-In an apparatus for making sheet glass in a continuous ribbon, molten glass issuing from a tank furnace or other receptacle is carried across a free space to a moving carrier, and the speed of the carrier is automatically coordinated with variations in the rate of flow of the molten glass from the tank. The glass is drawn from a working-chamber 6, Fig. 1, which may be part of the furnace described in Specification 291,883. A horizontal slot 47, Figs. 1 and 2, in the wall 5 of the chamber 6 is fitted with two pivoted lip members 48, 49 which are rotatable, about horizontal axes 48a, 49a between side walls 56. The two members can be moved individually by means of a rack and worm gear, so that their outer ends can be adjusted in relation to the surface level of the glass in the container or to each other. Each of the members is provided with two or more electric heating circuits 53, 54 and the side walls 56 are similarly heated. The surfaces of the members which make contact with the glass preferably made of metal such as nickel or iron alloys, or they may be plated with chromium. The sheet formed by the flow of glass through the slot 47 is received, and carried away by, an endless conveyer 59 consisting of refractory slabs. 60 secured to sprocket, chains 61 and arranged within a heated chamber 58. The guides for the chains 61 are so shaped that a hump is formed in the conveyer, and the sheet is bent first in one direction and then in the other before it travels in a horizontal plane into an annealing chamber. Thus the stretching of the under surface of the sheet, caused by the sag between the slot and the conveyer, is compensated by the reversed curvature when passing over the humps. The sheet. before, it reaches the conveyer, passes between edge rolls 66 carried by an arm pivoted at 67 and arranged to operate a rheostat 70. Any variation in the curvatures of the sheet before it reaches the conveyer causes a variation in the speed of the motor driving the conveyer, and the curvature of the sheet is kept constant.