GB1316417A - Process and apparatus for the manufacture of sheet glass - Google Patents

Abstract

1316417 Drawing sheet glass GLAVERBEL 7 Sept 1970 [10 Sept 1969 29 July 1970] 44650/69 and 36764/70 Heading C1M In the drawing upwardly of a ribbon of glass from a bath of molten glass, components which are located near to but normally out of contact with opposite faces of the ribbon form part of a signalling system which yields a signal in the event that the portion between the components moves by at least a certain minimum distance out of a predetermined plane. As shown in Figs. 1 and 2, glass sheet 1 drawn upwardly by rollers 5, 5<SP>1</SP> from molten glass 2 has conventional coolers 16, 16<SP>1</SP> and edge rolls 17, 17<SP>1</SP> adjacent the meniscus and, just above, the signalling components comprise electrodes 18, 18<SP>1</SP> with extremities close to the opposed faces of one or both margins, the electrodes 18, 18<SP>1</SP> forming part of a signalling system 19, 20, 21 which may give an audible or light warning 24, 25 and preferably also operates movable rollers 6<SP>1</SP> and 7<SP>1</SP> which, with fixed rollers 6 and 7, grip the buckling sheet 1. In alternative constructions, plate electrodes which may be internally cooled may replace the electrodes 18, 18<SP>1</SP> or, as in Fig. 9, the electrodes are replaced by a pair of tubes 83, 83<SP>1</SP> which discharge gas against opposed margins through tube ends 85, 85<SP>1</SP> just above the edge rolls 84, 84<SP>1</SP>. Buckling of the glass sheet 79 causes variations of the gas pressure in the tubes 83, 83<SP>1</SP> which have flow restrictors 90, 90<SP>1</SP> through which a constant gas pressure is maintained from pipe 91 and regulator 92, the inner part of tubes 83, 83<SP>1</SP> being connected by tubes 93, 93<SP>1</SP> to a measuring instrument 94 which emits a signal on variation of pressure to give audible and/or visible signals and also brings into operation the rollers 6, 6<SP>1</SP> and 7, 7<SP>1</SP> so that the broken sheet shall not foul the tube ends 85, 85<SP>1</SP>. Suitable electrical circuits are disclosed. The electrodes are preferably of refractory steel or may be of very high melting glass, or a carbide, nitride or silicide.