GB512159A - Improvements in and relating to apparatus for producing ground and polished glass strip - Google Patents

Abstract

512,159. Grinding and polishing glass. PILKINGTON BROS., Ltd., WALDRON, F. B., and GRIFFIN, J. H. March 31, 1938, No. 9836. [Class 60] In apparatus for producing a ground and polished strip of glass from a supply of molten glass, means are provided for treating the edges of the strip to prevent breakage of the strip by the grinding-tools and to avoid cutting or scraping of the polishing-felts. Molten glass 1 issues from a tank 2 and is formed into a strip 3 by rolling apparatus 4. The strip then passes through a lehr 5 to'grinding-tools 6, operating on both surfaces of the strip, and from the tools 6 to polishing-tools 7. The strip, as it is formed, may have curled edges 19 on its upper or lower face, and to avoid breakage of the strip by the first grinding-tool, the edges of the strip may be cut off, leaving a rectangular edge 9 with sharp corners 10. After grinding down to the lines 11, the corners are still sharp, and to avoid injury to the polishing-felts, the corners are bevelled as at 12 to a depth below the lines 11 by means of face grinding-discs 17 mounted adjustably with driving motors 14 on a frame 16, which may be placed at any point before the polishing- apparatus. When the edges of the strip are not cut, the curled edges 19 are ground down by discs 17 substantially to the line 20, Fig. 3, which may form a slightly bevelled edge. The sharp corners 21 are then bevelled by further grinding- tools as. described above; alternatively the part 19 may be ground by one tool to form bevelled surface 22 extending below the line 11, Fig. 7.