GB531515A - Improvements in or relating to process and apparatus for bending glass sheets - Google Patents

Abstract

531,515. Bending glass sheets. STEVENS, A. H. (Pittsburgh Plate Glass Co.). July 25, 1939, No. 21584. [Class 56] A method of bending a glass sheet comprises applying pressure to its surface by a series of flexible members which force the sheet, when softened, to take up the desired curvature. The sheet 32, Fig. 2, is suspended by tongs 35 from a bar 30 having the curvature to which the sheet is to be bent. The sheet is embraced by two sets of wires 37, 38 which are fastened to the bar 30 and also pass through holes in a bar 31 that is curved similarly to the bar 30. The sheet displaces some of the wires, as shown in Fig. 5, and pressure is applied to the sheet by weights 39, 40 attached to the wires. The bars 30, 31 form part of a frame which runs in an overhead track through a suitable furnace by which the glass is softened. The pressure of the wires bends the sheet to the curvature of the bars 30, 31, and the bent sheet can be annealed or cooled as required. Springs may be used instead of weights to tension the wires. If desired, the wires may be arranged all on one side of the sheet with a fixed template on the other side, and in this case the wires may be horizontal. The wires may be replaced by bars or metal grids which are flexibly supported at their upper ends and are yieldingly forced towards one another by their own weight, or by weights or other suitable means applied to their lower ends.