GB810379A - Moulds for forming curved glass panes - Google Patents

Abstract

810,379. Shaping glass sheets. SHATTERPROOF GLASS CORPORATION. Feb. 5, 1957, No. 3994/57. Class 56. A mould for forming curved glass panes comprises metal strips 3, 10 extending along opposite sides and around the ends thereof and having top edges 4, 11 that provide a continuous marginal shaping surface to conform to the convex face of a curved pane A adjacent its margin and relatively light braces 6, 12 extending across the mould below the top edges 4, 11 and connected to the strips 3, 10, the braces being formed of a metal having a coefficient of expansion less than that of the strips 3, 10. Cord rolled steel is used for the strips 3, 10 and the braces 6, 12 and stiffening trusses 7, 9 for the strips are formed of stainless steel tubes. The strips 3, 10 are tightened by spaced openings 5, 13 and the strips, braces and trusses are joined by welding. The mould has conventional central and end sections 1, 2, 2, each end section 2 being mounted on the frame 16 by links 19 pivoted at 20 to posts 18 and carrying a transverse shaft 21 extending through brackets 22 on the section 2, and hinged to the central section 1 at 14, the hinges being below the top edges of the strips 3, 10 and such that the end edges of the strips 3, 10 abut when the end sections 2 are in their uppermost, moulding position. The pane or panes A are supported at each end on plates 27 secured to the strips 10 and by four L-shaped supporting members 39 with a facing 41 of material of low heat conductivity, each member 39 being suspended by a pivot 40 for end posts 38 of an arm 36 having forked ends 37 journalled on a pin 34 projecting from plates 35 welded to the bottom edge of strip 3. A shaft 42 on each arm 36 carries a grooved roller 43 to engage a cam 44 or 45 on the end section 2, the cams 44, 45 being spaced therefrom and laterally inclined with respect to the side strips 3 so that a lateral movement is imparted to the panes A as they are lowered into engagement with the mould, so as to obtain accurate alignment of the pane which is given a sharper bend at one side of the mould. The cams 44, 45 are so shaped that as the glass is softened and the supporting members 39 pressed down thereby, the central section 1 is moved downwardly so that the members 39 only move below the top edges 4 just before the section 1 reaches its lowermost position. The central portion of the glass may be protected from overheating and sagging by a sheet of asbestos 15 supported on the cross braces 6. Specification 810,380 is referred to. Reference has been directed by the Comptroller to Specifications 678,708 and 727,200.