Method of and apparatus for shaping sheet material

摘要

880,155. Shaping glass sheets. COMPAGNIE DE SAINT-GOBAIN. Feb. 18, 1958 [Feb. 18, 1957], No. 5315/58. Class 56. In shaping glass or like sheet material, as for "wrap around" windscreens, the sheet is rendered plastic, disposed adjacent a rigid mould of desired shape and pressure applied to the periphery only of the sheet to shape the sheet, the pressure being applied first to the portions of the periphery at the central zone and then to the remaining portions of the periphery progressively outwards to each end of the sheet. A convex mould 1 of sheet steel has a central large radius cylindrical surface 2, conical intermediate surfaces 3 and terminal plane surfaces 4, the surfaces being covered with a spun glass fabric to prevent sticking. The mould 1 has adjustable stops 5 to engage a deformable mould 11 and is formed with recesses 6 to receive the glass sheet suspension means. The deformable mould 11 is formed by rigid strips 7 to 12 of metal covered by spun glass fabric, the strips 7, 8, 9, with gaps 13 corresponding to the recesses 6 for the glass suspension means, the end strips 11 and a single lower central strip 12 (not shown) being straight in the plane of the figures and the strips 10 corresponding to the surfaces 3 being normal thereto. The strips 7-12 are secured to supporting members 14, 15, 16 by means of adjustable rods 17, the members 14, 15, 16 being pivoted together at 181-211 along axes XX1 and YY1. The strip 10 may be made of rubber, backed by the steel strip and enclosed in spun glass fabric, so as to be more easily bent by adjustment of rods 17 to the required shape. As shown in Fig. 1, the mould 11 is carried by a shaft 28 secured to members 14 for movement towards the mould 1 to press the centre section and pressure is then applied to the end of members 16 by hydraulic units 33 which urge the sections 10, 11 towards the mould 1, the members 15, 16 being joined by springs 27 powerful enough so that the sections 10 engage the section 3 before the end section 11 engages the section 4. Counterweights 29 (not shown) passing round pulleys 31, 32 and the springs 27 return the mould 11 to its opened out position for receiving the glass sheet 22. As shown in Fig. 4, the sections 10, 11 are moved by rack and pinion units 34, 35 and 341 351, the pinions 34, 341 being secured to shafts 36, 38 which constitute the pivots 191, 181, the shafts being interconnected by a member 37 pinned to shaft 36 and rotatable on shaft 38. A similar member 39 is pinned to shaft 40 and rotatable on shaft 41 which constitute pivots 211, 201, the members 37, 39 being braced by a stirrup 42. In a further embodiment, the strips are supported by box-like members pivoted together and connected by bellows, each pair -interconnected by a pipe with valves so that the intermediate sections move before the end sections.