Improvement in fabricating bent laminated assemblies

• Main Author: ATKESON FLORIAN VICTOR
• Format: Patent
• Language: English
• Published: 25.03.1958
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; GLASS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES; METALLURGY; MINERAL OR SLAG WOOL; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

788,770. Shaping glass. PITTSBURGH PLATE GLASS CO. Feb. 20, 1956 [March 2, 1955], No. 5146/56. Class 56. In a method of preparing glass sheets for lamination into curved shapes by simultaneously subjecting the sheets to glass softening temperatures while mounted on a single glass shaping mould, the sheets are subjected to different thermal histories so that they have different internal viscosities before they are bent. Preferably the upper sheet 10, which may be thicker than the lower sheet 12, is first tempered to reduce its viscosity and is then mounted over the sheet 12 on the shaping mould M, a suitable separating or parting material 14 such as mica or diatomaceous earth being applied to the upper surface of sheet 12. For sheets of equal thickness, a partial temper may be imparted to the lower sheet and a more severe temper to the upper sheet. For the curved windscreen 20 comprising sheets 22 and 26 of glass and thermoplastic transparent interlayer 24, sheet 22 will be tempered if a male mould is used, but sheet 26 if a female mould is used, the tempering ensuring even and intimate contact between the sheets 22, 26 over the varying curvatures 30 and 32 and over similar varying curvatures at right angles to the section shown.