Apparatus for bending glass sheets
AssigneeLibbey-Owens-Ford Co.
InventorsDavid M. Wampler, Raymond L. Brandeberry, Ermelinda A. Apolinar, Timothy C. Holt
Life of this patent
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Abstract
The present invention relates to a female press bending ring for use in the press bending of glass sheets outside of a furnace, and more particularly to a female press bending ring which is suitably heated during the bending cycle to regulate the transfer of heat between the peripheral margin of the glass and the female bending ring with which it is in contact. By so doing, near-edge tension and edge stresses are greatly reduced, thereby reducing chill cracking and glass breakage during and after production. The female ring may be covered by a layer of fiberglass cloth or the like to provide a smooth resilient surface for engaging the glass sheet.
Claims9
In apparatus for press bending heated glass sheets to a predetermined configuration including a ring-type shaping rail having a shaping surface conforming in outline and curvature to the configuration to be imparted to the glass sheets, a continuous shaping surface complementary to said configuration opposite said shaping rail, means for advancing a heated sheet from an adjacent furnace into press bending position between said shaping rail and continuous shaping surface, and means for moving said shaping rail and said continuous shaping surface toward and away from one another for press bending said heated sheet between said shaping surface and said opposed continuous shaping surface to said predetermined configuration, the improvement comprising heating means disposed along and in contact with said shaping rail opposite said shaping surface to provide heat to at least a portion of said shaping rail for supplying heat to said portion for reducing heat transfer from said heated sheet to said shaping rail during press bending, said heating means comprising a plurality of individual elongated electrical resistance heating element segments disposed beneath and substantially entirely around said ring-type shaping rail, and means individually connecting each said resistance heating element to a controllable source of electrical energy, said shaping rail and said heating elements disposed therebeneath being supported upon a base plate by a plurality of connecting rods positioned at spaced locations around said shaping rail, each said connecting rod having a bifurcated connecting yoke at its end adjacent said shaping rail, a spaced pair of connecting plates affixed to said shaping rail at each said connecting rod for receiving said connecting yoke therebetween, and pin means extending through said connecting plates and yoke for affixing said shaping rail to said connecting rod.
Dependencies are inferred from the claim text.