Apparatus for supporting shaped glass sheets for tempering

Abstract

An outline ring-like tempering mold for supporting shaped glass sheets after they are shaped and during the time they are rapidly quenched, comprising a rigid outline metal rail having an outline slightly inward that of the shaped glass sheet and a bar of non-metallic material having a lower heat transfer coefficient than that of the rigid metal rail and mounted on the rigid metal rail in position to conform to the outline and with an upper edge portion of the bar disposed above the upper edge of the rigid metal rail in position to provide a glass sheet supporting surface in spaced relation above the upper edge of the rigid metal rail. The bar is preferably composed of a material having a heat transfer coefficient less than or, at most, approximating that of the glass sheet being treated, an edgewise compressive strength of at least 10,000 psi (4.8 .times. 10.sup.4 Kg/m.sup.2), a flexural strength of 10,000 psi (4.8 .times. 10.sup.4 Kg/m.sup.2) and a minimum shear strength of 10,000 psi (4.8 .times. 10.sup.4 Kg/m.sup.2). When the bar is composed of a laminated structure, such as fiber glass cloth or asbestos woven paper layers or the like bonded together with a silicone resin binder or a phenolic resin binder, for example, the bar preferably has a bond strength of at least 400 pounds (180 Kg). The bar material effectively insulates a supported glass sheet from direct contact with the rigid metal rail and is sufficiently reinforced by said metal rail to provide adequate support for a shaped glass sheet when the latter is quenched.

Dependencies are inferred from the claim text.