Ppg Industries, Inc.

Melvin W Tobin

Thomas J Reese

James R Mortimer

Stephen J Jursa

W Robert Gray, Jr

A method of fabricating bent laminated safety glass windshields having at least one hole through the entire thickness thereof adjacent to but spaced entirely from the marginal edge thereof is disclosed.

Method of making bent laminated glass windshields with drilled apertures

Glass sheets are bent along a line which is sharply creased at one end and gently curved at the opposite end. Localized heating along the line is provided by an electrically heated ribbon mounted above the glass so as to maintain a constant spacing between the glass and the ribbon at one end of the line, while the spacing at the other end of the line gradually increases as bending progresses.

Bending glass sheets to a tapered line of bend

This invention relates to a method and apparatus for bending glass sheets in pairs to a so-called double V-bend in which the glass is bent sharply across its width along two lines of sharp bending to form a pair of sharply bent longitudinal extremity portions. The gist of the invention is the application to a sectionalized mold of weighted elongated electroconductive ribbons which are unattached to any mold structure and each of which is readily applied to and removed from positions above the upper surface of the glass sheets mounted on the mold for bending in sliding superimposed relation to a pair of electrodes along lines aligned with the lines of sharp bending. The ribbons are maintained in spaced relation to the glass throughout the bending operation so as to avoid marking the glass. The mold sections terminate at locations along transverse lines aligned with and slightly below the ribbons.

Method and apparatus for bending glass sheets to double V-bends

Shaping glass sheets of soda-lime-silica compositions by gravity sagging into complicated shapes having a portion of convex curvature and another portion of concave curvature requires a continuous shaping surface onto which a supported glass sheet is heated and sags. The present invention provides a method of bending soda-lime-silica glass sheets onto curved molds of a complicated curvature comprising a previously shaped sheet of a glassy composition having a heat capacity approximating that of the soda-lime-silica composition and a lower coefficient of thermal expansion and a higher deformation temperature than those of the sode-lime-silica composition of the glass sheet to be bent. The layer of glassy composition which provides the mold shaping surface is in turn supported on a metal frame of outline configuration conforming in elevation and outline to the shape of the layer of the special glassy composition, and preferably has a minimum thickness at least equal to the glass sheet to be shaped to insure that when the composite mold comprising the shaped outline metal frame and the superimposed shaped layer supporting a glass sheet to be shaped is heated to the deformation temperature of the glass sheet, the layer retains its shape sufficiently to be used as part of the composite mold in subsequent bending operations. A layer of knit fiber glass composition is held in stretched relation over the upper shaping surface of the layer of special glassy composition to reduce the possibility of surface damage to the shaped glass sheet. Glass sheets shaped on such composite molds by gravity sagging conform closely to the desired complicated shape and also have a desired stress pattern in the marginal edge portion.

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New Kensington, PA, United States of America

Melvin W Tobin