Ppg Industries, Inc.

David B Rayburn

George R Claassen

Thomas J Reese

Rudolph A Karlo

Irvin A Wilson

Jeffrey L Marietti

John L McLaughlin

William P Cathers

The present invention discloses a method and apparatus for shaping glass sheets to deeply sagged configurations using a lower outline mold and an upper shaping mold while minimizing marking of the sheets by shaping molds. The outline mold includes a support rail which generally corresponds to the desired curvature of a peripheral portion of the sheets to be shaped and supports the glass sheets as they are heated and sagged by gravity to a preliminary shape. The outline mold and the upper mold are then moved relative to each other to position the molds either in close proximity to each other or to press the upper mold against the glass sheets. Pressurized gas is then directed from the mold to at least the unsupported central portions of the preliminarily shaped sheets, to urge these unsupported portions downward and shape the sheets to a desired configuration.

Pressure forming of glass sheets

The present invention discloses a method for shaping glass sheets to deeply sagged configurations using a lower outline mold and an upper shaping mold while minimizing marking of the sheets by shaping molds. The outline mold includes a support rail which generally corresponding to the desired curvature of a peripheral portion of the sheets to be shaped and supports the glass sheets as they are heated and sagged by gravity to a preliminary shape. The outline mold and the upper mold are then moved relative to each other to position the molds either in close proximity to each other or to press the upper mold against the glass sheets. Pressurized gas is then directed from the mold to at least the unsupported central portions of the preliminarily shaped sheets, to urge these unsupported portions downward and shape the sheets to a desired configuration.

A method of reducing localized tensile stresses in shaped glass sheets formed by sag bending. An unperforated thermal insulating member is mounted throughout the area within a shaping rail and spaced below a heat softened glass sheet shaped on the shaping rail to thermally insulate the glass from heat reradiated from the shaping rail and reduce air circulation beneath the sheet so as to support structure during the cooling of the shaped glass sheet and provide more uniform cooling of the entire glass sheet.

Glass shaping ring having a thermal insulating member and method of

A method and apparatus for reducing tip curl caused by sag bending complicated shapes in glass sheets. A pivoting assembly with a glass edge roller contacts the edge of the glass sheet as it is conveyed through a heating lehr or a bending mold, and biases the glass against the bending rail.

Growing community of inventors

Vandergrift, PA, United States of America

David B Rayburn