Ppg Industries, Inc.

Terry A Bennett

William B Zimmerman

Michael T Fecik

John J Ewing

Robert G Frank

George R Claassen

Thomas J Reese

DeWitt W Lampman

Barry L Shadle

Herbert W Eilenfeld

Michael B Maslanka

James E Carino

A vacuum press construction having holes on the press face corresponding to aperture in the glass sheet to be shaped. The holes are sealed in a manner so as to minimize the amount of heat drawn from the periphery of the glass sheet apertures during the pressing operation and maintain glass edge strength at the aperture.

Vacuum press construction

A pair of heat softened overlaying glass sheets are held by vacuum against an apertured engaging surface of a vacuum holder. The overlaying glass sheets can be shaped before, during, or after being held by the vacuum holder.

Vacuum pressing of glass doublets

A hot glass sheet shaping apparatus for shaping glass sheets with selected portions wider than its trailing edge as it is conveyed to the shaping station. Flotation blocks are positioned adjacent a gas hearth bed support in the shaping station to support the selected portions of the glass sheet as they are conveyed thereover, to prevent these portions from contacting the gas hearth bed.

Method and apparatus for shaping glass sheets on shaping molds with

Apparatus for handling hot glass sheets comprises a rigid ring-like member of a composition that causes rejectable defects in a bent glass sheet when it contacts the hot glass sheet directly. Insulating material that does not mar the glass sufficiently to cause rejectable defects is used to cover the rigid member. However, no material known to date lasts forever. The present invention provides screen mesh reinforcement means within the thickness of the glass sheet engaging member to produce fine marks that do not cause rejection of the finished article to warn operating personnel to replace the hot glass sheet engaging member with a fresh hot glass sheet engaging member before the hot glass sheet engaging member becomes worn to the extent that the rigid member causes a rejectable defect. Clamping means is provided to replace a worn glass engaging member rapidly. Optionally, a cushion of fibrous ceramic material is interposed between the rigid member and the hot glass sheet engaging member to enable the glass engaging surface of the hot glass sheet engaging member to conform to the downwardly facing shaping surface of an upper vacuum mold.

Apparatus for press shaping hot glass sheets

Glass edge engagement members for use with an outline bending mold having mold portions with upwardly facing shaping surfaces are spring biased to enable the glass edge engaging members to move between an extended position above the shaping surface due to spring biasing force and a retracted position due to abutment force that opposes the spring biasing force when said outline bending mold abuts another shaping mold.

Spring loaded stop member for glass sheet shaping molds

The invention involves a method and apparatus for bending glass sheets to an S-shaped transverse bend with a longitudinal bend. The heat softened glass sheets are serially conveyed onto a gas hearth bed having a downwardly curved end portion at the downstream end thereof such that the glass sheet curves into conformation with the gas hearth, then by means of a curved outline mold lifting the glass sheet vertically into conformation with an overlying vacuum mold, holding the shaped sheet into contact with the vacuum mold by vacuum while lowering the outline mold, then moving a shuttle ring beneath the glass sheet, discontinuing the vacuum such that the glass sheet is deposited onto the shuttle ring and then moving the shuttle ring and glass sheet laterally for further processing.

Method and apparatus for bending glass sheets to complicated shapes

In tempering a glass sheet to a high temper by heating the sheet to approximately its softening point followed by rapid chilling using a quenching composition that comprises a tempering medium having high heat transfer characterisitcs, the heat-softened glass sheets are protected from breakage during fabrication and resulting optical distortion by applying the tempering medium through exit orifices of a delivery system toward the heated glass in a novel cycle. The initially applied tempering medium has a low heat transfer rate and is mixed with a second tempering medium having a higher heat transfer rate to gradually increase the heat transfer rate of the mixed tempering medium. In a specific embodiment, dry air is the first tempering medium and a sublimable material, such as carbon dioxide, is the second tempering medium. The delivery system has an uninsulated portion that assures that initially the sublimable material is applied as a gas. Dry air which has a lesser heat transfer coefficient than the sublimable material in its gaseous state, may be supplied to the uninsulated portion if humidity conditions require so that dry air having a lesser heat transfer coefficient is initially directed through the exit orifices followed by mixtures of dry air with increasing concentrations of said sublimable material in the gaseous state followed by increasing concentrations of solid particles of said sublimable material. Movement of the glass sheet is coordinated with movement of the delivery system for said quenching composition to avoid 'batter'.

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Verona, PA, United States of America

Terry A Bennett