Thomas W Hawk

US Patent:

44459530, May 1, 1984

Filed:

Feb 25, 1982

Appl. No.:

6/352423

Inventors:

Thomas W. Hawk - New Kensington PA

Assignee:

PPG Industries, Inc. - Pittsburgh PA

International Classification:

B32B 1700
B32B 3100
B29C 1704
C03B 2100

US Classification:

156102

Abstract:

Lightweight aircraft transparencies are shaped to a desired configuration by laying up a plurality of flat oversized plastic sheets in a desired sequence to form a flat assembly. Portions of the marginal edges of the flat assembly are supported on a female support ring having a non-planar supporting surface. The assembly is first shaped at a temperature below its deformation temperature to a preliminary shape where its marginal edge portions conform to the non-planar supporting surface of the female support ring. While the marginal edges of the preliminarily shaped assembly are maintained in conformity with the female support ring, the assembly is uniformly exposed in an enclosed autoclave to elevated pressures to minimize outgassing and to elevated temperatures above its deformation temperature. A male form having an outline smaller than the female support ring engages the central portion of the preliminarily shaped assembly to impress the desired final shape thereto, e. g. , a compound configuration.

US Patent:

41742419, Nov 13, 1979

Filed:

Jul 21, 1978

Appl. No.:

5/926685

Inventors:

Paul A. Rockar - Cabot PA
Melvin K. Law - New Kensington PA
Thomas W. Hawk - New Kensington PA

Assignee:

PPG Industries, Inc. - Pittsburgh PA

International Classification:

B32B 3120

US Classification:

156102

Abstract:

The present invention relates to simultaneous press polishing and lamination of laminated plastic transparencies such as are used in aircraft as aircraft windshields or aircraft canopies. The present invention is especially useful to minimize deviations from surface smoothness of the all plastic laminates due to the entrapment of air that form air pockets within a flexible evacuating bag within which an assembly to be press polished and laminated is inserted during its fabrication.