Granted Patent
Utility
US 4,780,122 · App. 07/067,036
Vacuum refining of glass or the like with enhanced foaming
Inventors:
Ronald L. Schwenninger, Wright M. Welton, Boyd S. Dawson, Joseph M. Matesa, Larry J. Shelestak
Patented Case
View Patent ↗
Granted: Oct 25, 1988
Filed: Jun 29, 1987
Inventors
Ronald L. Schwenninger
Wright M. Welton
Boyd S. Dawson
Joseph M. Matesa
Larry J. Shelestak
Assignee (at issue)
PPG Industries, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.