Granted Patent
Utility
US 4,644,717 · App. 06/709,573
Curtain wall valve system
Inventor:
Lawrence F. Biebuyck
Patented Case
View Patent ↗
Granted: Feb 24, 1987
Filed: Mar 8, 1985
Inventor
Lawrence F. Biebuyck
Assignee (at issue)
BUTLER MANUFACTURING COMPANY
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.