Granted Patent
Utility
US 4,376,597 · App. 06/240,563
Pull-out diaphragm seal for hollow tubes
Inventors:
Frederick G. Britton, William G. Stanfield, Don B. Landers
Patented Case
View Patent ↗
Granted: Mar 15, 1983
Filed: Mar 4, 1981
Inventors
Frederick G. Britton
William G. Stanfield
Don B. Landers
Assignee (at issue)
OIL STATES 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.