Granted Patent
Utility
US 4,249,567 · App. 05/081,132
Check-valve construction
Inventor:
Paul D. Weiss
Patented Case
View Patent ↗
Granted: Feb 10, 1981
Filed: Oct 2, 1979
Inventor
Paul D. Weiss
Assignee (at issue)
Transamerica DeLaval 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.