Granted Patent
Utility
US 4,541,455 · App. 06/559,636
Automatic vent valve
Inventor:
Hugo Hauser
Patented Case
View Patent ↗
Granted: Sep 17, 1985
Filed: Dec 12, 1983
Inventor
Hugo Hauser
Assignee (at issue)
Tri-Tec Industries Ltd.
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.