Granted Patent
Utility
US 6,056,005 · App. 08/968,609
Vent valve with liquid seal
Inventors:
Thomas C. Piotrowski, Martin Clift, Baohai Liu
Patented Case
View Patent ↗
Granted: May 2, 2000
Filed: Nov 13, 1997
Inventors
Thomas C. Piotrowski
Martin Clift
Baohai Liu
Assignee (at issue)
THE PROTECTOSEAL 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.