Granted Patent
Utility
US 4,309,040 · App. 06/155,949
Linear seal apparatus
Inventor:
Michel A. Pierrat
Patented Case
View Patent ↗
Granted: Jan 5, 1982
Filed: Jun 3, 1980
Inventor
Michel A. Pierrat
Assignee (at issue)
Ferrofluidics Corporation
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.