Granted Patent
Utility
US 4,981,546 · App. 07/405,590
Heat-sealing device for thermoplastic films
Inventor:
Kevin Bergevin
Patented Case
View Patent ↗
Granted: Jan 1, 1991
Filed: Sep 8, 1989
Inventor
Kevin Bergevin
Assignee (at issue)
Kevin Bergevin
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.