Granted Patent
Utility
US 4,636,161 · App. 06/721,896
Screen for selectively perforating thermoplastic film
Inventors:
Garland E. Raley, Dean M. Spear
Patented Case
View Patent ↗
Granted: Jan 13, 1987
Filed: Apr 11, 1985
Inventors
Garland E. Raley
Dean M. Spear
Assignee (at issue)
Ethyl 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.