Granted Patent
Utility
US 4,543,299 · App. 06/534,359
Laminated, seamless, cylindrical metal screen for vacuum perforation of thermoplastic film
Inventors:
Garland E. Raley, Dean M. Spear
Patented Case
View Patent ↗
Granted: Sep 24, 1985
Filed: Sep 21, 1983
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.