Granted Patent
Utility
US 4,255,175 · App. 06/084,462
Gas separation filter device having a handle
Inventor:
O. DuWayne Wilkins
Patented Case
View Patent ↗
Granted: Mar 10, 1981
Filed: Oct 12, 1979
Inventor
O. DuWayne Wilkins
Assignee (at issue)
AMERICAN AIR FILTER COMPANY, INC.
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.