Granted Patent
Utility
US 4,532,835 · App. 06/607,540
Bi-directional filter wrench
Inventor:
Brian M. Schwitters
Patented Case
View Patent ↗
Granted: Aug 6, 1985
Filed: May 7, 1984
Inventor
Brian M. Schwitters
Assignee (at issue)
Parker-Hannifin 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.