Granted Patent
Utility
US 5,185,969 · App. 07/811,816
Positive retracting honing mandrel
Inventor:
Frank E. Vanderwal, Jr.
Patented Case
View Patent ↗
Granted: Feb 16, 1993
Filed: Dec 20, 1991
Inventor
Frank E. Vanderwal, Jr.
Assignee (at issue)
Sunnen Products Company
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.