Granted Patent
Utility
US 4,682,939 · App. 06/843,675
Gear pump or motor with tooth tips of dissimilar metal
Inventor:
John D. Petro
Patented Case
View Patent ↗
Granted: Jul 28, 1987
Filed: Mar 25, 1986
Inventor
John D. Petro
Assignee (at issue)
Commercial Shearing, 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.