Granted Patent
Utility
US 4,121,705 · App. 05/820,175
Wear ring for spring of friction coupling
Inventor:
Richard L. Hedgcock
Patented Case
View Patent ↗
Granted: Oct 24, 1978
Filed: Jul 29, 1977
Inventor
Richard L. Hedgcock
Assignee (at issue)
Caterpillar Tractor Co.
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.