Granted Patent
Utility
US 4,425,972 · App. 06/291,393
Split ring spring for earth working tool
Inventor:
Richard W. Steinberg
Patented Case
View Patent ↗
Granted: Jan 17, 1984
Filed: Aug 10, 1981
Inventor
Richard W. Steinberg
Assignee (at issue)
Hiniker 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.