Granted Patent
Utility
US 4,763,736 · App. 07/071,157
Asymmetrical rotary cone bit
Inventor:
Daniel W. Varel
Patented Case
View Patent ↗
Granted: Aug 16, 1988
Filed: Jul 8, 1987
Inventor
Daniel W. Varel
Assignee (at issue)
Varel Manufacturing 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.