Granted Patent
Utility
US 4,877,093 · App. 07/163,583
Spring actuated power swivel support rollers
Inventors:
David B. Ford, James E. Lynch, Leroy R. Rateike
Patented Case
View Patent ↗
Granted: Oct 31, 1989
Filed: Mar 3, 1988
Inventors
David B. Ford
James E. Lynch
Leroy R. Rateike
Assignee (at issue)
National Oilwell, 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.