Granted Patent
Utility
US 4,290,236 · App. 06/089,117
Method and apparatus for manufacturing a contoured internal diameter bushing
Inventors:
Thomas D. Brewer, Robert J. Purcell, James R. Sturges
Patented Case
View Patent ↗
Granted: Sep 22, 1981
Filed: May 14, 1979
Inventors
Thomas D. Brewer
Robert J. Purcell
James R. Sturges
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.