Granted Patent
Utility
US 4,238,020 · App. 05/858,864
Centrifugal clutch with an overspeed relief valve and clutch modulation
Inventors:
Karl A. Nerstad, Curtis E. Chadwick, III, Gordon W. Johnson
Patented Case
View Patent ↗
Granted: Dec 9, 1980
Filed: Dec 8, 1977
Inventors
Karl A. Nerstad
Curtis E. Chadwick, III
Gordon W. Johnson
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.