Granted Patent
Utility
US 4,478,237 · App. 06/512,259
Pressure modulating and reducing valve
Inventors:
William W. Blake, Alan R. Coutant
Patented Case
View Patent ↗
Granted: Oct 23, 1984
Filed: Jul 11, 1983
Inventors
William W. Blake
Alan R. Coutant
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.