Granted Patent
Utility
US 4,286,432 · App. 06/093,072
Lock valve with variable length piston and hydraulic system for a work implement using the same
Inventors:
J. W. Burrows, Loyal O. Watts
Patented Case
View Patent ↗
Granted: Sep 1, 1981
Filed: Aug 30, 1979
Inventors
J. W. Burrows
Loyal O. Watts
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.