Granted Patent
Utility
US 4,320,691 · App. 06/143,996
Hydraulic load lifting system with hydraulic surcharge to make up valve pilot lines
Inventor:
Orcenith D. McWilliams
Patented Case
View Patent ↗
Granted: Mar 23, 1982
Filed: Nov 16, 1979
Inventor
Orcenith D. McWilliams
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.