Granted Patent
Utility
US 4,052,852 · App. 05/744,073
Constant pressure sealed fluid storage tank for hydraulic systems
Inventor:
Cullen P. Hart
Patented Case
View Patent ↗
Granted: Oct 11, 1977
Filed: Nov 22, 1976
Inventor
Cullen P. Hart
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.