Granted Patent
Utility
US 4,250,794 · App. 05/892,370
High pressure hydraulic system
Inventors:
Willard J. Haak, Howard A. Marsden, James P. Mueller
Patented Case
View Patent ↗
Granted: Feb 17, 1981
Filed: Mar 31, 1978
Inventors
Willard J. Haak
Howard A. Marsden
James P. Mueller
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.