Granted Patent
Utility
US 4,614,475 · App. 06/737,884
Hydraulic circuit system for civil engineering and architectural machinery
Inventors:
Seiji Tamura, Toshimichi Ikeda, Toichi Hirata
Patented Case
View Patent ↗
Granted: Sep 30, 1986
Filed: May 28, 1985
Inventors
Seiji Tamura
Toshimichi Ikeda
Toichi Hirata
Assignee (at issue)
HITACHI CONSTRUCTION MACHINERY CO., LTD.
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.