Granted Patent
Utility
US 4,926,906 · App. 07/303,656
Spool valve
Inventors:
Kouji Ichihashi, Junichi Tani, Katsuhiko Tsukazaki, Hiroshi Sakuyama, Nobuo Baba, Kiyoji Nakajima, Takaaki Arai, Akira Inaba
Patented Case
View Patent ↗
Granted: May 22, 1990
Filed: Jan 30, 1989
Inventors
Kouji Ichihashi
Junichi Tani
Katsuhiko Tsukazaki
Hiroshi Sakuyama
Nobuo Baba
Kiyoji Nakajima
Takaaki Arai
Akira Inaba
Assignee (at issue)
Diesel Kiki 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.