Granted Patent
Utility
US 4,917,148 · App. 07/278,387
Load dependent valve for railway vehicles
Inventor:
Hideo Tamamori
Patented Case
View Patent ↗
Granted: Apr 17, 1990
Filed: Dec 1, 1988
Inventor
Hideo Tamamori
Assignee (at issue)
Nippon Air Brake 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.