Granted Patent
Utility
US 4,830,580 · App. 07/128,768
Two-stage air compressor unit
Inventors:
Yasuhisa Hata, Satoshi Ogura
Patented Case
View Patent ↗
Granted: May 16, 1989
Filed: Dec 4, 1987
Inventors
Yasuhisa Hata
Satoshi Ogura
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.