Granted Patent
Utility
US 4,993,521 · App. 07/395,376
Tread brake unit
Inventors:
Yoshio Asano, Takeshi Kishimoto, Mitugu Tunazawa
Patented Case
View Patent ↗
Granted: Feb 19, 1991
Filed: Aug 17, 1989
Inventors
Yoshio Asano
Takeshi Kishimoto
Mitugu Tunazawa
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.