Granted Patent
Utility
US 4,673,848 · App. 06/804,833
Control system for an automatic door
Inventors:
Isao Hagiwara, Yukio Yoshida
Patented Case
View Patent ↗
Granted: Jun 16, 1987
Filed: Dec 5, 1985
Inventors
Isao Hagiwara
Yukio Yoshida
Assignee (at issue)
Yoshida Kogyo K.K.
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.