Granted Patent
Utility
US 4,263,536 · App. 05/931,668
Control circuit for a motor-driven door operator
Inventors:
Maw H. Lee, Chun-Fu Chen
Patented Case
View Patent ↗
Granted: Apr 21, 1981
Filed: Aug 7, 1978
Inventors
Maw H. Lee
Chun-Fu Chen
Assignee (at issue)
Clopay Corporation
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.