Granted Patent
Utility
US 4,222,147 · App. 05/888,217
Door closer with assist or door operating features
Inventor:
L. Nelson Burnett, Jr.
Patented Case
View Patent ↗
Granted: Sep 16, 1980
Filed: Mar 20, 1978
Inventor
L. Nelson Burnett, Jr.
Assignee (at issue)
Reading Door Closer Corp.
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.