Granted Patent
Utility
US 4,986,576 · App. 07/509,201
Locking door latch
Inventor:
John P. Anderson
Patented Case
View Patent ↗
Granted: Jan 22, 1991
Filed: Apr 16, 1990
Inventor
John P. Anderson
Assignee (at issue)
Hartwell 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.