Granted Patent
Utility
US 5,491,746 · App. 08/207,958
Unique ringing on a prime telephone
Inventor:
Deborah L. Pinard
Patented Case
View Patent ↗
Granted: Feb 13, 1996
Filed: Mar 8, 1994
Inventor
Deborah L. Pinard
Assignee (at issue)
Mitel 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.