Granted Patent
Utility
US 5,636,678 · App. 08/435,586
Counterbalancing mechanism for an overhead door
Inventors:
Kenneth E. Carper, Alan R. Leist
Patented Case
View Patent ↗
Granted: Jun 10, 1997
Filed: May 5, 1995
Inventors
Kenneth E. Carper
Alan R. Leist
Assignee (at issue)
Clopay Building Products Company, Inc.
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.