Granted Patent
Utility
US 6,442,897 · App. 09/626,661
Counterbalance system cable drum for sectional doors
Inventor:
Willis Jay Mullet
Patented Case
View Patent ↗
Granted: Sep 3, 2002
Filed: Jul 27, 2000
Inventor
Willis Jay Mullet
Assignee (at issue)
Wayne-Dalton 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.