Granted Patent
Utility
US 5,267,416 · App. 07/914,256
Window sash counterbalance with varying lift
Inventor:
Donald D. Davis
Patented Case
View Patent ↗
Granted: Dec 7, 1993
Filed: Jul 15, 1992
Inventor
Donald D. Davis
Assignee (at issue)
CALDWELL MANUFACTURING COMPANY
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.