Granted Patent
Utility
US 5,152,032 · App. 07/704,804
Window sash balance with tension and torsion spring
Inventors:
Donald D. Davis, William P. Newton, Norman R. Westfall
Patented Case
View Patent ↗
Granted: Oct 6, 1992
Filed: May 23, 1991
Inventors
Donald D. Davis
William P. Newton
Norman R. Westfall
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.