Granted Patent
Utility
US 4,976,320 · App. 07/356,740
Concealed sprinkler with drop down deflector assembly, and improved fusible valve lever assembly
Inventor:
George S. Polan
Patented Case
View Patent ↗
Granted: Dec 11, 1990
Filed: May 25, 1989
Inventor
George S. Polan
Assignee (at issue)
CENTRAL SPRINKLER 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.