Granted Patent
Utility
US 4,809,128 · App. 07/065,360
Heating element operating unit and method
Inventor:
Frederick J. Geary
Patented Case
View Patent ↗
Granted: Feb 28, 1989
Filed: Jun 23, 1987
Inventor
Frederick J. Geary
Assignee (at issue)
ROBERTSHAW CONTROLS PRIVATE LIMITED
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.