Granted Patent
Utility
US 4,656,339 · App. 06/674,698
Electrical resistance heater
Inventor:
Frederick G. J. Grise
Patented Case
View Patent ↗
Granted: Apr 7, 1987
Filed: Nov 26, 1984
Inventor
Frederick G. J. Grise
Assignee (at issue)
Flexwatt 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.