Granted Patent
Utility
US 4,542,285 · App. 06/646,688
Electrical heater
Inventor:
Frederick G. J. Grise
Patented Case
View Patent ↗
Granted: Sep 17, 1985
Filed: Aug 31, 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.