Granted Patent
Utility
US 4,227,646 · App. 05/964,934
Temperature-responsive valve
Inventors:
William B. Hart, Reginald Williams
Patented Case
View Patent ↗
Granted: Oct 14, 1980
Filed: Nov 30, 1978
Inventors
William B. Hart
Reginald Williams
Assignee (at issue)
Delta Materials Research 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.