Granted Patent
Utility
US 4,552,335 · App. 06/548,320
Ball valve
Inventors:
William H. Alexander, Roy R. Dare
Patented Case
View Patent ↗
Granted: Nov 12, 1985
Filed: Nov 3, 1983
Inventors
William H. Alexander
Roy R. Dare
Assignee (at issue)
VAPOR CORP.
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.