Granted Patent
Utility
US 4,731,056 · App. 06/935,105
External drainage antisiphon device
Inventor:
William S. Tremulis
Patented Case
View Patent ↗
Granted: Mar 15, 1988
Filed: Nov 24, 1986
Inventor
William S. Tremulis
Assignee (at issue)
CORDIS 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.