Granted Patent
Utility
US 5,701,931 · App. 08/550,245
Water relief valve for a drainage system
Inventors:
Trevor Phillips, James E. Petrie
Patented Case
View Patent ↗
Granted: Dec 30, 1997
Filed: Oct 30, 1995
Inventors
Trevor Phillips
James E. Petrie
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.