Granted Patent
Utility
US 4,653,521 · App. 06/882,728
Freezeless ground hydrant and method for operating same
Inventor:
Russell L. Fillman
Patented Case
View Patent ↗
Granted: Mar 31, 1987
Filed: Jul 7, 1986
Inventor
Russell L. Fillman
Assignee (at issue)
Woodford Manufacturing Company
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.