Granted Patent
Utility
US 4,907,829 · App. 07/141,292
Pipe joint assembly
Inventor:
Melvin Spangenberg
Patented Case
View Patent ↗
Granted: Mar 13, 1990
Filed: Jan 5, 1988
Inventor
Melvin Spangenberg
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.