Granted Patent
Utility
US 4,919,456 · App. 07/335,893
Union for pipe or tree with metal and resilient seals
Inventor:
Kwok-Ping Wong
Patented Case
View Patent ↗
Granted: Apr 24, 1990
Filed: Apr 10, 1989
Inventor
Kwok-Ping Wong
Assignee (at issue)
Otis Engineering 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.