Granted Patent
Utility
US 4,359,889 · App. 06/133,010
Self-centering seal for use in hydraulically expanding tubes
Inventor:
John W. Kelly
Patented Case
View Patent ↗
Granted: Nov 23, 1982
Filed: Mar 24, 1980
Inventor
John W. Kelly
Assignee (at issue)
Haskel Engineering & Supply 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.