Granted Patent
Utility
US 4,719,937 · App. 06/802,997
Marine riser anti-collapse valve
Inventors:
Joseph R. Roche, Gabriel G. Alexander
Patented Case
View Patent ↗
Granted: Jan 19, 1988
Filed: Nov 29, 1985
Inventors
Joseph R. Roche
Gabriel G. Alexander
Assignee (at issue)
Hydril 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.