Granted Patent
Utility
US 4,646,840 · App. 06/729,623
Flotation riser
Inventors:
Roy E. Bartholomew, Ronald G. Pettus, Emanuel Schnitzer, Edmund A. Fisher
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: May 2, 1985
Inventors
Roy E. Bartholomew
Ronald G. Pettus
Emanuel Schnitzer
Edmund A. Fisher
Assignee (at issue)
Cameron Iron Works, Inc.
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.