Granted Patent
Utility
US 5,310,005 · App. 07/900,665
Flapper valve assembly with floating hinge
Inventor:
William W. Dollison
Patented Case
View Patent ↗
Granted: May 10, 1994
Filed: Jun 19, 1992
Inventor
William W. Dollison
Assignee (at issue)
Halliburton
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.