Granted Patent
Utility
US 4,624,310 · App. 06/736,232
Well apparatus
Inventors:
Ralph H. Echols, Bhanubhai H. Patel, James B. Renfroe, Jr.
Patented Case
View Patent ↗
Granted: Nov 25, 1986
Filed: May 20, 1985
Inventors
Ralph H. Echols
Bhanubhai H. Patel
James B. Renfroe, Jr.
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.