Granted Patent
Utility
US 4,512,405 · App. 06/584,581
Pneumatic transfer of solids into wells
Inventors:
Ronald E. Sweatman, Earl R. Freeman, John Gottschling, John B. Simon
Patented Case
View Patent ↗
Granted: Apr 23, 1985
Filed: Feb 29, 1984
Inventors
Ronald E. Sweatman
Earl R. Freeman
John Gottschling
John B. Simon
Assignee (at issue)
Hughes Tool Company LLC
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.