Granted Patent
Utility
US 4,844,183 · App. 07/114,560
Accelerator for fishing jar with hydrostatic assist
Inventor:
Robert W. Evans
Patented Case
View Patent ↗
Granted: Jul 4, 1989
Filed: Oct 28, 1987
Inventor
Robert W. Evans
Assignee (at issue)
Dailey Petroleum Services Corp.
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.