Granted Patent
Utility
US 4,252,209 · App. 06/004,167
Downhole liquid pressure seismic source and bit positioning system
Inventor:
Daniel Silverman
Patented Case
View Patent ↗
Granted: Feb 24, 1981
Filed: Jan 17, 1979
Inventor
Daniel Silverman
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.