Granted Patent
Utility
US 4,769,009 · App. 06/917,789
Apparatus for displacing a piston in a chamber having a torque resistor
Inventor:
Raymond C. Dykstra
Patented Case
View Patent ↗
Granted: Sep 6, 1988
Filed: Oct 10, 1986
Inventor
Raymond C. Dykstra
Assignee (at issue)
Cobe Laboratories, Inc.
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.