Granted Patent
Utility
US 4,817,213 · App. 07/157,887
Method for forming a torus and a piston made therefrom for use in a rotary actuator
Inventor:
William B. Scobie
Patented Case
View Patent ↗
Granted: Apr 4, 1989
Filed: Feb 19, 1988
Inventor
William B. Scobie
Assignee (at issue)
Keystone International
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.