Granted Patent
Utility
US 6,158,643 · App. 09/001,454
Internal combustion fastener driving tool piston and piston ring
Inventor:
Alan Phillips
Patented Case
View Patent ↗
Granted: Dec 12, 2000
Filed: Dec 31, 1997
Inventor
Alan Phillips
Assignee (at issue)
Porter-Cable Corporation
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.