Granted Patent
Utility
US 6,655,697 · App. 10/051,799
Piston oil ring having land flanked by concave sidewalls
Inventors:
Stephane Heraud, William E. Spengler
Patented Case
View Patent ↗
Granted: Dec 2, 2003
Filed: Jan 18, 2002
Inventors
Stephane Heraud
William E. Spengler
Assignee (at issue)
DANA LIMITED
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.