Granted Patent
Utility
US 4,267,807 · App. 06/055,215
Internal combustion engines
Inventor:
Herbert Edward Ashfield
Patented Case
View Patent ↗
Granted: May 19, 1981
Filed: Jul 6, 1979
Inventor
Herbert Edward Ashfield
Assignee (at issue)
David Brown Tractors Ltd.
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.