Granted Patent
Utility
US 4,477,611 · App. 06/530,163
Reinforced rubber composition containing ground coal
Inventor:
Richard J. Sperley
Patented Case
View Patent ↗
Granted: Oct 16, 1984
Filed: Sep 7, 1983
Inventor
Richard J. Sperley
Assignee (at issue)
Uniroyal 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.