Granted Patent
Utility
US 4,858,731 · App. 07/218,867
Composite brake drum
Inventor:
John W. Bush
Patented Case
View Patent ↗
Granted: Aug 22, 1989
Filed: Jul 14, 1988
Inventor
John W. Bush
Assignee (at issue)
The Budd Company
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.