Granted Patent
Utility
US 4,466,631 · App. 06/424,006
Ball joint assembly for draft arm
Inventor:
David A. Berg
Patented Case
View Patent ↗
Granted: Aug 21, 1984
Filed: Sep 27, 1982
Inventor
David A. Berg
Assignee (at issue)
Allis-Chalmers 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.