Granted Patent
Utility
US 4,788,747 · App. 06/946,203
Counterbalance apparatus with transverse pneumatic spring and bellcrank linkage
Inventor:
George C. Ludwig
Patented Case
View Patent ↗
Granted: Dec 6, 1988
Filed: Dec 19, 1986
Inventor
George C. Ludwig
Assignee (at issue)
AVM, Inc.
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.