Granted Patent
Utility
US 4,333,728 · App. 06/070,877
Compound hub spring system for helicopters
Inventors:
Jan M. Drees, Larry W. Dooley, William D. Neathery
Patented Case
View Patent ↗
Granted: Jun 8, 1982
Filed: Aug 29, 1979
Inventors
Jan M. Drees
Larry W. Dooley
William D. Neathery
Assignee (at issue)
Textron 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.