Granted Patent
Utility
US 4,451,004 · App. 06/032,203
Flail head
Inventors:
William F. Ostergren, Albert J. Ipnar
Patented Case
View Patent ↗
Granted: May 29, 1984
Filed: Apr 23, 1979
Inventors
William F. Ostergren
Albert J. Ipnar
Assignee (at issue)
Sperry Corp.
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.