Granted Patent
Utility
US 4,646,853 · App. 06/636,381
Shaft boring machine and method
Inventors:
David B. Sugden, David T. Cass, Peter B. Dowden, Nicholas A. Hynd
Patented Case
View Patent ↗
Granted: Mar 3, 1987
Filed: Jul 31, 1984
Inventors
David B. Sugden
David T. Cass
Peter B. Dowden
Nicholas A. Hynd
Assignee (at issue)
Robbins, 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.