Granted Patent
Utility
US 4,688,764 · App. 06/707,969
Crown block compensator
Inventors:
Douglas W. J. Nayler, Fred R. Foreman, Willard D. Childs
Patented Case
View Patent ↗
Granted: Aug 25, 1987
Filed: Mar 4, 1985
Inventors
Douglas W. J. Nayler
Fred R. Foreman
Willard D. Childs
Assignee (at issue)
NL Industries, 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.