Granted Patent
Utility
US 4,542,639 · App. 06/596,154
Testing of structures by impact
Inventors:
Peter Cawley, Robert D. Adams
Patented Case
View Patent ↗
Granted: Sep 24, 1985
Filed: Apr 2, 1984
Inventors
Peter Cawley
Robert D. Adams
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT CORPORATION
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.