Granted Patent
Utility
US 4,663,574 · App. 06/802,673
Reactive position detector for electromagnetic vibrators
Inventor:
William H. Ward
Patented Case
View Patent ↗
Granted: May 5, 1987
Filed: Nov 29, 1985
Inventor
William H. Ward
Assignee (at issue)
Dresser 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.