Granted Patent
Utility
US 4,938,404 · App. 07/380,125
Apparatus and method for ultrasonic control of web
Inventors:
Randall D. Helms, Robert A. Daane
Patented Case
View Patent ↗
Granted: Jul 3, 1990
Filed: Jul 14, 1989
Inventors
Randall D. Helms
Robert A. Daane
Assignee (at issue)
ADVANCED SYSTEMS, 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.