Granted Patent
Utility
US 4,583,311 · App. 06/704,108
Combined changeable sign assembly
Inventors:
Richard E. Hosey, Ervan E. Rich
Patented Case
View Patent ↗
Granted: Apr 22, 1986
Filed: Feb 21, 1985
Inventors
Richard E. Hosey
Ervan E. Rich
Assignee (at issue)
Ashland Oil, 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.