IP Library › Granted Patent US 4,558,305
Granted Patent Utility
US 4,558,305 · App. 06/450,965

Multiple tone signaling device

Inventors: Donald Black, Louis P. Sweany, James Pirtle
Patented Case View Patent ↗
Granted: Dec 10, 1985 Filed: Dec 20, 1982
Inventors
Donald Black
Louis P. Sweany
James Pirtle
Assignee (at issue)
Emhart Industries, Inc.

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Quick Facts
Patent No.
US 4,558,305
App. No.
06/450,965
Filed
1982-12-20
Granted
1985-12-10
Kind
A