Multiple tone signaling device
CA 1193339 A · Owner: Emhart Industries, Inc. · Inventors: Pirtle, James D.; Sweany, Louis P.; Black, Donald E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multiple tone signaling device provides a piezoelectric transducer, first, second and third oscillator circuits a first input, terminal for enabling either or both of the first and second oscillator circuits, circuitry coupling the third oscillator circuit to the first and second oscillator circuits for disabling either the first or second oscillator circuits in response thereto and a second input terminal, coupled to the third oscillator circuit for allowing control of the output of said third oscillator circuit.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted September 10, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 10, 2002.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.