Expired Canadian patentCanada
Handsfree loudspeaking key telephone set and a switching circuit for use in a microphone and loudspeaker equipped key telephone
CA 997492 A · Owner: Tie/Communications · Inventors: Murakami, Toyoshige; Shinoi, Tsuyoshi
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordRead 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 21, 1976. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 21, 1993.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedSeptember 21, 1976
Term endedSeptember 21, 1993
Patent numberCA 997492 A
Classification (IPC)H04M9/00 +1 more
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.