Public address system
CA 2029048 A1 · Owner: Temmer, Stephen · Inventors: Temmer, Stephen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A public address system which consists of a longitudinal tubular member extending through an area serviced by the system with a longitudinal opening and having a plurality of speakers spaced at regular intervals. The audio signals generated from the speakers are emitted through the opening in any direction desired. The speakers are hidden from view within the tubular member and by a cover on the opening which further protects the speakers from ambient contamination. Preferably the tubular, member consists of modular sections each section including at, least one speaker. The speakers may be controlled through a speaker control 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
- Filed October 31, 1990. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 31, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 31, 2012.
- 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.