Loudspeaker systems
CA 2288060 A1 · Owner: Nevill, Stuart Michael · Inventors: Nevill, Stuart Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The loudspeaker system comprises: a loudspeaker drive unit (2) and a tube (4) acoustically coupled to the rear of the loudspeaker drive unit for leading away and absorbing sound waves produced at the rear of the loudspeaker drive unit. The tube is acoustically coupled to the loudspeaker drive unit by means of a hollow resonant enclosure (6) and the loudspeaker drive unit is mounted at an aperture (8) in an external wall of the enclosure. The tube communicates with the interior of the enclosure and extends outwardly from the enclosure. There is a significant change in acoustic impedance where the tube communicates with the interior of the enclosure. The fundamental resonant …
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 April 29, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 29, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 29, 2020.
- 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.