High back emf, high pressure subwoofer
CA 2263177 A1 · Owner: Carver, Robert W. · Inventors: Carver, Robert W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A subwoofer cabinet having a volume less than 1ft3; axially aligned openings in opposed cabinet walls; first and second cages mounted on respective ones of the walls in alignment with the openings; a voice coil driven driver including an annular 225 oz. magnet affixed to the first cage; a stationary pole piece extending through the magnet and defining a magnetic gap therebetween; a voice coil mounted on a cylindrical voice coil former positioned within the gap; a cone affixed to one end of the former; a first flexible surround secured to the outer end of the cone and attached at its periphery to the first cage; a flexible spider secured to the former and at its outer periphery to …
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 August 12, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 12, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 12, 2019.
- 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.