Loudspeakers
CA 2084787 C · Owner: Carrington, Simon Paul · Inventors: Carrington, Simon Paul
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved loudspeaker comprises an oscillator fitted to an enclosure and able to oscillate to create sound waves. The oscillator may be driven in response to an electromagnetic force or passively in response to pressures in the enclosure. The oscillator includes an air conduit which interconnects the interior of the enclosure with the exterior. The air conduit should provide a surface area in contact with air in excess to that provided by the diaphragm alone. Preferably it has a convoluted shape and may be either helical or formed from an interconnected series of substantially concentric circles. In a preferred embodiment the baffle forms a framework between two membranes one of …
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 June 7, 1991 and granted May 27, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 7, 2013.
- 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.