Speaker cabinet made of an injected mixture of polystyrene and hardwood powder
CA 2203871 A1 · Owner: Bouchard, Gilbert · Inventors: Bouchard, Gilbert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A speaker cabinet comprises a hollow rear member with an open front face, and a front driver-receiving board member for closing the open front face of the hollow rear member. The hollow rear member and the front board member are both made of a mixture of polystyrene and hardwood powder having a contents of 5-50% by weight of hardwood powder. To fabricate the speaker cabinet the mixture of polystyrene and, hardwood powder is melted and injected into mold cavities having the configuration of the hollow rear member and the front board member respectively. The hardwood powder improves the acoustic properties of the plastic material and therefore the resonance characteristic and …
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 28, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 28, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 28, 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.