Sound absorbing shaped part
CA 2124366 C · Owner: Carl Freudenberg Kg · Inventors: Stief, Reinhard; Mattutat, Manfred
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A sound absorbing shaped part includes at least two chambers which are adjacent in direction of incoming sound vibrations and during the intended use together with a carrier for the part delimit an interior space 3 which functions as an air-spring and is hermetically sealed to ambient. The chambers are each delimited by a chamber wall of polymeric material, whereby the chamber walls are joined into one piece and are relatively movably connected by an intermediate elastic element which is elastically deformable at least in direction of the incoming sound vibrations. The shaped part is more easily and economically manufactured and provides sound absorption over a wider range of frequencies.
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 May 26, 1994 and granted January 26, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 26, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 26, 2016.
- 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.