Filtration arrangement and method
CA 2094271 A1 · Owner: Donaldson Company, Inc. · Inventors: Dudrey, Denis J.; Kahlbaugh, Brad E.; Herman, John T.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Constructions and methods are described for collecting particulate material from gas streams. In one specifically described arrangement, a region of uniform or constant density depth media is oriented upstream of a region of gradient density depth media. In another, a preferred region of gradient density depth media is constructed, to effect particulate collection in a preferred manner. Preferred constructions described herein utilize a pleated paper filter oriented downstream of depth media to advantage.
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 29, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 29, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 29, 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.