Fans or the like
CA 1104103 A · Owner: Howden (James) And Company Limited · Inventors: Wilson, Robert R.; Falconer, Roy D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a centrifugal fan or the like including an impeller housed in a casing, recirculation means are provided to recycle a portion of the gas discharge back to the blades of the impeller. Specifically these means comprise a radial passage between an impeller shroud and a wall of the casing and aperture, means in the shroud. 15% to approximately 30% of the gas discharge may be recycled. This arrangement has the advantage of increasing the fan pressure at low discharge rates in comparison with previous fans with no gas recirculation, and this is advantageous in some fan installations where operation is at reduced rates for considerable periods.
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
- Granted June 30, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 30, 1998.
- 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.