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Expired Canadian patentCanada

Headbox device for a papermaking machine

CA 1281222 C · Owner: Sulzer-Escher Wyss Gmbh · Inventors: Weisshuhn, Elmer; Holik, Herbert

CIPO record

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Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A fiber stock suspension is directed from a guide device through the nozzle chamber of the headbox device and out of the slice opening thereof onto a papermaking machine. This nozzle chamber comprises at least two zones or sections. The first zone subsequent to the guide device possesses a relatively low convergence angle or low angle of wall inclination of the headbox device relative to the direction of flow of the fiber stock suspension. The other or second zone is positioned prior to or immediately upstream of the slice opening and possesses a substantially greater convergence angle or angle of wall inclination. In the first zone subsequent to the guide device, an improved flow …

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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 March 12, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 12, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJuly 8, 1986
GrantedMarch 12, 1991
Term endedMarch 12, 2008
Patent numberCA 1281222 C
Classification (IPC)D21F1/02

Timeline

Timeline From CIPO dates

19871990199319961999200220052008Application filedJuly 8, 1986Patent grantedMarch 12, 1991Term endedMarch 12, 2008

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.