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Expired Canadian patentCanada

Papermaking dryer section with partitioned vacuum box for threading

CA 2216048 C · Owner: Mitsubishi Heavy Industries, Ltd. · Inventors: Grunder, Thomas K.

CIPO record

Overview

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 single tier dryer system has dryer rolls with a reversing roll positioned between each pair to transfer and wrap the dryer felt and paper web against the next dryer roll. A vacuum box is positioned between the dryer rolls and over the reversing roll to hold the web on the dryer felt by vacuum. Threading of a tail from the web is accomplished by blowing the web tail off a first dryer roll's surface with a jet of air positioned adjacent to the position on the dryer roll where the dryer felt leaves the dryer roll's surface. The vacuum box is divided by a baffle to isolate a portion of the vacuum box near the front of the dryer rolls, and a damper is positioned within the reversing roll to …

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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

  • Filed September 17, 1997 and granted November 12, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 17, 2017.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 17, 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.
FiledSeptember 17, 1997
GrantedNovember 12, 2002
Term endedSeptember 17, 2017
Patent numberCA 2216048 C
Classification (IPC)D21F1/50 +2 more

Timeline

Timeline From CIPO dates

1998200020022004200620082010201220142016Application filedSep 17, 1997Patent grantedNov 12, 2002Term endedSep 17, 2017

Sources & verification

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