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Expired Canadian patentCanada

Extruder

CA 1231813 A · Owner: Goodrich (B.F.) Company (The) · Inventors: Kim, Heung-Tai

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

An extruder apparatus for mixing polyvinyl chloride compounds wherein the extruder mixing screw has a feed section, a transition section and a metering section. The screw has a single helical flight that extends for the full length thereof. The pitch of the flights in the metering section are smaller in pitch that the other sections. In addition the metering section has a plurality of shear rings located along the axial length thereof with shear rings on such metering section.

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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 January 26, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 26, 2005.
  • 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 19, 1984
GrantedJanuary 26, 1988
Term endedJanuary 26, 2005
Patent numberCA 1231813 A
Classification (IPC)—

Timeline

Timeline From CIPO dates

1985198819911994199720002003Application filedJuly 19, 1984Patent grantedJan 26, 1988Term endedJan 26, 2005

Sources & verification

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