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Expired Canadian patentCanada

Method and apparatus for forming an air gap pipe

CA 1252990 A · Owner: Ap Industries, Inc. · Inventors: Moring, Walter G. Iii; Resuggan, Peter L.; Rosa, Bruno A.

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

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Abstract From the Canadian patent

A process and an apparatus for forming an air gap pipe are provided. Inner and outer pipes are bent or deformed into comparable configurations such that the inner pipe can be mounted within the outer pipe. The outer pipe then is split longitudinally by a preprogrammed cutting apparatus. The cutting of the outer pipe terminates just short of the complete longitudinal length of the pipe to facilitate rematching later in the process. The cutter includes a follower to trace the actual configuration of the pipe and thereby to offset differences from one pipe to the next. An array of clamps are provided to align the outer pipe halves relative to one another and to facilitate the reattachment.

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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 April 25, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 25, 2006.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledJanuary 13, 1986
GrantedApril 25, 1989
Term endedApril 25, 2006
Patent numberCA 1252990 A
Classification (IPC)B21C37/15 +2 more

Timeline

Timeline From CIPO dates

1987198919911993199519971999200120032005Application filedJan 13, 1986Patent grantedApril 25, 1989Term endedApril 25, 2006

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