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Expired Canadian patentCanada

Enhanced heat transfer surface and apparatus and method of manufacture

CA 1291114 C · Owner: Zohler, Steven R. · Inventors: Zohler, Steven R.

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 apparatus and method for producing a high performance evaporator tube having a subsurface channel formed between adjacent helical fins with the subsurface channels having alternating closed portions and open pores above the subsurface channels. The fins of the tube are rolled-over toward the adjacent fin and then contacted with a notched disc to form the alternating closed portions and open pores.

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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 October 22, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 22, 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.
FiledApril 21, 1988
GrantedOctober 22, 1991
Term endedOctober 22, 2008
Patent numberCA 1291114 C
Classification (IPC)F28F13/18 +2 more

Timeline

Timeline From CIPO dates

1989199119931995199719992001200320052007Application filedApril 21, 1988Patent grantedOct 22, 1991Term endedOct 22, 2008

Sources & verification

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