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Expired Canadian patentCanada

Well clean out tool

CA 1208543 A · Owner: Bull Dog Tool Inc. · Inventors: Davis, Bob; Williams, Robert M.

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

The present invention relates to a well clean out tool comprising an elongated body having first and second ends and being adapted to be received within a well borehole. The elongated body is comprised of a plurality of subs including a first sub at a lower portion of the body having a one way valve for permitting only upward flow of fluid. A second sub is arranged above the first sub for receiving and retaining fluid and debris passing through the first sub while a third sub is arranged above the second sub. The third sub includes a second valve for permitting flow only upwardly through the third sub. A fourth or pumping sub is arranged above the third sub with the fourth sub including an …

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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 July 29, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 29, 2003.
  • 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 26, 1984
GrantedJuly 29, 1986
Term endedJuly 29, 2003
Patent numberCA 1208543 A
Classification (IPC)E21B37/00 +1 more

Timeline

Timeline From CIPO dates

1985198719891991199319951997199920012003Application filedApril 26, 1984Patent grantedJuly 29, 1986Term endedJuly 29, 2003

Sources & verification

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