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Expired Canadian patentCanada

Rotary rock and trench cutting saw

CA 1235151 A · Owner: H.B. Zachry Company · Inventors: Marten, Edward N.

CIPO record

Overview

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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 rotary trench cutting or rock milling saw unit is supported on a head for movement about two mutually perpendicular axes. The head is adapted for pivotal mounting on a backhoe boom or similar positioning structure. Rotary rock cutting wheels are driven by a hydraulic motor and a support vehicle for the saw unit includes a hydrostatic drive system with a variable displacement hydraulic pump driving variable displacement track drive motors which may be set in a slow speed operating mode for trench cutting operations or a high speed mode for tramming between work sites. A constant rate of power input to the saw unit is maintained by sensing saw drive motor supply pressure and adjusting tract …

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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 12, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 12, 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.
FiledMay 24, 1985
GrantedApril 12, 1988
Term endedApril 12, 2005
Patent numberCA 1235151 A
Classification (IPC)E21C25/00 +2 more

Timeline

Timeline From CIPO dates

1986198819901992199419961998200020022004Application filedMay 24, 1985Patent grantedApril 12, 1988Term endedApril 12, 2005

Sources & verification

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