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Expired Canadian patentCanada

Variable speed planter seed drive

CA 1075087 A · Owner: Deere And Company · Inventors: Harbert, Jimmy D.; Hansen, Harold V.

CIPO record

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

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Abstract From the Canadian patent

Abstract of the Disclosure An electrically adjusted and mechanically driven variable speed pulley transmission provides immediate and accurate changes to the seed dispensing rate of a planter. The variable speed pulley transmission is driven by a ground-engaging wheel and adjusted in response to electrically monitored variations between desired and actual seed plant densities. Adjustment to the sheaves of the transmission pulley is effected by an electric motor and tension springs which interconnect the movable pulley sheaves apply pressure to the sides of the pulley belt to assure torque transmission at low RPM's.

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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 8, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 8, 1997.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedApril 8, 1980
Term endedApril 8, 1997
Patent numberCA 1075087 A
Classification (IPC)A01C7/00 +2 more

Timeline

Timeline From CIPO dates

198119831985198719891991199319951997Patent grantedApril 8, 1980Term endedApril 8, 1997

Sources & verification

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