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Expired Canadian patentCanada

Sealing system for a sealed bearing assembly used in earth drilling

CA 2033779 C · Owner: Wenzel, Kenneth Hugo · Inventors: Foote, Dean; Wenzel, Kenneth Hugo

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

An improved sealing system for a sealed bearing assembly used in earth drilling. The bearing assembly has a first tubular member, and a second tubular member telescopically received in the first tubular member. The second tubular member has an interior passage through which drilling fluids pass under pressure from on surface pumps. A clearance space is provided between the first tubular and the second tubular member defining a lubricant filled bearing chamber. The improvement is in the seal at a pump end of the bearing chamber which consists of a first floating piston a second, floating piston spaced from the first floating piston and a, fixed seal intermediate the first floating piston and …

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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

  • Filed January 8, 1991 and granted January 7, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 8, 2011.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 8, 2013.
  • 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 8, 1991
GrantedJanuary 7, 1997
Term endedJanuary 8, 2011
Patent numberCA 2033779 C
Classification (IPC)E21B7/00 +2 more

Timeline

Timeline From CIPO dates

1992199419961998200020022004200620082010Application filedJan 8, 1991Patent grantedJan 7, 1997Term endedJan 8, 2011

Sources & verification

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