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Expired Canadian patentCanada

Water-tight bore shaft foundation

CA 2045492 C · Owner: Lutgendorf, Hans-Otto · Inventors: Lutgendorf, Hans-Otto

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 lower end of an outwardly tight shaft structure (3) for a bore shaft (1) rests on a tilting joint arrangement (15 20). This arrangement includes a hydraulic thrust bearing (15) at the end face of the shaft structure (3) and a hydraulic annular cylinder (20) at the circumference of the lower end of the shaft structure (3). Thus this tilting, joint arrangement (15, 20) is located between the shaft structure (3) and the base (10) and permits tilting of the shaft structure (3) relative to the ground (12) without impairing the water-tightness of the bore shaft foundation.

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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 October 12, 1990 and granted October 27, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 12, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 12, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledOctober 12, 1990
GrantedOctober 27, 1998
Term endedOctober 12, 2010
Patent numberCA 2045492 C
Classification (IPC)E02D31/10 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedOct 12, 1990Patent grantedOct 27, 1998Term endedOct 12, 2010

Sources & verification

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