Direction correcting device for shield tunnelling machine
CA 2021203 C · Owner: Akesaka, Toshio · Inventors: Akesaka, Toshio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A direction correcting device for a shield tunnelling machine having a shield body provided with a head portion and a tail portion following the head portion is adapted to correct the direction of the head portion relative to the tail portion. The device comprises three jacks respectively having two connecting portions relatively displaced in the axial direction of the tail portion, and a connecting body for interconnecting the head portion and the tail portion so as to permit the head portion and the tail portion to swing while, preventing the head portion and the tail portion from relatively displacing in the axial direction of the tail portion. Each of the jacks is connected at one …
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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 July 13, 1990 and granted October 25, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 13, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 13, 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.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.