Shield tunneling machine
CA 2098138 A1 · Owner: Kabushiki Kaisha Isekikaihatsu Koki · Inventors: Akesaka, Toshio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A shield tunneling machine comprises a shield body. The shield body is divided into a soil chamber and an inside chamber by a partition wall. The soil chamber has 8 conical peripheral surface converging gradually rearward. A crankshaft having an eccentric portion is rotatably supported by the partition wall at the center of the partition wall corresponding to the axis of the shield body. A cutter disc with roller bits is secured to a front end of the crankshaft, and a conical rotor is rotatably mounted on the eccentric portion of the crankshaft behind the cutter disc . A rear end of the crankshaft is connected with a drive. Since the cutter disc is rotated at an increased rotary velocity by …
Read the whole patent
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 June 10, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 10, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 10, 2015.
- 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.