Tunnel boring machine
CA 2056763 A1 · Owner: Hartwig, Sverker · Inventors: Hartwig, Sverker
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Tunnel boring machine whose driving shaft (4) adjacent to the boring head (6) is journalled in a bearing (12) which is intended to take up only radial forces. Shaft (4) is at its other end journalled in bearings (13,14) which take up both radial and axial forces. 90011.ut1
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 December 2, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 2, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 2, 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.
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.