Down-the-hole drill tool for drilling in advance of a casing tube
CA 2075900 C · Owner: Sandvik Ab · Inventors: Asberg, Bengt; Brungs, Anders; Hedlund, Jan-Gunnar
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a down-the-hole drill tool said drill tool , be-, ing adapted to drill a hole in advance of a trailing casing tube (15) said , drill tool in-, cluding a central pilot bit (12) and a reamer means (14) and a guide means (17; 17';, 17"; 17"'; 17"", 37) for guiding the drill tool and said casing tube (15) relative to, one another, and a shaft (11; 11'; 11"; 11"') that is adapted to be connected to a, down-the-hole hammer (23). The invention also relates to a guide means and a one-, piece unit per se. In known drill tools of the above-mentioned type the thread con-, nection, e.g. between the guide means and the portion supporting the reamer is the, weak …
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 February 15, 1991 and granted December 2, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 15, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 15, 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.