Reverse circulation drilling system with bit locked underreamer arms
CA 2279224 A1 · Owner: Holte, Ardis L. · Inventors: Holte, Ardis L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A reverse circulation, pneumatic drilling assembly (10) wherein the bit assembly (11) is, operatively connected to a dual wall pipe assembly (12). A supply of compressed air is conducted, through the annulus of the dual wall pipe assembly (12) to a downhole pneumatic hammer (17). Exhaust air from the downhole pneumatic hammer is directed to the bit assembly (11) for continuous, removal of drilling debris through a central evacuation tube of the dual wall pipe assembly (12).
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 January 28, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 28, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 28, 2020.
- 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.