Drill pipe
CA 2097366 A1 · Owner: Charles Machine Works Inc. (The) · Inventors: Martin, J. Scott; Stephenson, Brent G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A drill pipe (10) is disclosed which includes a cylindrical pipe section (12), a box end (14) a pin end, (16) and a hydraulic hose assembly (18) connected between the box and pin ends and extending within the cylindrical pipe section. By passing drilling fluid through the hydraulic hose assembly (18), the interior surface of the cylindrical pipe section (12) is not exposed to the drilling fluid and does not need to be treated to prevent corrosion. Further, the reduced volume of the hydraulic hose assembly (18) relative to conveying the drilling fluid through the interior of the cylindrical pipe section reduces significantly the waste of drilling fluid allows, the fluid to be pressurized …
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 May 31, 1993. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 31, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 31, 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.