Wire line core drilling apparatus
CA 2010534 C · Owner: Williams, David Stanley · Inventors: Williams, David Stanley
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A wire line core barrel inner tube assembly has a latch body with a maximum diameter portion providing a shoulder seatable on a drill string landing ring and a fluid bypass channel extending through the maximum diameter portion and a valving assembly. The valving assembly includes a resilient valve seat in the bypass channel and a ball seatable on the valve seat to block fluid flow in a downward direction through the channel, movable upwardly off the valve seat from the seated position to permit fluid flow through the seat in the opposite direction and movable through the seat to a channel open condition after a preselected fluid pressure has been exerted on the ball in a direction to move …
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 21, 1990 and granted June 10, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 21, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 21, 2012.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.