Drill pipe inside blowout preventer
CA 1234540 A · Owner: Hughes Tool Company-Usa · Inventors: Cunningham, Robert A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An inside blowout preventer for use in an earth boring drill string has features to reduce erosion. The blowout preventer has a valve body for connection into the drill string with a longitudinal passage extending through the body. The ball seat is located in the longitudinal passage. A ball storage location is located below the seat, and offset from the longitudinal passage. A ball is carried in the storage location during downward flow, and moves into the longitudinal passage to seat against the seat if the upward flow is sufficient. The storage location is located in an area of the longitudinal passage which has a much larger flow area than through the seat. The downward flow impinges on …
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
- Granted March 29, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 29, 2005.
- 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.