Drilling of wells with top drive unit
CA 1194855 A · Owner: Varco International, Inc. · Inventors: Boyadjieff, George I.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Well drilling apparatus including a top drive drilling assembly having a motor driven stem adapted to be attached to the upper end of a drill string and drive it during a drilling operation, a torque wrench carried by the top drive assemly and movable upwardly and downwardly therewith and operable to break a threaded connection between the drill string and the stem, and an elevator carried by and suspended from the top drive assembly and adapted to engage a section of drill pipe beneath the torque wrench in suspending relation. The torque wrench and elevator are preferably retained against rotation with the rotary element which drives the drill string but, may be movable vertically relative …
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 October 8, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 8, 2002.
- 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.