Apparatus for connecting and disconnecting threaded members
CA 2135400 C · Owner: Weatherford/Lamb, Inc. · Inventors: Schulze-Beckinghausen, Joerg-Erich
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
WO 90/06418 discloses a dynamic torque transmitting arrangement which inhibits a power tong and a back-up tong tending to move out of the axial alignment whilst coupling or uncoupling adjacent pipes. In the mechanical arrangement disclosed the minimum distance between the power tong and the back-up tong is limited by a strap. In the present invention flanges (122) are mounted on opposite sides of the top of the power tong (102). Tension arms (119 120) are pivotally mounted on the flanges and are connected by a hollow tube (121). Straps (117 118) are pivotally mounted at one end to the tension arms (119 120) and at the, other end to hollow pillars (115 116) on which the back-up tong (105) is …
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 28, 1993 and granted November 3, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 28, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 28, 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.