Power tong wrench
CA 2179816 C · Owner: Richardson, Allan S. · Inventors: Richardson, Allan S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A power tong wrench having an open slot to accommodate a range of pipe diameters, capable of making and breaking pipe threads and spinning in or out the threads and in which hydraulic power is supplied with a pump disposed within a rotary assembly (10) which pump is powered through a preferably magnetic coupling (42) to a motor (41) disposed outside the rotary assembly (10).
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 January 31, 1995 and granted January 2, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 31, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 31, 2017.
- 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.