Support column
CA 2228666 C · Owner: Johnson, Robert · Inventors: Johnson, Robert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of preventing separation of a vertically adjustable support column having sections connected together by mating threads and a support column. External threads of a second section are mated with internal threads of a first section until a first end of the second section protrudes into an enlarged diameter portion of an interior bore of the first section immediately adjacent to the internal threads. A top few of the external threads at the first end of the second section are mechanically damaged. The mechanically damaged threads prevent the first end of the second section from being removed from the enlarged diameter portion of the first section but permit relative telescopic …
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 3, 1998 and granted April 9, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 3, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 3, 2020.
- 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.