Chair height adjustment mechanism
CA 2005701 C · Owner: Jann, James · Inventors: Jann, James
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This chair height adjustment mechanism has a tubular housing fixed to the chair base, with vertically-space bearings providing lateral support for a threaded spindle secured to the chair seat. The upper bearing permits the spindle to move axially, and a nut in threaded engagement with the spindle below the upper bearing is biased upward into clutch engagement with the lower end of this bearing. The biasing spring acts between washers keyed to the spindle, the lower of these being supported by the upper face of the lower spindle bearing. Weight on the seat moves the spindle downward against the spring action to disengage the nut so it can rotate with the spindle thus, removing any change in …
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 December 15, 1989 and granted February 15, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 15, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 15, 2011.
- 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.