Load compensator for spring counter-weighting mechanism
CA 2098515 C · Owner: Greene, H. Peter · Inventors: Greene, H. Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved load compensator for a spring counter-weighting mechanism including a snail cam to provide a constant counter-weight force is described. The cam provides a constant torque to a drum on which are wound cables for exerting a constant counter-weighting force. A manually operable device for altering the relative radial positions of the cam and drum varies the amount of the constant counter-weighting force. The cam is rotated with respect to the drum by a spur gear fitting within a ring gear fixed to the drum and rotated by a knob connected to an axle carrying a pinion gear engaging the spur gear. The spiral surface can be effectively reconfigured with respect to a portion of the …
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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 June 16, 1993 and granted August 29, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 16, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 16, 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.