Regenerative feedback door control device with one-way clutch
CA 2072180 A1 · Owner: Thomas Industries Inc. · Inventors: O'Brien, James A. Ii
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
REGENERATIVE FEEDBACK DOOR CONTROL DEVICE WITH ONE- WAY CLUTCH", A device for closing swinging doors of the type utilizing a rotating member to compress a spring during door opening to store energy in the spring to effect a closing of the door is provided with a driving connection to a d.c motor/generator effective to cause rotation of the motor during a closing movement of the door. The motor/generator acts as a generator during the closing with the generated electrical energy fed back to the motor/generator to retard rotation of the rotor, providing a brake on the closing movement of the door. The feedback circuitry includes a switch disabling or diminishing the braking during the final …
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 June 23, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 23, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 23, 2014.
- 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.