Auxiliary driving device for a rolling door
CA 2043804 C · Owner: Hung, Chin Shan · Inventors: Hung, Chin Shan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An auxiliary driving device being attached to a primary driving device of a rolling door and including a gear engaged with a gear wheel of the primary driving device, a motor having an axle a lower disc with a, pinion slidably engaged on the axle a spring biasing the pinion and the, lower disc upward an upper disc disposed above the lower disc three balls, engaged in the recesses formed in the discs the pinion moves downwardly, to engage with the gear when the first motor is energized so that the spindle can be driven to rotate by the motor.
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 4, 1991 and granted April 2, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 4, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 4, 2013.
- 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.