Compact counterbalancing system for sectional doors
CA 2136332 C · Owner: Wayne-Dalton Corp. · Inventors: Mullet, Willis
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A counterbalancing mechanism (10) for a door (D) movable between a closed position proximate a door frame (12) and an open position displaced therefrom including a pair of drums (100 100) for reeving , lengths of cable (C) thereabout which are affixed to the door (D), shafts (70) for freely rotatably mounting the drums thereon a pair of , brackets (60, 60) mounted in spaced relation on the door frame one of the brackets supporting each of the pair of shafts a drive tube (30) , extending between the pair of drums and being non-rotatably affixed thereto, a coil spring (80) positioned interiorly of the drive tube said coil spring having one end (82) thereof non-rotatably affixed to the drive …
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 April 29, 1994 and granted July 29, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 29, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 29, 2016.
- 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.