Blackboard
CA 2121663 C · Owner: Tsuar, Gwo-Nan · Inventors: Tsuar, Gwo-Nan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A blackboard includes a rectangular board member a, protective frame member provided on each side of the board member, and a tray connected to a lowermost one of the frame members and movable between an unfolded position for receiving erasers and writing implements and a folded position. The lowermost one of the frame members has a front side which is formed with a longitudinally extending retaining portion that confines a longitudinally extending space which is substantially L-shaped in cross-section. The tray has a rear side wall which is formed with a transversely and longitudinally extending rearward anchor projection that is substantially T-shaped in cross-section and that has a head …
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 19, 1994 and granted November 4, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 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.