Educational device
CA 1233982 A · Owner: Stuart, Marion W. · Inventors: Stuart, Marion W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to an educational device having a card with notched edges and a series of numbers or words along each longitudinal edge of the card corresponding to each notch. The correct answer to a problem from one edge of the card, whether arithmetic or grammatical or historical is found on the opposite, edge of the card. A string member is used to connect the problem on one edge of the card with the correct answer on the other edge. The reverse side of the card has the correct string lines imprinted thereon corresponding to the correct placement of the string member for the correct answers to the problems on the face side of the card.
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
- Granted March 15, 1988. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 15, 2005.
- 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.