Teaching aid for mathematical tables and like calculations
CA 1264938 C · Owner: Jesser, Gregory Herbert · Inventors: Jesser, Gregory Herbert
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A teaching aid for multiplication tables the aid comprising, a tubular sleeve (5) with a cylindrical member (1) rotatably mounted in the sleeve (5). Two longitudinally oriented adjacent parallel rows of holes (9 and 10) in the sleeve (5) with a row of multiplicands marked on the sleeve (5) and positioned between the rows of holes (9 and 10) and respectively aligned therewith. The cylindrical member (1) has parallel rows of multiplier numerals and product numerals marked thereon with spacings between the rows ensuring that the products of numerals appearing in one row of holes (10) multiplied by the aligned multiplicands will appear in the holes (9) of the other row of holes.
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 January 30, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 30, 2007.
- 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.