Tennis racket
CA 1301798 C · Owner: Yonex Kabushiki Kaisha · Inventors: Yoneyama, Minoru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a tennis racket having a frame portion and a shaft portion formed integrally with the frame portion of a fiber-reinforced plastic, the shaft portion has in a direction perpendicular to a striking area a minimum thickness at a longitudinally intermediate part thereof, the minimum thickness being between 60% and 80% of the thickness at the lower end of the shaft portion, while the frame portion has in the same direction a maximum thickness at the side portions thereof corresponding to a striking sweet spot and a minimum thickness at the top thereof, the maximum thickness being between 110% and 140% of the thickness and being between 135% and 160% of the minimum thickness whereby a time …
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 May 26, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 26, 2009.
- 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.