Pneumatic tire
CA 1332145 C · Owner: Bridgestone Corporation · Inventors: Takusagawa, Takashi; Yamaguchi, Kojiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
To prevent crack occurence at groove bottoms on both side areas of foam rubber tread of all-season studless tires, the pneumatic tire having a tread surface portion composed of at least two outer and inner rubber layers is characterized in that the hardness of the inner rubber layer lies from 54 to 80 degrees in Shore hardness and is higher than that of the outer rubber layer and further the, outer rubber layer is made of foam rubber with a foam rate from 5 to 50% with at least 10% volume ratio with respect to tread volume. The outer foam rubber layer serves to improve tire performance on icy and snowy roads in winter and the inner ordinary rubber layer serves to reduce change in groove …
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 September 27, 1994. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 27, 2011.
- 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.