String for use in racket
AssigneeSumitomo Rubber Industries, Ltd.
InventorsYuko SAKURAI, Takehiko HYODO, Masanori TAGUCHI, Kazuyoshi SHIGA, Hiroaki TANAKA, Kunio NIWA, Yuta SHIMANE
Life of this patent
Estimating the term…
Abstract
A method of manufacturing a string 10 for use in a racket includes: (A) preparing an untreated string; and (B) irradiating the untreated string with radioactive rays. Preferably, the untreated string is irradiated with gamma rays. A preferable irradiation amount of the radioactive rays is greater than or equal to 250 kGy but less than or equal to 2000 kGy. Preferably, a material of the untreated string is polyester. Alternatively, the material of the untreated string may be nylon.
Claims11
A method of manufacturing a string for use in a racket, the method comprising:
- (A) preparing an untreated string;
- and
- (B) irradiating the untreated string with radioactive rays.
A string for use in a racket, wherein
- an elongation rate P1 of the string when the string is tensioned to a stress of 217 MPa is higher than or equal to 9.25% but lower than or equal to 18.6%.
A string for use in a racket, wherein
- an elongation rate P2 of the string when the string is tensioned to a stress of 221 MPa is higher than or equal to 19.3% but lower than or equal to 22.0%.
A racket comprising a frame and a string, wherein
- an elongation rate P1 of the string when the string is tensioned to a stress of 217 MPa is higher than or equal to 9.25% but lower than or equal to 18.6%.
A racket comprising a frame and a string, wherein
- an elongation rate P2 of the string when the string is tensioned to a stress of 221 MPa is higher than or equal to 19.3% but lower than or equal to 22.0%.
Dependencies are inferred from the claim text.