Pressureless tennis ball
AssigneeSumitomo Rubber Industries, Ltd.
InventorsKuniyasu Horiuchi, Yoshinobu Nakamura
Life of this patent
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Abstract
A pressureless tennis ball which has excellent rebound properties and produces a satisfactory feeling of striking retained over a long period of time, the tennis ball having a hollow spherical core made from a rubber composition containing a rubber and 5 to 60 parts by weight of polyethylene per 100 parts by weight of the rubber.
Claims3
A pressureless tennis ball comprising a hollow spherical core and a cover affixed thereon, said core being made of a rubber composition comprising a rubber being at least one member selected from the group consisting of natural rubber, cis-1,4-polybutadiene and a styrene-butadiene rubber, and 5 to 60 parts by weight of a polyethylene per 100 parts by weight of said rubber, said polyethylene having an average molecular weight of at least 30,000, a shore D hardness of 45 to 75 and a flexural rigidity of 2,000 to 7,000 kg/cm.sup.2.
Dependencies are inferred from the claim text.