Patents by Inventor Hidenori Hiraoka

Hidenori Hiraoka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5482285
    Abstract: A three-piece solid golf ball comprising an inner core 1a, an outer core 1b, and a cover formed principally of an ionomer resin, wherein said inner core 1a has a diameter of 10 to 38 mm, said outer core 1b has a specific gravity of 0.2 to 0.79 and has a diameter of 37 to 40 mm and a total weight of the inner core 1a and the outer core 1b is within the range of 32.0 to 39.0 g.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: January 9, 1996
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Yoshikazu Yabuki, Hidenori Hiraoka, Yoshimasa Koizumi
  • Patent number: 5482993
    Abstract: A rubber composition suitable for use in grips of articles such as golf clubs, tennis rackets, bicycles and tools, comprising (1) a rubber component containing a blend of an ethylene-propylene-diene rubber (EPDM) and natural rubber, (2) 2 to 40 parts by weight of a transpolyoctenamer per 100 parts by weight of the rubber blend, and (3) a filler containing a hydrated aluminum silicate powder, which provides grips having good non-slipping property, good feeling of touch and good response to mis-shot of golf balls.
    Type: Grant
    Filed: February 9, 1995
    Date of Patent: January 9, 1996
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventor: Hidenori Hiraoka
  • Patent number: 5215308
    Abstract: Disclosed is a solid golf ball containing at least one rubber portion formed from a rubber composition comprising a base rubber, a co-crosslinking agent and an organic peroxide; an improvement being present in that the base rubber is a mixture of(A) a solid polybutadiene rubber containing cis-1,4 bonds in an amount of at least 40%, and(B) either a liquid polybutadiene rubber or a liquid isoprene-butadiene copolymer rubber, or both.
    Type: Grant
    Filed: July 2, 1991
    Date of Patent: June 1, 1993
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Hidenori Hiraoka, Akihiko Hamada
  • Patent number: 5082285
    Abstract: The present invention provides a solid golf ball containing the ultra-high molecular weight polybutadiene which is formulated therein in a solution form. The golf ball has very improved impact resilience and durability. The present invention provides a solid golf ball having at least a resilient portion therein formed from a rubber composition which comprises a base rubber, a crosslinking agent and a co-crosslinking agent, wherein said base rubber comprises a solid polybutadiene prepared by mixing the following components in solution form(a) 5 to 50% by weight of an ultra-high molecular weight polybutadiene rubber which has a cis-1,4-bond of at least 80% and a number average molecular weight of 40.times.10.sup.4 or more, and(b) 95 to 50% by weight of a polybutadiene rubber which has a cis-1,4-bond of at least 80% and a number average molecular weight of less than 40.times.10.sup.4.
    Type: Grant
    Filed: October 30, 1990
    Date of Patent: January 21, 1992
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Akihiko Hamada, Hidenori Hiraoka
  • Patent number: 4974852
    Abstract: A one-piece golf ball exhibiting an increased flying distance and a high durability suitable for golf driving ranges, i.e. a solid golf ball having a central hardness (JIS-C hardness) of 60 to 75, a hardness at a position 10 mm from the center of 72 to 80 and a surface hardness of 70 to 85, whereby the central hardness is minimum, and the difference between the maximum hardness and the minimum hardness is 15 or less, said golf ball being obtained by vulcanizing and molding a rubber composition comprising(a) 100 parts by weight of polybutadiene rubber, mainly comprising high-cis-polybutadiene rubber containing the cis-1,4-structure in a quantity of at least 96% and having a Mooney viscosity of 48 to 85 synthesized by the use of a nickel-containing catalyst;(b) 0.1 to 2.0 parts by weight of 2,5-di-t-butylhydroquinone as a vulcanization stabilizer;(c) 10 to 50 parts by weight of unsaturated carboxylic acids and/or salts thereof; and(d) 0.5 to 5 parts by weight of a free radical initiator.
    Type: Grant
    Filed: December 26, 1989
    Date of Patent: December 4, 1990
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Hidenori Hiraoka, Katsutoshi Kitaoh, Kiyoto Maruoka, Mikio Yamada
  • Patent number: 4929678
    Abstract: A rubber composition for a solid golf ball comprising a rubber component containing at least 40% by weight of a polybutadiene rubber which has a Mooney viscosity [ML.sub.1+4 (100.degree. C.)] of 45 to 90 and a cis-1,4 bond of at least 80%, a co-crosslinking agent and a peroxide.
    Type: Grant
    Filed: January 14, 1988
    Date of Patent: May 29, 1990
    Assignee: Sumitomo Rubber Industries, Ltd.
    Inventors: Akihiko Hamada, Hidenori Hiraoka, Yoshinobu Nakamura, Hiroshi Ohtsuru