Patents by Inventor Takahiro Sajima

Takahiro Sajima 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: 11839795
    Abstract: An object of the present disclosure is to provide a golf ball having excellent durability and flight distance and good shot feeling for an average golfer who hits a golf ball at a slow head speed. The present disclosure provides a golf ball comprising a spherical core and at least two cover layers covering the spherical core, wherein a difference between a core surface crosslinking density and a core center crosslinking density is more than 1.0×102 mol/m3 and less than 9.0×102 mol/m3, a hardness difference between a core surface hardness Cs (Shore C hardness) and a core center hardness Co (Shore C hardness) is 13.0 or more and 30.0 or less, a compression deformation amount of the core when applying a load from an initial load of 98 N to a final load of 1275 N to the core is less than 3.
    Type: Grant
    Filed: September 20, 2022
    Date of Patent: December 12, 2023
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro Sajima, Daijiro Kojima, Hikaru Nagakura
  • Patent number: 11833396
    Abstract: An object of the present disclosure is to provide a golf ball having excellent durability and flight distance and good shot feeling for an average golfer who hits a golf ball at a slow head speed. The present disclosure provides a golf ball comprising a spherical core and at least two cover layers covering the spherical core, wherein a difference between a core surface crosslinking density and a core center crosslinking density is more than 1.0×102 mol/m3 and less than 9.0×102 mol/m3, a hardness difference between a core surface hardness Cs (Shore C hardness) and a core center hardness Co (Shore C hardness) is 13.0 or more and 30.0 or less, a compression deformation amount of the core when applying a load from an initial load of 98 N to a final load of 1275 N to the core is 3.
    Type: Grant
    Filed: September 20, 2022
    Date of Patent: December 5, 2023
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Daijiro Kojima, Takahiro Sajima, Hikaru Nagakura
  • Patent number: 11724161
    Abstract: A golf ball includes a core and a cover positioned outside the core. An n-layer (n is a natural number) partial mid layer is provided between the core and the cover. An area of the core in a region where the cover is laminated thereon is not less than 5.0% and not greater than 95.0% of a surface area of a phantom sphere having a radius equal to an average value of a distance from a central point of the core to a surface of the core. In an outer surface of the golf ball, a color difference ?E1 based on a CIELAB color system between a region C where the cover is directly laminated on the core and a region M where the cover is laminated on the partial mid layer is not less than 20.0.
    Type: Grant
    Filed: August 6, 2021
    Date of Patent: August 15, 2023
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Toshiyuki Takubo, Takahiro Sajima
  • Publication number: 20230241460
    Abstract: A golf ball can have a relatively large number of dimples on a surface thereof. A trajectory of the golf ball calculated under conditions of an initial speed of 260 ft/s, a launch angle of 15.0 degrees, and an initial backspin rate of 3000 rpm can satisfy the following mathematical formula: Amin??5.0*Vave?38.98, wherein A min represents a minimum value (degree) of a vector angle A in the trajectory, and Vave represents an average volume (mm3) of the dimples. The vector angle A can be calculated by the following mathematical formula: A=ATAN(Vy/Vx), wherein Vx represents a horizontal component of a speed of the golf ball, and Vy represents a vertical component of the speed of the golf ball.
    Type: Application
    Filed: January 31, 2023
    Publication date: August 3, 2023
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Daijiro KOJIMA, Takahiro SAJIMA
  • Publication number: 20230241459
    Abstract: A golf ball can have a large number of dimples on a surface thereof. A trajectory of the golf ball can be calculated under conditions of an initial speed of 260 ft/s, a launch angle of 15.0 degrees, and an initial backspin rate of 3000 rpm satisfying the following mathematical formula, Amax ? 4 .0 ? * ? Vave + 13 .10, wherein Amax represents a maximum value (degree) of a vector angle A in the trajectory, and Vave represents an average volume (mm3) of the dimples. The vector angle A can be calculated by the mathematical formula A = ATAN Vy / Vx , wherein Vx represents a horizontal component of a speed of the golf ball, and Vy represents a vertical component of the speed of the golf ball.
    Type: Application
    Filed: January 31, 2023
    Publication date: August 3, 2023
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Takahiro SAJIMA, Daijiro KOJIMA
  • Patent number: 11712605
    Abstract: A golf ball includes a core, a mid layer, and a cover. An amount of compressive deformation C3 of the golf ball can be not less than 2.80 mm. The golf ball can satisfy the following mathematical formulas (1) and (2): C1>(124.8?Hs)/11.5??(1) C2?C1?(?1/6*C1+(68?H2)/20+(5?Hd)/100)*T2??(2), where C1 is an amount of compressive deformation (mm) of the core, C2 is an amount of compressive deformation (mm) of a sphere including the core and the mid layer, Hd is Hs?Ho, Ho is a hardness (Shore C) of a center the core, Hs is a hardness (Shore C) of a surface of the core, H2 is a hardness (Shore D) of the mid layer, and T2 is a thickness (mm) of the mid layer.
    Type: Grant
    Filed: November 24, 2021
    Date of Patent: August 1, 2023
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Toshiyuki Takubo, Takahiro Sajima
  • Publication number: 20230103376
    Abstract: An object of the present disclosure is to provide a golf ball having excellent durability and flight distance and good shot feeling for an average golfer who hits a golf ball at a slow head speed. The present disclosure provides a golf ball comprising a spherical core and at least two cover layers covering the spherical core, wherein a difference between a core surface crosslinking density and a core center crosslinking density is more than 1.0×102 mol/m3 and less than 9.0×102 mol/m3, a hardness difference between a core surface hardness Cs (Shore C hardness) and a core center hardness Co (Shore C hardness) is 13.0 or more and 30.0 or less, a compression deformation amount of the core when applying a load from an initial load of 98 N to a final load of 1275 N to the core is less than 3.
    Type: Application
    Filed: September 20, 2022
    Publication date: April 6, 2023
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Takahiro SAJIMA, Daijiro KOJIMA, Hikaru NAGAKURA
  • Publication number: 20230089974
    Abstract: An object of the present disclosure is to provide a golf ball having excellent durability and flight distance and good shot feeling for an average golfer who hits a golf ball at a slow head speed. The present disclosure provides a golf ball comprising a spherical core and at least two cover layers covering the spherical core, wherein a difference between a core surface crosslinking density and a core center crosslinking density is more than 1.0×102 mol/m3 and less than 9.0×102 mol/m3, a hardness difference between a core surface hardness Cs (Shore C hardness) and a core center hardness Co (Shore C hardness) is 13.0 or more and 30.0 or less, a compression deformation amount of the core when applying a load from an initial load of 98 N to a final load of 1275 N to the core is 3.
    Type: Application
    Filed: September 20, 2022
    Publication date: March 23, 2023
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Daijiro KOJIMA, Takahiro SAJIMA, Hikaru NAGAKURA
  • Patent number: 11547908
    Abstract: A golf ball has a core, an inner cover, an outer cover, and dimples. The golf ball satisfies the following mathematical formulas. Sa=4500+10(A?0.5B?2Cs)?4000 0.04Sa+160?20?D?0.
    Type: Grant
    Filed: October 23, 2020
    Date of Patent: January 10, 2023
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventor: Takahiro Sajima
  • Publication number: 20220409962
    Abstract: A golf ball 2 includes a core 4, an inner cover 6, and an outer cover 8. The golf ball 2 satisfies the following mathematical formulas (1), (2), and (3): 5?(Hi*Ti?Dc*Rc)?40??(1); 5?(Hi*Ti?Ho*To)?40??(2); and ?20?(Ho*To?Dc*Rc)?20??(3). Dc is the amount of compressive deformation (mm) of the core 4, Rc is the radius (mm) of the core 4, Hi is the Shore C hardness of the inner cover 6, Ti is the thickness (mm) of the inner cover 6, Ho is the Shore C hardness of the outer cover 8, and To is the thickness (mm) of the outer cover 8.
    Type: Application
    Filed: June 3, 2022
    Publication date: December 29, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventor: Takahiro SAJIMA
  • Publication number: 20220409961
    Abstract: A golf ball includes an assist mark 10 and a guide mark. The assist mark is straight in plan. The guide mark is distorted in plan. The guide mark is in the shape of an arrow as a whole. The guide mark looks straight to a player swinging a golf club. The player moves the head of the golf club along the direction of the guide mark.
    Type: Application
    Filed: June 13, 2022
    Publication date: December 29, 2022
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro SAJIMA, Hidetaka INOUE
  • Patent number: 11433279
    Abstract: A golf ball can include a core, a mid layer, and a cover. The golf ball can satisfy the following mathematical formulas (1), (2), and (3): C1?(124.8?Hs)/11.5??(1) C2?C1?(?1/6*C1+(68?H2)/20+(5?Hd)/100)*T2?? (2) 10?H2*T2?H3*T3??(3), where C1 is an amount of compressive deformation (mm) of the core, C2 is an amount of compressive deformation (mm) of a sphere including the core and the mid layer, Hd is Hs?Ho, Ho is a hardness (Shore C) of a center the core, Hs is a hardness (Shore C) of a surface of the core, H2 is a hardness (Shore D) of the mid layer, H3 is a hardness (Shore D) of the cover, T2 is a thickness (mm) of the mid layer, and T3 is a thickness (mm) of the cover.
    Type: Grant
    Filed: December 6, 2021
    Date of Patent: September 6, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro Sajima, Toshiyuki Takubo
  • Patent number: 11426634
    Abstract: A golf ball according to an aspect of the present invention is a golf ball having a large number of dimples, a surface of the golf ball is covered with a plurality of virtual flat surfaces each having a triangular shape, one or more dimples are arranged so as to correspond to each of the virtual flat surfaces, and an edge of each dimple is formed in a linear shape. Each dimple may have a triangular pyramid shape or a triangular frustum shape.
    Type: Grant
    Filed: December 3, 2019
    Date of Patent: August 30, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro Sajima, Toshiyuki Takubo
  • Patent number: 11413504
    Abstract: A golf ball includes a core and a cover. An n-layer (n is a natural number) partial mid layer is provided between the core and the cover. An area of the core in a region where the cover is laminated thereon is not less than 5.0% and not greater than 95.0% of a surface area of a phantom sphere. A hitting feel index Cx calculated using a thickness T0 (mm) of the cover laminated on the partial mid layer, a Shore D hardness Ck of a kth layer (k is an integer from 1 to n) from the core side, a thickness Tk (mm) of the kth layer, a Shore D hardness C of the cover, and an average thickness T (mm) of the cover, is less than 66.0. An absolute value |Cx?C| is not less than 1.0 and not greater than 5.0.
    Type: Grant
    Filed: August 6, 2021
    Date of Patent: August 16, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro Sajima, Toshiyuki Takubo
  • Publication number: 20220193496
    Abstract: A golf ball can include a core, a mid layer, and a cover. The golf ball can satisfy the following mathematical formulas (1), (2), and (3): C1?(124.8?Hs)/11.5??(1) C2?C1?(??*C1+(68?H2)/20+(5?Hd)/100)*T2??(2) 10?H2*T2?H3*T3??(3), where C1 is an amount of compressive deformation (mm) of the core, C2 is an amount of compressive deformation (mm) of a sphere including the core and the mid layer, Hd is Hs?Ho, Ho is a hardness (Shore C) of a center the core, Hs is a hardness (Shore C) of a surface of the core, H2 is a hardness (Shore D) of the mid layer, H3 is a hardness (Shore D) of the cover, T2 is a thickness (mm) of the mid layer, and T3 is a thickness (mm) of the cover.
    Type: Application
    Filed: December 6, 2021
    Publication date: June 23, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Takahiro SAJIMA, Toshiyuki TAKUBO
  • Publication number: 20220193495
    Abstract: A golf ball includes a core, a mid layer, and a cover. An amount of compressive deformation C3 of the golf ball can be not less than 2.80 mm. The golf ball can satisfy the following mathematical formulas (1) and (2): C1>(124.8?Hs)/11.5 ??(1) C2?C1?(?1/6*C1+(68?H2)/20+(5?Hd)/ 100)*T2 ??(2), where C1 is an amount of compressive deformation (mm) of the core, C2 is an amount of compressive deformation (mm) of a sphere including the core and the mid layer, Hd is Hs?Ho, Ho is a hardness (Shore C) of a center the core, Hs is a hardness (Shore C) of a surface of the core, H2 is a hardness (Shore D) of the mid layer, and T2 is a thickness (mm) of the mid layer.
    Type: Application
    Filed: November 24, 2021
    Publication date: June 23, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Toshiyuki Takubo, Takahiro Sajima
  • Publication number: 20220143471
    Abstract: A golf ball 2 includes a core 4, an inner cover 6 positioned outside the core 4, and an outer cover 8 positioned outside the inner cover 6. The core 4 has a capsule 14, a plurality of separators 16, an electronic unit 18, and a plurality of fillings 20. The capsule 14 has a melting point of not lower than 100° C. A ratio P1 of a volume Vr of the capsule 14 to a volume Vc of the core 4 is not less than 25% and not greater than 75%. The electronic unit 18 is housed in the capsule 14. The electronic unit 18 detects behavior of the golf ball 2.
    Type: Application
    Filed: October 6, 2021
    Publication date: May 12, 2022
    Applicant: Sumitomo Rubber Industries, Ltd.
    Inventors: Toshiyuki TAKUBO, Takahiro SAJIMA, Kuniyasu HORIUCHI, Hiroshi SHINOHARA, Jiro MORI, Tsuyoshi ITO, Masanobu YOSHIDA, Kazuya KAMINO, Hidetaka INOUE, Masahide ONUKI
  • Patent number: 11285363
    Abstract: A golf ball 2 includes a core 4 and a cover 6 positioned outside the core 4. The cover 6 is formed in a mold having support pins by injection molding. A ratio (V/S) of a volume V (mm3) of the cover 6 to an amount of compressive deformation S (mm) of the core 4 is not less than 1000 and not greater than 1900. The cover 6 has a shore D hardness of not greater than 62. The golf ball 2 has a plurality of dimples 8 on a surface thereof. A total volume W of these dimples is not less than 490 mm3 and not greater than 620 mm3. A ratio (?/P) of a latitude ? (degree) of each support pin to a total cross-sectional area P (mm2) of the support pins is not less than 0.35 and not greater than 0.60.
    Type: Grant
    Filed: April 14, 2020
    Date of Patent: March 29, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro Sajima, Hironori Takihara
  • Patent number: 11266881
    Abstract: A golf ball has a plurality of dimples 12 and a land 14 on a surface thereof. The golf ball further has a large number of minute projections 18 formed on surfaces of the dimples 12 and the land 14. The surface of the golf ball has an arithmetic average height Sa of not less than 0.5 ?m and not greater than 30 ?m. An average value Hav of heights H of the minute projections 18 is not less than 0.5 ?m and not greater than 50 ?m. A ratio Pp of a sum of areas of all the minute projections 18 to a surface area of a phantom sphere of the golf ball is not less than 7%. An average value Dav of diameters D of the minute projections 18 is not less than 5 ?m and not greater than 50 ?m.
    Type: Grant
    Filed: November 9, 2020
    Date of Patent: March 8, 2022
    Assignee: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro Sajima, Hironori Takihara, Toshiyuki Takubo
  • Publication number: 20220062710
    Abstract: A golf ball includes a core and a cover. An n-layer (n is a natural number) partial mid layer is provided between the core and the cover. An area of the core in a region where the cover is laminated thereon is not less than 5.0% and not greater than 95.0% of a surface area of a phantom sphere. A hitting feel index Cx calculated using a thickness T0 (mm) of the cover laminated on the partial mid layer, a Shore D hardness Ck of a kth layer (k is an integer from 1 to n) from the core side, a thickness Tk (mm) of the kth layer, a Shore D hardness C of the cover, and an average thickness T (mm) of the cover, is less than 66.0. An absolute value |Cx?C| is not less than 1.0 and not greater than 5.0.
    Type: Application
    Filed: August 6, 2021
    Publication date: March 3, 2022
    Applicant: SUMITOMO RUBBER INDUSTRIES, LTD.
    Inventors: Takahiro SAJIMA, Toshiyuki TAKUBO