Patents by Inventor Takahiro Yamakawa

Takahiro Yamakawa 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).

  • Publication number: 20150298508
    Abstract: A tread pattern of a pneumatic tire includes two outer circumferential main grooves and two inner circumferential main grooves. Each of the two inner circumferential main grooves comprises a first groove wall and a second groove wall facing the first groove wall. The first groove walls include first oblique wall elements that extend obliquely outward in a tire width direction and second oblique wall elements that extend obliquely inward in the tire width direction and extend for a shorter length than the first oblique wall elements. The second groove walls include third oblique wall elements that extend obliquely inward in the tire width direction and fourth oblique wall elements that extend obliquely outward in the tire width direction and extend for a shorter length than the third oblique wall elements.
    Type: Application
    Filed: January 28, 2014
    Publication date: October 22, 2015
    Applicant: The Yokohama Rubber Co., LTD.
    Inventors: Takahiro YAMAKAWA, Yasutaka AKASHI
  • Publication number: 20150273951
    Abstract: Provided is a pneumatic tire with a tread pattern that includes two first circumferential main grooves, shoulder land portions, shoulder lug grooves, shoulder sipes, and narrow circumferential grooves, the shoulder lug grooves being closed off midway in the region of the shoulder land portions without connecting with the first circumferential main grooves and including first regions and second regions that are disposed in the regions closer to the first circumferential main grooves than the first regions and have a groove depth that is less than that of the first regions. The shoulder sipes are connected with the second regions and extend toward the first circumferential main grooves. The narrow circumferential grooves extend in the tire circumferential direction and have a groove width that is less than the groove width of the shoulder lug grooves. The narrow circumferential grooves intersect with the second regions of the shoulder lug grooves.
    Type: Application
    Filed: March 6, 2014
    Publication date: October 1, 2015
    Applicant: The Yokohama Rubber Co., LTD.
    Inventor: Takahiro Yamakawa
  • Publication number: 20150202928
    Abstract: A tread pattern on a pneumatic tire is provided in regions of two intermediate land portions and has circumferential shallow grooves extending in the tire circumferential direction. An orientation of a groove inclination inclined with respect to a first direction in the tire circumferential direction of lug grooves provided in a region of one intermediate land portion, is the same as an orientation of a groove inclination inclined with respect to a second direction opposite to of the first direction of the tire circumferential direction of lug grooves provided in a region of another intermediate land portion, and the lug grooves provided in the respective regions of the intermediate land portions are bent so that the groove inclination approaches the tire circumferential direction at positions of intersection with the circumferential shallow grooves.
    Type: Application
    Filed: December 30, 2014
    Publication date: July 23, 2015
    Inventors: Yasutaka Akashi, Takahiro Yamakawa
  • Patent number: 9027612
    Abstract: Provided is a pneumatic tire whose braking performance on ice and partial-wear resistance can be improved. Sipes 11X provided in a rib 5 on a tire equatorial plane TE are formed in such a three-dimensional shape that the amount at which the rib 5 collapses due to an external force is smaller in the tire rotational direction than in a direction opposite to the tire rotational direction. In each block 10 in each shoulder region 1S, sipes 11Ma in a block tread-in side portion 10A are each formed in such a three-dimensional shape that the amount at which the block 10, if entirely provided with the sipes 11Ma, collapses due to an external force will be smaller in the tire rotational direction than in the direction opposite to the tire rotational direction.
    Type: Grant
    Filed: June 19, 2009
    Date of Patent: May 12, 2015
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventor: Takahiro Yamakawa
  • Publication number: 20150000815
    Abstract: The side wall portion of this pneumatic tire has a pattern visibly distinguished from the surrounding region. The pattern has: a first pattern element region at which are formed a pair of first reduced regions, which are provided on a line linking a pair of corners in a first demarcated section containing a pair of corners that are opposite each other, and a first primary region, which is visibly distinguished from the first reduced regions; and a second pattern element region at which are formed a pair of second reduced regions, which have the same unevenness or light reflection characteristics as the first primary region and are provided on a line linking a pair of corners in a second demarcated section containing a pair of corners that are opposite each other, and a second primary region, which has the same unevenness or light reflection characteristics as the first reduced region.
    Type: Application
    Filed: January 11, 2013
    Publication date: January 1, 2015
    Inventor: Takahiro Yamakawa
  • Patent number: 8813801
    Abstract: A pneumatic tire has a tread surface for simultaneously achieving both enhanced on-ice performance and enhanced durability. The pneumatic tire includes sipes extending in the width direction of the tire that are arranged at intervals in the circumferential direction of the tire at least in shoulder blocks that are divided by longitudinal grooves extending in the circumferential direction of the tire and by lateral grooves extending in the width direction of the tire. Open sipes and closed sipes are alternately arranged, and the depth of the open sipes is less than the depth of the closed sipes.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: August 26, 2014
    Assignee: The Yokohama Rubber Co., Ltd
    Inventor: Takahiro Yamakawa
  • Patent number: 8794284
    Abstract: A pneumatic tire includes a tread portion extending in a tire circumferential direction and a pair of sidewall sections disposed on both sides of the tread portion in a tire width direction. At least one sidewall section includes a surface pattern region having a plurality of minute regions arranged along the circumferential direction and a tire radial direction. The minute regions are visually distinguishable from surrounding regions due to light reflection characteristics or surface unevenness. Width dimensions along the circumferential direction of adjacent minute regions juxtaposed with each along the circumferential direction vary among at least three different widths. The width dimensions of adjacent minute sections vary continuously or in steps along the circumferential direction. The adjacent minute regions are juxtaposed next to each other at at least three different interval sizes, and are arranged along the circumferential direction at prescribed intervals whose sizes vary continuously or in steps.
    Type: Grant
    Filed: December 16, 2011
    Date of Patent: August 5, 2014
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventor: Takahiro Yamakawa
  • Patent number: 8720512
    Abstract: A pneumatic tire having inconspicuous sidewall surface irregularities. The pneumatic tire includes a plurality of sidewall parts and a tread portion extending between the sidewall parts. At least one sidewall part has a pattern extending in the tire circumferential direction that can be visually differentiated from the surrounding regions of the sidewall surface by an irregularity or reflectance properties of light of the sidewall surface. The pattern includes a plurality of linear protrusions or grooves that extend in a wave shape in a tire circumferential direction while deflecting in a tire radial direction with a period of ?1. The line protrusions or grooves have intervals in a tire radial direction, and are non-intersecting. Outer and inner circumferences of the pattern of the tire radial direction are formed by the plurality of linear protrusions or grooves to extend in a wave shape in a tire circumferential direction.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: May 13, 2014
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventor: Takahiro Yamakawa
  • Patent number: 8646503
    Abstract: A pneumatic tire includes a tread portion extending in a tire circumferential direction and a pair of sidewall sections on both sides of the tread portion, respectively, with regard to a tire width direction. At least one of the sidewall sections includes partitions and a plurality of first and second minute regions. The partitions have a prescribed spacing in the tire circumferential direction and extend linearly in a tire radial direction. The first and second minute regions are provided in each of a plurality of partitioned regions and are visually distinguishable from surrounding sidewall surface regions. The first minute regions are also visually distinguishable from the second minute regions. The first and second minute regions are provided alternately along the tire radial direction, and the radial positions of the first minute regions and the second minute regions are varied with respect to the tire circumferential direction.
    Type: Grant
    Filed: December 7, 2011
    Date of Patent: February 11, 2014
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventor: Takahiro Yamakawa
  • Patent number: 8474496
    Abstract: A pneumatic tire includes a pair of first circumferential main grooves formed in the center region of a tread, a pair of second circumferential main grooves formed respectively outward of the corresponding first main grooves, a plurality of first lug grooves which each extend from one of the two shoulder ends of the tread inward in the tire-width direction and communicate with the corresponding first main groove, a plurality of second lug grooves alternately arranged in the tire circumferential direction which each extend from one of the two shoulder ends of the tread inward in the tire-width direction but do not communicate with the corresponding first main groove, a center rib defined between the pair of first main grooves and extends continuously in the tire circumferential direction, a shoulder block row defined between each of the second main grooves and a corresponding one of the shoulder ends and includes a plurality of blocks, and an intermediate block row defined between each of the first main groove
    Type: Grant
    Filed: June 9, 2008
    Date of Patent: July 2, 2013
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventor: Takahiro Yamakawa
  • Publication number: 20120318423
    Abstract: A pneumatic tire having inconspicuous sidewall surface irregularities. The pneumatic tire includes a plurality of sidewall parts and a tread portion extending between the sidewall parts. At least one sidewall part has a pattern extending in the tire circumferential direction that can be visually differentiated from the surrounding regions of the sidewall surface by an irregularity or reflectance properties of light of the sidewall surface. The pattern includes a plurality of linear protrusions or grooves that extend in a wave shape in a tire circumferential direction while deflecting in a tire radial direction with a period of ?1. The line protrusions or grooves have intervals in a tire radial direction, and are non-intersecting. Outer and inner circumferences of the pattern of the tire radial direction are formed by the plurality of linear protrusions or grooves to extend in a wave shape in a tire circumferential direction.
    Type: Application
    Filed: May 29, 2012
    Publication date: December 20, 2012
    Applicant: THE YOKOHAMA RUBBER CO., LTD.
    Inventor: Takahiro YAMAKAWA
  • Publication number: 20120199261
    Abstract: A pneumatic tire includes a tread portion extending in a tire circumferential direction and a pair of sidewall sections disposed on both sides of the tread portion in a tire width direction. At least one sidewall section includes a surface pattern region having a plurality of minute regions arranged along the circumferential direction and a tire radial direction. The minute regions are visually distinguishable from surrounding regions due to light reflection characteristics or surface unevenness. Width dimensions along the circumferential direction of adjacent minute regions juxtaposed with each along the circumferential direction vary among at least three different widths. The width dimensions of adjacent minute sections vary continuously or in steps along the circumferential direction. The adjacent minute regions are juxtaposed next to each other at at least three different interval sizes, and are arranged along the circumferential direction at prescribed intervals whose sizes vary continuously or in steps.
    Type: Application
    Filed: December 16, 2011
    Publication date: August 9, 2012
    Applicant: THE YOKOHAMA RUBBER CO., LTD.
    Inventor: Takahiro YAMAKAWA
  • Publication number: 20120152427
    Abstract: A pneumatic tire includes a tread portion extending in a tire circumferential direction and a pair of sidewall sections on both sides of the tread portion, respectively, with regard to a tire width direction. At least one of the sidewall sections includes partitions and a plurality of first and second minute regions. The partitions have a prescribed spacing in the tire circumferential direction and extend linearly in a tire radial direction. The first and second minute regions are provided in each of a plurality of partitioned regions and are visually distinguishable from surrounding sidewall surface regions. The first minute regions are also visually distinguishable from the second minute regions. The first and second minute regions are provided alternately along the tire radial direction, and the radial positions of the first minute regions and the second minute regions are varied with respect to the tire circumferential direction.
    Type: Application
    Filed: December 7, 2011
    Publication date: June 21, 2012
    Applicant: THE YOKOHAMA RUBBER CO., LTD.
    Inventor: Takahiro YAMAKAWA
  • Publication number: 20110162770
    Abstract: A pneumatic tire simultaneously achieving both enhanced on-ice performance and enhanced durability. A pneumatic tire, wherein sipes (6) extending in the width direction of the tire are arranged at intervals in the circumferential direction of the tire at least in shoulder blocks (5a) divided by longitudinal grooves (2) extending in the circumferential direction of the tire and by lateral grooves (3) extending in the width direction of the tire. Open sipes (6a) and closed sipes (6b) are alternately arranged, and the depth of the open sipes (6a) is less than the depth of the closed sipes (6b).
    Type: Application
    Filed: September 11, 2009
    Publication date: July 7, 2011
    Applicant: THE YOKOHAMA RUBBER CO., LTD.
    Inventor: Takahiro Yamakawa
  • Publication number: 20110100519
    Abstract: Provided is a pneumatic tire whose braking performance on ice and partial-wear resistance can be improved. Sipes 11X provided in a rib 5 on a tire equatorial plane TE are formed in such a three-dimensional shape that the amount at which the rib 5 collapses due to an external force is smaller in the tire rotational direction than in a direction opposite to the tire rotational direction. In each block 10 in each shoulder region 1S, sipes 11Ma in a block tread-in side portion 10A are each formed in such a three-dimensional shape that the amount at which the block 10, if entirely provided with the sipes 11Ma, collapses due to an external force will be smaller in the tire rotational direction than in the direction opposite to the tire rotational direction.
    Type: Application
    Filed: June 19, 2009
    Publication date: May 5, 2011
    Applicant: THE YOKOHAMA RUBBER CO., LTD.
    Inventor: Takahiro Yamakawa
  • Patent number: 7781359
    Abstract: There is provided a high-frequency dielectric material that has a high relative permittivity, a high Q value, and a TCF property value close to zero (0) and can realize co-firing of the dielectric material with silver (Ag) and copper (Cu). The high-frequency dielectric material is characterized by comprising a composition of main constituent materials having a formulation of CaO: 1 mole, Nb2O5: (1??×?)/3 mole, ZnO: (1??)/3 mole, TiO2: ? mole, and Li2O: ?×(1??)/6 mole, wherein 0.65???0.75, 0.09???0.15, 0.066??×??0.100, and 0.15???0.35; and 1 to 5 parts by weight, based on 100 parts by weight of the composition of main constituent materials, of a sintering aid selected from the group consisting of oxides of copper (Cu), boron (B), lithium (Li), bismuth (Bi), and vanadium (V) and a mixture of two or more of the oxides.
    Type: Grant
    Filed: April 16, 2007
    Date of Patent: August 24, 2010
    Assignee: Yokowo Co., Ltd.
    Inventors: Takahiro Yamakawa, Shi Luo
  • Publication number: 20100116392
    Abstract: A pneumatic tire includes a pair of first circumferential main grooves formed in the center region of a tread, a pair of second circumferential main grooves formed respectively outward of the corresponding first main grooves, a plurality of first lug grooves which each extend from one of the two shoulder ends of the tread inward in the tire-width direction and communicate with the corresponding first main groove, a plurality of second lug grooves alternately arranged in the tire circumferential direction which each extend from one of the two shoulder ends of the tread inward in the tire-width direction but do not communicate with the corresponding first main groove, a center rib defined between the pair of first main grooves and extends continuously in the tire circumferential direction, a shoulder block row defined between each of the second main grooves and a corresponding one of the shoulder ends and includes a plurality of blocks, and an intermediate block row defined between each of the first main groove
    Type: Application
    Filed: June 9, 2008
    Publication date: May 13, 2010
    Applicant: THE YOKOHAMA RUBBER CO., LTD.
    Inventor: Takahiro Yamakawa
  • Patent number: D595219
    Type: Grant
    Filed: December 9, 2008
    Date of Patent: June 30, 2009
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Takahiro Yamakawa, Takumi Morito
  • Patent number: D707621
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: June 24, 2014
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Hiroshi Tokizaki, Takahiro Yamakawa
  • Patent number: D712819
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: September 9, 2014
    Assignee: The Yokohama Rubber Co., Ltd.
    Inventors: Takahiro Yamakawa, Hiroshi Tokizaki