Patents by Inventor Akiyoshi Shimizu

Akiyoshi Shimizu 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: 11919335
    Abstract: A pneumatic tire of the present disclosure includes, on a tread surface, a plurality of circumferential main grooves extending in the tire circumferential direction, and a plurality of land portions defined between circumferential main grooves adjacent in the tire width direction among the plurality of circumferential main grooves or by the circumferential main grooves and tread edges. The land portions include at least one circumferential sipe extending in the tire circumferential direction. The circumferential sipe includes a plurality of widened portions arranged in the tire circumferential direction. In a reference state, each widened portion is formed only from a portion that, from one side towards the other side in the tire circumferential direction, extends from the tread surface inward in the tire radial direction.
    Type: Grant
    Filed: June 22, 2020
    Date of Patent: March 5, 2024
    Assignee: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi Shimizu
  • Patent number: 11904636
    Abstract: A pneumatic tire includes, in a land portion, at least one circumferential sipe extending in the tire circumferential direction. At a first position, from the tread surface towards the sipe bottom, the sipe width gradually decreases from the tread surface to a first changing point and then gradually increases from the first changing point to the sipe bottom. At a second position, from the tread surface towards the sipe bottom, the sipe width gradually increases from the tread surface to a second changing point and then gradually decreases from the second changing point to the sipe bottom. The sipe width at the tread surface and at the sipe bottom gradually decreases in the tire circumferential direction from the first position towards the second position, and the sipe width in a tire radial intermediate portion gradually increases in the tire circumferential direction from the first position towards the second position.
    Type: Grant
    Filed: June 22, 2020
    Date of Patent: February 20, 2024
    Assignee: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi Shimizu
  • Publication number: 20220371377
    Abstract: A pneumatic tire of the present disclosure includes, on a tread surface, a plurality of circumferential main grooves extending in the tire circumferential direction, and a plurality of land portions defined between circumferential main grooves adjacent in the tire width direction among the plurality of circumferential main grooves or by the circumferential main grooves and tread edges. The land portions include at least one circumferential sipe extending in the tire circumferential direction. The circumferential sipe includes a plurality of widened portions arranged in the tire circumferential direction. In a reference state, each widened portion is formed only from a portion that, from one side towards the other side in the tire circumferential direction, extends from the tread surface inward in the tire radial direction.
    Type: Application
    Filed: June 22, 2020
    Publication date: November 24, 2022
    Applicant: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi SHIMIZU
  • Publication number: 20220332147
    Abstract: A pneumatic tire includes, on a tread surface, circumferential main grooves extending in the tread circumferential direction, and land portions defined between circumferential main grooves adjacent in a tread width direction among the circumferential main grooves or by the circumferential main grooves and tread edges. The land portions include widthwise sipes (or grooves) extending in the tread width direction, and each widthwise sipe (or groove) includes a tread surface side sipe (or groove) portion extending from the tread surface inward in a tire radial direction, a first branched sipe (or groove) portion branching and extending from the tread surface side sipe (or groove) portion inward in the tire radial direction, and second branched sipe (or groove) portions branching and extending from respective tire radial inner ends of the first branched sipe (or groove) portion inward in the tire radial direction.
    Type: Application
    Filed: June 22, 2020
    Publication date: October 20, 2022
    Applicant: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi SHIMIZU
  • Publication number: 20220324264
    Abstract: A pneumatic tire includes, in a land portion, at least one circumferential sipe extending in the tire circumferential direction. At a first position, from the tread surface towards the sipe bottom, the sipe width gradually decreases from the tread surface to a first changing point and then gradually increases from the first changing point to the sipe bottom. At a second position, from the tread surface towards the sipe bottom, the sipe width gradually increases from the tread surface to a second changing point and then gradually decreases from the second changing point to the sipe bottom. The sipe width at the tread surface and at the sipe bottom gradually decreases in the tire circumferential direction from the first position towards the second position, and the sipe width in a tire radial intermediate portion gradually increases in the tire circumferential direction from the first position towards the second position.
    Type: Application
    Filed: June 22, 2020
    Publication date: October 13, 2022
    Applicant: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi SHIMIZU
  • Patent number: 9308779
    Abstract: An object of the present invention is to provide a tire possessing improved partial wear resistance by optimizing shapes and dimensions of a block land portion and its position and arrangement. The tire has plural block land portion arrays 5 formed by a large number of block land portions 4 defined on a tread portion 1. Between two block land portion arrays 5 located adjacent to each other across the circumferential groove 2, the block land portions 4 constituting the block land portion arrays 5 are arranged on the tread portion 1 so as to be positionally displaced from each other in the circumferential direction of the tire; a groove 6 between the block land portions adjacent to each other in the width direction of the tire extends obliquely with respect to the width and circumferential directions of the tire.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: April 12, 2016
    Assignee: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi Shimizu
  • Patent number: 9186936
    Abstract: An object of the present invention is to provide a tire possessing improved wear resistance by optimizing configurations of block land portions. The tire is configured such that, in at least two adjacent block land portion arrays 5 sandwiching a circumferential groove 2, adjacent block land portions 4 constituting the block land portion arrays 5 are arranged so as to be positionally displaced from each other in the tire circumferential direction; and a distance d2 between the block land portions adjacent in the tire width direction is shorter than a distance d1 between the block land portions adjacent in the tire circumferential direction. A groove portion 8 between the block land portions adjacent in the tire width direction extends obliquely with respect to the tire width direction and the tire circumferential direction.
    Type: Grant
    Filed: August 12, 2009
    Date of Patent: November 17, 2015
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Nagakazu Kuwahara, Akiyoshi Shimizu
  • Patent number: 9139049
    Abstract: An object the present invention is to provide a tire having a rib-like land portion and sipes provided therein, in which wear resistance has been enhanced by optimizing the shape of the sipes, while good fraction performance on a wet road surface is maintained. The tire has, in a tread portion, at least one row of rib-like land portion and sipes provided in the rib-like land portion. Further, depth of each sipe at least at one end portion thereof on the shoulder side is smaller than depth of the sipe at the remaining portions thereof.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: September 22, 2015
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Akira Nakamizo, Akiyoshi Shimizu
  • Patent number: 9073391
    Abstract: Provided is a tire exhibiting both improved partial wear resistance and improved quietness. The tire has block land portion arrays 5 defined on a tread portion 1. Between adjacent two block land portion arrays 5 sandwiching a circumferential groove 2, block land portions 4 constituting the block land portions 5 are arranged so as to be positionally displaced from each other in the tire circumferential direction, and a groove portion 6 between the block land portions adjacent in the tire width direction extends obliquely with respect to the tire width direction and the tire circumferential direction.
    Type: Grant
    Filed: November 27, 2009
    Date of Patent: July 7, 2015
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Akira Nakamizo, Akiyoshi Shimizu
  • Patent number: 8863796
    Abstract: Provided is a tire exhibiting improved wear resistance, partial wear resistance, and traction performance on the wet road surface. The tire has block land portion arrays 5 defined on a tread portion 1. Between two block land portion arrays 5 located adjacent to each other while sandwiching a circumferential groove 2, a block land portions 4 constituting the block land portion arrays are arrange so as to be positionally displaced from each other, and a groove portion 6 located between the block land portions adjacent in the tire width direction extends obliquely with respect to tire width direction and the tire circumferential direction. At this time, a distance d2 between the block land portions adjacent in the tire width direction is shorter than a distance d1 between the block land portions adjacent in the circumferential direction.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: October 21, 2014
    Assignee: Bridgestone Corporation
    Inventors: Akira Nakamizo, Akiyoshi Shimizu
  • Patent number: 8851130
    Abstract: An object the present invention is to provide a tire, in which wear resistance has been enhanced by optimizing the shape and location of block land portions. The tire has plural rows 5 of block land portions 4 formed by demarcation by providing plural circumferential grooves 2 extending along tire circumferential direction and plural lateral grooves 3 for communicating adjacent two circumferential grooves 2,2 with each other; in at least two rows 5 of block land portions adjacent to each other with a circumferential groove therebetween, among the rows 5 of block land portions 4, the respective rows 5 of block land portions 4 are disposed to be offset with respect to each other in the tire circumferential direction. The extending direction of the groove portion 6 between the block land portions adjacent to each other in the tire widthwise direction is inclined with respect to the tire widthwise direction and tire circumferential direction.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: October 7, 2014
    Assignee: Bridgestone Corporation
    Inventor: Akiyoshi Shimizu
  • Patent number: 8800618
    Abstract: A component Fin toward an axial inner direction of the tire which is an opposite direction from an axial outer direction of the tire is applied to a force acting on a kicking end 16B of a land portion 16. With this, abrasion of the kicking end of the land portion can be moderated, and a biased abrasion resistance can be enhanced. A groove wall 20 of a lug groove 14 is provided with a step portion 22, a tread side groove width WA in a tread side of the step portion is widened toward an axial outer side of the tire, and a width WS of the step portion 22 is increased toward the axial outer side of the tire, thereby suppressing the lift from the road surface 26 at the tread-in end 16A of the land portion 16.
    Type: Grant
    Filed: January 11, 2006
    Date of Patent: August 12, 2014
    Assignee: Bridgestone Corporation
    Inventor: Akiyoshi Shimizu
  • Patent number: 8191591
    Abstract: A pneumatic tire maintaining excellent traction performance for the entire life of the tire. The tire (10) has blocks (18) each demarcated by both a circumferential groove formed in the tread and lateral grooves crossing the circumferential groove, and also has recessed parts (20). Each recessed part (20) is formed in at least one of those both wall surfaces of each block (18) that are oriented to the lateral direction of the tire, and the circumferential width (C) of each recessed part (20) is increased from the tread side of the block (18) toward the radially inside of the tire. Because the edge effect of the blocks (18) at the portions between the lateral grooves and the recessed parts (20) can be maintained in an excellent state even if the wear of the tire (10) progresses, the edge effect of the entire blocks can be maintained in an excellent state, and excellent traction performance can be maintained for the entire life of the tire.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: June 5, 2012
    Assignee: Bridgestone Corporation
    Inventor: Akiyoshi Shimizu
  • Publication number: 20110232815
    Abstract: Provided is a tire exhibiting improved wear resistance, partial wear resistance, and traction performance on the wet road surface. The tire has block land portion arrays 5 defined on a tread portion 1. Between two block land portion arrays 5 located adjacent to each other while sandwiching a circumferential groove 2, a block land portions 4 constituting the block land portion arrays are arrange so as to be positionally displaced from each other, and a groove portion 6 located between the block land portions adjacent in the tire width direction extends obliquely with respect to tire width direction and the tire circumferential direction. At this time, a distance d2 between the block land portions adjacent in the tire width direction is shorter than a distance d1 between the block land portions adjacent in the circumferential direction.
    Type: Application
    Filed: November 10, 2009
    Publication date: September 29, 2011
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Akira Nakamizo, Akiyoshi Shimizu
  • Publication number: 20110232814
    Abstract: Provided is a tire exhibiting both improved partial wear resistance and improved quietness. The tire has block land portion arrays 5 defined on a tread portion 1. Between adjacent two block land portion arrays 5 sandwiching a circumferential groove 2, block land portions 4 constituting the block land portions 5 are arranged so as to be positionally displaced from each other in the tire circumferential direction, and a groove portion 6 between the block land portions adjacent in the tire width direction extends obliquely with respect to the tire width direction and the tire circumferential direction.
    Type: Application
    Filed: November 27, 2009
    Publication date: September 29, 2011
    Applicant: Bridgestone Corporation
    Inventors: Akira Nakamizo, Akiyoshi Shimizu
  • Publication number: 20110139324
    Abstract: An object of the present invention is to provide a tire possessing improved wear resistance by optimizing configurations of block land portions. The tire is configured such that, in at least two adjacent block land portion arrays 5 sandwiching a circumferential groove 2, adjacent block land portions 4 constituting the block land portion arrays 5 are arranged so as to be positionally displaced from each other in the tire circumferential direction; and a distance d2 between the block land portions adjacent in the tire width direction is shorter than a distance d1 between the block land portions adjacent in the tire circumferential direction. A groove portion 8 between the block land portions adjacent in the tire width direction extends obliquely with respect to the tire width direction and the tire circumferential direction.
    Type: Application
    Filed: August 12, 2009
    Publication date: June 16, 2011
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Nagakazu KUWAHARA, Akiyoshi Shimizu
  • Publication number: 20110108176
    Abstract: An object the present invention is to provide a tire having a rib-like land portion and sipes provided therein, in which wear resistance has been enhanced by optimizing the shape of the sipes, while good fraction performance on a wet road surface is maintained. The tire has, in a tread portion, at least one row of rib-like land portion and sipes provided in the rib-like land portion. Further, depth of each sipe at least at one end portion thereof on the shoulder side is smaller than depth of the sipe at the remaining portions thereof.
    Type: Application
    Filed: June 18, 2009
    Publication date: May 12, 2011
    Applicant: Bridgestone Corporation
    Inventors: Akira Nakamizo, Akiyoshi Shimizu
  • Publication number: 20110100520
    Abstract: An object of the present invention is to provide a tire possessing improved partial wear resistance by optimizing shapes and dimensions of a block land portion and its position and arrangement. The tire has plural block land portion arrays 5 formed by a large number of block land portions 4 defined on a tread portion 1. Between two block land portion arrays 5 located adjacent to each other across the circumferential groove 2, the block land portions 4 constituting the block land portion arrays 5 are arranged on the tread portion 1 so as to be positionally displaced from each other in the circumferential direction of the tire; a groove 6 between the block land portions adjacent to each other in the width direction of the tire extends obliquely with respect to the width and circumferential directions of the tire.
    Type: Application
    Filed: May 27, 2009
    Publication date: May 5, 2011
    Applicant: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi Shimizu
  • Publication number: 20100180997
    Abstract: An object the present invention is to provide a tire, in which wear resistance has been enhanced by optimizing the shape and location of block land portions. The tire has plural rows 5 of block land portions 4 formed by demarcation by providing plural circumferential grooves 2 extending along tire circumferential direction and plural lateral grooves 3 for communicating adjacent two circumferential grooves 2,2 with each other; in at least two rows 5 of block land portions adjacent to each other with a circumferential groove therebetween, among the rows 5 of block land portions 4, the respective rows 5 of block land portions 4 are disposed to be offset with respect to each other in the tire circumferential direction. The extending direction of the groove portion 6 between the block land portions adjacent to each other in the tire widthwise direction is inclined with respect to the tire widthwise direction and tire circumferential direction.
    Type: Application
    Filed: May 28, 2008
    Publication date: July 22, 2010
    Applicant: BRIDGESTONE CORPORATION
    Inventor: Akiyoshi Shimizu
  • Patent number: D669419
    Type: Grant
    Filed: February 10, 2011
    Date of Patent: October 23, 2012
    Assignee: Bridgestone Corporation
    Inventor: Akiyoshi Shimizu