Patents by Inventor Yasuaki Fujita

Yasuaki Fujita 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: 8083297
    Abstract: The present invention relates to a coreless rubber crawler traveling device in which spring characteristics are achieved by reducing a contact area of a wheel-rolling contact surface on an inner peripheral surface of a rubber elastic body with an outer surface of a tracker roller. A coreless rubber crawler comprises an endless rubber elastic body, main cord rows embedded in the rubber elastic body in a longitudinal direction of the rubber elastic body, rubber projections formed on the inner peripheral surface of the rubber elastic body at uniform pitches, and rubber lugs formed on the outer peripheral surface of the rubber elastic body. In the coreless rubber crawler traveling device, a tracker roller, which is provided at the side of a vehicle body and which straddles the right and left sides of each of the rubber projections in the widthwise direction, rolls in such a manner that an outer surface of the tracker roller comes into contact with the inner peripheral surface of the rubber elastic body.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: December 27, 2011
    Assignee: Bridgestone Corporation
    Inventor: Yasuaki Fujita
  • Patent number: 7695077
    Abstract: To improve the lifespan of a rubber crawler by reducing as much as possible cracks due to bending at the time of wraparound. Bending deformation no longer becomes concentrated at a specific place because bending rigidities at the time of wraparound are not so different from each other overall. For that reason, the occurrence of cracks can be reduced. As a result, the lifespan of the rubber crawler is improved.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: April 13, 2010
    Assignee: Bridgestone Corporation
    Inventor: Yasuaki Fujita
  • Patent number: 7325888
    Abstract: A rubber crawler having a very good straight driving property is obtained by modifying a method of embedding bias cords in a rubber crawler and neutralizing shear stresses caused by tensile load of bent portions of the crawler when the crawler is entrained about a vehicle main body. The rubber crawler is comprised of an endless rubber elastic body, a main cord row, two layers of bias cords having opposite angles of inclination, guide projections, and a lug. The bias cords of the first layer at a side near the main cord row are embedded over a region having substantially the same transverse dimension as that of the main cord row, at a fixed angle of inclination, and the bias cords of the second layer are divided into two sections, covering a region having substantially the same transverse dimension as that of the bias cords of the first layer other than a portions corresponding to the guide projections.
    Type: Grant
    Filed: May 27, 2004
    Date of Patent: February 5, 2008
    Assignee: Bridgestone Corporation
    Inventors: Yasuaki Fujita, Shuichi Matsuo
  • Publication number: 20080007118
    Abstract: To improve the lifespan of a rubber crawler by reducing as much as possible cracks due to bending at the time of wraparound. Bending deformation no longer becomes concentrated at a specific place because bending rigidities at the time of wraparound are not so different from each other overall. For that reason, the occurrence of cracks can be reduced. As a result, the lifespan of the rubber crawler is improved.
    Type: Application
    Filed: December 2, 2005
    Publication date: January 10, 2008
    Applicant: Bridgestone Corporation
    Inventor: Yasuaki Fujita
  • Publication number: 20070252433
    Abstract: The present invention relates to a coreless rubber crawler traveling device in which spring characteristics are achieved by reducing a contact area of a wheel-rolling contact surface on an inner peripheral surface of a rubber elastic body with an outer surface of a tracker roller. A coreless rubber crawler comprises an endless rubber elastic body, main cord rows embedded in the rubber elastic body in a longitudinal direction of the rubber elastic body, rubber projections formed on the inner peripheral surface of the rubber elastic body at uniform pitches, and rubber lugs formed on the outer peripheral surface of the rubber elastic body. In the coreless rubber crawler traveling device, a tracker roller, which is provided at the side of a vehicle body and which straddles the right and left sides of each of the rubber projections in the widthwise direction, rolls in such a manner that an outer surface of the tracker roller comes into contact with the inner peripheral surface of the rubber elastic body.
    Type: Application
    Filed: January 28, 2005
    Publication date: November 1, 2007
    Inventor: Yasuaki Fujita
  • Publication number: 20060232129
    Abstract: A rubber crawler having a very good straight driving property is obtained by modifying a method of embedding bias cords in a rubber crawler and neutralizing shear stresses caused by tensile load of bent portions of the crawler when the crawler is entrained about a vehicle main body. The rubber crawler is comprised of an endless rubber elastic body, a main cord row, two layers of bias cords having opposite angles of inclination, guide projections, and a lug. The bias cords of the first layer at a side near the main cord row are embedded over a region having substantially the same transverse dimension as that of the main cord row, at a fixed angle of inclination, and the bias cords of the second layer are divided into two sections, covering a region having substantially the same transverse dimension as that of the bias cords of the first layer other than a portions corresponding to the guide projections.
    Type: Application
    Filed: May 27, 2004
    Publication date: October 19, 2006
    Inventors: Yasuaki Fujita, Shuichi Matsuo
  • Patent number: 6818167
    Abstract: In a method of manufacturing a rubber crawler through a first vulcanization step and a second vulcanization step using an upper mold, a middle mold and a lower mold, at least the middle mold is heated at each vulcanization step, and a vulcanizing circumferential length at the first vulcanization step is made longer than that at the second vulcanization step, and the second vulcanization step is carried out at a state that each end portion of the crawler part formed at the first vulcanization step is positioned by at least one pitch rate in each mold at the second vulcanization step and the distance between the upper and lower molds is made larger than that in the first vulcanization step.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: November 16, 2004
    Assignee: Bridgestone Corporation
    Inventor: Yasuaki Fujita
  • Patent number: 6767493
    Abstract: It is to provide a method of manufacturing a rubber crawler which enhances a degree of freedom in the handling in a vulcanization-shaping of a crawler part and largely improves vulcanization shapability and operability and facilitates an arrangement of an auxiliary device or the like.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: July 27, 2004
    Assignee: Bridgestone Corporation
    Inventor: Yasuaki Fujita
  • Publication number: 20030168777
    Abstract: In a method of manufacturing a rubber crawler through a first vulcanization step and a second vulcanization step using an upper mold, a middle mold and a lower mold, at least the middle mold is heated at each vulcanization step, and a vulcanizing circumferential length at the first vulcanization step is made longer than that at the second vulcanization step, and the second vulcanization step is carried out at a state that each end portion of the crawler part formed at the first vulcanization step is positioned by at least one pitch rate in each mold at the second vulcanization step and the distance between the upper and lower molds is made larger than that in the first vulcanization step.
    Type: Application
    Filed: March 26, 2003
    Publication date: September 11, 2003
    Applicant: BRIDGESTONE CORPORATION
    Inventor: Yasuaki Fujita
  • Publication number: 20030141630
    Abstract: It is to provide a method of manufacturing a rubber crawler which enhances a degree of freedom in the handling in a vulcanization-shaping of a crawler part and largely improves vulcanization shapability and operability and facilitates an arrangement of an auxiliary device or the like.
    Type: Application
    Filed: November 8, 2002
    Publication date: July 31, 2003
    Inventor: Yasuaki Fujita
  • Patent number: D514133
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: January 31, 2006
    Assignee: Bridgestone Corporation
    Inventor: Yasuaki Fujita