Patents by Inventor Yukio Nawa

Yukio Nawa 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: 8555735
    Abstract: The starter includes an electromagnetic switch includes a first solenoid for pushing out the pinion shaft to an engine side and a second solenoid for opening and closing a main contact through which a current is supplied to a motor. The first and second solenoids are disposed coaxially with the pinion shaft. The first and second plungers included in the first and second solenoids, respectively are disposed overlapping with each other in the axial direction of the starter such that a rear portion of the first plunger enters inside the second plunger when they are deenergized.
    Type: Grant
    Filed: April 16, 2012
    Date of Patent: October 15, 2013
    Assignee: Denso Corporation
    Inventors: Yukio Nawa, Youichi Hasegawa
  • Patent number: 8390408
    Abstract: In an electromagnetic switch, current flow through a coil causes a plunger to be axially displaced by magnetic attraction, against a restoring force of a return spring, thereby axially displacing a movable contact against fixed contacts and so enabling current flow via the contacts. One or more contact displacement limiting members are disposed on the opposite side of the fixed contacts from the movable contact, for limiting the extent to which the movable contact can be axially displaced when the fixed contacts have become worn by repetitive switching operations. A condition in which the movable contact cannot be restored to a “contacts open” position is thereby prevented.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: March 5, 2013
    Assignee: Denso Corporation
    Inventor: Yukio Nawa
  • Publication number: 20120260770
    Abstract: The starter includes an electromagnetic switch includes a first solenoid for pushing out the pinion shaft to an engine side and a second solenoid for opening and closing a main contact through which a current is supplied to a motor. The first and second solenoids are disposed coaxially with the pinion shaft. The first and second plungers included in the first and second solenoids, respectively are disposed overlapping with each other in the axial direction of the starter such that a rear portion of the first plunger enters inside the second plunger when they are deenergized.
    Type: Application
    Filed: April 16, 2012
    Publication date: October 18, 2012
    Applicant: DENSO CORPORATION
    Inventors: Yukio NAWA, Youichi HASEGAWA
  • Publication number: 20120242431
    Abstract: In an electromagnetic switch, current flow through a coil causes a plunger to be axially displaced by magnetic attraction, against a restoring force of a return spring, thereby axially displacing a movable contact against fixed contacts and so enabling current flow via the contacts. One or more contact displacement limiting members are disposed on the opposite side of the fixed contacts from the movable contact, for limiting the extent to which the movable contact can be axially displaced when the fixed contacts have become worn by repetitive switching operations. A condition in which the movable contact cannot be restored to a “contacts open” position is thereby prevented.
    Type: Application
    Filed: March 23, 2012
    Publication date: September 27, 2012
    Applicant: DENSO CORPORATION
    Inventor: Yukio NAWA
  • Patent number: 7870801
    Abstract: A rotational power transfer device and a method of manufacturing the same are provided. The rotational power transfer device includes a first rotary member and a second rotary member. The first rotary member has an inner periphery formed with a solid lubricating layer composed of a chemical film and molybdenum disulfide. The second rotary member has an outer cylindrical periphery applied with a layer of grease including a mixture of oil with a higher frictional coefficient than that of lubricating oil and molybdenum disulfide. The second rotary member is press fitted to the first rotary member to allow the outer cylindrical periphery thereof to be placed in face-to-face relation to the inner cylindrical periphery of the first rotary member, enabling a rotational power in excess to be stably absorbed without causing any increase in the rotational power at which the slippage occurs.
    Type: Grant
    Filed: June 8, 2007
    Date of Patent: January 18, 2011
    Assignee: Denso Corporation
    Inventors: Yukio Nawa, Mitsukazu Hattori, Yoshinori Yamaguchi
  • Patent number: 7677123
    Abstract: An impact absorbing device has fixed discs and rotary discs alternately and coaxially disposed. Each disc has two surfaces, and two surfaces of each pair of fixed and rotary discs face each other through a lubricant. Each surface has dimples, respectively, surrounded by concave portions. A position of each dimple in the rotary discs is differentiated from a position of any dimple of the fixed discs in a radial direction of the discs. In response to an impact given to the rotary discs, the rotary discs are rotated on the fixed discs against a frictional force between the discs to absorb the impact. During this rotation, each dimple of the rotary discs is moved along a circumferential direction of the discs, and no concave portions of the rotary discs are placed just on the concave portions of the fixed discs.
    Type: Grant
    Filed: September 17, 2007
    Date of Patent: March 16, 2010
    Assignee: Denso Corporation
    Inventor: Yukio Nawa
  • Publication number: 20080196544
    Abstract: A starter for cranking an internal combustion engine includes a device for absorbing a rotational torque exceeding a predetermined level. In this device, a laminated body composed of fixed disks and the rotatable disks is used. A frictional force in the laminated body is preset by a spring member pressing the laminated body in the laminated direction. To avoid concentration of the pressing force to a position where the spring force is imposed, a certain gap is formed between the spring member and the laminated body. To give a proper surface hardness to an internal gear portion of the rotatable disk and to give an abrasion-resistive property to a portion contacting the fixed disk, the rotatable disk is subjected to soft nitriding treatment. Thus, a stable frictional force is secured in the laminated body, and a long life of the excessive-torque-absorbing device is realized.
    Type: Application
    Filed: October 12, 2007
    Publication date: August 21, 2008
    Applicant: DENSO CORPORATION
    Inventors: Sadayoshi Kajino, Yukio Nawa
  • Publication number: 20080087134
    Abstract: An impact absorbing device has fixed discs and rotary discs alternately and coaxially disposed. Each disc has two surfaces, and two surfaces of each pair of fixed and rotary discs face each other through a lubricant. Each surface has dimples, respectively, surrounded by concave portions. A position of each dimple in the rotary discs is differentiated from a position of any dimple of the fixed discs in a radial direction of the discs. In response to an impact given to the rotary discs, the rotary discs are rotated on the fixed discs against a frictional force between the discs to absorb the impact. During this rotation, each dimple of the rotary discs is moved along a circumferential direction of the discs, and no concave portions of the rotary discs are placed just on the concave portions of the fixed discs.
    Type: Application
    Filed: September 17, 2007
    Publication date: April 17, 2008
    Applicant: DENSO CORPORATION
    Inventor: Yukio Nawa
  • Publication number: 20080006104
    Abstract: A rotational power transfer device and a method of manufacturing the same are provided. The rotational power transfer device includes a first rotary member and a second rotary member. The first rotary member has an inner periphery formed with a solid lubricating layer composed of a chemical film and molybdenum disulfide. The second rotary member has an outer cylindrical periphery applied with a layer of grease including a mixture of oil with a higher frictional coefficient than that of lubricating oil and molybdenum disulfide. The second rotary member is press fitted to the first rotary member to allow the outer cylindrical periphery thereof to be placed in face-to-face relation to the inner cylindrical periphery of the first rotary member, enabling a rotational power in excess to be stably absorbed without causing any increase in the rotational power at which the slippage occurs.
    Type: Application
    Filed: June 8, 2007
    Publication date: January 10, 2008
    Applicant: DENSO CORPORATION
    Inventors: Yukio Nawa, Mitsukazu Hattori, Yoshinori Yamaguchi
  • Publication number: 20060144175
    Abstract: A starter for automotive engines is provided which is equipped with a planetary gear speed reducer and a torque impact absorber. The torque impact absorber is made up of an outer cylindrical shell and an internal gear of a planetary gear train. The outer cylindrical shell has formed thereon a plurality of lock protrusions which are fitted in a starter casing to keep the outer cylindrical shell from rotating. The protrusions extend in an axial direction of the starter, thus permitting the size of the starter to be decreased.
    Type: Application
    Filed: December 19, 2005
    Publication date: July 6, 2006
    Applicant: DENSO CORPORATION
    Inventors: Yukio Nawa, Sadayoshi Kajino, Youichi Hasegawa