Patents by Inventor Kouhei Yonezawa

Kouhei Yonezawa 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: 7886630
    Abstract: When a column 4 reaches a tilting ascent end, the lower end 732 of a nut 73 abuts on the buffering segment 83 of a buffer 82. Thus, while the buffering segment 83 of the buffer 82 is elastically deformed, the nut 73 stops with no impact. Accordingly, the inertia when the nut 73 stops is restrained and the tightening torque of the nut 73 when the nut 73 stops is also restrained. For this reason, when an electric motor 61 is rotationally driven in a reverse direction, a feeding screw shaft 71 rotates in the reverse direction with the normal rotation torque of the electric motor 61. Thus, the nut 73 is caused to ascend in the axial direction along the screw segment of the feeding screw shaft 71 so that the column 4 can be tiltingly moved downward.
    Type: Grant
    Filed: February 8, 2007
    Date of Patent: February 15, 2011
    Assignee: NSK Ltd.
    Inventors: Masaki Tomaru, Yuuichi Tomaru, Kouhei Yonezawa, Naoki Sawada
  • Publication number: 20090308189
    Abstract: Provided are a steering device and a feed screw mechanism. The steering device is made so easy in the adjusting work of a backlash that it can eliminate the backlash reliably, even if the precision of the thread of a feed thread shaft or a feed nut is poor, thereby to improve the rigidity and to reduce the manufacturing cost of the feed screw mechanism. An upper-side end portion feed nut is urged upward of FIG. 8 by an upper-side disc spring so that an upper-side flank face of the thread ridge of the upper-side end portion fee nut is brought into close contact with the lower-side flank face of the thread ridge of a feed screw shaft. On the other hand, a lower-side end portion feed nut is urged downward of FIG. 8 by a lower-side disc spring so that a lower-side flank face of the thread ridge of the lower-side end portion fee nut is brought into close contact with the upper-side flank face of the thread ridge of the feed screw shaft.
    Type: Application
    Filed: June 25, 2007
    Publication date: December 17, 2009
    Applicant: NSK Ltd.
    Inventors: Masaki Tomaru, Yuichi Tomaru, Kouhei Yonezawa, Takahiro Minamigata, Koji Nagai
  • Publication number: 20080156138
    Abstract: When a lower column 3 tilts upwards or downwards, a vehicular front end face 831 of a resin cover 83 having a small friction coefficient tilts slidably along a first guide surface 22A of a left-hand side plate 22 of a vehicle body mounting upper bracket 2. Consequently, since there emerges no situation in which the front end face 831 is caught on the first guide surface 22A of the left-hand side plate of the vehicle body mounting upper bracket 2, a smooth tilt position adjustment can be implemented without any abnormal noise. Further, in secondary collision, the front end face 831 of the resin cover 83 collides with the first guide surface 22A of the left-hand side plate 22 of the vehicle body mounting upper bracket 2, whereby frontward impact force can be transmitted to the vehicle body mounting upper bracket 2 in an ensured fashion.
    Type: Application
    Filed: December 18, 2007
    Publication date: July 3, 2008
    Applicant: NSK LTD.
    Inventors: Masaki TOMARU, Kouji NAGAI, Kouhei YONEZAWA
  • Publication number: 20080047382
    Abstract: In the steering apparatus and feed screw mechanism, by properly adjusting the screw-in distance of a pressing force adjusting screw 77, the arc-shaped contact surface 761 of a pressing member 76 can be pressed against the outer diameter portion 711 of a feed screw shaft 71 with a required pressing force due to the biasing force of a compression coil spring 78. As a result of this, a backlash between a feed nut 73 and feed screw shaft 71 can be removed. Therefore, the telescopic position adjustment and tilt position adjustment of a steering wheel 3 can be carried out smoothly, thereby being able to enhance the rigidity of the steering wheel 3 after execution of the position adjustment thereof.
    Type: Application
    Filed: August 23, 2007
    Publication date: February 28, 2008
    Applicant: NSK LTD.
    Inventors: Masaki Tomaru, Kouhei Yonezawa, Hiroyuki Muramatsu
  • Publication number: 20070180945
    Abstract: When a column 4 reaches a tilting ascent end, the lower end 732 of a nut 73 abuts on the buffering segment 83 of a buffer 82. Thus, while the buffering segment 83 of the buffer 82 is elastically deformed, the nut 73 stops with no impact. Accordingly, the inertia when the nut 73 stops is restrained and the tightening torque of the nut 73 when the nut 73 stops is also restrained. For this reason, when an electric motor 61 is rotationally driven in a reverse direction, a feeding screw shaft 71 rotates in the reverse direction with the normal rotation torque of the electric motor 61. Thus, the nut 73 is caused to ascend in the axial direction along the screw segment of the feeding screw shaft 71 so that the column 4 can be tiltingly moved downward.
    Type: Application
    Filed: February 8, 2007
    Publication date: August 9, 2007
    Applicant: NSK LTD.
    Inventors: Masaki Tomaru, Yuuichi Tomaru, Kouhei Yonezawa, Naoki Sawada