Patents by Inventor Yoshifumi Kurokawa

Yoshifumi Kurokawa 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: 10717459
    Abstract: A portion of the target guide plate interposed between the rolling surface of each ball and an inner surface of the sub-concave groove is supported at the other radial surface opposite to the rolling surface of each ball by the inner surface of the sub-concave groove at a state where one radial surface facing towards the rolling surface of each ball is pressed by the rolling surface of each ball and is thus curved along the rolling surface of each ball.
    Type: Grant
    Filed: July 26, 2016
    Date of Patent: July 21, 2020
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa
  • Publication number: 20200094866
    Abstract: A steering apparatus having inner and outer columns. The outer column is made of an extrusion molded product, and includes a pair of side plate sections respectively extending in the axial direction, located on both sides in the width direction of the inner column, and has a column-side through hole that passes through in the width direction on one side than the inner column with respect to the height direction in a part in the axial direction thereof, and a column pressing section is provided in at least one of the pair of plate sections and able to press the inner column in a direction away from the column-side through holes with respect to the height direction when displaced inward in the width direction, and a widening section in at least one of the pair of plate sections and pressed outward in the width direction via the inner column that is pressed by the column pressing sections.
    Type: Application
    Filed: June 8, 2018
    Publication date: March 26, 2020
    Inventor: Yoshifumi Kurokawa
  • Patent number: 10597065
    Abstract: In a clamped state where the interval between both the pressing parts is reduced and both the clamped plate parts are clamped by both the support plate parts, vertical distances from an outer peripheral surface of the adjustment rod to an upper surface and a lower surface of an inner surface of one through-hole of both the through-holes are different, vertical distances from the outer peripheral surface of the adjustment rod to an upper surface and a lower surface of an inner surface of the other through-hole of both the through-holes are different, and sides, where the vertical distance from the outer peripheral surface of the adjustment rod to the inner surface is smaller, are on opposite sides with respect to the vertical direction in one through-hole and the other through-hole.
    Type: Grant
    Filed: December 2, 2016
    Date of Patent: March 24, 2020
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa
  • Patent number: 10597064
    Abstract: Non-circular portions (41) are provided in two positions of an adjusting rod (17a) in an axial direction, and the non-circular portions (41) are disposed inside of telescopic-adjusting long holes (16a) of a displacement bracket (13a). Up-down-direction clearances (44a and 44b) which are present between opposite edges of each of the non-circular portions (41) in an up-down direction and inner surfaces of each of the telescopic-adjusting long holes (16a) in the up-down direction in a state where a position of a steering wheel can be maintained are less than up-down-direction clearances (43a and 43b) which are present between the opposite edges of each of the non-circular portions (41) in the up-down direction and the inner surfaces of each of the telescopic-adjusting long holes (16a) in the up-down direction in a state where the position of the steering wheel can be adjusted.
    Type: Grant
    Filed: October 26, 2016
    Date of Patent: March 24, 2020
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa
  • Publication number: 20190300041
    Abstract: Reinforcing ribs (33a and 33b) are provided between mounting plate parts (30a and 31b) and support plate parts (31a and 31b) forming a support bracket (18a). Side plate parts (40a and 40b) forming a distance bracket (17a) are disposed between the support plate parts (31a and 31b), and an outer column (13a). When an adjustment lever (26a) is operated to hold a steering wheel at a position after adjustment, a steering column (6a) is pushed toward an upper side by column pressing parts (42a and 42b) provided at the side plate parts (40a and 40b), and, therefore, a pair of widened parts (43a and 43b) provided at upper parts of the side plate parts (40a and 40b) are pushed and expanded to the outside in a width direction. The widened parts (43a and 43b) are sandwiched between the support plate parts (31a and 31b) and the outer column (13a).
    Type: Application
    Filed: July 18, 2017
    Publication date: October 3, 2019
    Applicant: NSK LTD.
    Inventors: Yoshifumi KUROKAWA, Nobuyuki NISHIMURA
  • Patent number: 10330141
    Abstract: The rolling surface of each ball and a radially outside surface of the inside guide plate are in contact with each other only at two circumferentially set-apart inside contact parts. The rolling surface of each ball and a radially inside surface of the outside guide plate are in contact with each other only at two circumferentially set-apart outside contact parts. At a state after the extensible rotation transmission shaft is assembled, at least the inner surface of the inner-side concave groove is elastically deformed more radially inwards than a state before the assembling, thereby preloading the respective balls.
    Type: Grant
    Filed: July 2, 2015
    Date of Patent: June 25, 2019
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa
  • Patent number: 10288125
    Abstract: A state where the connecting pin is laid across between at least one of the outer diameter side through-holes and the inner diameter side through-hole is maintained by an axial displacement of the connecting pin with respect to the outer diameter side through-hole and the inner diameter side through-hole being regulated based on an engagement between both edges of the connecting pin and a displacement-regulating portion which is a part of the yoke or the bolt.
    Type: Grant
    Filed: January 9, 2015
    Date of Patent: May 14, 2019
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa
  • Publication number: 20190111962
    Abstract: When switching from the unlocked state to the locked state, the moveable-side lock member rotates in a locking direction, so that the fixed-side engagement part and the moveable-side engagement part are friction-engaged or concave-convex-engaged so as to prevent displacement of the adjustment rod in the position adjustment direction. When switching from the locked state to the unlocked state, the moveable-side lock member rotates in an unlocking direction, so that the friction engagement or the concave-convex engagement between the fixed-side engagement part and the moveable-side engagement part is released.
    Type: Application
    Filed: April 6, 2017
    Publication date: April 18, 2019
    Applicant: NSK LTD.
    Inventor: Yoshifumi KUROKAWA
  • Publication number: 20190084610
    Abstract: A portion of the target guide plate interposed between the rolling surface of each ball and an inner surface of the sub-concave groove is supported at the other radial surface opposite to the rolling surface of each ball by the inner surface of the sub-concave groove at a state where one radial surface facing towards the rolling surface of each ball is pressed by the rolling surface of each ball and is thus curved along the rolling surface of each ball.
    Type: Application
    Filed: July 26, 2016
    Publication date: March 21, 2019
    Applicant: NSK LTD.
    Inventor: Yoshifumi KUROKAWA
  • Publication number: 20190031225
    Abstract: A pair of side plate parts of a distance bracket is positioned between a steering column and a pair of support plate parts configuring a support bracket. When an adjustment lever is operated to hold a steering wheel at an adjusted position, the steering column is pushed up by column-pressing parts provided at the side plate parts and a pair of widened parts provided at the top of the side plates is pushed outward in the width direction. The widened parts are sandwiched between the support plate parts and the steering column. This configuration achieves a structure in which the retention force of the distance bracket is improved by the support bracket.
    Type: Application
    Filed: February 2, 2017
    Publication date: January 31, 2019
    Applicant: NSK LTD.
    Inventor: Yoshifumi KUROKAWA
  • Patent number: 10184525
    Abstract: A pin is made of a synthetic resin having an appropriate thermal expansion rate and a low friction coefficient. At a state where respective members configuring a cross shaft universal joint are assembled, a tip portion of the pin is heated and softened, and one yoke is pivotally displaced relative to other yoke. Thereby, it is possible to set a fitting margin of the pin to a bottom inner surface of a bearing cup to an appropriate size and to adjust a shape of an end surface of the pin.
    Type: Grant
    Filed: August 20, 2014
    Date of Patent: January 22, 2019
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa
  • Patent number: 10156267
    Abstract: In a yoke for a cross shaft universal joint, the circumferential phases of the arrangement direction X of a pair of connecting arm parts and the arrangement direction Y of first and second flange parts are shifted from each other. A bolt is tightened to put the first and second flange parts nearer to each other, thereby applying mutually approaching forces to the connecting arm parts in directions inclined relative to the axes of circular holes. Thus, cup bearings incorporated in the circular holes are pressed against the end of a shaft part constituting a cross shaft, thereby enabling suppression of occurrence of shaking motion between the bearings incorporated in the circular holes and the end of the shaft part of the cross shaft rotatably supported by the bearings.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: December 18, 2018
    Assignee: NSK LTD.
    Inventors: Takuma Nakamura, Yoshifumi Kurokawa
  • Publication number: 20180346012
    Abstract: An adjustment rod is inserted in a width direction through displacement-side through holes and one pair of vehicle body-side through holes. One pair of pressing parts are disposed at positions where both end parts of the adjustment rod protrude from respective outer surfaces of one pair of support plate parts. An adjustment lever is secured to the adjustment rod. With the distance between the one pair of pressing parts being reduced by turning the adjustment lever in a predetermined direction, the amount of tightening of an adjustment nut serving as one of the pressing members is adjusted while checking an axial force applied to the adjustment nut. The tightening amount adjustment of the adjustment nut is completed with the checked axial force remaining in a predetermined range.
    Type: Application
    Filed: November 10, 2016
    Publication date: December 6, 2018
    Applicant: NSK Ltd.
    Inventor: Yoshifumi KUROKAWA
  • Publication number: 20180327018
    Abstract: In a clamped state where the interval between both the pressing parts is reduced and both the clamped plate parts are clamped by both the support plate parts, vertical distances from an outer peripheral surface of the adjustment rod to an upper surface and a lower surface of an inner surface of one through-hole of both the through-holes are different, vertical distances from the outer peripheral surface of the adjustment rod to an upper surface and a lower surface of an inner surface of the other through-hole of both the through-holes are different, and sides, where the vertical distance from the outer peripheral surface of the adjustment rod to the inner surface is smaller, are on opposite sides with respect to the vertical direction in one through-hole and the other through-hole.
    Type: Application
    Filed: December 2, 2016
    Publication date: November 15, 2018
    Applicant: NSK LTD.
    Inventor: Yoshifumi KUROKAWA
  • Patent number: 10119575
    Abstract: In a yoke for a cross shaft universal joint, the forming direction of a through hole (17a) and a screw hole (18a) is inclined relative to the axes of circular holes (19a, 19a) formed in a pair of engaging arm parts (12, 12). And, by fastening a bolt (32) to thereby put first and second flange parts (14a, 15a) nearer to each other, mutually approaching forces are applied to the connecting arm parts (12, 12) in a direction inclined relative the axes of the circular holes (19a, 19a). Thus, cup bearings (29) incorporated in the circular holes (19a, 19a) are pressed against the end of a shaft part (28a) constituting a cross shaft (27), thereby enabling suppression of occurrence of shaking motion between the bearings incorporated in the circular holes and the end of the shaft part of the cross shaft supported rotatably by the bearings.
    Type: Grant
    Filed: May 12, 2015
    Date of Patent: November 6, 2018
    Assignee: NSK LTD.
    Inventors: Takuma Nakamura, Yoshifumi Kurokawa
  • Patent number: 10099718
    Abstract: An axially intermediate portion of a spring shaft portion 36 of a torsion bar 14a is provided with a large diameter portion 37, and an outer peripheral surface of the large diameter portion 37 is in contact with or is positioned close to an inner peripheral surface of a hollow output shaft 13a. Accordingly, in an electric power steering device, when one of a pair of coupling shaft portions, which are axially end portions of the torsion bar, to be coupled to a coupling hole of a counter-shaft later is press-fitted into the coupling hole of the counter-shaft, the spring shaft portion of the torsion bar can be prevented from buckling.
    Type: Grant
    Filed: January 9, 2015
    Date of Patent: October 16, 2018
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa
  • Publication number: 20180237052
    Abstract: Non-circular portions (41) are provided in two positions of an adjusting rod (17a) in an axial direction, and the non-circular portions (41) are disposed inside of telescopic-adjusting long holes (16a) of a displacement bracket (13a). Up-down-direction clearances (44a and 44b) which are present between opposite edges of each of the non-circular portions (41) in an up-down direction and inner surfaces of each of the telescopic-adjusting long holes (16a) in the up-down direction in a state where a position of a steering wheel can be maintained are less than up-down-direction clearances (43a and 43b) which are present between the opposite edges of each of the non-circular portions (41) in the up-down direction and the inner surfaces of each of the telescopic-adjusting long holes (16a) in the up-down direction in a state where the position of the steering wheel can be adjusted.
    Type: Application
    Filed: October 26, 2016
    Publication date: August 23, 2018
    Applicant: NSK LTD.
    Inventor: Yoshifumi KUROKAWA
  • Publication number: 20180229755
    Abstract: The slits (25, 25), which is configured to lower a rigidity of the outer column in a radial direction, are provided on both side portions in a width direction, which interpose a central portion in the width direction on an upper half portion, of the tubular outer column (12a) in a state where the slits (25, 25) extend only in an axial direction respectively. A pair of coupling plate parts (28, 28) configuring the column side bracket (16a) are fixed to positions, which interpose each of the slits (25, 25) therebetween from both sides in the width direction, of an outer peripheral surface of the outer column (12a). A structure capable of increasing the frictional force acting between the inner peripheral surface of the outer column and the outer peripheral surface of the inner column as a steering wheel is held at an adjusted position is realized.
    Type: Application
    Filed: October 20, 2016
    Publication date: August 16, 2018
    Applicant: NSK LTD.
    Inventor: Yoshifumi KUROKAWA
  • Publication number: 20180229754
    Abstract: In a steering wheel position adjusting device, an inner side surface of a support plate part (19a) includes a pair of protrusion parts (31a, 31b), which are positioned on both sides of the pressed-part back surfaces (24a) in a front-rear direction and interpose the pressed-part back surfaces (24a), the pressed-part back surface (24a) is positioned on a back side of a portion where the outer side surface of the support plate part (19) is pressed by a driven-side cam (35), and only tip end surfaces of the protrusion parts (31a, 31b) are changed from an unclamped state to a clamped state. In clamped state, the tip end surfaces of the protrusion parts (31a, 31b) and the pressed-part back surfaces (24a) are pressed against an outer side surface of a displacement bracket (16a).
    Type: Application
    Filed: September 21, 2016
    Publication date: August 16, 2018
    Applicant: NSK LTD.
    Inventor: Yoshifumi KUROKAWA
  • Patent number: 10000227
    Abstract: A cylindrical buckling prevention member is fitted on a spring shaft portion of a torsion bar, and an outer peripheral surface of the buckling prevention member is positioned close to or in contact with an inner peripheral surface of a hollow output shaft. Accordingly, when one of a pair of coupling shaft portions, which are axially end portions of the torsion bar, to be coupled to a coupling hole of a counter-shaft later is press-fitted into the coupling hole of the counter-shaft, the spring shaft portion of the torsion bar can be prevented from buckling.
    Type: Grant
    Filed: January 9, 2015
    Date of Patent: June 19, 2018
    Assignee: NSK LTD.
    Inventor: Yoshifumi Kurokawa