Patents by Inventor Kunitake Matsushita

Kunitake Matsushita 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: 6870291
    Abstract: There is provided a stepping motor of low vibration realized by reducing cogging with a simple structure while maintaining the performances such as torque.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: March 22, 2005
    Assignee: Minebea Co. Ltd.
    Inventors: Yuzuru Suzuki, Taketoshi Ohyashiki, Kunitake Matsushita
  • Publication number: 20050046305
    Abstract: A claw-pole type stepping motor comprises: a rotor assembly shaped substantially cylindrical, and having a center shaft; and a stator assembly composed of two cup-shaped stator units which are coupled to each other coaxially so as to axially sandwich the rotor assembly, and which each include a bobbin having a magnet wire wound therearound, and two pole tooth arrays magnetically connected to each other and shifted in phase from each other by an electrical angle of 180 degrees. In the motor, each stator unit further includes a cover ring which protects the magnet wire wound around the bobbin against resin injected when the stator unit is resin-molded for an integrated solid structure. The motor structured as described above can be successfully resin-molded so as to enable elimination of a motor case, thus achieving downsizing for the dimension of the eliminated motor case while maintaining a sufficient mechanical strength.
    Type: Application
    Filed: August 30, 2004
    Publication date: March 3, 2005
    Inventors: Kunitake Matsushita, Takayuki Yamawaki, Toshihiko Nagata
  • Publication number: 20050046291
    Abstract: In order to reduce cost through reduction in material cost and improvement of productivity, in a linear type actuator comprising: a stator unit having coils consisting of wound magnet wires and housed inside stator sub-assemblies and pole teeth arranged on the inner circumference thereof; a rotor unit having a field magnet arranged on the outer circumference thereof and rotatably disposed so as to oppose the pole teeth with a given gap; an output shaft attached to a center portion of the rotor unit and movble in the axial direction thereof; and converting means provided on the innermost diametral circumferential surface of the rotor unit and adapted to convert rotary motion of the rotor unit into linear motion of the output shaft, the converting means is made of a material different from that of the rotor unit.
    Type: Application
    Filed: October 8, 2004
    Publication date: March 3, 2005
    Inventors: Yuzuru Suzuki, Sakae Fujitani, Naoyuki Harada, Kunitake Matsushita
  • Publication number: 20050023918
    Abstract: There is provided a stepping motor of low vibration realized by reducing cogging with a simple structure while maintaining the performances such as torque.
    Type: Application
    Filed: August 31, 2004
    Publication date: February 3, 2005
    Inventors: Yuzuru Suzuki, Taketoshi Ohyashiki, Kunitake Matsushita
  • Publication number: 20050006960
    Abstract: A claw-pole type stepping motor comprises: a rotor which is shaped substantially cylindrical, and which has a rotary shaft at its radial center; and two stators which are shaped like a cup, each have at least one magnetic coil, are coupled to each other so as to rotatably house the rotor with their magnetic coils located respectively toward both axial end faces of the rotor, and which each have two pole tooth arrays magnetically connected to each other such that magnetic phase difference therebetween at tips of respective pole teeth is 180 degrees in terms of electrical angle, and in the motor thus structure, three pipes of aluminum go axially through the two stators so as to hold together the two stators.
    Type: Application
    Filed: July 2, 2004
    Publication date: January 13, 2005
    Inventors: Kunitake Matsushita, Takayuki Yamawaki, Toshihiko Nagata, Naoyuki Harada
  • Patent number: 6838792
    Abstract: A low-profile stepping motor comprises: an upper twin-stator yoke plate composed of first and second upper stator yokes; a lower twin-stator yoke plate composed of first and second lower stator yokes; first and second coil units fixedly sandwiched between the upper and lower stator yoke plates so as to be arranged horizontally flush with each other; and a rotor assembly including a cylindrical magnet and disposed between the first and second coil units. In the stepping motor, one of the upper and lower twin-stator yoke plates is structured such that one half of its pole teeth partitioned in half by a predetermined datum line and open spaces each residing between two adjacent pole teeth of the other half are positioned symmetrically about the predetermined datum line, whereby the one twin-stator yoke plate can be used in common to the other twin-stator yoke plate.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: January 4, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Kunitake Matsushita, Hiroshi Sano, Toshihiko Nagata
  • Patent number: 6833649
    Abstract: An electric rotary machine is provided, in which a stator armature includes a stator ring that encloses a plurality of salient poles each with a pole tooth thereby forming a magnetic circuit, and in which the inner surface of the stator ring is made flat at portions to be in contact with the outer end faces of the pole teeth so that the stator ring can make surface-to-surface contact with the pole teeth without any air gap therebetween so as to secure a well-balanced magnetic circuit.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: December 21, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Yuzuru Suzuki, Kunitake Matsushita, Seiichi Matsuura
  • Patent number: 6824490
    Abstract: A planetary gear reduction device with a torque limiter function includes a housing, an input shaft rotatably supported by one end of the housing and connected to a power source so as to input a torque from the power source, an output shaft rotatably supported by the other end of the housing so as to output the torque from the power source, a reduction gear train provided between the input shaft and the output shaft and constituted of a plurality of gears meshing with one another, and a torque limiting mechanism mounted in the reduction gear train. In this device, when an excessive torque is generated in the output shaft, torque transmission from the input shaft to the output shaft is disconnected by the action of the torque limiting mechanism.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: November 30, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Yuzuru Suzuki, Kunitake Matsushita, Kazuo Muramatsu
  • Patent number: 6822351
    Abstract: A low-profile stepping motor has a stator assembly structured such that first and second coil units are disposed flush with each other horizontally and are sandwiched between upper and lower stator yoke pieces each comprising first and second stator yokes which are punched out integrally with each other, are shaped symmetrically, and which each have a plurality of pole teeth along its semi-circular inner circumference. The upper and lower stator yoke pieces are fixedly put together by means of two studs lodged fittingly inside respective bobbins of the first and second coil units such that the studs have their both ends tightly engaging with holes formed in the upper and lower stator yoke pieces, whereby the coil units are surely held between the upper and lower stator yoke pieces.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: November 23, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Kunitake Matsushita, Hiroshi Sano, Toshihiko Nagata
  • Patent number: 6822356
    Abstract: An electric rotary machine includes a stator armature which comprises: a stator ring; a plurality of discrete salient poles each including a pole tooth and a coil, disposed inside the stator ring thereby forming a magnetic circuit, and fixed by a molding resin injected inside the stator ring from an injection port of a molding die; and a plurality of barrier walls. Each of the barrier walls is disposed between the injection port of the molding die and two coil terminal pins to which the coil has its both wire terminations connected respectively.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: November 23, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Yuzuru Suzuki, Seiichi Matsuura, Kunitake Matsushita, Kazuo Muramatsu
  • Patent number: 6812599
    Abstract: A low-profile stepping motor comprises: a first stator unit including first upper and lower stator yokes each having a plurality of pole teeth which are formed along its semicircular inner circumference, and a first coil unit fixedly sandwiched between the first upper and lower stator yokes; a second stator unit including second upper and lower stator yokes formed as one piece integrally with the first upper and lower stator yokes, respectively, and each having a plurality of pole teeth which are formed along its semicircular inner circumference, and a second coil unit fixedly sandwiched between the second upper and lower stator yokes; a rotor assembly rotatably disposed in a circular open space defined by the pole teeth of the first and second stator units; and a spacer block disposed between the upper and lower stator yokes and adapted to surround the first and second coil units and the pole teeth.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: November 2, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Kunitake Matsushita, Hiroshi Sano, Toshihiko Nagata
  • Patent number: 6791223
    Abstract: There is provided a stepping motor of low vibration realized by reducing cogging with a simple structure while maintaining the performances such as torque.
    Type: Grant
    Filed: October 25, 2001
    Date of Patent: September 14, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Yuzuru Suzuki, Taketoshi Ohyashiki, Kunitake Matsushita
  • Publication number: 20040165395
    Abstract: A mechanism for deflecting a headlamp optical axis comprises a connecting lever, a bracket, a stepping motor, a front end plate, and a traveling block. The bracket is attached to an outside frame constituting an automotive vehicle body, and the stepping motor is attached to the bracket in a horizontally movable manner. The stepping motor has a rotary shaft which has a screw formed thereon and engaging threadedly with the traveling block. The connecting lever is attached to the outside frame in a horizontally movable manner. In the mechanism structured above, when the rotary shaft rotates, the traveling block is caused to travel along the rotary shaft thereby causing the both ends of the connecting lever to move in respective arc paths, whereby an optical axis of a headlamp attached to one of the both ends of the connecting lever is deflected.
    Type: Application
    Filed: February 24, 2004
    Publication date: August 26, 2004
    Inventors: Yuzuru Suzuki, Kunitake Matsushita, Sylvie Belavsky
  • Patent number: 6768242
    Abstract: There is disclosed a rotor structure of an inner rotor type motor comprising a stator including annular stator yokes each having a plurality of pole teeth along an inner circumference thereof and coils arranged inside the stator yokes, each coil constructed by winding a magnet wire and a rotor rotatably disposed with a small gap from the pole teeth of the annular yokes and having a permanent magnet arranged opposite to the pole teeth. The permanent magnet comprises a plurality of discrete segment magnets, which are arranged apart from each other by resin molding. Thus, the inexpensive inner rotor type motor rotor can be structured by using the magnet having excellent magnetic characteristics.
    Type: Grant
    Filed: November 16, 2000
    Date of Patent: July 27, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Yuzuru Suzuki, Kunitake Matsushita
  • Publication number: 20040135448
    Abstract: In a motor, a shaft passes through a magnet of a rotor and is fixed to the magnet by way of a rotor sleeve formed by resin-molding between the magnet and the shaft. A resin-molded boss is fixed to a front end of a stator, has a center hole, and defines an inner surface continuous from the center hole and beveled so as to obliquely face a front end of the rotor sleeve. A plurality of bearing balls are rotatably disposed between the front end of the rotor sleeve and the beveled inner surface of the boss, thereby constituting a ball bearing which rotatably supports the shaft. Thus, the shaft is prevented from bowing, whereby the motor achieves a high rotational accuracy of the shaft without an additional bearing attached separately.
    Type: Application
    Filed: December 22, 2003
    Publication date: July 15, 2004
    Inventors: Kunitake Matsushita, Hiroshi Sano, Toshihiko Nagata
  • Publication number: 20040104626
    Abstract: A low-profile stepping motor comprises: an upper twin-stator yoke plate composed of first and second upper stator yokes; a lower twin-stator yoke plate composed of first and second lower stator yokes; first and second coil units fixedly sandwiched between the upper and lower stator yoke plates so as to be arranged horizontally flush with each other; and a rotor assembly including a cylindrical magnet and disposed between the first and second coil units. In the stepping motor, one of the upper and lower twin-stator yoke plates is structured such that one half of its pole teeth partitioned in half by a predetermined datum line and open spaces each residing between two adjacent pole teeth of the other half are positioned symmetrically about the predetermined datum line, whereby the one twin-stator yoke plate can be used in common to the other twin-stator yoke plate.
    Type: Application
    Filed: October 2, 2003
    Publication date: June 3, 2004
    Applicant: Minebea Co., Ltd.
    Inventors: Kunitake Matsushita, Hiroshi Sano, Toshihiko Nagata
  • Publication number: 20040100161
    Abstract: A low-profile stepping motor comprises: a first stator unit including first upper and lower stator yokes each having a plurality of pole teeth which are formed along its semicircular inner circumference, and a first coil unit fixedly sandwiched between the first upper and lower stator yokes; a second stator unit including second upper and lower stator yokes formed as one piece integrally with the first upper and lower stator yokes, respectively, and each having a plurality of pole teeth which are formed along its semicircular inner circumference, and a second coil unit fixedly sandwiched between the second upper and lower stator yokes; a rotor assembly rotatably disposed in a circular open space defined by the pole teeth of the first and second stator units; and a spacer block disposed between the upper and lower stator yokes and adapted to surround the first and second coil units and the pole teeth.
    Type: Application
    Filed: September 26, 2003
    Publication date: May 27, 2004
    Applicant: Minebea Co., Ltd
    Inventors: Kunitake Matsushita, Hiroshi Sano, Toshihiko Nagata
  • Publication number: 20040084201
    Abstract: A support hole, screw holes, and eleven orientating holes are formed in a plate. The orientating holes are each positioned asymmetric to any other thereof about a center of the plate.
    Type: Application
    Filed: October 21, 2003
    Publication date: May 6, 2004
    Inventors: Hideki Sakiyama, Hiroshi Sano, Kunitake Matsushita
  • Publication number: 20040080233
    Abstract: A low-profile stepping motor has a stator assembly structured such that first and second coil units are disposed flush with each other horizontally and are sandwiched between upper and lower stator yoke pieces each comprising first and second stator yokes which are punched out integrally with each other, are shaped symmetrically, and which each have a plurality of pole teeth along its semi-circular inner circumference. The upper and lower stator yoke pieces are fixedly put together via the coils such that hollow-cylindrical protrusions formed in the upper and lower stator yoke pieces are inserted into through-holes of first and second coil bobbins from the upper and lower sides, respectively, and have their abutting end surfaces welded, bonded or otherwise fixed to each other, whereby the coil units are surely held between the upper and lower stator yoke pieces.
    Type: Application
    Filed: September 26, 2003
    Publication date: April 29, 2004
    Applicant: Minebea Co., Ltd.
    Inventors: Kunitake Matsushita, Hiroshi Sano, Toshihiko Nagata
  • Patent number: 6717319
    Abstract: An electric rotary machine comprises a cylindrical pole tooth ring and a plurality of salient poles each including a pole tooth. The salient poles are each positioned and fixed such the pole tooth makes firm contact with the pole tooth ring by means of each of a plurality of mechanisms, which are arrayed circumferentially on the pole tooth ring, and which each comprise bend-ups adapted to be elastically deformed when the pole tooth is fitted into the mechanism.
    Type: Grant
    Filed: January 28, 2003
    Date of Patent: April 6, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Yuzuru Suzuki, Seiichi Matsuura, Kunitake Matsushita, Masato Hata, Sakae Fujitani