Patents by Inventor Tatsuya Yamasaki

Tatsuya Yamasaki 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: 8579090
    Abstract: In an electric linear motion actuator for transmitting torque of a rotary shaft (4) to planetary rollers (7) and thus to a linearly driven output member constituted by an outer race member (5), axial movement of a carrier (6) supporting the planetary rollers (7) is restricted, and the outer race member (5) is axially slidably fitted in a radially inner surface of a cylindrical portion (1a) of a housing (1) and is rotationally fixedly coupled to an object to be driven via keys (25) The planetary rollers (7) have their radially inner surfaces rotatably supported on respective support pins (6c) of the carrier (6), and are radially inwardly biased by radial compression ring springs (21) wound around the support pins (6c) so as to envelop the support pins. The planetary rollers (7) are thus pressed against the radially outer surface of the rotary shaft (4).
    Type: Grant
    Filed: October 1, 2009
    Date of Patent: November 12, 2013
    Assignee: NTN Corporation
    Inventor: Tatsuya Yamasaki
  • Publication number: 20130292215
    Abstract: A linear motion actuator includes an outer ring member mounted in a housing, a rotary shaft rotated by a motor, planetary rollers mounted between the outer ring member and the shaft and supported by a carrier rotatable about the shaft. A helical rib is formed on the inner surface of the outer ring member which is engaged in helical grooves formed in outer surfaces of the planetary rollers. When the shaft rotates, the planetary rollers rotate and revolve, thereby axially moving the outer ring member. Uneven axial loads applied to the planetary rollers from the outer ring member are supported by thrust bearings disposed between the planetary rollers and an inner disk of the carrier. Aligning seats are provided between each opposed pair of the planetary rollers and the thrust bearings such that the contact surfaces of the aligning seats shift relative to each other under the uneven axial loads.
    Type: Application
    Filed: January 12, 2012
    Publication date: November 7, 2013
    Inventors: Masaaki Eguchi, Makoto Muramatsu, Tatsuya Yamasaki, Makoto Yasui
  • Publication number: 20130293949
    Abstract: An adhesive composition curable with an active energy ray includes radical polymerizable compounds (A), (B) and (C) as curable components. The composition includes the radical polymerizable compound (A) having an SP value of 29.0 to 32.0 (kJ/m3)1/2 both inclusive in a proportion of 20 to 60% by weight, the radical polymerizable compound (B) having an SP value of 18.0 (kJ/m3)1/2 or more, and less than 21.0 (kJ/m3)1/2 in a proportion of 10 to 30% by weight, and the radical polymerizable compound (C) having an SP value of 21.0 to 23.0 (kJ/m3)1/2 both inclusive in a proportion of 20 to 60% by weight, when the total amount of the adhesive composition is regarded as 100% by weight, and a homopolymer made from each of the radical polymerizable compounds (A), (B) and (C) has a glass transition temperature (Tg) of 60° C. or higher.
    Type: Application
    Filed: December 13, 2011
    Publication date: November 7, 2013
    Applicant: NITTO DENKO CORPORATION
    Inventors: Takeshi Saito, Masashi Shinagawa, Tetsurou Ikeda, Tatsuya Yamasaki, Toshiki Oomine, Masayuki Satake, Shusaku Goto, Takeharu Kitagawa, Minoru Miyatake, Tomohiro Mori, Takashi Kamijo
  • Publication number: 20130186717
    Abstract: A disk brake system includes a disk, brake pads, and a linear motion actuator including an electric motor, a rotary shaft coupled to the motor through a reduction gear mechanism, planetary rollers formed with helical grooves in their outer surfaces, and an outer ring member having a helical rib engages in the helical grooves. The outer ring is coupled to one of the brake pads. When the rotary shaft is rotated by the motor, the outer ring member is moved axially through the planetary rollers, and the brake pads are pressed against the disk. The linear motion actuator further includes a locking mechanism including engaging holes formed in an intermediate gear of the reduction gear mechanism at equal intervals, a locking pin, and a linear solenoid for moving the locking pin until the pin engages in one of the engaging holes, thus locking the motor.
    Type: Application
    Filed: October 17, 2011
    Publication date: July 25, 2013
    Inventors: Makoto Muramatsu, Tatsuya Yamasaki, Masaaki Eguchi, Tomomi Goto
  • Publication number: 20130168192
    Abstract: An electric linear motion actuator is proposed which includes planetary rollers mounted between the radially inner surface of an outer ring member and the radially outer surface of a rotary shaft, and a carrier rotatable about the rotary shaft and including radially movable roller shafts rotatably supporting the respective planetary rollers. Elastic rings each having circumferentially separate ends are each wrapped around the roller shafts to radially inwardly bias the roller shafts, thereby bringing the respective planetary rollers into elastic contact with the radially outer surface of the rotary shaft. Each elastic ring is prevented from rotating relative to the roller shafts, thereby preventing one of the roller shafts from being axially aligned with the gap between the circumferential separate ends, causing the elastic ring to be radially compressed and thus making it impossible for the elastic rings to radially bias the roller shafts.
    Type: Application
    Filed: August 31, 2011
    Publication date: July 4, 2013
    Inventors: Makoto Yasui, Makoto Muramatsu, Masaaki Eguchi, Tatsuya Yamasaki, Tomomi Goto
  • Patent number: 8400586
    Abstract: The present invention provides a polarizing plate excellent in adherence (particularly, under high-temperature and high-humidity conditions) between a polarizer and a protective film. The polarizing plate of the present invention includes: a polarizer; an adhesive layer; an easy-adhesion layer formed of an easy-adhesive composition containing a urethane resin having a carboxyl group and a cross-linking agent; and a protective film containing a (meth)acrylic resin.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: March 19, 2013
    Assignees: Nitto Denko Corporation, Nippon Shokubai Co., Ltd.
    Inventors: Narifumi Ueda, Tatsuya Yamasaki, Michihito Ooishi, Satoshi Itou, Masayuki Satake
  • Publication number: 20130048443
    Abstract: An electric brake system is proposed which includes an electric linear motion actuator and can generate the required braking force with high accuracy. A load sensor (30) is provided in a motion converting mechanism of the actuator which converts the rotary motion of a rotary shaft (4) to which the rotation of an electric motor (2) is transmitted to linear motion of an outer ring member (5) as an output member. The load sensor (30) detects the pushing force with which the outer ring member (5) linearly drives a driven member. With this arrangement, if the driven member is a braking member of an electric brake system, it is possible to directly detect the braking force applied by the driven member and thus to accurately generate the required braking force.
    Type: Application
    Filed: April 27, 2011
    Publication date: February 28, 2013
    Inventors: Makoto Muramatsu, Tatsuya Yamasaki, Masaaki Eguchi, Tomomi Goto
  • Patent number: 8376094
    Abstract: An electromechanical linear-motion actuator includes a rotary shaft, a stationary outer race member, and planetary rollers between the rotary shaft and the outer race member to rotate about their own axes and revolve around the rotary shaft axis. A helical rib is on the radially inner surface of the outer race member or the radially outer surface of the rotary shaft. A helical groove or circumferential grooves are formed in a radially outer surface of each of the planetary rollers in which the helical rib is engaged. A planetary carrier axially faces the planetary rollers, and thrust ball bearings are between the planetary carrier and the respective planetary rollers 16 for preventing rotation of the respective planetary rollers 16 from being transmitted to the planetary carrier 17. Each of the thrust ball bearings comprises a raceway formed on an axial end surface of the corresponding planetary roller.
    Type: Grant
    Filed: May 14, 2008
    Date of Patent: February 19, 2013
    Assignee: NTN Corporation
    Inventors: Tatsuya Yamasaki, Masaaki Eguchi
  • Patent number: 8359607
    Abstract: From an optical disc drive, internal static electricity has to be discharged to the outside to prevent breakage of electric components such as laser diodes. A grounding spring has been used to discharge static electricity from a unit mechanism to the enclosure of the optical disc drive but it is necessary to improve the reliability of the drive in consideration of the dimensional accuracy and workability of the spring. Thus the free end of a grounding spring having a cantilever structure is shaped like an arc and an end of the grounding spring has a curved structure. This configuration improves the dimensional accuracy and workability of the spring, so that the performance of the optical disc drive can be more reliable.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: January 22, 2013
    Assignees: Hitachi Consumer Electronics Co., Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Yoshiaki Yamauchi, Hideyuki Nagamine, Seiji Hamaie, Ikuo Nishida, Tatsuya Yamasaki
  • Patent number: 8341657
    Abstract: An optical pickup, mounting a lens actuator 101 thereon, the lens actuator comprises: a lens 1 having an optical axis in direction in parallel with an optical disc; a holder 2, which holds the lens thereon; a first guide shaft 3 holding the holder, so as to regulate the holder to change a position thereof, into an inner surface direction of a surface having the optical axis of the lens as a normal line vector thereof; a second guide shaft 4, which regulates the holder to change the position thereof, into a normal line vector of an optical disc; and a reed screw, which moves the holder into direction of the optical axis of the lens, wherein a distance between the optical axis of the lens and the optical disc, a distance between a central axis of the first guide shaft and the optical disc, and a distance between a central axis of the second guide shaft and the optical disc are lager than a distance between a central axis of the reed screw and the optical disc.
    Type: Grant
    Filed: August 17, 2009
    Date of Patent: December 25, 2012
    Assignee: Hitachi Media Electronics Co., Ltd.
    Inventors: Tatsuya Yamasaki, Yoshihiro Sato, Seiichi Kato, Katsuhiko Kimura, Takahiro Yamaguchi, Yoshiro Konishi, Hidenao Saito
  • Publication number: 20120305344
    Abstract: A linear motion actuator is provided of which the output member can be smoothly moved linearly even when lateral moment acts on the output member. A carrier (6) supporting planetary rollers (7) is axially immovable, while an outer ring member (5), as the output member, is axially slidably fitted in the radially inner surface of a cylindrical portion (1a) of a housing (1), and is rotationally fixed to a driven member through keys (22). Hard plating layers are formed on the radially outer surface of a rotary shaft (4), the radially outer surfaces of the planetary rollers (7), including helical grooves (7a), and the surface of a helical rib member (5b) which is fixed to the radially inner surface of the outer ring member (5) forming a helical rib.
    Type: Application
    Filed: February 14, 2011
    Publication date: December 6, 2012
    Inventors: Tatsuya Yamasaki, Masaaki Eguchi
  • Patent number: 8240422
    Abstract: A steer-by-wire steering system includes a steering motor, a steering power transmitting mechanism for transmitting a rotation of the steering motor to a steering axle, a toe angle adjusting motor and a toe angle adjusting power transmitting mechanism for adjusting the toe angle upon rotation of the toe angle adjusting motor. A switching mechanism is provided which operates in such a manner that in the event of failure of the steering motor, the rotation of the toe angle adjusting motor in place of the steering motor is transmitted to the steering power transmitting mechanism to enable a wheel turning, but in the event of failure of the toe angle adjusting motor, the wheel turning is carried out only by the steering motor. A hollow motor is employed for one or both of the steering motor and the toe angle adjusting motor.
    Type: Grant
    Filed: December 28, 2011
    Date of Patent: August 14, 2012
    Assignee: NTN Corporation
    Inventors: Tatsuya Yamasaki, Yoshinori Itakura, Nobuyuki Suzuki
  • Publication number: 20120181137
    Abstract: In an electric linear motion actuator, it is proposed to uniformly distribute external thrust loads to respective planetary rollers while the planetary rollers are revolving around a rotary shaft while rotating about their respective axes with a helical rib of an outer ring member in engagement with circumferential grooves of the respective planetary rollers. The planetary rollers (6) have bearing support surfaces (6b) on which thrust bearings (18) are supported, respectively.
    Type: Application
    Filed: September 13, 2010
    Publication date: July 19, 2012
    Inventors: Tatsuya Yamasaki, Masaaki Eguchi
  • Publication number: 20120097470
    Abstract: A steer-by-wire steering system includes a steering motor, a steering power transmitting mechanism for transmitting a rotation of the steering motor to a steering axle, a toe angle adjusting motor and a toe angle adjusting power transmitting mechanism for adjusting the toe angle upon rotation of the toe angle adjusting motor. A switching mechanism is provided which operates in such a manner that in the event of failure of the steering motor, the rotation of the toe angle adjusting motor in place of the steering motor is transmitted to the steering power transmitting mechanism to enable a wheel turning, but in the event of failure of the toe angle adjusting motor, the wheel turning is carried out only by the steering motor. A hollow motor is employed for one or both of the steering motor and the toe angle adjusting motor.
    Type: Application
    Filed: December 28, 2011
    Publication date: April 26, 2012
    Applicant: NTN CORPORATION
    Inventors: Tatsuya Yamasaki, Yoshinori Itakura, Nobuyuki Suzuki
  • Publication number: 20120073393
    Abstract: An actuator has planetary rollers disposed between a rotor shaft of an electric motor and an outer ring member fixed around the rotor shaft. The planetary rollers are rotated about the axis of the rotor shaft and about their own axes, thereby converting rotary motion of the rotor shaft to linear motion of the planetary rollers A helical groove is formed in the radially outer surface of each planetary roller in which a helical rib formed on the radially inner surface of the outer ring member is received. The helical groove has a pitch equal to that of the helical rib and a lead angle different from that of the helical rib. The amount of the linear motion of the planetary rollers relative to the amount of the rotary motion of the rotor shaft is determined by the difference in lead angle between the helical groove and the helical rib.
    Type: Application
    Filed: December 7, 2011
    Publication date: March 29, 2012
    Inventor: Tatsuya YAMASAKI
  • Patent number: 8109370
    Abstract: An actuator has planetary rollers disposed between a rotor shaft of an electric motor and an outer ring member fixed around the rotor shaft. The planetary rollers are rotated about the axis of the rotor shaft and about their own axes, thereby converting rotary motion of the rotor shaft to linear motion of the planetary rollers A helical groove is formed in the radially outer surface of each planetary roller in which a helical rib formed on the radially inner surface of the outer ring member is received. The helical groove has a pitch equal to that of the helical rib and a lead angle different from that of the helical rib. The amount of the linear motion of the planetary rollers relative to the amount of the rotary motion of the rotor shaft is determined by the difference in lead angle between the helical groove and the helical rib.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: February 7, 2012
    Assignee: NTN Corporation
    Inventor: Tatsuya Yamasaki
  • Publication number: 20110276231
    Abstract: A steer-by-wire steering device, in which when a turning motor fails, a toe angle adjusting motor is converted into a drive source for steering the wheel, is provided. A steering wheel not mechanically coupled with a steering axle; a steering angle sensor; a steering reactive force motor; and a steering control unit are provided therein. In addition to a turning power transmitting mechanism for transmitting power from a turning motor to the steering axle, the use is made of a toe angle adjusting power transmitting mechanism for transmitting power from a toe angle adjusting motor to the steering axle. When the turning motor fails, a switching unit for disconnecting the turning motor from the turning power transmitting mechanism, locking of the toe angle adjusting power transmitting mechanism and turning the wheel using the toe angle adjusting motor is interposed between those transmitting mechanisms.
    Type: Application
    Filed: January 6, 2010
    Publication date: November 10, 2011
    Inventors: Nobuyuki Suzuki, Tatsuya Yamasaki
  • Publication number: 20110258650
    Abstract: From an optical disc drive, internal static electricity has to be discharged to the outside to prevent breakage of electric components such as laser diodes. A grounding spring has been used to discharge static electricity from a unit mechanism to the enclosure of the optical disc drive but it is necessary to improve the reliability of the drive in consideration of the dimensional accuracy and workability of the spring. Thus the free end of a grounding spring having a cantilever structure is shaped like an arc and an end of the grounding spring has a curved structure. This configuration improves the dimensional accuracy and workability of the spring, so that the performance of the optical disc drive can be more reliable.
    Type: Application
    Filed: April 13, 2011
    Publication date: October 20, 2011
    Inventors: Yoshiaki YAMAUCHI, Hideyuki Nagamine, Seiji Hamaie, Ikuo Nishida, Tatsuya Yamasaki
  • Publication number: 20110247904
    Abstract: An object is to allow smooth guidance of the linear motion of an output member even when lateral moment acts on the output member, and to make it possible to stably transmit torque of a rotary shaft to respective planetary rollers without applying a preload to the planetary rollers by negative gaps between the rollers and the radially outer surface of the rotary shaft and between the rollers and the radially inner surface of an outer race member. The axial movement of a carrier (6) supporting the planetary rollers (7) is restricted, and the outer race member (5) is axially slidably fitted in the radially inner surface of a cylindrical portion (1a) of a housing (1) and is rotationally fixedly coupled to an object to be driven by means of keys (25), whereby the outer race member (5) serves as a linearly driven output member.
    Type: Application
    Filed: October 1, 2009
    Publication date: October 13, 2011
    Inventor: Tatsuya Yamasaki
  • Publication number: 20110197210
    Abstract: An optical disc drive with low vibration and low noise without risk of damage to components and injury caused by ejection of the disc tray with the rotating optical disc from a housing is provided by simple structure. In a disc-tray scheme of the optical disc drive, a brake member attached to the inside of the housing is placed to be in contact with the optical disc sliding thereon when the disc tray is in a predetermined position except the disc recording/reproducing position and the disc loading/unloading position, and to be connected to the disc tray when the disc tray is in the disc recording/reproducing position.
    Type: Application
    Filed: February 8, 2011
    Publication date: August 11, 2011
    Inventors: Tatsuya YAMASAKI, Yoshiaki Yamauchi, Nozomu Harada, Sojiro Kirihara, Ikuo Nishida