Patents by Inventor Akimasa Yoshida

Akimasa Yoshida 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).

  • Publication number: 20100282011
    Abstract: There is provided a roller screw in which a twisted amount of an unloaded return path is reduced. The roller screw has a screw shaft 1 having a spiral roller-rolling surface is on an outer peripheral surface thereof; a nut 2 having a spiral loaded roller-rolling surface 2a on an inner peripheral surface thereof, the spiral loaded roller-rolling surface being opposed to the roller-rolling surface is of the screw shaft 1; a circulation member 7 arranged in the nut 2 and formed to have an unloaded return path 8 connecting one end and the other end of the loaded roller-rolling surface 2a, whose turn number is less than one, of the nut 2; and a plurality of rollers 4 arranged in a one-turn roller circulation path composed by a loaded roller-rolling path 6 and the unloaded return path 8.
    Type: Application
    Filed: November 14, 2008
    Publication date: November 11, 2010
    Applicant: THK CO., LTD.
    Inventors: Kentaro Nishimura, Tetsuya Miura, Akimasa Yoshida, Soshi Miyahara, Yusuke Todoroki, Takashi Sakuyama
  • Publication number: 20100263467
    Abstract: Provided is a roller screw capable of preventing rollers moving from an unloaded return path to a loaded roller rolling path from coming into collision with a scooping portion. The roller screw has: a screw shaft 1 having a spiral roller rolling surface la formed on an outer peripheral surface thereof; a nut 2 having a loaded roller rolling surface 2a formed in an inner peripheral surface thereof; a circulation member 3 having an unloaded return path connecting one end of the loaded roller rolling surface 2a of the nut 2 to an opposite end thereof; and a plurality of rollers 4 arranged in a loaded roller rolling path 6 and the unloaded return path.
    Type: Application
    Filed: October 29, 2008
    Publication date: October 21, 2010
    Applicant: THK CO., LTD.
    Inventors: Soshi Miyahara, Masahiko Yoshino, Lina Teng, Tsutomu Togashi, Takashi Sakuyama, Kentaro Nishimura, Tetsuya Miura, Akimasa Yoshida, Yusuke Todoroki
  • Publication number: 20100101347
    Abstract: The present invention provides a roller screw which bears loads in both directions along the axis of the screw shaft and which is also capable of preventing interference between each roller end surface and roller rolling grooves. Between roller rolling surfaces 1a, 1b of the screw shaft 1 and roller rolling surfaces 2a, 2b, respectively, of the nut 2, there are formed two or more roller rolling paths 3a, 3b, respectively. In one roller rolling path 3a, plural rollers 4a are parallel-arranged, and also in another roller rolling path 3b, plural rollers 4b are parallel-arranged. The rollers 4a arranged in the one roller rolling path 3a bear a load in one direction (1) along the axis of the screw shaft 1, while the rollers 4b arranged in the other roller rolling path 3b bear a load in the opposite direction (2) along the axis of the screw shaft 1.
    Type: Application
    Filed: June 16, 2006
    Publication date: April 29, 2010
    Applicant: THK CO., LTD.
    Inventors: Masakazu Uesugi, Kentaro Nishimura, Satoshi Fujita, Akimasa Yoshida, Satoru Nagai, Hiroyuki Arai
  • Publication number: 20100058885
    Abstract: A motion guide device is provided which comprises a chain of rollers in which retainers are interposed, in which the chain of rollers is given a degree of freedom of rotation. The motion guide device comprises a track member (5) on which a roller rolling part (5a) is formed which allows rollers (7) to roll on along the roller rolling part; a moving member (6) on which a loaded roller rolling part (6a) facing the roller rolling part (5a) is formed; a plurality of rollers (7) arranged on a roller circulation path containing a loaded roller rolling path (9) formed between the roller rolling part (5a) of the track member (5) and the roller rolling part (6a) of the moving member (6); and a plurality of retainers (8) respectively interposed between rollers of the plurality of rollers (7).
    Type: Application
    Filed: February 3, 2006
    Publication date: March 11, 2010
    Applicant: THK CO., LTD.
    Inventors: Masakazu Uesugi, Kentaro Nishimura, Satoshi Fujita, Akimasa Yoshida, Satoru Nagai, Hiroyuki Arai
  • Publication number: 20100032993
    Abstract: An opening and closing control apparatus for a roof panel for a vehicle includes an opening and closing device for driving the roof panel to open and close, an operation command device for outputting an operation command for opening and closing the roof panel by means of an operation switch, a vehicle speed detecting device, and a controlling device for controlling an operation of the opening and closing device, the controlling device performing an open and close control for operating the opening and closing device to cause the roof panel to move to a predetermined position where the roof panel is opened to a predetermined degree which is specified beforehand on the basis of a vehicle speed when the operation command for opening the roof panel is output by the operation command device.
    Type: Application
    Filed: July 30, 2009
    Publication date: February 11, 2010
    Applicant: AISIN SEIKI KABUSHIKI KAISHI
    Inventors: Akimasa YOSHIDA, Tomoaki Imaizumi, Tatsuo Kamakura
  • Publication number: 20090301246
    Abstract: The present invention provides a screw device which takes a heavy load in one direction along the axis of the screw shaft and only a light load in the opposite direction, the screw device capable of providing ease of control of preloading. The screw device of the present invention has a screw shaft 1 with an outer surface having a ball rolling groove 1a for rolling balls 7 and a roller rolling groove 1b for rolling rollers 6 both spirally formed thereon; a ball nut 4 with an inner surface having a ball rolling groove 4a spirally formed thereon facing the ball rolling groove 1a of the screw shaft 1; a roller nut 5 with an inner surface having a roller rolling groove 5a spirally formed thereon facing the roller rolling groove 1b of the screw shaft 1; a plurality of balls 7 arranged between the screw shaft 1 and the ball nut 4; and a plurality of rollers 6 arranged between the screw shaft 1 and the roller nut 5. The ball nut 4 and the roller nut 5 are connected along an axis of the screw shaft 1.
    Type: Application
    Filed: June 16, 2006
    Publication date: December 10, 2009
    Applicant: THK CO., LTD.
    Inventors: Akimasa Yoshida, Masakazu Uesugi, Kentaro Nishimura, Satoshi Fujita, Satoru Nagai, Hiroyuki Arai
  • Publication number: 20090249912
    Abstract: The present invention provides a roller screw capable of circulating rollers smoothly. A roller screw of the present invention has a screw shaft 1 having a roller rolling surface 1a spirally formed with a lead on an outer surface thereof; a nut 2 having a roller rolling surface 2a spirally formed on an inner surface thereof to face the roller rolling surface 1a of the screw shaft 1; and a plurality of rollers 4 arranged in a rolling path 3 between the roller rolling surface 1a of the screw shaft 1 and the roller rolling surface 2a of the nut 2 and moving around the screw shaft while rotating on rotation axes of the rollers. In this roller screw, each of the rotation axes 4a of the rollers 4 substantially crosses a center line 1b of the screw shaft 1.
    Type: Application
    Filed: March 2, 2006
    Publication date: October 8, 2009
    Applicant: THK CO., LTD.
    Inventors: Hidekazu Michioka, Makoto Iizumi, Satoshi Fujita, Akimasa Yoshida
  • Publication number: 20090084212
    Abstract: Provided is a screw device capable of preventing occurrence of any elevation change at a joint between a ball return path of a circulation member and a loaded ball rolling groove of a nut. The circulation member 12 has end parts 14 and 15 each of which the periphery includes a rolling groove connecting part 22 positioned to the side of a loaded ball rolling groove 11a of a nut 11 and connected to the loaded ball rolling groove 11a of the nut 11 and a scooping part 23 positioned to the side of a ball rolling groove of a screw shaft 1 and scoops up balls 3 from a loaded ball rolling path. The rolling groove connecting part 22 of each of the end parts 14 and 15 is made of resin and formed integral with the nut 11.
    Type: Application
    Filed: April 27, 2007
    Publication date: April 2, 2009
    Applicant: THK CO., LTD.
    Inventors: Hiroshi Niwa, Akimasa Yoshida, Soshi Miyahara, Noriaki Chikamoto, Yasuhiro Kubota
  • Publication number: 20080245170
    Abstract: A roller screw is provided having a structure suitable for circulating rollers. The roller screw has a screw shaft 5 with a spiral roller rolling groove 5a formed on an outer peripheral surface thereof; a nut 6 with a spiral roller rolling groove 6a opposed to the roller rolling groove of the screw shaft and formed on an inner peripheral surface thereof; and a plurality of rollers 7 arranged in a load roller rolling path 9 between the roller rolling groove 5a of the screw shaft 5 and the roller rolling groove 6a of the nut 6. Inside the nut 6 is provided a roller return path 11 extending linearly in parallel with an axis line of the nut 6. To opposite end faces in an axis line direction of the nut 6 are attached direction change path forming members 13 in which direction change paths 10 to connect the load roller rolling path 9 and the roller return path 11 are formed. The roller return path 11 is twisted to rotate an attitude of each of the rollers 7 while the rollers 7 move in the roller return path 11.
    Type: Application
    Filed: September 7, 2005
    Publication date: October 9, 2008
    Applicant: THK Co., Ltd.
    Inventors: Akihiro Teramachi, Hidekazu Michioka, Hiroshi Niwa, Akimasa Yoshida
  • Publication number: 20080110286
    Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.
    Type: Application
    Filed: December 28, 2007
    Publication date: May 15, 2008
    Applicant: THK CO.,LTD.
    Inventors: Kentarou Nishimura, Akimasa Yoshida, Hiroshi Niwa
  • Patent number: 7350434
    Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.
    Type: Grant
    Filed: September 3, 2002
    Date of Patent: April 1, 2008
    Assignee: THK Co., Ltd.
    Inventors: Kentarou Nishimura, Akimasa Yoshida, Hiroshi Niwa
  • Publication number: 20040211280
    Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.
    Type: Application
    Filed: February 5, 2004
    Publication date: October 28, 2004
    Inventors: Kentarou Nishimura, Akimasa Yoshida, Hiroshi Niwa
  • Patent number: 5541615
    Abstract: A three band antenna unit for reception of radio waves in the AM and FM bands and for reception and transmission of radio waves in the UHF band as well as its connection with filters and a communication equipment are disclosed. The antenna unit includes an upper, first element for reception and transmission of a radio wave in the UHF band and a lower, second element for reception of radio waves in the FM band, both connected to a mobile telephone. An AM band signal from the first element is transmitted to the lower, second element through an AM band pass filter. A radio wave signal from the lower, second element is transmitted to an AM/FM tuner through an AM/FM band pass filter.
    Type: Grant
    Filed: March 28, 1994
    Date of Patent: July 30, 1996
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Eiji Koide, Yuichi Murakami, Akimasa Yoshida, Kiyokazu Ieda, Kazuo Sato