Patents Assigned to Takafumi Fujita
  • Patent number: 5867951
    Abstract: A seismic isolation sliding bearing for a structure, is made up of a dish 1 having a conical concave surface having a predetermined inclination or a spherical concave surface in its central portion, and a bearing element 2 in which the bearing element includes a base 3 whose portion for contact with the concave surface of the dish 1 is formed by a low-friction material, and a holder 6 which holds the base 3 so as to press it against the concave surface of the dish 1. The seismic isolation sliding bearing of the present invention neither resonates to the vibration period of any earthquake nor causes a large oscillation during a normal small vibration, but has a restoring force because of its structure which enables the bearing element to readily return to its original position after an earthquake ceases.
    Type: Grant
    Filed: May 29, 1997
    Date of Patent: February 9, 1999
    Assignees: Mitsubishi Steel Mfg. Co., Ltd., Takafumi Fujita
    Inventors: Daisuke Yaguchi, Hiroshi Kurabayashi, Toshio Omi, Nobuyuki Sone, Takeshi Someya, Hirokazu Hora, Akira Matsuda, Takafumi Fujita
  • Patent number: 5255764
    Abstract: A damping apparatus for large structures operable both passively and actively is disclosed which comprises a passive type damping mechanism to be mounted on the structure and including an added mass, spring, dampener, etc., hydraulic cylinders mounted on the structure and connected to the added mass, an electro-hydraulic servo mechanism to switch the hydraulic cylinders between passive and active type operation, and a control unit for switching the electro-hydraulic servo mechanism between passive and active type operation in response to the velocity and displacement of the added mass as well as the velocity of the structure.
    Type: Grant
    Filed: December 8, 1992
    Date of Patent: October 26, 1993
    Assignees: Takafumi Fujita, Mitsubishi Steel
    Inventors: Hiroshi Kurabayashi, Toshio Omi, Hiroshi Miyano, Takafumi Fujita
  • Patent number: 4924640
    Abstract: A vibration controlling apparatus for buildings such as high-rise building, tower and the like comprises a laminated elastic body comprised of elastomer layers and reinforcing plates attached to the building, and an additional mass attached thereto, and reduces the swinging of the building.
    Type: Grant
    Filed: October 14, 1988
    Date of Patent: May 15, 1990
    Assignees: Bridgestone Corporation, Takafumi Fujita
    Inventors: Yoji Suizu, Nobuo Masaki, Takafumi Fujita, Hiroshi Kurabayashi
  • Patent number: 4731966
    Abstract: A vibration energy absorber device includes a first fixing member fixed to a building bottom wall, a second fixing member fixed to a building foundation, a lead elastoplastic member having elasticity, both ends of the elastoplastic member being firmly coupled to the corresponding fixing members, and reinforcing members embedded in the elastoplastic member. The reinforcing members include a plurality of first members of a metal (e.g., iron) having a higher tensile strength than that of the elastoplastic member. The first members are wire rods extending from one end to the other end of the elastoplatic member, and are disposed in the elastoplastic member at equal angular intervals.
    Type: Grant
    Filed: June 10, 1986
    Date of Patent: March 22, 1988
    Assignees: Takafumi Fujita, Kabushiki Kaisha Toshiba, Oiles Industry Co., Ltd.
    Inventors: Takafumi Fujita, Satoshi Fujita, Shigeru Fujimoto, Noboru Narikawa, Chiaki Tsuruya
  • Patent number: 4402483
    Abstract: An earthquake isolation floor comprises a horizontal plate-like support frame having a generally circular or polygonal configuration, a support frame having a horizontal surface with a similar configuration to that of the fundamental frame in a plan view, but of relatively smaller dimensions, a number of horizontal springs disposed radially between the fundamental and support frames with each of the springs being kept in a preset state, and a number of horizontal dampers disposed radially between the fundamental and the support frames, whereby machinery and tools, etc. to be protected against vibration such as caused by an earthquake are adapted to be mounted on the support frame.
    Type: Grant
    Filed: October 23, 1980
    Date of Patent: September 6, 1983
    Assignees: Mitsubishi Steel Mfg. Co., Ltd., Takafumi Fujita
    Inventors: Hiroshi Kurabayashi, Kozo Sakaba, Takafumi Fujita
  • Patent number: 4371143
    Abstract: An earthquake isolation floor comprises a horizontal plate-like support frame having a generally polygonal configuration, a support frame having a horizontal surface with a similar configuration to that of the fundamental frame in plan view, but of relatively smaller dimensions and slidably mounted thereon, and horizontal tensile springs disposed between the fundamental and support frames each in a prestressed condition such that when the support frame is moved relative to the fundamental frame by an earthquake, etc. the springs are caused to be elongated by the fact that their one end in the direction of the movement does not encounter any resistance to the movement, while the other end opposite to the movement is prevented from moving.
    Type: Grant
    Filed: October 23, 1980
    Date of Patent: February 1, 1983
    Assignees: Mitsubishi Steel Mfg. Co., Ltd., Takafumi Fujita
    Inventors: Jiro Ishida, Takafumi Fujita