Ishikawajima-Harima Heavy Industries Co., Ltd.

Nippon Cable Co., Ltd.

Ishikawajima-Harima Jukogyo Kabushiki Kaisha

Masao Mutaguchi

Ichiro Tokumura

Nayomon Uno

Yoshinobu Hiranishi

Kiyosi Kawase

Koji Tanida

Hitoshi Nakagawa

Fumio Sato

Mutsuhiro Kazama

Shozo Shigematsu

Takenori Otsuka

Yuji Shiga

Tamotsu Murata

Installed on a top of a structure () is a base stand () against which damping body () movably rests via a linear guide mechanism (). Mounted between the damping body () and the structure () or between the damping body () and a top of a support housing () erected on the structure () is a characteristic-frequency adjusting spring or springs () with an initial tension being applied vertically. Movement of the damping body () causes the spring or springs () to be obliquely and longitudinally expanded to apply horizontal component to the damping body () upon restoring.

Damping device and method for setting natural frequency of damping body in the damping device

A vibration damping arrangement for a gondola of a type having a supporting unit attached to a cable, a hanger suspended from the supporting unit and a carriage suspended from the hanger. A vibration damping device includes an elongated hollow housing. A bottom plate of the housing defines a down-wardly arcuate oscillation track which extends in a direction perpendicular to the cable. A vibration damping body is movably located on the oscillation track such that it can naturally oscillate on the oscillation track in the longitudinal direction of the oscillation track upon vibrations of the carriage. The vibration damping device is located under a seat inside the carriage, suspended from a bottom of the carriage, supported by the hanger above a roof of the carriage or mounted on the roof of the carriage in such a manner that it does not extend beyond width and length of the carriage. The vibration damping device does not substantially occupy a passenger room so that comfortableness is not degraded. A cover may be provided to house the vibration damping device thereby not affecting appearance of the gondola if the vibration damping device is located outside the carriage.

Vibration damping arrangement for cable car

A vibration damping arrangement for a gondola of a type having a supporting unit attached to a cable, a hanger suspended from the supporting unit and a carriage suspended from the hanger. A vibration damping device includes an elongated hollow housing. A bottom plate of the housing defines a downwardly arcuate oscillation track which extends in a direction perpendicular to the cable. A vibration damping body is movably located on the oscillation track such that it can naturally oscillate on the oscillation track in the longitudinal direction of the oscillation track upon vibrations of the carriage. The vibration damping device is located under a seat inside the carriage, suspended from a bottom of the carriage, supported by the hanger above a roof of the carriage or mounted on the roof of the carriage in such a manner that it does not extend beyond width and length of the carriage. The vibration damping device does not substantially occupy a passenger room so that comfortableness is not degraded. A cover may be provided to house the vibration damping device thereby not affecting appearance of the gondola if the vibration damping device is located outside the carriage.

A vibration damping apparatus includes a frame having a rail member and end plates at longitudinal ends of the rail member. The frame is a hollow box-shaped element or a hollow tubular element. The rail member defines a downwardly arcuate surface. The frame is fixed on a vibrant structure. A vibration damping body is movably located on the rail member such that it can naturally oscillate thereon upon vibrations of the structure. An energy of vibration of the structure is transferred to and absorbed by the damping body so that the vibration of the structure is attenuated. By appropriately determining a radius of curvature of the rail member, a natural period of the damping body is set to be equal to that of the structure. First and second magnets are mounted on the end plates and third and fourth magnets are mounted on opposite end faces of the damping body. The first and third magnets have the same polarity and the second and fourth magnets have the same polarity. Therefore, a repulsive force is generated when the first and third magnets approach each other or when the second and fourth magnets approach each other. Consequently, collision between the damping body and the frame ends is prevented.

Vibration damping apparatus

A linear motor has a stator body securely attached to a marine floating structure and a movable body acting as solid mass. In response to a command signal from a controller which phase-controls a signal from rocking-motion sensor, the movable body is forced to move in a direction of reducing the rocking motion against the floating structure in rocking motion, so that the rocking motion of the marine floating structure is reduced or suppressed.

Apparatus for reducing rocking motion of marine floating structure

A vibration damping system adapted for use on top of a structure, comprises: a weight disposed on the top of the structure in a manner such that it can undergo simple harmonic oscillation; an acceleration sensor provided at the structure top for detecting the structure vibration in terms of acceleration; a weight driving mechanism for actuating the weight into the simple harmonic oscillation; and a phase and amplitude controller assembly for performing integration twice on the signal coming from the acceleration sensor, once to obtain the velocity signal, then to obtain the displacement signal, for reversing the sign of the velocity signal when the velocity signal exceeds a predetermined value, and for controlling the weight driving mechanism on the basis of the sign-reversed velocity signal so as to attenuate the vibration of the structure by giving the energy of the weight performing simple harmonic oscillation under control of the phase and amplitude controller assembly to the structure in optimum timing and with an optimum magnitude.

Vibration damping system

A vibration damping system adapted for use on top of a structure, comprises: a weight disposed on the top of the structure in a manner such that it can undergo simple harmonic oscillation; an acceleration sensor provided at the structure top for detecting the structure vibration in terms of acceleration; a weight driving mechanism for actuating the weight into the simple harmonic oscillation; and a phase and amplitude controller assembly for performing integration twice on the signal coming from the acceleration sensor, once to obtain the velocity signal, then to obtain the displacement singal, for reversing the sign of the velocity signal when the velocity signal exceeds a predetermined value, and for controlling the weight driving mechanism on the basis of the sign-reversed velocity singal so as to attenuate the vibration of the structure by giving the energy of the weight performing simple harmonic oscillation under control of the phase and amplitude controller assembly to the structure in optimum timing and with an optimum magnitude.

A vibration damping system adapted for use on top of a structure, comprises: a weight disposed on the top of the structure in a manner such that it can undergo simple harmonic oscillation; an acceleration sensor provided at the structure top for detecting the structure vibration in terms of acceleration; a weight driving mechanism for actuating the weight into the simple harmonic oscillation; and a phase & amplitude controller assembly for performing integration twice on the signal coming from the acceleration sensor, once to obtain the velocity signal, then to obtain the displacement signal, for reversing the sign of the velocity signal when the velocity signal exceeds a predetermined value, and for controlling the weight driving mechanism on the basis of the sign-reversed velocity signal so as to attenuate the vibration of the structure by giving the energy of the weight performing simple harmonic oscillation under control of the phase & amplitude controller assembly to the structure in optimum timing and with an optimum magnitude.

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Yotsukaido, Japan

Masao Mutaguchi