A body weight adjustment mechanism for automatic adjustment to a balanced point is provided to improve vibration absorption characteristics and impact absorption characteristics. A torsion angle of a lower frame-side torsion bar when an upper frame is at a balanced point is found in advance, a torsion angle of the lower frame-side torsion bar in a state in which a person is seated is detected, the detected torsion angle is compared with the aforesaid balanced point torsion angle, a control signal is sent to an elastic force adjusting unit, and torsion angles of upper frame-side torsion bars are adjusted so that the torsion angle of the lower frame-side torsion bar becomes equal to the balanced point torsion angle. The upper frame can be set to an appropriate position in an initial state and a static state in which a person is seated and vibration and impact absorption characteristics are improved.

Systems and methods for limiting transmission of vibrations and forces causing vibrations from one element to another are provided. A vibration isolator may include a compressible inner member and an outer member compressible with the inner member. The outer member may be positioned at least partially around the inner member to provide lateral support to the inner member. The outer member may maintain a consistent diameter and compression force when in a compressed state. The outer member may include a tube with a zero or near-zero Poisson's ratio.

A method of operating a vibration control system (VCS) using a single actuator which operates to attenuate a system frequency of a system is provided. The method includes determining whether current vibrations at a non-system frequency exceed a predefined level, determining a system response to compensate for the current vibrations exceeding the predefined level and adjusting the force response of the single actuator to respond to a system frequency and the non-system frequency according to the determined system response toward compensating for the current vibrations.

Systems and methods for limiting transmission of vibrations and forces causing vibrations from one element to another are provided. A vibration isolator may include a compressible inner member and an outer member compressible with the inner member. The outer member may be positioned at least partially around the inner member to provide lateral support to the inner member. The outer member may maintain a consistent diameter and compression force when in a compressed state. The outer member may include a tube with a zero or near-zero Poisson's ratio.

In a power transmission device, a dynamic damper is provided in a power transmission path having at least one damper disposed therein, and has an inertial rotating body that can rotate relative to a transmission rotating member forming part of the power transmission path, and a dynamic damper spring that can provide connection between the transmission rotating member and the inertial rotating body. A preset load is applied to the dynamic damper spring in a non-transmitting state of the power transmission path. The dynamic damper spring is supported on either one of the transmission rotating member and the inertial rotating body so as to apply the preset load to the dynamic damper spring in the non-transmitting state, and a gap is set in a rotational direction in the non-transmitting state between the dynamic damper spring and an other one of the transmission rotating member and the inertial rotating body.

Various implementations include a device for controlling vibration with piecewise-linear nonlinearity. The device includes a stiffness element, a mass, a stopper, and an actuator. The stiffness element is expandable and compressible along an axis. The mass is coupled to the stiffness element. The mass has a resting mass position along the axis. The actuator is coupled to the stopper. The actuator is configured to move the stopper along the axis to vary a gap size. The gap size is measured as a distance between the resting mass position and a resting stopper position.

An apparatus may include an enclosure that includes a plurality of mounting features that are configured to receive information handling systems, a plurality of casters coupled to the enclosure, and first and second dampers. The first damper may have a first resonance frequency and be disposed such that, when the information handling systems are received in the enclosure, the first damper is coupled between the information handling systems and the plurality of casters. The second damper may have a second, different resonance frequency and be disposed such that, when the information handling systems are received in the enclosure, the second damper is coupled between the information handling systems and the plurality of casters.

An air spring includes a closing member, a rolling piston, and an air spring bellows connected to the rolling piston and the closing member to form a fluid-filled pressure chamber. A level control system for supplying and/or discharging fluid may be integrated into the pressure chamber to control level position based on air spring stroke. The level control system may have a control valve and an actuator connected to the control valve. The actuator may include a guide tube coupled to the rolling piston or closing member, and movably arranged within the pressure chamber. An actuating member may include a pin member and may operate the control valve. A compression spring may have a central spring and a biasing spring, and the guide tube may include a control flange coupled to the pin member, and the biasing spring may be supported to press the pin member against the control valve.

In a power transmission device, a dynamic damper is provided in a power transmission path having at least one damper disposed therein, and has an inertial rotating body that can rotate relative to a transmission rotating member forming part of the power transmission path, and a dynamic damper spring that can provide connection between the transmission rotating member and the inertial rotating body. A preset load is applied to the dynamic damper spring in a non-transmitting state of the power transmission path. The dynamic damper spring is supported on either one of the transmission rotating member and the inertial rotating body so as to apply the preset load to the dynamic damper spring in the non-transmitting state, and a gap is set in a rotational direction in the non-transmitting state between the dynamic damper spring and an other one of the transmission rotating member and the inertial rotating body.

A damping assembly for a structure includes a housing with a first fixed end and a second movable opposite end. A first translatable portion of the housing is slidably movable relative to an adjacent second section of the housing, the former being fixedly secured to a base when the structure is under load. A viscous damper disposed within the housing is engaged only after the first translatable section has first moved beyond an initial predetermined distance indicative of a higher amplitude loading event. At least one biasing feature prevents the viscous damper from operating until the first translatable section has first moved beyond the initial predetermined distance.