Embodiments relate to dynamic stroking seats for vertical take-off and landing (VTOL) aircraft. Seat ballast tanks are attached to aircraft seats. The seats are sprung by a fixed or variable load energy absorption system. The weight of a user is determined and assigned to a corresponding seat of the user. Based on the weight of the user, the fluid level in the ballast tank is monitored and adjusted to achieve a target weight range.

A friction damper for dampening out vibrations generated by a drum of a laundry treating machine includes a hollow piston body; a piston rod adapted to move telescopically along a central longitudinal axis of the hollow piston body; a friction element made of a resilient material interposed in between the hollow piston body and the piston rod, wherein a friction occurs when the piston rod moves relative to the hollow piston body; fixation portions provided at free ends of the piston rod and the hollow piston body to connect the friction damper to the laundry treating machine; at least one stopper portion interposed in between the hollow piston body and the piston rod for limitation of a motion of the friction element in a direction of the central longitudinal axis.

A friction damper for dampening out vibrations generated by a drum of a laundry treating machine includes a hollow piston body; a piston rod adapted to move telescopically along a central longitudinal axis of the hollow piston body; a friction element made of a resilient material interposed in between the hollow piston body and the piston rod, wherein a friction occurs when the piston rod moves relative to the hollow piston body; fixation portions provided at free ends of the piston rod and the hollow piston body to connect the friction damper to the laundry treating machine; at least one stopper portion interposed in between the hollow piston body and the piston rod for limitation of a motion of the friction element in a direction of the central longitudinal axis.

A damping mechanism for damping energy resulting from a lateral force on a structure may include a first portion, a second portion configured for longitudinal motion relative to the first portion, a primary energy absorption system configured for frictionally coupling the first portion and the second portion and converting motion of the second portion relative to the first portion into heat energy, and a secondary energy absorption system configured to absorb energy through non-linear deformation and provide a self-centering effect on the damping mechanism.

A damping mechanism for damping energy resulting from a lateral force on a structure may include a first portion, a second portion configured for longitudinal motion relative to the first portion, a primary energy absorption system configured for frictionally coupling the first portion and the second portion and converting motion of the second portion relative to the first portion into heat energy, and a secondary energy absorption system configured to absorb energy through non-linear deformation and provide a self-centering effect on the damping mechanism.

A vibration damper (11) including a movable section ((20) to move in at least one direction; a support section to movably support the movable section; a vibration detector (29) to detect a vibration received by the vibration damper; and a computing processor (30) to compute an amount of displacement of the movable section (20) in a first direction, which is associated with the vibration, based on a detection result of the vibration detector (29) to obtain an amount of correction corresponding to the amount of displacement. The support section moving the movable section (20) in a second direction opposite to the first direction based on the amount of correction obtained by the computing processor (30).

Example embodiments provide mechanical dampers. The mechanical dampers may be applied to dissipate energy in a structure that arises for example from a dynamic load such as seismic activity, vehicle impact, vibration of the structure, wind forces, an explosion, etc. The damper comprises a pair of clamping plates. A shear plate is held between the clamping plates. The shear plate is movable in transverse directions relative to the clamping plates. The damper also comprises a conical wedge coupled between one of the clamping plates and the shear plate. The conical wedge comprises a female conical element and a male conical element that projects into a conical indentation of the female conical element.

Example embodiments provide mechanical dampers. The mechanical dampers may be applied to dissipate energy in a structure that arises for example from a dynamic load such as seismic activity, vehicle impact, vibration of the structure, wind forces, an explosion, etc. The damper comprises a pair of clamping plates. A shear plate is held between the clamping plates. The shear plate is movable in transverse directions relative to the clamping plates. The damper also comprises a conical wedge coupled between one of the clamping plates and the shear plate. The conical wedge comprises a female conical element and a male conical element that projects into a conical indentation of the female conical element.

The present invention relates to a displacement-controlled earthquake-resistant transformer employing a friction damper, including: a device body; an upper frame disposed in an upper portion of the device body to fix the device body; a lower frame disposed in a lower portion of the device body to fix the device body to a base while supporting the device body; and a friction damper unit disposed between the device body and the base to interwork with the device body and the base, and configured to buffer a vibration transmitted to the device body through the base fixed to a ground surface. According to the present invention, seismic energy is absorbed by using a frictional force of a damper in the event of an earthquake, so that damage that may be caused to the transformer by an earthquake shock is prevented.

This base isolation system protects barrel racks from earthquake motions through a pad designed to slide on a prepared surface to critically reduce the amount of energy otherwise transferred to a stack of barrels. The pad is comprised of two layers: a plate, usually steel, and an underlayer, usually a high density plastic. The interaction of the underlayer with the prepared surface depends on a coefficient of static and kinetic friction between the underlayer and the surface that prevents relative movement in normal operation and yet allows the isolation pad to move relative to the surface during a seismic event.