Abstract: A robot arm including a rotating body connected to a base, an arm rotating about a central axis of the rotating body, a moving pulley provided at the arm and revolving along a circular track which is concentric with the rotating body, a reference pulley provided at the base and positioned on an inner side with respect to the circular track, a spring embedded in the arm and compressed or stretched in a lengthwise direction of the arm, a string compressing the spring and wound around the moving pulley and the reference pulley, and a plurality of roller bearings arranged to be spaced apart from each other along an outer circumference of the rotating body, rotating about a rotation axis parallel to the central axis of the rotating body, and configured to be in contact with the string is provided.

Abstract: A spheroidal framework having sensors is mounted to a multi-rotor aircraft with elastic members and adjustable aircraft mounts whereby transmission of vibration from the aircraft to the framework is dampened and whereby the framework's position relative to the aircraft's center of gravity may be changed by selectively tensioning the elastic members and by adjusting the position of the aircraft mounts.

Abstract: Provided is a vehicle seat having a seat cushion, a submarine bar, an airbag main body, a bag retainer, and a transmission member. The seat cushion is shifted by a tilting mechanism or a lifting mechanism. The submarine bar is suspended across side frames. The airbag main body inflates and deploys inside the seat cushion. The bag retainer is at least partially disposed inside the airbag main body and retains an inflator. The transmission member transmits, to the submarine bar, a load that acts on the bag retainer when the airbag main body inflates and deploys in a state where the seat cushion has been shifted upward.

Abstract: Described herein is an arm supporting exoskeleton, comprising an arm link mechanism. The arm link mechanism comprises a proximal link, a distal link, an arm coupler, and a variable force generator. The distal link is rotatable relative to the proximal link. The arm coupler is adapted to couple an upper arm of a person to the distal link. The variable force generator comprises a first spring and a second spring, configured to create a torque between the proximal link and the distal link. In the first force mode, the variable force generator exhibits a first stiffness rate defined by the first spring that supports the upper arm of the person against gravity forces and. In the second force mode, the variable force generator exhibits a second stiffness rate defined by the first spring and the second spring that supports the upper arm of the person against the gravity forces.

Abstract: A damper for reinforcing earthquake resistance according to the present invention includes a first supporting part mounted in a building structure, a second supporting part mounted on a support structure movably disposed to be separated from the building structure, and disposed to face the first supporting part, and a damper part connecting the first supporting part with the second supporting part and absorbing energy generated by an earthquake.

Abstract: An item of seating furniture having a sitting surface which is mounted on a frame structure and which can be lifted from a lower position to an upper position by means of a lifting device, said lifting device having a scissors mechanism that has at least two limb parts which can pivot relative to each other. At least one spring element which is prestressed in the lower position, acts in the direction of the upper position and can be arranged in at least two different angular positions engages with at least one of the limb parts which is mounted via an articulated joint to the frame structure.

Abstract: The present invention relates to an energy absorbing apparatus. Specifically, the apparatus comprises a first disk and a second disk atop the first disk, and a plurality of collapsible arms around the perimeter of the disks connecting the first disk and the second disk, and an elastic material disposed between at least two of the collapsible arms, wherein collapsing of the arms causes the elastic material to stretch, storing kinetic energy from the vertical direction as potential energy in the horizontal direction, wherein release of the potential energy from the elastic material causes the arms to return to an uncollapsed state. Systems utilizing the energy absorbing apparatus, methods of making and methods of using the same are further provided.

Abstract: An active vibration control device is provided that is configured to control the position of a body relative to a reference frame. The control device includes sensors that provide input signals corresponding to movement of the body in at least one direction, a rotary rotary actuator configured to control the position of the body, and four-bar linkage connecting the rotary rotary actuator to the body. The linkage converts the rotary motion output from the rotary actuator into a linear motion of the body. The controller, based on the input signals from the reference frame sensors, provides control signals to the rotary rotary actuator which acts through the linkage to position the body in the at least one direction relative to the position of the reference frame.

Abstract: A support apparatus for suspending a display includes two suspenders and two repositioning units. Each suspender includes a connection member, a joint member, and two parallel arms extending between and pivoted to the connection member and the joint member. Each repositioning unit is connected between a corresponding arm and a corresponding one of the connection member and the joint member, and includes a variable-length cylinder. One of the repositioning units further includes a linking rod having opposite ends connected pivotally and respectively to a corresponding variable-length cylinder and a corresponding one of the connection member and the joint member of a respective suspender.

Abstract: A vehicle seat having an oscillatory scissor-type stand and a damper that is articulated at two parts of the scissor-type stand which are movable relative to one another. One end of the damper is articulated at a pin that extends in transverse direction of the seat and extends between two structural parts arranged at a distance from one another in transverse direction of the seat at a part of the scissor-type stand. A bearing bushing is arranged with its axial bushing opening on a tubular component part enclosing the pin, wherein the bushing opening has a spherical longitudinal section with the greatest diameters at the two axial ends and the smallest diameter in the middle of the bushing opening. The bearing bushing is enclosed by a bearing ring of the damper having a shorter axial length than the bearing bushing and is arranged on the bearing bushing at an axial distance from the two ends of the bearing bushing so as to be secured against axial displacement.

Abstract: A system and method for processing an image edge includes an edge filter that processes an image input to generate edge data. An edge-smoothing filter processes the edge data to filter-out image noise and preserve the image edge, thus generating edge-smoothed data. An adder adds the edge-smoothed data to the image input, thus generating an edge-smoothed image.

Abstract: A first fastening portion (100) for fastening a cylinder block (20) and a bracket (50) to each other and a second fastening portion (200) for fastening a crank case (30) and the bracket (50) to each other are so provided as to have interposed therebetween a fastening bolt (40) for fastening the cylinder block (20) and the crank case (30) to each other.

Abstract: An active vibration control device is provided that is configured to control the position of a body relative to a reference frame. The control device includes sensors that provide input signals corresponding to movement of the body in at least one direction, a rotary rotary actuator configured to control the position of the body, and four-bar linkage connecting the rotary rotary actuator to the body. The linkage converts the rotary motion output from the rotary actuator into a linear motion of the body. The controller, based on the input signals from the reference frame sensors, provides control signals to the rotary rotary actuator which acts through the linkage to position the body in the at least one direction relative to the position of the reference frame.

Abstract: A holding device for a scale including a support body, a first solid body link and a second body link. The first solid body link acts as a connection between a first longitudinal side of a scale and the support body, via which the scale can be seated, shiftable in a measuring direction, on the support body. The second solid body link acts as a connection between a second longitudinal side of the scale and the support body, via which the scale can be seated, shiftable in the measuring direction, on the support body, wherein the second longitudinal side and the first longitudinal side are arranged opposite each other.

Abstract: An active vibration control device is provided that is configured to control the position of a body relative to a reference frame. The control device includes sensors that provide input signals corresponding to movement of the body in at least one direction, a rotary motor configured to control the position of the body, and four-bar linkage connecting the rotary motor to the body. The linkage converts the rotary motion output from the motor into a linear motion of the body. The controller, based on the input signals from the reference frame sensors, provides control signals to the rotary motor which acts through the linkage to position the body in the at least one direction relative to the position of the reference frame.

Abstract: The invention relates to a constant bearer for moving loads, especially pipelines and similar, comprising a fastening part, a load-bearing part, and a spring system located between the fastening part and the load-bearing part for generating a constant bearing force, where the spring system displays a main spring assembly absorbing the load and a compensating device to compensate for changing spring forces of the main spring assembly.

Abstract: A force exerting device having a force exerting structure including a load arm as a first side, pivotable about a load pivot, a resilient member attached to the load arm and to a termination point and forming a second side of the force exerting structure. The third side of the structure is formed by a line from the termination point to the load pivot. A first adjustment mechanism moves the termination point to change the length of the third side of the structure. A second adjustment mechanism moves the termination point in a direction different than the first adjustment direction so the termination point location can cross a substantially plumb line passing through the load pivot. A force modification device may be included to dynamically adjust the resilient member termination point position in response to motion of the load arm.

Abstract: An axial damper for elements having a cylindrical, rectangular or squared section, includes two identical fixing clamps, each fixing clamp including an upper part and a lower part connected to each other by a clamping device to be wound around the elements. At least two rafter-tie-rods are each connected at two ends thereof to the clamps. The rafter-tie-rods are placed equidistant from each other in the case of more than two rafter-tie-rods. The damper also includes two damping systems, each including two or more blocks of elastomeric material, with a pre-compressed elastic element interposed therebetween.

Abstract: A mount for carrying a display and like devices. The mount includes a base and a support pivotally coupled to the base. The support includes a mounting surface to carry at least one device. At least one rail constrains movement of the base along a horizontal plane. A pivot actuator is configured to pivot the support between a vertical position and a horizontal position. The mounting surface is substantially orthogonal to the horizontal plane in the vertical position. In the horizontal position, the mounting surface is substantially parallel to the horizontal plane.

Abstract: The invention relates to a constant bearer for moving loads, especially pipelines and similar, comprising a fastening part, a load-bearing part, and a spring system located between the fastening part and the load-bearing part for generating a constant bearing force, where the spring system displays a main spring assembly absorbing the load and a compensating device to compensate for changing spring forces of the main spring assembly.

Abstract: The invention relates to a constant bearer for moving loads, especially pipelines and similar, comprising a fastening part, a load-bearing part, and a spring system located between the fastening part and the load-bearing part for generating a constant bearing force, where the spring system displays a main spring assembly absorbing the load and a compensating device to compensate for changing spring forces of the main spring assembly.

Abstract: A force exerting device having a force exerting structure including a load arm as a first side, pivotable about a load pivot, a resilient member attached to the load arm and to a termination point and forming a second side of the force exerting structure. The third side of the structure is formed by a line from the termination point to the load pivot. A first adjustment mechanism moves the termination point to change the length of the third side of the structure. A second adjustment mechanism moves the termination point in a direction different than the first adjustment direction so the termination point location can cross a substantially plumb line passing through the load pivot. A force modification device may be included to dynamically adjust the resilient member termination point position in response to motion of the load arm.

Abstract: A force exerting device having a force exerting structure including a load arm as a first side, pivotable about a load pivot, a resilient member attached to the load arm and to a termination point and forming a second side of the force exerting structure. The third side of the structure is formed by a line from the termination point to the load pivot. A first adjustment mechanism moves the termination point to change the length of the third side of the structure. A second adjustment mechanism moves the termination point in a direction different than the first adjustment direction so the termination point location can cross a substantially plumb line passing through the load pivot. A force modification device may be included to dynamically adjust the resilient member termination point position in response to motion of the load arm.

Abstract: An adjustable lift support apparatus includes a holder, a base, a first fixed shaft, a support, a second fixed shaft, and a transmission shaft. The first fixed shaft is connected to the base and the holder, and a first gear is mounted thereon. The second fixed shaft is connected to the support and the holder, and a fourth gear is mounted thereon. The transmission shaft is rotatably mounted on the holder, and a second gear is mounted thereon meshing with the first gear and a third gear is mounted thereon meshing with the fourth gear. The support is lifted or lowered by a force to make the second gear rotate with respect to the first gear which is fixed and the third gear rotate with respect to the fourth gear, so as to adjust the height of the support and maintain an included angle between the support and the base.

Abstract: A suspension for a vehicle seat having four bellcranks which guide the seat substantially vertically, oscillate on a central pivot on elevated stationary pivots mounted on a lower frame, with upper arms of the bellcranks pivotally attached to a seat cushion upper frame and the lower arms indirectly attached to adjustable tension springs that are attached to the upper frame; the lower ends with substantial inward offsets so as to rotate downwardly toward the mounting deck of the vehicle while clearing the lower frame and adjustable sliders; the bellcranks being coupled longitudinally and laterally to stay in phase and keep the upper frame level.

Abstract: The present invention pertains to extension arm apparatuses that are adapted to support user devices throughout a range of positions. A given apparatus may include one or more arms that position the user device remotely from a support position. An extension and retraction device such as a gas cylinder is received within each arm, and provides a force to support the user device as the arm is placed into a given position. A variable force clevis is connected to the extension/retraction device within the arm. The variable force clevis is connected to a pair of locations in the arm as well. As the arm moves, for instance up or down, the variable force clevis rotates within the arm and dynamically adjusts the force provided by the extension/retraction device. Removable and/or pivotable covers are provided for managing cables of the user device attached to the extension arm.

Abstract: A spring-loaded shelf for an existing beverage cooler, which obviates the need for a user to reach more deeply within the confines of the cooler for a beverage as the contents of the cooler become depleted. The spring-loaded shelf has a base, a platform pivotally attached to the base by two scissor-type linkages, and a lifting mechanism for selectively and automatically raising the platform with respect to the base upon the scissor-type linkages, as the weight of the beverages placed upon the platform gradually decreases. Use of the spring-loaded shelf prevents injury to the user while retrieving a beverage from the cooler, and also provides for increased accessibility and visibility of the contents of the cooler.

Abstract: A monitor having a monitor body and a base member supporting the monitor body includes a link member positioned between the monitor body and the base member, a base hinge connecting one end of the link member with the base member in a tiltable manner to control the link member to be tilted relative to the base member within a predetermined degree of angle, a monitor hinge connecting the other end of the link member with the monitor body in the tiltable manner, an assistant link member transmitting a tilting movement of the link member relative to the base member to the monitor body, a first torsion coil spring elastically biasing the base member and the link member in opposite directions when the link member is forwardly tilted relative to the base member, and a second torsion coil spring elastically biasing the link member and the monitor in opposite directions when the monitor body is forwardly tilted relative to the link member.

Abstract: The present invention is directed to a mounting device comprised of a base configured for attachment to a desired mounting surface and to secure a resilient connector extending away from a connector support. The resilient connector further comprising a flexible snubber and a spring surrounding the snubber. At least two alignment surfaces are provided, disposed around the resilient connector, where the alignment surfaces adjoining each other. The alignment surfaces may be disposed on an alignment loop, or a plurality thereof, disposed around the resilient connector.

Abstract: The present invention is directed to a mounting device comprised of a base configured for attachment to a desired mounting surface and to secure a resilient connector extending away from a connector support. The resilient connector further comprising a flexible snubber and a spring surrounding the snubber. At least two alignment surfaces are provided, disposed around the resilient connector, where the alignment surfaces adjoining each other. The alignment surfaces may be disposed on an alignment loop, or a plurality thereof, disposed around the resilient connector.

Abstract: To support and point a load on a support element, the pointing device having distinct link arms distributed around the load. Each link arm having a flexible element having a first end connected to the support element via a first hinge having a single degree of freedom, and a second end connected to the load via a second hinge having a single degree of freedom. The pointing device also having at least one movement transmission element disposed between the support element and the load to point the load relative to the support element.

Abstract: A bushing for use in a vehicle suspension system includes a pair of elastomeric bearings having cylindrical holes formed therein and flanges formed integrally therewith. The bushing further includes a journal carried by the bearings in the cylindrical holes. In the first embodiment, the bearings are of substantially elliptical cross section and provide a compliance in a major axis direction that is different than the compliance in a minor axis direction. In a second embodiment, the bearings additionally are formed with channels of partial substantially cylindrical section on the outer surfaces, thereby giving the bearings a compliance in the major axis direction of a nonlinear higher order than the corresponding compliance of the first embodiment. A third embodiment is similar to the second embodiment except that the bearings are formed with voids of a partial substantially conic section formed on the outer surface, with the apex of the voids being adjacent the flanges.

Abstract: An extended travel lift system including a support frame and a display device frame. First and second arms are connected at first ends thereof by a hinge connector. A second end of the first arm is pivotally attached to a first slide mechanism on the support frame and a second end of the second arm is pivotally attached to the support frame. Third and fourth arms are connected at first ends thereof by the hinge connector. A second end of the third arm is pivotally attached to a second slide mechanism on the display device frame and a second end of the fourth arm is pivotally attached to the display device frame. A biasing mechanism is provided to bias the display device frame to an extended position. A height control mechanism is provided to retain the display device frame in either a retracted position or the extended position. The first and second arms are typically located in a first plane and the third and fourth arms are located in a second plane parallel to the first plane.

Abstract: The invention relates to a stand having a pivotable support arm (2) and a balance weight (AG), in which the balance weight (AG) acts via a cable pull (24) for the weight compensation of the load (G), the balance weight (AG) being arranged in the area of the vertical upright column (21) of the stand.

Abstract: A stand for movable equipment has a first stand part and a second stand part that is movable relative to the first stand part and includes a pivot arm hinged to the first stand part and pivotable around a pivot axis. An energy storer provides weight equalization. The energy storer exerts a force on the pivot arm, by means of a deflecting element that is directed towards an abutment point on the first stand part. The pivot axis and the abutment point always define a vertical plane. The deflecting element is arranged on the second stand part.

Abstract: A vehicle seat suspension system is provided which includes, in a seat support comprising an upper housing and a lower housing and a scissors linkage support apparatus, a spring fixed to the upper housing and a cable attached to the spring and wrapping around a pulley attached to the upper housing and downwardly to an arcuate or eccentric pulley attached at the scissors linkage axis pivot and an actuator knob which allows a seat occupant to tighten or loosen the cable and raise or lower the seat to provide a vehicle seat suspension system. The present invention provides a suspension system which can be discreetly and infinitely adjustable and which allows a user to adjust the suspension curve characteristics of the seat by utilizing a non-circular drive pulley which is movably adjustable.

Abstract: A vehicle seat suspension system is provided which includes, in a seat support comprising an upper housing and a lower housing and a scissors linkage support apparatus, a spring fixed to the upper housing and a cable attached to the spring and wrapping around a pulley attached to the upper housing and downwardly to an arcuate pulley attached at the scissors linkage midway pivot and an actuator knob which allows a seat occupant to tighten or loosen the cable and raise or lower the seat to provide a vehicle seat suspension system.

Abstract: A shock absorbing suspension comprises a pair of parallel, spaced mounting plates (12), pairs of counter-rotating D-frames (13). Pair of frames is slidably attached to the inner side of the mounting plate 12' by two grippers 14 of the mounting plate 12 by two grippers 19. Resistance mechanism (65 and 66) are mounted on each gripper for substantially resisting the rotation of each individual frame in one direction only, such that the suspension will substantially resist being compacted together, but can be freely extended apart. In one application, the bottom mounting plate is attached to the ground, while the top mounting plate is attached to and supports a building. When at rest, the resistance mechanisms will provide enough resistance to allow the suspension to support the building without being compacted. When the ground jolts upwardly in an earthquake, the suspension will be compacted to absorb the upward motion of the ground. But, when the ground jolts downwardly, the suspension will freely extend.

Abstract: An equipment support structure capable of permitting the vertical arrangement or orientation of a damper spring to be readily carried out irrespective of the posture of setting of an equipment, A damper link which is pivotally moved depending upon the position of setting of an equipment is pivotally mounted at the proximal end thereof on one of the equipment and mount for supporting the equipment through dampers and a damper spring is provided between the damper link and the other of the mount and equipment for offsetting load applied from the equipment to the dampers and operatively connected to the damper ling so as to be pivotally moved in association with the damper link.

Abstract: A seat suspension system for supporting a seat support member on a base member includes support arms which cooperate with a spring suspension so as to suspend loads imposed on the seat. The support arms are connected to one of the seat support member and base member by a support mechanism. A cam element acts upon at least one of the seat support member and the base member and presents a cam surface offering a resistance to the motion of the accompanying cam follower which varies depending upon the height of the seat support member. The system preferably includes a height adjust mechanism for adjusting the unloaded distance between the seat support member and the base member. The height adjust mechanism may be either a ratchet mechanism which is operated by lifting the seat support member, or a spring assisted mechanism which is operable independently of the main suspension springs and which automatically biases an unloaded seat support member upwardly.

Abstract: A shock absorbing suspension comprises a pair of parallel, spaced mounting plates (12), two pairs of counterrotating D-frames (13), and two connecting bars (11). Each pair of frames is slidably attached to the inner side of one of the mounting plates by two grippers (14). The scissoring connecting bars are disposed between the pairs of frames to link the frames together. A resistance mechanism (65) is mounted on each gripper for substantially resisting the rotation of each individual frame in one direction only, such that the suspension will substantially resist being compacted together, but can be freely extended apart. In one application, the bottom mounting plate is attached to the ground, while the top mounting plate is attached to and supports a building. When at rest, the resistance mechanisms will provide enough resistance to allow the suspension to support the building without being compacted.

Abstract: Mechanism for movably supporting a load, comprises a fixed frame, a pendulum lever pivotally connected at one end to the frame, and a link pivotally connected at one end to the other end of the pendulum lever. The other end of the link is connected to a vertically movable load support. A gas spring is pivotally interconnected between the frame and the link at points spaced from the points of articulation of the link and pendulum lever to the frame and to each other. Provision is made for adjusting the position of the pivotal connection between the link and the gas spring lengthwise of the link, and for adjusting the position of the pivotal connection of the gas spring to the frame in a direction toward or away from the point of articulation of the pendulum lever to the frame. Guides for the load are provided, comprising rollers mounted on the frame in between which a vertical member slides vertically.

Abstract: A supporting structure for supporting a TV set on an armrest of a seat of an aircraft or other vehicle so that the TV set can be turned in a vertical plane between an operating position outside a cavity formed in the front portion of the armrest and a housing position within the cavity, can be turned about a vertical axis at the operating position, and can be tilted with respect to the vertical axis. The supporting structure includes a hinge mechanism provided at the front upper end of the cavity, and a turning mechanism supported on the hinge mechanism and supporting the TV set so that the TV set can be turned at the operating position in both horizontal and vertical planes. A hinge pin included in the hinge mechanism is provided at one end with a diametrical through hole expanding toward the opposite open ends.

Abstract: A suspension system for a wheelchair comprises a frame, a pivot bar mounted to the frame through a hinge point, and a seat mounted on the pivot bar. The pivot bar is supported from the frame by a shock absorber and a helical spring so that impacts transferred to the frame through the wheelchair wheels are partially decoupled from the movement of the seat. The movement of the seat is constrained in a single plane along the longitudinal axis of the wheelchair.

Abstract: An anti-earthquake structure insulating the kinetic energy of earthquake from buildings, which is constructed between a building and the construction site thereof, including a plurality of supporting layers having multiple ball seats, plural ball members correspondingly disposed on and pressed between said ball seats with extremely small rolling friction thereagainst, and a plurality of sliding block linkages disposed between the building and the supporting layers, whereby horizontal displacement of the construction site can apply no horizontal force to the supporting layers, and consequently, the building will remain stable and rigid, the sliding block linkages further converting vertical wobbling force into horizontal force, permitting the horizontal force to be absorbed by multiple buffer springs via lever devices.

Abstract: An apparatus for supporting an object on a base for isolating the object from movement of the base, typically an art object, instrument, case, or housing for projection during seismic activity. The apparatus includes a base plate for attachment to the base, with a frame positioned on the base plate and adapted for omni-directional movement over the base plate. A lever is pivotally mounted on the frame and is connected to a spring, typically by a cable. The lever is also connected to the base plate, typically by another cable, with movement of the base plate moving the lever and extending the spring, after which the spring retracts, restoring the apparatus to the rest position.

Abstract: A pedestal carrying a television camera and its accessories has constant-torque springs which are housed in a detachable housing. The output shaft of each constant-torque spring is made responsive to the weight of the camera and its accessories, and is connected via a reduction mechanism with a mechanism for winding up a line such as wire.

Abstract: Horizontal pneumatic shock absorbers are connected through gears and levers to convert the longitudinal control of the shock absorbers to vertical control of seat frames of vehicles. Particularly, a preferred embodiment of a resilient support has sufficiently low height to permit placement of the support between the seat and the frame of a motorcycle for supporting the seat at a normal level. The preferred embodiment has, in addition to a pneumatic shock absorber for support, a shock absorber applying an opposing force for controlling bounce. Also, spring couplings connect the levers for supporting the seat to provide resilience for cushioning rapid shocks of moderate intensity while the shock absorbers function more flowly for longer excursions.

Abstract: A tractor seat of the type having a seat pan 14 which is hooked on to a vertically movable spring biassed carriage 12, so that the seat pan can be released and moved out of the way of a standing driver, has a latch device 18 comprising a headed pin 20 secured to the pan 14 and a catch plate 22 secured to the carriage and formed with an aperture 22a for receiving the headed pin 20. The catch plate is resilient so that it can be bent away from the pin to release the seat pan. In particular the aperture tapers from the lower end normally occupied by the pin to an upper end through which the head of the pin cannot pass, so that accidental lifting of the pan will lock the headed pin within the aperture.

Abstract: Horizontal pneumatic shock absorbers are connected through gears and levers to convert the longitudinal control of the shock absorbers to vertical control of seat frames of vehicles. Particularly, a preferred embodiment of a resilient support has sufficiently low height to permit placement of the support between the seat and the frame of a motorcycle for supporting the seat at a normal level. The preferred embodiment has, in addition to a pneumatic shock absorber for support, a shock absorber applying an opposing force for controlling bounce. Also, spring couplings connect the levers for supporting the seat to provide resilience for cushioning rapid shocks of moderate intensity while the shock absorbers function more slowly for longer excursions.