Abstract: The present invention relates generally to skateboard and caster devices. More particularly, in a manner the invention concerns both dual wheel and single wheel axle supports of trucks and casters having a suspension mechanism for absorbing shock. The suspension mechanism is uniquely designed to progressively increase suspension resistance as forces acting on the mechanism increase by elastically deforming an independent arm in a manner to contact another arm or structure thereby transforming the independent arm into a dependent arm that results in a progressive resistance to a load until the forces are terminally engaged into a resilient abutment. A novel alignment mechanism functions to maintain the skateboard steering function.

Abstract: A skateboard or longboard truck comprises a hanger and a baseplate assembly. A redesigned hanger, a large ball pivot, a load-redirecting pivot cup, a tapered kingpin and other improvements give the hanger a high kingpin ratio and a high angle of mechanical advantage, thereby improving the performance and turning characteristics of the truck.

Abstract: A track structure is provided with a bearing containing chamber having a pivotable attachment section composed of a recess which is formed in one of a support base or a rockable section and is open to the other; an operation section formed on the other of the support base or the rockable section and rotatably fitted in the bearing containing chamber; a pivot shaft section for rotatably supporting the operation section within the bearing containing chamber; and elastic blocks arranged in plural within the bearing containing chamber at equal intervals about the axis of the pivot shaft section, the elastic blocks holding the operation section at the neutral position and, when the operation section pivots to right and left, biasing the operation section in a direction in which the operation section returns to the neutral position.

Abstract: A skateboard or longboard truck comprises a hanger and a baseplate assembly. A redesigned hanger, a large ball pivot, a load-redirecting pivot cup, a tapered kingpin and other improvements give the hanger a high kingpin ratio and a high angle of mechanical advantage, thereby improving the performance and turning characteristics of the truck.

Abstract: An in-line roller skate has a boot for accommodating a person's foot, a frame connected to the boot, and at least two wheels connected to the frame at a mutual distance in the skating direction for rideable support of the boot. The frame has a first frame portion and a second frame portion, wherein at least one wheel is connected to each frame portion and wherein the first frame portion and the second frame portion are mutually movable between a riding position and a braking position.

Abstract: A skateboard truck comprising a hanger pivotably mounted to a base, the hanger having a central aperture extending through opposite sides and a kingpin passing through the hanger central aperture. The truck includes a first and second bushing received on the kingpin, a first bushing seat receiving a portion of one of the first and second bushings and a second bushing seat receiving a portion of the other of the first and second bushings. The first and second bushing seats have different wall configurations. The hanger may be mounted to permit the first bushing to deform, rotating the hanger with respect to the base to a degree when subject to a force offset from the axis of the kingpin. The hanger may be reversibly mounted to permit the first bushing to deform, rotating the hanger with respect to the base to a different degree when subject to the same force.

Abstract: A deck wheeled device is provided comprising a deck, a subframe connected to at least one point of the deck, at least one truck assembly connected to the subframe, at least one wheel connected to each truck assembly, and at least one spring connecting each truck assembly to the deck. A wheel is provided comprising a tire, two substantially symmetrical hub halves, and at least one bolt that connect the two hub halves together.

Abstract: An improved skateboard or roller-skate truck is disclosed containing a novel yoke, base, grommet, wheel and bearing combination which delivers high precision steering, advanced steering control and more precise wheel alignment. The truck comprises a base plate and a yoke having a body portion with an aperture through it. There is a bearing member in the yoke next to the aperture. A post is mounted in the base plate and extends through the aperture in the yoke. A novel resilient grommet with a bearing surface on its face is mounted on the post and engages the bearing member in the yoke to restrict arcuate movements of the yoke. A novel wheel bearing is also disclosed which incorporates paired ball bearing casings with bell-shaped members on the outside of each casing slideably meeting each other inside a skate wheel where the bells self adjust the bearings to accommodate imperfections in the bearing seat levelness, bearing seat spacing, axle diameter and axle straightness.

Abstract: Devices and methods for lowering the center of gravity of a skateboard, while maintaining the structural integrity of the deck are described herein. In some embodiments, a skateboard includes a deck, a pair of trucks, and a set of bearings and wheels. The deck can include a cutout configured to receive a portion of the truck. The trucks are configured to couple to a bottom surface of the deck and include a portion disposed within the opening of the deck.

Abstract: A truck assembly having a mounting plate with a first mounting bracket with a first arm, a second arm and a ridge; a cushion with a front surface that defines a concave segment, a rear surface that defines a notch that receives and seats the ridge, and a first lateral surface and a second lateral surface; an axle assembly having a wheel shaft and a truck support with a first cushion support arm and a second cushion support arm; and a swing pin releasably joining the cushion and the axle assembly to the first mounting bracket.

Abstract: A skateboard truck assembly comprising a base plate, a hanger, and at least one tensional and/or compressible member interposed therebetween that utilizes rotation of the hanger to at least partially and temporarily deform the tensional and/or compressible member, thereby creating zones of tension and/or compression within the tensional and/or compressible member and facilitating smooth, near frictionless, and efficient motion of the skateboard.

Abstract: Devices and methods of transport are disclosed. Various embodiments include structural aspects related to steering and changing the direction of conveyances including features which utilize leaning or shifting of weight as part of turning.

Abstract: A wearable device configured to selectively provide roller transportation includes a shoe configured to at least partially accept a foot of a user of the wearable device, the shoe comprising a foot interface surface configured for selective contact with a bottom of the foot, a wheel assembly configured to selectively roll relative to a ground surface in response to rotation of at least a portion of the wheel assembly about an axle that is substantially coincident with an axis of rotation, and a frame connected between the shoe and the wheel assembly, the frame being configured to selectively transfer forces between the shoe and the wheel assembly and the frame comprising a clearance plane vertically offset from the ground surface.

Abstract: A truck assembly having a mounting plate with a first mounting bracket with a first arm, a second arm and a ridge; a cushion with a front surface that defines a concave segment, a rear surface that defines a notch that receives and seats the ridge, and a first lateral surface and a second lateral surface; an axle assembly having a wheel shaft and a truck support with a first cushion support arm and a second cushion support arm; and a swing pin releasably joining the cushion and the axle assembly to the first mounting bracket.

Abstract: A skate device includes a footwear-type boot having a sole, two side wheels positioned on opposite sides of the boot, a cross-jacket, disposed on a front region of the sole, the cross-jacket comprising a side-by-side tube with through holes for receiving screws to fix the cross-jacket to the sole, an active displacement mechanism connected to the two side wheels, the active displacement mechanism comprising a chassis with a clamped shaft that mounts a transfer bar, shaped as a flat plate, to a main joint between two lateral joints, the lateral joints having a center displaced from the main pivot joint, and shock absorbers connected to the lateral joints.

Abstract: A wearable device configured to selectively provide roller transportation includes a shoe configured to at least partially accept a foot of a user of the wearable device, the shoe comprising a foot interface surface configured for selective contact with a bottom of the foot, a wheel assembly configured to selectively roll relative to a ground surface in response to rotation of at least a portion of the wheel assembly about an axle that is substantially coincident with an axis of rotation, and a frame connected between the shoe and the wheel assembly, the frame being configured to selectively transfer forces between the shoe and the wheel assembly and the frame comprising a clearance plane vertically offset from the ground surface.

Abstract: A truck assembly having a mounting plate with a first mounting bracket with a first arm, a second arm and a ridge; a cushion with a front surface that defines a concave segment, a rear surface that defines a notch that receives and seats the ridge, and a first lateral surface and a second lateral surface; an axle assembly having a wheel shaft and a truck support with a first cushion support arm and a second cushion support arm; and a swing pin releasably joining the cushion and the axle assembly to the first mounting bracket.

Abstract: A synchronized rotating wheel assembly for a recreational device having wheels is disclosed. The assembly includes a base plate having top and bottom surfaces, the top surface of the base plate adapted to be attached to a portion of the recreational device, a gear assembly joined with the bottom surface of the base plate, and first and second wheel assemblies respectively joined with the first and second interconnected gears. The gear assembly includes first and second interconnected gears, a mechanism for rotating the first and second gears in unison and in the same direction, and a bias spring mechanism for returning the first and second interconnected gears to a default position when the gear assembly is not under stress. The mechanism may include a third gear between the first and second interconnected gears or a belt having teeth that cooperate with both the first and second interconnected gears.

Abstract: A skateboard assembly and a skateboard having the same are provided. The skateboard assembly includes a truck and a frame. The truck includes a pivot that has two oppositely extending axial sections, and the frame includes a pivot hole, and a first segment and a second segment extending at two sides of the pivot hole, wherein the first segment and the second segment include an angle and each of the first and second segments has an end far from the pivot hole provided with an axle.

Abstract: A scooter is disclosed which positions a center of gravity of a rider toward the front the scooter so that the rider can more easily perform a 180 degree turn trick. Since the rider is positioned closer to the front wheel, it becomes easier for the rider to flip over the handlebars. Fortunately, the scooter reduces a moment arm that defines a deceleration moment to reduce the likelihood that the rider will flip over the front handlebars.

Abstract: A truck assembly having a mounting plate with a first mounting bracket with a first arm, a second arm and a ridge; a cushion with a front surface that defines a concave segment, a rear surface that defines a notch that receives and seats the ridge, and a first lateral surface and a second lateral surface; an axle assembly having a wheel shaft and a truck support with a first cushion support arm and a second cushion support arm; and a swing pin releasably joining the cushion and the axle assembly to the first mounting bracket.

Abstract: A drift skate includes a board and at least one frame which has a connection portion and a cushion installation portion which is connected to the top of the connection portion. Two rollers are respectively connected to the connection portion by two axles. At least two independent cushions are respectively connected between the cushion installation portion and the board by two bolt units. The cushions are functions independently and respond to the action of the board so as to absorb vibration and reaction force from the ground.

Abstract: A dually operable roller skate includes a sole member having a pair of rear wheels transversely rotatably secured to a rear portion of the sole member, a steering base steerably secured on a front bottom portion of the sole member, a pair of front wheels transversely rotatably secured on the steering base, and a looking device adjustably or detachably mounted on the steering base and releasably locking the steering base to the sole member to shift a steerable skating to a straightforward non-steerable skating.

Abstract: A scooter includes a deck assembly and a handlebar. The deck assembly includes a posterior portion and an anterior portion. The posterior portion is pivotally connected with a rear wheel. The anterior portion is pivotally connected with a wheel shaft. A pair of front wheels is pivotally connected with two opposite ends of the wheel shaft. The anterior portion has a first sliding slot. The wheel shaft has an engaging recess. An engaging member is sildably received in the first sliding slot to selectively engage with the engaging recess between first and second positions. The wheel shaft is fixed with respect to the anterior portion in the first position.

Abstract: A wearable device configured to selectively provide roller transportation, the wearable device including a shoe configured to at least partially accept a foot of a user of the wearable device, the shoe comprising a foot interface surface configured for selective contact with a bottom of the foot, a wheel assembly configured to selectively roll relative to a ground surface in response to rotation of at least a portion of the wheel assembly about an axle that is substantially coincident with an axis of rotation, a frame connected between the shoe and the wheel assembly, the frame being configured to selectively transfer forces between the shoe and the wheel assembly and the frame comprising a clearance plane vertically offset from the ground surface, and an attachment system for selective attachment of the shoe to the frame.

Abstract: A skateboard truck maintains truck geometry. The truck includes a support pin including a cylindrical end slideably engaging a cylindrical passage in a base plate, and a ball end residing in a socket in a hanger. A support pin bushing under the cylindrical end is compressible and both carries some of a rider's weight and holds the ball end in the socket providing a second pivot to the truck. The second pivot eliminates horizontal play of the hanger thereby facilitating consistent compression of the kingpin bushings and improved stability of the skateboard. Support pin travel allows off-center kingpin bushing compression for steering and improves shock absorption. Eliminating horizontal play allows lengthened kingpin bushings and use of the entire height of the kingpin bushings. The combination of kingpin bushing preload, and weight carried by the support pin, tends to equalize the compression of the top and bottom kingpin bushings improving stability.

Abstract: An improved skateboard or roller-skate truck and wheel bearing assembly is disclosed containing an axle bearing yoke, base, grommet, and wheel and bearing combination which delivers improved steering precision, steering control, and wheel alignment. A grommet in the truck includes a bearing surface on a face which engages a bearing member in the yoke and restricts arcuate movements of the yoke and wheels. The contours of the grommet are also unique and contribute to steering control. The wheel and bearing combination incorporates paired bearing casings with bell-shaped members in their ends which meet each other inside a wheel of the board or skate and self-adjust to accommodate imperfections in the bearing seat levelness, bearing seat spacing, axle diameter and axle straightness.

Abstract: A truck assembly comprises a baseplate including a pivot arm hole, a first kingpin hole and a spring holder. A wheel axle is couplable to a wheel on each end of the wheel axle. A pivot arm is inserted into the pivot arm hole of the baseplate. An axle housing has a first end, a second end and a second kingpin hole. The first end includes the wheel axle and the second kingpin hole, and the second end includes the pivot arm. A swingable kingpin includes a first portion and a second portion. The first portion swings relative to the second portion. A spring member is provided substantially parallel to the kingpin and is coupled to the spring holder of the baseplate and the first end of the axle housing.

Abstract: This invention discloses a set of interchangeable bushing seat inserts which can be removably attached to the bushing seat on a hanger in any skateboard type truck to allow for different set ups and create different feelings. By having different bushing seat insert options, the rider can “tune” or adjust the feel and handling of the truck for different riding styles or courses. The interchangeable inserts may be of different geometry/shape and size and once inserted into the bushing seat area, it forms a new base and side for the bushing seat area, thus affecting the base and side of the bushing seat area. The possibilities for geometric changes to the inserts are almost limitless. This invention is also directed to a modified skateboard truck with an enlarged bushing seat which allows for the insertion (by any practical means) of specifically shaped inserts which surround the bushing.

Abstract: A truck assembly having a mounting plate with a first mounting bracket with a first arm, a second atm and a ridge; a cushion with a front surface that defines a concave segment, a rear surface that defines a notch that receives and seats the ridge, and a first lateral surface and a second lateral surface that each include an opening to receive a cushion locking pin; an axle assembly having a wheel shaft and a truck support with a first cushion support arm and a second cushion support arm; each of the cushion support arms having a cushion locking pin opening; a cushion locking pin that can releasably engage the cushion locking pin opening; and a swing pin releasably joining the cushion and the axle assembly to the first mounting bracket.

Abstract: A truck assembly having a mounting plate with a first mounting bracket with a first arm, a second arm and a ridge; a cushion with a front surface that defines a concave segment, and a rear surface that defines a notch that receives and seats the ridge; an axle assembly with a truck support having a convex surface that seats in a socket defined by the concave segment and at least a portion of the first arm and the second arm; a swing pin releasably joining the cushion and the axle assembly to the first mounting bracket and adjustment members each having a first surface, a second surface, and a cushion arm. The cushion arm contacts a lateral surface of the cushion, where an adjustment nut attached to the truck support can be used to move the cushion arm of the adjustment member relative the lateral surface of the cushion.

Abstract: A truck assembly having a mounting plate with a first mounting bracket with a first arm, a second arm and a ridge; a cushion with a front surface that defines a concave segment, a rear surface that defines a notch that receives and seats the ridge, and a first lateral surface and a second lateral surface that each include an opening to receive a cushion locking pin; an axle assembly having a wheel shaft and a truck support with a first cushion support arm and a second cushion support arm; each of the cushion support arms having a cushion locking pin opening; a cushion locking pin that can releasably engage the cushion locking pin opening; and a swing pin releasably joining the cushion and the axle assembly to the first mounting bracket.

Abstract: A skateboard truck and hanger therefor, the skateboard truck including a base plate, a bushing support, and a hanger which is dimensioned for removable securement to the bushing support. The hanger is preferably removably secured to the bushing support by means of machine screws passing through openings in the bushing support for threaded engagement in threaded openings within the hanger.

Abstract: Skateboard designs including a hanger with a yoke with two arms, comprising a bumper which provides an increasing force as the wheel axles are pushed away from their resting position, and wide wheels with an asymmetrical and gradually tapering profile as the wheel extends outward from the midline of the board, for improved “surfing-like” maneuverability including an enhanced ability to “carve” like a snowboard.

Abstract: A skateboard with two wheels (11), said skateboard having a front plate (15) and a rear plate (16) which are connected with each other by a spring element (3), which is secured to a rod (1 and 2) at both ends of the spring element (3). The two wheels (11), the front plate (15) and the rear plate (16) are secured inclined (4) to the rod (8, 11) by means of screw connections (4, 12) to form an angle relative to the upper sides of the plates (15 and 16). In this manner, the front plate (15) and the rear plate (16) are protected against breaks, as the wheels (11) are not secured directly to the front plate (15) and the rear plate (16), but to the rods (1 and 2) with the spring element (13).

Abstract: A truck assembly for a vehicle such as a skateboard or scooter may have a kingpin about which a hanger rotates. The hanger may be biased toward a caming surface having a depressed configuration by a spring, weight of the rider and also via a centrifugal force created during turning. This aids in dynamically stabilizing the truck assembly and the vehicle to which the truck assembly is mounted based on the particular rider and the maneuver being performed on the vehicle. The caming surface may have a regressive configuration such that the spring compresses at a different rate per degree of rotation of the hanger.

Abstract: A triple action roller skate steering and suspension mechanism includes upper and lower cushions clamped on either side of a skate truck, plus a third action comprising a floating cushion mechanism supporting and surrounding the pivot cup portion of a pivot joint mechanism. A pivot pin is threaded into the skate truck and can be preloaded against the pivot cup and floating cushion mechanism, thereby providing improved shock absorbing, durability and adjustability. The roller skate base plate is a unitary structure including a hollow arch for lightweight structural reinforcement.

Abstract: A truck according to the present invention includes a hanger dimensioned for insertion of axles upon which wheels are attached. The truck may be configured for attachment to a skateboard. The hanger includes a cutout portion including a key cavity into which a key is positioned. Bushings and a kingpin are also installed onto the hanger. The key when positioned within the key cavity of the hanger confines the pivot of the hanger on a centerline which bisects the hanger. The key may include extending cylindrical tabs which may allow for the hanger to freely swivel about the kingpin passing therethrough without the use of bearing surfaces. The bushings are positioned on the kingpin and on opposite sides of the key and key cavity of the hanger so as to urge the hanger to its center position.

Abstract: An in-line roller skate having a shoe and a wheel supporting frame extending therefrom for supporting aligned wheels. The frame includes a main frame body mounted to the shoe and at least one auxiliary frame body for supporting a wheel and being pivotally mounted to the main frame body. A resilient and deformable member is interposed between the auxiliary frame body and the shoe. The auxiliary frame body is so pivotable as to provide for moving the wheel towards and away the shoe for a distance determined by the extension and compression of the resilient and deformable member.

Abstract: The present invention relates to a roller ski or board, said ski or board providing in-line central rollers, centrally provided on the ski or board body, and two pairs of additional rollers, respectively a front pair and a rear pair, said pair of rollers being raised with respect to the ground on which ski or board rests when the same ski or board is substantially parallel with respect to the ground, and contacting the same ground when ski or board is inclined, each one of the additional rollers is coupled with the ski or board by a support system comprising a fork, having one end coupled with the roller and the other one faced toward the ski or board, between the end of the fork faced toward the ski or board and the same ski or board being provided with a resilient element.

Abstract: A skateboard truck is fabricated utilizing one, or more, elongated, generally ‘wing’ shaped, elastomeric bushings which have the ability of being controllably rotated both from within, as well as from around, the perimeters of one or more bushing seats formed into the main body of the hanger of the skateboard truck. By controllably rotating the wing shaped bushing from a parallel bushing position in relation to the sloped mounting face of the truck base plate into a perpendicular bushing position in relation to the same sloped mounting face, an enhanced range of truck tension control options are provided to the truck. Such a truck design permits the possibility of bushing tension and position adjustments to be made to the truck without the need for the rider to dismount the skateboard, and also without the use of tools. Moreover, a skateboard rider has the ability to perform such truck tension adjustments while being mounted on and in the act of riding the skateboard.

Abstract: A skate suspension system is provided for reducing stress on a user's legs while skating. The system includes a chassis configured for coupling to a skate boot. A rear skate arm is pivotally coupled to a front skate arm. A medial shock is coupled to and extends between the front skate arm and the rear skate arm. A front wheel is coupled to the front skate arm and a rear wheel is coupled to the rear skate arm. The front skate arm is coupled to the chassis by a front support extending between the chassis and the front skate arm. Similarly, the rear skate arm is coupled to the chassis by a rear support extending between the chassis and the rear skate arm.

Abstract: A skateboard truck assembly providing improved speed reduction or braking response when the rider places the skateboard in a rear tilt or tail drag position without sacrificing the skateboard's turning responsiveness. The truck assembly comprises a pair of axle distal sections, the portion of the axle extending beyond the ends of the hanger, that are angled relative to the riding surface. The angled axle sections causes the wheels to move in an outward direction, relative to the forward direction of the skateboard, when the skateboard is placed in a rear tilt position, resulting in drag that slows or stops the forward movement of the skateboard. Preferably, the truck assembly utilizes tapered wheels having an outer circumference which is larger than the inner circumference to provide improved speed reduction and turning stability. In addition, the pivot axis is more closely aligned or aligned with the axle axis to increase turning stability.

Abstract: A turning mechanism for skateboards includes a plate fixed to the underside of the board and a wheel frame is pivotably connected to the pivot tube on the plate. A first part extends through a lug on the plate and a second part is threadedly connected to the first part. A U-shaped first restriction member extends through a spring and is connected to the second part, and two hook ends of the first restriction member are hooked to a first end of the spring. A U-shaped second restriction member extends through the spring and is connected to a rod on the wheel frame. Two hook ends of the second restriction member are hooked to a second end of the spring. The second part moves linearly to pull the spring when rotating the first part so as to restrict the required force that the wheel frame is pivoted relative to the pivot tube.

Abstract: A skateboard wheel truck assembly has a suspension including a non-circular base bushing with wings or arms extending laterally outwardly, providing for increased stability and control and reduction of wobble in use of the skateboard.

Abstract: A skate truck is disclosed which provides for a wide yaw angle for a hanger, minimal friction during yawing of the hanger, and a suspension that is dynamically stabilized based on a weight of a rider and a turn radius of a vehicle to which the skate truck is mounted. Additionally, a tension of the skate truck can be adjusted by preloading a spring which accommodates a wide weight ranger of riders. The truck may have a hanger supported between two bearings, namely, a sliding bearing system and a thrust bearing. The sliding bearings slide within grooves that define a pivot axis of the hanger. The grooves can also have various customized ramp profiles to provide a different feel during turning of the vehicle.

Abstract: A vehicle includes a chassis, a suspension system, and a steering system operably coupled to the chassis and to the suspension. The chassis includes a mounting member that has a first elongated slot. The suspension system includes a beam that is pivotally coupled to the mounting member. The steering system includes a first axle, a second axle, a tie bar that extends between first and second tie bar ends, and a slider. The first and second axles are pivotally coupled with respect to the beam. The tie bar is operably coupled to the first and second axles and includes a second elongated slot that is configured to overlie the first elongated slot. The slider is positioned in the first and second elongated slots, and is configured to move in the first and second elongated slots to select a ratio of the tilting of the mounting member to the steering of the first and second axles.

Abstract: A truck assembly for a vehicle such as a skateboard or scooter may have a kingpin about which a hanger rotates. The hanger may be biased toward a caming surface having a depressed configuration by a spring, weight of the rider and also via a centrifugal force created during turning. This aids in dynamically stabilizing the truck assembly and the vehicle to which the truck assembly is mounted based on the particular rider and the maneuver being performed on the vehicle. The caming surface may have a regressive configuration such that the spring compresses at a different rate per degree of rotation of the hanger.

Abstract: A skateboard truck is fabricated utilizing one, or more, elongated, generally ‘wing’ shaped, elastomeric bushings which have the ability of being controllably rotated both from within, as well as from around, the perimeters of one or more bushing seats formed into the main body of the hanger of the skateboard truck. By controllably rotating the wing shaped bushing from a parallel bushing position in relation to the sloped mounting face of the truck base plate into a perpendicular bushing position in relation to the same sloped mounting face, an enhanced range of truck tension control options are provided to the truck. Such a truck design permits the possibility of bushing tension and position adjustments to be made to the truck without the need for the rider to dismount the skateboard, and also without the use of tools. Moreover, a skateboard rider has the ability to perform such truck tension adjustments while being mounted on and in the act of riding the skateboard.

Abstract: A shock absorbing mechanism for a suspension skateboard truck and skateboard is disclosed. A suspension skateboard truck includes a hangar. The hangar has opposing axle sleeves that extend to opposite distal ends along a lateral axis defined by an axle channel formed by each axle sleeve. The distal end of each axle sleeve includes a cavity that has a width greater than a width of the axle channel. The apparatus further includes an axle extending out from the axle channel and cavity of the distal end of each axle sleeve, and a shock absorbing mechanism occupying each cavity at least partially around the axle.