Abstract: An individual movement equipment item, which is constituted by a pair of motorized skates, each of the motorized skates comprising: a plate in the form of a sole and having a front portion, which is articulated transversely relative to a rear portion, the plate having means for connecting to the foot or the shoe of the user, motorized means, which are formed by two portions, which are articulated transversely in order to form a front train and a rear train, connection means between the articulated plate and the motorized means, which connect the front portion to the front train and the rear portion to the rear train, characterized in that the angle of the longitudinal axis of the at least one of the trains of each of the skates forms an angle between 10° and 20°, and preferably of from 12° to 15°, with the longitudinal axis of the plate.

Abstract: A motorized or non-motorized multi-wheeled skateboard assembly including a board deck to support the user, a board having a top side, a bottom side, a flat and a rounded end, linkages, hinges, a steered wheel assembly, an input device and a drive assembly. The steered wheel assembly improves maneuverability, turn radius, and stability. The user steers the skateboard assembly by altering pressure between the top side first end and the top side second end causing the steered wheel to turn, thus manually steering the board. This change in pressure is also altered between the first linkage and second linkage in direct or inverse relation to altering pressure between the top side first end and the top side second end of the board deck.

Abstract: A device which may include first and second cross skate bodies each having a frame configured to support at least first and second wheels situated inline of each other, each frame having at least one compartment configured to position a corresponding power source of first and second power sources; first and second foot couplers, each foot coupler configured to couple a foot of a user to a corresponding cross skate body of the cross skate bodies; a first traction motor coupled to drive at least one of the first and second wheels of the first cross skate body; a second traction motor coupled to drive at least one of the first and second wheels of the second cross skate body; and a controller which may be configured to: receive a drive signal from a drive controller, and control the first and second traction motors to drive the corresponding wheels in accordance with the drive signal.

Abstract: A roller skate is equipped with three or four wheels arranged in one line on the carrier which is joined to the shoe. Each wheel is cushioned independently with a spring system including at least two compression springs. A front wheel can be provided with two springs the longitudinal axes of which are oriented in the extent between the horizontal and vertical directions with the bottom ends of the springs being placed in front of the top ends of the springs or under them. Other wheels may be equipped with four springs having the longitudinal axes of the spring oriented vertically. At least two wheels can be provided with a braking system including clips with brake pads on both sides. The roller skate may be used and maintained on a specially configured assembling stand.

Abstract: A structure of inline skates is provided, the structure of inline skates includes a cushion device, a wheel with an annular ratchet wheel on its side, and a pawl assembly. By using the user's weight to press down the structure of present invention, the wheel with the annular ratchet wheel on its side engages the pawl assembly, which stops the wheel with the annular ratchet wheel on its side from rolling in one direction, and the wheel with the annular ratchet wheel on its side can roll in another direction. Thereby, the structure of inline skates is more ergonomic and exercise injuries can be prevented. In addition, a brake is provided for providing shock absorption and as a fulcrum to make more powerful acceleration. Besides, automatic support upright is also provided for avoiding tumbles.

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: An apparatus for operating a roller up and down is provided, which includes a main body fixed to a bottom of a shoe, an operating body to which the roller is imbedded, which is slidably mounted within the main body, and an operating assembly to move the operating body within the main body between an operating position and a non-operating position, wherein the roller protrudes out from the main body in the operating position while the roller is retracted into the main body in the non-operating position. A wearer of a shoe is capable of shifting the shoe between an operating position in which the roller protrudes out from the bottom of the shoe and a non-operating position in which the roller is retracted into the bottom of the shoe, by a simple operation. Accordingly, the shoe can be used as a roller shoe when the roller is in the operating position, and used as a general walking shoe for everyday use when the roller is in the non-operating position.

Abstract: A polyurethane biasing mechanism, comprising a first surface contact area with a first mass having a durometer that provides a first resistance and a first rate of resistance responsive to application of forces. The biasing mechanism having a second surface contact area with a second mass having the same durometer that provides a second resistance and a second rate of resistance responsive to the forces. The first resistance and the first rate of resistance are different from the second resistance and second rate of resistance, a combination of which provides a rate of resistance that commensurately varies and is correspondingly responsive in relation to varying forces.

Abstract: The present invention relates generally to a structure of inline skates, which provides a cushion device, a wheel with an annular ratchet wheel on its side, and a pawl assembly. By pressing down the weight, the wheel with the annular ratchet wheel on its side engages the pawl assembly, which stops the wheel with the annular ratchet wheel on its side from rolling in one direction, and the wheel with the annular ratchet wheel on its side can roll in another direction. Thereby, the structure of inline skates is more ergonomic and exercise injuries can be prevented. In addition, a brake is provided for providing shock absorption and more powerful acceleration. Besides, automatic support upright is also provided for avoiding tumbles.

Abstract: A polyurethane biasing mechanism, comprising a first surface contact area with a first mass having a durometer that provides a first resistance and a first rate of resistance responsive to application of forces. The biasing mechanism having a second surface contact area with a second mass having the same durometer that provides a second resistance and a second rate of resistance responsive to the forces. The first resistance and the first rate of resistance are different from the second resistance and second rate of resistance, a combination of which provides a rate of resistance that commensurately varies and is correspondingly responsive in relation to varying forces.

Abstract: A polyurethane biasing mechanism, comprising a first surface contact area with a first mass having a durometer that provides a first resistance and a first rate of resistance responsive to application of forces. The biasing mechanism having a second surface contact area with a second mass having the same durometer that provides a second resistance and a second rate of resistance responsive to the forces. The first resistance and the first rate of resistance are different from the second resistance and second rate of resistance, a combination of which provides a rate of resistance that commensurately varies and is correspondingly responsive in relation to varying forces.

Abstract: The present invention is a shock absorbing tandem roller skate including a shoe or boot, a shoe plate secured to the shoe, at least one shock absorbing unit secured to the shoe plate, at least a first pair of wheels secured to the at least one shock absorbing unit, at least a second pair of wheels, a first brake unit for providing braking to the at least a first pair of wheels, and a second brake unit for providing braking to the at least a second pair of wheels. The shock absorbing mechanism of the at least one shock absorbing unit flex and absorb shock horizontally and diagonally in a simultaneous manner to provide a steering mechanism for the user. The present invention is also directed to skateboards and scooters that may utilize the shock absorbing technology of the present invention.

Abstract: An inline skate mounting a pair of air tubes is invented for absorbing shock transmitted to its wheels so as to allow the use of rigid wheels, and to protect the rider's knees and ankles from shock. The inline skate comprises a frame having insertion compartments for mounting the shock absorbers, guide recesses, brackets for defining desired spaces, and a wheel holder having supporting plates. The wheels are coupled to and supported by the sides of the supporting plate and inserted into the guide recesses so that the wheel holder moves upward and downward when an external force is applied so as to transmit the external force to the shock absorbers. The shock absorbers are inserted into the insertion compartments and filled with air to absorb the external force when the wheel holder moves vertically. Since the wheel holder moves vertically as the skate traverses an uneven surface, the inline skater can balance stably and safely.

Abstract: The skateboard wheel and axle assembly includes an axle rigidly mounted in a hangar, with opposite ends of the axle extending from the hangar. Each end of the axle has an axial blind bore defined therein closed by an end cap and a plurality of holes defined radially adjacent the end cap. A spring-biased detent pin slidably mounted in the bore urges a plurality of detent balls to partially extend from the radially disposed holes. The detent balls engage an annular groove defined in the inner race of the outer wheel bearing to retain the wheel on the axle. The detent pin has a release arm extending through aligned slots in the axle and the hangar that can be retracted, compressing the bias spring, in order to withdraw the detent balls from the groove so that the wheel can be pulled off the axle.

Abstract: An ice skate comprises a horizontal platform and a pair of opposing side brackets perpendicularly secured to an underside of the platform. A pair of opposing extension arms is pivotally engaged with each end portion of the side brackets, and an extender bracket is engaged with a center portion of the side brackets. Each extension arm has a torsion spring confined and arranged to enable the extension arm to pivot about the center axle within a certain range in tandem with the other of the pair of extension arms. A distal end of each extension arm has an axle non-rotatably engaged with a follower rotatably engaged in a vertical plane. Each follower is engaged with a horizontally elongated hole at front and rear end portions of the skating blade, and the extender bracket provides an additional follower engaged with a vertically elongated hole on a centerline of the skating blade.

Abstract: A truck includes a chassis attached to a deck of the skateboard, a yoke pivotally connected to the chassis and two wheels provided on the yoke. The chassis includes a rod extended from the underside thereof. The yoke includes a first portion, a second portion extended from the first portion, a third portion extended from the second portion so that the first and third portions thereof are biased and a rod extended from the upside of the first portion thereof. The wheels are provided on third portion of the yoke. A torque spring includes two ends located on opposite sides of the rods. One of the ends of the torque spring engages with the rod of the chassis while the remaining end of the torque spring engages with the rod of the yoke. Thus, the torque spring is loaded and tends to return the yoke relative to the chassis.

Abstract: An in-line skate includes a frame and two rolling gears. Each of the rolling gears includes two levers pivotally connected to the frame, two casters each attached to related one of the levers, at least one first cushion provided between the levers and two second cushions each provided between related one of the levers and the frame.

Abstract: A skateboard includes a deck with two connection members connected to an underside thereof the deck and two trucks are connected to the two connection members respectively. Each truck has a main body and a transverse tube, and two wheels are rotatably connected to two wheel frames connected to two ends of the transverse tube. A truck spring member is received in each main body and has a first recess with which a protrusion on each connection member is engaged. The truck is rotatable about a first pin extending through the main body and the truck spring members, and is connected to the connection member.

Abstract: A damper device for an in-line skate is provided, in which an impact caused by a non-uniform road surface during skating is absorbed and buffered in order to realize more stable skating. The damper device includes: a hinge member which is installed at the lower-front portion of a boot and the front portion of a wheel frame, and which is rotatably connected therewith; and a damper which is installed between a fixed bracket which is fixed at the lower-rear portion of the boot and which is extended down to the rear side of an ankle and the rear portion of the wheel frame.

Abstract: An in-line skate with a shock-absorbing device has a boot and a chassis attached under the boot. The chassis has a wheel frame, multiple wheels, a rear wheel bracket and a shock-absorbing device. The wheel frame has a middle and a rear end. The rear wheel bracket is pivotally attached to the middle of the wheel frame and extends toward the rear end of the wheel frame. The shock-absorbing device obliquely and pivotally attaches the wheel frame and the rear wheel bracket. Thereby, the shock-absorbing device significantly reduces vertical and horizontal vibrations and shocks by damping the rear wheel bracket with the shock-absorbing device. Since the pivoting rear wheel bracket has a length much shorter than a conventional pivoting wheel mount and is essentially a moment arm with regard to applied shock, the in-line skate is much more stable than a conventional in-line skate.

Abstract: The improvement of the pedestal of roller shoes, which is a technique in the field of sports shoes, provides the capability of shock absorption. The improvement of the pedestal includes the following features: the middle part of the joint shelf is mounted to the pedestal, a roller is mounted to the one end; the middle part of the spring steel plate is mounted to the appropriate place of the pedestal, the two ends of it mount to the other ends of the two joint shelves. This new design will absorb the shock imposed on the rollers via the damping of the spring steel plate, and prevent the shock from going to the feet of the user.

Abstract: In-line roller skate comprising a skate boot having an upper for enclosing and supporting a human foot; a chassis carrying a plurality of aligned wheels; and an outsole covering the bottom portion of the upper. The outsole has a heel portion with a cavity and an insert in the cavity for reducing shocks and vibrations transferred from the chassis to the human foot. The skate also comprises a resilient member mounted between the front portion of the skate boot and the front portion of the chassis.

Abstract: Shock absorbing quad and inline roller skates for use in traversing across rugged off-road terrain. The shock absorbing quad and inline roller skates includes a boot that has a foam-lining cushion for user comfort. A plurality of wheels that have an outer inflatable tire portion that is made of a puncture resistance material and a system for coupling the boot to the wheels with a plurality of shock absorbers.

Abstract: An in-line skate having a sports shoe connected to a frame supporting a plurality of in-line wheels. The sports shoe has a sole, and an upper made of soft material, and rigid protection strips. The protections strips are arranged above the lateral edge of the sole: at the lateral metatarsus region of the foot of the user; at the lateral heel region of the user's foot; and at the anklebone region of the user's foot.

Abstract: A skate is disclosed comprising a skate boot including an outsole and an upper for enclosing and supporting a human foot. The outsole comprises a resilient component insert for reducing shocks and vibrations transferred from the skating surface to the human foot.

Abstract: The upgraded structure of the pedestal of roller shoes, which is a technique in the field of sports shoes, indicates an upgraded structure of the pedestal of roller shoes with the capability of shock absorption. The following is its technical blue print: the middle part of the joint shelf joints to the pedestal, a roller is jointed to the one end; the middle part of the spring steel plate joints to the appropriate place of the pedestal, the two ends of it joint to the other ends of the two joint shelves. This new mode will absorb the shock burdened by the rollers via the transmutation of the spring steel plate, and prevent the shock from going to the feet of the user through the pedestal directly; it will improve the comfort degree during the usage and release the tiredness feeling of the user.

Abstract: An ankle support, particularly for in-line skates, which includes a base support that wraps about the users heel and a spaced upper support which wraps about the user's leg. The upper and base supports are fixedly joined by a plurality of struts. At least one stop secured to either the upper support or the struts abuts a stop on the base support to provide a hard stop for maximum braking.

Abstract: A roller skate includes a boot, a connection frame fastened to the outsole of the boot, an expandable frame fitted with the connection frame, a wheel frame fastened to the connection frame and provided with a plurality of wheels and a brake shoe, and an elastic member located in the connection frame by the expandable frame. The elastic member serves as a shock absorber of the roller skate.

Abstract: A vehicle truck for supporting a ground contacting device, and an independent-suspension turnable skate vehicle truck which supports a wheel or wheels or a runner or ski, and a boot having in-line wheels or tandem wheels is provided. The independent-suspension turnable skate vehicle truck has one or more deflecting beams attached to a wheel axle hanger and the opposite end attached to a skate vehicle mounting structure. The deflecting beam has at least one horizontal component and/or at least one vertical component. The vertical components resist vertical deflection of the wheel axle hangers to restrict upward and downward movement of the wheels or other ground contacting portions. The horizontal component controls most twisting motions controlling turning of the deflecting beam and wobble of the wheel. The truck and mounting surface are adaptable to permit changes to the number of wheels or ground contacting portions, the position of the wheels, and the thickness of the wheels.

Abstract: A skate frame (20) for an in-line skate (18) having a shoe portion (22) and a plurality of wheels (24) capable of traversing a surface. The skate frame includes an elongate structural member comprised of a structural material having a first average density. The structural member having first and second sidewalls (62 and 68), each having an upper end and a lower end. The structural member also includes a shoe mounting portion (50) spanning between at least a portion of the upper ends of the sidewalls. The first and second sidewalls having a wheel load introduction portion (58), wherein loads associated with the wheels are transferred to the structural member. The shoe mounting portion having a shoe load introduction portion, wherein loads associated with the shoe portion are transferred to the structural member.

Abstract: The present invention provides a suspension system for in-line skates. The in-line skate includes a boot and a tracking system attached to the sole of the boot. Opposing rocking arms that hold the wheels are connected to the tracking system using a truncated axle. In addition, an adjustable spring can be configured between the opposing rocker arms.

Abstract: A roller skate includes a wheel housing having two front and two rear panels each of which has one or more oblong holes. Two seats are secured to a shoe, and each has two plates slidably engaged onto the panels with one or more conduits or tubes which are slidably received in the oblong holes of the panels for preventing the seats from moving laterally relative to the panels. A barrel is disposed on the wheel housing, a sleeve is disposed on the rear seat and slidably engaged onto the barrel, and a spring member is stably received between the sleeve and the barrel.

Abstract: A skateboard comprises a board, front and rear wheel bases respectively mounted to front and rear portions of an underside of the board, and front and rear axles respectively attached to the front and rear wheel bases. The front axle has a portion abutting against the front wheel base such that the front axle pivots toward a loading point when a load is applied to the loading point not locating on a central longitudinal axis of the skateboard. The rear axle has a portion abutting against the rear wheel base such that the rear axle pivots toward a loading point when a load is applied to the loading point not locating on the central longitudinal axis of the skateboard.

Abstract: The present invention relates to a means of transport, comprising: a frame least two contact members, such as skis or wheels, which am oriented parallel to the direction of forward movement and which are arranged with clearance away from and toward the frame hereon; and a balancing construction between the frame and the contact members for the purpose of preventing slanting of the frame. The balancing construction can herein comprise per wheel at least one compartment filled with fluid and the compartments of at least two of the contact members can be in direct open mutual connection for the fluid.

Abstract: This invention relates to a hub mounted shock absorber suitable for use in the wheels of in-line skates or other small wheel transportation devices such as scooters, street skis, etc. and to in-line skates utilizing wheels with such hub mounted shock absorbers. The hub mounted shock absorbers include an outer tube with an elastomer, preferably a low durometer elastomer between the outer tube and the axle of the wheel. The elastomer is prefereably sandwiched between the inner and outer tube with the axle passing through the inner tube. Openings may be selectively provided in the outer tube to further reduce the stiffness of the elastomer and flexure or other appropriate mechanism may be included which result in minimum stiffness for the shock absorber in the vertical direction only.

Abstract: A pair of shock elements mounted on the wheel bearing frame of an in-line skate and attached to a foot platform are configured so that the attachment points of the shock elements to the platform which move in a Z direction are prevented from moving in an X or Y direction from each other and from movement in a Y direction measured from a plane parallel to the plane of rotation of the wheels and from movement in a X direction from a line parallel to the axis of one of the skate wheels.

Abstract: An in-line roller skate propulsion device comprising a lever and a wheel frame having a top, a bottom, a plurality of wheel axle holes near the bottom, a pivot connection near the top for pivotally connecting the lever to the wheel frame, and a hole and shaft combination for connecting a resilient member. The lever's pivot connection is located forward of the center of the lever. As the lever rotates around its pivotal connection to the wheel frame, the resilient member is stretched. Upon release of the rotating force, the resilient member returns the lever to a point of contact with the wheel frame or a stopping piece attached thereto. This action allows a skater to achieve greater speeds than with regular in-line roller skates while exerting the same amount of energy.

Abstract: A vehicle truck for supporting a ground contacting device, and in particular to a independent-suspension turnable skate vehicle truck which supports a wheel or wheels or a runner or ski, for example a roller skate boot have in-line wheels or tandem wheels is provided. The independent-suspension turnable skate vehicle truck has one or more deflecting beams attached to a wheel axle hanger and the opposite end attached to a skate vehicle mounting structure. The deflecting beam has at least one horizontal component and/or at least one vertical component. The vertical components resist vertical deflection of the wheel axle hangers to restrict upward and downward movement of the wheels or other ground contacting portions. The horizontal component controls most twisting motions controlling turning of the deflecting beam and wobble of the wheel.

Abstract: A skate which includes a shoe having a first frame and a second frame for supporting one or more wheels. The first frame and the second frame, or the sole of the shoe, are articulated in a region which lies approximately below the metatarsus of the foot in order to allow better flexing. An adjustable fork assembly is also provided between the first frame and the sole and is adapted to force the planar arrangement of the shoe once thrusting has ended.

Abstract: A brake for an in-line roller skate consisting of a rubber block (4) fixed to the end of a rigid support (5) at the rear of the skate, and intended to brake the skate by rubbing on the ground. The rigid support (5) has at least one cut-out (13) into which a piece (14) of elastic or viscoelastic material is force-fitted. This construction has the effect of damping the vibrations which are due to the block bouncing along the ground.

Abstract: An in-line roller skate in accordance with this present invention includes at least four integral independent suspension system aligned under the chassis platform having all forks axles pivotally in forward motion and opposite direction from each other. The integral independent suspension system all parts and components are integrated in a body-frame, includes at least two independent shock absorber mechanisms in which the front shock absorber suspension mechanisms interconnects with the rear shock absorber secondary mechanisms, in which the rear shock absorber mechanisms support the pivotally forks axles and wheel system. The main chassis system supports the front brake and central rolling-brake. The integral independent suspension and the removable boot systems are interconnected with the chassis system trough a plurality of removable fasteners. The removable boot supports the front and rear anatomical-frame structure and the rear integral independent suspension support the main brake system.

Abstract: A shock-absorbing skateboard device has a main board, a downtube connected to the main board, a head tube connected to the downtube, a handle disposed on the head tube, a front wheel connected to the head tube, a rear wheel support frame disposed on a bottom of the main board, and a rear wheel connected to the rear wheel support frame. A shock-absorbing mechanism is connected to the rear wheel support frame. An adjusting mechanism is connected to the shock-absorbing mechanism.

Abstract: A skate is disclosed comprising a skate boot including an outsole and an upper for enclosing and supporting a human foot. The outsole comprises a resilient component insert for reducing shocks and vibrations transferred from the skating surface to the human foot.

Abstract: Inline roller skates are provided with independent suspension systems, separately suspending one or more of a plurality of wheels. The wheels are mounted rotatably on axles, and the axles are held nominally parallel to the sole of the boot. The suspension systems include guides that maintain the axles parallel to the sole of the boot even as the wheels and axles move vertically in response to bumps and other forces.

Abstract: A vehicle truck for supporting a ground contacting device, and in particular to a independent-suspension turnable skate vehicle truck which supports a wheel or wheels or a runner or ski, for example a roller skate boot have in-line wheels or tandem wheels is provided. The independent-suspension turnable skate vehicle truck has one or more deflecting beams attached to a wheel axle hanger and the opposite end attached to a skate vehicle mounting structure. The deflecting beam has at least one horizontal component and/or at least one vertical component. The vertical components resist vertical deflection of the wheel axle hangers to restrict upward and downward movement of the wheels or other ground contacting portions. The horizontal component controls most twisting motions controlling turning of the deflecting beam and wobble of the wheel.

Abstract: An in-line roller skate having a boot and a chassis, the chassis having a longitudinal bottom part on which are arranged a plurality of wheels equipped with rotating axles aligned along a reference plane, which is overlaid by a plate adapted to receive the sole of the boot, wherein the boot has an internal wedging element arranged at the bottom of the boot, in order to define the angular position &agr; of at least part of the foot relative to the plane by producing a height difference between the support plane of the heel of the foot and the plantar support plane at the level of the metatarsi.

Abstract: The present invention provides a suspension system for in-line skates. The in-line skate includes a boot and a tracking system attached to the sole of the boot. Opposing rocking arms that hold the wheels are connected to the tracking system using a truncated axle. In addition, an adjustable spring can be configured between the opposing rocker arms.

Abstract: The independent wheel suspension system of the present invention provides an optimal shock absorption in which the shock absorber is easily activated by the weight of the user to provide for an improved maneuverability of the movable structure. The system includes a truck for mounting on the movable structure, a swing arm pivotally connected to the truck for rotation around a horizontal axis between first and second limit positions, at least one wheel rotatable on said swing arm, a shock absorbent device to bias the swing arm in the first position and having a shock absorber and a guide, and a user accessible tension adjuster for adjusting the tension of the shock absorber in accordance with the desired stiffness for use or preference. The guide has a first end pivotally connected to the truck about an axis parallel to the horizontal axis.

Abstract: A skate having a fitting portion adapted to be fixed on the plate of a chassis supporting the gliding element for the practice of the so-called “aggressive” skating. The fitting portion includes a soft portion forming an upper, for a boot or low shoe, mounted on a rigid sole called the insole, a hard cradle adapted to receive the soft portion and formed of an integral shell cut at its front and lateral portion corresponding to the top of the foot and defining a sole adapted to be fixed on the chassis, from which extends, on the one hand, a heel stiffener capable of receiving a hinged rigid collar and, on the one hand, a protective band peripherally bordering the from and sides of the sole, in the extension of the heel stiffener, and an arrangement for assembling the soft portion on the hard cradle.

Abstract: A jump skate comprises a boot with a base attachment, a surface engager, and a link/spring mechanism, which uses large spring deformation to boost a skater in jumping. The link/spring mechanism comprises at least two links and at least one spring (coil or wound). The links and the spring(s) are made of metallic, synthetic, or composite materials. The link/spring mechanism is connected to the boot and the surface engager with pin joints in such a way that allows large relative displacement with zero rotation between the boot and the surface engager, which offers improved control of the surface engager for skate jump/landing. The spring(s) is installed in such a way that it deforms with relative displacements between the boot and the surface engager. Thus a skater can first store energy into the spring(s) by forcing the boot down towards the surface engager and then jump to release the energy for further height.