Patent Grant
7231729
This application is the U.S. national phase of international application PCT/US01/16768, filed May 23, 2001, which designate the U.S., the entire contents of which is hereby incorporated by reference
The present invention relates to a ski boot that allows bending about a transverse axis, and torsion of the rear boot portion with respect to the front boot portion about the longitudinal boot axis.
German patent DE-OS-3343077 discloses a sole for a sports shoe, e.g. ski boot, which becomes stiff upon exertion of an external force. The upper shell of the ski boot should be construed such that a force exerted by the lower leg can be directed via the shaft, ankle and heel portions into the ski. However, as to the technical features of the upper shell the mentioned DE-OS-3343077 is silent.
U.S. Pat. No. 5,746,016 discloses a ski boot with pivotable toe cap and shaft. The toe is designed to be movable during walking, but fixed during skiing. For this reason the upper shell comprises a transversal opening with a cover. A tongue integral with the cover extends below the shell. The tongue can be blocked by means of a lock biased with a spring. In the blocked position, which is selected for skiing, pivoting of the toe cap is not possible. For skiing the shaft as well as the toe cap are stiff.
WO-A-91/16957 relates to an improved set comprising a ski, a ski boot, ski binding and a fulcrum element. WO-A-91/16957 proposes to use a ski boot wherein the toe cap is pivotable with respect to the rest of the boot. In particular, the toe cap is connected to the rear part of the boot by means of a hinge. The fulcrum element is located along a central section of the ski between the front and the rear bindings. When the ski boot flexes or pivots, force is directly applied via the fulcrum element to a central section of the ski to cause the central section to bow under such force.
In recent times, telemark skiing has experienced a renaissance. As to the equipment, telemark skiing differs from downhill skiing in the ski bindings and boots used. In contrast to a downhill ski binding the telemark ski binding has no fixed heel binding, but allows lifting the heel portion so that the rear sole portion (17) is almost at 90° to the ski and the knee of the skier can touch the ski in front of the binding. Consequently, the telemark ski boot must have a very flexible and soft sole which has essentially no tendency to rebound. In addition, the ankle in the telemark boot is not fixed but moves forward and backward when the heel portion is lifted. A telemark boot is therefore very difficult to use when the heel is fixed to the ski.
It is therefore an object of the present invention to provide a novel ski boot which reduces stress to the skier's anatomy and allows a better control of the ski. Another object is to provide a ski boot which allows the skier to maintain a more natural position when skiing. A further object is to provide a ski boot which allows the skier to direct more force into the ski than with conventional boots. Yet a further object is for the ski boot sole to more closely mimic the bending and dynamic response characteristics of the ski directly under the ski boot sole. Yet another object is for the ski boot sole to absorb strain forces effectively and enable the skier to more functionally use the proprioceptive nerve endings in the soles of the feet to improve sensitivity for better balance and control. According to the invention a ski boot according to the descriptive or designating part of claim 1 is characterized in that
By the novel design of the ski boot a force triangle is created that directs all the forces exercised by the skier directly to the elastic bending portion of the sole under the metatarsal area of the foot. The elastic bending portion of the sole is activated in turn by the vibrations and bending activity of the ski. The elasticity of the sole can be designed to respond according to a specific dynamic response that complements the ski's bending and torsional dynamic response qualities. Another advantage of the novel ski boot is that due to the attachment of the lower leg to the rigid spoiler shaft, the ankle of the skier is braced securely to not flex or bend and the center of gravity of the skier can therefore remain in its most favored and athletically efficient position.
Advantageously, the shaft, heel and rear sole portions of the outer boot are made of essentially non-flexible or unyielding plastics such that the heel portion, shaft and rear sole portion form a rigid or essentially non-flexible assembly. This allows the user to apply more force and more directly into the ski than with conventional boots with pliable or yielding shafts. The shaft and spoiler supports the ankle and the lower leg in its strongest position with the stiffest possible support, while the sole bends and rebounds under the forefoot. When the ankle does not have to flex then the knees do not have to flex more than minimally either and therefore also remain in the strongest and most stable position, which can be demonstrated in x-ray motion video. In essence the invention moves the important flex elements from the ankle to the ball of the foot area and the metatarsal heads.
Advantageously, the elasticity of the elastic zone is such that the bent sole has a tendency to flex back and rebound into the neutral plane position. By flexing and rebounding in harmony with the ski the user is able to feel proprioceptively and to coordinate effectively with the ski's most favorable behaviors. Preferably, the elastic zone allows bending about a transverse axis in the metatarsals. This enables the foot to bend naturally while skiing as it does in walking and hiking boots. According to a preferred embodiment of the ski boot the elastic zone is designed such that in addition to bending about a transverse axis a precisely managed torsion of the rear sole portion with respect to the front sole portion about the longitudinal boot axis is possible. Substantial resistance to sole and shaft torsion is favored to the inside for the precise transferring of steering and edging forces from the lower leg shaft over the medial edges, while allowing liberal torsion over the outside edges to permit natural and dynamic alignment of the lower leg anatomy and control of balance at all times.
Advantageously, either the intermediate shell portion or the sole comprises a guide or deflection means for causing a torsion of the front and rear boot portions about the longitudinal boot axis when they are bent with respect to each other. By this means the forces exerted by the skier can be directed most effectively e.g. to the medial side of the ski in order to support edging when most needed in difficult snow and terrain. The guide means can be one or more transverse beams formed in the sole and/or one or more transverse cuts in the intermediate shell portion. The beams may extend at an angle to the longitudinal boot axis.
Preferably, the guide means are arranged such that the rear boot portion is deflected laterally relative to the front boot portion. This allows for a natural and dynamic alignment and adaption of the lower leg for maintaining balance and control. There may be flex cut adjustment or blocking means provided for insertion into the transverse cuts to limit or adjust the maximum relative flexing or reduction of the opening between the front and rear boot portions. This allows the ski boot to adapt naturally to the individual skills of the skier. The adjustment or blocking means can be plugs, bolts, retaining plates or the like. In order to prevent opening of the flex cuts in the intermediate shell portion, a connecting means can be provided for interconnecting shell portions located in front and behind the cuts or openings.
Advantageously, the intermediate shell portion extends from the front shell portion forming the toe cap to the shaft and preferably comprises an opening at least in the metatarsal area. An opening in the metatarsal area is a simple means for creating a boot whose front and rear shell portions are bendable relative to each other. Preferably, the opening in the outer boot shell extends from the instep towards the sole. The opening in the metatarsal area may be V-shaped, round or oval or can be designed as longitudinal cuts or slots. It is to be understood that the opening may extend even as far as to the shaft without compromising the advantages of the novel boot.
If cuts are provided in the shell, then they can extend from the instep in a curve forwards and downwards (curved cuts). Instead of providing an opening or cuts, the intermediate shell portion may be made of a flexible material which is foldable or compressible to allow as much as about 15 mm reduction over the metatarsals to allow the bending between the front and rear parts of the ski boot sole.
According to a preferred embodiment the elastic zone comprises an elastic, preferably removable insert. Alternatively, the sole may comprise in the longitudinal direction areas of different elasticity so that the desired bendability of the sole is achieved. Another embodiment provides that the elastic zone comprises a structurally engineered elastic inner shell reinforcement frame insert permanently embedded in the outer boot. The elastic frame insert may comprise an easily bendable corrugated section in the metatarsal area. Said corrugated section may be sandwiched between a flat upper layer and a flat lower layer which bond the corrugations to create the desired dynamic response and elasticity in bending and torsion. It is desirable that the range of bending motion downward is limited to a maximum 3 mm from the neutral plane of the sole and that at the same time the tendency for any bending motion upward is blocked. An adjustment system can be provided so that the bending motion of the sole can be regulated to about 3 mm according to the skier's weight and ability level.
Advantageously, the outer boot comprises an inner shell frame that allows downward bending in the metatarsals while blocking tendencies to bend upwards. If a inner shell frame is provided, then the outer boot shell plastics can be thinner and flexible as the desired technical features are incorporated into the inner shell frame. The inner shell frame may be spoon shaped in the metatarsal area so that downward flexing is possible but upward flexing blocked. According to another embodiment the inner shell frame comprises corrugations in the metatarsal area that allows downward flexing but block tendencies of the boot sole to flex upwards. According to a still another embodiment the sole comprises a rigid leaf type spring imbedded in the sole plastic to allow a designated range of bending and dynamic response downward. The advantage of a leaf type spring is that its dynamic properties can be easily designed and controlled. It can be incorporated in the sole at a favorable price.
Preferably, the insert is designed as a flex and torsion box, or two opposing leaf springs, positioned under the imbedded reinforcing frame that is open at both sides of the sole to allow a designated amount of downward bending elasticity and blocked from upward bending, with the respective dynamic rebound response of both the top and bottom surfaces. Advantageously, the flex and torsion box connects the top and bottom surfaces of the sole with a vertical reinforcing I-beam membrane positioned in the sagital plane so that bending pressures on the top surface are transferred directly to bend the bottom surface to create a more effective bending and torsion box zone. This vertical I-beam or other effective material and shape can be snap fitted into position when desired and avoids deformation of the torsion box when flexing, retaining the optimum strength and dynamic properties of the torsion box. Other torsion box adjustment inserts, such as blocks made of assorted material properties, can also be used.
Another embodiment of the sole provides that the reinforcement of the torsion box insert may be designed such that the superior surface closest to the metatarsal bones is thinner and flexible, while the distal surface is made completely rigid to resist all bending forces. In this embodiment just the front and rear shell portions pivot relative to each other but not entire sole itself. The properties of the insert may be premolded with assorted dynamic response qualities. Although the insert is preferably integrated into the sole of the shell it can also be molded into detachable toe and heel walling sole plates, that are attached to the shell's sole, e.g. by screws or snap-fitted over respective retainers molded into the shell's sole.
According to a preferred embodiment the outer boot comprises an inner shell frame extending in or on the sole and also upward to form a part of the heel and ankle shaft. This design has the advantage that medial and lateral flexibility, and torsional rotations of the lower leg can be managed intentionally by design. Advantageously, the inner shell frame comprises on the medial side a shaft that extends a designated height above the medial and lateral ankle bones, and wraps around the heel area as an interconnected and stabilizing heel counter. Thereby the desired control of both medial and lateral shaft torsion, and the respective internal and external control of the lower leg shaft torsion when edging and steering the skis can be achieved. Preferably, the sole, rear and front shell portions are made from one piece.
Advantageously, the sole comprises a detachable lower sole. The lower sole can incorporate the desired flex and torsion characteristics so that the qualities of the ski boot sole can easily be altered according to the skier's weight and ability. Although the lower sole can be made in one piece, the detachable lower sole is preferably made in at least two separate portions, namely a toe and a heel portion. Said portions may be attached and secured to shell's sole by screws, bolts, snap-on connections and the like.
Like conventional boots the ski boot according to the invention can comprise an outer boot shell, preferably made of an unyielding plastics, and a soft inner boot or lining. Preferably, the inner boot is removable or retractable from the outer boot.
In order to provide a good hold of the ankle in the ski boot, ankle fixing and attaching means are provided which extend from the medial (inner) side of the outer boot to the lateral (outer) side and embrace and pull the ankle and heel of the skier back into the heel portion of the shell and inner boot. Preferably, flexible and essentially non-stretchable strap means are used as fixing and attaching means. The closures may be any of the known closure means known in the art. Advantageously, the ankle fixing and attaching means are arranged at an angle greater than 120 degrees, preferably at an angle between 130 and 145 degrees with respect to the sole for pulling the ankle of the skier's foot back into the heel portion.
According to a preferred embodiment of the invention the first or top lower leg fixing and attaching means are flexible but essentially non-stretchable strap means attached to the spoiler of the shaft. Said first strap means can be a part of the outer boot shell plastics or separate textile or plastic straps. It is of importance that the first strap allows to couple the inner boot and leg shaft effectively and with minimal or no play to the outer boot shaft or spoiler. The top lower leg strap may extend inside the outer boot shaft for embracing the inner boot and lower leg shaft directly with no outer boot shell plastics between strap and inner boot shaft. Preferably, the top leg fixing and attaching means are attached or fixed to the shell shaft spoiler a short distance from the top of the shaft end for coupling the upper inner boot and lower leg shaft end with a minimal or no play between the shaft and spoiler, respectively. This ensures that a maximum momentum can be applied to the elastic zone through the rigid shaft and spoiler portion. There may be provided second and third lower leg fastening and attaching means in the shaft portion which can be part of the outer boot shell plastics. Advantageously, foot fastening means are provided in the metatarsal region of the outer boot. Advantageously, foot fastening means are provided in the metatarsal region of the outer boot for user friendly adjustability.
It is of importance that the instep portion of the outer boot above the ankle fixing and attaching means is compressible or yielding so that the ankle can effectively be embraced by the ankle strap means. Flexible and elastic strap means have the advantage of adapting more readily to variables in foot volumes, shapes and adaptive activity, while also allowing for natural motions without losing support or control.
Object of the present invention is also a ski boot characterized in that the sole of the outer boot is made of an essentially rigid material, preferably plastics, comprising an elastic zone in the metatarsal region of the sole dividing the sole into front and rear sole portions; and an intermediate upper shell portion is provided between the front and rear shell portions of the outer boot, which is designed such that front and rear shell portions are bendable or pivotable with respect to each other, and wherein the front sole portion and the shaft are interconnected by at least a cable extending from the boot shaft to the front sole portion. By this design the elastically bendable toe cap is coupled with the rigid shell spoiler shaft so that forward knee motions that activate the force triangle cause increased tension of the cable and immediately increase both the sole's resistance to bending and it's rebound rate, and proportionately to the amount of forward motion force applied by the skier. The same effect occurs when the bending and vibrational forces of the ski activate the sole and the cable tension respectively. Preferably, tensioning adjustment means are provided for the selected tensioning of the cable. Tensioning means can be a lever, knob or the like which cooperate with one end of the cable. Advantageously, the cable extends in grooves provided in the sole.
Yet another object of the present invention is a system comprising a ski boot, as described above, a ski, and a ski binding comprising front and rear binding parts for receiving and fastening the front and heel boot portions, i.e. toe cap and heel of the boot. Advantageously, an replaceable or adjustable elastic or spring-based suspension element is provided which is mounted under the boot sole between the front and rear binding parts. The elastic suspension element assists the front and rear binding sole supporting platforms in transferring and absorbing the bending and vibrational forces from the ski to the boot sole, as well as from the boot sole to the ski, and help to amplify the tactile messages between the sensitive proprioceptive nerve sensors in the soles of the feet so that the skier may respond proactively and quickly to the constantly changing relativity between the skier, the skis and the snow surfaces. An adjustment screw system enables the skier to tighten or loosen the elastic or spring based suspension element to control the dynamic response and rebound rate of the elastic sole. The elastic suspension element assists the front and rear binding sole supporting platforms spacers in absorbing and transferring the bending and vibrational forces from the ski to the boot sole, as well as from the boot sole to the ski. This helps to amplify the tactile messages between the ski and the sensitive proprioceptive nerve sensors in the soles of the feet, so that the skier may respond proactively and quickly to the constantly changing relativity between the skier, the skis and the snow surfaces.
According to another embodiment of the system a curved leaf-type spring suspension element is mounted on the ski ahead of or under the front binding parts and behind the rear binding parts, by passing through hollow binding elevators, such that the curved spring element can cooperate with the boot sole surface when attached in the bindings. This is advantageous as the force exerted by the skier on the leaf spring suspension element effectively transfers forces from the skier ahead of and behind the bindings, for added influence over the skis, as well as working with the dynamic response of the sole in attenuating the high frequency vibrations and resonances that are generated and cannot be absorbed by the skis, and especially shorter length skis.
The invention will now be explained in further detail with respect to the drawings, which depict different basic concepts of the inventive ski boot. In the figures like parts are designed with like numerals. The figures show:
a and 17b: A further embodiment of a sole comprising a leaf spring system in neutral and unloaded position (a) and (b) loaded position;
a and 18b a sole system with a detachable sole portion in assembled (a) and disassembled position (b);
In the
According to the first embodiment shown in
According to a second embodiment shown in
According to a third embodiment shown
Common to all embodiments is that the shaft of the lower leg is coupled with the liner against the rear spoiler shaft 25, rear side shell portions 40, 42 and rear sole portion to form an essentially stiff ensemble so that a force triangle is created. The force triangle as schematically illustrated in
Although the shaft 25 may be made of one piece, the shaft 25 can comprise a cuff 37 being connected to the rear shell portion 21. Unlike conventional ski boots the cuff 37 of the novel ski boot is connected to the rear shell portion 21 such that rear shell portion 21 and cuff 37 are rigidly interconnected. Reference numeral 50 designates the spoiler extending above the shaft 25 and/or cuff 37, respectively, at their rear side. By way of example, the cuff 37 can be fixed to the rear shell portion 21 by at least two rivets 46 on both sides of the boot. The more rivets 46 that are used to fasten the cuff 37 to the shell shaft 25 the more supportive and rigid the shaft 25 and cuff system 37 become. The rivets 46 can be selectively added or withdrawn on either side of the cuff and shaft to create the desired amount of resistance torsion to the medial and lateral sides respectively and according to the skier's preferences. The rear shell portion 21, shaft 25 and the cuff 37 are designed such that they are in a rigid relationship to more effectively brace the ankle from forward flexing motion. By this means the skier is able to introduce a force directly into the elastic zone of the sole 13 via the boot shaft 25. If the skier exerts a force on the shaft parallel to the boot axis by bending forward with the knee, then a vertically downward directed force component (arrow 26) results in the bending of the metatarsal sole region. This effect is illustrated in
For an optimum control it is of importance that the lower leg and ankle of the skier are attached to the shaft 25 with a minimum play by pulling the leg shaft back and fastening it against the spoiler with the power strap, before the cuff is closed with the closure fastening system. Until now the cuff closures were closed first and before the power strap, which was then closed on the outside and in front of the cuff. For this reason it is preferable that the outer boot is easily deformable or compressible at the instep and metatarsal portion 29. In order to achieve this the opening 31 of the rather hard outer shell plastics preferably extends to the shaft 25 so that an ankle fastening means, e.g. a strap 39, extending from the inner side of the boot to the outer side can embrace and more effectively pull the ankle and heel of the skier back into the heel portion 23. The ankle of the skier is thereby essentially immobilized—unlike in conventional boots where the adaptability of the shell plastics is noticeably limited and often not effective in pulling the ankle and heel back into the heel portion. As the sole of the ski boot 11 can bend, there is also no tendency of the skier's ankle and heel to move forward or backward.
A first lower leg or shaft fastening means, e.g. a strap 41, extending around the upper cuff or shaft portion is adapted to secure the lower leg of the skier to the shaft 25 with a minimum play. As can best be seen from
According to a fourth embodiment shown
The straps 39, 41, 43, 45 can be fastened to the outer boot by means of ordinary buckles 53 (
In
a and 18b show a leaf spring reinforcement insert sole with replaceable toe and heel walking sole plates that can be attached either by bolts or a plastic snap-on system that fastens onto premolded shell retainers. The replacement sole parts can also incorporate select dynamic properties to match the skier's weight and ability, and can also incorporate various degrees of sole angles relative to the horizontal plane to adjust easily for the biomechanical peculiarities of each lower leg alignment anatomy.
a and 17b show the leaf spring system in neutral and unloaded position (
In
In order to control the flex and torsion characteristics of the inventive ski boot, the outer boot shell may comprise an essentially rigid reinforced inner shell frame 77 (
In order to achieve the desired boot sole characteristics reinforcing beams can be provided within or on the outside of the shell sole (
Another embodiment of a boot sole uses 3 reinforcing beams 87a, 87b, 87c and siping cuts 89 in the beams 87 to allow downward bending at specific points in the beams, while restricting upward bending when the siping cuts are squeezed together. The beam 87a extends parallel to the longitudinal boot axis on the inner (medial) side of the boot sole 13. The second beam 87b extends from the outer side of the heel walking plate at an angle to attach to the center of the longitudinal boot axis to the toe walking plate 97. The beam 87c extends a distance from the toe walking plate 97 backwards under the midfoot region. The asymmetric beam arrangement controls the sole torsion of the rear boot portion relative to the front boot portion when twisting and edging motions are applied to the sole, and blocks twisting internally to allow more stability and control of the skis, and to allow more pressure to be applied onto the skis inside edges.
In
The tension bridge 107 can be engineered as a cam rod 121 with a triangular cross-section providing three tensioning positions (
Increased cable tension against the convex surface of the imbedded reinforcement frame, adjusts and increases the resistance of the sole 13 to bend—as well as—how far the sole can displace downwards and the sole's dynamic response, rebound or spring rate. This enables the skier to adjust the sole 13 according to weight, ability and energy level and the dynamic response performance of the skis.
The tension adjustment bridge can be inserted into a channel 117 through the side of the sole. This allows the cable to be positioned on one of several grooves of various depths to progressively increase the cable tension and thereby control the dynamic response of the sole flex.
Drawing 26 also shows a preferred system for sealing out snow and water from the flex slot between the buckles on the four buckle boot model. The material used is impermeable to snow and water, affected little by changing temperatures, and it is soft and flexes easily.
There may be more than one flex cut 91 in the instep portion of the outer boot shell. The embodiment of a boot shown in
As can be seen in more detail in
Determining the length or depths of the flex cut depends on the collective response of the shell plastic and inner frame reinforcements to the designer's desired sole flexing behavior. Generally, the longer or deeper the flex slot cut into the shell the softer and deeper the sole flex will become. Consequently, the sole flex can be adjusted by shortening the effective length of the flex slot. The shorter the length of the flex slot the “stiffer” the sole flex becomes.
Flex cut adjustment or blocking means, e.g. plugs, bolts or other inserts, can be provided for adjusting or limiting the maximum relative flexing of front and rear boot portions. According to a preferred embodiment the flex cut adjustment means comprises a longitudinal retaining plate 137 with a plurality of upwards extending plugs 138 with external retaining brims 139 arranged at a distance from each other (
In order to prevent opening of the flex cuts 91, e.g. when the skier is leaning backwards, the front and rear shell portions may be interconnected by non-stretchable connecting means 143, e.g. a strap, reinforced webbing or the like. By this means the most desirable edging and rotational supportive qualities of a normal ski boot are preserved, while the flex slot can close and reduce as desired. The connecting means 143 in the form of a reinforced webbing is attached to the upper front and rear shell portion by rivets or bolts 145.
When the medial aspect of the rear shell is connected to the toes of the lateral aspect of the shell by a transverse bridge 143 of reinforced webbing, the opening of the flex cut can be more effectively controlled (
The embodiment illustrated in
Common to all embodiments is that the webbing 151 or connecting means bridge the shell gap or flex cuts above the sole bending area. The webbing 151 may be riveted into position and even secured by buckle base plates 155 as shown in
The embodiments of
The ski, ski binding and ski boot system shown in
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US01/16768 | 5/23/2001 | WO | 00 | 6/7/2004 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO02/094047 | 11/28/2002 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20040211091 A1 | Oct 2004 | US |
