Safety Binding for a Snowboard

Abstract

The invention relates to a safety binding (1) for a snowboard, particularly a safety binding to be attached in pairs to a snowboard. The invention solves the problem of reducing force peaks on the lower extremities of the athlete, which, for example, in the event of a fall exceed a force value which can be set, and in this event also enabling a three-dimensional rotation of the lower extremities. This is achieved in that a lower binding part (2), which can be fixed to the snowboard, and an upper binding part (3), which can be fixed to the shoe, are disposed on mutually facing support surfaces in a sliding manner, wherein the support surfaces are designed as the surface elements of two spherical caps, the common center of curvature of which is located above the lower binding part. The safety binding comprises at least one elastic connecting element (5), which is engaged in both binding parts and dimensioned such that it generates a physiologically allowed restoring force during the deformation thereof as a result of a displacement of the upper binding part out the normal position.

Description

The invention relates to a safety binding for a mobile piece of sporting equipment, in particular a safety binding which can be pairwise mounted on a snowboard.

A safety binding for releasable attachment of a shoe on a piece of sporting equipment, such as a snowboard, has the function to transmit, on one hand, steering forces from the athlete to the snowboard and, on the other hand, to release when critical force values are exceeded in order to prevent injury in particular to the lower extremities. An almost lossless transmission of the steering forces from the athlete to the piece of sporting equipment must be ensured with a safety binding under normal movements (not relevant for injuries).

Compared to Alpine skiing, injuries of the ankle occur more frequently during snowboarding with soft boots. In particular, the injury of ligaments and bone structures in the ankle is caused by anatomically unfavorable rotations about all axes of the ankle and introduced force peaks. This injury pattern is generally known as snowboarder's ankle and occurs primarily after a fall. It has been observed that with more flexible snowboarding shoes the risk of injury in the event of a fall is greater with more flexible snowboarding shoes than with inflexible snowboarding shoe models. However, a flexible snowboarding shoe is preferred by the athletes in many areas of the snowboarding sport for performing specific techniques and tricks. Reducing the injury risk of the ankle by using stiffer snowboarding shoes is therefore not practical.

Several safety bindings are already known which are reported to be suitable, in particular, for snowboards. DE 39 25 164 A1 shows a binding with a lower binding part mounted on the piece of sporting equipment, on which an upper binding part is movably arranged, wherein the upper binding part operates as receiving plate for soles and includes shoe attachment means. The upper binding part is supported by a plurality of spring coils or in another, not further specified, manner on the lower binding part by way of a ball joint, whereby the shoe of the athlete can be tilted, commensurate with the corresponding load, in any direction about a predefinable angular range, but can also be deflected about an axis perpendicular to the snowboard surface. This binding has additionally a control body which actuates a release mechanism for the shoe attachment means depending on the position of the upper binding part, i.e., when a presettable force value is exceeded. The binding then releases, when actuated, simultaneously both shoes. Disadvantageously, in the event of an unintended actuation of the binding (hard snow conditions, landings after jumps, etc.), the force transmission between the athlete and the board is interrupted so that steering of the piece of sporting equipment can no longer be guaranteed. This can represent a risk for injuries. In addition, the binding already allows small rotation and tilt movements before actuating the binding. This would again interfere with or reduce the force transmission from the athlete to the board. In addition, the construction of the binding is relatively complex, making it expensive to manufacture and difficult to keep operational.

DE 39 18 939 A1 discloses a snowboard binding with a lower binding part mounted on a snowboard and an upper binding part fixedly connectable with the shoe. Both binding parts are movably connected with one another by way of several elastic tension means. The pretension of the elastic tension means is designed so that the upper binding part can tilt about the longitudinal and transverse axes of the shoe, wherein predeterminable force values are exceeded, and rotate up to about 10 degrees about the vertical axis. This solution reduces force peaks and prevents a complete separation of the binding parts from each other. The binding is also not actuated even for critical force values. Disadvantageously, no means are provided for adapting the pretension of the elastic tension means to the individual requirements of the athlete. The binding can therefore worsen the transmission of steering forces necessary for snowboarding even during normal snowboarding, and can therefore appear soft and spongy.

DE 29 510 981 U1 also discloses a relatively simple snowboarding binding which is rotatable and tiltable in all three three-dimensional axes as well as lockable in each tilt position. However, rotation and tilt movements are prevented during the run. In this solution, an elastic rubber ring can be inserted between the binding parts to increase the friction connection between the binding parts and lock them reliably in the preferred position. The impact-damping effect attributed to this measure is, however, quite rudimentary and is unable to protect the athlete from critical force values due to the minimum tilt angle achievable in the locked state of the binding.

DE 44 06 074 C1 discloses a safety binding for a mobile piece of sporting equipment, in particularly a snowboard, wherein an upper binding part affixable to a shoe can also not be released from the other binding part attached on the piece of sporting equipment after actuation, but is able to freely rotate about the vertical axis. However, excessive dorsal extensions and supinations are particularly known as injury mechanisms associated with the application of critical axial forces. However, the technical solution described in DE 44 06 074 C1 does not offer protection precisely from such risky rotation movements.

Based on this state of the art, it is an object of the invention to provide a binding for securing a shoe on a mobile piece of sporting equipment, in particular a snowboard, which particularly reduces force peaks at the lower extremities of the athlete. However, this reduction should only be realized when an adjustable force value (which may occur, for example, in a fall) is realized, while allowing a three-dimensional rotation of the lower extremities. The binding to be provided should therefore realize an optimal force transmission from the athlete to the board during normal coasting and reduce the risk of injury to the lower extremities in a crash, without releasing the foot from the piece of sporting equipment. By keeping both feet of the athlete on the piece of sporting equipment in the event of a possible actuation of only one binding, force values on the respective other foot should not be increased, which would be provoked by unfavorable lever relationships if only one foot were completely released from the piece of sporting equipment.

The object is attained with the invention by a safety binding having the features of claim 1.

The safety binding according to the invention enables a three-dimensional rotation of the lower extremities, but allows their movement only when a certain force value is exceeded. This is achieved by arranging a lower binding part affixable on the piece of sporting equipment and an upper binding part affixable to a shoe are slidingly arranged on opposing support surfaces. These support surfaces are formed as surface elements of two universal ball joints having a common curvature center located above the upper binding part. The safety binding according to the invention has at least one elastic connecting element in engagement with the two binding parts and dimensioned so as to generate a physiologically permissible restoring force during its deformation due to a displacement of the upper binding part from the normal position. The safety binding according to the invention also has at least one snap-in locking device which locks the position of the upper binding part relative to the lower binding part in a predeterminable normal position, as long as the actuating forces operating on the snap-in locking device are below a predeterminable threshold value. When the snap-in locking device is actuated, the limit stops arranged on the binding parts limit the movement range of the two binding parts relative to each other to a range compatible with the anatomical conditions.

The invention can be realized in different advantageous embodiments. Advantageously, for improving the driving characteristic and reducing force peaks, the safety binding is adapted to the anatomy of the athlete and the common curvature center of the contact surfaces of the binding parts is approximately at the height of the knee joint of the athletes standing on the piece of sporting equipment.

Another embodiment allows adaptation to individual situations of the athlete, wherein the snap-in locking device has at least one movable locking element arranged on a binding part, which is in engagement with a corresponding counter catch arranged on the lower binding part by way of an adjustable spring force. To allow the athlete to explore the driving conditions when the snap-in locking device is actuated, the snap-in locking device may be manually actuatable.

In another embodiment of the invention, the movement range of the two binding parts relative to each other is limited to a range that is compatible with the anatomical conditions while preventing the two binding parts from lifting off—e.g., during jumps—when the snap-in locking device is released, by arranging limit stops in the forward region of the lower binding part and the rearward region of the upper binding part, with the limit stops encompassing the respective other binding part in form of a hook.

The invention will now be described in more detail based on an exemplary embodiment with reference to the appended drawings.

It is shown in:

FIG. 1 a side view of the safety binding without straps and highback,

FIG. 2 a perspective view of the safety binding without upper cover, highback and straps,

FIG. 3 a perspective view of the lower binding part,

FIG. 4 a perspective view of the elastic connecting element, and

FIG. 5 a perspective view of the limit stops limiting the movement range of the two binding parts relative to each other.

The safety binding 1 illustrated in FIG. 1 enables a three-dimensional rotation of the lower extremities when a certain force value is exceeded. The lower binding part 2 is fixedly mounted on the snowboard with screws by way of a turntable. The lower binding part 2 has (see FIG. 3) a support surface formed as a universal ball joint with the radius R, on which the opposing support surface of the upper binding part 3, which is also formed as a universal ball joint with the radius R, is supported.

The common curvature center of the contact surfaces is located above the upper binding part 3, advantageously approximately at the height of the knee joint of the athlete standing on the piece of sporting equipment. The snowboard shoe is hereby secured on the upper binding part 3 in a conventional manner with conventional straps (not illustrated).

A snap-in locking device which locks the position of the upper binding part 3 relative to the lower binding part 2 in a predeterminable normal position is arranged in the safety binding. The snap-in locking device has at least one conical locking element arranged on the upper binding part 3, wherein the locking element is in engagement, due to the spring force of a spring element, with a corresponding counter catch arranged on the lower binding part 2 and formed as a recess 4a (see FIG. 3). When the conical snap-an element is pressed against the recess 4a in the lower binding part 2 by the spring force, the upper binding part 3 is held in an initial position, preventing a relative movement of the upper and lower binding part relative to each other when the binding state is not actuated. This ensures that the force transmission between snowboard and snowboard is not reduced under normal driving conditions. The lower and the upper binding part 2; 3 as well as the conical snap-in locking element are preferably constructed from POM (polyoximethylene), which is standard in the winter sports industry.

When a critical force value is exceeded, the spring force of the spring element is overcome and the conical snap-in locking element is displaced accordingly. The rotation of the upper binding part 3 and the snowboarding shoe attached thereto are then released. The snap-in locking device has a device with which the critical force value for actuating the safety binding can be individually adjusted to the weight of the snowboarder and his/her level of expertise. This can be realized, for example, by adjusting the pretension of the spring element. When actuated, the relative movement between the upper and the lower binding part is damped for reducing force peaks. This is realized with an elastic connecting element 5 (FIG. 4) which is in engagement with both binding parts and arranged in the region of the vertical axis, about which the two binding parts can rotate after the snap-in locking device is actuated. In the event of an actuation, the elastic connecting element 5 guarantees that the other binding part 3 is not completely detached from the lower binding part 2. The elastic connecting element 5 is preferably constructed as a cylindrical elastic body 5a, with mounting elements 5b arranged on its end faces, which allow the elastic connecting element 5 to be safely secured to the lower and upper binding parts 2, 3. As an alternative to a cylindrical shape of the elastic connecting element 5, other shapes and/or a combination of several elastic connecting elements 5 may be installed.

Increased dorsal flexion of the ankle is prevented by mechanically limiting the movement of the upper binding part 3 relative to the lower binding part 2. This limitation is attained by hook-shaped limit stops 6 (FIG. 5), which are arranged in the forward region of the lower binding part 2 and in the rearward region of the upper binding part 3 and which each encompass the respective other binding part. This approach prevents the upper binding part from becoming detached from the lower binding part in the event of an active vertical movement of the athlete (jump) and hence an unintentional release of the safety binding.

Claims

1. A safety binding for a mounting pairwise on a snowboard, comprising: a) a lower binding part (2) affixable on the snowboard and an upper binding part (3) affixable to a shoe, wherein the lower and upper binding parts have contact surfaces sliding against each other, with the opposite contact surfaces of the respective other binding part being supported on the contact surfaces,the contact surfaces of the two lower and upper binding part (2; 3) are formed as surface elements of two universal ball joints having a common curvature center located above the upper binding part (3),b) at least one snap-in locking device which locks the position of the upper binding part (3) relative to the lower binding part (2) in a predeterminable normal position, as long as the actuating forces acting on the snap-in locking device are less than a predeterminable threshold value,c) at least one elastic connecting element (5) in engagement with the two binding parts (2; 3) and dimensioned so as to generate a physiologically permissible restoring force during its deformation caused by a displacement of the upper binding part (3) from the normal position,d) limit stops (6) arranged on the binding parts (2; 3), with the limit stops (6) limiting, when the snap-in locking device is actuated, the movement range of the two binding parts relative to each other to a range compatible with the anatomical conditions.

2. The safety binding according to claim 1, wherein the common curvature center of the contact surfaces of the binding parts is located approximately at the height of the knee joint of the athlete standing on the piece of sporting equipment.

3. The safety binding according to claim 1, wherein the snap-in locking device has at least one movable locking element arranged on a binding part (2; 3), and wherein the movable locking element is in engagement with a corresponding counter catch (4a) arranged on the other binding part by way of an adjustable spring force.

4. The safety binding according to claim 1, wherein the snap-in locking device is manually actuated.

5. The safety binding according to claim 1, wherein—in a top view—limit stops (6), which encompass with a hook shape the respective other binding part, are arranged in the forward region of the lower binding part (2) and in rearward region of the upper binding part (3).