Ski bindings prevent ski injuries by releasing the skier's leg from rigid communication with the ski when forces deemed to be injurious are applied to the ski, as in a ski fall. Typically, rotation of the ski boot out of alignment with the toe of the ski occurs from pivoting movement of the toe binding. The toe binding is set to retain the boot in alignment with the ski until a predetermined force, and when a twisting or rotation exceeding the predetermined force occurs, the binding pivots right or left to allow the boot to fall out of the ski, presumably from a downed skier rolling or tumbling across the snow surface. The threshold release force, however, needs to be identified and calibrated in order to prevent premature release from normal skiing movements that mimic the harmful forces
A ski binding plate interfaces between a ski and conventional ski binding for providing an alternate release mechanism for injurious forces that can elude conventional ski bindings, specifically forces that tend to cause so-called Combined Valgus and Internal Rotation (CVIR) and Boot Induced Anterior Drawer (BIAD) injuries, both concerned with Anterior Cruciate Ligament (ACL) damage. Combined Valgus and Internal Rotation injuries commonly occur when a skier is excessively back-weighted, and is characterized by forces that force the knee into a valgus position combined with an internal rotation. Boot Induced Anterior Drawer injuries typically result from forces such as that incurred from an aerial maneuver (i.e. jump) resulting in a back leaning landing such that the rear tips of the skis contact first, and the skier's weight tends to “slap” the front tips down with substantial force. This action causes sudden rotation and pulling force to be transferred to the knee region of the skier. Configurations disclosed below accommodate and absorb such forces by a disengageable heel biased out of engagement by a threshold downward force to permit rotation about a double pivoted toe, and by a toe release biased for a predetermined upward force that permits hinged upward tow movement away from the ski.
Configurations herein are based, in part, on the observation that skiing focuses a substantial force on the skier's leg from the effective leverage based on the ski length. Unfortunately, conventional ski bindings suffer from the shortcoming that the safety release mechanisms are focused on rotation at the toe, and remain fixed in response to other forces, such as backweighting, which can also generate harmful forces. Accordingly, configurations herein substantially overcome the shortcomings of conventional bindings by detecting a backweighting situation that leaves the knee open to harmful twisting at the ankle/boot juncture, and allows an outward pivot of the heel around a toe pivot point. In contrast to conventional approaches that release the toe to pivot outwards, backweighting beyond a threshold force releases a restrictor holding the heel fixed, and allows the heel to rotate around a fixed toe pivot. Backweighting is sensed by relative displacement of the toe to the heel, and movement beyond a threshold resistance force releases the heel. Backweighting may also be sensed by relative displacement of the heel to the toe.
The ski binding plate is designed to reduce the number of Anterior Cruciate Ligament injuries in alpine skiers. Most ACL injuries occur when the skier is in a back weighted unbalanced position. The binding plate senses when the skier is in a back weighted position to activate an ACL saving mechanism. This binding plate absorbs the injurious energy through a lateral rotation of the binding plate about a point located underneath the toe piece of the binding. The energy is absorbed through a mechanical system that detects backweighting forces and selectively releases the heel to pivot outward at the toe point for relieving “twisting” forces that can cause ACL and other knee injuries. The energy absorbed can lead to injuries known as the Combined Valgus and Internal Rotation ACL injuries. After the system has absorbed all the energy it is capable of, the binding may release the boot from the ski if the injurious load is still present.
This binding plate also has the ability to absorb energy which may lead to Boot Induced Anterior Drawer ACL injuries. This is accomplished through a posterior rotation in the vertical direction about the heel of the ski binding.
Conventional, spring based release mechanisms tend to follow a progressive force/displacement curve, because the spring exerts increasing force as the displacement moves away from a rest position (either compression or extension). Thus, a spring based system requires the least amount of energy to begin responsive movement, and the required energy to continue the movement increases. Configurations herein exhibit a flat or inversely progressive force vs. displacement curve to avoid excessively high engagement or release threshold. Concerns over a low engagement threshold of a release mechanism often cause conventional approaches to set excessively high engagement thresholds. This engagement threshold must be reached before mitigation of the harmful force, but a progressive tension as with a conventional spring further increases the force that needs to be applied after the engagement threshold is reached. The inversely progressive curve continues displacement at a lower force than that required to initiate displacement.
Configurations discussed below, therefore, include a ski binding plate having a plate adapted to engage the ski binding, in which the plate has a heel end and a toe end, and a heel absorption mechanism is adapted to absorb excessive lateral pivoting force from the heel of a ski boot. A heel receptacle is adapted to engage the heel end, and a vertical displacement moderator biases the heel into engagement with a heel receptacle. A dual pivot engages the toe end of the plate for permitting both downward movement of the heel end and lateral movement of the heel end out of alignment with the ski. The lateral pivoting force corresponds to release of forces tending to result in Combined Valgus and Internal Rotation injury. In the example arrangement, the vertical displacement moderator is responsive to downward force from the heel end toward the ski, such that the downward force results from disproportionate backweighting of a skier, in which the vertical displacement moderator disengages the toe end from the toe receptacle based on a predetermined release force. The dual pivot is responsive to permit lateral outward displacement of the heel end upon disengagement of the heel end, such that the heel end is engaged with the heel receptacle when biased by the vertical displacement moderator (i.e. upward into engagement during normal skiing or at-rest situations). The vertical displacement moderator permits lateral movement once the plate is released from the heel receptacle, such as by downward heel force from excessive back loading. The vertical displacement monitor disposes the heel end into engagement with the heel receptacle and is adapted to selectively disengage the heel end upon a predetermined release threshold of force applied to the heel toward the ski. Depending on configuration, the vertical displacement moderator may be defined by an assembly of a spring, hydraulic, pneumatic, or resilient material adapted to provide the predetermined release threshold. In particular configurations, the vertical displacement moderator is adapted to exhibit a nearly flat, or decreasing, force vs. displacement response curve, in contrast to conventional spring tension release bindings.
The plate is adapted to engage a conventional ski binding at a toe and a heel end, in which the binding plate is secured to a ski boot such that release operation of the ski binding is not impeded. The plate further may further include a bottom plate hingedly attached to the top plate via a hinge disposed at a heel end of the binding plate, and the toe end is adapted to selectively disengage according to a predetermined force of the ski away from the toe end.
The foregoing and other objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
a-7c show an alternate configuration of the ski binding plate device;
a-8b show the restrictor in the configuration of
Configurations discussed below demonstrate an example configuration for illustrating the principles and techniques employed herein for a method and apparatus to mitigate ACL and other twisting and/or torsion based injuries resulting from backweighting distribution of a skier. The general principles illustrated may be implemented by various configurations without departing from the disclosed concept for heel based release responsive to backweighting force. Several example implementations are illustrative, as shown below.
In the general configuration shown in
During ski activity, the binding plate 110 experiences force within the skiabiltiy window 186. Forces increase until they reach the ski-ability threshold and cross into the adjustment window 187. At this point, the binding plate has begun displacement (as in
a-7c show an alternate configuration of the ski binding plate device 110. Referring to
a-8b show the restrictor in the configuration of
Once the toe 112 rises sufficiently such that the detent 248 clears the protrusions 246, the heel 114 is free to pivot outward around the pivot point 240. The restrictor 230 further includes a plurality of resistance arms 232, such that each resistance arm 232 is responsive to a direction of outward heel displacement. Resistance arms 232-1, 232-2 (232 generally) operate to provide gradually decreasing resistance to the outward pivotal displacement of the heel 114. In the example shown in
Upon sufficient displacement of the toe (upwards), the top plate 210 rotates to pivot the heel 114 outward as the plate 210 rises up on the pivot 240 but does not disengage a receptacle 244 on the underside of the top plate 210. As the plungers 234 compress the springs 235, the fulcrum 233 slideably engages the inside edge 237 of the resistance arm 232, thus allowing further displacement and outward pivot with less resistance. In effect, this would generate a curve in the force diagram of
Therefore, each resistance arm 232 has an engagement portion at a distal end 241 from a rotation point 239, such that the engagement portion is adapted for slideable engagement with the fulcrum 233 on the pivot plate 210, and a resistance portion 243 at a proximate end, the resistance portion 243 having a plurality of plungers 236, such that each spring arm 134 is configured for resistive engagement with an opposed plunger 236 on the opposed resistance arm 232.
The resistance arms 232 are configured to provide decreasing resistance to the outward pivot by the heel 114, such that the decreasing resistance results from a pin defining the fulcrum 233 sliding outward on the resistance arm 232 as the pivot around the toe 112 at pivot point 240 increases.
Configurations herein further define a method performed by the disclosed binding plates 110 and 210, in which a method for disengaging a ski binding includes disengaging a heel 114 boot portion for permitting an outward pivot of the heel boot portion upon detecting a back-weighting above a threshold force. The device detects backweighting by sensing displacement of the heel 114 boot portion relative to the toe 112, in which displacement is countered by resistive force defined by an injury threshold. Typically a spring, cable, or hydraulic mechanism provides tension or compression for resisting forces below the threshold force to avoid premature deployment. Upon backweighting forces attaining the threshold force, the device permits upward movement of the toe 112 responsive to the threshold force, thus releasing the heel 114 for outward pivoting around the toe pivot point 240. The device applies gradually diminishing resistance to the outward heel rotation, such that resistance diminished based on the outward distance of the toe. In other words, a relatively large twisting force is required to begin outward heel displacement, and a lesser force needed to continue outward pivotal displacement. This is because once the injury threshold is attained, further damage can occur if the twisting force on the knee is not abated.
While the system and methods defined herein have been particularly shown and described with references to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
This patent application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent App. No. 61/861,162, filed Aug. 1, 2013, entitled “SKI BINDING PLATE,” incorporated by reference in entirety.
Number | Date | Country | |
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61861162 | Aug 2013 | US |