FIELD OF THE INVENTION
- BACKGROUND OF THE INVENTION
The present invention is directed to bindings for gliding sports and, in particular, to bindings having a pivotable highback support.
Gliding boards, such as snowboards, snow skis, water skis, and the like, are well known in the art and in the sporting world. Generally, a rider is securely held to the gliding board with a binding that connects to the gliding board and generally to the rider's feet or boots. Various types of bindings have been developed to allow the user to engage the gliding board. The present disclosure is described with reference to the currently preferred snowboard binding embodiments, although the present invention may readily be adapted for other gliding board applications.
Typical prior art snowboard binding systems are generally categorized as either strap (or conventional) bindings that typically include a rigid highback piece against which the heel of the boot is placed and one or more straps that secure the boot to the binding, or step-in bindings that typically utilize one or more strapless engagement members into which the rider can step to lock the boot into the binding. For example, the strapless engagement members may engage metal cleats integrated into the sole of the boot. Strap bindings are the original and most popular type of snowboard binding and are adjustable, secure, and comfortable. Step-in bindings allow the user to more easily engage and disengage from the snowboard.
Both strap bindings and step-in bindings usually include a highback ankle support that extends upwardly from the snowboard, and is positioned to overlie the back of the user's boot. The back ankle portion of the rider's boot abuts against a curved forward surface of the highback, essentially providing leverage by which the rider can control the snowboard's heel edge. Alpine riders who need to perform high speed turns generally prefer a taller and stiffer highback for greater edge control, wherein freestyle riders generally prefer a shorter highback for better flexibility. The angle that the highback forms with the snowboard (or base plate of the binding) when the highback is pivoted to its rearward stop, referred to herein as the maximum forward lean, is important to the feel and control of the snowboard. Generally the maximum forward lean can be adjusted by the rider and will be set to a particular angle, depending on a variety of factors, including the type of snowboarding to be undertaken, the slope conditions, and the like.
Of course, the rider's ankles are important to controlling the snowboard and, in particular, the angular orientation of the snowboard relative to the snow about all three axes, and especially about the longitudinal axis. The human ankle is a complex system of connections between the lower leg and foot that comprises three separate joints. The first is the ankle joint formed between the lower ends of the tibia and fibula and the uppermost bone in the foot, the talus. This joint allows movement of the foot in dorsiflexion/plantar flexion (i.e., toe up and down). The second is the subtalar joint between the two largest foot bones, the talus and calcaneus, which allows inversion and eversion movement of the foot. The subtaler joint is located below the ankle joint. Finally, the transverse tarsal joint is composed of the talus and calcaneus bones on the back side and the navicular and cuboid bones on the front side. The subtaler joint permits abduction (toe out) and adduction (toe in) movement.
- SUMMARY OF THE INVENTION
The adjustability of the maximum lean angle requires that the highback portion of the binding be adjustable in the direction of dorsiflexion/plantar flexion of the rider's ankle. It is therefore desirable for the highback portion to pivot about an axis that is approximately coaxial with the rider's axis for dorsiflexion of the ankle joint. However, because the dorsiflexion ankle joint is located higher than the other joints in the ankle, snowboard binding designers have had to compromise in order not to interfere with the other ankle joints and the highback portion of prior art bindings is generally constructed to pivot about an axis that is well below the dorsiflexion ankle joint. The result is that the highback is not optimally positioned with respect to the rider's ankle over the design range of settings for the maximum forward lean position. The present invention is directed to solving this disadvantage of the prior art.
The present invention is directed to a binding for gliding boards such as snowboards, and includes a base plate that attaches to the board, a heel loop that attaches to a rearward portion of the base plate, and a highback that is pivotably attached to the heel loop. The highback provides support for the rider and facilitates moving the board generally about its longitudinal axis. By pivoting the highback, it can be set to any of a range of maximum forward lean settings to accommodate the rider's preferences. In the present invention, the highback pivots about a virtual axis that is approximately located to correspond with the natural axis of the rider's ankle for rotation in dorsiflexion/plantar flexion.
In an embodiment of the invention, the oppositely-disposed wings of the highback attach to the heel loop through a pair of elongate curved slots having a radius of curvature that is on the desired virtual axis.
In an embodiment of the invention, the curved slots are disposed in curved channels in the highback, and the highback is attached to the heel loop with attachment hardware including nut plates having curved portions that are adapted to slidably engage the curved channels.
In an embodiment of the invention, the rearward intermediate portion of the heel loop is curved, to approximately conform to curvature on the heel portion of the highback, such that the highback approximately nests with the heel loop.
In an embodiment of the invention, the binding further comprises an adjustable toe strap and an adjustable instep strap.
BRIEF DESCRIPTION OF THE DRAWINGS
In an embodiment of the invention, the heel plate and highback are formed substantially from a rigid polymeric material, and the heel loop is steel.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 shows a perspective view of an embodiment of a snowboard binding in accordance with the present invention;
FIG. 2 shows an exploded view of the snowboard binding shown in FIG. 1;
FIG. 3 shows a side view of the snowboard binding shown in FIG. 1, with the straps removed for clarity; and
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 4 shows a fragmentary, cross-sectional side view of a portion of the binding shown in FIG. 1.
Refer now to the figures, wherein like numbers indicate like parts. FIG. 1 is a perspective view of a snowboard binding 100 illustrating a currently preferred embodiment to the present invention and FIG. 2 shows an exploded view of the snowboard binding 100. It should be appreciated that the binding 100 includes certain general aspects in common with the commonly-owned U.S. Pat. No.5,727,797, to Bowles, which is hereby incorporated by reference in its entirety.
The binding 100 includes a base plate 102 that is adapted to be selectively attached to a snowboard (not shown) by conventional attachment mechanisms as are well known in the art—for example, with fastening hardware extending through apertures in an adjustment disk 101. The base plate 102 provides a platform for receiving the snowboard boot (not shown) of a rider and includes a pair of oppositely disposed sidewalls 104. A generally U-shaped heel loop 112 is attached to the base plate 102 with attachment hardware 103 extending through apertures 105 in the sidewalls 104 and apertures 113 in the heel loop 112. In the preferred embodiment, the apertures 113 in the heel loop 112 are elongate, such that the horizontal position of the heel loop 112 with respect to the base plate 102 may be selectively adjusted. The heel loop 112 includes oppositely-disposed leg portion 114 and a curved intermediate portion 116.
A toe strap 108 (shown in phantom in FIG. 1) is pivotally attached near a front end of the sidewalls 104 with attachment hardware 103 positioned to overlie a toe portion of the snowboard boot. An instep strap 110 is pivotally attached to the heel loop 112 and positioned to overlie an instep portion of the snowboard boot. The toe strap 108 and instep strap 110 are held in a tightened adjustment about the snowboard boot with clasp mechanisms 109 and 111, respectively, which may be ratchet-type, quick-release clasp mechanisms. The straps 108, 110 are preferably padded for the rider's comfort.
A highback 120 is pivotably attached to the heel loop 112 with attachment hardware 130 and 132 described in more detail below. The highback 120 is curved generally about an upright axis, i.e., contoured, to approximately conform to the back of the rider's boot 92 (see FIG. 3). The highback 120 includes oppositely-disposed lower wing portions 122 and a heel portion 124 there between. The heel portion 124 extends generally behind the ankle of the rider. In the preferred embodiment, a blocking member 140 (FIGS. 3 and 4) is adjustably attached to the back of the highback 120, generally constrained to move in an integral channel 128 formed on the back of the highback 120. A quick-release locking lever 142 on the blocking member 140 is movable between a release position and a locked position (shown in locked position). The locking lever 142 is pivoted outwardly, away from the highback 120, to the release position to slidably move the blocking member 140 to a desired position, then returned to the locked position to lock the blocking member 140 at the desired position. The blocking member 140 includes a toothed inner surface 149 that engages corresponding teeth 129 on the back of the highback 120.
It will be appreciated from FIGS. 3 and 4 that the blocking member 140 is positioned to abut an upper edge of the heel loop 112, thereby limiting the backward pivoting motion (or maximum forward lean) of the highback 120. The rider may therefore set the maximum forward lean by positioning and locking the blocking member 140 to a desired position. As noted above, the maximum forward lean is important to the feel and control of the snowboard and a rider's optimal setting is typically dependant on a variety of factors, including the type of snowboarding to be undertaken, the slope conditions, and the like.
Refer now in particular to FIG. 4, which shows a fragmentary cross-sectional view of a portion of the binding 100, including one of the wings 122 of the highback 120. The wings 122 of the highback 120 each has an elongate aperture or curved slot 126 that preferably forms a circular arc centered on a point P. As shown in FIG. 3, the point P approximately intersects the rotational axis of dorsiflexion/plantar flexion of the ankle of the rider. In the preferred embodiment, a similarly curved, inwardly-facing depression or channel 128 surrounds each curved slot 126, the channel 128 having a plurality of transverse teeth 129. An arcuate nut plate 130 having a corresponding set of transverse teeth 139 (shown in FIG. 2) is shaped to fit in the channel 128. The nut plate 130 includes an internally threaded nut or post 131 that is sized to extend through the curved slot 126. As seen most clearly in FIGS. 2 and 3, connecting hardware—such as a bolt 132 and locking member 133—extends through the apertures 115 on either side of the heel loop 112, through the curved slots 126 in the highback 120, and threadably engages the corresponding nut plate 130 to pivotably attach the highback 120 to the heel loop 112.
Refer now also to FIG. 3, which shows a side view of the binding 100 with the toe strap 108 and instep strap 110 removed for clarity, and FIG. 4. The highback 120 may be pivoted in its attachment to the heel loop 112 by rotating the highback 120 such that the nut plate post 131 slidably shifts (relative to highback 120) along the curved slots 126 in the highback wings 122, as indicated in FIG. 4 by arrow 90. The highback 120 is therefore pivotable about a transverse virtual axis through point P that approximately corresponds to the axis of the rider's dorsiflexion ankle joint. As used herein, a virtual axis means an axis that is disposed away from, e.g., not directly through, the highback 120 or the base plate 102. Because the virtual axis is at or near the natural pivoting axis (in dorsiflexion/plantar flexion) of the rider's ankle, the highback 120 can be readily positioned to different maximum forward lean positions with the binding 100 geometry adhering substantially to the natural geometry of the rider's foot and ankle. A person of skill in the art will recognize from the teachings herein that pivoting the highback 120 about the substantially same axis as the natural axis of the rider's ankle will enable the highback 120 to more closely accommodate the rider through the entire range of angular positions available to the highback 120.
To further facilitate the desired pivoting of the highback 120 about the virtual axis through point P, the intermediate portion 116 of the heel loop 112 is curved to approximately conform to the bottom heel portion 124 of the highback 120. (The heel loop intermediate portion 116, of course, is also curved generally about an upright axis to conform generally to the highback 120, i.e., extending from the lateral to the medial side of the boot 92). The highback 120 heel portion 124 is similarly curved about a horizontal axis to approximately nest with the heel loop intermediate portion 116. The conforming curvature in the heel loop intermediate portion 116 and the highback heel portion 124 prevents interference between these components over the range of adjustment for the highback 120 and allows the heel loop 112 to provide positioning guidance and structural support to the highback 120.
In a currently preferred embodiment of the binding 100, the base plate 102 and the highback 120 are formed primarily of a substantially rigid and lightweight polymeric material, and the heel loop 112, which must withstand substantial forces exerted by the rider and the terrain, is made from stainless steel. It will be appreciated, however, that other material choices may be made with the standard application of engineering judgment and these material choices are not intended to limit the scope of the present invention. It is contemplated, for example, that other metals or composite materials may alternatively be utilized.
While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.