Abstract:
A boot binding for a snowshoe, suspended within the snowshoe for flexibility of the boot relative to the snowshoe in the pitch direction, has a binding footbed that is flexible and allows bending of the boot in the pitch directed, as steps are taken by the user.

Description:
BACKGROUND OF THE INVENTION 
     This invention concerns snowshoes of the type having a boot binding secured to the snowshoe, either permanently or by attachment. Specifically the invention concerns a snowshoe binding with a system of straps easily tightened by the wearer, including a heel strap connected to an arch area strap such that tightening the arch strap draws the heel strap tight. 
     Snowshoe bindings, and bindings for cleats or other terrain-engaging footgear, are shown in Atlas Snowshoe Co. U.S. Pat. Nos. 5,440,827, 5,918,387, 6,374,518, 6,401,310, 6,526,629, 6,694,645 and 6,694,646. U.S. Pat. No. 5,687,491 disclosed a contoured footbed in a boot binding (the term “boot” as used herein refers to a boot or a shoe). U.S. Pat. No. 6,694,646 disclosed a snowshoe harness with buckles and straps configured such that a single pull can tighten the harness down to the boot, and including toe area and arch area straps whose tails were connected together as a loop, such that the user need only pull on the loop. As shown in nearly all the above listed patents, a heel strap is provided to secure the user&#39;s boot in the binding, to prevent against pulling back of the boot from the tightened toe and arch areas on the binding during use of the snowshoe or cleat device. 
     U.S. Pat. No. 6,694,646 described a snowshoe binding with a versatile, adjustable, convenient and efficiently used means for tightening toe and arch straps. That binding system works well, but it would be desirable to allow the user to tighten the heel strap at the same time as tightening one or both of the arch and toe straps, thus to avoid the need for the twisting and bending motion involved in drawing tight a heel strap. 
     Atlas Snowshoe Co. U.S. Pat. No. 6,694,645 shows a lace binding for a snowshoe wherein the lace tightens harness webbing over the top of the boot and also pulls tight a heel strap. 
     SUMMARY OF THE INVENTION 
     Pursuant to this invention, a binding for a snowshoe or other terrain-engaging sport wear includes a heel strap that is connected to at least an arch area strap, so that a pull to tighten the arch area strap draws the heel strap tight. In a preferred embodiment the arch area and toe straps of the binding have tail ends connected together to form a single loop that tightens both, as in the &#39;646 patent discussed above, and with the arch area strap continuing through guides in the binding harness to serve as a heel strap. Thus, a single pull by the user on the loop tightens both over-the-boot straps and also the heel strap. The harness shell to which the straps are attached can be formed similarly to that of the &#39;646 patent, but with one or more strap guide slots for continuing the arch area strap to extend into the heel strap, rather than having the arch strap fixed to the binding shell or webbing at that location. In addition, the binding shell preferably has a strap guide extension extending back toward the heel, to help hold the heel strap in position, and a further flexible but relatively stiff strap guide is included at the opposite side of the binding, secured to or enclosing the heel strap at such opposite side so as to hold the heel strap in a generally horizontal position and ready for the user to step a boot into the binding and to engage the strap system without having to manually position the heel strap. 
     The binding can additionally include a flexible footbed, with flexibility for bending at the metatarsal phalangeal joint of the foot. The footbed in this embodiment is only rigid at the toe area, forward of the metatarsal phalangeal joint location (where it is secured to a toe cleat), and the over-the-boot strap in the arch region is connected to the back portion of a flexibly compliant footbed element. The footbed can also include a sliding width adjustment at the arch. 
     In one particular embodiment the snowshoe binding of the invention comprises a footbed for engagement against the bottom of a user&#39;s shoe or boot and adapted for securing to a snowshoe, with a boot binding extending up from the footbed, the binding at one side having a shaped, flexible harness shell adapted to engage the shoe or boot at the side and at least partially over the top of the shoe or boot. At an opposite side of the binding is another flexible harness element. 
     A first flexible strap is fixed to the one side at the footbed, extending to the other side and looping through the flexible harness element, then returning back toward the harness shell and being engaged in and passing through an adjustable locking buckle connected to the flexible harness shell. 
     A second flexible strap is connected at said other side to the footbed and crosses generally to a position above the arch area to a second adjustable locking buckle connected to the flexible harness shell. 
     A heel strap extends back from the boot binding in a generally horizontal loop, fixed to the boot binding at one side and held in place by a guide or stiffener. The heel strap at the opposite side is secured to (and can be continuous with) the second flexible strap, and can be held by a slip-through slide guide on the binding, whereby tightening of the second flexible strap generally over the arch area is effective simultaneously to tighten the heel strap. 
     Preferably the two straps, for the toe area and arch area, are connected at their tail ends to form a grippable handle extending generally between the two buckles, capable of being pulled by the user to draw both straps with one pull, such that the pulling of the strap handle effects tightening of the toe area, the arch area and the heel. In a preferred form, all straps comprise one continuous strap. 
     In one specific embodiment of the invention the width of the snowshoe binding and strap engagement against the boot in the arch area are adjustable, preferably via a simple lateral slide mechanism, to accommodate boots of different widths. The arch region strap and an adjustment buckle for the strap are so arranged that the pulling of the arch region strap to tighten the binding will tend to pull the slide adjustment device into contact with the sides of the boot as the strap is tightened. 
     It is thus among the objects of the invention to improve on boot bindings for snowshoes or other terrain-engaging footgear, such as snow cleats or ice cleats, by providing for greater convenience and ease of use in tightening the binding on the user&#39;s boot. These and other objects, advantages and features of the invention will be apparent from the following description of preferred embodiments, considered along with the accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a snowshoe binding of the invention, shown detached from a snowshoe. 
         FIG. 2  is a detail view in side elevation showing a portion of the same side of the snowshoe binding. 
         FIG. 3  is a detail view in cross section showing a laterally slidable adjustment at or near the arch area of the binding, as can be included in an embodiment of the invention. 
         FIG. 4  is a detail view in side elevation showing a modification of what is shown in  FIG. 2 . 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the drawings,  FIG. 1  shows a binding  10  for retaining a user&#39;s shoe or boot (“boot” herein), either in a snowshoe to which the binding is attached, or simply as a cleat for walking on icy terrain or densely packed snow. The binding  10  as shown in  FIG. 1  is a preferred and specific embodiment of the invention, wherein a single pull of a loop  12  will tighten straps  14 ,  14   a  (generally in the toe area of the boot) and  16  (generally in the arch area of the boot), as well as a heel strap  18 , with a single pull. The strap arrangement is generally similar to that shown in the &#39;646 patent referenced above, although this can vary if desired. The most important feature of the invention is that the heel strap  18  is connected to the arch area strap  16 , preferably comprising a single continuous strap for both the heel and the arch area. The heel strap is supported in position, even when not tightened against a user&#39;s boot, by a strap support and stiffening device  20 , which may be fixed to the heel strap  18  as a stiffener (still allowing the needed flexibility to bend around the heel) or which can be a tube element as shown, with the strap  18  inside. The strap support/stiffener  20  is connected onto a harness shell or webbing element  22  to extend back therefrom, as shown in the drawing. This holds the strap  18  in a generally horizontal loop as shown, the strap  18  passing through one or more strap guide slots  24  in an opposite side of the boot binding or harness shell  26 . The harness shell or webbing element  26  preferably is integral with the component  22  at the one side, as can be seen in the drawing, the unitary flexible element  22 / 26  being fixed down to a footbed  28  and metal cleat  30 . The preferably plastic harness shell element  22 / 26  can be a layer between the cleat  30  and the footbed  28  as shown, with rivets or bolts securing this three-layer sandwich construction together. 
     The stiffener or guide sleeve  20  is flexible so as to bend around the back end of the boot and to conform to the boot as needed, but is relatively stiff in the other direction of bending, such that it reliably holds the strap in the generally horizontal loop position shown, and the user need only step the boot into the binding, once the straps are sufficiently loosened, then pull the strap handle loop  12  to tighten the heel strap along with the over-the-boot straps. 
     In the form shown, the strap or strap portion  16  is further guided by a slotted guide piece  32  secured to the harness element  26 , and this guide  32  along with the one or more slot guides  24  serve to transition the strap in its sliding movement from the arch area portion  16  to the heel strap  18 , allowing for smooth tightening and loosening of the heel strap when the strap  16  is tensioned. 
     In U.S. Pat. No. 6,694,646, which is fully incorporated herein by reference, the looped strap handle arrangement was similar, except that the arch area strap, in the position of the strap  16 , was fixed to a portion of the boot binding or harness shell, rather than continuing into the heel strap. 
     It should be understood that the snowshoe binding  10  of the invention can be made, if desired, without the loop  12  connecting the tail ends of the forward and rear straps  14  and  16 . Although the single-pull loop form is preferred, a rear strap or arch area strap  16 , independent of the forward strap  14 , and which connects with or is continuous with a heel strap  18  such that tightening of the arch area strap also tightens with the heel strap, is within the principles of the invention. 
     As can be seen from  FIGS. 1 and 2 , other guide slots or loops  34  and  36  are configured so as to allow smooth travel of the strap  16  upon tightening or loosening. The strap guide  32  is seen in better detail in  FIG. 2 , showing its slotted opening  38  for the strap  16 , and also indicating a second, parallel slot  40  for different positioning of the strap if needed for better adjustment or slidability. 
       FIG. 1  shows that forward strap  14 ,  14   a  passes through slots  42  at or near the front end of the harness shell element  22 , to guide and hold in position the strap  14  near its forward end, and that the strap  14  passes around a flexible harness element  26   a , through an opening provided by the flexible harness element, in the same manner as disclosed in the &#39;646 patent. These attachments of the forward strap portion provide for versatility in fitting to a user&#39;s boot, with the ability of the harness shell to open or close around boots of different sizes and the ability of the strap  14 / 14   a  to be positioned more forward or more rearward along the flexible harness element  26   a  as needed for the particular boot configuration. 
     Strap buckles  44  may comprise cam lock buckles as disclosed in the &#39;646 patent, which can be generally of the type shown in U.S. Pat. No. 6,526,629. Alternatively, these buckles can comprise other types of slip-through adjustable locking buckle, well known in the art. 
     As mentioned above, the snowshoe binding  10  of the invention can include a flexible footbed, if desired, as disclosed in co-pending application Ser. No. 11/335,848. Such a flexible footbed, which can be formed of plastic, is secured to the metal cleat member  30  only at the forward end of the footbed, allowing the user to bend the boot and foot at the metatarsal phalangeal joint, thus making use of the snowshoe or terrain-engaging device much more comfortable. In that case the rear portion of the footbed “floats”, relative to the metal cleat  30 , and the binding elements  22 ,  26  and the straps move along with the rear portion of the footbed. 
     In addition, as also described in the referenced co-pending application, the arch area of the footbed can include a slidable width adjustment if desired. With such a width adjustment, the two opposed portions  22  and  26  of the harness shell are actually separate pieces, slidable toward and away from one another at the rear or arch region via a simple sliding element. Tightening of the rear strap  16  and the heel strap  18  has the effect of sliding the width adjustment device together, to engage the boot at the desired width. A detail of such a slide adjustment is shown in the transverse sectional view of  FIG. 3 . In  FIG. 3  a sliding element  48 , which is secured to or part of the harness element  22 , is seen retained by a pair of fasteners  50 , which extend through a slot  52  of the slider  48  and are engaged through the flexible footbed element  28   a  at the top and to a retaining strip  54  at the bottom. This allows the sliding piece  48  to slide laterally for width adjustment without much friction. The user&#39;s boot is inserted into the binding with the sliding element pulled out to maximum width (to the left in  FIG. 3 ). When the straps are tightened using the loop pull  12  ( FIG. 1 ), or otherwise using the arch area strap  16 , this pulls the sliding element  48  inward, along with the harness shell element  22 , so that the harness element  22  engages snugly against the side of the boot. 
     It should be understood that the harness shell  22  and harness element  26  shown in the drawings and discussed above need not be configured as shown. Some type of transitioning strap-passing device is needed for transitioning the strap between the arch area strap  16  and the heel strap  18 , and this element should be attached to the footbed, but the remainder of the harness element  26  can be configured otherwise. For example, the front strap  14 ,  14   a  could merely pass through a slide loop at the side of the footbed rather than through the arching loop portion  26   a  as shown. Further, the strap portion  14   a  could simply be fixed to the footbed at the near side of the binding as seen in  FIG. 1 . The harness shell  22  could be a much smaller device, sufficient to suspend the heel strap with a stiffening element, but the straps  14   a ,  16  could be relied on to engage over the boot, without such an extensive harness shell. The buckles  44  could merely be secured to fixed straps fixed down to the one side of the footbed (the far side as seen in  FIG. 1 ). 
       FIG. 4  shows an alternative to  FIGS. 1 and 2  in the strap slide arrangement. Here, the arch area strap portion  16  transitions to the heel strap portion  18  through a preferably arch-shaped slot  60  formed toward the rear in the binding element  26   a , then through a slide loop  62  integrally formed in the same element  26   a , at the rear of the element. This avoids the need for the strap guide  32  attached to the side of the binding element as described above. The slot  60  and the formed slide loop  62  are shaped in a way to guide the strap or along a direct path and with as little friction as possible. The binding element or harness shell  26   a  may be formed of a rubbery plastic or thermoplastic such as SEBS or other suitable material. If desired a grommet or coating of a lower-friction, stiffer plastic could line the slot  60  for reducing friction further. The slot  60  is elongated and configured preferably as an arch, to accommodate the angulation of the strap  16  as it passes through the slot, requiring a wider space and to allow for differences in position of the strap  16  due to different positions of the harness shell for different shoe sizes. 
     A heel strap stiffener  20   a  is also visible in  FIG. 4 , similar to the heel strap stiffener  20  but in this case simply comprising a rear extension of the flexible harness shell  22   a , on the opposite side of the binding from the slot  60  and the guide  62 . The strap stiffener  20   a  is a formed extension of the shell, and end of the strap portion  18  is simply secured to this harness shell extension  20   a  near its end, as by a rivet. The approximate connection is shown, as an example, at  64  in dashed lines, being on the opposite side of the binding from the strap portion  18  visible in  FIG. 4 . As in the above described heel strap stiffener  20 , the device  20   a  holds the heel strap in position for entry of a boot into the binding so as to avoid the need for manual positioning of the heel strap by the user. 
     The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.