Abstract:
An apparatus for tensioning the cable or bail of a ski-touring binding, a tensioning lever for such apparatus, and a replacement component for the lever are provided. The apparatus provides different tension for walking and for skiing. The lever includes a handle and a pivot for rotational engagement of the lever on the cable or bail. The pivot is located between the handle and a plurality of boot heel holders. The holders are configured such that at least one holder will contact the ski boot heel at a different distance relative to the pivot than another of the holders. The replacement component is removably fixed to the lever and is configured to provide a heel holder surface and to retain a bail or cable in rotational engagement with the lever.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to U.S. provisional patent application Ser. No. 60/538,223 filed Jan. 23, 2004, the content of which is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates to ski bindings adapted for use with a flexible ski boot and which allow a heel portion of the boot to lift free of the upper surface of the ski while in use.  
       BACKGROUND OF THE INVENTION  
       [0003]     Cross-country and telemark ski bindings, referred to herein as “touring bindings” are designed for use with a ski boot which is sufficiently flexible near the ball of the user&#39;s foot to permit the boot to flex upwards and forwards while the toe of the boot remains fixed on the surface of a ski. This permits the user to perform a relatively normal walking motion while travelling uphill or on flat ground and to lift the heel of the boot from the ski in order to perform a telemark-style turning maneuver. Traditionally, such boot flexibility was provided by the materials from which the ski boot was constructed. For example, a ski boot with a leather upper can be quite flexible. Also, boot soles comprising a combination of leather and rubber are also quite capable of flexing near the ball of the foot. More recently, the uppers and soles of telemark ski boots have been constructed from synthetic plastic materials which are less flexible than leather or rubber. To compensate for the use of synthetic materials, modern telemark boots will typically include a compressible bellows in the upper portion of the boot near the ball of the foot which allows flexing of the boot.  
         [0004]     A touring binding will comprise a toe piece adapted to hold the toe of the boot at an appropriate location on the upper surface of the ski while leaving the heel portion of the boot free to rise above the ski surface. Some designs of cross-country bindings provide means such as a clamp or pins for fixably retaining the toe of the boot within the toe piece. However, other designs which lack means for such fixing the toe of a boot in the toe piece make use of a cable, bail, or cable and bail combination which extends around the heel of the boot to provide constant tension whereby the boot is urged forward into the toe piece and is retained. Such cable and/or bail assemblies have also been employed to reduce lateral movement of the heel of the boot and to provide means for biasing the heel of the boot towards the ski surface in order to obtain better control of the ski, particularly during downhill skiing.  
         [0005]     Tension is typically provided in the aforementioned cable and/or bail assemblies by one or more springs. For example, the binding may comprise a spring-loaded lever mounted to the ski forward of the toe piece to which a cable assembly is attached. Movement of the lever will shorten the rearward extent of the cable relative to the toe piece thereby tensioning the cable about the heel of the boot. In other versions, the lever may be present elsewhere, for example on or near the heel of the boot. Springs may also be situated elsewhere in the assembly, such as at intermediate coaxial positions in the cable/bail assembly alongside or underneath the boot. Springs employed in such bindings include those which operate while under tension (i.e. the spring is stretched while in use) as well as spring assemblies in which a compressed spring provides a directed force which tensions the cable or bail assembly. Regardless of the nature of the spring(s) or their location in the ski binding, employment of synthetic plastic materials in telemark boots has permitted the use of springs which provide for greater tension without buckling or significantly compressing the boot than springs traditionally used with leather boots. This gives the advantage of greater stability during turning and in other downhill maneuvers.  
         [0006]     Upwards and forward flexing of a boot in a touring binding results in the sole of the boot adjacent the ball of the foot lifting from the surface of the ski. Since the cable and/or bail assembly is fixed or hinged at selected points on the toe piece, such upward movement of the boot generally results in increased tension being applied through the cable/bail assembly to the heel of the boot while the boot rises. While this greater tension serves to bias the heel of the boot downwards and thereby provides some stability for certain maneuvers, such an increase in tension must be overcome by the user while walking and travelling uphill. When stronger springs are employed, the user will have to perform greater work in lifting the heel of the boot during walking and uphill travelling motions. Even in bindings designed to minimize the difference in tension while the boot flexes, use of higher tension levels to provide downhill stability will increase the bias of the boot towards the ski surface at all flex positions. This can be disadvantageous while climbing uphill using climbing skins since the bias effect tends to lift the ski from the snow surface as the boot flexes forward. With climbing skins, the user may wish to maximize contact with the snow to reduce backwards slippage.  
         [0007]     Traditionally, the heel counter of a ski boot extends rearwards some distance and is separated from the boot upper by a welt. This provides an upward facing ledge extending around the circumference of the upper portion of the heel counter and is often used to engage a ski binding element. This feature is often retained in modem plastic ski boots and is included in the I.S.O. standards for ski boots (e.g. ISO 9523:1990). The welt is often retained as a feature on plastic boots employed for cross-country and telemark purposes, but not always. Nevertheless, all cross-country and telemark boots designed for use with cable/bail assemblies will at least have a lateral groove formed around the circumference of the heel counter of the boot below the level at which the welt typically appears. This groove is typically used for placement and engagement of a cable or bail of a touring binding or for placement of a tensioning lever.  
         [0008]     Tensioning levers have been employed for many years to retain a cable and/or bail on the heel of a ski and boot. Such cable and/or bail assemblies with tensioning levers have been found in alpine-style bindings in which the heel is continually retained against the surface of the ski; in alpine-touring bindings in which a rigid boot is retained against a plate or bar hinged at the toe of the boot to the ski surface thereby permitting the rigid boot to rise above the ski surface; and, in touring bindings used with flexible boots. Such tensioning levers have also been employed to retain cable or bail assemblies on the heel of boots in other applications such as the case with “step-in” style crampons which are intended to be attached to the full length of the sole of a mountaineering boot without any tendency for separation of the crampon from the boot sole during use.  
         [0009]     Tensioning levers operate on the “over-center” principle. The lever will typically comprise a handle portion opposite a portion shaped to engage or clamp a ledge, groove, or other feature on the heel of the boot (a “boot holder”). The lever is rotationally engaged on the cable or bail at a pivot location situated between the handle and the boot holder. The lever is arranged so that when the boot holder is placed on a boot feature and the lever is rotated by means of the handle (typically upwards), the boot feature will come under clamping engagement while the pivot is displaced from a series of positions which place zero, then high, then moderate tension on the cable. The lever retains the cable on the heel of the boot because in order to reverse rotation of the lever thereby releasing it from the boot, the tension on the cable must pass from the moderate to the high tension positions as the lever again passes “over-center”, the boot is released. An example of a modem touring binding which employs a heel tensioning lever is the TARGA™ binding produced by G3 Genuine Guide Gear of North Vancouver, British Columbia, Canada. Another example of such a touring binding is the HAMMERHEAD™ binding produced by Rainey Designs of Wilson, Wyo. U.S.A.  
         [0010]     The tensioning lever of the HAMMERHEAD™ binding referenced above is designed to assist the user in locating the lever in the lateral groove of a boot heel. This lever, which has been referred to as having a “beaver tail” design consists of a standard lever handle, boot holder means, and a pivot therebetween. Adjacent the boot holder and extending away from the pivot point opposite the handle is a plate provided as a separate element which is removably attached to the lever by means of a fastener. The binding bail assembly is adjusted so that when the user places a boot into the binding with the heel lever rotated backwards and flat to the ski, the heel of the boot will clear the boot holder portion yet contact the plate. The distance between the plate and the heel holder portion is such that once the boot contacts the plate and the user rotates the lever upwards by pulling on the handle, the heel holder will automatically locate and engage the lateral groove of a standard telemark boot heel. In order for the plate to be effective, it must extend away from the pivot the same distance as the heel holder. A different apparatus with a similar boot locating function is found in the V-CAM™ of Voile Equipment (USA) where the heel tensioning element comprises a semi-circular rocker with a boot holder portion and a plate extending from the pivot as far as the boot holder. Stepping on the plate causes rotation of the rocker which automatically engages the heel holder with the lateral groove of a boot heel.  
         [0011]     In the past, users of touring bindings that employ a tensioning lever may have compensated for resistance to boot flexing caused by binding tension during walking and uphill maneuvers by rotating the lever past the “over-center” point, thereby disengaging the boot holder from the boot heel. If the overall length of the cable or bail assembly permitted, a surface on the lever other than that which is adapted to clamp the boot might be loosely engaged with a feature on the boot heel keeping the cable/bail from coming to rest on the ski surface and to some extent, preventing the boot from moving rearwardly. In bindings where the cable or bail assembly is the only means for retaining the boot within the binding, such loose engagement would not prevent the boot from becoming completely detached from the binding when significant forces were exerted by the user (such as when kicking or lifting the ski).  
       SUMMARY OF THE INVENTION  
       [0012]     The inventors herein have realized that a tensioning lever for a ski-touring binding may be significantly improved by providing at least two boot holders, each being sized to contact the heel of the boot at different distances relative to the cable/bail pivot on the lever. A boot holder situated at a greater distance from the pivot will displace the pivot a greater distance when that boot holder is engaged on the heel of the boot as compared to a second boot holder on the lever which displaces the lever to a lesser degree. This improvement has been unappreciated until now despite many years of use of heel tensioning levers on touring bindings. With this invention, the user may now employ one of a plurality of heel holders on the tensioning lever to engage the boot with a tension sufficient to secure the boot in the binding for walking and uphill travel yet subjecting the boot to less tensional force than is preferred for downhill travel and turning maneuvers. The greater tension preferred for downhill travel and turning maneuvers is provided by selectively engaging a second boot heel holder on the lever which extends further from the pivot thereby displacing the pivot point of the lever a greater distance from the boot heel when engaged causing greater tension to be exerted on the boot. By simply moving the lever from one position to another, the user may switch from a walking mode which requires less energy to flex the boot to a “downhill” mode in which the boot is held under greater tension.  
         [0013]     This invention provides an apparatus for tensioning a cable or bail of a ski-touring binding on a heel of a ski boot, the apparatus comprising a lever including a handle, first and second heel holders, and a pivot for rotational engagement of the lever to said cable or bail, wherein the pivot is located between the handle and said first and second holders, said holders being configured such that the first holder will contact said ski boot heel at a different distance relative to the pivot than the second holder.  
         [0014]     This invention also provides a heel tensioning lever for a ski-touring binding, the lever comprising: means for actuating the lever and for contacting a rear portion of a ski boot; rotational means for engagement with a cable or bail of the binding, the rotational means having a rotational center; and a plurality of means for clamping engagement with a heel of a boot sole, each of said clamping means having a surface for contacting cable engagement means on the heel, wherein each contacting surface has a point at a minimum distance to the rotational center with the minimum distance for at least one of said contacting surfaces being less than the minimum distance for another of the contacting surfaces and wherein the clamping means having a lessor minimum distance for its contacting surface will provide lesser tensioning of the cable or bail then clamping means having a greater minimum distance for its contacting surface.  
         [0015]     The apparatus or heel tensioning lever of this invention may further comprise a cable or bail of a ski-touring binding as well as a toe piece of a ski-touring binding.  
         [0016]     The apparatus or heel tensioning lever of this invention may comprise first and second clamping means or boot heel holders which are spaced apart, each comprising a surface for contacting cable engagement feature or means of a ski boot heel. Such a cable engagement feature or means may be the ledge of a boot heel welt or the lateral groove of a boot heel. Preferably, the clamping means or boot heel holders will be shaped to fit or conform to such a cable engagement feature or means. Preferably, the shape will include a concave surface for contacting the cable engagement feature or means. Preferably, the contact surface will conform to the curvature of a ski boot heel. However, the holder or clamping means may include a plurality of spaced apart surfaces for contacting the boot heel thereby improving contact with the curvature of the boot heel.  
         [0017]     The boot heel holders or clamping means are typically spaced apart, preferably at a distance to readily permit one such holder or means to engage the lateral groove of a ski boot heel while permitting another of the holder or means to engage the heel welt upon rotation of the lever about the pivot.  
         [0018]     In order to provide for contact of individual boot heel holders or clamping means at different distances relative to the pivot, each holder or means will typically extend a different distance from the rotational center of the pivot. Given that each boot heel holder or clamping means may be shaped to improve engagement with a boot heel and will be preferably concave or comprising spaced apart surfaces, a convenient measure of the distance by which an individual boot heel holder or clamping means extends away from the pivot is to determine the minimum distance between the rotational center of the pivot and the surface on the boot heel holder or clamping means which contacts the boot heel. Thus, the surface will contain a notional point which is at the minimum distance to the pivot center and is closest to the pivot center. Preferably, the minimum distance for one boot heel holder will be about 0.95 to about 0.50 of the equivalent minimum distance for another boot heel holder or clamping means. Preferably, the aforementioned ratio will be about 0.90 to about 0.50, even more preferably about 0.85 to about 0.50, and even more preferably about 0.85 to about 0.60, although the specific ratio in any particular embodiment of this invention may fall anywhere within the aforementioned ranges.  
         [0019]     An apparatus or lever of this invention will comprise a handle for actuating the lever, which handle will typically be sized and shaped for ease of manipulation by the user. The handle rests against the back of the boot when engaged on the boot and therefore may be shaped at such a resting surface to conform to the shape of the most rearward portion of a typical boot body. The lever will be “over-center” when either of a first and second heel holder or clamping means configured to contact the boot heel at different distances are engaged on the heel of the boot. This “over-center” aspect is provided for in part by selecting an appropriate position for the pivot in the lever relative to the boot contact surfaces of each boot holder or clamping means. However, the “over-center” aspect may be most ensured regardless of the particular boot with which the binding is used by positioning the boot contact surfaces of the heel holders or clamping means relative to the pivot center so that notional points on the contact surfaces of first and second boot holders or clamping means located on each surface at the minimum distance to the rotational center, in combination with the rotational center will represent a notional acute or right angled triangle. Thus, an angle represented by intersection of a first notional line representing the minimum distance for at least one boot holder or clamping means and a second notional line joining the points of minimal distance on the contact surfaces of each of the holders or clamping means will be 90° or less. In some embodiments, the angle may be about 85° or less or about 80° or less. In many embodiments, the angle will be at least 60°.  
         [0020]     Heel tensioning levers of this invention may be of one piece or multi-piece construct. Some embodiments of an apparatus or heel tensioning lever of this invention may advantageously be constructed such that the handle and at least one heel holder or clamping means form an integral component while another heel holder or clamping means is provided on a separate, removable component that may be fixably attached to the integral component. Preferably in such an embodiment, the pivot will be located between the integral component and the removable component so that fastening of the removable component to the integral component may serve to retain a cable or bail at the pivot and disengagement of the removable component from the integral component will facilitate removal of the cable or bail from the pivot. Thus, this invention also provides a replacement component for a heel tensioning lever for a ski-touring binding, the lever comprising a handle, a plurality of boot heel holders, and a pivot for rotational engagement of the lever with a cable or bail of said binding, wherein at least one of the heel holders and the handle form an integral component, wherein the replacement component is configured to be removably fixed to said integral component to provide another of said heel holders on the lever, and to retain the bail or cable of the binding in rotational engagement with the tensioning lever at the pivot.  
         [0021]     The pivot of an apparatus or heel tensioning lever of this invention may be any means for providing rotational movement of the lever relative to a cable or bail. Thus, the rotational means or pivot may be a through hole in the lever for receiving a cable or bail or may comprise an element such as a pin, rotational joint, or other such device adapted to be attached to a cable or bail or the end of a cable or bail so as to permit rotational movement of the lever relative to the cable or bail. In one embodiment of a removable component of this invention, the removable component comprises a curved wall, which when placed adjacent a similar curved wall in the integral component when the two components are joined, effectively forms a cylindrical or partially cylindrical through hole in the lever in which a cable or bail may be retained. Separation of the parts opens the through hole thereby permitting release of the cable or bail.  
         [0022]     An apparatus or heel tensioning lever of this invention may be employed with any cable, bail, or cable/bail assembly of a touring binding or any touring binding comprising such a cable, bail, or cable/bail assembly which further comprises a ski binding toe piece and springs or other tensioning means for providing a constant tensioning force on the cable or bail. A cable is typically a longitudinal flexible element usually of cylindrical cross-section. A bail is typically a longitudinal element which is rigid or more rigid than a flexible cable, typically of a cylindrical cross-section. Many bindings employ a combination of a cable and bail. For example, a bail portion of the assembly may be employed at the heel of the boot and is engaged with a heel tensioning lever. Forward ends of the bail are joined to flexible cable elements which extend forwards to fixation points on the toe piece of the binding. However, it is possible for the binding to make use of only a bail assembly which is more rigid than a cable and will typically require the use of hinge elements for joining the bail at the toe piece. Springs or other resilient means for providing constant tension in a touring binding which makes use of this invention may be any such means employed for such purposes. One or more springs may be present in a single binding. The springs may operate under tension or compression and may be exposed or contained within cartridges as are typically used on touring bindings today such as the aforementioned TARGA™ models. The springs or other elastic means may be located within a cable/bail assembly, between a cable/bail assembly and a toe piece, beside the boot, underneath the boot or forward of cable/bail fixation or hinge points on the toe piece. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]      FIG. 1  is a side view of a SCARPA™ touring ski boot containing features typical of plastic boots for telemark skiing.  
         [0024]      FIG. 2  is a side view showing the boot of  FIG. 1  in a TARGA™ touring binding (prior art). The binding is shown relative to the upper surface of a ski to which the binding components are fixed. The boot is shown in an elevated position typical of what is achieved during walking, climbing, and telemark turn maneuvers.  
         [0025]      FIG. 3  is an isometric view from the rear of the prior art heel tensioning lever shown in  FIG. 2 .  
         [0026]      FIG. 4  is an isometric view of a TARGA™ touring binding (ski not shown) modified in accordance with this invention to include a heel tensioning lever of this invention.  
         [0027]      FIGS. 5A and 5B  are isometric views of the heel tensioning lever illustrated in  FIG. 4  with such views angled from the rear and the front of the heel tensioning lever, respectively.  
         [0028]      FIG. 6  is a side view of the heel tensioning lever illustrated in  FIG. 4 ,  FIG. 5A , and  FIG. 5B .  
         [0029]      FIG. 7  is an exploded isometric view of the components of the heel tensioning lever illustrated in  FIG. 4 - FIG. 6 .  
         [0030]      FIG. 8  is an isometric view of the heel lever illustrated in  FIG. 4 - FIG. 7  joined to a bail of a TARGA™ touring binding.  
         [0031]      FIG. 9A - FIG. 9F  are partial side views of the heel portion of a typical touring ski boot showing the heel counter region and a portion of the boot upper adjacent the heel. Also shown are side views of the heel tensioning lever illustrated in  FIG. 4 - FIG. 6  joined with a binding bail (partially shown).  FIG. 9A -FIG. F illustrate a sequence of events during which a user may engage and disengage a heel tensioning lever of this invention at the heel of a boot. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]     The invention will now be described more particularly with reference to individual and preferred embodiments as illustrated in the attached drawings.  
         [0033]     A modem touring or telemark ski boot  1  made from synthetic plastic materials is illustrated in  FIG. 1 . In the boot heel region, welt  4  forms a ledge on top of heel counter  3  which faces towards boot upper  2 . The heel counter further comprises lateral groove  5 . Welt  4  and lateral groove  5  are representative of cable engagement means or features typical on ski boots used with touring bindings. The boot has a toe  6 , sole  7 , and compressible bellows  8  which permits forward and upward flexing of the boot near the region  10  of the ball of the foot.  
         [0034]      FIG. 2  illustrates the kind of boot shown in  FIG. 1  placed in a prior art touring binding consisting of toe piece  11  which retains the toe of the boot against ski upper surface  12 . Boot  1  is shown in an elevated position made possible by the design of binding  11  and the flexibility of compressible bellows  9  of boot  1 . A touring binding may also comprise heel plate  13  which is typically a separate component fixed to ski surface  12  on which the heel of the boot will rest when the boot is not in an elevated position. Binding  11  permits upward and forward flexing of boot  1  because only the boot toe  7  (not visible in  FIG. 2 ) is retained by binding  11  by means of bar or plate  14  which extends across the toe of the boot. Boot  1  is retained in binding toe piece  11  by tension directed forward of the boot which tension forces are delivered to the boot through a cable and bail assembly which in the TARGA™ model comprises flexible cable  15 , bail  16 , and heel tensioning lever  17 . Bail  16  has a threaded end  18  adapted for coaxial engagement with compression spring cartridge  19  which is in coaxial engagement with flexible cable  15 . The cable/bail assembly is fixed by cable guide  20  at the toe piece  11 . In this model, flexibility of cable  15  at guide  20  provides for a hinge action at toe piece  11 . Spring cartridge  19  contains an internal mechanism comprising a spring which is compressed when in use and cable  15  or bail  16  is engaged with the compression spring in such a manner as to deliver tension forces to the cable/bail assembly. Although the mechanism of cartridge  19  is not illustrated, a variety of such cartridges are available for use in touring bindings.  
         [0035]      FIG. 3  illustrates the prior art heel tensioning lever  17  shown in  FIG. 2  and used on the TARGA™ binding. Lever  17  comprises handle  21 , pivot  22 , and boot holder  23 . In this embodiment, pivot  22  is a generally cylindrical through hole extending in a direction which will be transverse to the orientation of the lever relative to the boot when in use. To facilitate placement of a bail or cable of a touring binding within the through hole of pivot  22 , lever  17  is further comprised of a removable component  24  which may be fixably attached by means of a suitable fastener placed in opening  25 . A portion of the cylindrical walls of the through hole of pivot  22  is found on removable component  24 . Thus, separation of component  24  from the lever makes it possible to remove a cable or bail retained within the through hole during use. Lever  17  comprises cut-away portions separated by ridges  26 , which reduces the weight of the component while providing sufficient rigidity.  
         [0036]      FIG. 4  illustrates a TARGA™ binding such as is shown in  FIG. 2  without a boot and modified to contain a heel tensioning lever  31  of this invention. Heel tensioning lever  31  is illustrated in combination with an entire touring binding for use on a single ski. Tensioning lever  31  may also be used in combination with any touring binding which includes a cable or bail extending around the heel of a boot.  
         [0037]      FIG. 5A  and  FIG. 5B  illustrate the differences between heel tensioning lever  31  of this invention as compared to the prior art lever  17  shown in  FIG. 3 . Lever  31  comprises handle  21 , pivot  22 , and heel holder  23 . In the lever of this invention, removable component  34  forms part of pivot  22  as was the case for component  24  in  FIG. 3 . Thus, use of removable component  34  continues to facilitate insertion or removal of a cable or bail at pivot  22 . In  FIGS. 5A &amp; 5B , threaded fastener  36  is illustrated.  
         [0038]     The side of lever  31  which is configured to face the rear and heel of the boot when in use is illustrated in  FIG. 5B  and the features shown therein are typical of tensioning levers used to date, including the prior art lever shown in  FIG. 3 . As is shown in  FIG. 5A , heel holder  23  is rounded at its terminus  39 . Terminus  39  is preferably shaped to conform or fit to a cable engagement means on a ski boot such as welt  4  or lateral groove S shown in  FIG. 1  and illustrated in engagement with lateral groove  5  in  FIG. 2 . Facing forwards, the lever has a concave surface  37  configured to generally conform to the rearward curvature of a boot heel counter. This provides greater stability while the lever is in clamping engagement with the heel of a boot. Since surface  37  is concave, only a point on a notional line  38  will be the point on surface  37  which is closest to rotational axis  40  of pivot  22 . The minimum distance between rotational axis  40  and the closest point on notional line  38  represents the minimum distance between the center of pivot  22  and the contact surface defined by reference numbers  37  and  39  which contacts an engagement feature on the heel of a boot.  
         [0039]     Lever  31  illustrated in  FIGS. 5A and 5B  comprises a second heel holder  43  which is provided as an extension. In this embodiment, heel holder  43  includes two, spaced apart members which provide spaced apart boot contact surfaces  44  and  45  which are adapted to contact the curved surface of a boot heel. In an alternate embodiment not illustrated, heel holder  43  may be shaped in a manner similar to heel holder  23  providing a concave boot contact surface, which may also be extended laterally as is the case with holder  23 . In the illustrated embodiment, a minimum distance from rotational axis  40  to boot contact surfaces  44  or  45  of holder  43  may be measured in a straight line from axis  40  to the contact surface  44  or contact surface  45  since both are at the same distance from the pivot center. In the illustrated embodiment, the minimum distance from the rotational axis  40  to the boot contact surface for heel holder  43  provided on component  34  is less than the minimum distance for heel holder  23 . When heel holder  43  is engaged with a feature on the heel of a ski boot, rotational axis  40  will be at a lesser distance from the boot heel than when the lever is engaged on the boot heel using holder  23 . Thus, a lesser amount of tension will exist in the cablel/bail assembly of a binding when holder  43  is engaged as compared to holder  39 .  
         [0040]      FIG. 6  illustrates a side view of a tensioning lever of this invention. In side profile, holder  43  is generally wedge shaped terminating in contact surface  45  which has a curved terminal profile. This shape facilitates engagement with a cable engagement feature on a boot, particularly the lateral groove. This Figure also illustrates determination of minimum distances of holders  23  and  43  relative to the center of pivot  22  although not necessarily drawn to scale in the Figure. The closest point of the concave contact surface of holder  23  is on notional line  38 . The minimum distance for the illustrated embodiment for holder  43  may be measured to contact surface  45  from the center of pivot  22 . Imaginary lines  51 ,  52 , and  53  shown in  FIG. 6  follow these minimum distances and illustrate that points at the minimum distances on the contact surfaces of the two boot holders relative to the center of pivot  22  form an acute triangle in this embodiment with angle θ being less than 90°. Preferably, this angle with respect to the boot holder that is rearmost on the lever relative to the boot will not be greater than 90° and will preferably be less than 90° to help ensure that the lever is “over-center” when the rearmost boot holder is engaged with the heel of the boot.  
         [0041]      FIG. 7  illustrates the separate components of a preferred heel tensioning lever of this invention. Removable component  34  comprising heel holder  43  is shown detached from the remainder of the lever which is an integral component comprising handle  21  and heel holder  23 . The removable component may be removably fixed to the integral component by means of a suitable fastener such as a threaded fastener including a screw or bolt. In the illustrated embodiment, bolt  62  and nut  61  are employed. Pivot  22  is essentially a cylindrical through hole through the intact lever. As is shown in  FIG. 7 , curved walls of this through hole  63  and  64  are found on the integral component and the removable component respectively. Joining of the removable component  34  to the integral component with a cable or bail placed therebetween serves the purpose of establishing rotational engagement of lever  31  with the cable or bail and retains the cable or bail on the lever.  
         [0042]     The sequence of drawings shown in  FIG. 9A-9F  illustrates use of a lever of this invention. In each case, only the heel portion of the boot is shown and the same reference numerals as employed in  FIG. 1  are used to illustrate features of the boot heel. In  FIG. 9A , lever  31  is shown in a position just prior to engagement with the heel of a boot, termed the “disengaged” position. To engage the heel lever for touring mode shown in  FIG. 9B  (which facilitates walking and uphill travel), the user employs handle  21  to actuate the lever whereby the lever rotates upwards engaging boot holder  43  in lateral groove  5  of the boot. In order to do so, boot holder  43  must be forced over point  75  at the bottom of lateral groove  5  and while travelling, lever  31  will be displaced rearwards from the boot. Tension on the lever applied through bail  16  (partially shown) and spring components of the binding is negligible in the disengaged position and is higher when boot holder  43  is forced over point  75  on the boot heel. Continued movement in order that boot holder  43  engages with groove  5  then results in a lesser but significant tension thereby retaining the lever in clamping engagement with the boot heel in the walking or touring mode. A relative amount of tension in this position is illustrated by distance  100  between imaginary lines  71  and  72  in  FIG. 9B  with line  71  representing the position of the center of pivot  22  in the disengaged mode and line  72  representing displacement of the pivot center while the lever is in clamping engagement with the boot heel in the touring or walking mode. While the lever is being forced over point  75  in order to engage the touring mode, the amount of displacement would be greater than is shown between lines  71  and  72  in  FIG. 9B . In the illustrated embodiment, boot holder  23  comes to rest against the rear part of boot upper  2  adjacent the heel and the lever is now in a stable “over-center” position with bail  16  being situated above the engagement of boot holder  43  in groove  5 .  
         [0043]      FIG. 9C  and  FIG. 9D -F illustrate alternate routes for changing the position of lever  31  from the touring or walking mode illustrated in  FIG. 9B  to ski modes where greater tension is provided to facilitate turning and other downhill or gliding maneuvers on the skis. The user may immediately proceed from the position shown in  FIG. 9B  to a first ski mode shown in  FIG. 9C  by continuing to rotate lever  31  upwards by actuating handle  21 . This forces heel holder  23  downwards and against the boot so that it becomes in clamping engagement with welt  4 . In this maneuver, heel holder  43  becomes disengaged from groove  5 . Because heel holder  23  is situated at a greater distance from the center of pivot  22  than was the case for heel holder  43 , the lever is displaced further to the rear and greater tension is exerted, as is illustrated by distance  101  between imaginary line  71  and line  73 , which is greater than distance  100  in  FIG. 9B .  
         [0044]     If the user prefers to not use the welt of the boot or if the boot does not include a welt, a second ski mode may be pursued through the sequence of events illustrated in  FIG. 9D-9F . Here, the lever is moved from the tour mode position of  FIG. 9B  to the disengaged position as illustrated in  FIG. 9D . The user then lifts the heel of the boot slightly upwards relative to lever  31  so that heel holder  23  becomes adjacent to groove  5  ( FIG. 9E ). The user then rotates lever  31  upwards thereby engaging heel holder  23  in groove  5  and a high level of tension is again provided and illustrated by distance  102  between imaginary line  71  and  74  in  FIG. 9F .  
         [0045]     The inventors have found that in some tests of a heel lever of this invention in a binding assembly as illustrated in  FIG. 4  with a SCARPA™ telemark boot and standard TARGA™ spring cartridges, movement of the boot through a 30° range required as much as 30% less work in the touring mode. In this case, the boot holder minimum distance was approximately 0.75 as determined by the measurement method described above.  
         [0046]     Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of skill in the art in light of the teachings of this invention that changes and modification may be made thereto without departing from the spirit or scope of the appended claims.