Patent Grant
7384057
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.
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'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.
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.
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.
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.
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.
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.
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.
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.
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).
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 another 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.
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.
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.
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.
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.
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.
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.
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°.
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.
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.
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.
The invention will now be described more particularly with reference to individual and preferred embodiments as illustrated in the attached drawings.
A modem touring or telemark ski boot 1 made from synthetic plastic materials is illustrated in
The side of lever 31 which is configured to face the rear and heel of the boot when in use is illustrated in
Lever 31 illustrated in
The sequence of drawings shown in
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
The inventors have found that in some tests of a heel lever of this invention in a binding assembly as illustrated in
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.
This application claims priority to U.S. provisional patent application 60/538,223 filed Jan. 23, 2004, the content of which is hereby incorporated by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2116969 | Cyr, Jr. | May 1938 | A |
| 4140332 | Beyl | Feb 1979 | A |
| 5318320 | Ramer | Jun 1994 | A |
| 5518264 | Broughton | May 1996 | A |
| 6267403 | Bossin et al. | Jul 2001 | B1 |
| 6308979 | Ludlow | Oct 2001 | B1 |
| Number | Date | Country | |
|---|---|---|---|
| 20050212263 A1 | Sep 2005 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60538223 | Jan 2004 | US |
