Abstract:
A strap and climbing skin attachment assembly and kit comprises an elongated strap having a thickened end portion, two flat plates riveted to sandwich one end of the climbing skin, a rectangular cutout extending inward from the sandwiched end of the climbing skin between the plates, the unthickened end and body of the strap being insertable through an opening in at least one of the plates to thread the strap through the opening and between the plates until the strap is secured by the thickened opposite end engaging within the opening and in the cutout.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a system for securing a climbing skin to the bottom of a ski. In particular, the invention relates to an system for securing a climbing skin to one end of a resilient tensioning member used to affix the skin to a ski.  
         BACKGROUND OF THE INVENTION  
         [0002]    Climbing skins have been used on skis for many, many years to assist skiers in ascending slopes. Original climbing skins were made from the skins of animals. More recently, climbing skins have been made from synthetic fabrics which have a nap of stiff, rearwardly angled fibres projecting from their bottom surfaces. When the skins are attached to the skis, the skis can be slid in a forward direction relatively easily. When the skis are moved in a rearward direction then the fibres bite into the snow. By attaching climbing skins to both skis, a skier can up even a reasonably steep snow slope by sliding one ski forward and then the other.  
           [0003]    Attaching a climbing skin securely to the bottom of a ski in such a way that the climbing skin will not be easily dislodged during use and snow will not build up between the base of the ski and the climbing skin can be difficult. The problem of securely attaching climbing skins to skis is exacerbated by the fact that a skier my repeatedly put climbing skins onto skis and take them off during the course of a days skiing.  
           [0004]    Early climbing skins simply had straps which were used to attach the climbing skin to the ski. Typically straps were provided to stretch the climbing skin between the tip and tail of the ski and additional straps were provided along the edges of the climbing skin. The additional straps could be used to tie the climbing skin to the ski itself. Such climbing skins tended not to work very well because it is generally not possible to tie the skin to a ski tightly enough to prevent snow from building up underneath the climbing skin. Furthermore, the numerous straps were time consuming to attach and keep properly adjusted.  
           [0005]    More recently, adhesive climbing skins have been developed. Some adhesive climbing skins have a hook or the like which hooks over the tip of the ski. The skin is simply pressed against the ski base and is detachably held in place by a tacky adhesive. Such climbing skins provided acceptable performance when the base of the ski was dry. However, if the adhesive on the climbing skins becomes covered with snow or if the base of the ski becomes wet and has snow adhering to it then the adhesive may not properly hold the climbing skin to the base of the ski. In such cases, the climbing skin can become unstuck from the ski especially at the tail.  
           [0006]    Climbing skins which use an adhesive as well as tail and tip straps to hold it in place have also become popular. This common tail fixation method is problematic in that it is usually necessary to modify the ski to provide a way to attach a strap to the tail end of the ski. Some current climbing skin systems have a fixture, such as a pin which is screwed into the top surface of the ski near the tail. A strap from the rear end of a climbing skin can then be stretched around the tail of the ski and attached to the pin. This is not desirable because it requires modification of the ski itself.  
           [0007]    In another common tail fixation method, the skin is riveted to a pair of sandwiching metal plates that include an integral hook for engaging the tail end of the ski. Because the metal hook is relatively rigid, the strap must be moved to the tip end of the ski. Two rectangular metal wire looks (clips) are typically connected by a short (about 4 inches long) elastic, rubbery strip. The skin is fed through a portion of one of these separate clips and is looped back to adhere onto itself. The clip on the other end of the elastic strip is hooked over the tip of the ski to hold the skin in place. Having the elastic strip located at the tip can be a problem when the skier accidentally hits the wire loop with the opposite ski thereby knocking the clip completely off the tip of the ski. Once the skin is free from the tip of the ski, it can drag through the snow and the skin adhesive can become contaminated and eventually fail.  
           [0008]    The straps, or elastic tensioning members, in strap-based skin attachment systems are usually made of plastic or rubber. These systems are prone to failure due to the harsh conditions they are exposed to. The plastic or rubber tensioning members can crack and tear in extreme cold. They are also subject to chemical breakdown through radiation exposure and oxidation. The metal plate and rivet systems used for fastening to the skin fabric can tear out of the comparatively weak fabric and are extremely difficult to replace in the field. Existing tip and tail systems have not directly addressed the long-term reliability issues and repair issues often-encountered in ski touring.  
           [0009]    There is a need for an attachment system for climbing skins which allows climbing skins to be securely affixed by straps at both tip and tail ends of the ski and yet which is easy to use and does not require modification of the ski itself. There is also a need to provide an attachment system between the strap and the skin that is strong, does not tear the skin fabric and is field serviceable.  
         SUMMARY OF THE INVENTION  
         [0010]    In one of its aspects the invention is an assembly for attaching an elongated resilient tensioning member to a climbing skin. The assembly comprises a generally rectangular cutout extending inward from one end of the skin, two flat rigid plates secured about opposite faces of the end of said skin by means of a plurality of rivets extending through apertures in the plates and through the skin. At least one of the plates has an opening therethrough. The tensioning member has an elongated body portion of substantially uniform thickness. One end portion of the member has a thickness greater than the thickness of the opposite end and than the body portion, and the end portion is no longer than the length of the opening. The end portion is retained in the opening between the plates and a portion of the tensioning member adjacent the end portion extends between the plates along the cutout.  
           [0011]    In another aspect of the invention, the portion of the tensioning member that is adjacent the end portion is wider than the body portion and the width corresponds to the width of the cutout.  
           [0012]    In another aspect of the invention, there are at least three rivets on at least three sides of the cutout.  
           [0013]    In another aspect, the invention is a kit for a climbing skin system comprising an elongated climbing skin, a generally rectangular cutout extending inward from one end of the skin, two flat rigid plates secured about opposite faces of the end of the skin by means of a plurality of rivets extending through apertures in the plates and through the skin, with at least one of the plates having an opening therethrough. The kit also includes an elongated resilient tensioning member comprising an elongated body portion of substantially uniform thickness and two ends, a first of said ends having a end portion extending from said first end and having a thickness greater than the thickness of a second of said ends and greater than the thickness of said body portion, said end portion being no longer than the length of said opening.  
           [0014]    In another aspect of the kit invention, a portion of the resilient tensioning member adjacent the end portion is wider than the body portion and the width corresponds to the width of the cutout.  
           [0015]    In a further aspect of the invention, there are at least three rivets on at least three sides of said cutout.  
           [0016]    Other aspects of the invention will be appreciated by reference to the detailed description which follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    In drawings which illustrate various non-limiting embodiments of the invention:  
         [0018]    [0018]FIG. 1 is a section through a climbing skin mounting system on the rear of a ski;  
         [0019]    [0019]FIG. 2 is a top view thereof;  
         [0020]    [0020]FIG. 3 is a bottom view of the tail end of the ski, showing an attachment assembly according to the invention for attaching the skin to the strap;  
         [0021]    [0021]FIG. 4 is a cross sectional view of the skin, strap and attachment assembly according to the invention;  
         [0022]    [0022]FIG. 5 is a schematic, partially cut-away top view of a mounting system according to an alternative embodiment which has a pair of cords held in a dual-cord cord lock;  
         [0023]    [0023]FIG. 6 is a side elevation of a clip having a pin projecting from a location on its rear side;  
         [0024]    [0024]FIG. 7 is a top view of a further alternative embodiment wherein a cord is held between a pair of spring-loaded cams;  
         [0025]    [0025]FIG. 8 is a section through a further alternative embodiment wherein a strap is held by a tension lock; and  
         [0026]    [0026]FIG. 9 is a side elevation of a clip according to an alternative embodiment wherein a strap passes through an upright flange on the clip. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]    [0027]FIGS. 1 and 2 show a ski  10  to which is attached a climbing skin  12 . Elongated climbing skin  12  has a nap  13  made of rearwardly angled bristles and is attached to the base  10 A of ski  10  with a suitable removable adhesive  14 . An elongated tensioning strap  16  is affixed to the rear end of skin  12  as discussed in greater detail below. Strap  16  is affixed at the tail  10 B of ski  10  with a mounting clip  18 .  
         [0028]    Mounting clip  18  is very generally C-shaped in cross-section and hooks around the tail  10 B of ski  10 . Clip  18  has a low rigid flat portion  15  which extends underneath the base  10 A of ski  10 . Clip  18  is rigid so that it can slide onto tail  10 B of ski  10  but cannot rotate when it is on ski  10 . Strap  16  has a number of spaced apart apertures  17  in its distal portions. A user can apply tension to strap  16 , pull strap  16  around the rear end of clip  18  and then hold strap  16  in place on clip  18  by hooking one of apertures  17  around a projecting pin  20  on clip  18 .  
         [0029]    In the preferred embodiment shown in FIG. 1, clip  18  has a raised portion  21  in which is an aperture  22 . Strap  16  passes through aperture  22 . Thus, clip  18  remains on strap  16  even when skin  12  and strap  16  are removed from the ski  10 . The shape of clip  18  tends to prevent clip  18  from rotating relative to tail  10 B of ski  10  under the tension forces exerted on strap  16 . Clip  18  may be made from any suitable material such as steel or a rigid plastic.  
         [0030]    Preferably the rear portion  26  of clip  18  has a surface  26 A which is disposed at an acute angle relative to base portion  15 . Thus, when clip  18  is installed and strap  16  is under tension, the tail end  10 B of ski  10  is wedged into the rear end of clip  18  between surface  26 A and lower portion  15  of clip  18 . This tends to prevent clip  18  from sliding sideways in either direction on the tail  10 B of ski  10 .  
         [0031]    Preferably strap  16  and/or skin  12  are slightly resilient so that skin  12  and strap  16  remain under tension while in use. Strap  16  may be made from a strip of fabric-reinforced rubber, or the like. Most preferably, the rearmost end  19  of strap  16  is broadened. This both prevents the accidental removal of clip  18  from strap  16  and provides a convenient hand grip for applying tension to strap  16  when attaching skin  12  to a ski.  
         [0032]    In the embodiment shown in FIGS. 1 and 2, the strap  16  is releasably affixed to clip  18  by means of a pin  20  on clip  18  which is received through an aperture  17  in strap  16 . Other suitable means for holding the strap  16  is a tensioned manner to clip  18  may also be used.  
         [0033]    For example, the clip may include a jam lever which can be pressed down so as to hold the strap in place on the clip by compressing a strap between a cam and a surface on the clip. Jam levers are known in the art and can be readily purchased from various sources. Preferably the jam lever is installed so that tension on strap tends to tighten the cam, and thereby prevent the strap from becoming loose during use.  
         [0034]    [0034]FIGS. 3 and 4 show a novel attachment means for connecting the resilient strap  16  to the climbing skin  12 . In the preferred embodiment, two flat rigid plates  60 , fabricated from steel or other suitable materials, are positioned on the two opposite sides or faces of the skin material so as to sandwich the skin material between them. A generally rectangular cutout  61  is made in the central portion of the tail end of the skin to make room for the strap  16 , i.e. it extends inward from the tail end of the skin. Three holes are punched through the fabric to make room for the rivets  62 . In the preferred embodiment, three soft, solid rivets  62  are deformed using a press or hammer to tightly squeeze the rigid plates  60  together, thereby securely pinching the skin fabric  12 . Preferably the rivets are provided on at least three sides of the cutout  61  to maximize the integrity of the connection and to minimize fabric tear.  
         [0035]    At least one of the two plates  60  includes an opening  63  that is sized to allow the clip end of strap  16  to be fed through opening  63  as will be explained below.  
         [0036]    The end  64  of the strap that is adapted to be retained in the rivet assembly includes a thickened end portion, comprising opposed enlarged (thickened) sides  66 ,  68 . The end portion is thicker than the elongated body portion of the strap  16  which has a substantially uniform thickness, and it is thicker than the opposite end of the strap. The thickened end portion is also preferably made no longer than the length of the opening  63  so as to allow it to be seated within the opening and the cutout in order to minimize its profile against the snow or the ski as the case may be.  
         [0037]    Preferably the body of the strap  16  and the broadened clip end of the strap have a thickness of about 0.080 inches while the thickness through the combined raised portions  66 ,  68  of the strap is about 0.180 inches. It is contemplated that the combined thickness may range from 0.16 inches and 0.20 inches to achieve the objects of the invention.  
         [0038]    The portion of the strap that is adjacent the thickened end portion is broadened to a width approximately equal to the width of the cutout  61 . Once the plates  60  are assembled with the rivets  62 , the strap  16  can be fed rearward, i.e. starting at its unthickened clip end, through the opening  63  in the plates  60 . The strap  16  snaps into place and is help within the opening in the plates  60  by the dual opposing raised portions  66 ,  68  of the strap. The thickened end portion is then retained in opening  63  between the plates  60  and the broadened portion of the strap  16  that is adjacent the thickened end portion extends between the plates along the cutout  61 . It will be appreciated that the strap and skin attachment assembly can be provided as a kit for assembly by the skier, comprising the skin one end of which is provided already sandwiched between the two plates and an elongated strap  16  as described above including the thickened end portion and preferably the broadened adjacent portion matching the width of the cutout.  
         [0039]    The preferred embodiment of the strap and skin attachment assembly provides numerous advantages over the state-of-the-art skin technology. Primarily, the assembly allows for quick and easy replacement of strap  16  by the skier in the field. The skier simply slides a new strap into the plate opening  63 . In addition, the strap  16  can be designed to have a breaking tension lower than the force required to pull or tear the plates  60  from the skin  12 . The completed assembly is lightweight, thin, reliable, and easily field serviceable.  
         [0040]    Alternatively, strap  16  could comprise a cord instead of a flat strap or could comprise a flexible flat member having a cord attached to its end. Such a cord might be attached to a climbing skin by passing it around the rear end of the clip to be held in place by a cord lock device. Cord lock devices of various types are well known in the art. One type has a plug slidably mounted within a housing. The plug is biased toward one side of the housing by a spring. The cord passes through apertures in the housing and the plug and is jammed between the plug and the housing. A release button allows a user to displace the plug against the bias force exerted by the spring to release the cord. The cord lock device is preferably of a type which is designed in such a manner that tension on the cord tends to tighten the cord lock device.  
         [0041]    [0041]FIG. 5 shows a clip  18 C in which a skin  12  is tensioned on a ski  10  with a dual-cord cord lock  40 . Cords  32  pass between a wedge  42  and inclined walls  43 . Tension on cords  32  tends to pull wedge  43  rearwardly, thereby tightly gripping cords  32 . The angles of walls  43  relative to the longitudinal center of clip  18 C are exaggerated in FIG. 5. In the FIG. 5 embodiment cords  32  pass around locating grooves in the rear end of clip  18 C. Locating grooves  44  guide cords  32 .  
         [0042]    When a strap is affixed to a clip  16  by a way of a tab which projects through a hole in the strap, it is not necessary that the tab be located in the same position shown in FIGS. 1 and 2. FIG. 6 shows a clip  18 D according to an alternative embodiment wherein a tab  20 A projects generally rearwardly from clip  18 . This embodiment is not preferable because of the enhanced likelihood that strap  16  may become accidently dislodged from tab  20 A in the FIG. 6 embodiment during use.  
         [0043]    [0043]FIG. 7 shows a further alternative embodiment wherein a cord  32  which is attached to the rear end of a climbing skin passes around clip  18 E and is held in place while tensioned between a pair spring-loaded cams  46 . Larger versions of such cams are used, for example, to secure ropes on sailing boats.  
         [0044]    [0044]FIG. 8 shows a clip  18 F according to a further alternative embodiment wherein a strap  16  is held in place by a tension lock assembly  50 . Tension locks are well known and are commonly used to adjust the lengths of straps on backpacks. In a tension lock, a strap is doubled back on itself around a number of surfaces tending to resist slippage.  
         [0045]    As described above, in preferred embodiments the clip  18  is slidably disposed on the strap or cord which is attached to skin  12 . This prevents clip  18  from becoming lost when skin  12  is detached from ski  10 . The embodiment of FIGS. 1 and 2 shows the strap  16  passing through a pair slots on either side of a bend in the upper portion of clip  18 . Clip  18  could be configured in any of various alternative ways which also cause clip  18  to be slidably disposed on a strap or cord when the skin is detached from a ski. For example, FIG. 9 shows a clip  18 G wherein a strap or cord passes through an aperture  55  in a flange  56  which projects upwardly from a top surface of clip  18 G. A strap or cord could also pass through a loop of cord or elastic attached to a clip  18 .  
         [0046]    While it is not preferred, a strap  16  could also be held to the top of clip  18  by a section of hook and loop fastener material such VELCRO™, having one part on the clip and another part on the strap. A strap or cord could also be retained on a clip  18  by a snap fastener, mechanical clamp, or the like. Where a mechanical clamp is used a user could pull a strap or cord tight and then secure the strap or cord in place by turning a screw or the like.  
         [0047]    It will be appreciated that while the embodiments of the invention have been described in some detail, modifications and alterations thereto may be practiced without departing from the scope of the invention.