Abstract:
A gliding edge profile for winter sports equipment, such as 7  for example, skis, snowboards and sledges, includes two component parts connected at an angle to one another along their longitudinal edges. The component parts are made of different materials to suit their properties to the stress at hand and can be joined together by laser beam welding, electron-beam welding or plasma jet welding so as to hardened and/or tempered at least in the area of the welding seam.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]    This application claims the priority of German Patent Application Serial No. 101 23 674.3, filed May 16, 2001, pursuant to 35 U.S.C. 119(a)-(d), the subject matter of which is incorporated herein by reference. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to a gliding edge profile for winter sports equipment, such as, for example, skis, snowboards and sledges.  
           [0003]    Profiles of this type are normally made of steel and exhibit a generally L-shaped cross section with a relatively greater leg and a relatively smaller leg. The leg of greater cross section has the gliding edge and terminates flush with the bottom of a ski, whereas the leg with smaller cross section provides an anchor of the gliding profile between the runner base and a runner base underlayer. Accordingly, the anchoring leg and the gliding edge leg are exposed to different stress conditions. The gliding edge leg is subjected to particular stress that requires a high degree of wear resistance, hardness and surface quality. Another important factor to consider here is maintenance-free construction because the service life decreases when the edges are sharpened as is typically done to remove rust or to re-establish good guide properties. Despite a high wear resistance, it should be possible to easily grind the gliding edge leg to a level of the runner base surface to realize a completely flat running surface. The other leg of the edge profile, serving as anchoring profile, is subjected to much less stress because it is disposed inside the ski and therefore does neither come into contact with the atmosphere nor with snow or ice or with dispersed grit and partially snow-free ground.  
           [0004]    In view of their particular stress profile, chromium steels are especially useful as material for gliding edges. Although chromium steels show high corrosion resistance and wear resistance as well as high hardness, their relatively low ductility is disadvantageous. In order to permit production of gliding edge profiles through rolling or drawing, quenchable and temperable steels are typically used which receive their wear resistance and hardness through a final heat treatment.  
           [0005]    German Patent Document DE 40 00 744 describes a process for the heat treatment of gliding edge legs in situ, whereby the zone about the gliding edge is heated locally by means of a laser beam to a hardness temperature and is subsequently immediately locally quenched to transform into a martensite structure. This process requires a complex apparatus and still cannot ensure reproducible properties of the gliding edge. In order to realize the required hardness temperature while still preventing ingress of heat into the depth of the gliding edge, particular measures are necessary, in addition to local quenching, to carry off heat which is generated during welding. This process is capable to produce a gliding edge with high hardness and wear resistance in the area of the actual gliding edge as well as comparably high toughness, especially of the anchoring profile. Still, as a consequence of the required cooling action during the heat treatment, inner tension is encountered in the edge-near region to lead to a so-called sickle distortion, i.e., a highly disadvantageous flexure of the gliding edge profile.  
           [0006]    In order to counter this sickle formation, German Patent Document DE 42 18 099 A1 limits the hardness gradient across the cross section and length of the gliding edge profile to less than 2 HRC. The process described therein employs thus a two-step heat treatment which involves a quenching and tempering of the entire gliding edge profile to provide a martensitic structure, and a subsequent partial pearlitization at a temperature as constant as possible across the length of the profile. Any sickle distortion remaining after the partial pearlitization is eliminated through a subsequent deformation by bending with constant degree of bending stretching over the length of the profile. This process is extremely complicated and still is unable to provide the gliding edge profile with the necessary corrosion resistance to eliminate the need for frequent re-grinding and sharpening.  
           [0007]    Another approach to eliminate the need for a complicated apparatus in order to implement a particular heat treatment, and the need for a frequent re-grinding, is disclosed in German Patent Document DE 198 08 276 which describes the use of a gliding edge material of chromium steel alloy. The hardness and wear resistance as well as vibration behavior and corrosion resistance depends in the quenched and tempered state, in particular toward chlorides and nitrates, on the presence of carbon, nitrogen, molybdenum and chromium.  
           [0008]    However, for a number of reasons, the various proposals are endowed with drawbacks and shortcomings relating for example to manufacturing techniques or to the effect that is hoped to be obtained but may not always be realized.  
           [0009]    It would therefore be desirable and advantageous to provide an improved gliding edge profile which obviates prior art shortcomings and is easy to make while still being reliable in operation.  
         SUMMARY OF THE INVENTION  
         [0010]    According to one aspect of the present invention, a gliding edge profile for winter sports equipment, includes two component parts connected at an angle to one another along their longitudinal edges.  
           [0011]    The present invention resolves prior art problems by providing two component parts which can be made of different materials and are interconnected to form, for example, a L-shaped configuration, whereby one component part is the gliding edge leg and the other component part represents the anchoring leg. Thus, it is possible to make the gliding edge leg of rust-free material and wear-resistant material, preferably chromium steel, whereas the anchoring leg may be made of a simple carbon steel.  
           [0012]    The gliding edge leg may be a chromium steel with  
           [0013]    0.1 to 1.1% of carbon  
           [0014]    4.0 to 18% of chromium  
           [0015]    0.1 to 4.0% of molybdenum and/or  
           [0016]    0.1 to 2.4% of vanadium and/or  
           [0017]    up to 3.0% of tungsten  
           [0018]    up to 2.0% of manganese  
           [0019]    up to 2.0% of silicon  
           [0020]    the balance being iron.  
           [0021]    Currently preferred is a chromium steel which contains at least 0.1% of tungsten, 0.4% of manganese and 0.4% of silicon.  
           [0022]    A currently particularly suitable chromium steel includes 0.3 to 1.0% or also at most 0.8% carbon, 5.0 to 16.5% or also 13.0% chromium, 1.0 to 2.0% molybdenum, 0.4 to 2.0% vanadium, 0.6 to 1.1% % silicon, as well as, optionally, 1.2 to 2.5% tungsten.  
           [0023]    A particular high wear resistance is achieved when the content of carbon, chromium and molybdenum, and, optionally, also the content of molybdenum, vanadium and tungsten, satisfies the following condition:  
           [0024]    (%C)/(%Cr)+(%Mo)=0.02 to 0.07, and/or  
           [0025]    (%C)/(%Cr)+(%Mn)+(%Mo)+(%V)+(%W)=0.65 to 0.98.  
           [0026]    Production of a gliding edge profile made of two simple component parts through a cold-rolling, drawing or roll-forming process overcomes the limits as encountered during manufacture of a L-shaped profile as far as the respective cross section of the profile leg is concerned. In this way, it is especially possible to construct the anchoring leg in comparison to conventional gliding edge profiles with, for example, a 50% reduction in thickness and a greater width to realize a better anchoring in the body of the ski. Moreover, it is also easily possible to fabricate the component parts by simply cutting respectively dimensioned bands to size or severing respective strips from a metal sheet.  
           [0027]    Joining of the component parts or profile legs can be realized through laser beam welding, electron-beam welding or plasma jet welding. In this way, heat is introduced in a narrow locally restricted area so that the heat impact zone is small. Tempering may follow the welding process to eliminate structural changes and also welding tension accompanying the welding operation in the heat impact zone.  
           [0028]    The component parts may be properly guided by a profile guide for correct positioning during welding operation. Suitably, the component parts are welded together by a welding seam at a maximum width of 0.5 mm. In this way, welding heat is small enough to realize a rapid cooling already in the area of the profile guide so that a distortion of the finished glide edge profile as a result of heat and undesired structural changes in the area of the gliding edge are prevented.  
           [0029]    A gliding edge profile may finally be subjected also to a common quenching and tempering treatment. Another option involves the production of the gliding edge leg from an already hardened component part, for example, a square wire so that there is only a need to quench and temper the complete gliding edge profile after the welding operation.  
           [0030]    According to another feature of the present invention, the welding seam may have gaps to improve the bending capability of the gliding edge profile. Such gaps or breaches can be realized by simply cutting the welding current. The bending capability can be further enhanced, when forming the anchoring leg with openings which may or may not be open toward the welding edge or welding seam.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0031]    Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:  
         [0032]    [0032]FIG. 1 is a cross section of a first embodiment of a gliding edge profile according to the present invention;  
         [0033]    [0033]FIG. 2 is a cross section of a second embodiment of a gliding edge profile according to the present invention;  
         [0034]    [0034]FIG. 3 is a cross section of a third embodiment of a gliding edge profile according to the present invention;  
         [0035]    [0035]FIG. 4 is a fragmentary perspective illustration of a fourth embodiment of a gliding edge profile according to the present invention; and  
         [0036]    [0036]FIG. 5 is a fragmentary perspective illustration of a fifth embodiment of a gliding edge profile according to the present invention.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0037]    Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.  
         [0038]    Turning now to the drawing, and in particular to FIG. 1, there is shown a cross section of a first embodiment of a gliding edge profile according to the present invention, including an anchoring leg  1  for attachment of the gliding edge profile in the body of a ski (not shown), and a gliding edge leg  2  of rectangular cross section and forming a gliding edge  3  for the ski. The anchoring leg  1  and the gliding edge leg  2  are connected together by a welding seam  4 . FIG. 2 shows a gliding edge profile in which the gliding edge leg  2  has an inner flank  5  which is inclined inwardly toward the anchoring leg  1 , whereas FIG. 3 shows a gliding edge profile in which the gliding edge leg  2  has an outer flank  6  which is inclined outwardly away from the anchoring leg  1  and forms with the gliding edge  3  a slight angle.  
         [0039]    [0039]FIG. 4 shows another embodiment of a gliding edge profile in which the anchoring leg  1  is formed with openings  8  (only one opening  8  is shown here by way of example) and openings  11  (only one opening  11  is shown here by way of example) to improve attachment of the edge profile to the body of the ski. The openings  8  have a closed border  9  whereas the openings  11  are open toward the free leg edge  10  of the anchoring leg  1 .  
         [0040]    [0040]FIG. 5 shows an embodiment of a gliding edge profile in which the anchoring leg  1  is formed in addition to the openings  8  with openings  12  which are open toward the welding seam  4  and the gliding edge leg  2 , as indicated by reference numeral  15 . Of course, it is also possible to make a gliding edge profile in which the anchoring leg  1  is formed with any combination of the openings  8 ,  11 ,  12 .  
         [0041]    As further shown in FIG. 5, the welding seam  5  is breached in addition to gap  15  by gaps  14  which divide the welding seam  5  into several weld sections  13  and are aligned with the gap  15  of opening  12  of the anchoring leg  1 .  
         [0042]    The openings  8 ,  11 ,  12  in the anchoring leg  1  and the gaps  14  in the welding seam  4  provide the gliding edge profile with a high bending capability so that the ski exhibits a high elasticity.  
         [0043]    The gliding edge leg  2  may be a chromium steel of a following composition, by weight percent: 0.1 to 1.1% of carbon, 4.0 to 18% of chromium, 0.1 to 4.0% of molybdenum and/or 0.1 to 2.4% of vanadium and/or up to 3.0% of tungsten, up to 2.0% of manganese, up to 2.0% of silicon, the balance being iron. Currently preferred is a chromium steel which contains at least 0.1% of tungsten, 0.4% of manganese and 0.4% of silicon. A currently particularly suitable chromium steel includes 0.3 to 1.0% or also at most 0.8% carbon, 5.0 to 16.5% or also 13.0% chromium, 1.0 to 2.0% molybdenum, 0.4 to 2.0% vanadium, 0.6 to 1.1% % silicon, as well as, optionally, 1.2 to 2.5% tungsten.  
         [0044]    A particular high wear resistance is achieved when the content of carbon, chromium and molybdenum, and, optionally, also the content of molybdenum, vanadium and tungsten satisfies the following condition:  
         [0045]    (%C)/(%Cr)+(%Mo)=0.02 to 0.07, and/or  
         [0046]    (%C)/(%Cr)+(%Mn)+(%Mo)+(%V)+(%W)=0.65 to 0.98.  
         [0047]    The following table indicates chromium steel alloys K1 to K6 which, apart from the chromium steel allow disclosed in German Pat. Document DE 198 08 276 A1, are suitable as material for the gliding edge leg, wherein designations F 1  to F 5  indicate materials for the anchoring leg:  
                                                                                                                                       Chemical Composition [weight %]                Al-   C   Si   Mn   Cr   Mo   Ni   V   W           loy   (%)   (%)   (%)   (%)   (%)   (%)   (%)   (%)                    K1   0.36   1.10   0.40   5.00   1.30   —   0.40   —   Gliding                                           Edge Leg 1         K2   0.38   0.40   0.60   16.0   1.00   0.80   —   —   Gliding                                           Edge Leg 1         K3   0.46   0.40   0.40   13.0   —   —   —   —   Gliding                                           Edge Leg 1         K4   0.53   0.90   0.50   8.30   1.20   —   —   1.20   Gliding                                           Edge Leg 1         K5   0.90   0.50   0.40   17.5   1.10   —   0.10   —   Gliding                                           Edge Leg 1         K6   1.00   0.40   0.40   4.00   2.70   —   2.40   2.90   Gliding                                           Edge Leg 1         F1   0.04   0.50   1.40   18.5   —   9.50   —   —   Anchoring                                           Leg 2         F2   0.05   0.40   0.40   16.5   —   —   —   —   Anchoring                                           Leg 2         F3   0.15   0.20   0.50   —   —   —   —   —   Anchoring                                           Leg 2         F4   0.38   0.40   0.60   16.0   1.00   0.80   —   —   Anchoring                                           Leg 2         F5   0.69   0.30   0.70   —   —   —   —   —   Anchoring                                           Leg 2                                    
 
         [0048]    While the invention has been illustrated and described as embodied in gliding edge profile, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.  
         [0049]    What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents: