Abstract:
Improvements in snowmobile stabilizers are now available. The stabilizer comprises three parallel wear blades each of which is made to remain sharpened over a long period of time. The side blades may contain holes to divert the snow and to add roughness when engaging into a ski path, while a rectangular central part provides a blade support of a given hardness and holding a central blade of a much higher hardness, thereby permitting passage over rugged hard terrain while protecting the blade support against rapid wear. In soft abrasive gravel, the blade support wears partially thereby leaving a protruding central part, the protruding difference being self adjusting. In the case of the concave ski each side comprises a rectangular edge wear part coupled with a side blade for a total of four wear blades.

Description:
BACKGROUND—FIELD OF INVENTION  
       [0001]     This invention belongs to recreational snowmobile vehicles particularly the ones having one or more skis, and particularly snow ski provided with at least a wear runner and also a blade. This patent proposes a modification to the blade to increase the ski response in soft snowy path to procure an aggressive driving. Furthermore, the invention comprises a modification to a central runner which is self sharpening.  
       BACKGROUND—DESCRIPTION OF THE PRIOR ART  
       [0002]     The present invention is an improvement over four inventions from the same inventor so being utilized by other snowmobile skis comprising the same essential characteristics: at least a wear runner and at least a blade. The prior patents from the same inventor which the present invention refers to are the following: 
        CA 2,388,833; Snowmobile runner.     CA 2,378,638; Snowmobile ski auto-stabilizer, in M or reversed W.     CA 2,388,801; Concave ski stabilizer.        
 
         [0006]     CA 2,300,359 and U.S. Pat. No. 6,520,512; snowmobile ski stabilizer comprising a reversed U channel and a Teflon™ corrector lining the web of the U-channel to provide smooth gliding of the snow between the wings of the U-channel. Centrally of the wings is disposed an existing carbide runner which may be replaced by a self adjusting runner.  
         [0007]     A review of the prior art revealed the following patents: 
        U.S. Pat. No. 5,344,168 Olson Sep. 6 th  1994; shows a wear runner  50  provided with a carbide bar  56  of the shape of a triangular diamond. The carbide resists until its point  58  is worn more than 10% after which time it does not behave with sufficient sharpness to engage itself into sharp ice, whence the danger of side swaying, the sharp point being dull from wear and incapable of stopping swaying.        
 
         [0009]     CA 2,195,166; shows a wear runner  26  supported in 64, 66, 68 but without added carbide. The element which does the cutting is a break blade  152  which again when dull may no longer cut into the ice.  
         [0010]     U.S. Pat. No. 6,012,728; is a snowmobile ski with multiple protruding keels on its underside. The height of the steering keel gradually increases in protrusion, from front end to a central position and may reduce from central position to aft end, but is not high enough to really penetrate snow.  
       OBJECTIVES  
       [0011]     During fast turns of snowmobile skis comprising at least one wear runner and one blade, the snow pressure increases because of the presence of a central wear runner. This phenomenon creates a tendency to lift up the ski during high speed turns. The objective of the present invention is to provide an exit door to the snow by making an aperture in the blade opposite the runner The snow submitted to pressure from the runner gets out by the aperture and the ski no longer tends to lift up by excessive snow pressure. Meanwhile, the adherence of the blade during fast turns and the driving are so improved under these circumstances. To make this aperture useful it must be made oppositely to the wear runner. The wear runner refers to a runner supporting the ski and the snowmobile during passages over a hard surface. The wear runner is obligatory lower than the blade. During passage on a hard surface it is the wear runner that gets into contact with the ground, not the bottom of the blade. The aperture in the blade must be made oppositely to the wear runner otherwise if the blade were to touch a hard surface at a spot (for example a railroad track), the blade would get stuck in the aperture. Being opposite to the wear runner, the edges of the aperture do not touch the hard surface for it is the wear runner which is in contact with the hard surface. A second objective of the invention is that the wear runner be self sharpening, more particularly comprising a rectangular central blade embedded at the center of a support also rectangular and having parallel sides, the hardness of the support being inferior to the hardness of the blade so when the blade slides over a hard surface such as asphalt road, the support is prevented from wearing as long as the carbide resists. During passage in abrasive paths, the support wears more rapidly than the central carbide leaving a difference in height between the blade and the support over all the depth of the wear runner, making it self sharpening, always at a same degree, until the end of the wear out of the runner. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The present invention will be further understood from the following description with reference to the drawings in which:  
         [0013]      FIG. 1  is a perspective of a runner of the prior art.  
         [0014]      FIG. 2A  is a perspective of a constant use runner  
         [0015]      FIG. 2B  is a side view of  FIG. 2A  with partial slit.  
         [0016]      FIG. 3  is a cross-section according to line  3 - 3  of  FIG. 1 .  
         [0017]      FIG. 4  is a cross-section according to line  4 - 4  of  FIG. 2A   
         [0018]      FIG. 5  is a perspective of a ski equipped with a stabilizer.  
         [0019]      FIG. 6  is a side view of an aggressive stabilizer.  
         [0020]      FIG. 7  is a bottom view of a diagram of the ski of  FIG. 6 .  
         [0021]      FIG. 8  shows a perspective of the aggressive of  FIG. 6 .  
         [0022]      FIG. 9  shows an embodiment of the invention with a concave ski.  
         [0023]      FIG. 10  shows two independent blades and a central runner.  
         [0024]      FIG. 11  shows two blades and a runner made of one only piece.  
         [0025]      FIG. 12  is a section of a stabilizer adapted to a concave ski.  
         [0026]      FIG. 13  is a perspective of a concave ski having a stabilizer.  
         [0027]      FIG. 14  is a perspective of a ski with blades and a runner.  
         [0028]      FIG. 15  is a top view of the ski of  FIG. 14 .  
         [0029]      FIG. 15 . 1  is a section according to line  15 . 1 - 15 . 1  of  FIG. 15 ;  
         [0030]      FIG. 15 . 2  is a section according to line  15 . 2 - 15 . 2  of  FIG. 15 .  
         [0031]      FIG. 15 . 3  is a section according to line  15 . 3 - 15 . 3  of  FIG. 15 .  
         [0032]      FIG. 16  is a perspective of a replaceable runner.  
         [0033]      FIG. 17  is a section according to line  17 - 17  of  FIG. 16   
         [0034]      FIG. 18  is a perspective of a runner seen from underneath. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]     Preferred embodiments of the invention are illustrated in the figures wherein the same numbers identify the same characterizing elements.  
         [0036]      FIG. 1  shows an original runner  20  provided underneath of a carbide bar (stabilizer)  22  having a diamond point shape.  
         [0037]      FIG. 2A  shows a wear blade runner  28  in carbide having a curved part  25 , in the front, a rear beveled part  27  and comprises in the interior, a thin sided carbide  30  acting as a knife blade penetrating snow, ice and rough abrasive surface  26 . The constant thinness is to give superior driving adherence, on hard, icy snowy surfaces. In  FIG. 2A  the wear blade runner  28  in carbide may preferably be rectangular, slightly inclined and sharpened ( FIG. 4 ). In  FIG. 2B  the profile of the thin carbide  30  appears in the slit.  
         [0038]      FIG. 3  shows for prior art the original runner  20  and the carbide bar  22 . This carbide bar has a point  51 . In operation after a certain while, the end of the point wears out until a point maximum level of use  42 . The depth  44  maintains the carbide bar in position. At that very moment there is no biting by the carbide because the carbide has enlarged. A maximum wear is reached at a shoulder  46  where the cutting efficiency is null on ice or hard surface, the wearing out continuing on the runner seating surface as far as half of the runner circle. Dotted lines show the relative thinness of a proposed side carbide ( FIG. 4 ).  
         [0039]      FIG. 4  shows a wear blade runner  28  made in a rectangular shape: short sides  29 ,  29 ′ oriented top to bottom and large sides  31  disposed perpendicularly of the side of a ski. The runner  28  is of two parts, namely a support  40  of the above dimensions and a thin sided carbide  30  embedded in a sheath  32 . The sheath has a thin side  34  and two long sides  36 . Between the sheath and the flat carbide there is barely enough space to pass through a silver foil  37  to weld the carbide in place. After wear out on hard roads there is a new position  38  of the carbide; after wear out following frequent passages on abrasive paths and on icy ground filled with rocks a new position of the support  40  is found at depth  44 . The wear out position of the support  40  attaining the end of the carbide. The hardness of the support material is of 0 to 50 Rc but the hardness of the thin sided carbide  30  is of 60 to 80 Rc. A height of 1″ is possible for the large side  31 . The bolts  70  ( FIG. 2A ) serve to unify the wear blade runner  28  to the original ski. One sees a curved end  25  that is also sharp in the back  27  until the beginning of the curving part. The side carbide  30  can have typically a thickness of short side  34  of about 1/16″. It is possible to increase the thicknesses for more durability but with less efficiency. The thickness of the web  29  is twice to four times the thickness of the central carbide blade, to support well the carbide blade.  
         [0040]     In use the turning of the skis equipped with a wear runner causes the digging of a channel along the guided direction and a better adherence of 66% more than a carbide runner with diamond point when reaching the maximum level of use  42 ; ( FIG. 3 ) the utilization of the runner provided with the thin sided carbide  30  being the third of the original carbide bar  22  procures much more adherence and less friction when sliding. The overlapping of the point creates an excess  41  corresponding to 1/16″ of sliding depth in the ice so the overlapping of the original carbide bar corresponds to ¼″. As well, the wear blade runner itself corresponds to ¼″ to 3/16 large but the original runner is 7/16 to ½″ large and round. A round runner does not offer a cutting easiness but gives more resistance when sliding, especially for its largeness ( 7/16″) is almost the double of the wear blade runner  28 . All restriction to sliding by a large runner causes way less adherence, less cutting easiness, a loss of speed, an increase in gas consumption, what is not useful for the consumer. Therefore, it is preferable to add a blade bevel  45  at the end of the blade, combined with a runner bevel  43  at the end of the runner.  
         [0041]      FIG. 5  shows the underside of a snowmobile ski  120  in—dotted line—, fitted with a stabilizer  122 . The stabilizer  122  starts on the rear end, just before the curved part  124 , and stretches to the front end  126  of the ski  120 , just before a strong curve  128 . The stabilizer  122  is placed on a lowered center channel  130  located in the middle of two carrying sides  132 . The lowered center channel  130  receives a carbide bar  122  that protects the ski when sliding over asphalt. The carbide bar  122  also helps veering when moving on icy surface. The stabilizer  122  has a U-shaped section  136  with wings  138 , pointing downward, in order to penetrate snow. Section  136  is made of metal. A corrector  140  is placed on a web  142  of the U-.shape section  136  and comprises a bend  144 . A resilient section  141  bears against the front end of a steel stabilizer  122  when the front end  126  of the ski is bent. The corrector  140  may be made of Teflon™ or Tivor™ type material or of UHMW polyethylene plastic. Front and back bolts  146 ,  147  fix the corrector  140  and the stabilizer  122 . The wings  138  are two (2) to three (3) mm thick, preferably 2 mm and are 19 mm high. The corrector  140  has an extension  150  at the front and stretches to the front end  126  of the ski.  
         [0042]     It is possible to use an L-shaped channel with the short part of the L replacing a wing of the U but it is preferable to have the carbide bar  134  located between the two wings  138 . The carbide bar  134  not only protects when crossing on asphalt roads but facilitates turning when on icy roads because it supports the ski on a single point. A typical height of wing  138  is 18 mm with variations from 6 to 50 mm. The width of the web  142  may be from 25 to 150 mm with typical value at 40 mm. The carbide bar  134  may be of different lengths in order to fit the skis being used by a snowmobile manufacturer. The wings may be covered by carbide plates  152  such as appears on one wing or by a spread of carbide or diamond powder  153  such as is shown on the second wing.  
         [0043]      FIG. 6  shows an aggressive snowmobile ski  220  comprising a ski support  231 , a blade  230  provided with an aperture  234 , and a wear runner  228 . One sees also the wear runner  228  exceeds the blade  230  and the blade point  238 . This way the runner is lower than the blade; the blade will rub to a hard surface, but the blade point  238  will stay upwards. It is obligatory that the ski of the present invention be provided with such a wear runner where the blade point  238  or a rear edge  232  of the aperture would be damaged by crossing for example a railroad track. The aperture is formed of the rear edge  232 , the front edge  240 , and can also be formed of a superior edge localized between the blade point  238  and a blade support leaning on a ski. The direction of the snowmobile  222  is also illustrated that is why the angle of the rear edge  232  is less inclined than the front edge, the front edge could be cut at 90° so be the rear edge could be at 90° to facilitate the passage of rocks or other hazards. In the present illustration, the aperture corresponds to the total width of the blade  242 , that is why there is no superior edge. Such opening width is preferable because it gives less resistance to the exiting of the snow in sudden turns.  
         [0044]      FIG. 7  shows the aggressive ski in action. The ski slides on the snow  224 , the front appearing at the left. When the wear runner  228  gets into contact with snow, the snow is compressed on all the height of the blade  230  including the rear edge  232  in slope and the pressure can provoke a slight lifting of ski. In the shown ski, the apertures  234  permit the evacuation of snow. The snow pressure under the ski is re-established and the ski will no longer have the tendency to lift. This compensation effect can be compared to the aquaplane effect under tires of motor vehicles.  
         [0045]      FIG. 8  shows an embodiment of the invention on a snowmobile ski provided with a steering stabilizer  246  (CA 2,300,359, of the same inventor), wherein a snowmobile ski  244  is shown in—dotted lines—. One sees an aperture  234  practiced in the blade  230 , and the aperture is situated opposite the wear runner  228 .  
         [0046]      FIG. 9  shows an embodiment of the invention to a concave snowmobile ski provided with a concave ski stabilizer  248  (CA 2,388,801, of the same inventor), wherein a concave ski  250  is shown in phantom lines. One sees an aperture  234  practiced in blades  230 , and the aperture is oppositely located to the runner. The rear edge is rounded instead of showing a 45″ slope. In the case of the concave ski, the evacuation of snow is made towards the inside of the ski; the pressure of snow is decreasing for the concavity yielding a greater volume.  
         [0047]      FIG. 10  shows an independent blade  230 , separated by the runner  228  and mounted on a support  231  which is the sliding part of a ski.  
         [0048]      FIG. 11  shows blades  230  and a central runner  228  all incorporated in one piece bolted on the ski. One sees the aperture oppositely to the central runner.  
         [0049]      FIG. 12  shows each side of the concavity  352  towards the left of a cut reversed U-section forming a web  360  and a blade  358  making a pair with a right reversed U forming a web  360  and a blade  356 . A pair of carbide runners  328  appears to the receptacle limits  354  and to a web  360  under a ski. The carbide runner is attached with bolts  370  and comprises a support  340  and a thin sided carbide  330 . The support comprises a large side  331  and a short flat side  329 , wherein there is a sheath  332  containing the thin sided carbide  330 . One sees the wear out position, either the carbide position  338  or the position of the support  340 . The support is built in softer steel such as 50 Rc and permits to disengage faster than the carbide at 80 Rc to allow the carbide to be always out, ready to cut. One sees between the position of the sheath  332  and the position of the large side  331  a silver foil  337  to weld the carbide to the support. The exceeding carbide  367  protects the blade  358 ,  356  when it slides on a hard surface as asphalt, and keeps the cut helping the runner  328  to turn in digging in a rough or rugged surface until the wearing out of the carbide and then the support at its turn, is altered by abrasion. An active member  362  meant to draw a furrow in the snow by means of a marker  364  located at its bottom end. The carbide runner can endorse several shapes. It can be round, hexagonal, square or rectangular such as shown. The bolt  370  passes through the wing  323 . There is a hole in the web permitting the passage of the bolt. When the bolt is welded to the runner, it passes the web into the receptacle, through the wing to reach the ski.  
         [0050]      FIG. 13  shows a typical ski  371  possessing bearing sides. The wings  323  are typically 1″ thick, 45″ long and ¾″ large. The blade  356  is placed at an angle of about 80 to 90° and is overhang by the web along all the sliding distance of the ski, about 24″. The bolts serve to join the moveable runner to the concave ski  371 . A curved end  325  is also sharp; and correspondingly at the back until the curved part.  
         [0051]     It is possible to increase the thickness for more durability but with less efficiency. The web thickness is corresponding to the blade for it may come from the same curved part. The three pieces, the web  360  and the internal blades  356 ,  358  come from tempered steel at 30 to 60 and preferably 50 Rc. The runner is bolted  370  to the web and to the ski and it is preferably of the self adjusting type. The concavity constitutes a dome space permitting the evacuation of the snow moved by the blades.  
         [0052]      FIG. 14  shows the bottom side of a snowmobile ski  420  having sides  422  and a thick central section  424 , provided with a curved part  425  at the front. A pair of external knives  426  appears at the limit of the central part  424 . These knives end at a beveled front  428  and a straight rear  430 . The central part  424  receives a central runner  432  protecting the ski when sliding on a hard surface. The central runner  432  helps also the turning on icy or snowy surfaces.  
         [0053]      FIG. 15  is split into cuts  15 . 1 ,  15 . 2  and  15 . 3 . In the embodiment of  FIG. 15  shows a central runner  432  taking different shapes. It can be round, square, hexagonal or rectangular. The ski possesses bearing sides  434  typically of ¼″ thick, 45″ long and 1¼″ large. The thickened section  424  includes two slope sides  436  of approximately 1″ long of each side to bind to a flat part  440  that supports a runner. This runner can be overhang by a carbide runner to form a hard foot  438 . The knife  426  is placed at an angle of 80° and comes into the sheath  441  receiving a blade  426 ′ inclined. The knife  426  possesses a low limit  447 . A thickened region  424  comprises also a side  442  at 90° with a bearing side. A height of ¾″, is possible between an edge  444  and a bearing side  434 . A top  446  is relatively flat but for the external reinforcements  448  disposed above and toward the exterior. A central reinforcement  450  is disposed centrally and oppositely the central runner  432 . Pockets  452  disposed near the central reinforcement  450  help to make the structure lighter. An aluminum U- channel  454  is disposed on the top  446  and join the reinforcements  448 ,  448 ′,  450  to strengthen the ski. The U channel  454  has plies  456  joining the external reinforcements  448  by means of bolts and rivets  458 . A knife attach  460  takes the shape of a bolt, penetrates the U-channel  454  and the thickened region to reach the knife blade by a cavity  462  wherein passes a welded bolt to a place on the knife. This is repeated in various places to give the knife the strength to maintain in place.  
         [0054]      FIG. 16  shows an original ski  464  comprising a pair of wing parts  466  and a low part  468 . A low corner  470  defines a limit between a low flat part  468  and a curved part  469  forming a bearing part joining the wing part  466 . A moveable runner  472  from fore to aft ends is disposed on the sliding part of the ski and particularly under the low part  468 . Bent blades  476 ,  476 ′ are disposed towards the exterior and a central wear runner  478  is welded to a web  474 . The central wear runner can be slightly sharpened towards the bottom or take a rectangular shape. Between the central wear runner  478  and a bent blade  476 , there is a sharp angle  475  forming a sharp interior of a M. Nuts  477  serve to unify the moveable runner  472  to the original ski  464 . A succession of deformities creating central plates  494  ( FIG. 17 ) in the central line of the moveable runner  472  oppositely to the bolts to position to a bolt head  502  to ( FIG. 18 ). One sees a curved end  480  which is also sharp and similarly to the back until the beginning of the curved part.  
         [0055]      FIG. 17  shows an original ski which was added the original runner  472 . In looking at the moveable runner one sees an aperture  482  about 2¾″ and a sharpening slope  484  of about 80° to give a reversed W shape look. The slope can also be of 90° in case of a simple M. The knife can also have thickness  488  of 1/16″. It is possible to increase the thicknesses for more durability but less efficiency. The web thickness  492  is of same caliber of the knife because it may come from the same curved metal part. The web and the external knives, come from tempered steel at 30 to 60, preferably 50 Rc. The central runner  478  comprises a hard foot  438  such as  FIG. 4  runner  28  and carbide  30 , the runner being welded through the web and to the central plate  494  to prevent wear out of the weld. Central plates  494  are large enough to receive the flat part of the bottom of the ski  468  which can be 1¼″ large where it has bolts. The web  474  is ended by a turned up point  496  defining a V space to let pass the snow moved by the central runner. At a limit, the web could be slightly concave or even flat, but if it would become convex it would mean a loss of efficiency for the portion of the useable surface to place the snow during passages of the central wear runner  478  would not be large enough. The area of the runner may be ½″ long by 5/16″ wide. At the end of the central runner it may appear a sharpening  490  to give more penetration. The central runner acting as a blade can be equal or lower than the knives because in use it will wear out until the three blades  488 ,  488 ′,  478  are equal in height for they are equally used for a better cutting efficiency. A carbide  438  helps protecting from wearing out; the knives  426 ,  426 ′ which support the central runner  478 .  
         [0056]      FIG. 18  shows a moveable runner  472  seen from the bottom turned upside down: one sees a number of slits  500  to receive bolts and one perceives also a flat piece  502  and a hidden bolt head  503 . At the front the bolt has an observable bolt head  504 . A hole  505  is drilled to fix, by means of a bolt, the end of the moveable runner.  
       SUMMARY  
       [0057]     A self sharpening runner meant to be fixed to a slide ski face, the self sharpening runner comprising: 
        a rectangular wear blade runner  28  having a short side  29  oriented upward on the slide ski face, two large sides  31  disposed perpendicularly of the slide ski face and a low short side  29 ′ oriented downward against the ground, the low short side comprising a sheath  32 , the wear blade runner having a first hardness;     the sheath having two parallel sides placed from the slide face until a depth  44 , the sheath receiving a blade  30  having an excess  41  comparing to the slide ski face and having a second hardness higher than the first hardness so when the self sharpening runner travels on a hard surface as asphalt or ice, only the blade is in contact and exposed to wearing out, but when the self sharpening runner travels on a penetrable surface as snow blend with salt, sand, or gravel, the blade penetrate the surface and the blade support is also exposed to abrasion;     successive passage of the blade  30  and the sliding ski face on a hard and abrasive surface as asphalt roads causing partial abrasion only on the blade and the passage of the blade and the sliding ski face on abrasive matter a little less harder causing penetration of the blade, its wearing out, and meanwhile the wearing out of the low short side of the blade support of the first hardness; for the first hardness of the blade support is inferior to the blade hardness, the excess  41  which is responsible for an efficient cut in the hard matter is maintained until complete wearing out of the blade when a ratio of the first hardness compared to the second hardness is chosen for successive passages on hard abrasive surface and penetrable surface, completing a self sharpening and a constant and even cut until complete wearing out.        
 
         [0061]     The wear blade runner is of a thinness permitting a penetration of its rectangular shape in trail hard snow and the blade is about 2 mm smaller than the low short side and possesses a thinness making a sharp knife in an ice trail meant to create a deep furrow and to procure an efficient direction while driving until complete wearing of the runner.  
         [0062]     The self sharpening runner having a hardness ratio of the blade comparing to the support between 1.3 and 2.4. When mild steel is used in the support the carbide blade must be at least 50 Rc.  
         [0063]     The thickness of the blade being a third of the width of the wear blade runner.  
         [0064]     The blade is about 2 mm large, when the wear blade runner is about 6 mm.  
         [0065]     The self sharpening runner used in combination with a stabilizer  122  having a front  126  and a long body installed longitudinally under the slide ski surface, the stabilizer comprising: 
        a pair of cutting elements comprising two thin blades disposed externally of the snowmobile ski runner, all three elements being positioned below the ski, with the centre element comprising means for bearing over hard passages for preventing wear of the thin blades,     stabilizer comprising means at the front  126  to flatten snow between the two thin blades,     the stabilizer comprising a slide surface for longitudinal sliding between the two blades;     the combination of the three cutting elements in the flattened snow forcing the snow along the longitudinal sliding, thereby diminishing side swaying.        
 
         [0070]     The self sharpening runner used in combination with: 
        a snowmobile ski  220  comprising at least a blade  230  and at least a wear runner  228 , the blade comprising at least an aperture  234 , the aperture situated oppositely or slightly towards the front or towards the back of the runner when seen from the side.        
 
         [0072]     A method to improve the adherence of snowmobile skis having at least a runner and at least a blade during fast turns comporting at least the following step: 
        creating at least an aperture oppositely of at least a runner in at least an existing blade.        
 
         [0074]     A snowmobile ski  220  having at least a blade  230  having a width  242  having a blade point  238 , the ski comprising at least a wear runner  228 , the blade comprising at least an aperture  234 , the aperture located oppositely the runner or slightly towards the front or towards the back if seen from the side.  
         [0075]     The snowmobile wear runner used in combination with two blades  230  carrying apertures  234 .  
         [0076]     A method to improve the adherence of snowmobile skis during fast turns the method comporting the following steps: 
        installing at least a runner  228  and at least a blade  230 , the blade comprising a largeness  242  and a blade point  238 , the runner comprising a carbide point  239  disposed lower than the blade point,     practice an aperture  234  in the blade oppositely the runner.        
 
         [0079]     In a concave ski  371  comprising a sliding length and a width comprising a concavity  352  and two bearing wings  323 ), one on each side of the concavity and spread along the sliding length, the bearing wings comprising each a runner  328 , a stabilizer comprising: 
        at least a blade  358  disposed vertically and comprising means to adapt inside the concavity, the blade meant to create a path which added to the runners  328 , producing at least three parallel furrows.        
 
         [0081]     The snowmobile ski runner used in combination with a concave ski  371  comprising a stabilizer comprising: 
        at least a blade  356 ,  358  disposed vertically and comprising means to adapt inside the concavity, the blade meant to create a path which added to the runners  328 , produces at least three parallel furrows.        
 
         [0083]     The snowmobile ski runner used in combination with a snowmobile ski  420  having a sliding side comprising a thick central section  424  and a bearing wing  434  disposed longitudinally on each side of the thick central section, the central section comprising: 
        a central runner  432  under which is fixed a hard foot  438 ,     a smooth face oriented from the central runner towards the top at an angle from 0 to 60° and prolonging on both sides of the central runner on a short distance in direction of the wings and ending on each side by an edge  444  delimitating an exterior side,     two longitudinal knife blades  426 ,  426 ′ having a low cutting limit  447  and localized in the smooth face near the edge,     means of retention  460  to give rigidity to each the knife blade to allow the knives to make paths in the snow, the hard foot being sensibly at the same level as the low cutting limits, permitting to create three close furrows of equal depth in the snow.        
 
         [0088]     The self sharpening central runner localized half-way between the blades and held by slope sides  436  forming a sharp angle with the blade  426 , a section of the ski defining a structure in M for the blades  426 , the slopes  436  and the hard foot  438 , the combination of the blades and the hard foot defining three blades  426 ,  438 ,  426 ′ making three furrows at a time and the slopy part  436  serving in reserve for cutting snow by the central runner  432 ,  438 , the blades being oriented to 80±5° from the horizontal when the three blades  426 ,  438 ,  426 ′ are moved on a hard surface, the blades in slopes being sharpened on the outside.  
         [0089]     A moveable runner  472  having a M or a reversed W shape meant to be added to an existing ski to make it self stabilized, the existing ski comprising in section a low part  468 , two wing parts  466  situated one at the left and the other at the right of the low part, two angled parts  469  situated between the low part and either one or the other wing part the moveable runner  472  comprising: 
        a concave web  474  comprising a central plate  494  and two turned up points  496 ;     means to unify the central plate  494  to the low part  468  of the ski;     the moveable runner  472  comprising also at the end of the points  496  two knife walls  488  directed towards a low cutting limit  447 ;     a central runner  478  disposed under the central plate  494  and between the knife walls  488  of sensibly equal depth to the low cutting limit  447 , the central runner being sharpened.        
 
         [0094]     A self sharpening runner used in combination with a snowmobile ski comprising a principal body having a superior part and an inferior part; 
        a central swelling extended longitudinally at the level of the inferior part and covering less than half less of the inferior part and being ended by a pair of edges;     first and second knife blades localized in the central swelling, near the edge, the first and the second blades having cutting sides and the swelling having a bottom possessing centrally a carbide runner, so when the ski gets into contact with a snowy surface, the bottom, the carbide runner and the first and second knife blade being aligned to closely define an M.        
 
         [0097]     The self sharpening runner is sharpened when the snowmobile crosses a road. The road has a gravel side and a hard asphalt center. When passing over gravel both the blade and the support wear mostly the support. On asphalt only the blade wears, the amount of the excess  41  and protects the support as far as the depth  44 .  
         [0098]     It is well accepted that the embodiment of the present invention which was described above, in reference to the matched drawings, was given indicatively and certainly not limitative, and that modifications and adaptations could be brought without moving away from the object of the present invention. Other embodiments are possible and limited only by the scope of the appended claims.  
                                               LEGEND                           20-Original runner           22-Carbide bar           25-Curved part           26-Abrasive surface           27-Beveled part           27-Back           28-Wear blade runner           29-Short side           29′-Short side           29-Web           30-Thin sided carbide (Blade)           31-Large side           32-Sheath           34-Thin side           36-Long side           37-Silver foil           38-New position           40-Support           41-Excess           42-Maximum level           of wear           43-Runner bevel           44-Depth           45-Blade bevel           46-Shoulder           51-Point           70-Bolts           120-Ski           122-Stabilizer           124-Curved part           126-Front end           130-Lower center channel           132-Carrying sides           134-Carbide bar           136-U shaped section           138-Wings           140-Corrector           141-Resilient section           142-Web           144-Bend           146-Front bolt           147-Back bolt           150-Extension           152-Carbide plates           153-Diamond powder           220-Agessive ski           222-Snowmobile           224-Snow           228-Wear runner           230-Blade           231-Ski support           232-Rear edge           234-Aperture           238-Blade point           240-Front edge           242-Largeness of blade           244-Ski           246-Steering stabilizer           248-Concave ski stabilizer           250-Concave ski           323-Bearing wings           325-Curved end           328-Runner           329-Short flat side           330-Thin sided carbide           331-Large side           332-Sheath           337-Silver foil           338-Carbide position           340-Support           352-Concavity           354-Receptacle limits           356-Blade           358-Blade           360-Web           362-Active member           364-Marker           367-Exceeding carbide           370-Bolts           371-Concave ski           420-Ski           422-Sides           424-Thick central section           425-Curved part           426-External knife           426-Blade           428-Beveled front           430-Straight rear           432-Central runner           432-Rear runner           434-Bearing wings           436-Two slope sides           438-Hard foot           440-Flat part           441-Sheath           442-Side           444-Edge           446-Top           447-Low cutting limit           448-External reinforcements           450-Central reinforcements           452-Pockets           454-Aluminum U-channel           456-Plies           458-Bolt rivets           460-Knife attach           462-Cavity           464-Original ski           466-Wing parts           468-Low parts           469-Angled part           470-Low corner           472-Moveable runner           474-Web           475-Sharp angle           476-Bent blades           476′-Bent blades           477-Nuts           478-Central wear runner           480-Curved end           482-Aperture           484-Sharpening slope           488-Knife walls           490-Sharpening           492-Web thickness           493-Weld           494-Central plates           496-Turned up point           500-Slit           502-Flat piece           503-Hidden bolt head           504-Observable bolt head           505-Hole