Snowmobile steering ski

Abstract

An improved snowmobile steering ski attachable to the steering spindles of a snowmobile and, generally, including a frame, which may be integrally molded as part of the ski, and having multiple protruding keels that emerge from the horizon running surface of the ski proximal the ski's front end and gradually increase in protrusion with respect to the bottom running surface to a point of maximum protrusion at a point on the ski runner near to the steering spindle of the snowmobile is disclosed. The keel then gradually decreases in protrusion from its maximum protrusion to merge back into the bottom surface proximal the rear end of the ski.

1. A snowmobile steering ski assembly comprising:
 a frame for providing structural support to said ski and having attachment means for attachment of said frame to the steering mechanism of a snowmobile; and    an elongated ski fixedly attached to said frame and having a curved bottom running surface having a first radius of curvature and structured for gliding over a surface of snow, an upturned front end having a relatively short radius of curvature, a rear end distal from said front end, and three curved protruding keels having a second effective radii of curvature smaller than said first radius of curvature of said bottom running surface, said protruding keels gradually emerging from said bottom running surface proximal said front end and extending along a portion of said length of said ski runner and gradually merging into said bottom running surface proximal said rear end and wherein said keels are molded as a part of said bottom running surface.    
     
     
       2. The ski assembly of  claim 1 , wherein one of said keels is a central keel is located substantially along the longitudinal centerline of said ski and two of said keels are outrigger keels located near each longitudinal edge of said ski. 
     
     
       3. The ski assembly of  claim 1 , wherein said central keel has a maximum depth greater than the maximum depth of either of said outrigger keels. 
     
     
       4. The ski assembly of  claim 1 , wherein each outrigger keel has substantially the same size and shape. 
     
     
       5. The ski assembly of  claim 1 , wherein each keel is adapted to receive a wear bar. 
     
     
       6. The ski assembly of  claim 2 , wherein each outrigger keel is located along each longitudinal edge of said ski. 
     
     
       7. An improved snowmobile ski for attachment to the steering mechanism of a snowmobile comprising:
 Anan elongated member having a turned-up front end and an aft end, wherein said member has: 
 a bottom running surface extending from the turned up front end to the aft end;    an upper surface having means for attachment directly or indirectly to the steering mechanism of a snowmobile;    a central keel molded as a part of said member and protruding from the bottom running surface of said ski, said keel being substantially the same length as said running surface and having a generally curved shape along its lower edge with its maximum protrusion proximate that portion of the ski which is structured to be below the steering attachment of the snowmobile, said keel protrusion diminishing in both fore and aft directions from said keel's maximum protrusion; and    
 said central keel is located substantially along the center longitudinal axis of said bottom running surface and a pair of shallow-outrigger keels located near the longitudinal edges of said ski.  
 
     
     
       8. The snowmobile steering ski of  claim 7 , wherein said bottom running surface of said ski runner is curved upward from said front end to said rear end wherein said curve conforms substantially to an arc of a large radius circle. 
     
     
       9. The snowmobile steering ski of  claim 8 , wherein said central keel has an effective radius of curvature which is smaller than the radius of curvature of said ski runner. 
     
     
       10. The snowmobile steering ski assembly of  claim 1 , wherein said frame includes a grab handle structured for grasping by a user. 
     
     
       11. The snowmobile steering ski assembly of  claim 7 , wherein the protrusion of said central keel gradually increases relative to said bottom running surface of said ski runner from the front end along said length of said ski runner to a maximum protrusion at a point on said ski runner proximal said attachment means of said frame means to said snowmobile steering mechanism, whereupon the protrusion of said keel decreases along said length of said protruding central keel. 
     
     
       12. The snowmobile steering ski assembly of  claim 7 , wherein said elongated ski is plastic. 
     
     
       13. The improved snowmobile ski of  claim 7 , wherein said running surface of said ski on either side of said central keel is substantially flat along its length. 
     
     
       14. The improved snowmobile ski of  claim 7 , wherein said running surface of said ski on either side of said ski is a curved surface approximating a narrow section of a large radius cylindrical surface. 
     
     
       15. The improved snowmobile ski of  claim 7 , wherein said outrigger keels have a substantially straight lower surface. 
     
     
       16. The improved snowmobile ski of  claim 7 , wherein said outrigger keels have s a substantially curved lower surface. 
     
     
       17. A curved plastic snowmobile ski having a front-tip end and an aft with a bottom running surface therebetween, said bottom running surface being an elongated, rocker-shaped surface between said front tip end and said aft end and at least a pair of protruding keels molded into said rocker-shaped bottom surface, said keels having an elongated, rocker-shaped bottom surface curved to a radius of curvature significantly less than the radius of curvature for said bottom running surface.