Snowmobile ski having a self-steering keel arrangement

A snow vehicle destined to move over an underlying ground surface, comprising a main body, drive means carried by said main body and destined to set said snow vehicle in motion over the ground surface, a selectively controllable steering system carried by said main body comprising a steering pivot member pivotable about a steering axis, and an elongated snow ski pivotally attached to said steering axis of said steering system, said snow ski comprising:

• opposite top and bottom surfaces;
• opposite first and second sides;
• opposite front and rear ends, said ski defining a longitudinal axis extending between said front and rear ends;
• a transverse pivot joint member attached to said top surface and pivotally connected to said steering pivot member of said steering system, said transverse pivot joint member allowing pivotal displacement of said ski about a transversal axis extending between said first and second sides and extending transversely to and intersecting said longitudinal and steering axes;
• a pair of spaced-apart, elongated, longitudinally-oriented lateral keels integrally projecting from said bottom surface;
• an elongated, longitudinally-oriented central keel integrally projecting from said bottom surface, said central keel being longitudinally offset relative to said lateral keels and being located between said pair of lateral keels along said transversal axis;
• and
• a pair of elongate depressions positioned alone opposite outside edges of said bottom surface on either side of said central keel;
• wherein said ski is movable between a straight line position in which a ground plane that intersects a lowermost surface of said lateral and central keels is defined, with said steering axis forming an acute angle relative to said ground plane, and a turn-carving position in which said ski is pivoted about its steering, longitudinal and transversal axes relative to said straight line position and is inclined laterally so that only said central keel and a single one of said pair of lateral keels intersect said ground plane and the other one of said lateral keels is raised above said ground plane, said depressions defining a ground clearance in the vicinity of said central keel allowing said ski bottom surface to remain spaced from said ground plane in said turn-carving position of said ski.

An elongated snow ski for use on a snow vehicle and destined to glide on and carve a ground surface, said ski being able to take a straight-moving position and a turn-carving position, said ski comprising:

• opposite front and rear ends;
• a ski sole having two lateral edges extending between said front and rear ends;
• a longitudinal axis extending between said front and rear ends, and a transverse axis extending transversely across said lateral edges, perpendicularly to said longitudinal axis;
• first, second and third elongated keels fixedly projecting from said ski sole, said first and second keels being in facing register with each other, and off-centered on said ski sole with respect to said transverse axis, said third keel being intermediate to said first and second keels with respect to said transversal axis, and said third keel being substantially longitudinally offset relative to said first and second keels with reference to said longitudinal axis;
• and
• a pair of elongate depressions positioned along opposite outside edges of said ski sole on either side of said third keel;
• wherein said first, second and third keels are destined to carve the ground surface when said ski is in said straight-moving position, and wherein, when said ski is driven and is set in said turn-carving position, only a selected one of said first and second keels and said third keel are destined to carve the ground surface in order for said ski to exhibit a self-steering behavior.