Adjustable coupling device for a ski

An adjustable coupling device for coupling a ski boot to a ski, the coupling device having a longitudinal axis comprising:

• a toe binding and a toe binding guide;
• a heel binding and a heel binding guide;
• length adjustment means for altering the distance between the toe binding and the heel binding along the longitudinal axis of the coupling device to accommodate different size ski boots, said length adjustment means having a first drive element connected to said toe binding and a second drive element connected to said heel binding;
• means for synchronously moving said first and second drive elements;
• means for independently moving (a) said toe binding along said toe binding guide in a direction parallel to the longitudinal axis, and (b) said heel binding along said heel binding guide in a direction parallel to the longitudinal axis;
• means for setting said toe and heel bindings at a position corresponding to the length of the ski boot;
• and
• attachment means to attach said length adjustment means to a surface of the ski in the area of one of said bindings, the remainder of the coupling device being unattached to the ski so that the remainder of the coupling device can move freely in a direction perpendicular to the surface, whereby the distance between said toe binding and said heel binding remains substantially constant during bending of the ski.