Mechanical traction for a cross-country ski

#This invention relates to mechanical traction enhancements for snow skis.

#In the classic style of cross-country skiing, as opposed to the skating style, traction is conventionally effected through the use of wax. During gliding the ski slips on a microscopic film of water created by friction between the ski and snow. When the ski stops, ice crystals in the snow embed in the wax, thereby creating traction. The type of wax used varies with snow temperature and texture. The wax wears off and must be re-applied. Improper waxing can inhibit gliding, give insufficient traction, or both. Changes in snow conditions can make a particular wax ineffective. Thus, ski wax cannot yield optimal results in all snow conditions at all times.

#Another common means of giving traction to a ski is the practice of molding or inscribing a fish-scale pattern of scales in the base of the ski. The scales are low-inclined planes which present perpendicular biting surfaces towards the rear of the ski. These waxless skis require less learning-time, skill and effort to use, but give less satisfactory glide and traction in comparison to waxed skis. Both traction types, wax and fish-scale, will fail on steeper grades and the skier then resorts to climbing with skis in a herring bone pattern; side-stepping with skis transverse to the grade; or to removal of the skis at the bottom of the slope, walking up, and remounting the skis at the top.

#In drawings which illustrate by way of example only embodiments of the invention:

#FIG. 1 is a perspective view of a portion of a ski for traveling on snow-covered ground, showing a traction device according to a first embodiment of the invention in a disengaged position;

#FIG. 2 is a perspective view of the portion of the ski shown in FIG. 1, showing the traction device in an engaged position;

#A ski for traveling on snow-covered ground, the ski having a longitudinal body defining a sole for contacting the snow-covered ground, comprises: (a) platform means for sliding longitudinally relative to the body; and (b) snow-gripping means for extending in a direction perpendicular to the sole in response to the platform means sliding longitudinally relative to the body.

#Referring to FIGS. 1 and 2, a portion of the ski according to a first embodiment of the invention is shown generally at 1. The ski 1 is useable for traveling on snow-covered ground (not shown). The ski 1 includes a mechanical traction device 21 according to the first embodiment of the invention.

#The ski 1 includes a rail, such as the U-shaped rail 2 shown in FIGS. 1 and 2 attached to an upper surface of the longitudinal main part or ski body 22 of the ski 1. A platform, such as the C-shaped sliding platform 3 shown in FIGS. 1 and 2, is shown coupled to the ski 1 via the rail 2. In the first embodiment, the sliding platform 3 is slidably coupled to the rail 2, thereby allowing the platform 3 to slide longitudinally along the ski body 22. FIG. 1 shows the sliding platform 3 in its longitudinally forward position toward a front section (not shown) of the ski 1, and FIG. 2 shows the sliding platform 3 in its longitudinally rearward position toward a rear section (not shown) of the ski 1.