1. Field of the Invention
The present invention relates to a lateral guidance and support apparatus of a ski shoe or boot which is attached at its front end to a cross-country ski and whose heel is free to be displaced at least vertically. In addition, the present invention relates to a cross-country ski which assures such lateral guidance, and to a ski boot which is adapted to engage such a lateral guidance and support apparatus.
2. Description of Background Materials
Various apparatus are known which laterally guide and retain a cross-country ski shoe or boot on a ski. Some of these apparatus comprise a longitudinal guidance rib which is adapted to engage a groove of the same configuration provided in the sole of the shoe. This arrangement assures the lateral guidance and retention of the boot during the gait of the foot, i.e., when the shoe or boot is flattened on the ski. In addition, this longitudinally extending guidance or centering rib can extend the length of the plantar support zone of the foot. Such a guidance apparatus is described, for example, in French Pat. No. 84 08 714 in the name of Applicant.
As described in this French Patent, the guidance rib comprises a projection which extends laterally from the rib. The projection is positioned directly beneath the plantar arch of the foot when the shoe is flattened on the ski. As a result, this projection does not contribute to the lateral guidance or retention of the shoe during the greater portion of the gait, which is disadvantageous, even though it laterally maintains the shoe on the ski when the shoe is flattened on the ski.
Thus, there is a need for a lateral guidance apparatus which laterally retains and guides the boot on the ski during a greater portion of the gait of the skier.