摘要 |
<p>The tree has movable transversal units (12, 14, 16), and a longitudinal central column (10) comprising a profile conjugated to that of a shoe in a longitudinal median plane. The column has thickness in the order of 15 millimeters. The transversal units have recesses (12-2, 14-2, 16-2) along transversal section of the shoe, where the recesses cooperate with corresponding recesses (12-1, 14-1, 16-1) of the column.</p> |