| 摘要 |
<p>The invention concerns a device characterised in that: each of the elements (1) has a cross section substantially shaped like an upside-down U defining two substantially parallel lateral wings (1a 1b) assembled by a common transverse wing (1c); the elements (1) are arranged along at least two parallel superposed rows; the elements of one same row are juxtaposed so as to be non-contiguous leaving, over their whole length, an interstice (3); the elements (1) of two consecutive rows are offset such that the interstices (3) of the elements of one of the rows are arranged opposite the common transverse wings (1c) of the elements of the other row; the assembly of elements (1) is fixed to a support frame (2).</p> |
