| 摘要 |
The block has an upper plate (3) extending, parallel with respect to a lower side (11 1), in a plane projecting to an extension plane. The plate is bordered according to a traffic stream of a vehicle by upstream and downstream rampants (5, 6) extending up to the extension plane and delimited by leading and trailing edges. A heel rest (20) projects, from the lower side and leading edge, on a limited length based on the stream. |
