| 摘要 |
The nosing has a covering section (3) and a base section (2) linked by a linking unit (4). The section (3) has a longitudinal fork (10) receiving a longitudinal vertical wing (8) of the section (2). Notches (12) of one branch of the fork co-operate with notches (9) at one side of the wing. A longitudinal tangential contact between convex and smooth surfaces (14, 13) is envisaged between the other side and another branch. |
