| 摘要 |
<p>The protective helmet has a hemispherical cap (1) made in strong material isolated from the head of the user. The outer surface of the cap has small hollows (3) round its main axis of symmetry (I-I) in the sides of which there are ventilation holes (4). Each hollow is delimited by an upper edge, near the axis of symmetry, two lateral edges and a lower edge opposite the upper edge. The ventilation holes are in the upper edge. The hollows are separated from each other and allow water to run off the helmet.</p> |
