| 摘要 |
<p>The bar is characterised in that its poking nose comprises in its wall, which is perpendicular to the central longitudinal plane of the bar and situated on the distant side of the end, a central part set back towards the interior of the nose, which forms a cavity (5) which opens in the direction of the axis of the bar, at least one lateral wall delimiting the cavity (5) has an orifice (10) for air distribution and the surface (9) delimiting the cavity (5) in the downstream direction has an opening, the transverse cross-section of which is a number of times greater than the transverse cross-section of the lateral orifice (10). <IMAGE></p> |
