| 摘要 |
A stopper body of refractory material and cylindrical shape having a first end (10), a second end (14) and an intermediate zone (12) there between, with a bore (16) of circular cross section, extending from said first end (10) in an axial direction of the stopper body into said intermediate zone (12) towards the second end (14), wherein the said bore being provided with an enlarged cross section (at 16s) along at least part of said intermediate Zone (12). |
