| 摘要 |
<p>The door has hollow seams and/or reinforcement ribs (42) and the distances (a,b,c,d) between the two are varied from top to the bottom and depends on the diameter of the winding shaft (30) and has value between 12 to 15 times the diameter of the winding shaft. The distance lying between the bottom and the upper reinforcing ribs has a value between 4 to 15 times the diameter of the winding shaft.</p> |
