| 摘要 |
The preferred embodiment is to replace the spring 8 with two springs 24 hooked onto the screen 9 either at one point 25 or at two different points 26. The parts 5, 6 and 7 are replaced by the parts 27 welded to the raised part of the cradle. The swing of the sides is limited by the parts 28 welded to the tubes 3 and 4 and abutting against the parts 27. The hooks 13 and 14 which enable the sides to be held open are fixed to the upper rim of the cradle. <IMAGE>
|
