| 摘要 |
A quarter fold folding device is described, having a quarter fold blade suspended by two opposite ends from two pivots, which are free to rotate with respect to the blade and are securely fastened to two connecting rods at one of their ends. The connecting rods are, at their opposite ends, rotationally driven in opposite directions, respectively, by means of two horizontal shafts rotating about their longitudinal axis. The rotating shafts are simultaneously rotationally driven in opposite directions respectively about two horizontal and parallel central axes, so that when the two rotating shafts perform a complete revolution about the parallel central axes, the two opposite ends of the folding blade driven by the connecting rods describe two parallel vertical segments of a straight line between a bottom position and a top position of the quarter fold blade. The quarter fold blade in the bottom position engages a signature between two folding cylinders, so as to form a longitudinal fold in the signature. The quarter fold folding device also includes a system for balancing the dynamic forces generated by the moving quarter fold blade. This balancing system also includes two counter weights, rotationally mounted respectively on the shafts for rotationally driving the two connecting rods, so that the fly weights follow the opposing rotational movements of the connecting rods. |
