摘要 |
To match the speed of a folding flap cylinder (12) folding sheets cut from a web in half to a slower speed of a gripper chain delivery system (17, 18), a transfer cylinder (15) with grippers (16) is provided which operates at a circumferentially non-uniform speed (FIG. 3, curve 30), in which the speed of the transfer cylinder (15), when receiving a sheet from the folding flap cylinder (12), is essentially synchronous therewith, and then decelerates to be essentially synchronous with the speed of the gripper chain delivery system (17), for subsequent acceleration to the speed of the folding flap cylinder. The circumferentially non-uniform speed is obtained by driving the transfer cylinder (15) through a worm transmission in which the worm has a non-uniform pitch or non-uniform angle of inclination of the worm groove or the respective worm lands defining the groove.
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