| 摘要 |
A packing machine for making filled and sealed bags from superposed wrapper sheets, has a pair of cooperating sealing rollers for providing longitudinal seams on the superposed wrapper sheets passed therebetween; a mechanism for rotating unidirectionally the sealing rollers in first and second consecutive steps for providing the longitudinal seams in two consecutive length portions, each corresponding to one-half of the predetermined length; a pair of cooperating sealing shoes movable towards and away from one another for assuming, respectively, a sealing position to provide a transverse seam on the superposed wrapper sheets and an idling position; and a mechanism for moving the sealing shoes, while in the sealing position, codirectionally with the travelling direction of the wrapper sheets during a period in which one of the two steps is performed and for moving the sealing shoes, while in the idling position, against the travelling direction during a period in which the other of the two steps is performed.
|
