| 摘要 |
An apparatus for controlling machines for making bags or sacks severed by welding from continuous tubular or semitubular films of synthetic thermoplastics has at least one pair of pinch rollers for feeding the continuous film. The pinch rollers are driven via a transmission by a first motor. A pair of welding jaws provides the continuous film with seam welds, transverse seam welds or severed transverse seam welds. A second motor actuates the welding jaws via a drive mechanism. A central processing unit controls the motors in such a manner that the motor for the pair of welding jaws is energized at a time when the motor for driving the pair of pinch rollers is still driving the pinch rollers, and after a standstill phase of the motor for driving the pair of pinch rollers the latter motor is energized even before the motor for driving the pair of welding jaws has stopped.
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