Abstract: An automatic screwing device, especially a hand screwdriver, consisting of a screwdriver and a collet to hold a secured protruding screw. The screwdriver is coupled to an actuating device so that it can rotate and move forward in relation to the collet. The actuating device has a first threaded element which can be driven rotationally and connected to the screwdriver and at least a second threaded element which is connected to the collet and interacts with the first threaded element. By providing two different thread pitches on the first and/or second element the screwdriver can advance at two different speeds while rotational speed of the first element remains the same.

Abstract: A driving method and system for controlling the operating characteristics of a tubular-bag machine, in which a tubular bag is closed off at the bottom end so as to be fillable with packing material through a fill pipe. An intermittently moved thin foil tube is for this purpose guided vertically between transversely arranged, heated sealing jaws, the opening and closing of which being camcontrolled. The foil movement is adjusted to the opening and closing movement. The drive for effecting the foil movement and the drive for effecting the sealing, separating and welding device are driven by separate motors controlled independently from one another, and are adjusted to one another such that each angular-speed stage can be adjusted independently from the preceding or following stage to the demands of the work cycle at any time during the work cycle. The magnitude of the angular speed can be adjusted as well.

Abstract: A packaging machine for manufacturing filling and closing of bags. A foil tube (4) is pulled off continuously by means of unwinding belts (13) on a packaging machine contracted as a tubular bag-forming machine. Cross sealing seams are created by means of continuously moving cross sealing jaws. The cross sealing jaws are maintained in a horizontal position during their entire movement by being guided in guide grooves. The guide curves have straight curve pieces in the area of a sealing zone, which curve pieces extend parallel with respect to the unwinding direction of the foil tube (4). The packaging machine permits a high operating speed, since the cross sealing occurs simultaneously with the unwinding movement and the cross sealing jaws, are guided exactly in an optimum position with respect to the foil tube. (4). The machine can be operated such that the unwinding speed for the thin sheet material is only a little slower than the speed of the goods to be packaged at the end of the fill pipe.