Abstract: An apparatus for forming stacks from consecutively fed, flat workpieces, preferably bags, comprises a ram, which is movable up and down and serves to force the workpieces from a plane of conveyance onto a stacking plate or onto a stack formed on said stacking plate. The stacking plate is adapted to be lifted and to be lowered to an extent depending on the increasing height of the stack. In order to ensure that the ram will exert an approximately constant force on each workpiece as it is stacked, the stacking plate is adapted to be lowered against the action of a force exerted by a brake.

Abstract: A punching apparatus, preferably for punching intermittently moving webs of synthetic thermoplastics, comprises top and bottom tools, which are mounted in a machine frame and at least one of which is connected to a drive for moving said one tool up and down. The tools for making the punching cut consist of a knife plate or a knife ring and a backing plate or a backing ring and at the end of the punching cut strike against each other or almost contact each other.

Abstract: To make plastic carrying bags or sacks, sections are cut or are severed by hot wire welding from a gusseted tubular film by a formation of transverse seam welds and transverse severing cuts or by hot wire-welded transverse seam welds. At least in their bottom portion the sections are provided with corner seam welds, which are separately formed in the two folds and which diverge obliquely from the outer fold lines toward the top and/or bottom seam weld and terminate short of the inner fold line and merge into the latter. To prevent in the making of the carrying bags an elongation of the intermediate portion of the tubular film, the latter is initially formed with corner seam welds only in one fold of each of the two gussets before the transverse seam welds and transverse severing cuts or hot wire-welded transverse seam welds are formed. When said corner seam welds have cooled, congruent corner seam welds are formed in the respective other folds.

Abstract: Apparatus for conveying stacked flat articles provided with two locating holes each, preferably bags made of plastic, including a stacking conveyor having a pair of juxtaposed endless belts, which are trained around pulleys that are intermittently driven. The conveyor is provided with pairs of upstanding stacking pins, which are secured to respective carrying plates and spaced a variable distance apart. Alternate carrying plates carrying respective stacking pins are connected to respective ones of the belts. The belts are adapted to be moved forwardly and rearwardly relative to each other and to be interconnected by the pulleys in a predetermined relative position. The pulleys are angularly shiftable relative to each other to vary the spacing between the stacking pins.

Abstract: Apparatus for aligning a wicketer frame with an edge of a tubular or semitubular plastic web. The positions of the edges of the web are sensed and the wicketer frame is transversely displaced in response to and in dependence on the sensed deviation of the edges of the web from an initial position. The wicketer frame is provided with at least one transverse rail, which is supported on rollers or sliding surfaces of an underlying carrying frame to permit transverse movement of the wicketer frame relative to the web. The wicketer frame is connected by a beam to an end frame, which carries the downstream end of a stacking conveyor and is supported on a base frame. The end frame is longitudinally displaceable and is rotatable through a small angle relative to the base frame. A rack and pinion arrangement is provided for transversely moving the wicketer frame.

Abstract: In an apparatus for making plastics carrier bags from a web of tubular film of thermoplastic material, a feeding mechanism intermittently conveys the webs by one bag width and a severing mechanism cuts the web into half tubes along an undulating curve. A carriage displaceable in the machine frame transversely to the feeding direction of the web is reciprocated by a drive derived from a first rotating control cam through gearing. A cutting knife pivotable in the carriage about its longitudinal axis passes through the plane of the tube about an axis perpendicular thereto and is so controlled by an oscillating drive derived from a second rotating control cam that its edge is substantially tangential to the undulating curve at the cutting point. A detour assembly retards one of the half tubes to bring the bag side edge zones into phase and each half tube is formed into bags by a transverse sever-sealing device.

Abstract: Bag sections that pass through a machine are scanned as to their spatial positions within the machine. The measuring points have been arranged at distances corresponding to the stroke of the machine, so that it is possible to intervene in the operation of the machine when a deviation from a given nominal position occurs, before a stopper formation occurs. Each bag section that comes into the machine triggers a subsequent comparison of nominal and actual values in a manner such that the signals of defects that are generated by the lack of work pieces, are neutralized.