GB873726A - Apparatus for fabricating flat and bottom-folding bags - Google Patents

Abstract

873,726. Bag-making machines. HESSER, MASCHINENFABRIK A.G., FR. Sept. 3, 1959 [Sept. 15, 1958], No. 30108/59. Class 94(2). A blank 1a is cut off a web of material of a length corresponding to the required bag width and is fed by belts 8, 9 to a folding wheel 11 which is rotatable stepwise between two fixed guide cheeks 18 and includes at least one folding segment 12 whereby a bag blank fed to the apparatus is engaged along a medial line by an edge of the folding segment, drawn between the guide cheeks and thereby folded, and the thus-folded blank is withdrawn by conveyer belts 22. Each segment has a clip 15 which holds the blank in position on the segment as the folding wheel 11 rotates, the clips being movably applied against the folding edges of the segments by spring tension and lifted for the introduction and withdrawal of the blanks by the action of a cam disc 17 through arms 16 associated with the segments. The belts 8 are raised, by means not shown, to release the blank and it is then drawn between the guide cheeks 18 which are curved outwards at the entrance to the space between them. After 90 degrees rotation the blank is folded and the movement ceases while the folded blank is heat sealed by sealing jaws 30, a fresh blank being fed in at the same time. The folding wheel 11 then rotates through another 90 degrees and brings the sealed longitudinal seam of the blank between pairs of vertical rollers 20, 21 which open and close under spring pressure, drawing the blank from the folding segment. Belts 22 convey the folded blank to sealing jaws 31 which heat-seal a second seam and form the blank into a bag. In a modification the jaws 30 are arranged parallel to the jaws 31 a bag-width apart. The apparatus may be adapted, Fig. 4, to make bottom-folding bags by the addition of folding plates 23 at both sides of each folding segment 12 which are shifted beyond the folding edges and make a double fold, as shown in Fig. 7. The shifting may be done by a cam 25 through arms 26 rotatably mounted on the hub of the folding wheel 11, and connected to toothed segments 27 in mesh with toothed segments 28 attached to the folding plates 23. Alternatively a parallelogram linkage system could be used. The guide cheeks 18 are movable for adaptation to bag materials of different stiffness and thickness and the complete folding assembly is vertically adjustable, in relation to the belt 22 and rollers 20, 21, to allow for the production of different sizes of bag.