| 摘要 |
671,749. Making paper bags. ANDERSSON, N. March 23, 1950 [March 31, 1949], No. 7346/50. Class 94(ii) In making paper bags provided with bellows side folds and a flat folded bottom, from a web which is guided and glued to form a flat tube with bellows side folds and then cut into blanks which are fed to a revolving drum and retained thereon while the bottoms are folded, the bottom-folding operation is prepared by moving the side walls of a flat tubular blank away from one another by two pairs of movable grasping fingers 9, 10, Fig. 2, mounted respectively on the revolving drum 6 and on an adjacent rotating member 7 co-operating with the drum, these grasping fingers being controlled to have a circling movement in a closed path circumscribing a surface extending radially as well as axially with respect to the revolving drum and the co-operating member 7. The bellows side folds are thus straightened out at the parts where the bottom fold is to be made, whereupon the grasping fingers release the blank, and folding means 11 mounted adjacent to the drum operate to complete the first folding of the bottom. During the continued rotation of the drum the bottom of the bag is completed by pasting and closing devices, and the finished bag is removed at 12 on to a conveyer or the like. Any known means are employed for forming a web into a flattened tube 2 which is severed transversely into bag lengths by cutting-rollers 3 and provided with longitudinal folding-lines by rollers 4, and then fed by rollers 5 to the drum 6. The drum 6 and the member 7 rotate in opposite directions, and the feeding-rollers 5 rotate at greater speed than the drum, feeding the blanks forwardly in succession so that each is retained under one of several catches 8 mounted on the periphery of the drum and thus rotated with the drum until the bottom fold is completed, whereupon the catches 8 are operated to release the finished bags, which drop on to the conveyer. Fig. 2 shows a portion of the drum 6, with the grasping fingers 9, 10 just moved into the bellows side folds preparatory to opening out the grasped portions of both sides of the bag. The fingers 9, located one at each side 13 and 14 of the drum 6, are each mounted on an arm 36 which is pivoted intermediate its ends on an arm 15, the arm 15, in turn, being pivoted on a lug 16 fixed on the end wall 13 or 14. The other end of the arm 15 carries a roller 17 which co-operates with a fixed cam bar 18, while at the same time a roller 19 mounted on the arm 36 engages a cam bar 20 on the adjacent side 39 of the machine frame, these actions combining to bring the finger 9 into its operative position. Similarly, the grasping finger 10, carried by an arm 37 which is pivoted on an arm 23 pivoted on the side of the rotary member 7, is controlled by roller and cambar combinations 26, 27 and 24, 25, the arm 37 being bifurcated at its pivoted end in order to straddle the shaft 40 supporting the member 7. |
