| 摘要 |
1,000,993. Packaging-machines. HAMAC-HANSELLA A.G. Nov. 29, 1962 [Jan. 12, 1962], No. 45138/62. Heading B8C. A packaging-machine of the kind wherein a tube of wrapping material is pulled over a filling nozzle and is sealed transversely at intervals to enclose materials fed through the latter and wherein vertically reciprocating sealing jaws draw off the wrapping material, is characterized in that the closing of the jaws is effected by at least one compressed air piston through a transmission linkage, the cylinder, piston and linkage all moving with the jaws. As described, two cylinders 12 are mounted on cheeks 3 which are joined by a web 2 to a lifting column 1. Each piston 14 and piston-rod 15 are hollow and enclose a compression spring 16. At the commencement of a cycle each cylinder 12 is under pressure from air supplied to connection 13, each spring 16 is compressed and the column 1 is in its highest position. The jaws 6, 7 are then closed. The column begins to move downwards causing the tube 4 to be pulled downwards and then each cylinder is vented, but the jaws do not open since a pawl 21 (Fig. 5) acts on a roller 20, mounted on each piston-rod end 17 to prevent this. At the end of the downward stroke a photo-electric cell 35 senses a marking on the tube 4 and actuates a solenoid 30 which through a shaft 32 actuates the pawls 21 so that they release the rollers 20 thus causing the springs 16 to expand and the jaws to open. The upward movement of the column now begins and just before it has reached the top of its travel compressed air is again fed into the cylinders, thus forcing each piston and pistonrod back against the bias of springs 16, to close the jaws 6, 7. The pawls 21 reset and the cycle recommences. |
