| 摘要 |
746,140. Photo-electric control of web feed. TRANSPARENT-WRAP MACHINE CORPORATION. April 7, 1954 [April 11, 1953; April 11, 1953; April 11, 1953; April 11, 1953], Class 40 (3). [Also in Group XVII] In a packaging machine (see Group XVII) a web, provided with a series of marks S spaced longitudinally by a distance corresponding to the required length of package, is folded around a filling-nozzle 41 to form a tube which is drawn downwardly by reciprocating jaws C which are closed and opened in synchronism with their vertical movements and operate to seal the tube transversely between successive increments of material delivered through the nozzle. The stroke of the jaws exceeds the length of the package to be produced, and the jaws are opened before the end of their downstroke by mechanism controlled by a photoelectric cell E which observes the marks S on the web. |
