DISPOSITIVO PER IL TAGLIO E LA SAL DATURA DI UNA GUAINA DI MATERIA TER MOPLASTICA PARTICOLARMENTE PER LA FABBRICAZIONE DEI SACCHI

摘要

1460052 Seaming non-metallic sheet material; cutting apparatus G LAGAIN 26 March 1974 [26 March 1973] 13449/74 Headings B5K and B4B Apparatus for longitudinally cutting and welding a continuously-fed tube 1 of thermoplastic material so as to divide the tube into a plurality of tubes of lesser width, comprises at least one heatable blade 17 having a tapering portion 16 to extend into a groove 3 in the surface 4 of a table 2 over which the tube 1 is arranged to be moved in a direction following the longitudinal axis of the blade 17, the blade 17 and the table 2 being relatively movable along the longitudinal axis of the blade 17 so as to alter the length of the blade in contact with the tube. In one embodiment, Figs. 1 and 2, the blade 17 and the table 2 are curved. The table 2 is mounted between end-pieces 5, 5a secured to a shaft 6 rotatable in bearings 7, 7a supported on rams 10, 10a so as to be vertically movable in slides. The table 2 is swingable in the directions F 1 by rotation of the shaft 6 by a reduction motor 14. Switches 15, 15a limit the movement of the table 2 by stopping the motor. The blade 17 is heated by electrical resistances 18 and is provided with insulating members 19, 19a to which clevises 21, 21a are hinged about shafts 20, 20a. Into the clevises are screwed ends 22, 22a of rods 23, 23a rotatable in a bar 24 slidable on rods 25, 25a. By adjusting the rods 23, 23a the height or inclination of the blade 17 can be altered to allow the penetration of the portion 16 into the groove 3. A roller 28 holds the tube 1 away from the blade 17 before it passes over the table 2. A plurality of blades 17 may be suspended on the rods 25, 25a. In another embodiment, Figs. 4 and 5, a straight blade 29 has a tapered portion 30 extending into a groove 31 in a flat table 30 movable in a straight line following the axis of the blade 29 so as to adjust the amount A of the tube 1 in contact with the blade 29. Rollers 34, 35 hold the tube 1 away from the blade 29. In a modification, the tube is fixed and the blade is movable. The blade may be provided with means for heating its leading and trailing edges to different temperatures.