| 摘要 |
981,156. Making containers or liner bags. PNEUMATIC SCALE CORPORATION. April 17, 1963, No.15087/63. Heading B5D. A machine for making rectangular containers or liner bags comprises forming blocks 10, mounted on a central rotatable shaft 14, and about each block, at a first station of operation, a sheet of thermoplastics material is folded to a U-shape by plates 45 and 46, the projecting flaps 48 and 51 of the blank being folded against a face of the block by folding plates 70 and 72 and sealed to form a side seam 55 by means of a heat-sealing bar 136. Each folding plate is slidably mounted on a retaining plate 94 which is connected to a rocker shaft, the retaining plates engaging opposed upper edges of the block and the folding plates continuing across and parallel to the top of the block to fold the flaps 48 and 51 thereonto. The sealing bar has ridges which co-operate with a heatresistant rubber-like insert in the block to perform the sealing operation. At a second station of operation the tube has its opposed end wall portions folded inwardly in overlapping relationship about an end of the block by blades and a heat-sealing means seals the bottom closure along spaced lines 264 and 266. The block moves to a third station where means are provided for sealing the closure in spaced narrow pairs of lines 302 and 304 at right-angles to the first lines. At this station an outer sheet may be wrapped around the block and liner bag with its overlapping marginal portions being adhesively sealed together at an edge of the block and its extending end portions folded up and adhered together to form an end closure. The machine is driven by an electric motor having a solenoid-operated switch 366 in its supply circuit and which is provided with a safety circuit arranged to energize the solenoid when malfunction of the machine occurs, a cam operated switch 350 being arranged to prevent energization of the solenoid when the heat sealing bar is in engagement with the block. |
