| 摘要 |
<p>1,075,869. Seaming non-metallic sheet material. WELDOTRON CORPORATION. Dec. 1, 1964 [Dec. 5, 1963], No. 48806/64. Heading B5K. Apparatus for radiant heat melting and sealing of superposed layers 50, 52 of a heat sealable material comprises a pair of conveyer bands 46, 48 to clamp the layers 50, 52 therebetween with a free portion extending therefrom, and radiant heating means 70, 72 disposed to simultaneously heat both faces of said free portion of the clamped layers 50, 52 to form a seal. In one embodiment, Figs. 1 and 2, the conveying means comprises flexible bands 38, 40, 42, 44, 46, 48, 49, 51 of high strength, resistance to heat and thermal conductivity, e.g. of stainless steel, extending around aligned pairs of rollers of two sets 6, 8 mounted on shafts 26, 28 and 34, 36, respectively. The rollers situated above the layers 50, 52 are all driven counterclockwise of Fig. 1 and those below clockwise at substantially the same rotational speed. The shaft 26 is driven by a variable speed motor 60, preferably an electric motor, and the shaft 28 is driven therefrom through gears 56, 58. The rollers of the set 8 are driven by frictional contact with the bands 38, 40, 42, 44, 46, 48, 49, 51 driven by the rollers of the set 6. Alternatively, the shafts 34, 36 may be driven by a motor and intermeshed gears or the roller set 8 may be driven from the set 6 through a sprocket and chain arrangement. Four radiant heating assemblies 70, 72, 74, 76 are provided. The assembly 74 comprises a thin, metal radiant heating element 92 extending between supports 80, 82 and connected to conductors 88, 90. The element 92 extends around guide rollers 106, 108 and is held taut during heating thereof by maintaining the conductor 90 stationary and spring biasing the conductor 88 away from the support 80 by a tension spring 102. Similarly assemblies 70, 72, 76 comprise heating elements 118, 122, 114 respectively. A stationary support 150 is provided beneath the upper run of each lower conveyer band and a movable pressure bar 152 pressed by compression springs 156 is situated above the lower run of each upper conveyer band. In use, the elements 92, 114, 118, 122 are energized and then the motor 60 is energized to drive the roller sets 6, 8 and the bands. The layers 50, 52, e.g. of oriented polypropylene, are fed from the left of Fig. 1 into the apparatus and are cut and sealed during passage therethrough to form beads 130, 132, 134, 136. In a modification (not shown), additional sets of rollers, bands and heating elements are arranged on the right hand side of the apparatus of Fig. 2 to form one or more additional continuous tubes. In another modification, Fig. 3 (not shown), the bands 38, 40, 49, 51 are omitted and in a further modification, Fig. 4 (also not shown), only the bands 46, 48 and the heating elements 118, 122 are provided.</p> |
