| 摘要 |
<p>1,094,830. Seaming non-metallic sheet material. WELDOTRON CORPORATION. July 28, 1966 [Sept. 1, 1965], No. 34005/66. Heading B5K. Two superposed webs 50A, 52A of heat shrinkable thermoplastic material are sealed together along a predetermined line by clamping the webs together adjacent the line, heating the clamped together portions along the line to a temperature to shrink, but not melt, these portions into intimate contact with each other, and heating the shrunk portions at a higher temperature to melt a gap therein along the line and to join together the superposed edges of the webs bounding the gap. Apparatus similar to that disclosed in Specification 1,075,869 comprises heating assemblies 74A, 76A to shrink the clamped portions of the webs 50A, 52A and 74B, 76B to effect cutting and sealing of these portions. The webs 50A, 52A are clamped between two pairs of conveyer belts 38A, 40A, the other pair, not shown. The assemblies 74A, 76A, 74B, 76B are identical and the assembly 74A comprises an element 92A which passes around guide rollers 106A, 108A mounted to fixed insulator brackets 80A, 82A. A tension spring 102A holds the element 92A taut to compensate for any thermal expansion thereof. Spring urged pressure bars 150A, 152A, 150B, 152B bias the runs of the belts 38A, 40A together. The webs 50A, 52A may be sealed together along two laterally spaced predetermined lines to form a tube.</p> |
