| 摘要 |
<p>A sheet welding machine comprising a wedge-shaped heater adapted to be put in heat-transmission contact with the edges of upper and lower sheets for thermally melting the edge, and a pair of upper and lower pressure rollers disposed in the proximity of the converging portion of the heater, wherein two sheets are continuously welded along their edges by the heater and pressure rollers. The sheet welding machine has a compressed air delivery pipe connected to a compressed air source, the delivery pipe projecting from the converging portion at the middle of the heater in the direction of travel of sheets. The front end of the delivery pipe extends through the nip between the pressure rollers and delivers compressed air forwardly of the direction of travel of sheets. The edges of the overlapping sheets are formed with two rows of continuous weld bands and are welded together. At the same time, a channel filled with compressed air is formed between the right and left weld bands. According to this welding machine, since welding can be accomplished while detecting leakage of air from the channel during welding, it is possible to specify defective welds and make repairs or the like immediately after occurrence of such defective welds.</p> |
