| 摘要 |
<p>Process for mfr. of lattice beams by cutting saw teeth in the web of a suitable profile to form two separate complementary pieces (I), and reuniting the summits of the teeth. (I) are moved in a continuous translational movement at a constant speed greater than the speed of welding, while the welding torch (II) is displaced in an alternating movement so that when (II) moves in the same direction as (I) is speed is the constant speed minus the speed required for welding, and when (II) moves in the opposite direction to (I) to return to its starting posn. its speed is much greater. Electric supply to (II) is made by two feelers only when a metal part is below (II).</p> |
