Patent GB-702648-A (GB)
Title: Improvements in and relating to strip welding machines
Inventor: WIETZEL KARL FREDERICK
IPC: B23K5/06
Filed: 1952-06-03
Abstract: 702,648. Welding by fusion. ARMCO INTERNATIONAL CORPORATION. June 3, 1952, No. 14039/52. Class 83 (4) In a machine for welding metal sheets end to end to form a strip two torches are translated simultaneously in opposite direction from a middle position over the welding path and overlap on a middle portion which is operated upon by both torches. A pair of torches 41, 57, Fig. 1, above and below the strip 25 are moved over a central portion of the strip to the left while another pair 41a and 57a is moved over the same central portion to the right, by a screw feed rod 28 having left-hand and right-hand threads. The upper torches 41, 41a are supported on slides 40, Fig. 5, movable over guide rails 29, 30 and having threaded attachments on arms 34 engaged by the screw threaded feed rod 28, a longitudinally slidable sleeve (not shown) being provided in the slide 40 for the right-hand torch 41a to provide lost motion so that the torch does not move until the left-hand torch 41 has completed welding the central portion of the strip. The lower torches 57, 57a are mounted on slides 60 moving over guides 55, 56 and coupled to move simultaneously with the upper slides 40 through push rods 52 and arms 53. The ieft-hand torches 41, 57 are rigidly mounted and the right-hand torches 41a, 57a are pivotally mounted and yieldingly held in welding position by springs 69. When the torches are in overlapping position projecting rods 60a, 62, Fig. 4, on the left-hand slides 41, 60 engage projecting arms 67, 70 on the right-hand torches and hold them in a tilted position clear of the work until the left-hand torches have welded the central overlapping portion. Automatic switches, valves &c., 83, 85 adjustably mounted on a rod 73 above the machine and adapted to be engaged by the slides 40, 41 control the sequential movement of the machine, switching on the igniters 72 for the left-hand torches, and turning gas supply on and off for each torch. The right-hand torches are ignited by the left-hand torches on moving into position. The sheets 25 to be welded are held in abutting relation on magnetic tables 10, 11, Fig. 5, energized by coils 16. Central portions 17 of the tables are non-magnetic but clamping plates 19, 20 yieldingly supported above the sheets 25 on springs 23, Fig. 1, form magnetic circuits to clamp the sheets. In a modified machine (not shown) the lower slides are moved independently of the upper slides by a second threaded feed rod mounted below the machine. All the torches are rigidly fixed to the slides but the right-hand slides have lost motion and are yieldingly held by springs to abut the left-hand slides when both slides are near the centre of the machine. In operation as the feed rods rotate, the lefthand slides are fed to the left with their torches in operation and the right-hand slides also initially move to the left with the left-hand slides under action of the springs, but with the torches turned off. When the lost motion has been taken up the right-hand slides are positively fed to the right and the torches set in operation so that the central portions of the joint is welded twice.