GB425800A - Improvements in and relating to electric arc welding - Google Patents

Abstract

425,800. Uniting by fusion. TRIGGS, W. W., 57, Lincoln's Inn Fields, London.- (Naamlooze Vennootschap Machinerieen - en Apparaten Fabrieken; 30, Croeselaan, Utrecht, Holland) May 10, 1934, No. 14127. [Class 83 (iv)] In automatic arc welding with completely covered electrodes, using a holder carrying two or more electrodes 5, 6, 7, Fig. 1, which are brought successively into the welding position by moving part of the holder, a feed apparatus is used which permits of a rapid return motion of the holder after the consumption of an electrode. In one arrangement the armature of the feed motor 2 which is normally fed at 12 to 24 volts is fed at 220 volts in the reverse direction. In a modification a rapidly set high speed reversing gear is incorporated in the transmission gear 3. Another modification employs a magnetic coupling in the gear 3 which may be disengaged to enable the holder to be raised quickly by hand. Uncoupling may also be effected by moving the rollers 12 which are for this purpose journalled in eccentric bushes. In a further modification the weight of the bar 4 and the electrode holder forms the driving force during feeding and the motor 2 locks the bar by a ratchet device against downward motion only. The rapid upward movement may be initiated automatically by means of a lever 14, Fig. 2, on the holder co-operating with a stop 15 on a bar 16 coupled to a reversing switch 17. The upward motion is stopped by providing a second stop 31 on the bar 16. The switch 17 may also control the traverse motor so that traversing is interrupted or reversed in direction during the return motion of the holder. Before reaching the top of its travel the rollers 20 on the locking pin 19 of the electrode holder engage the lever 22 and the pin is withdrawn so that the disc 25 will rotate due to the weight of the laterally arranged second electrode and the latter will move automatically into the welding position. In a modification idle return motion is eliminated. Every alternate electrode clamp is constructed so that it can be moved into and out of the electrode holder. As an electrode burns away the clamp is moved out of the holder by a small motor at twice the fusing speed and the holder is retracted at the fusing speed. When the electrode is consumed the next electrode is brought into position by simply rotating the holder.