| 摘要 |
<p>787,126. Electric arc welding. KRAFTANLAGEN AKT.-GES. March 12, 1954 [March 14. 1953; March 16, 1953; March 18, 1953; Nov. 18, 1953], No. 7250/54. Class 39(3) Arc welding apparatus for use with electrodes laid longitudinally between or on the edges of a joint comprises one or more pressure members of non-magnetizable material each secured to means for producing an auxiliary magnetic field for controlling the weld, the pressure members being adapted to clamp the electrode against the work piece or pieces. As shown in Fig. 2, a pressure member consists of a block 3 releasably secured between the pole pieces of a core magnetizable by a coil 5, the block pressing an electrode 2 on to the work piece 1. A groove for locating the electrode in the block may be rectangular in section and recesses 28 may be formed on either side of the groove 26, Fig. 12, for containing the slag formed during welding. Fig. 9 shows how pole pieces 17 producing the controlling field are disposed for ensuring that the fused material does not flow downwardly from the upper edge of a horizontal seam in a vertical wall 1. Fig. 1 shows how a number of pressure member assemblies are joined together for producing a circular weld in a pipe 1, springs 7, 8 maintaining the assemblies in position. In Figs. 4, 4a, current supply and cut-off means comprises a copper strip 13 which may slide along a pin 15 secured on insulation 16, the strip pressing against a heavy copper cap 11 which may have a coating of silver or silver graphite to prevent contact welding and which is secured to the stripped end of the electrode 2. As the electrode expands with heating, the strip 13 is able to move along the pin 15. When the electrode 2 has been used up its end remnant drops under the weight of the cap 11 and current supply from a cable 12 is cut off. When alternating current is used with the apparatus power factor correction may be applied. Ceramic, hard carbon or a ceramic graphite compound are specified as materials for the blocks 3.</p> |
