GB417245A - Improvements in and relating to welding machines - Google Patents

Abstract

417,245. Electric welding. INTERNATIONAL GENERAL ELECTRIC CO., Inc., 120, Broadway, New York, U.S.A.- (Assignees of Allgemeine Elektricitõts-Ges. ; 2, Friedrich Karl-Ufer, Berlin.) Dec. 28, 1932, No. 36699. Void [Abridged as open to inspection under Sect. 91 of the Acts, June 29, 1933]. [Class 83 (iv).] A spot welding machine provided with two or more electrodes is held against the work by an electromagnet to facilitate welding on vertical or overhead surfaces. A double electrode c,d mounted in a casing is pressed against the work by a screw g engaging the core b of an electromagnet. The electrodes may be rigidly mounted in the casing or, as shown, may be operated through springs e, a stop i being provided to prevent the springs from falling out. The screw may be operated direct or through a lever or the pressure may be exerted by a motor. The welding current and current for energizing the electromagnet may be automatically switched off, the welding current being preferably switched off first, so that the pressure of the electrodes is maintained for a short period thereafter. If hand switches are used the switch for the electromagnet may be inserted in the primary circuit of the transformer. The limbs of the electromagnet core may operate on both sides of the work. The core may be subdivided so as to provide an air gap to weaken the flux therein when the apparatus is placed in position.