GB142090A - Improved process of and apparatus for electrical welding - Google Patents

Abstract

142,090. Wilson Welder & Metals Co., (Assignees of Churchward, A.). April 22, 1919, [Convention date]. Heating by electricity. - Apparatus for are or other welding comprises a resistance in series with the weld, controlled by a circuit in shunt with the weld; by this means the current may be automatically increased as the arc is lengthened. As shown, a pile resistance 24, in series with the arc welding electrode 26, is regulated by the differential action of two solenoids 23, 27 acting through a spring-controlled lever 29, one of the solenoids 23 being in series with the arc and resistance 24, and the other 27 in parallel with the arc. When the arc is lengthened by withdrawing the electrode from the rail 6, the shunt solenoid 27 operates the lever 29 to reduce the resistance 24, and thereby increase the current. At starting, when the electrode is in contact with the rail, the solenoid 27 is short-circuited, and the series solenoid 23 causes the resistance 24 to be increased. The Specification as open to inspection under Sect. 91 (3) (a) comprises also apparatus for maintaining a constant pressure consisting of a dynamotor with one field winding, Fig. (Cancelled) in series with the motor armature 11, and with a variable starting resistance 9, and another field winding 13 in long shunt. A high-resistance solenoid 14, in parallel with the motor armature 11, controls the starting resistance 9 and also a pile resistance 19 in series with the dynamo armature 20 and the welding circuit. The last segment 15 of the starter is made long enough to allow considerable movement of the solenoid core without breaking contact between the switcharm 8 and the segment. As the motor speeds up, the pressure across the armature causes the solenoid 14 to cut out the resistance 9. At normal pressure the resistance is maintained at a minimum by means of a spring 18 controlling a lever 17. If the pressure of supply from the main 3 is increased, the solenoid 14 operates the lever 17 through a non-magnetic extension on the solenoid core, so as to increase the resistance 19 and thereby maintain a constant pressure in the welding circuit. The apparatus may be mounted on a railway hand car. This subject-matter does not appear in the Specification as accepted.