GB267544A - Improvements in or relating to electric spot welding machines - Google Patents

Abstract

267,544. International General Electric Co., Inc., (Assignees of Allgemeine Elektricitõts-Ges.). March 13, 1926, [Convention date]. Transformers.-In an electric spot welding machine, the electrode arms 4, 6 forming the secondary winding of the transformer comprise a number of laterally-spaced bars between which disc coils 2 forming the primary winding are disposed. A cooling worm 5 is placed between the lower bars 4 which are secured to the frame 15 of the machine and to the welding table by bolts 14 and are connected by flexible cables 7 to the upper bars 6. The latter are clamped by a screw 12 to a block 10 and are pivoted at 9, the other end thereof being caused to grip the electrode 21 by means of a. bolt 35. A switch 20 adapted to close the primary circuit after the electrodes have been brought into contact with the work is provided. The switch 20 is normally held open by an insulated button 27 carried by a rod 17 connected to the lever 23 carrying the operating pedal 33. The rod 17 is connected to the upper electrode arm by a pin and slot arrangement 26 affording lost, motion. Initial movement of the pedal causes the upper electrode to be brought into contact with the. work through the medium of rods 18 and springs 24, Fig. 3. Further movement of the pedal to bring pressure on to the work necessitates movement between the rod 17 and the upper electrode arm thus retracting the button 27 and allowing the switch to close under the action of a closing spring.