GB680531A - Improvements in and relating to apparatus for electric arc stud welding - Google Patents

Abstract

680,531. Welding by pressure. CYC-ARC, Ltd., AINSWORTH, A. -R., and MILLER, J. B. March 17, 1950 [April 6, 1949; Jan. 9, 1950], Nos. 9379/49 and 533/50. Class 83 (iv). In stud welding apparatus comprising a body and a stud chuck carrier having a wide range of movement relative to the body, the carrier consists of at least two parts coupled together to permit relative movement thereof equal to the arc length and such that the parts always take up a position in which the relative movement is possible, and electromagnetically operated means for effecting the frictional engagement and retention of the carrier in any position to which it is moved by the butting of a stud upon a plate. In an embodiment, a gun comprises a casing 1 surrounding a solenoid coil 4 and a clutch operating coil 8. A member 17 forms the core of the solenoid 4 and is secured to a magnetic clutch member 18 by a screw 31 in the end of the core 17 which screw passes with clearance through a hole in the end of the member 18. A collar 33 on the end of the screw 31 is acted upon by a spring 29 which urges the members 17, 18 apart. The member 18 slides within a liner 5, in which is mounted a spring 13, a conical ring 15 and abutment ring 23, and slides within an armature 24 which when a polepiece 25 thereon is attracted by a polepiece 10, moves forward to press steel balls 27 arranged about the member 18 into contact with the member 18 and the ring 15 to frictionally retain the member 18. A helical return spring 21 is mounted between the coil 4 and a damping piston 19. A casing 46 carries pins 50 on an interrupted ring 49 which resiliently supports a ferrule 52. In operation a stud is placed against the work and the gun is pressed until the pins 50 engage the work, during which time the core 17 and member 18 have moved into the casing 1 against the spring 21. A switch 44 is pressed to start the welding current and simultaneously energize the coils 4, 8. The pieces 10, 25 move together and the armature 24 effects locking of the member 18. The core 17 moves against the spring 29 until the member 18 is engaged, thus withdrawing the stud and striking an arc. De-energization of the coils 4, 8 allows the spring 21 to butt the stud into the work. The core ring 15 may be replaced by wedges &c. A further piston at the rear end of the member 18 may be used. In a modification, an externally roughened clutch member is retained by magnetic attraction between it and the internally roughened walls of a solenoid former, one coil being used for solenoid and clutch purposes. Two separate coils may be used in this modification and a single coil may be employed in the first embodiment.