GB735105A - Improvements in or relating to electric arc stud welding or soldering guns - Google Patents

Abstract

735,105. Welding by pressure. SVENSKA AKTIEBOLAGET GASACCUMULATOR. Nov. 23, 1951 [Nov. 30, 1950], No. 27531/51. Class 83 (4). An electric arc stud-welding or soldering gun has two displaceable units, one of which carries the stud and the other of which is displaceable by a solenoid through a predetermined distance and means for interlocking the units so that they move together to form the arc, the interlocking means comprising on the solenoid displaceable unit a clutch having a pivotal part or parts which under the direct influence of magnetic force engage and interlock the other unit. In one embodiment a gun comprises a housing 1, Fig. 1, having a part 3 forming with a nut 4 a collet chuck 3a within which is carried a sleeve 5 having a porcelain ferrule 6 thereon. A stud 10 held in a chuck 9 on one end of a rod 8 forms one unit with a member 11 secured to a tube 12, on the other end of the rod 8. The member 11 under a spring 43 normally abuts a member 7 in the housing 1 while the tube 12 extends into a solenoid 13 having a core 23. Slidable in the tube 12 is the other unit comprising two clutch members 16 with extensions 18 and pivoted on a pin 17, the outer surfaces of the members 16 being normally conical while the end surfaces 21 are bevelled to match those 22 of the core 23. This unit is normally urged by a spring 20 in the tube 12 against a pin 24 held by a spring 26 to project from the core 23. In operation the gun is pressed on the work until the stud 9 and ferrule 6 both engage it, thus forcing the member 11 against the spring 43 and the tube 12 into the solenoid 13. The clutch device slides in the tube 12 since spring 26 is stronger than spring 20. Current is then supplied to both the solenoid 13 and to the stud 9 and work. The members 16 firstly under magnetic force pivot about pin 17 to lock themselves on the tube 12 and then move against spring 26 until the faces 21, 22 engage. The two units moving together lift the stud 9 from the work to strike an arc. On switching off the current the solenoid 13 is de-energized and the members 16 return to normal positions while spring 43 thrusts the stud 9 into the work. In a modification a hook 31, Fig. 2, pivots in the tube 35 under magnetic force while sliding on the pin 24 to lock itself in the tube 35. Specifications 681,585 and 681,586 are referred to.