GB968373A - Feeding apparatus for studs and ferrules in stud welding apparatus - Google Patents

Abstract

968,373. Welding by pressure. BIRWELCO Ltd. Jan. 16, 1961 [Oct. 15, 1959], No. 34930/59. Heading B3R. Apparatus for feeding metal studs and ferrules for surrounding the ends of the studs during welding to a welding position, in apparatus for welding studs one at a time to the exterior of a cylindrical workpiece, comprises means for feeding ferrules in a single file along a track, a stop for positioning the leading ferrule with its axis vertical, means for feeding studs in a single file to a position above that occupied by the leading ferrule when so positioned and means for releasing the leading stud in timed relation to the ferrule movement and the operations of the welding apparatus to permit it to fall to a position in which the lower end of the stud enters the ferrule. A tube 4, e.g. for a heat exchanger, is supported at one end by a wheeled carriage 7 on a track 6 and at the other end by adjustable rollers 9. The tube passes through gripping members 10 carried on pivoted members 13 coupled to a piston-and-cylinder device 14 to move the members 10 together or apart, the gripping means being rockable by a piston and cylinder device 15 and associated with a fixed abutment to cause the tube to be axially fed when rotated, as described in Specification 847,692. A second similar, but not turnable, gripping means 17 is provided. Devices 18, 22 for feeding ferrules and studs are mounted on a table 27 above the welding head 3, the devices being vibratable drums which feed the ferrules side-by-side along a track 19 to be discharged against a stop 25 and the studs endto-end to a flexible pipe 21 terminating in the head 3. The studs are received in a member 26 in which the leading stud is clamped during welding by a plunger 28 connected to one side of the welding current supply, the other side being connected to a plunger operated tube contact 54. The member 26 is open to allow the stud to move away therefrom when the tube is rotated. In operation after the leading stud has been welded to the tube, the tube is turned and moved axially and the stud moves out of the member 26. The plunger 28 is moved to a clamping position to arrest the movement of the next stud, the next ferrule moves to its welding position and the plunger is retracted to allow the stud to fall into the ferrule. The member 26 is raised by a fluid-operated device 34, the stud is clamped and then the device 34 is released. The arc welding of the stud, whose end may be aluminium coated, is then effected. As the tube is rotated the ferrules fall away from the studs but a roller 39, which may cause the axial feeding of the tube as set out in Specification 968,374 may crush the ferrules. The ferrules and studs may be brought together at a position removed from the welding head and a piston-operated pusher may move the assemblies one by one to the welding position.