Abstract: A friction welding apparatus has first and second clamps for respectively holding first and second parts to be welded by rotary friction welding, a device for producing relative rotation between the first and second clamps and a forge for applying an axial forging pressure to the parts to be welded when the parts are located in the clamps. The second clamp is mounted on a first half of a coupling. A second half of the coupling is movable axially between first and second positions. In the first position the second half of the coupling is engaged with the first half to prevent rotation of the second clamp and enable relative rotation between the first and second clamps. In the second position the second half of the coupling is disengaged from the first half to enable rotation of the second clamp and stop relative rotation between the first and second clamps.

Abstract: A friction welding apparatus has first and second clamps for respectively holding first and second parts to be welded by rotary friction welding, a device for producing relative rotation between the first and second clamps and a forge for applying an axial forging pressure to the parts to be welded when the parts are located in the clamps. The second clamp is mounted on a first half of a coupling. A second half of the coupling is movable axially between first and second positions. In the first position the second half of the coupling is engaged with the first half to prevent rotation of the second clamp and enable relative rotation between the first and second clamps. In the second position the second half of the coupling is disengaged from the first half to enable rotation of the second clamp and stop relative rotation between the first and second clamps.

Abstract: A welding torch (10) for welding on a component has an electrode (12) within a nozzle (14) through which a flow of gas passes. A shield (20) defines an enclosure (22) around the nozzle (14). Means are provided for supplying weld filler material (18) into the vicinity of the electrode (12) through the shield (20). One end of the shield (20) is attached to the welding torch (10). The other end of the shield (20) is open and extends towards the component (16). An inflatable seal (28) is mounted on the end of the shield (20) to seal between the shield (20) and the component (16).