Friction agitation welding apparatus

A friction agitation welding apparatus for forming a weld across a joint between superposed plate workpieces by rotating a friction agitation welding tool about an axis of welding while urging the friction agitation welding tool and the superposed plate workpieces together in an axial direction of welding whereby generating frictional heat to create a plasticized region in a workpiece material around the friction agitation welding tool and allowing the plasticized workpiece material to solidify to form a weld across said joint said friction agitation welding apparatus comprising:

• a base support;
• a threaded shaft rotatably mounted to said base support;
• a first drive source fixedly mounted on said base support to rotate said threaded shaft;
• an elevating member engaged with said threaded shaft to move along said threaded shaft resulting from rotation of said threaded shaft so as thereby to urge the friction agitation welding tool and the superposed plate workpieces together in the axial direction of welding;
• a first drive shaft mounted to said elevating member, rotatably about the axis of welding but fixedly in movement in the axial direction of welding, and mounting friction agitation welding tool to an distal end thereof;
• a second drive shaft mounted coaxially with said first drive shaft, fixedly in rotation relative to said first drive shaft but movably in an axial direction of said first drive shaft;
• and
• a second drive source fixedly mounted on said base support to rotate said second drive shaft.