WELDING DEVICE

A tool holder for a manipulator comprises a tool shaft extending along and rotatable about a main axis and having a tool-shaft end provided with a pivot defining a transverse axis. A tool is carried on the pivot and is displaceable relative to the tool shaft about the transverse axis. A stack of guide rings coaxially surrounds the tool shaft adjacent the pivot and is formed with at least two throughgoing guide-ring passages each having a radially outwardly opening passage end. Two of the guide rings define a pair of axially spaced annular confronting guide-ring surfaces. A connector ring is rotatable on the stack between the guide-ring surfaces and has a pair of axially oppositely directed connector-ring surfaces one of which axially directly confronts one of the guide-ring surfaces. A connector element secures the connector ring to the tool-shaft end for joint rotation of same about the main axis. A flat contact element is secured to one of the one surfaces and is axially flatly engageable with the other of the one surfaces. Thus current can be transmitted between the connector ring and the guide ring of the one guide-ring surface by the contact element. A piston-and-cylinder assembly and a spring are engaged between the connector ring and the other of the guide-ring surfaces for pressing the one surface and contact element together axially. An electrical feed line is connected to the conductor fixed to the support and an electrical line is connected between the other conductor and the tool for feeding electricity through to the tool.