Beam carriage type automatic arc welding apparatus with welding head tracking mechanism

In automatic arc welding apparatus having a generally horizontal carriage beam upon which is mounted a movable welding carriage that positions arc welding heads for causing the formation of at least one continuous elongated weld on a work piece to weld angularly related portions of the work piece into integral assembly, wherein the improvement comprises:

• a support arm extending from said carriage;
• at least one welding head guide element being connected in laterally movable and guided relation with said support arm;
• connecting shaft means being movably received by said welding head guide element and having one extremity thereof extending to the vicinity of the work piece to be welded, said connecting shaft means having separate intermediate and terminal sections;
• joint tracking means being connected to said terminal section of said connecting shaft means and being positioned for contact with the work piece to be welded;
• welding nozzle means being connected to said joint tracking means;
• and a first pivotal connector interconnecting said intermediate section and said connecting shaft means and defining a first pivotal axis, a second pivotal connector interconnecting said intermediate section and said terminal section and defining a second pivotal axis being positioned in angular relation to said first pivotal axis, a third pivotal connector interconnecting said joint tracking means and said terminal connector and defining a third pivotal axis, said first second and third pivotal axes providing multi-axis.
• freedom of movement of said joint tracking means enabling said joint tracking means to follow compound curved joints in said work piece, whereby deviation of said joint causes pivotal movement of at least one of said pivotal connection means.