Tool holder head, particularly for welding yokes and guns

Claim 1

A tool holder head for mounting on machines movable along two or more axes, particularly for supporting a welding yoke or gun for welding sheet metal workpieces for making metal casings and the like, which comprises: a bushing rigidly mounted on a movable support of said machine; an outer hollow shaft having at one end a first journal bearing arranged at an oblique axis to and intersecting the axis of said shaft; an intermediate hollow shaft rotatably and coaxially mounted within said outer hollow shaft and having a first bevel gear at the end adjacent said first journal bearing; an inner shaft rotatably and coaxially mounted within said intermediate hollow shaft and having a second bevel gear at the end adjacent said first journal bearing; first driving means on said bushing for rotating said outer shaft by desired angular increments with respect to said bushing; second driving means on said outer shaft for rotating said intermediate shaft by desired angular increments with respect to said outer shaft; third driving means on said outer shaft for rotating said inner shaft by desired angular increments relative to said outer shaft; a first driven member rotatably mounted on said first journal bearing and having a third bevel gear meshing with said first bevel gear, said first driven member including a second journal bearing arranged coaxially to said first journal bearing and a third journal bearing having an oblique axis relative to and intersecting the axis of said second journal bearing; a second driven member rotatably mounted in said second journal bearing and having a fourth bevel gear meshing with said second level gear, said second driven member being further provided with a fifth bevel gear opposed to said fourth bevel gear, and a third driven member rotatably mounted on said third journal bearing and having a sixth bevel gear meshing with said fifth bevel gear, said third driven member supporting a tool.