Automatic guidance of welding gun along seam by programmed robot - where decoders monitor angular positions of robot to achieve very accurate welding path

摘要

The robot includes a jib arm with adjustable length, and which can be swivelled on two mutually perpendicular axes. On the free end of the jib is a holder for the welding gun, and the holder can be moved in >=2 mutually perpendicular planes. Decoders monitor all the movements of the robot, and feed signals to an electronic comparator fed with pre-programmed values so any deviation can be eliminated. At least the two angular positions of the jib are transmitted to two decoders via pairs of gears or gear segments; and >=1 gear in each pair is pulled against the other gear in the pair by a tension spring. Involute gears are pref. used; and the decoders are pref. fitted on the swivelled gear in each pair of gears.