Abstract: There are provided an electrode tip dressing apparatus and an electrode tip dressing tool for resistance welding, which are miniaturized by reducing a rotational driving-force of a dressing tool. By adjusting a curvature radius of a dressing portion 4 of a dressing tool 2, a contact width, wherein a top electrode tip 5 abuts to the dressing portion 4 of the dressing tool 2, is adjusted from a rotational center of the dressing tool 2 to the outer side of the dressing tool 2. Dressing work done with the dressing tool 2 is thus made to be constant at the whole area of the dressing portion 4, from the rotational center of the dressing tool 2 to the outer side of the dressing tool 2. Accordingly, excess dressing work, which brings decline of productivity, can be avoided, thus enabling to dress the top electrode tip 5 with the minimal dressing work. A rotational driving-power of the dressing tool 2 is thereby reduced, enabling to labor-save and miniaturize the electrode tip dressing apparatus.

Abstract: There are provided an electrode tip dressing apparatus and an electrode tip dressing tool for resistance welding, which are miniaturized by reducing a rotational driving-force of a dressing tool. By adjusting a curvature radius of a dressing portion 4 of a dressing tool 2, a contact width, wherein a top electrode tip 5 abuts to the dressing portion 4 of the dressing tool 2, is adjusted from a rotational center of the dressing tool 2 to the outer side of the dressing tool 2. Dressing work done with the dressing tool 2 is thus made to be constant at the whole area of the dressing portion 4, from the rotational center of the dressing tool 2 to the outer side of the dressing tool 2. Accordingly, excess dressing work, which brings decline of productivity, can be avoided, thus enabling to dress the top electrode tip 5 with the minimal dressing work. A rotational driving-power of the dressing tool 2 is thereby reduced, enabling to labor-save and miniaturize the electrode tip dressing apparatus.

Abstract: An industrial robot is constituted by a plurality of series connected arm units each composed of a driving unit from among a plurality of driving units having different driving powers and different driving speeds, a joint unit from among a plurality of joint units having different driving speeds and power transmitting capacities, and an arm from among a plurality of arms having different sizes and load capacities. The joint units, driving units and arms each have connecting surfaces thereon having positioning parts and setting-fixing parts in a predetermined pattern for enabling the joint units, driving units and arms to be detachably connected to other joint units, driving units and arms at corresponding connecting surfaces to form arm units with the desired joint units, driving units and arms. The joint units each have a stationary frame and a follower frame rotatably connected to each other and driving power transmitting mechanism connected between said frames and including reduction gears.