Patent ID: 7257872

Claim:
An electrode tip dresser for dressing a pair of electrode tips for spot welding held by a welding gun, each of the electrode tips including a tip section and a cylindrical shank section, the tip section having a circular tip surface and an enlarged diameter portion having a diameter increasing as the portion extends from the peripheral edge of the tip surface to the shank section, the electrode tips being held by the welding gun such that the tip sections of the electrode tips are movable toward each other, the electrode tip dresser comprising: a holder which is rotatable in a circumferential direction about a common axis of the electrode tips; a pair of support shafts which are held by the holder, are arranged in parallel in an approach direction of the electrode tips, and extend in a direction orthogonal to the approach direction of the electrode tips; and a pair of dressing rollers which are rotatably supported by the support shafts, respectively, such that the dressing rollers are arranged in parallel in the approach direction of the electrode tips, and which dress the electrode tips to a usable state while rotating in accordance with the rotation of the holder when the electrode tips are pressed against the dressing rollers, respectively, as the electrode tips are moved toward each other, wherein each of the dressing rollers includes a groove which has a cross-section conforming to an outline of the tip section of an associated one of the electrode tips when the cross-section is taken in a direction orthogonal to an associated one of the support shafts, and the outline is taken after the dressing of the associated electrode tip, wherein each of the dressing rollers includes two divided roller bodies, into which the dressing roller is axially divided along a dividing plane, and the dividing plane is arranged in a region extending from a peripheral edge of the tip surface of the associated electrode tip to a center of the tip surface in a direction orthogonal to the axis of the associated electrode tip in a dressed state of the associated electrode tip.