PURPOSE: To make engageable well with a groove without searching it with its turning in the rotating direction, by providing several movable guide pins which are guided by a pin guide plate and arranged in parallel to the circumference of a center shaft, and a spring which energizes each movable guide pin in the tip direction.
CONSTITUTION: When a driver bit for adjustment is contacted with its progressing toward the groove 2 of the rotation part 4 of an adjustment object part, a center shaft 14 guides the whole body with a center shaft 14 being fitted to the center of the groove 2. Then, those of the groove 2 part in the movable guide pins 18 of the circumference are energized by a spring 24 and intruded into the groove 2. The movable guide pin 18 excepting the part of this groove 2 deflects the spring 24 and not advanced. Consequently it can be engaged freely to some extent according to the shape of the groove 2.
KURIHARA AKIHIRO
KIMURA NOBUYUKI
