PURPOSE: To work a reaction required for the acceleration of a moving base as the shaft force of the driving shaft of each linear movement unit and extremely increase rigidity by providing such a constitution as situating a working position in a cross point in which each linear movement unit is crossed to each other at a right angle.
CONSTITUTION: One linear movement unit 19 is driven and moved in a determined direction, and the other linear movement unit 24 is moved in the moving direction of the linear movement unit 19 while being supported by support bases 12a, 12b. Hence, the work position, or a working head is regularly situated in the cross point of the axial lines of both the linear movement units 19, 24 and directly driven by the respective linear units 19, 24. Therefore, the reaction of a force accelerating the masses of a tool shaft 26 and each linear operating unit 19, 24 acts on each linear movement unit 19, 24 as its shaft force.
MURAKAMI SHIN