| 摘要 |
PURPOSE:To prevent corner or uneven contacting of a chucking table mounted to the preceding end of a head with a work piece by making the head provided to the preceding end of an arm freely oscillatable when the arm of a positioning device descends. CONSTITUTION:The root end of an arm 2 is fitted freely oscillatably to a supporting part 1, and is oscillated by the 1st oil hydraulic cylinder 5. The root end of a head 3 is fitted freely oscillatably to the preceding end of the arm 2 and is oscillated by the 2nd oil hydraulic cylinder 6. A chucking table 4 is mounted to the preceding end of the head 3. In the stage of moving the cylinder 5 downward in order to mount the work piece W on a floor to the table 4 or to unload the work piece W mounted to the table 4 on the floor, a solenoid 21a is actuated by the operation of a switch to open a check valve 18 and to free the stroking of the piston of the cylinder 6. Thus the resistance of the head 3 is eliminated and the head is made freely oscillatable, whereby overloading owing to corner or uneven contacting is prevented. |
