AUTOMATIC SCREW TIGHTENING APPARATUS

PURPOSE:To facilitate coincidence of a screw held onto a screw chuck with the tapped hole on a work by freely inserting a driver bit into the lower base in shiftable ways in the horizontal direction and installing an elastic body between a screw chuck connected to the above-described bit and the lower base. CONSTITUTION:Screws 15 are sent one by one into a plurality of screw chucks 10. A driver driving part 12 is operated, and a driver bit 11 is revolved through an automatic joint 13 and a drive shaft 14, and at the same time, an air cylinder 14 operates to lower the upper and the lower bases 7 and 9 all together. Then, the driver bit 11 lowers, revolving in the screw chuck 10, and a screw 15 is screwed into a tapped hole on a work 16. In this case, the driver bit 11 is freely inserted into the hole 7a on the lower base 7 in shiftable ways in the horizontal direction, and a spring 17 is fitted between the lower base 7 and the collar part 10a of the screw chuck 10. Thus, the screw chuck 10 can be shifted in the direction of center of the tapped hole, and the coincidence of the screw 15 with the tapped hole is facilitated.