Patent ID: 7165481
Filing Date: 2007-01-23
Classification: B25B

Abstract:
1. A screwdriver comprising: a driver portion that includes a motor; an output shaft rotated by the motor; a housing accommodating the motor and the output shaft, and a bit fitted at the end of the output shaft; a barrel-shaped slider case fixed to the housing so as to insert the bit, the barrel shaped slider comprising a guide slot; a slider supported in the slider case, the slider capable of reciprocating; an arm portion rotatably supported in the slider; the arm portion engaged with the guide slot of the slider case, and the arm portion oscillating in accordance with the reciprocation of the slider; and a cylindrical drum rotatably supported in the slider, the cylindrical drum intermittently delivering the screw chain belt in accordance with oscillation of the arm portion, and the cylindrical drum comprising; two flanges engaged with a screw chain belt; and a ratchet engaged with the arm portion, wherein the ratchet of the drum is formed on an inner surface of one flange facing the other flange.