Patent ID: 7673701

Claim:
A power tool comprising: a driving unit for performing screw tightening operations; a motor for rotatably driving the driving unit; a rechargeable battery pack; a trigger switch for turning on and off the motor; and a control circuit, accommodated in a main body of the power tool, for monitoring the screw tightening operations, wherein the control circuit has a screw tightening completion detection unit for detecting completion of a screw tightening operation; a screw tightening count unit for counting the number of completed screw tightening operations detected by the screw tightening completion detection unit; a screw tightening number setting unit for presetting the number of screws to be tightened; and a screw tightening completion notifying unit having a piezoelectric buzzer for notifying completion of the screw tightening operations when the number of completed screw tightening operations reaches the preset number of screws, and wherein the screw tightening number setting unit and the screw tightening completion notifying unit are disposed at a lower front portion of a grip portion in the main body of the power tool, for being held by a hand, wherein the piezoelectric buzzer produces one of selectable alarm sounds having different pitches.