Patent ID: 7021400

Claim:
A power tool for use with a working element, the power tool being operable in either a working mode or an adjustment mode, the power tool including: a driven member having a body part and an adjustment part that when in the adjustment mode are moveable relative to one another to grip or release the working element, and when in the working mode the body part and adjustment part move together to drive the working element to enable the working element to perform work, a power drive including a motor and a gear assembly through which the motor is connected to the body part to drive the body part at either a slow speed or a relatively fast speed about an axis of the power tool, a lock operable to engage said adjustment part and enable the adjustment part to move relative to the body part when the body part is driven by the power drive, the lock includes a locking sleeve having a bore formed with a plurality of splines formed on an inner surface of the bore, the adjustment part including a plurality of complementary splines formed on an outer surface thereof, the splines of both the locking sleeve and adjustment part having a major length dimension that extends in the direction of the axis of the power tool allowing the locking sleeve to move in the direction of the axis of the power tool so that the locking sleeve surrounds the adjustment part to enable the splines of the locking sleeve to mesh with the splines of the adjustment part when the power tool is in the adjustment mode, and disengage from each other when the power tool is in the working mode; and a selector operable to cause the power tool to operate in the working mode or the adjustment mode, the selector being connected to the locking sleeve to move the locking sleeve to cause said locking sleeve to engage with or disengage from said adjustment part, the selector being connected to the gear assembly to enable adjustment of the power drive between the slow speed and the fast speed, whereby the connection of the selector to the gear assembly and the locking sleeve is such to limit the power drive to driving the body part at the slow speed when the power tool is in the adjustment mode.