Patent ID: 7823483

Claim:
A working depth adjusting device for a rotary tool having a tool body and a spindle rotatable about an axis, wherein a tool bit can be attached to the spindle so as to be rotatably driven, and the rotating tool bit can be pressed against a workpiece for processing the workpiece, the working depth adjusting device comprising: an adjusting member constructed to be attached to the front portion of the tool body and movable along the axis of the spindle, so that the position of the adjusting member can be adjusted relative to the tool bit with respect to a working depth direction; an intermediate member rotatably mounted to the adjusting member, wherein the adjusting member can move in the working depth direction as the intermediate member rotates; and an operation member operable to rotate relative to the intermediate member between a lock position and an unlock position; wherein the intermediate member has a first engaging member; wherein when the operation member is rotated to the lock position, the first engaging member engages the tool body, and the engagement of the first engaging member is maintained by the operation member, so that the working depth adjusting device can be prevented from being removed from the tool body; and wherein when the operation member is rotated to the unlock position, the first engaging member is disengaged from the tool body, so that the working depth adjusting device can be removed from the tool body.