Power tool having an operating knob for controlling operating in one of rotary drive and hammering modes

A power tool includes a housing, a fixed ratchet seat, a drive spindle, a rotatable ratchet, and an operating knob. The ratchet seat is disposed immovably in the housing. The drive spindle extends rotatably through the ratchet seat and is axially movable between front and rear limit positions. The rotatable ratchet is mounted on the drive spindle for co-rotation therewith, and disengages the fixed ratchet seat when the drive spindle is at the front limit position, and engages the fixed ratchet seat when the drive spindle is at the rear limit position. The operating knob is sleeved rotatably on the housing, and is rotatable to drive rotation of a switching ring in the housing. The switching ring is associated operably with a latching seat on the drive spindle to enable and disable movement of the drive spindle between the front and rear limit positions.