Abstract: An impact drill for boring a workpiece includes a main frame, a motor housed in the main frame, a spindle movably supported by the main frame and rotatable by the motor and movable in its axial direction, a first ratchet positioned fixedly with respect to the spindle, a second ratchet positioned with respect to the first ratchet, a spring biasing the second ratchet toward the first ratchet. The spring has at least one of a spring constant and a biasing force which prevents the second ratchet and the spindle from abutting against the main frame at least one of when a force ranging from 15 to 25 kg is applied to the main frame for boring the workpiece and when the spindle is moved to a retracted position.

Abstract: An impact drill minimizing transmission of vibration to a handle gripped by a user's hand. A spindle extends through a main frame and is movable in its axial direction and rotatable about its axis. A first ratchet is rotatable and axially movable together with the spindle. A second ratchet is axially movable but unrotatable. In an impact drilling mode, the first ratchet is brought into abutment with the second ratchet so that the spindle is reciprocally moved in the axial direction.

Abstract: An impact drill minimizing transmission of vibration to a handle gripped by a user's hand. A spindle extends through a main frame and is movable in its axial direction and rotatable about its axis. A first ratchet is rotatable and axially movable together with the spindle. A second ratchet is axially movable but unortatable. The first ratchet has a first serrated surface and the second ratchet has a second serrated surface in confrontation with the first serrated surface. In an impact drilling mode, the first serrated surfaces is brought into abutment with the second serrated surface so that the spindle is reciprocally moved in the axial direction. A first spring is interposed between the main frame and the second ratchet to urge the second ratchet toward the first ratchet. A second spring is interposed between the main frame and the second ratchet to urge the second ratchet away from the first ratchet.

Abstract: An impact drill minimizing transmission of vibration to a handle gripped by a user's hand. A spindle extends tends through a main frame and is movable in its axial direction rection and rotatablea about its axis. A first ratchet is rotatable and axially movable together with the spindle. A second ratchet is axially movable but unortatable. The first ratchet has a first serrated surface and the second ratchet has a second serrated surface in confrontation with the first serrated surface. In an impact drilling mode, the first serrated surfaces is brought into abutment with the second serrated surface so that the spindle is reciprocally moved in the axial direction. A spring is interposed between the main frame and the second ratchet to urge the second ratchet toward the first ratchet.