US 2005/0028996 A1 · Impact drill

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. In the impact drilling mode, the second ratchet is always out of contact from the main frame and is floatingly maintained within the main frame even if a force ranging from 15 to 25 kg is applied to the main frame toward a workpiece.

Claims27

Dependent claims

An impact drill for boring a workpiece comprising:

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 fixed to the spindle and having a first serrated surface including an alternating projections and recesses;
a second ratchet having a second serrated surface including an alternating projections and recesses and in confrontation with the first serrated surface;
and
a first spring biasing the second ratchet toward the first ratchet, the first serrated surface being abuttable on the second serrated surface upon axial displacement of the spindle, and relative rotation between the first ratchet and the second ratchet causing alternating abutment between the projection and the recess and between the projection and the projection for reciprocating the spindle along its axis;
the first spring providing a spring constant capable of preventing the second ratchet and the spindle from abutting against the main frame when a force ranging from 15 to 25 kg is applied to the main frame for boring the workpiece.

5 more elements

Dependencies are inferred from the claim text.

Impact drill

Life of this patent

Impact drill

Life of this patent

Abstract

Claims27