Patent attributes
A vibration drill unit capable of obtaining an intensive drilling force. The vibration drill unit includes a first ratchet, anon-rotatable second ratchet having a claw engageable with the claw of the first ratchet, and a main body frame for accommodating a motor, a spindle, the first ratchet and the second ratchet. The respective claws of the first ratchet and the second ratchet include the first inclined surfaces formed so as to be engaged in the rotation direction by rotations of the first ratchet and so as to be separated from each other, the second inclined surfaces having greater inclination in the reversed direction than the first inclined surfaces, top parts that link the upper parts of both inclined surfaces to each other, and flat parts that link the bottom parts of both inclined surfaces to each other.
