Abstract: An automatic evacuation drilling bucket comprises a follower formed with a working space for receiving a blade member which is capable of coming in contact with an osculating arm, the working space having upper, lower, transition and receiving compartments. If the blade member is located in the upper and lower compartments, the blade member is engaged with the follower when a drive shaft member is rotated in the normal and reverse directions. If the blade member is urged to move into the receiving compartment through the transition compartment, the blade member comes in contact with the osculating arm when the drive shaft member is rotated in the reverse direction.

Abstract: An under reaming pile bore excavating bucket by which an under reamed part of a pile bore is excavated and the excavated soil is moved into the bucket for easy removal of the soil. In use, the bucket is lowered to the bottom of an already excavated straight pile bore; side apertures of the bucket are opened; the slidable wing drill bits are rotated and moved downward and outward along guide rails to excavate an under reamed part. The excavated soil is taken into the bucket through the side apertures and openable bottom apertures. When the drill bits reach their lowermost position, the drill bits are rotated reversely to house the drill bits again into the bucket and lastly the side apertures are closed. The soil within the bucket is raised from the excavated pile bore. In particular, a drive shaft is spline engaged with an outer pipe fixed to the center of the bucket body for allowing the slidable bits to rotate and further move downward or outward.

Abstract: An under-reaming pile bore excavator by which a straight pile bore is first excavated vertically to a given depth by rotating the main drill bits and the under-reamed bore is next excavated downward and outward into a given shape by rotating the slidable wing bits. The under-reaming pile bore excavator of the present invention comprises a plurality of guide rails, and a plurality of slidable wing bits mounted on the guide rails which excavate the under-reamed bore, in addition to the conventional main drill bits which excavate the straight pile bore. In using the under-reaming pile bore excavator of the present invention, it is possible to obtain a stable impermeable soil surface on the excavated bore to prevent water from penetrating into the soil wall and to prevent lumps of soil from being dislodged therefrom.

Abstract: An under-reaming pile bore excavator by which a straight pile bore is first excavated vertically to a given depth by rotating the main drill bits and the under-reamed bore is next excavated downward and outward into a given shape by rotating the slidable wing bits, allowing a relatively larger diameter ratio of the under-reamed pile bore to the straight pile bore. The under reamed pile bore excavator of the present invention comprises a plurality of guide rails disposed so as to cross the axis of the drill pipe, and a plurality of slidable wing bits mounted on the guide rails which excavate the under-reamed bore, in addition to the conventional main drill bits which can excavate the straight pile bore.

Abstract: An under-reaming pile bore excavator by which a straight pile bore is first excavated vertically to a given depth by rotating the main drill bits and the under-reamed bore is next excavated downward and outward into a given shape by rotating the slidable wing bits. The under-reaming pile bore excavator of the present invention comprises a plurality of guide rails, and a plurality of slidable wing bits mounted on the guide rails which excavate the under-reamed bore, in addition to the conventional main drill bits which excavate the straight pile bore. In using the under-reaming pile bore excavator of the present invention, it is possible to obtain a stable impermeable soil surface on the excavated bore to prevent water from penetrating into the soil wall and to prevent lumps of soil from being dislodged therefrom.