Abstract: Drill bits having flushing channels and surface features that cooperate to evacuate cuttings. The surface features can be provided as flutes, fins, and/or ribs defined in a body portion of the bits. Optionally, the surface features can define back-cutting edges the permit back reaming.

Abstract: An expandable reamer apparatus and methods for reaming a borehole are disclosed, including at least one laterally movable blade carried by a tubular body selectively positioned at an inward position and an expanded position. The at least one laterally movable blade, held inwardly by at least one blade-biasing element, may be forced outwardly by drilling fluid selectively allowed to communicate therewith or by at least one intermediate piston element. For example, an actuation sleeve may allow communication of drilling fluid with the at least one laterally movable blade in response to an actuation device being deployed within the drilling fluid. Alternatively, a chamber in communication with an intermediate piston element in structural communication with the at least one laterally movable blade may be pressurized by way of a movable sleeve, a downhole turbine, or a pump.

Abstract: An earth boring drill bit design for alleviating balling varies the junk slot depth in junk slots subject to balling from the other junk slots. Using variable depth bit bodies enhances the hydraulic characteristics of the bit as well as assists in the placement of the nozzles for machining purposes. This flexibility optimizes the area changes along the ducts required by the bit's operation.

Abstract: A boring apparatus is described which comprises a substantially hollow vessel with a fixed base and a rotatable base. The rotatable base is provided, at its circumference, with at least one side cutter which rotatable with the rotatable base from a first position, in which the at least one side cutter serves to cover a respective opening provided in the vessel wall, to a second position, in which the opening in the vessel wall is exposed.

Abstract: A cutter head for retrieving earth samples, in particular for taking underwater samples, has, because of frustum-shaped cutting wheels, an approximately round bore cross section. In an associated boring jig, a tube with a cross section corresponding approximately to the bore cross section is placed above the cutter head. With a regrasping system, the tube can be moved vertically relative to a work table lying on the bore surface. The boring jig may be lowered from a ship to the sea bottom to conduct the boring process.

Abstract: A vertical hole excavating machine having a cutter head comprising: a first head supported rotatably about the axis of a cylindrical shield body at the lower end of the cylindrical body and having a central space vertically extending therethrough; at least one first cutter mounted on the first head to excavate earth under the first head; a second head disposed coaxially in the central space so as to be mounted or dismounted from above, and having a cylindrical portion for receiving matter excavated by the first cutter therein and a bottom plate for closing the lower end of the cylindrical portion; and at least one second cutter mounted on the second head to excavate earth under the second head. It is characterized in that the second head is further provided with a notch to receive matter excavated by the second cutter into the cylindrical portion.

Abstract: A borehole drill construction comprising a cylindrical casing, a chuck mounted on one end of the casing by means of a screw-thread and a cutter head carried by the chuck. The chuck has at least one axially projecting dog thereon which is received in a corresponding recess in the cutter head to provide a means to transmit torque from the casing to the cutter head via the chuck. The cutter head is retained on the bit by at least one plug projecting into a slot in the cutter head, which is permitted limited axial movement thereby.

Abstract: A rubble and core removal apparatus including a casing, open at one end, with spirally extending flighting disposed therein, the flighting being secured to the inner wall of the casing and extending radially inwardly thereof in changing dimension, the casing having a connection to permit rotation and lifting of the apparatus.

Abstract: A hand auger comprises a frustoconical sheet of material split along a lateral strip to form a pair of lateral edges in spaced relation radially and circumferentially. One of the edges is an inner edge of predetermined length and the other of the edges is an outer edge having a length longer than the predetermined length and extending beyond the inner edge at the bottom edge of the sheet. The bottom edge of the sheet is of spiral configuration from the bottom of the inner edge to the bottom of the outer edge. The base edge is of split circular configuration.

Abstract: An underreamer includes a housing and a plurality of underreamer doors, each including a toggle mechanism for selectively extending and retracting the doors. Upon activation of the toggle mechanism thereby extending the doors, the doors are pivoted outwardly from the housing and the tops of the doors are simultaneously moved downwardly. In this manner the overall vertical height of an underreamer adapted to form a given diameter excavation may be substantially reduced.