Abstract: An underreamer tool has a body with upper and lower portions having an upper cutter blade slot extending transversely through the upper portion and a lower cutter blade slot extending transversely through the lower portion at a right angle thereto. The upper and lower portions have central bores separated by a wall and connected by upper and lower fluid flow passageways bypassing the cutter blade slots. An upper pair of cutter blades mounted in the upper cutter blade slot and a lower pair of cutter blades mounted in the lower cutter blade slot move between a retracted position within the slots and an extended position outward therefrom. An upper piston in the central bore above the upper cutter blade slot has its bottom end engaged on the upper cutter blades and a lower piston in the central bore above the lower cutter blade slot has its bottom end engaged on the lower cutter blades.

Abstract: A drilling tool is followed by a casing tube (11) down the drilled hole. The mouth of the casing tube (11) centers rotatably a guide member (10) which receives rotation and impact energy via the interior of the casing tube (11). A drill bit (20) consists integrally of an axially protruding pilot portion (23), a sidewise projecting eccentric portion (22) and a rear shaft (21). The shaft (21) extends pivotally and axially movably into an eccentrically disposed bore (24) in the guide member (10). Axially spaced peripheral end grooves (30,32) extend in opposite direction from an axial cam groove (31) on the shaft (21) and are engaged by a follower (28) in the guide member (10) defining positively the axial and angular movability and positions thereof relative to the drill bit (20). In the forward end groove (32) the follower (28) maintains the drill bit (20) axially in drilling position (FIG.

Abstract: An apparatus for use in energy exploration is disclosed which is used where a radially expanding device is required, for example in a stabilizer, retriever or an underreamer. The apparatus comprises a support tubular member for connection to a drilling string, the member supporting a movable member which is axially movable along the member. A further member which may either be fixedly secured or also axially movable along the member is axially spaced from the movable member. The movable member and, optionally, the further member have tapered outer surfaces which cooperate with a taper on a radially movable member. The arrangement is such that movement of the movable member in the axial direction is such that the cooperating tapers cause the radially movable member to expand or contact in the radial direction. Various means for securing and performing radial movement are disclosed.

Abstract: This disclosure relates to a drill for forming an undercut cavity in a hole in concrete, for an anchor bolt. The drill has forward and rearward ends, and comprises a body having an axially extending bore forming a generally cylindrical wall, the bore being open adjacent said forward end. A wedge center is slidably mounted within the bore, and connecting means is fixed to said center and axially slidably engages the body so that the body and the center rotate together. The center is spring-urged toward the forward end relative to the body. The body has a blade adjacent its forward end and a cutting tooth is fixed to the blade. The center has guide jaws adjacent said forward end and the jaws extend radially outwardly toward the forward end, whereby as the body moves toward the forward end relative to the center, the blade slides on the jaws and the tooth moves radially to form the cavity.

Abstract: Apparatus for extracting core samples from the side walls of a subterranean well bore comprises an axial force generating tool insertable into the well with such tool carrying a stationary support rod and the movable element of such tool producing a movement of a housing surrounding the stationary support rod. Annular core forming tools are mounted on plural anvil plates disposed on sides of the stationary support rod and such tools are moved into penetrating relationship with the well bore side wall through association with a linkage between the movable housing, the anvil plates, and the stationary support rod. The movement of the axial force generating element is opposed by a resistance element. A limit to the maximum force applied to the core forming tools is provided by a shearable element series connected in the stationary support rod.

Abstract: Retractable core drill bit having a hollow cylindrical body at its lower end to which a monolith core drill bit is screwed. A stop sleeve is provided on the upper end of the hollow cylindrical body, and cutting components are pivotally mounted in the middle of the body. There is a spacer in the body having an end piece on its upper end around which there is driven a guiding sleeve resting on a stop sleeve which is surrounded by a outer end piece and an outer tube. There are longitudinal slots in the body for the radial movement of the cutting components which are disposed opposite to each other in interperpendicular planes.

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 apparatus consisting of pipe sections pivotally joined which can be insert in a borehole when in straight position and manipulated to a zigzag position to loosen minerals outside the wall of the borehole.

Abstract: The method and apparatus for drilling a well bore and setting a liner therein in which the drill string with a bit and underreamers thereon also includes a liner supported thereon which has a gripping assembly with two sets of gripping elements and a pair of external tapers on the liner each of which coacts with one of the sets of gripping elements, one of which wedges one set of gripping elements into set position responsive to the liner weight and the other of which is spaced from said one a sufficient distance that said one is removed from wedging engagement when said other wedges the other set of gripping elements into set position responsive to upward forces on said liner, and a normally closed bypass around the sealing means on the liner which may be opened responsive to manipulation of the liner to allow cementing of the liner in position within the well bore and the steps of lowering the liner on the drill string as the well bore is being formed, setting the liner, gripping assembly and sealing means,