An EDM drill comprised of an automated electrode tube replacing means to allow fully automated and continuous working on holes; and further comprised of an electrode tube guide selection device to allow fully automated and continuous working on holes of various diameters.

A drill bit comprises, on its face, either only curved cutting edges or a combination consisting of at least one straight cutting edge and at least two curved cutting edges. The cutting edges on the face of the drill bit are arranged such that they start from the axis of the drill bit or end directly adjacent thereto. Three channels start from a blind hole serving to attach the drill bit to an anchor rod of an injection boring anchor, and their openings are not located in the area of the face of...

An object of the present invention is to provide a drill bit which is simple in design, high in rigidity, and superior in durability and whose drilling function is in no way inferior to that of conventional drilling bits. To this end, in a drill bit comprising a cutting blade tip 2 which is united tightly to a tip end of a bit body 1 and a plurality of cutting blade portions 2a, 2b and 2c which are formed around the cutting blade tip 2, a flat surface portion 3 is formed in a side surface of the...

A method and apparatus for a drilling with casing includes therewith a drill shoe configured for later drilling through thereof in situ, with cutters retainable thereon in response to the forces encountered during borehole drilling, yet moveable from the envelope through which the later drill shoe will pass when cutting through the in situ drill shoe. The drill shoe includes one or more profiles thereon, into which blades carrying the formation drilling cutters are disposed. The profiles include...

An expandable drill bit comprises a body for mounting on a support string and two roller cutters mounted on the body. The cutters are movable between a smaller diameter first configuration and a larger diameter second configuration. In one embodiment the bit is adapted to drill with the cutters in both the first and second configurations.

A drill template that is operable to locate a position for a hole in a member. The member has at least two distinct surfaces and the drill template includes a body having first and second oppositely-facing sides configured for locating a position for a hole to be drilled in the member. A first alignment member on the first side of the body is configured to align with both a first and a second distinct surface of the member to position the body relative to the member. A second alignment member on...

A drill sharpener is provided which has a point-splitting port which simplifies the procedure for producing a split point on a drill bit undergoing sharpening. The point-splitting port is positioned relative to a grinding wheel assembly such that, when the drill held by a chuck is advanced toward the grinding wheel, a flute of the drill at the drill tip is brought into contact with the grinding wheel. The port has alignment stops therein which mate with flats provided on the barrel of the chuck ...

The invention concerns a drill including a generally cylindrical body, tipped with a head and provided, over at least part of its length, generally spiral evaporating grooves. The groove(s) are delimited, over at least part of their length, by a succession of facets, attached to one another, and linked to one another by sharp edges or by radius blends.

A drill head for use in drilling bores in mines and tunnels has a bit and at least one suction opening (5) for removing drillings and having a crushing profile.

A drill bit constructed to improve a tip end of the cutting pointed portion to efficiently discharge chips from a center portion of a crush face of a drill hole to thereby improve cutting efficiency, is disclosed. A plurality of cutting blades 3a, 3b, and 3c are formed to be arranged in a circumferential direction of a cutting blade chip 3 formed by a cemented carbide block body. The cutting blades 3a, 3b, and 3c are each structured to have a cutting edge 4 formed by an edge between a face 6 and...