A drilling bit comprising a drill body formed from a base portion and a crown portion having a plurality of cutting elements; the base and crown portions are interengaged by a connection portion. An external opening in the crown portion communicates with a core-receiving section in the connecting portion. A core milling assembly, comprising a pair of rotatable, frustum-shaped rotary members, is supported in the connecting section. Each rotary member carries a plurality of cutting elements. Durin...

A bit breaker adapted to be fitted in the Kelly drive of a drill rig for detachably securing a rotary drill bit to the Kelly drive to enable the latter to rotate the bit relative to a drill string having an internally threaded lower end portion in one direction to effect a threaded connection between the threaded pin of the bit and the string, and in the other direction to disconnect the bit from the string. The bit breaker comprises a bottom engageable by the bottom of a drill bit for supportin...

An improved bit for use in drilling masonry and the like. This bit is of the type having a transverse bar of hardened material in the tip thereof with symmetrical end surfaces sloping away from a central chisel edge located on the axis of the bit. One of these surfaces is provided along its length with a groove extending from a cutting lip to the trailing edge, with the groove width and depth at the trailing edge having at least the same dimensions as at the cutting edge. Preferably the dimensio...

A bridoon bit with curb arms is provided with a thickened center portion having a curved lateral axis, and with end portions outwardly thereof having an opposite curvature in order that the bit may best conform to the anatomy of a horse's mouth, avoiding pressure points and preventing the horse's mouth from becoming insensitive.

A drilling bit having two helical withdrawal grooves which extend from the drilling head in the direction toward the insertion or chucking end. The withdrawal grooves have least slope in the vicinity of the drilling head. In the other regions, the withdrawal grooves have a different slope. As a result, no cross-sectional jumps disposed at uniform intervals are provided on the drilling bit, so that transverse oscillations cannot be reinforced by partially constantly or continuously reflected puls...

A drill bit comprises a body having a shank portion and an end face at its forward end. The drill bit body has at the forward end a cutting means having at least one cutting edge provided on the end face. The cutting edge is spaced from the axis of rotation of the body. The body has a rake surface which terminates in the cutting edge and extends along the axis of rotation.

The bit for horses comprises a bit bar formed from a moulded article with an oval or circular cross-section and made from a resilient-elastic material having a high abrasive resistance, which conically widens from the center of the two moulded article ends provided with the through-bores for rings for fixing the reins, accompanied by the formation of a central, narrow, resilient-elastic web extending over a short section and has frontally flattened horse tongue contact surfaces, which leads to a...

A drill bit for use in combination with a through-the-steel drill stem, the drill bit including an elongated body portion having a bore through which cuttings may be removed through the drill stem, a web for receiving a drill tip, and a sleeve attached about the body portion thereof, the web thereof having axially extending faces coutoured from the periphery of the body portion toward the axis thereof, and the sleeve extending from the body portion and in spaced apart axial relation to the conto...

A router bit comprises a shank and a fluted portion, for example two or four fluted bit. The two fluted bit comprises two upper cutting edges higher than a predetermined standard line and two lower cutting edges lower than the standard point. Helixes of the upper and lower cutting edges are twisted in the opposite direction relative to each other. Helix angles of the upper and lower cutting edges are equal or different in absolute angle.

A rotary bit having a pair of semi-spheres rotating about a shaft extending from a center tongue. The semi-spheres include a plurality of cutters arranged in a predetermined fashion to maximize cutting efficiency. The semi-spheres may be disposed slightly off-center from the bit's axis of symmetry to bias the bit in a particular direction.