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.

A drill bit (10) comprises a cast body (12) with full length wide overlapping integral spiral stabilizer lands (14) between intervening spiral grooves (16), integral short, strong, stubby spiral fingers (18) reinforced by additional web portions (12a) angularly spaced about a short core receiving bore (b) and the longitudinal axis of the body (21). An inclined core ejection passage (P) extends radially outwardly from a spherical inlet end thereof connected to the core receiving bore (b) and at w...

A nonrotatable excavating bit comprising a forward working portion and hard wear resistant material attached thereto and having a rearward shank portion which is circular in cross section and is adapted to fit into a circular bore of a support block. An abutment shoulder is formed at the juncture of the forward working portion and rearward shank portion and a tang extends from the shoulder and is adapted to fit down over and mate with a surface of said support block so as to hold the bit nonrota...

A rotary drag bit is disclosed which eliminates the problem of the disorientation and dislodging of cutting elements on the bit body. The drag bit includes a replaceable head cover which is adapted to be removably attached to the face and gage surfaces of the bit body head portion. The head cover is preferably made of tungsten carbide and includes a plurality of projections integrally formed thereon. These projections function as a backing and include a planar surface for receiving a plurality o...

A drill bit comprising a shank having three cutting blades extending radially therefrom with the longitudinal cutting edges of the blades defining a right circular cylinder coaxial with the axis of the shank. At the working end of the shank a countersink cutting point is formed by the cutting edges of the blades sloping together to a common point on the axis of the shank and defining a right circular cone.

A router bit is provided with an even number of paired cutting edges. Each pair of cutting edges has opposite helix hands at the same helix angle with respect to the axis of rotation and a portion where the pitch of the cutting edge is constant when the cutting edge is developed along the circumference of rotation in the longitudinal direction. Such router bit is suitable for chamfering and finishing the side of board containing fiber reinforced plastics.

A roller bit for rock drilling comprising a body having at least one stub axle and a geared cutting element rotatably mounted on said stub axle. The stub axle and cutting element have confronting spaced raceways for a plurality of rolling elements. A shoulder is formed adjacent one end of the raceway in the stub axle to axially fix the rolling elements in one direction. A locking ring is mounted in the cutting element having an abutment shoulder confronting the opposite axial end faces of the ro...

A rotary drilling bit having at least one cutter rotatably supported in a rolling bearing on a trunnion of the drilling bit body. An edge ring is provided with a seal fixed in the bored hole of the rotary cutter between the rollers of the rolling bearing and the drilling bit body which axially guides the rollers in one direction. The edge ring has a machined surface which faces the outside surface of the trunnion defining therebetween a narrow annular gap and the seal consists of at least one ra...

A drilling bit has cutting edges radiating from its axis, each being a segmental part of a circular cutter the axis of which is substantially tangential to a circle centered on the bit axis, the cutters being at different distances from the bit axis. The cutters may be rotated to enable worn cutting edges to be replaced and the extremities of all cutting edges are substantially in a plane normal to the bit axis.

A percussive rock drill bit of a type generally known in the art as a button bit wherein a plurality of wear-resistant metal inserts project from the working face of the drill bit. An elastomeric sleeve surrounds that portion of the sides of the insert which is embedded in the bit body. There is metal to metal contact be between the end of the insert and the bit body for transmitting blow energy from the bit body to the insert.