The present invention provides a drill comprising: a drill main body rotatable about an axis of rotation, and having a tip end with a tip flank and a shank; a chip discharge flute formed on a periphery of the drill main body, and extending from the tip end toward the shank of the drill main body; and a cutting edge formed along an intersecting ridge where a wall surface of the chip discharge flute facing in the direction of drill rotation intersects the tip flank of the drill main body, wherein ...

The drill of the present invention has only one cutting discharge groove (11) formed in the outer periphery of a bit (10). A leading edge protruding farthest towards the tip in the axial direction in a tip flank (12) is composed at a single point and located on an axis (O). When bit is viewed from the tip side in the direction of axis, tip flank is in the form of a multilevel surface composed of second through fourth flanks (14B, 14C and 14D) arranged along the peripheral direction, and a revers...

A drill including a chisel edge provided at a tip end portion, a spiral first chip discharging groove and a spiral second chip discharging groove, land portions provided between the first chip discharging groove and the second chip discharging groove, and a cut blade provided at an edge of a rake surface of the first chip discharging groove, characterized in that the first chip discharging groove and the second chip discharging groove are provided asymmetrically with respect to a drill rotationa...

A portable power drill having an automatic drilling cycle for feeding a rotating tool bit to a workpiece to effect the desired operation. The drill uses a rotary gerotor pump to pump hydraulic fluid used in its system, and pressurized air to operate the hydraulic pump. The drill has a clamping assembly which clamps the unit on a workpiece before the drill bit is advanced toward the workpiece. The drill also has an integral drill spindle-planet carrier area which adds to its operability and relia...

A drill including an elongate shaft (2) a rear end (5) of which is formed as a shank, and a drilling head (10) provided at the front end of the shaft (2) and having central cutting edges (11, 12) extending from a leading center point (14), which is provided substantially at an extension of a shaft axis, backward toward a circumference of the drilling head, and at least one minor cutting edge (13) a portion (n) of which extending transverse to the shaft axis projects beyond a circumference of the...

A drill includes a substantially cylindrical bit body 10 having an axis O. The bit body 10 has a flange portion 13 which includes a converging portion 13a which reduces its diameter progressively towards the front end of the bit body and a flange 13b which is provided with a rearwardly facing annular surface 13c. The annular end surface is contactable with the front end surface of a drill holding portion of a machine too. Chip discharging flutes 14A,14B, each having an inner surface constituted ...

A drill comprising a solid shank with a first, tip-forming end having cutting edges on opposite second end and a number of flutes corresponding to the number of cutting edges. The flutes extend from the tip end towards the other end and have the purpose of forming and conveying chips from the corresponding cutting edge. At a predetermined distance from the tip, each individual flute turns from a first, chip-forming zone with a predetermined width or cross-sectional area into a second, merely chi...

A drill of simple construction, using commercially available tips or tips obtained by simply modifying them, well balanced in cutting resistance, and capable of drilling small-diameter holes. A main cutting edge (12) of a center-side cutting edge 1 is situated on a base line VP of a circular cone having its vertex on a point V on a tool central axis OO and a half vertical angle .alpha.. An intermediate cutting edge (2) having a length substantially equal to 1/2 of the length of the main cutting ...

A drilling head has a cylindrical body with a longitudinal axis, tapering towards a leading end thereof. The drilling head comprises at least two chip evacuation flutes and at least two lands therebetween. Each flute has a first side all facing in the direction of rotation of the drilling head and a second side wall diverging outwardly from the first side wall and merging therewith via a web-thinning recessed surface extending towards this leading end. Each land is bound by the first wall of one...

A drill for forming bores in constructional components and including a tubular stem (2; 22; 32; 42) having an axially extending through-channel (3; 23; 33; 43) which opens into at least one suction opening (7; 11; 27; 37; 47), a shank (5) provided at a rear end of the stem for connecting the drill to a drilling tool (M), and a drilling head (8; 28; 38; 48) having lips (9; 29; 39; 49) and formed entirely of a cutting material and substantially butt-joined to the stem (2; 22; 32; 42) at a free fro...