This invention relates generally to improved means for securing a working member within a rotary tool and is described hereinbelow with particular reference to a percussively actuatable striking bar secured by the novel securing means hereof within a percussive rock drilling apparatus.

The drill invention relates to forming holes in circuit boards and the like. Smoother holes may be formed faster by reducing tendencies of drills to chip. The drill (11) employs primary and secondary reliefs (28,29) behind cutting lips (27) to provide lesser and greater clearances, thereby strengthening the cutting lips' outer edges. The margins (10) having lengths variable in width (20,21) and variable in helix angle (22,23) facilitate the foregoing.

A drill formed with chip discharging flutes in its shank and having a flute width ratio of 0.5 to 0.02 to give increased torsional rigidity to the drill shank, the drill being adapted to form holes, especially deep holes, with an improved cutting efficiency.

The invention relates to a drill for metal drilling, comprising a drill body and a drill tip provided with cutting portions. The drill tip is detachably secured to the drill body by means of fastening devices, which are arranged on opposite sides of the centerline (CL) of the drill. The planar lower face of the drill tip is provided with a central tap which engages in a central recess in the mainly planar front surface of the drill body in order to center the drill tip relative to the drill body...

A drill bit consists of a bit body having a forward end and a slot in the forward end to hold a hardened cutting blade. The blade has a central slot extending into the forward end thereof such that the slot defines inner side wails and a bridge extending between the inner side walls. A protrusion along the leading face of each of the cutting sides of the blade with each protrusion extending to the forward edge extends the length of the cutting edges and by distributing the load along a greater l...

A drill guide is disclosed including a sleeve mounted on a handle. The sleeve of the drill guide has a bore which is dimensioned for slidably receiving a bit sizing ferrule therein. The bit sizing ferrule has a sized bore for demountably inserting a drill bit or other instrument therein having a particular width.

A drill with a drill point part that contains the drill cutter and is made of a solid hard material. The drill point part is replacably attached to the end face of a drill shaft. The drill shaft is penetrated by a shaft groove which extends in an axial direction of the shaft to accomodate the drill point part and can center the drill point part in the groove region. The drill shaft has grooves on its periphery which run in the axial direction and extend into the region of the shaft groove and co...

A drill comprising, a central cutting edge tip which is arranged on an axial portion of a distal end of a spindle body, and a peripheral cutting edge tip which is arranged on an outer peripheral portion of the distal end of the spindle body, each of the tips including a tip body, the central cutting edge tip being arranged so that its longitudinal direction is parallel with a radius direction of the spindle body, a long-side cutting edge and a long-side corner cutting edge adjacent to an axial s...

A drill bit, such as a twist drill, having a body equipped with flutes, as well as a drill bit face that includes two main cutting edges that merge together. In order to drill a blind hole, such as with a level drilled bottom, the main cutting edge forms a continuous cutting edge that runs in a plane perpendicular to the drill bit's longitudinal axis. The main cutting edges, with respect to a cutting direction, are arranged behind a center line lying in the plane which is perpendicular to the lo...

A drill attachment (10) for decreasing the rotational speed/increasing the output torque of a cutting accessory (14) that is attached to a drill such as a surgical drill (10). The drill attachment has an input drive shaft (34) that is coupled to the drive shaft (16) of the drill to rotate in unison with the drill drive shaft. The input drive shaft rotates a set of axially fixed input planet gears (58). The input planet gears rotate a ring gear (66) that is fitted around the input planet gears. T...