Abstract: A thread joint for transmitting percussive forces includes a male thread on a male member and a female thread on a female member. The male member includes a first portion including an outer surface having a maximum first outer cross section, a second portion having a second maximum outer dimension, and a third portion having the male thread formed thereon. The second portion is disposed axially between the first and third portions. The male thread includes a thread start and a thread end. The third portion terminates in an axially facing first end surface. The female member has a recess in which the female thread is formed, the female thread having a mouth defined by a ring-shaped second end surface. The recess includes a cylindrical inner surface disposed between the second end surface and the female thread. The inner surface faces the cylindrical center portion of the male member.

Abstract: A thread joint for transmitting percussive forces includes a male thread on a male member and a female thread on a female member. The male member includes a first portion including an outer surface having a maximum first outer cross section, a second portion having a second maximum outer dimension, and a third portion having the male thread formed thereon. The second portion is disposed axially between the first and third portions. The male thread includes a thread start and a thread end. The third portion terminates in an axially facing first end surface. The female member has a recess in which the female thread is formed, the female thread having a mouth defined by a ring-shaped second end surface. The recess includes a cylindrical inner surface disposed between the second end surface and the female thread. The inner surface faces the cylindrical center portion of the male member.

Abstract: A male portion for percussive rock drilling includes sections of reduced cross-sectional area. At least one thread for percussive rock drilling is provided at an end of the male portion. The end of the male portion comprises an abutment surface for the transfer of impact waves. The length of the portion is defined as the length of an imaginary cylinder from a plane of the impact surface to a point where the plane ceases to contact a crest of the thread, wherein the length divided by the external diameter of the cylinder lies within a range of 1–2.

Abstract: A male portion for percussive rock drilling includes sections of reduced cross-sectional area. At least one thread for percussive rock drilling is provided at an end of the male portion. The end of the male portion comprises an abutment surface for the transfer of impact waves. The length of the portion is defined as the length of an imaginary cylinder from a plane of the impact surface to a point where the plane ceases to contact a crest of the thread, wherein the length divided by the external diameter of the cylinder lies within a range of 1-2.

Abstract: A drill string for percussive rock drilling includes a series of drill string components which are interconnected by thread joints. Each thread joint includes a male portion on a first of the components, and a female portion on a second of the components which receives the male portion of the first component. Each of the male and female portions includes a screw thread structure. Each of the screw thread structures includes a small-diameter thread and a large-diameter thread which are interconnected to one another by a transition thread. Each of the drill string components includes the male portion at one of its ends, and the female portion at the other of its ends.

Abstract: A thread joint for percussive drilling equipment includes first and second percussive drill string components, the first component including a spigot. An external thread is formed on the spigot, and an internal thread is formed on the second component. Each of the internal and external threads includes an end section gradually transforming into a full thread section. The end section includes a pair of flanks, and the full thread section also includes a pair of flanks. Both flanks of the end section have a different profile than the corresponding flanks of the full thread section.

Abstract: A rock drilling tool includes a pilot bit screw threaded into a front end of a drill rod. A reamer is mounted on the outside of the pilot bit. The reamer includes a central opening having a front portion and a rear portion. The front portion is connected to the pilot bit, and the rear portion constitutes a stiffening sleeve which extends around the outside of the drill rod.

Abstract: The present invention relates to a drilling tool for percussive drilling by means of a top hammer unit, which unit gives compressive pulses. The tool comprises at least one drill tube (12) and a drill bit (11), which cooperates via a connection. The drill bit comprises a bit head (13) provided with crushing means (15) and a shank (17). A shoulder (20) is provided in connection with the bit head, said bit portion having a first abutment surface (21) facing towards a free end of the tube. The free end of the tube facing towards the drill bit is povided with a second abutment surface (23), said top hammer unit being provided to tannsfer compressive pulses to the tube. Each compressive pulse is transferred to the drill bit via the impact surfaces (21, 23). The tube and the drill bit comprise cooperating device (19, 24, 25) for driving and retaining. The tool is defined by that it has a relation between the length of the shank and the length of the bit head that is 5 or more.

Abstract: A drill bit for percussive drilling includes a front surface in which cutting inserts are mounted. A recess is formed in the front surface, and a fluid channel extends through the drill bit for supplying flushing fluid to the recess. The recess is completely bordered by an endless land. Some of the cutting inserts are mounted in the land. Others of the cutting inserts are mounted in the recess in order to be cooled and flushed by a cushion of flushing fluid created in the recess.