Sandvik Ab

Sandvik Intellectual Property Ab

Per-Olof Liljebrand

Urban Olsson

Rainer Beccu

Bo Carlström

Anders Brungs

Christer Lundberg

Jan-Erik Sundstrom

Orban Olsson

H&aring;kan Lindstr&ouml;m

Monica Olsson, Legal Representative

Daniel Lindgren

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. The inner surface has a diameter at least as large as the second maximum outer cross-sectional dimension, and smaller than the first maximum cross section. A first imaginary cylinder constituting an axial extension of the inner surface intersects the first portion of the male member, and a second imaginary cylinder constituting an axial extension of an outermost surface of the female member extends outside of the first portion of the male member.

Thread joint

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&#x2013;2.

Male portion, drill bit and threaded joint for percussive rock drilling

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.

Thread joint percussive drilling equipment

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.

Rock drilling tool and reamer for percussive drilling

Method, drilling tool and rock drill bit for transferring impact energy

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.

Growing community of inventors

Sandviken, Sweden

Per-Olof Liljebrand