A drill bit for chiseling stone includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has, at a front end of the drill head, a cutting edge, an intake opening, and an intake passage. The intake passage connects the intake opening to the delivery passage. A cross section of the intake passage increases from the intake opening to the delivery passage.

A drill bit for chiseling stone includes an impact face at an insertion end of the drill bit, a hollow shank, where a delivery passage is defined within the hollow shank, and a drill head, where the drill head has, at a front end of the drill head, a cutting edge, an intake opening, and an intake passage. The intake passage connects the intake opening to the delivery passage. A cross section of the intake passage increases from the intake opening to the delivery passage.

A tool for breaking rocks comprising a tool head supported by a guide means to be linearly displaceable with respect to the guide between a retracted position and an extended position, a distal end of said tool head extending from said guide to engage a surface to be broken when the tool head is in its extended position; a drive adapted to drive said tool head towards its retracted position in a first operation and to drive the tool head towards its extended position in a second operation, said drive including a drive part mounted on said guide and a driven part mounted on the tool head and engaged by said drive part to be linearly displaceable with respect to the guide upon operation of the drive part of the drive; and a controller adapted to control operation of the drive .

A tool for breaking rocks comprising a tool head supported by a guide means to be linearly displaceable with respect to the guide between a retracted position and an extended position, a distal end of said tool head extending from said guide to engage a surface to be broken when the tool head is in its extended position; a drive adapted to drive said tool head towards its retracted position in a first operation and to drive the tool head towards its extended position in a second operation, said drive including a drive part mounted on said guide and a driven part mounted on the tool head and engaged by said drive part to be linearly displaceable with respect to the guide upon operation of the drive part of the drive; and a controller adapted to control operation of the drive .

The invention relates to an exchangeable wearing part of an arc welding torch, said wearing part being intended to be arranged in the region of an end, provided for carrying out a welding process, of the arc welding torch, wherein the wearing part is provided with a thread on an outer lateral surface and/or on a boundary wall of a recess, an improvement in heat transfer properties and, when such components are conducting, also improved power transmission properties are intended to be achievable. To this end, the invention proposes that, in the direction of a longitudinal axis of the wearing part, a first conical portion, having the thread provided for fastening the wearing part, of the lateral surface or of the boundary wall is followed, on the same lateral surface or boundary wall, by a thread-free second conical portion of the lateral surface or of the boundary wall.

A flat chisel (1) having a longitudinal axis (7), a shank (2) and a blade-shaped working section (5). The shank (2) has a striking surface (4) perpendicular to the longitudinal axis (7). The working section (5) has a cutting edge (3) that is crosswise to the longitudinal axis (7). The cutting edge (3) is configured so as to be saddle-shaped.

A flat chisel (1) having a longitudinal axis (7), a shank (2) and a blade-shaped working section (5). The shank (2) has a striking surface (4) perpendicular to the longitudinal axis (7). The working section (5) has a cutting edge (3) that is crosswise to the longitudinal axis (7). The cutting edge (3) is configured so as to be saddle-shaped.

A device comprising: a bracket adapted to be coupled to a distal end of a robotic arm; a tool holder coupled to said bracket and configured for changeably receiving a first portion of a stone working tool, wherein said tool is movable in a reciprocating axial direction; a driving element for driving said tool distally along said axial direction during a power stroke of said device; and a guiding element for changeably receiving a body portion of said tool and for guiding said tool in said axial direction, wherein said guiding element is configured to resiliently return said tool proximally along said axial direction after said power stroke.

The invention relates to a tool for a power tool, the tool having a longitudinal axis (L) and comprising a working section and a shaft with a connection end for connecting the tool to a tool holder of the power tool, wherein the shaft comprises at least one protruding structure protruding from the shaft. It is characterized in that at least within one of two halves (A, B) of the protruding structure, which are separated by a plane perpendicular to the longitudinal axis (L), the surface of the protruding structure has a finite gradient along a direction parallel to the longitudinal axis (L).

An insert tool, in particular a chisel or a drill, has a tool head, with a shaft region in which a main body is arranged. The main body has a first hardness, and with a coating which has a second hardness that is greater than the first hardness. The coating has chromium carbide or consists of chromium carbide. Advantageously, the durability of the insert tool can be prolonged as a result.