Abstract: For the automatic determination of the diameter of a tool, particularly a saw blade for an automatic wall saw, which is driven by a motor via a gear unit, the moment of inertia of the tool is used as an indicator for its diameter. Three basic solution variants are introduced. In particular, the system including a motor, gear unit and tool is treated as a dual-mass oscillator such that the elasticity of the shafts and gears is arranged as a torsion spring between the inertial masses in two discrete points while taking into account two coefficients of friction including coefficients of the known inertia of the motor rotor (?R) and of the tool (?S). This system can be described by equations which are then simplified by reasonable assumptions or premises. The selected formulations are solved for the moment of inertia of the tool to determine the diameter therefrom and to make an optimal adjustment for the drive possible which is adapted to the respective tool.

Abstract: A control process for an at least partially axially hammering and rotating electric hand-held machine tool (1) in which an electromagnetic clutch (4) arranged in the flow of force between an electric motor (2) and a tool receptacle (3) is controllably connected to computing device (5) connected to sensors (6a, 6b, 6c), wherein the clutch (4) is repeatedly alternately opened and closed in at least one process step controlled by the computing device (5).

Abstract: A control process for an at least partially axially hammering and rotating electric hand-held machine tool (1) in which an electromagnetic clutch (4) arranged in the flow of force between an electric motor (2) and a tool receptacle (3) is controllably connected to computing means (5) connected to sensors (6a, 6b, 6c), wherein the clutch (4) is repeatedly alternately opened and closed in at least one process step controlled by the computing means (5).

Abstract: A hand-held electric machine tool (1) with an at least partly rotary-driven tool receptacle (2) for a tool and a press switch (5) arranged at a handle (4) on the workpiece side for activating the connection of a power source (6) to an electric motor (7) connected to control electronics (10) which are connected to a force sensor (8), wherein the force sensor (8) is arranged between the tool receptacle (2) and the handle (4) and is designed for measuring a pressing force (F) of the hand-held electric machine tool pressing against a workpiece. In addition, an intuitive control process for the hand-held electric machine tool (1) is claimed.

Abstract: A pneumatic percussive mechanism having an axially reciprocating percussive loaded percussion piston (2), wherein a non-contacting magnetic field sensitive sensor (3) is arranged radial thereto. The percussion piston (2) features at least externally ferromagnetic material and has a plurality of axially separated zones (4) of different magnetic permeability.

Abstract: A hand tool device (1), for a partially rotationally driven drill tool (2), including an electronic depth stop (3) with a sensor (4) for non-contacting gauging of a distance and a calculator component (5) for calculating the depth (T) of a drill bit tip (8) relative to a reference surface (10), and signaling when a measured value attains a set value (S). The set value (S) can be transmitted into a set value memory (6) using a single manually operated transfer accept actuation.

Abstract: A hand-held rotary-percussion power tool includes an electrical drive (2) for generating a torque transmittable to a boring tool used with the power tool for forming blind bores, a hammer mechanism (3) for applying impacts to the boring tool, control device (7, 7′, 7″) for controlling operation of at least one of the electrical drive (2) and the hammer mechanism (3), and an electronic depth stop (4). The depth stop include a sensor (5) for contactless, distance measuring of a depth of a blind bore, and a computation unit (6) for generating a signal indicating that a sensed measurement value (M) corresponds to a set value of the depth of the blind bore, and connected with the control device (7, 7′, 7″).

Abstract: An explosive powder charge-operated setting tool having a drive piston (4) for driving a pin-shaped nail (5) in a constructional component in a single drive-in step, and a control circuit (I) for controlling a setting depth (T) and including control electronics (7), a set point generator (8) for setting the setting depth (T), a position-determining sensor (9) for determining a position of a lower dead point (uTP) of movement of the drive piston (4), and a regulator (10) for an automatic adjustment of a motion energy of the drive piston; and a method of controlling the setting depth (T).

Abstract: A positioning aid (1) for a hand tool device (3) driving tool (2), in a working direction (A), with a distance measuring system (4) mounted thereon. The distance measuring system (4) has at least one distance measuring sensor (5) for measuring the distance from the distance measuring sensor (5) to an object (6), along a line of measurement (M, M′, M″), and a computing unit (7) for comparing the measured value with a pre-selected desired value (S) and for producing a signal dependent on the comparison, wherein the line of measurement (M, M′) is oriented at least partially perpendicular to the working direction (A).