Abstract: A method for operating a power tool is provided. The power tool has a tool, in particular a drill bit, and a motor, while the motor is a brushless electric motor. In the power tool there is implemented a rotational speed graduation of an electronic form, with which a circumferential speed at the tool of the power tool can be kept essentially constant, while a rotational speed spread DELTA_n of greater than 2 is achieved by the design, dimensioning and/or control of the motor. Also provided is a tool device, for example a core drilling device, with which the proposed method can be carried out. An essential advantage of the invention is that the rotational speed spread DELTA_n of greater than 2 is achieved without a mechanical transmission on the power tool. Instead, a rotational speed graduation of an electronic form is used in the present invention.

Abstract: In a control method for a hand-held power tool, a striking mechanism is driven with an electric motor, wherein an exciter piston of the pneumatic striking mechanism is driven periodically by the electric motor and a striking piston of the striking mechanism is coupled to the exciter piston via a pneumatic chamber. The method includes detecting the acceleration of a machine housing along a striking direction of the striking piston in different phases of the movement of the exciter piston; and controlling a rotational speed of an electric motor according to the detected acceleration in the different phases.

Abstract: Power tool, in particular a hammer drill, including a housing, a tool fitting for receiving and holding a tool, an impact device for producing and transmitting impact pulses to the tool, and a rotation device for producing and transmitting a torque to the tool, wherein a working axis passing through the impact device is provided. The power tool includes a first drive unit having a first axis of rotation for driving the rotation device and a second drive unit having a second axis of rotation for driving the impact device, wherein the first and second drive units are arranged in such a way relative to one another in the housing that the first axis of rotation of the first drive unit is arranged at a first angle to the second axis of rotation of the second drive unit and at a second angle to the working axis.

Abstract: A control method for a hand-held power tool comprises: of driving a striking mechanism with an electric motor, wherein an exciter piston of the pneumatic striking mechanism is driven periodically by the electric motor and a striking piston of the striking mechanism is coupled to the exciter piston via a pneumatic chamber, detecting the acceleration of a machine housing along a striking direction of the striking piston in different phases of the movement of the exciter piston; and controlling a rotational speed of an electric motor according to the detected acceleration in the different phases.

Abstract: A method for operating a hand-guided machine tool. The method contains detecting at least one linear acceleration value by means of the at least one sensor apparatus (6); subtracting the gravitational acceleration from the at least one linear acceleration value to form an adjusted linear acceleration value; integrating the adjusted linear acceleration value into a speed value; integrating the speed value into a distance value; multiplying the speed value by a time constant to form at least one further distance value; adding the distance value to the further distance value to form at least one total distance value; filtering at least one of the linear acceleration values and/or at least one of the speed values; comparing the total distance value with a defined limit value; and initiating a predefined action when the total distance value exceeds the defined limit value. A hand-held machine tool for carrying out such a method is also described.

Abstract: A handheld power tool includes a tool holder for holding a tool, an electric motor, a shaft connecting the tool holder and the electric motor, and a protective device for stopping the tool holder in an uncontrolled situation. The protective device includes a sensor for detecting the uncontrolled situation, a switchable current source and a normally closing magnetic brake. The switchable current source outputs a first current not equal to zero in response to signals of the sensor if an uncontrolled situation is not detected; the current source does not output a current or outputs a second current different from the first current if an uncontrolled situation is detected. The normally closing magnetic brake engages on the shaft and does not apply a torque to the shaft when energized by the first current. The normally closing magnetic brake applies a torque counteracting the rotational movement of the shaft when not energized or when energized by the second current.

Abstract: A control method is provided for a hand-held power tool (1), which includes a motor (5) for rotationally driving a tool holder (2) about a working axis (12), including the following steps: detecting a rotary motion of the hand-held power tool (1) about the working axis (12); detecting a rotary or pivoting motion about a transverse axis (18) extending transversely to the working axis (12); triggering a safety function for reducing the torque output of the motor (5) when the rotary motion about the working axis (12) exceeds a limiting value, and suppressing the safety function when the rotary or pivoting motion about the transverse axis (18) is greater than a threshold value.

Abstract: A handheld power tool includes a tool holder for holding a tool, an electric motor, a shaft connecting the tool holder and the electric motor, and a protective device for stopping the tool holder in an uncontrolled situation. The protective device includes a sensor for detecting the uncontrolled situation, a switchable current source and a normally closing magnetic brake. The switchable current source outputs a first current not equal to zero in response to signals of the sensor if an uncontrolled situation is not detected; the current source does not output a current or outputs a second current different from the first current if an uncontrolled situation is detected. The normally closing magnetic brake engages on the shaft and does not apply a torque to the shaft when energized by the first current. The normally closing magnetic brake applies a torque counteracting the rotational movement of the shaft when not energized or when energized by the second current.

Abstract: A machine tool is disclosed. A magneto-pneumatic striking mechanism has a primary actuator arranged around an axis of movement and includes a first magnetic coil and a second magnetic coil. The striking mechanism has, on the axis of movement within the magnetic coils, a striker and a die. Furthermore, the striking mechanism has an air spring acting on the striker in a direction of impact. The air spring may be entirely or partially within the first magnetic coil. The air spring has a ventilation opening that is open to the environment if the striker is less than 10% of its stroke away from the die, and otherwise the ventilation opening is closed. An exchange of air with the environment is therefore only possible when the striker is near the die or is near the impact position.

Abstract: A control method for a power tool for rotary tools provides the following: A tool holder is rotated continuously in a forward direction about a working axis by a rotary drive when an operating switch is actuated. The continuous rotation in the forward direction is interrupted by a protective process when a protective device senses blocking of the tool holder. During the protective process, one or more cycles are executed, in which the rotary drive is actuated successively in accordance with an unimpeded rotary movement in a reverse direction and in accordance with an unimpeded rotary movement in the forward direction. The rotary drive is supplied with a first amount of energy for the rotary movement in the reverse direction and with a second amount of energy for the rotary movement in the forward direction. The first amount of energy is smaller than the second amount of energy.

Abstract: A control method is provided for a hand-held power tool (1), which includes a motor (5) for rotationally driving a tool holder (2) about a working axis (12), including the following steps: detecting a rotary motion of the hand-held power tool (1) about the working axis (12); detecting a rotary or pivoting motion about a transverse axis (18) extending transversely to the working axis (12); triggering a safety function for reducing the torque output of the motor (5) when the rotary motion about the working axis (12) exceeds a limiting value, and suppressing the safety function when the rotary or pivoting motion about the transverse axis (18) is greater than a threshold value.

Abstract: A percussion mechanism includes a first shaft and a second shaft. One or more vanes are fastened to the first shaft. The vanes are arranged so as to be rotatable in a chamber of the second shaft. The chamber is filled with a magnetorheological fluid. A magnetic field source on the second shaft generates a magnetic field that is spatially modulated in the circumferential direction inside the chamber.

Abstract: A hand-held power tool has a motor, a tool holder, and a percussion mechanism disposed between the motor and the tool holder in the drive train. The percussion mechanism includes a first shaft and a second shaft. A magnetically conductive ring gear is connected to the first shaft. An inner wall of the ring gear is eccentric to an axis of the second shaft. A magnetically conductive impeller is connected to the second shaft and is arranged to rotate within the ring gear. The impeller is spaced from the ring gear by a first air gap in a first position while being spaced from the ring gear by a second air gap in a second position, the first air gap being smaller than the second one. A magnet array is arranged coaxially to the second shaft. A magnetorheological fluid fills a cavity between the ring gear and the impeller.

Abstract: A handheld power tool is disclosed. The handheld power tool has a drive oscillating along a working axis and a vibration damper. The vibration damper has a mass element suspended in a spring mechanism. The spring mechanism acts with a first spring stiffness and acts with a second spring stiffness. The first spring stiffness is different from the second spring stiffness.

Abstract: A hand-held power tool has a motor, a tool holder, and a percussion mechanism disposed between the motor and the tool holder in the drive train. The percussion mechanism includes a first shaft and a second shaft. A magnetically conductive ring gear is connected to the first shaft. An inner wall of the ring gear is eccentric to an axis of the second shaft. A magnetically conductive impeller is connected to the second shaft and is arranged to rotate within the ring gear. The impeller is spaced from the ring gear by a first air gap in a first position while being spaced from the ring gear by a second air gap in a second position, the first air gap being smaller than the second one. A magnet array is arranged coaxially to the second shaft. A magnetorheological fluid fills a cavity between the ring gear and the impeller.

Abstract: A percussion mechanism includes a first shaft and a second shaft. One or more vanes are fastened to the first shaft. The vanes are arranged so as to be rotatable in a chamber of the second shaft. The chamber is filled with a magnetorheological fluid. A magnetic field source on the second shaft generates a magnetic field that is spatially modulated in the circumferential direction inside the chamber.

Abstract: A machine tool with a tool holder which is equipped to mount a tool, such as a chiseling tool, moveably along a movement axis. A striking mechanism contains a primary drive, arranged around the movement axis, containing at least one magnetic coil. The striking mechanism has a striker and an anvil arranged within the magnetic coil on the movement axis in sequence in the impact direction. The anvil protrudes at least partially into the magnetic coil. In addition, the striking mechanism can have an air spring affecting the striker in the impact direction. A controlled power source forms an electrical circuit in which a current flows, controlled at a target value, from the power source and into at the at least one magnetic coil during an acceleration phase. A controller ends the acceleration phase when a change, typical for an impact, is detected in the current flowing in the magnetic coil or a change, typical for an impact, is detected in a control variable of a control circuit of the power source.

Abstract: A machine tool is disclosed. A magneto-pneumatic striking mechanism has a primary actuator arranged around an axis of movement and includes a first magnetic coil and a second magnetic coil. The striking mechanism has, on the axis of movement within the magnetic coils, a striker and a die. Furthermore, the striking mechanism has an air spring acting on the striker in a direction of impact. The air spring may be entirely or partially within the first magnetic coil. The air spring has a ventilation opening that is open to the environment if the striker is less than 10% of its stroke away from the die, and otherwise the ventilation opening is closed. An exchange of air with the environment is therefore only possible when the striker is near the die or is near the impact position.

Abstract: A hand-operated rotary power tool and a method of operating the tool is disclosed. The tool has an electric motor for driving a rotary tool, a sensor device for detecting a blockade of the tool and a triggering device, which, in response to a blockade detected by the sensor device, reverses a direction of rotation of the electric motor prior to the blockade for a predetermined duration and immediately following induces the electric motor to again rotate in the direction of rotation.

Abstract: A handheld power tool is disclosed. The handheld power tool has a drive oscillating along a working axis and a vibration damper. The vibration damper has a mass element suspended in a spring mechanism. The spring mechanism acts with a first spring stiffness and acts with a second spring stiffness. The first spring stiffness is different from the second spring stiffness.