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 power tool having a tool and a motor, with the motor of the power tool being operated in a speed range from 2,000 to 30,000 rpm and with an inertia of the motor lying in a range from 20·10?6 to 750·10?6 kg·m2. In a second aspect, the invention relates to a method for operating a power tool which is operated in a speed range from 2,000 to 30,000 rpm, with an inertia of the motor lying in a range from 20·10?6 to 750·10?6 kg·m2. By selecting and specifying a set of parameters which describe characteristics of the motor of the power tool, the power tool can be designed and operated in such a way that a mechanical slip clutch can be dispensed with. The motor parameters “speed” and “inertia” are selected in particular so that a maximum torque in a transmission of the power tool is always below a specified upper limit.

Abstract: Methods for counterbalancing a weight force of an object fastenable to a traction cable. A system is configured to carry out a counterbalancing operation with respect to the weight force of the object. This counterbalancing operation can be performed in that a rotational speed of the motor and/or a derivation of the rotational speed of the motor is determined, wherein a current setpoint value can be stored as a controlled variable in the system. The rotational speed of the motor or a derivation thereof corresponds to a weight force of the object. Alternatively, a current value required for maintaining the first position of the object or a motor torque required for this purpose can be stored in the system and the weight force of the object can be counterbalanced using the previously stored current values or torques. In further aspects, the invention relates to a system and to an electronic module.

Abstract: A system for counterbalancing a weight force of an object is provided. The object is fastenable to a traction cable, wherein the traction cable is guided in or on a cantilever in the direction of a back structure of the system, wherein a second end of the cantilever can be accommodated by a back structure, and the system can be carried by a user of the system via the back structure. The system is characterized by an electronic module which includes an apparatus for winding up the traction cable and a motor for driving the apparatus for winding up the traction cable, wherein the system is configured to determine a counterforce for the weight force of the object and to transmit same to the object. It is particularly preferred for the purposes of the invention that a control device of the system is configured to adjust a counterforce with respect to the weight force of the object.

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.