A power tool (1) is provided, especially a hammer drill and/or a chiseling hammer drill, including a percussive mechanism (12) with a percussive element (13) to generate a percussive pulse onto a tool (1), the element being reversibly movable along a longitudinal axis (R) by a magnetic field in order to generate the percussive pulse, and including at least a first and a second coil device (1, 2) to generate the magnetic field. Each coil device (1, 2) has at least a first coil ring (3) with a first radius (R1) and a second coil ring (4) with a second radius (R2), whereby the first radius (R1) of the first coil ring (3) is greater than the second radius (R2) of the second coil ring (4), so that a space (S) is formed, at least in certain areas, between the at least first and second coil rings (3, 4), whereby a fluid (L), especially an air stream, that serves to cool the coil device (1, 2) can flow through the space.

A method for reducing vibrations in a percussion tool includes activating, using an electronic controller of the percussion tool, the motor of the percussion tool, determining, using the electronic controller, that the percussion tool is in a loaded condition, and operating, using the electronic controller, the motor in accordance with a predetermined profile in response to determining that the percussion tool is in the loaded condition. The method also includes determining, using the electronic controller, that the percussion tool is in a no-load condition and operating, using the electronic controller, the motor with reduced speed in response to determining that the percussion tool is in the no-load condition.

A percussion tool comprises a housing and an electric motor positioned within the housing. The percussion tool further comprises a battery pack supported by the housing for providing power to the motor. The battery pack includes a plurality of battery cells having a nominal voltage of up to 120 Volts. The percussion tool further comprises a percussion mechanism driven by the motor and including a striker supported for reciprocation in the housing. The percussion tool has a ratio of impact energy to mass that is greater than or equal to 2.5 Joules/kilogram.

An impact tool includes a tubular tool holder, a hammering mechanism, a resistor, and a biasing member. An impact element moves forward and rearward in conjunction with a piston. An intermediate element is housed movable back and forth between the impact element and a tip tool. The intermediate element abuts on a rear end of the tip tool to indirectly transmit a striking force from the impact element to the tip tool in a normal striking. The resistor is configured to abut on at least one of the intermediate element and the tip tool to apply a resistance to a front-rear movement of at least one of the intermediate element and the tip tool in a non-striking state. The biasing member disposed on the tool holder biases the resistor to a side of at least one of the intermediate element and the tip tool.

A percussion tool comprises a housing and an electric motor positioned within the housing. The motor has a nominal outer diameter of up to about 80 mm and is operable to output at least about 2760 W. The percussion tool further comprises a battery pack supported by the housing for providing power to the motor. The battery pack includes a plurality of battery cells having a nominal voltage of up to 80 Volts and a sustained operating discharge current of between about 40 A and about 60 A. The percussion tool further comprises a percussion mechanism driven by the motor and including a striker supported for reciprocation in the housing. The percussion tool has a ratio of impact energy to mass that is greater than or equal to 2.5 Joules/kilogram.

A percussion tool comprises a housing, an electric motor positioned within the housing, a percussion mechanism driven by the electric motor and including a striker supported for reciprocation in the housing, a battery pack removably coupled to the housing for providing power to the electric motor when coupled to the housing, and an electronic controller including an electronic processor and a memory. The electronic controller is coupled to the electric motor and configured to activate the motor and determine whether the percussion tool is in a loaded condition. In response to determining that the percussion tool is in the loaded condition, the electronic controller is configured to operate the motor in accordance with a predetermined profile and in response to determining that the percussion tool is in a no load condition, the electronic controller is configured to operate the motor at a no-load speed.

A method for reducing vibrations in a percussion tool includes activating, using an electronic controller of the percussion tool, the motor of the percussion tool, determining, using the electronic controller, that the percussion tool is in a loaded condition, and operating, using the electronic controller, the motor in accordance with a predetermined profile in response to determining that the percussion tool is in the loaded condition. The method also includes determining, using the electronic controller, that the percussion tool is in a no-load condition and operating, using the electronic controller, the motor with reduced speed in response to determining that the percussion tool is in the no-load condition.

A power tool is provided including a brushless motor having a stator defining a plurality of phases and a rotor. A power unit is provided including power switches operable to deliver power to the motor. A primary controller is interfaced with the power unit to output drive signals to drive the phases of the motor over a series of sectors of the rotor rotation. The primary controller measures a back-electromotive force voltage of the motor and transitions motor commutation from the present sector to the next sector based in relation to the back-EMF voltage. A second controller is provided to receive at least one of the drive signals, calculate a speed and/or direction of rotation of the motor from the drive signals, and take corrective action to cut off supply of power to the motor if it detects an overspeed condition or incorrect direction of rotation.

A power tool is provided including a brushless motor having a stator defining a plurality of phases, a rotor rotatable relative to the stator, and power terminals electrically connected to the phases of the motor. A power unit is provided including power switches. A control unit is interfaced with the power unit to output a drive signal to one or more of the motor switches to drive the phases of the motor over a series of sectors of the rotor rotation. The control unit is configured detect incorrect rotation of the rotor by applying a first series of voltage pulses to a present sector and a second series of voltage pulses to a previous sector, measuring motor currents associated with the first and second series of voltage pulses, and comparing corresponding motor current measurements to detect a transition from the present sector to the previous sector.

A power tool is provided including a brushless motor having a stator defining a plurality of phases and a rotor. A power unit is provided including power switches and a control unit outputs a drive signal to the motor switches to drive the phases of the motor using a trapezoidal control scheme over a series of sectors. The control unit sets a conduction band within which each phase is commutated to a baseline value that is greater than 120 degrees, sets at least one commutation transition point as a function of the set conduction band, and within each sector, monitors an open-phase voltage of the motor to detect a back electromotive force (back-EMF) voltage of the motor and control commutation of at least one phase based on the open-phase voltage of the motor in relation to the at least one commutation transition point.