A control method for a power tool for rotary tools comprises rotating a tool holder continuously about a working axis by a rotary drive. A rotary movement of a handle about the working axis is sensed by a motion sensor. A first angle of rotation of the handle is estimated by a first motion estimator, wherein rotary movements beneath a limit value are discounted. A second angle of rotation of the handle is estimated by a second motion estimator, wherein rotary movements beneath the limit value are taken into account. A measure for reducing the torque output of the rotary drive is activated when the first angle of rotation exceeds a first triggering threshold (A1), and when the second angle of rotation exceeds a second triggering threshold (A2) and at the same time a power output of the rotary drive exceeds a power threshold (L).

A control method for a power tool for rotary tools comprises rotating a tool holder continuously about a working axis by a rotary drive. A rotary movement of a handle about the working axis is sensed by a motion sensor. A first angle of rotation of the handle is estimated by a first motion estimator, wherein rotary movements beneath a limit value are discounted. A second angle of rotation of the handle is estimated by a second motion estimator, wherein rotary movements beneath the limit value are taken into account. A measure for reducing the torque output of the rotary drive is activated when the first angle of rotation exceeds a first triggering threshold (A1), and when the second angle of rotation exceeds a second triggering threshold (A2) and at the same time a power output of the rotary drive exceeds a power threshold (L).

There are provided a load state diagnosis device and a load state diagnosis method for a servomotor. A PLC diagnoses the load state of the servomotor which rotationally drives a rotary tool in a predetermined rotational drive direction at a constant speed. The PLC includes a detection part that detects the rotational direction of a torque acting on the servomotor, a determination part that determines whether the rotational direction of the torque detected by the detection part is consistent with the predetermined rotational drive direction, and a load index output part that outputs a load index indicating the load state of the servomotor based on a determination result of the determination part.

There are provided a load state diagnosis device and a load state diagnosis method for a servomotor. A PLC diagnoses the load state of the servomotor which rotationally drives a rotary tool in a predetermined rotational drive direction at a constant speed. The PLC includes a detection part that detects the rotational direction of a torque acting on the servomotor, a determination part that determines whether the rotational direction of the torque detected by the detection part is consistent with the predetermined rotational drive direction, and a load index output part that outputs a load index indicating the load state of the servomotor based on a determination result of the determination part.

A power tool has a housing, a motor disposed within the housing, a power supply circuit for providing power to the motor, a controller circuit for controlling the power provided to the motor, and an electric static discharge (ESD) protection circuit connected to the power supply circuit and the housing. The ESD protection circuit includes a first resistor connected to the power supply circuit and the housing. The first resistor may be a high impedance resistor. The ESD protection circuit may also have a first capacitor connected in parallel to the first resistor, a second resistor connected in series to the first resistor, and a second capacitor connected in series to the first capacitor and in parallel to the second resistor.

A power tool has a housing, a motor disposed within the housing, a power supply circuit for providing power to the motor, a controller circuit for controlling the power provided to the motor, and an electric static discharge (ESD) protection circuit connected to the power supply circuit and the housing. The ESD protection circuit includes a first resistor connected to the power supply circuit and the housing. The first resistor may be a high impedance resistor. The ESD protection circuit may also have a first capacitor connected in parallel to the first resistor, a second resistor connected in series to the first resistor, and a second capacitor connected in series to the first capacitor and in parallel to the second resistor.

An apparatus includes a spindle, a pecking mechanism, and a clutch mechanism coupled to the pecking mechanism. The spindle includes a drill tool and the spindle is configured to be fed in a first direction during a drilling operation. The pecking mechanism is configured to retract the drill periodically during the drilling operation. The clutch mechanism is configured to selectively engage the pecking mechanism during a portion of the drilling operation. The clutch mechanism is configured to constrain the rotation of the washer such that the spindle drill is retracted a predefined distance periodically.

A power tool includes a motor, a power circuit coupled to the motor, and a speed sensor coupled to the motor. The power circuit provides power to the motor. The speed sensor detects a position of the motor. The power tool also includes an electronic processor coupled to the motor and the speed sensor. The electronic processor is configured to receive an output signal from the speed sensor indicative of a measured speed of the motor at a first time, determine a cumulative value based on the measured speed of the motor, and interrupt power from the power circuit to the motor when the cumulative value exceeds an accumulator threshold.

The control method for a hammer drill (1) provides the following steps. During basic operation, the motor (5) rotates at an operating speed for the drilling operation with chiseling action in order to rotationally drive the tool holder (2) and to drive the hammer mechanism (6) with a nominal striking power. The torque coupling (21) is monitored with the aid of a sensor (26). If a disengagement of the torque coupling (21) occurs, the striking power of the hammer mechanism (6) is reduced to below 10% of the nominal striking power during a disengagement of the torque coupling (21), and the torque coupling (21) is driven. When the disengagement of the torque coupling (21) ends, the striking power of the hammer mechanism (6) is increased to the nominal striking power and the torque coupling (21) is driven at the operating speed for the drilling operation with chiseling action.

There are provided a load state diagnosis device and a load state diagnosis method for a servomotor. A PLC diagnoses the load state of the servomotor which rotationally drives a rotary tool in a predetermined rotational drive direction at a constant speed. The PLC includes a detection part that detects the rotational direction of a torque acting on the servomotor, a determination part that determines whether the rotational direction of the torque detected by the detection part is consistent with the predetermined rotational drive direction, and a load index output part that outputs a load index indicating the load state of the servomotor based on a determination result of the determination part.