An electric power tool in one aspect of the present disclosure includes a motor, an impact mechanism, and a control circuit. The control circuit executes a motor control process. The motor control process includes limiting an output of the motor in response to establishment of a preset condition. The preset condition is based on a load applied to the motor.

A method for controlling or regulating a hand-held power tool, in particular a screwdriver, preferably a rotary impact screwdriver. The method includes: application of a first torque, in particular torque impulse, to a screw in a first direction of rotation, and application of a second torque, in particular torque impulse, to the screw, in a second direction of rotation opposite to the first direction of rotation.

A rotating power tool is provided. The rotating power tool may include a bevel gear set having a bevel gear and a conductive spiral disposed on the bevel gear. The conductive spiral may be configured to, in response to the bevel gear deforming due to a torque being applied to the bevel gear, change a resistance of the conductive spiral. The rotating power tool may further include an antenna electrically connected to the conductive spiral. The antenna may be configured to emit an output signal at a frequency that is based on the resistance value of the conductive spiral. The frequency of the output signal may be indicative of an amount of torque being applied to the bevel gear.

A signal processing apparatus for an electric tool is provided for generating a motor control signal for controlling a motor by performing a smoothing process on a torque value signal from a torque sensor of an electric tool by using a filter. The signal processing apparatus includes a half width detector circuit that detects a half width of the torque value signal; and a calculator circuit that controls a cut-off frequency of the filter to change the cut-off frequency according to a number of hits of the electric tool, based on the detected half width of the torque value signal.

Methods and associated system for calibrating a torque device are provided. The method includes (I) providing a master torque tool having an accepted calibration, (II) attaching the torque device to be calibrated to an input shaft of a testing and calibration system, (III) energizing the torque device to a free spin under a no load and zero torque condition, (IV) performing a run down test by activating a torque engagement mechanism to transferred torque from the torque device to the master torque tool, (V) measuring a torque value from the master torque tool, the torque device, and the rotary inline torque transducer to generate a data set, (IX) repeating steps (IV) to generate a plurality of data sets and (V), and (VI) generating new calibration factors for input into a programmable control system of the torque device based on the plurality of data sets with a software package.

An impact tool includes a motor, an output block, a hammer, and a magnetostrictive sensor. The magnetostrictive sensor includes a magnetostrictive member and a coil portion covering the magnetostrictive member. The output block includes a claw block and a body block. The claw block includes an anvil claw, against which a hammer claw collides. The claw block has been subjected to quenching treatment. The body block includes a thermally sprayed portion and is coupled to the claw block. The thermally sprayed portion includes, on a surface thereof, the magnetostrictive member made of a magnetostrictive material.

A programmable screw driver and method for affixing screws into bone is disclosed. The screw driver includes a torque sensor for measuring torsional input during screw insertion, a rotational motion sensor for measuring the rotation of the screw driver, and a microprocessor. Once a surgeon rotates a screw to be affixed to the bone, the torque sensor measures the torque and sends this information to the microprocessor. Once a predetermined torque level is attained, the microprocessor begins to measure subsequent rotation of the screw driver until a predetermined rotational limit, thereby causing a signal to be sent to alert the surgeon to stop tightening.

An electric power tool includes: a driving shaft that is rotated by a motor; an output shaft on which a front-end tool is attachable; and a torque transmission mechanism that transmits a torque produced by the rotation of the driving shaft to the output shaft. The torque transmission mechanism includes a magnet coupling including a driving magnet member coupled to a side of the driving shaft and a driven magnet member coupled to a side of the output shaft, and the driving magnet member and the driven magnet member are provided such that respective magnetic surfaces face each other, S-poles and N-poles being alternately arranged on each of the magnetic surfaces.

A signal processing apparatus for a tool including a rotating body rotated by impacts delivered from a drive apparatus is provided with: a filter a calculation circuit and a control circuit. The filter receives a torque value signal indicating a torque applied to the rotating body, and filters the torque value signal. The calculation circuit sets a filter coefficient of the filter based on a number of impacts delivered to the rotating body. The control circuit controls the impacts delivered to the rotating body, based on the torque value signal filtered by the filter.

A method for controlling or regulating a hand-held power tool, in particular a screwdriver, preferably a rotary impact screwdriver. The method includes: application of a first torque, in particular torque impulse, to a screw in a first direction of rotation, and application of a second torque, in particular torque impulse, to the screw, in a second direction of rotation opposite to the first direction of rotation.