Abstract: An impact wrench includes a driving unit, a spindle configured to be rotated by the driving unit, an anvil arranged in front of the spindle in a direction of a rotational axis of the spindle, a primary hammer that is capable of rotating about the rotational axis of the spindle and moving in the direction of the rotational axis of the spindle, a secondary hammer having a cylindrical part in which the primary hammer is housed and that rotates synchronously with the primary hammer, the cylindrical part being configured to receive the spindle, and a rotary impact mechanism that impulsively engages the primary hammer with the anvil to rotate the anvil about the rotational axis of the spindle.

Abstract: An electric power tool is included in a plurality of types of electric power tools. The plurality of types of electric power tools comprise a plurality of types of battery packs having different rated output voltages and a plurality of types of tool bodies, the housings of which are equipped with an attached part on which each of the battery packs is mounted in a freely removable manner. The attached part possessed by the plurality of types of tool bodies equipped with motors having different voltage characteristics is formed so as to be able to mount an arbitrary one of the plurality of types of battery packs having different rated output voltages. This makes it possible to widen the range of available battery packs and enhance convenience.

Abstract: To improve the durability of a bearing mechanism such as a rolling bearing that is provided between a secondary hammer and a spindle in an impact wrench configured to firmly tighten screws by applying an impact in the rotational direction of an anvil, using a primary hammer and the secondary hammer, a technique is provided in which a rolling bearing is used as the bearing mechanism, the inner circumference of the secondary hammer is press-fitted to an outer ring of the rolling bearing, and a gap is created between the outer circumference of a spindle and an inner ring of the rolling bearing. The created gap can exhibit the effect of cushioning precession rotation of the secondary hammer to reduce the radial load that is applied to the rolling bearing, and, as a result, improve the durability of the rolling bearing and extend the life of the bearing.

Abstract: An installation structure of a temperature sensor in a brush motor includes a holding plate; a metal-made fixing base; and a brush holder arranged on the fixing base to hold a brush in place. The metal-made fixing base is provided on the holding plate, and the fixing base includes a sensor attachment portion to which the temperature sensor is attached. Further, the sensor attachment portion is positioned outside the holding plate.

Abstract: A changeover operation device, for changing over the positions of at least two components to establish three or more speed modes in a speed changer mechanism accommodated within a housing having an opening, includes operation handles arranged in a corresponding relationship with the components. Each of the operation handles is movable between two specified positions along a specified operation direction to change over the positions of the components. The operation handles are continuously arranged within the opening of the housing, one of the operation handles being partially overlapped with the other.

Abstract: An electric power tool is included in a plurality of types of electric power tools. The plurality of types of electric power tools comprise a plurality of types of battery packs having different rated output voltages and a plurality of types of tool bodies, the housings of which are equipped with an attached part on which each of the battery packs is mounted in a freely removable manner. The attached part possessed by the plurality of types of tool bodies equipped with motors having different voltage characteristics is formed so as to be able to mount an arbitrary one of the plurality of types of battery packs having different rated output voltages. This makes it possible to widen the range of available battery packs and enhance convenience.

Abstract: An installation structure of a temperature sensor in a brush motor includes a holding plate; a metal-made fixing base; and a brush holder arranged on the fixing base to hold a brush in place. The metal-made fixing base is provided on the holding plate, and the fixing base includes a sensor attachment portion to which the temperature sensor is attached. Further, the sensor attachment portion is positioned outside the holding plate.

Abstract: A power tool system with enhanced antitheft capability has a hand-held power tool and a wearable piece worn by the user. The wearable piece incorporates a certification unit which stores an identification code specifying the power tool and transmits the identification code to an authenticator incorporated in the power tool. The authenticator reads the identification code from the certification unit and to provide an authentication signal when the identification code is authenticated to be eligible for a privileged use of the power tool. The power tool is enabled only in response to the authentication signal, and otherwise disabled for avoiding unauthorized use. A communication is established between the certification unit and the authenticator for transmission of the identification code, while the user holds the power tool with the wearable piece carried on.

Abstract: A changeover operation device, for changing over the positions of at least two components to establish three or more speed modes in a speed changer mechanism accommodated within a housing having an opening, includes operation handles arranged in a corresponding relationship with the components. Each of the operation handles is movable between two specified positions along a specified operation direction to change over the positions of the components. The operation handles are continuously arranged within the opening of the housing, one of the operation handles being partially overlapped with the other.

Abstract: A power tool includes a driving unit for performing screw tightening operations; a motor for rotatably driving the driving unit; a trigger switch for turning on and off the motor; and a control circuit, accommodated in a main body of the power tool, for monitoring the screw tightening operations. The control circuit having a screw tightening completion detection unit for detecting completion of a screw tightening operation, a screw tightening count unit for counting the number of detected tightening operations, a screw tightening number setting unit for presetting the number of screws to be tightened, a screw tightening completion notifying unit for notifying completion of the screw tightening operations when the number of detected tightening operations reaches the preset number of screws.

Abstract: A power tool includes a driving unit for performing screw tightening operations; a motor for rotatably driving the driving unit; a rechargeable battery pack; a trigger switch for turning on and off the motor; and a control circuit, accommodated in a main body of the power tool, for monitoring the screw tightening operations. The control circuit has a screw tightening completion detection unit for detecting completion of a screw tightening operation, a screw tightening count unit for counting the number of detected tightening operations, a screw tightening number setting unit for presetting the number of screws to be tightened, a screw tightening completion notifying unit for notifying completion of the screw tightening operations when the number of detected tightening operations reaches the preset number. Further, the screw tightening number setting unit and the screw tightening completion notifying unit is disposed at a lower front portion of a grip portion.

Abstract: A power tool includes a driving unit for performing screw tightening operations; a motor for rotatably driving the driving unit; a rechargeable battery pack; a trigger switch for turning on and off the motor; and a control circuit, accommodated in a main body of the power tool, for monitoring the screw tightening operations. The control circuit has a screw tightening completion detection unit for detecting completion of a screw tightening operation, a screw tightening count unit for counting the number of detected tightening operations, a screw tightening number setting unit for presetting the number of screws to be tightened, a screw tightening completion notifying unit for notifying completion of the screw tightening operations when the number of detected tightening operations reaches the preset number. Further, the screw tightening number setting unit and the screw tightening completion notifying unit is disposed at a lower front portion of a grip portion.

Abstract: A power tool includes a driving unit for performing screw tightening operations; a motor for rotatably driving the driving unit; a trigger switch for turning on and off the motor; and a control circuit, accommodated in a main body of the power tool, for monitoring the screw tightening operations. The control circuit having a screw tightening completion detection unit for detecting completion of a screw tightening operation, a screw tightening count unit for counting the number of detected tightening operations, a screw tightening number setting unit for presetting the number of screws to be tightened, a screw tightening completion notifying unit for notifying completion of the screw tightening operations when the number of detected tightening operations reaches the preset number of screws.

Abstract: An electric power tool includes a motor; a battery unit for supplying an electric power for driving the motor; a driving force transmission mechanism for transmitting a driving force of the motor; a manipulation unit for receiving input data including a rotation number and an on/off manipulation of the motor; a motor control unit for controlling the motor based on the input data from the manipulation unit; and a temperature sensor for detecting a temperature of the battery unit as a temperature value. If the temperature value detected by the temperature sensor while being operated in an normal operation mode is higher than or equal to a first abnormal temperature value, the motor control unit determines that the battery unit is in an abnormal state, and converts an operation mode of the motor to a limited operation mode in which a rotation of the motor is stopped or suppressed.

Abstract: A power tool system with enhanced antitheft capability has a hand-held power tool and a wearable piece worn by the user. The wearable piece incorporates a certification unit which stores an identification code specifying the power tool and transmits the identification code to an authenticator incorporated in the power tool. The authenticator reads the identification code from the certification unit and to provide an authentication signal when the identification code is authenticated to be eligible for a privileged use of the power tool. The power tool is enabled only in response to the authentication signal, and otherwise disabled for avoiding unauthorized use. A communication is established between the certification unit and the authenticator for transmission of the identification code, while the user holds the power tool with the wearable piece carried on.

Abstract: An impact rotary tool includes an output shaft having an anvil at an end portion thereof, a hammer having a projecting portion applying an impact force to the anvil under a predetermined condition, a driving shaft connected to the hammer through a cam mechanism, and a changeover mechanism for changing the connection between the driving shaft and the output shaft. The mechanism is arranged along with a common axis defined by the driving shaft and the output shaft. The changeover mechanism includes a connecting member accommodated into the driving shaft in a first condition, and connecting the driving shaft and the output shaft in a second condition.