Abstract: An electric fastener driver having a compact size and simple construction. A driver segment provided with a rack is movably disposed in a housing. A flywheel is driven by a motor. A drive shaft is concentric with and integral with the flywheel. A coil spring is fixed to the drive shaft. A driven rotor is coaxial with the drive shaft and has one end portion serving as a spring seat portion positioned within the coil spring. A pinion is disposed at the driven rotor and is meshedly engaged with the rack. An urging section is disposed within the driven rotor. A ball is movably disposed in a through-hole formed in the driven rotor for urging an end portion of the coil spring by the urging section. A solenoid controls a protruding amount of the ball from the surface of the driven rotor.

Abstract: A cover which covers outer peripheries of fastening screws are disposed on an outer periphery of a hammer case. A stopper which detachably positions and fixes the cover to the outer periphery of the hammer case is disposed.

Abstract: A cover which covers outer peripheries of fastening screws are disposed on an outer periphery of a hammer case. A stopper which detachably positions and fixes the cover to the outer periphery of the hammer case is disposed.

Abstract: In order to prevent a battery pack from being overly discharged during use in a power tool, a discharge voltage limit circuit is provided. The circuit disconnects the battery pack from the motor when the voltage of the battery pack falls below a predetermined level. However, the circuit is operable only when the main switch is OFF, that is, when no load is imposed on the motor.

Abstract: When a battery pack having an output voltage of 14.4 V that is connectable to an electric tool in a sliding manner is used as a power supply source for the electric tool that is connectable to a battery pack in an insertion manner and has a rated voltage of 12 V, the electric tool and the battery pack are connected to each other with an adaptor interposed therebetween. The adaptor has an FET that is switched at a predetermined duty of a predetermined frequency. The battery pack and the electric tool are connected or disconnected to or from each other by the switching operation, thereby dropping the output voltage of the battery pack. The voltage from the battery pack is detected. When the detected voltage is out of a predetermined value range, it is judged that the overcurrent or overdischarge has occurred. Then, the FET is turned off to stop the electric tool.

Abstract: A commutator motor includes a stator and a rotor, and the stator includes a stator yoke and a field magnet. The field magnet is fixed onto the inner peripheral surface of the substantially cylindrical stator yoke. The stator yoke is configured by coaxially stacking a plurality of plate-like annular bodies, and the annular bodies are fixedly connected to each other by caulking at a caulking portion disposed on the annular body. In manufacture, the length of the stator yoke in the axial direction can be arbitrarily changed with the thickness of the annular body in the axial direction as a minimum unit. In case of manufacturing various stator yokes that are different in the axial length, the necessity of replacing a manufacturing machine is eliminated, thereby providing a commutator motor having the stator yoke which is low in the manufacturing costs.

Abstract: A power tool includes a hook portion having a hook holding portion, which is provided in a housing and has engaging teeth provided in the housing. A hook having a shaft portion is inserted into the hook holding portion and provided with fitting teeth meshing with the engaging teeth An elastic body is adapted to push the hook against a handle portion at all times, and a slip-off preventing part holding portion is adapted to move the hook in a direction of an axis thereof against a force of the elastic body and to cancel the mesh between the teeth to thereby enable the hook to turn.

Abstract: An electric fastener driver having a compact size and simple construction. A driver segment provided with a rack is movably disposed in a housing. A flywheel is driven by a motor. A drive shaft is concentric with and integral with the flywheel. A coil spring is fixed to the drive shaft. A driven rotor is coaxial with the drive shaft and has one end portion serving as a spring seat portion positioned within the coil spring. A pinion is disposed at the driven rotor and is meshedly engaged with the rack. An urging section is disposed within the driven rotor. A ball is movably disposed in a through-hole formed in the driven rotor for urging an end portion of the coil spring by the urging section. A solenoid controls a protruding amount of the ball from the surface of the driven rotor.

Abstract: A cover which covers outer peripheries of fastening screws are disposed on an outer periphery of a hammer case. A stopper which detachably positions and fixes the cover to the outer periphery of the hammer case is disposed.

Abstract: A power tool includes an impact damping mechanism for damping an impact in a direction of rotation of a speed reduction mechanism portion 8.

Abstract: A commutator motor includes a stator and a rotor, and the stator includes a stator yoke and a field magnet. The field magnet is fixed onto the inner peripheral surface of the substantially cylindrical stator yoke. The stator yoke is configured by coaxially stacking a plurality of plate-like annular bodies, and the annular bodies are fixedly connected to each other by caulking at a caulking portion disposed on the annular body. In manufacture, the length of the stator yoke in the axial direction can be arbitrarily changed with the thickness of the annular body in the axial direction as a minimum unit. In case of manufacturing various stator yokes that are different in the axial length, the necessity of replacing a manufacturing machine is eliminated, thereby providing a commutator motor having the stator yoke which is low in the manufacturing costs.

Abstract: A power tool includes a hook portion having a hook holding portion, which is provided in a housing and has engaging teeth provided in the housing. A hook having a shaft portion is inserted into the hook holding portion and provided with fitting teeth meshing with the engaging teeth An elastic body is adapted to push the hook against a handle portion at all times, and a slip-off preventing part holding portion is adapted to move the hook in a direction of an axis thereof against a force of the elastic body and to cancel the mesh between the teeth to thereby enable the hook to turn.

Abstract: In a motor-driven tool, a carbon brush part 8 is arranged between a suction port 6 and a commutator 11 of the motor and includes a cylindrical side wall 8a. The cylindrical side wall 8a located on an outer periphery of the commutator 11 is provided with a tapered portion 8b which grows wider toward the commutator 11 and grows narrower toward a coil end 10 of the armature. Between the carbon brush part 8 and the coil end 10, there is provided a heat radiating plate 4 made of metal and adapted to be engaged with the carbon brush part 8.

Abstract: A power tool includes a motor as a drive power source, a body housing the motor and having an end output unit for chucking an end tool, a handle grip connected to the body; and a light unit disposed to one of the handle grip and the body, and having a light-emitting element for providing illumination near the end tool. The light unit comprises switch means for switching the light-emitting element on and off, and an off circuit for automatically turning the light-emitting element off at a predetermined time after the light-emitting element turns on.

Abstract: A commutator motor includes a stator and a rotor, and the stator includes a stator yoke and a field magnet. The field magnet is fixed onto the inner peripheral surface of the substantially cylindrical stator yoke. The stator yoke is configured by coaxially stacking a plurality of plate-like annular bodies, and the annular bodies are fixedly connected to each other by caulking at a caulking portion disposed on the annular body. In manufacture, the length of the stator yoke in the axial direction can be arbitrarily changed with the thickness of the annular body in the axial direction as a minimum unit. In case of manufacturing various stator yokes that are different in the axial length, the necessity of replacing a manufacturing machine is eliminated, thereby providing a commutator motor having the stator yoke which is low in the manufacturing costs.

Abstract: A pulse torque generator utilizing a magnetic coupling, and an electric power tool provided with the pulse torque generator. The pulse torque generator includes an input shaft extending in its axial direction and having a hollow section providing a hollow space, and an output shaft rotatably provided in the hollow space. A magnetic fluid is encapsulated in a hollow space between the input shaft and output shaft. A magnetic field generating unit is disposed, and magnetic segments are provided in the input shaft. A magnetic fluid provides a magnetic fluid bridge bridging between the input shaft and the output shaft each time the magnetic segment is brought into confrontation with the magnetic field generating unit.

Abstract: A power tool includes a hook portion having a hook holding portion, which is provided in a housing and has engaging teeth provided in the housing. A hook having a shaft portion is inserted into the hook holding portion and provided with fitting teeth meshing with the engaging teeth An elastic body is adapted to push the hook against a handle portion at all times, and a slip-off preventing part holding portion is adapted to move the hook in a direction of an axis thereof against a force of the elastic body and to cancel the mesh between the teeth to thereby enable the hook to turn.

Abstract: A portable tool includes a motive power section, a mechanical section driven by the motive power section, and an outer frame covering at least the motive power section and the mechanical section. The outer frame has an outer peripheral surface on which a label is mountable and a front end, a cover made from a light transmissive material is removably disposed to the outer frame for protectingly covering the label. The portable tool further includes a front cap made from an elastic material, wherein the front cap is removably fitted to the front end and prevents the cover from being displaced relative to the outer frame.

Abstract: A power tool has a light unit provided at the bottom part of the handle grip. The light unit can be adjusted to change the lighting angle and can hold the desired lighting angle. The light unit thus disposed does not get in the way, the lighting angle of the light unit is variable and the emitted light does not shake, depletion of the power supply due to the light switch of the light unit being left on is prevented, shadows of the end tool are not easily produced by light from the light unit, lighting contrast is high, wiring failures and continuity faults in the light-emitting element do not occur easily, and a small, economical power tool can be provided. The light-emitting element of the light unit is a yellow LED. The light unit turns off automatically at a predetermined time after the light turns on.

Abstract: A commutator motor includes a stator and a rotor, and the stator includes a stator yoke and a field magnet. The field magnet is fixed onto the inner peripheral surface of the substantially cylindrical stator yoke. The stator yoke is configured by coaxially stacking a plurality of plate-like annular bodies, and the annular bodies are fixedly connected to each other by caulking at a caulking portion disposed on the annular body. In manufacture, the length of the stator yoke in the axial direction can be arbitrarily changed with the thickness of the annular body in the axial direction as a minimum unit. In case of manufacturing various stator yokes that are different in the axial length, the necessity of replacing a manufacturing machine is eliminated, thereby providing a commutator motor having the stator yoke which is low in the manufacturing costs.