Abstract: A lawn mower comprising: a power supply; a chassis for holding the power supply; a fixed shaft attached to the chassis; a rotary blade which is rotatably supported with respect to the fixed shaft; a transmitting portion which transmits rotation of the power supply to the rotary blade; and a fixed blade which is coaxially-arranged with the rotary blade, wherein a distance between the rotary blade and the fixed blade can be varied.

Abstract: The present invention provides a power tool that can be used at a position away from the external power source. The power tool includes a housing, a motor, an end tool, a battery pack, and an inverter. The housing has an upper side portion and a lower side portion. The motor is supported by the housing and driven by alternate-current power. The end tool is supported by the housing and rotatably driven by the motor. The battery pack outputs direct-current voltage. The inverter is disposed on the upper side portion and at a position higher than the motor and configured to convert the direct-current voltage outputted from the battery pack into alternate-current voltage and to supply the motor with alternate-current power.

Abstract: A charging signal Vi responding to a charging current is inputted to one input terminal (?) of an operational amplifier 95 forming a comparator and a setting signal Vr corresponding to a setting current value is inputted to the other input terminal (+) of the operational amplifier 95. When the charging signal Vi is not higher than the setting signal Vr, a charging stop signal is generated from the output terminal of the operational amplifier 95 to interrupt a switch unit 4. A starting signal Vcc larger than the setting signal Vr applied to the other input terminal (+) is applied to the one input terminal (?) of the operational amplifier 95 through a condenser 94 till a prescribed time elapses from the start of a charging operation to generate a charging start signal from the output terminal of the operational amplifier 95 and electrically conduct the switch unit 4.

Abstract: An electric driving machine has a motor for rotating a flywheel, power transmission for converting rotational drive force of the flywheel into rectilinear drive force and transmitting the rectilinear drive force to an actuator which fires a fastener, and engagement/disengagement arrangement which transmits the rotational drive force of the flywheel to a driver blade of interrupts transmission of the rotational drive force. The electric driving machine is provided with a second switching element connected in series with the engagement/disengagement arrangement and a third switching element connected in shunt with the engagement/disengagement arrangement. When a push lever switch is in an OFF position where driving of a fastener is not ready, the third switching element is held in an ON state.

Abstract: In a centrifugal chamber 9, an elastic rotation shaft 30 and a high-rigidity rotation shaft 34 extend coaxially. When a rotor selected from an angle rotor 17 and a swing rotor 36 which have different sizes and shapes is set in the centrifugal chamber 9, an optimal shaft is connected automatically to the selected rotor. The angle rotor 17 having a low tendency toward mass eccentricity is supported and rotated by the elastic rotation shaft 30 for high-speed rotation. The swing rotor 34 having a high tendency toward mass eccentricity is supported by the high-rigidity shaft 34 for low-speed rotation. Rotation torque is transmitted to the swing rotor 34 from the elastic rotation shaft.

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 centrifugal separator includes an input section for allowing a user to enter operating conditions of a centrifugal separation of a sample accommodated in a rotor driven by a motor. A memory of the centrifugal separator stores a user ID code and a corresponding user name which are registered in advance by the user. Operation of the centrifugal separator is allowed when a user ID code entered through the input section agrees with the registered user ID code.

Abstract: A tool bit holding device for use in percussion apparatuses such as electrically operated hammers is provided. The device includes a tool bit carrier, a front hand-operated grip, and a rear hand-operated grip. The front hand-operated grip is supported by the tool bit carrier so as to be movable in a lengthwise direction and a circumferential direction of the tool bit carrier. The rear hand-operated grip is installed rotatably on a hollow cylinder connected to a casing of the hammer. The removable of a tool bit from the tool bit carrier is accomplished by moving the front grip in the lengthwise direction and then turning it in the circumferential direction to release engagement between the tool bit and the tool bit carrier. The angular orientation of the tool bit carrier relative to the casing of the hammer is accomplished by turning the rear grip relative to the tool bit carrier to shift a angular relation between the tool bit carrier and the casing of the hammer.

Abstract: A percussion tool comprises a cylinder 3 communicated to a pressure accumulating chamber 16 storing pressurized air therein, and a piston 4 slidable in the cylinder 3 when pressurized air is introduced into the cylinder 3 from the pressure accumulating chamber 16 and pressure of the introduced air is applied on the piston 4. A circular groove 6 is recessed on a peripheral surface of the piston 4, the peripheral surface adjacently facing to an inside wall of the cylinder 3. A piston ring 10 is accommodated in the circular groove 6, so as to provide a hermetical sealing between the piston 4 and the cylinder 3. And, a ring bumper 11 made of resilient member is provided in the circular groove 6 adjacent to the piston ring 10 in a sliding direction of the piston 4.