Abstract: A controller 50 that controls a power tool such as, for example, a portable circular saw includes a controller case 70 that houses an electric circuit board 60. Electric elements 61, 62 that generate heat and/or are to be cooled on the electric circuit board 60 contact a thick wall portion 73b of the controller case 70, resulting in heat dissipation resulting in effective cooling of the controller 50.

Abstract: An electric power tool from starting unintentionally by the user, stopping a locked-on state in an unintentional situation by the user, as well as enhances the theft suppressing effect of the electric power tool. The present invention relates to a starting system including an electric power tool and a glove as a wearable device a user puts on. Only when a use permission signal is received from the glove the user puts on, the operational state of the electric power tool changes to a start standby state whereby electrical functions of the tool can then be utilized, and only in the start standby state, the electric power tool is configured to start by an on-operation thereof.

Abstract: In an electric power tool 1 including a motor 20, a cooling fan 24 for cooling the motor 20, a plurality of intake ports 11a through which outside air is introduced by use of said cooling fan 24, and a heating element 50 That generates heat, a heat sink 40 is disposed between the motor 20 and the intake port 11a. The heating element 50 is connected to the heat sink 40 through a heat pipe 30.

Abstract: A separation lock member is provided in a main body cover. When a fixing cover is rotated with respect to the main body cover at a predetermined opening/closing angle (opening angle ?1) and then an unlock operation of the separation lock member is performed, a rotation support shaft can be separated from a support groove 23a, such that the main body cover can be separated from the fixing cover.

Abstract: A compression spring is retained in a spring retaining portion provided in a fixing cover. By a pressing portion formed in a main body cover, the compression spring can be pressed to generate a biasing force in an opening direction of the main body cover. The compression spring is retained in the spring retaining portion. Accordingly, the fixing cover and main body cover can be easily assembled.

Abstract: A separation lock member is provided in a main body cover. When a fixing cover is rotated with respect to the main body cover at a predetermined opening/closing angle (opening angle ?1) and then an unlock operation of the separation lock member is performed, a rotation support shaft can be separated from a support groove 23a, such that the main body cover can be separated from the fixing cover.

Abstract: A compression spring is retained in a spring retaining portion provided in a fixing cover. By a pressing portion formed in a main body cover, the compression spring can be pressed to generate a biasing force in an opening direction of the main body cover. The compression spring is retained in the spring retaining portion. Accordingly, the fixing cover and main body cover can be easily assembled.

Abstract: A dust collection cover may be made from resin for achieving a reduction in its typical weight. In such a configuration, a disk-shaped grinding stone for grinding a steel material is preferably not attachable due to interference of an attachment-restricting portion. It is preferred that only a cup-shaped diamond wheel for work that generally does not produce heated iron powder or the like is attachable.

Abstract: In a grinder, a motor is accommodated in a housing so that an output shaft faces forward, a paddle switch that turns on and off a drive switch of the motor is supported by the housing so that the paddle switch can be operated to move in a direction perpendicular to the output shaft of the motor, and a brake device that brakes rotation of the output shaft is provided on a front side of the motor in the housing. The grinder includes a cooperative mechanism that releases the brake device in response to a pushing operation of pushing the paddle switch toward the housing to turn on the drive switch.

Abstract: In an electric disc grinder, there is provided, between a driven gear and a spindle in a torque transmission system, a C-shaped spring member capable of elastic deformation in a diameter enlarging direction. With respect to the rotating direction, the spring member is engaged with a driving protrusion of the driven gear and a driven protrusion of a joint sleeve of the spindle; when transmitting the rotation of the driven gear to the spindle, the spring member undergoes elastic deformation in the diameter enlarging direction depending on the driven side load, thereby mitigating the starting shock. An abutment surface of the driven protrusion is formed as an inclined surface causing an end portion of the spring member contacting with the abutment surface to slide radially outwards. As a result, the spring member can easily undergo elastic deformation in the diameter enlarging direction.

Abstract: A rotary tool includes a drive device, a driven member configured to be rotatably driven by the drive device, a spindle rotatably supported within a housing, an impact attenuation mechanism disposed between the driven member and the spindle and transmitting rotation of the driven member to the spindle while an impact applied to the driven member being attenuated, and a driven member support bearing rotatably supporting the driven member, so that the driven member can rotate relative to the spindle.

Abstract: An electric tool may include an electric motor, a spindle to which a working tool may be attached, and a torque transmission path provided between the electric motor and the spindle and including a first rotary member and a second rotary member. A torque transmission device may be provided between the first rotary member and the second rotary member and may include a plurality of resiliently deformable torque transmission members.

Abstract: An electric tool includes a housing accommodating a motor, and a break device and an operational member to turn on and turn off a drive switch of the motor. The brake device includes a brake plate fixed to an output shaft of the motor, a brake member is capable of moving toward and away from the brake plate during rotation, and an urging unit urging the brake member toward an abutment position where the brake member abuts on the brake plate. The operational member is provided with a press member that comes into abutment on the brake member through an operation of turning on the drive switch of the motor and rotates the brake member in such a rotational direction as to move away from the brake plate against the urging of the urging unit.

Abstract: An output shaft of a motor is divided into a front shaft (first or second front shaft) and a rear shaft. The first front shaft is to be rotatably supported by a first shaft support plate connected directly to a motor housing. The second front shaft is to be rotatably supported by a second shaft support plate connected to the motor housing with a spacer provided between the second shaft support plate and the motor housing. A braking mechanism including a flange plate, a braking member and a biasing member is mounted to the second shaft support plate and the second front shaft. The first front shaft is used with the first shaft support plate to realize a power tool without the braking mechanism. The second front shaft is used with the second shaft support plate and the spacer to realize a power tool without the braking mechanism.

Abstract: An electric tool may include an electric motor, a spindle to which a working tool may be attached, and a torque transmission path provided between the electric motor and the spindle and including a first rotary member and a second rotary member. A torque transmission device may be provided between the first rotary member and the second rotary member and may include a plurality of resiliently deformable torque transmission members.

Abstract: A grinder can include a stopper projection provided to a grinding stone cover and position a stopper abutting portion on a side of a gear housing in order to restrict a position adjustable range through abutment of the stopper projection to the stopper abutting portion in a position where the grinding stone cover has rotated in a rotational direction of the grinding stone by a set angle.

Abstract: In a grinder, a motor is accommodated in a housing so that an output shaft faces forward, a paddle switch that turns on and off a drive switch of the motor is supported by the housing so that the paddle switch can be operated to move in a direction perpendicular to the output shaft of the motor, and a brake device that brakes rotation of the output shaft is provided on a front side of the motor in the housing. The grinder includes a cooperative mechanism that releases the brake device in response to a pushing operation of pushing the paddle switch toward the housing to turn on the drive switch.

Abstract: A grinder includes a lock mechanism, attached to a bearing box, that inhibits detachment/rotation of a cylindrical portion of a wheel cover. The lock mechanism includes a ring-shaped lock member, with a larger diameter than the cylindrical portion, that surrounds the bearing box and has a front side inner edge protruding engagement hook. The lock member can slide between a front-side lock released position at which the engagement hook is separated from the bearing box to the front side and the cylindrical portion can be attached/detached to/from the bearing box, and a rear-side locked position at which the engagement hook passes through the cylindrical portion that surrounds the bearing box and engages with a bearing box outer periphery such that a front portion is contained within a gear housing in a plan view. The lock mechanism also includes a torsion spring that urges the lock member to the locked position.

Abstract: In a grinder, a spindle protruding from a main body including a brake device is provided with an inner member. The inner member contacts a pressing portion provided integrally with the spindle and is pressed toward a tip end of the spindle when the spindle is braked by the brake device. A nut member can be screwed on the tip end of the spindle so that a disc-like tool though which the spindle extends perpendicularly can be held between the inner member and the nut member. The inner member comprises a locking member that contacts the pressing portion and is pressed toward the disc-like tool when the brake device is operated, and an inner flange which is detachably attached to the locking member so as to be rotatable together with the locking member.

Abstract: A dust collection cover may be made from resin for achieving a reduction in its typical weight. In such a configuration, a disk-shaped grinding stone for grinding a steel material is preferably not attachable due to interference of an attachment-restricting portion. It is preferred that only a cup-shaped diamond wheel for work that generally does not produce heated iron powder or the like is attachable.