A blade attachment-detachment assisting apparatus includes a nut rotating part having an engagement pin that engages with an engagement hole of a nut, a nut grip part that grips an annular groove of the nut, a housing that supports the nut rotating part rotatably by a predetermined angle, and a lock mechanism. The nut rotating part is capable of advancing and retreating, relative to the housing, to a protrusion position and a fixing position at which engagement between the nut grip part and the nut is kept, and is fixed to the housing with the intermediary of a spring. The lock mechanism includes an inside surface by which advancing and retreating of the nut rotating part are restricted through engagement of the nut rotating part with the housing when the housing is rotated in one direction at the fixing position to which the nut rotating part has been pushed.

A tool-holder unit for machining block or slab materials is moveable above a working plane on which the block or slab material is laid. The tool-holder unit includes a spindle with a circular blade and a coupling assembly that couples a second machining tool with the spindle. The tool-unit further includes a tool-holder; a mechanical coupling device configured to rotationally integrate the tool-holder and the spindle; a first axial locking element configured to removably lock the tool-holder on the spindle; a substantially cylindrical shank extending from the tool-holder; a substantially cylindrical housing seat axially positioned in the spindle or a tool-holder coupling element; and a second axial locking element configured to removably lock the tool-holder in the spindle, the axial locking element being configured to removably lock the shank in the respective housing seat.

A tool-holder unit for machining block or slab materials is moveable above a working plane on which the block or slab material is laid. The tool-holder unit includes a spindle with a circular blade and a coupling assembly that couples a second machining tool with the spindle. The tool-unit further includes a tool-holder; a mechanical coupling device configured to rotationally integrate the tool-holder and the spindle; a first axial locking element configured to removably lock the tool-holder on the spindle; a substantially cylindrical shank extending from the tool-holder; a substantially cylindrical housing seat axially positioned in the spindle or a tool-holder coupling element; and a second axial locking element configured to removably lock the tool-holder in the spindle, the axial locking element being configured to removably lock the shank in the respective housing seat.

Twisting of a locking member due to cogging torque is reduced without lowering the locking and unlocking operability for a user. A power tool includes a housing, an electric motor located inside the housing and including a permanent magnet, a shaft rotatable about an axis relative to the housing to transmit power from the electric motor, a locking member movable between a lock position and an unlock position in a nonenergized state of the electric motor and engageable with the shaft at the lock position to lock rotation of the shaft, and an abutting member that applies, to the locking member at the lock position, a force in a direction opposite to an axial torque caused by the permanent magnet and applied to the locking member.

Twisting of a locking member due to cogging torque is reduced without lowering the locking and unlocking operability for a user. A power tool includes a housing, an electric motor located inside the housing and including a permanent magnet, a shaft rotatable about an axis relative to the housing to transmit power from the electric motor, a locking member movable between a lock position and an unlock position in a nonenergized state of the electric motor and engageable with the shaft at the lock position to lock rotation of the shaft, and an abutting member that applies, to the locking member at the lock position, a force in a direction opposite to an axial torque caused by the permanent magnet and applied to the locking member.

A power tool, such as an oscillating multi-tool, is configured to drive a tool accessory in an oscillating manner. The power tool includes a motor, and a spindle supported to be rotatable around a driving axis and configured to pivotally oscillate the tool accessory, which is removably mounted on the spindle, using power generated by the motor. An inner housing of the power tool houses the motor and the spindle, and has at least one airflow inlet and at least one airflow outlet. An outer housing of the power tool houses the inner housing and is elastically connected to the inner housing via at least one elastic member to be movable relative to the inner housing. A partition is disposed between the at least one inlet and the at least one outlet. The partition divides a space defined between the inner and outer housings into first and second airflow spaces.

An electrospindle includes a motor for moving a tool and a motor shaft for transmitting motion from the motor to the tool. The electrospindle has a gripping head of the tool and a coupling of the tool to the motor shaft, and the gripping head includes two flanges, between which a portion of the tool and at least one thrust nut of a first flange can be interposed toward a counterflange, so as to hold the tool in position. The electrospindle further includes an insert coupled by screwing to the free end of the motor shaft, the thrust nut being coupled on an end portion of the insert.

An electrospindle includes a motor for moving a tool and a motor shaft for transmitting motion from the motor to the tool. The electrospindle has a gripping head of the tool and a coupling of the tool to the motor shaft, and the gripping head includes two flanges, between which a portion of the tool and at least one thrust nut of a first flange can be interposed toward a counterflange, so as to hold the tool in position. The electrospindle further includes an insert coupled by screwing to the free end of the motor shaft, the thrust nut being coupled on an end portion of the insert.

A tool-holder unit for machining block or slab materials is moveable above a working plane on which the block or slab material is laid. The tool-holder unit includes a spindle with a circular blade and a coupling assembly that couples a second machining tool with the spindle. The tool-unit further includes a tool-holder; a mechanical coupling device configured to rotationally integrate the tool-holder and the spindle; a first axial locking element configured to removably lock the tool-holder on the spindle; a substantially cylindrical shank extending from the tool-holder; a substantially cylindrical housing seat axially positioned in the spindle or a tool-holder coupling element; and a second axial locking element configured to removably lock the tool-holder in the spindle, the axial locking element being configured to removably lock the shank in the respective housing seat.

A tool-holder unit for machining block or slab materials is moveable above a working plane on which the block or slab material is laid. The tool-holder unit includes a spindle with a circular blade and a coupling assembly that couples a second machining tool with the spindle. The tool-unit further includes a tool-holder; a mechanical coupling device configured to rotationally integrate the tool-holder and the spindle; a first axial locking element configured to removably lock the tool-holder on the spindle; a substantially cylindrical shank extending from the tool-holder; a substantially cylindrical housing seat axially positioned in the spindle or a tool-holder coupling element; and a second axial locking element configured to removably lock the tool-holder in the spindle, the axial locking element being configured to removably lock the shank in the respective housing seat.