The invention relates to a tool device (10), comprising a shaft (2) and a braking device (12) with at least one brake body (3), in particular in the form of a brake disc, and a brake section (14), wherein the tool device (10) is adapted to, in the course of a braking operation, put the braking device (12) from a release state via a feed state into a braking state, provide, in the release state, a rotationally fixed coupling between the at least one brake body (3) and the shaft (2), so that the at least one brake body (3) rotates with the shaft (2) in the release state, provide, in the feed state, a relative rotational movement between the at least one brake body (3) and the shaft (2) and convert the relative rotational movement into an axial movement (31) of the at least one brake body (3) towards the brake section (14), and exert, in the braking state, a braking force on the shaft (2) by a contact of the at least one brake body (3) with the brake section (14), so that the shaft (2) is braked.

The invention relates to a tool device (10), comprising a shaft (2) and a braking device (12) with at least one brake body (3), in particular in the form of a brake disc, and a brake section (14), wherein the tool device (10) is adapted to, in the course of a braking operation, put the braking device (12) from a release state via a feed state into a braking state, provide, in the release state, a rotationally fixed coupling between the at least one brake body (3) and the shaft (2), so that the at least one brake body (3) rotates with the shaft (2) in the release state, provide, in the feed state, a relative rotational movement between the at least one brake body (3) and the shaft (2) and convert the relative rotational movement into an axial movement (31) of the at least one brake body (3) towards the brake section (14), and exert, in the braking state, a braking force on the shaft (2) by a contact of the at least one brake body (3) with the brake section (14), so that the shaft (2) is braked.

A power tool includes a motor including a rotation shaft; an output shaft to which a cutting blade is attachable; a belt for transmitting a rotational force of the rotation shaft to the output shaft; an intermediate shaft positioned between the rotation shaft and the output shaft on a transmission path of the rotational force; a plurality of pulleys including a first pulley provided on the rotation shaft and rotatable integrally with the rotation shaft and a second pulley through which the intermediate shaft is inserted and having a diameter greater than that of the first pulley, the first pulley and the second pulley supporting the belt and being rotatable in accordance with rotation of the rotation shaft; and a transmission restricting part provided on a transmission path for transmitting rotation of the second pulley to the cutting blade and configured to interrupt or limit transmission of a rotational force.

A power tool includes a motor including a rotation shaft; an output shaft to which a cutting blade is attachable; a belt for transmitting a rotational force of the rotation shaft to the output shaft; an intermediate shaft positioned between the rotation shaft and the output shaft on a transmission path of the rotational force; a plurality of pulleys including a first pulley provided on the rotation shaft and rotatable integrally with the rotation shaft and a second pulley through which the intermediate shaft is inserted and having a diameter greater than that of the first pulley, the first pulley and the second pulley supporting the belt and being rotatable in accordance with rotation of the rotation shaft; and a transmission restricting part provided on a transmission path for transmitting rotation of the second pulley to the cutting blade and configured to interrupt or limit transmission of a rotational force.

An electric work machine (1) includes a motor (1), a manipulatable part (9), a control part (20) configured to perform a first braking control and a second braking control that differ from each other, and a kickback-detection part (20, S30) that detects whether kickback has occurred. The control part energizes the motor in response to detection of user-manipulation of the manipulatable part. In response to detection of kickback, the control part performs the first braking control and thereby causes the motor to generate a first braking force. In response to detection of a state change of the manipulatable part to an unmanipulated or OFF state, the control part performs the second braking control and thereby causes the motor to generate a second braking force, which is weaker than the first braking force.

An electric work machine (1) includes a motor (1), a manipulatable part (9), a control part (20) configured to perform a first braking control and a second braking control that differ from each other, and a kickback-detection part (20, S30) that detects whether kickback has occurred. The control part energizes the motor in response to detection of user-manipulation of the manipulatable part. In response to detection of kickback, the control part performs the first braking control and thereby causes the motor to generate a first braking force. In response to detection of a state change of the manipulatable part to an unmanipulated or OFF state, the control part performs the second braking control and thereby causes the motor to generate a second braking force, which is weaker than the first braking force.

The invention relates to a tool apparatus (10) with a drivable tool (1), comprising a shaft (2) which is coupled to the tool (1), further comprising one or plural braking bodies (3) which in particular are arranged distributed around the shaft (2) in the circumferential direction, wherein the tool apparatus (10) is adapted to bring the one or plural braking bodies (3) from a release state into a braking state in the course of a braking procedure, wherein in the braking state the one or the plural braking bodies (3) are in contact with the shaft and thereby exert a braking force upon the shaft (2), so that the shaft (2) and thereby also the tool (1) are braked and wherein in the release state the one or the plural braking bodies (3) are not in contact with the shaft (2).

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 safety braking device for a machine tool for braking a processing tool driven by means of an electric motor via an output unit, more particularly an output shaft, includes at least one braking device which is provided to halt rotation of the output unit in a braking process. The braking device has at least a first braking stage and a second braking stage. The disclosure further relates to a machine tool having the safety braking device and to a method for operating a safety braking device.