A handheld work apparatus has a drive motor which drives a work tool rotationally via a belt drive. The belt drive has a first, driving pulley and a second, driven pulley. The second pulley is connected fixedly to the work tool so as to rotate therewith. The rotational speed of the second pulley is lower during operation than that of the first pulley. A brake unit acts on the belt drive. A first drive belt of a first stage and a second drive belt of a second stage act between the pulleys to transfer the drive torque. The belts each bring about a rotational speed reduction. The belt drive includes a redirection roll which bears against the belt, via which the highest drive torque is transmitted during operation. As a result, a braking operation of the work tool is enabled independently of the rotational speed of the tool.

A handheld work apparatus has a drive motor which drives a work tool rotationally via a belt drive. The belt drive has a first, driving pulley and a second, driven pulley. The second pulley is connected fixedly to the work tool so as to rotate therewith. The rotational speed of the second pulley is lower during operation than that of the first pulley. A brake unit acts on the belt drive. A first drive belt of a first stage and a second drive belt of a second stage act between the pulleys to transfer the drive torque. The belts each bring about a rotational speed reduction. The belt drive includes a redirection roll which bears against the belt, via which the highest drive torque is transmitted during operation. As a result, a braking operation of the work tool is enabled independently of the rotational speed of the tool.

A safety system for a power tool having a motor and a cutting tool driven by the motor includes a control device configured to detect a direct contact of a conductive material with the cutting tool, the direct contact of the conductive material with the cutting tool defining a contact event, and a braking device movable between a retracted position and an engaged position. The control device is configured to interrupt electrical power to the motor and control the braking device to the engaged position when the contact event is detected.

Various safety systems for power tools, and in particular table saws include detection systems for detecting a dangerous condition relative to a blade of the power tool, reaction systems for taking mitigation action in response to detection of a dangerous condition. The safety system may detect, prevent, and/or mitigate a dangerous condition associated with the power tool.

Various safety systems for power tools, and in particular table saws include detection systems for detecting a dangerous condition relative to a blade of the power tool, reaction systems for taking mitigation action in response to detection of a dangerous condition. The safety system may detect, prevent, and/or mitigate a dangerous condition associated with the power tool.

A handheld work apparatus has a drive motor which drives a work tool in rotation via a belt drive. The belt drive has at least one first, driving pulley and at least one second, driven pulley. Between the first pulley and the second pulley there acts at least one drive belt for transmitting the drive torque. A second pulley is connected to the tool for conjoint rotation. The rotational speed of the second pulley is less than the rotational speed of the first pulley during operation. The work apparatus has a brake unit which acts on the first pulley. The belt drive includes at least one redirection roll. During braking, at least one redirection roll bears on the tight side of each drive belt which acts between the first pulley and the second pulley. This allows a simple structure and safe braking of the work tool.

A handheld work apparatus has a drive motor which drives a work tool in rotation via a belt drive. The belt drive has at least one first, driving pulley and at least one second, driven pulley. Between the first pulley and the second pulley there acts at least one drive belt for transmitting the drive torque. A second pulley is connected to the tool for conjoint rotation. The rotational speed of the second pulley is less than the rotational speed of the first pulley during operation. The work apparatus has a brake unit which acts on the first pulley. The belt drive includes at least one redirection roll. During braking, at least one redirection roll bears on the tight side of each drive belt which acts between the first pulley and the second pulley. This allows a simple structure and safe braking of the work tool.

Machine vision apparatus tracks a distinctive object in relation to a hazardous location on a work surface of a modified band saw in two, three, or four (3-D+T) dimensions, and calculates whether to send an immediate shut-down signal to the band saw. Cameras and an image processor are mounted on the band saw. The signal causes an integrated blade-arresting or stopping mechanism to immediately shift the idler wheel, removing blade tension and disconnecting the blade which is then braked to a complete, safe stop before an approaching blue-gloved hand can touch the blade.

Machine vision apparatus tracks a distinctive object in relation to a hazardous location on a work surface of a modified band saw in two, three, or four (3-D+T) dimensions, and calculates whether to send an immediate shut-down signal to the band saw. Cameras and an image processor are mounted on the band saw. The signal causes an integrated blade-arresting or stopping mechanism to immediately shift the idler wheel, removing blade tension and disconnecting the blade which is then braked to a complete, safe stop before an approaching blue-gloved hand can touch the blade.

A safety system is provided for a power tool having a motor-driven cutting blade, a safety mechanism operable by a controller to stop and/or move the cutting blade and a blade guard. The safety system includes an electrically active surface provided on the blade guard that is configured to change an electrical characteristic in response to contact between the body of an operator and the active surface. An active surface controller is operable to provide electrical power to the electrically active surface, to generate a signal in response to the change in the electrical characteristic, the signal indicative of an unsafe condition, and to transmit the signal to the controller for the safety mechanism.