Abstract: Handheld power tools with kickback detection and methods of detecting a kickback condition of a handheld power tool are disclosed herein. The methods move an implement of the handheld power tool within an implement motion plane and detect motion of the handheld power tool. The methods also include determining that the kickback condition exists based, at least in part, on the motion of the handheld power tool. In some embodiments, the handheld power tool is a circular saw that includes a user-actuated assembly. The user-actuated assembly includes a motion sensor, a controller, and a motor. The circular saw also includes a workpiece support and a pivot. The motion sensor is configured to detect acceleration along an acceleration detection axis that extends a threshold pivot axis-acceleration axis distance of at most 4 cm from a pivot axis of the pivot.

Abstract: Circular saws having a blade that moves relative to a stationary base structure during operative use of the circular saws to cut a workpiece and methods of detecting a kickback condition of such circular saws. The circular saws include a base structure, a user-actuated assembly, an attachment structure, and a controller. The attachment structure is configured to permit constrained relative motion between the base structure and the user-actuated assembly in a motion direction and during operative use of the circular saw to cut the workpiece. A motion sensor is configured to generate a motion signal indicative of motion of the user-actuated assembly along the motion direction. The controller is programmed to initiate a kickback response of the circular saw responsive to the motion signal being indicative of a kickback condition of the circular saw.

Abstract: Circular saws having a blade that moves relative to a stationary base structure during operative use of the circular saws to cut a workpiece and methods of detecting a kickback condition of such circular saws. The circular saws include a base structure, a user-actuated assembly, an attachment structure, and a controller. The attachment structure is configured to permit constrained relative motion between the base structure and the user-actuated assembly in a motion direction and during operative use of the circular saw to cut the workpiece. A motion sensor is configured to generate a motion signal indicative of motion of the user-actuated assembly along the motion direction. The controller is programmed to initiate a kickback response of the circular saw responsive to the motion signal being indicative of a kickback condition of the circular saw.

Abstract: Handheld power tools with kickback detection and methods of detecting a kickback condition of a handheld power tool are disclosed herein. The methods include moving an implement of the handheld power tool within an implement motion plane and in detecting motion of the handheld power tool. The methods also include determining that the kickback condition exists based, at least in part, on the motion of the handheld power tool. In some embodiments, the handheld power tool is a circular saw that includes a user-actuated assembly. The user-actuated assembly includes a motion sensor, a controller, and a motor. The circular saw also includes a workpiece support and a pivot. The motion sensor is configured to detect acceleration along an acceleration detection axis that extends a threshold pivot axis-acceleration axis distance of at most 4 cm from a pivot axis of the pivot.

Abstract: Power tools and methods of operating power tools are disclosed herein. The power tools include a motor including a motor shaft configured to rotate about a shaft rotational axis. The power tools also include a sensor assembly configured to generate a differential voltage signal that is indicative of a distance between an individual and a cutting tool being less than a threshold distance. The sensor assembly also is configured to produce a sensor assembly output that is based upon the differential voltage signal. The power tools further include an analysis circuit configured to receive the sensor assembly output and to generate a trigger signal responsive to the sensor assembly output being outside a nominal sensor assembly output range. The power tools also include a mechanical reaction mechanism configured to insulate the individual from the cutting tool responsive to receipt of the trigger signal.