A power tool and methods are provided for detecting objects (e.g., flesh or other materials) in the operating path of a power tool's output component (e.g., saw blade or drill bit). An object detection sensor in the power tool generates an output signal indicative of a type of material detected in the operating path of the power tool. A power tool controller receives the object detection sensor output and determines when a material in the operating path of the power tool changes. The controller changes operation of a motor of the power tool (e.g., increasing or decreasing speed or stopping the motor) in response to the detected material change. The object detection sensor may include, for example, an RF sensor, a capacitive sensor, a camera, a conductivity probe, or an ultrasound probe.

A power tool includes a moving implement, implement arrest mechanism, light emitters, photodetector, and controller. The controller activates a first emitter to direct light with a wavelength between 800 nm and 1100 nm on an object and identifies a first reflectance level of the object from a reflectance signal from the photodetector. The controller activates a second emitter to direct light with a wavelength between 1350 nm and 1800 nm on the object and identifies a second reflectance level of the object from the photodetector. The controller activates the implement arrest mechanism to prevent contact between the object and the moving implement if a ratio corresponding to the first identified reflectance level and the second identified reflectance level exceeds a predetermined threshold.

Optical imaging apparatus and a machine vision camera system for an alarm protecting a person's hands when working at a motorized cutting or abrading machine, uses trains of sets of mirrors to define four spaced-apart viewpoints and transfer non-overlapping scenes on to an image sensor of a single camera. An optical axis from each viewpoint allows a cuboidal protected volume to be created. The cuboid may have vertical sides. Recognizable objects inside that volume cause the machine to stop, while objects near but outside the volume cause the apparatus to raise an alarm.

The present disclosure provides a system and method for automatically stopping powered machinery, which employs a number of vision sensors. In one embodiment, the system includes vision sensors arranged such that they image different zones defined relative to the cutting tool. The images captured by the vision sensors are processed by the system in real time. If the user's body (e.g., hands) is deemed to be in an unsafe area relative to the cutting tool, the system is configured to automatically stop the cutting tool.

An output member is configured to transfer rotation and torque from a motor of a power tool to a working element of the power tool. The working element is configured to contact a workpiece. The output member includes a hub, an outer shell, and an isolator. The hub is configured to be driven rotationally about an axis of rotation by the motor of the power tool. The outer shell is configured to be coupled to the working element of the power tool. The isolator is interposed between the hub and the outer shell and is configured to electrically isolate the hub from the outer shell.

A working machine may include: a working unit; a prime mover configured to drive the working unit; an image capture unit configured to capture image data of an area near the working unit; and a control unit. The working machine may be configured to operate in a normal mode in which the working machine operates normally and in a safe mode in which the working machine operates more safely than in the normal mode, and the control unit may be configured to operate the working machine in the safe mode when the control unit determines that an object is approaching the working unit based on a number of pixels of which hue when the pixels are represented in an HSV format is within a predetermined range among pixels included in the image data captured by the image capture unit.

A method for detection of false positive condition that an object is in contact with an implement in a power tool includes sampling an electrical signal received from the implement, identifying in-phase and a quadrature components of the sampled electrical signal, identifying a magnitude of each of the samples with reference to the in-phase component and the quadrature component for the samples, detecting an object approaching the implement with reference to the plurality of samples, identifying a signal-to-noise ratio for the samples, and identifying a false positive condition for the detected object with reference to the identified signal-to-noise ratio for the identified samples.

A power tool and methods are provided for detecting objects (e.g., flesh or other materials) in the operating path of a power tool's output component (e.g., saw blade or drill bit). An object detection sensor in the power tool generates an output signal indicative of a type of material detected in the operating path of the power tool. A power tool controller receives the object detection sensor output and determines when a material in the operating path of the power tool changes. The controller changes operation of a motor of the power tool (e.g., increasing or decreasing speed or stopping the motor) in response to the detected material change. The object detection sensor may include, for example, an RF sensor, a capacitive sensor, a camera, a conductivity probe, or an ultrasound probe.

A safety system for a power miter saw comprises a support member, at least one multidirectional manipulator including a workpiece holder member moveably mounted to the support member for securing a workpiece in place, and a control box. The workpiece holder member includes a presence indicator operatively connected to the control box and configured to detect the physical presence of a saw operator's hand on the at least one multidirectional manipulator when the saw operator's hand engages the presence indicator. The control box is operatively connectable to a trigger switch of the power miter saw so that an electric motor of the power miter saw is activated only when both the presence indicator of the safety system and the trigger switch of the power miter saw are engaged by both hands of an operator of the power miter saw.

A power tool and methods are provided for detecting objects (e.g., flesh or other materials) in the operating path of a power tool's output component (e.g., saw blade or drill bit). An object detection sensor in the power tool generates an output signal indicative of a type of material detected in the operating path of the power tool. A power tool controller receives the object detection sensor output and determines when a material in the operating path of the power tool changes. The controller changes operation of a motor of the power tool (e.g., increasing or decreasing speed or stopping the motor) in response to the detected material change. The object detection sensor may include, for example, an RF sensor, a capacitive sensor, a camera, a conductivity probe, or an ultrasound probe.