US Patent 8490527 Power equipment with systems to mitigate or prevent injury

Woodworking machines are disclosed having cutting tools for cutting workpieces. The machines include a detection system adapted to detect one or more dangerous conditions between a person and the cutting tool. The machines also include a mechanism having a moveable component adapted to move upon detection of the dangerous condition by the detection system. Movement of the moveable component contributes to one or more of the following actions to mitigate or prevent injury to the person: deceleration of the cutting tool, retraction of the cutting tool, and placement of a barrier over at least a part of the cutting tool. An actuator is adapted to move the moveable component at a high acceleration when the dangerous condition is detected.