Patent ID: 6957601

Claim:
An up-cut chop saw, comprising: a frame; a work surface supported by the frame and adapted to support a workpiece; a rotatable blade configured to cut a workpiece on the work surface by moving from below the work surface to a position where at least part of the blade is above the work surface, where the blade is electrically isolated so that it may carry an electric signal; at least one brace member coupled to move upward with the blade, at least one motor configured to drive the blade; at least one actuating mechanism operable to move the blade upward to a position where at least part of the blade is above the work surface; a detection system adapted to impart an electric signal to the blade and to monitor the signal for a predetermined change indicative of contact between a person and the blade; and a reaction system configured to retract the blade from a position where at least part of the blade is above the work surface to a position where the blade is completely below the work surface upon detection by the detection system of the predetermined change indicative of contact between a person and the blade; where the actuating mechanism is further operable to lower the blade below the work surface after the blade has been moved to a position where at least part of the blade is above the work surface; where the reaction system is configured to operate the actuating mechanism to lower the blade upon detection by the detection system of the predetermined change indicative of contact between a person and the blade; and where the reaction system includes a brake mechanism configured to engage the brace member and stop the upward motion of the blade upon detection by the detection system of the predetermined change indicative of contact between a person and the blade.