Actuators for power tool safety systems
Fast-acting and low-inertia actuators useable in various applications where a high force must be applied very quickly are disclosed. Power tools with detection systems configured to detect a dangerous condition between a person and a cutting tool are disclosed. In power tools, for example in a woodworking machine, a fast-acting and low-inertial actuator as disclosed herein can be used to retract a blade upon detection of a dangerous condition by a detection system. The actuator includes a charge of pressurized fluid and one or more electromagnets to selectively retain or release the pressurized fluid.
1. A power tool comprising:
a cutting tool for cutting workpieces;
a motor configured to drive the cutting tool;
a detection system configured to detect a dangerous condition between a person and the cutting tool;
a support structure associated with the cutting tool and configured to allow the cutting tool to retract; and
an actuator configured to produce at least 4,000 Newtons of force within 0 to 3 milliseconds after detection of the dangerous condition by the detection system, where the actuator is further configured to be triggered and reset a plurality of times without a user having to replace a part of the power tool.
2. The power tool of claim 1 , where the force produced by the actuator causes the cutting tool to retract and to reach a peak acceleration of at least 20 to 500 Gs during retraction.