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 blade for cutting workpieces;
a motor configured to drive the blade;
a structure supporting the blade and configured to allow the blade to retract; and
at least one electromagnet to trigger a retraction of the blade, and
a circuit that controls the at least one electromagnet, where the circuit is configured to supply current to the at least one electromagnet in a first direction to create a magnetic field and in a second direction to reverse the magnetic field.
2. The power tool of claim 1 , where the circuit that controls the at least one electromagnet with a microprocessor.
3. A power tool comprising:
a blade for cutting workpieces;
a motor configured to drive the blade;
a structure supporting the blade and configured to allow the blade to retract;
at least one electromagnet to trigger a retraction of the blade; and
a circuit that controls the at least one electromagnet with a microprocessor, where the circuit is configured to supply current to the at least one electromagnet in a first direction to create a magnetic field and in a second direction to help dissipate the magnetic field.
4. The power tool of claim 1 , 2 , or 3 , further comprising a detection system configured to detect a dangerous condition between a person and the cutting tool, and where the at least one electromagnet triggers the retraction of the blade upon detection of the dangerous condition.
5. A power tool comprising:
a blade for cutting workpieces;
a motor configured to drive the blade;
a structure supporting the blade and configured to allow the blade to retract;
at least one electromagnet to control retraction of the blade, and
a circuit that controls the at least one electromagnet, where the circuit is configured to supply current to the at least one electromagnet in a first direction to create a magnetic field and in a second direction opposite the first direction.
6. The power tool of claim 5 , where the circuit controls the at least one electromagnet with a microprocessor.
7. A power tool comprising:
a blade for cutting workpieces;
a motor configured to drive the blade;
a structure supporting the blade and configured to allow the blade to retract;
at least one electromagnet to control retraction of the blade; and
a circuit that manages the at least one electromagnet with a microprocessor, where the circuit is configured to supply current to the at least one electromagnet in a first direction to create a magnetic field and in a second direction to help dissipate the magnetic field.
8. The power tool of claim 5 , 6 , or 7 , further comprising a detection system configured to detect a dangerous condition between a person and the cutting tool, and where the at least one electromagnet causes the blade to retract upon detection of the dangerous condition.