Safety systems for power equipment
First Claim
Patent Images
1. A machine comprising:
- an operative structure adapted to perform a task, where the operative structure includes a circular blade having a perimeter and teeth disposed about the perimeter, where the blade is adapted to spin, and where the blade when spinning cuts an object that moves into contact with the teeth;
an electronic detection circuit including an electrical connection to the blade, where the electronic detection circuit is configured to detect when a person is in contact with the teeth when the blade is spinning; and
an electrically triggerable actuator supported by the operative structure and electrically connected to the electronic detection circuit, where the actuator generates a force that causes the blade to stop cutting the person within 10 milliseconds after being triggered if the person moves into contact with the teeth at a rate of one foot per second or less.
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Accused Products
Abstract
Machines with safety systems are disclosed. The machine may take the form of woodworking machines including table saws, band saws, miter saws, hand-held circular saws, pneumatic chop saws, radial-arm saws, jointers, planars, routers and shapers. The machines may include an operative structure configured to perform a task, where the operative structure includes a cutting tool adapted to move in at least one motion, and a safety system adapted to detect the occurrence of an unsafe condition between a person and the cutting tool and for mitigating the unsafe condition. The safety system may include a detection subsystem and a reaction subsystem.
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Citations
29 Claims
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1. A machine comprising:
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an operative structure adapted to perform a task, where the operative structure includes a circular blade having a perimeter and teeth disposed about the perimeter, where the blade is adapted to spin, and where the blade when spinning cuts an object that moves into contact with the teeth; an electronic detection circuit including an electrical connection to the blade, where the electronic detection circuit is configured to detect when a person is in contact with the teeth when the blade is spinning; and an electrically triggerable actuator supported by the operative structure and electrically connected to the electronic detection circuit, where the actuator generates a force that causes the blade to stop cutting the person within 10 milliseconds after being triggered if the person moves into contact with the teeth at a rate of one foot per second or less. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A machine comprising:
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an operative structure adapted to perform a task, where the operative structure includes a circular blade having a perimeter and teeth disposed about the perimeter, where the blade is adapted to spin; and a safety system adapted to detect the occurrence of contact between a person and the blade when the blade is spinning, where the safety system includes an electronic circuit adapted to detect the contact, and a reaction subsystem electrically connected to the electronic circuit and adapted to mitigate injury from the contact; where the reaction subsystem includes an electrically triggerable actuator supported by the operative structure and connected to the electronic circuit, where the electronic circuit triggers the actuator upon detection of the contact, and where the actuator generates a force that causes the blade to stop cutting the person within 10 milliseconds after being triggered if the person moves into contact with the teeth at a rate of one foot per second or less; and where the reaction subsystem includes a brake mechanism adapted to stop the spinning of the blade within 10 milliseconds after the actuator is triggered. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A machine comprising:
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an operative structure adapted to perform a task, where the operative structure includes a circular blade having a perimeter and teeth disposed about the perimeter, where the blade is adapted to spin, and where the blade when spinning cuts an object that moves into contact with the teeth; a detection circuit to detect when a person is in contact with the teeth when the blade is spinning, where the detection circuit includes an oscillator that generates an oscillating signal, where the detection circuit also includes an electrical connection between the oscillator and the blade, where the oscillating signal is imparted on the blade through the electrical connection, where the detection circuit further includes a controller that detects a change in the oscillating signal on the blade indicative of the person being in contact with the teeth when the blade is spinning, and where the detection circuit generates a detection signal when the controller detects the change in the oscillating signal on the blade; a firing circuit connected to the detection circuit to receive the detection signal, where the firing circuit outputs electric current upon receiving the detection signal; and a reaction system to stop the blade from cutting the person within 10 milliseconds if the person moves into contact with the teeth at a rate of one foot per second, where the 10 milliseconds is measured from the generation of the detection signal, where the reaction system includes an actuator with a spring or an explosive, where the actuator is connected to the firing circuit to receive the electric current output by the firing circuit, where the electric current received by the actuator from the firing circuit heats a component in the actuator to trigger the spring or explosive to generate a force, and where the reaction system further includes at least one of; i. a brake to stop the blade, where the force from the spring or explosive causes the brake to stop the spinning of the blade within 10 milliseconds after the spring or explosive is triggered, and ii. an arbor block supporting the blade, where the force from the spring or explosive causes the arbor block to move and retract the blade at least some amount away from the contact with the person. - View Dependent Claims (25, 26, 27, 28, 29)
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Specification