Apparatus and method for detecting dangerous conditions in power equipment
First Claim
1. A method of detecting a dangerous condition between a person and a woodworking machine, where the woodworking machine includes a cutting tool electrically coupled to an arbor, and where the cutting tool and arbor are electrically isolated, the method comprising:
- imparting an electrical signal to the cutting tool through a capacitive coupling that includes two spaced-apart conductors, where at least a portion of the surface of the arbor is one of the conductors; and
monitoring the electrical signal for changes indicative of the dangerous condition.
2 Assignments
0 Petitions
Accused Products
Abstract
Woodworking machines are disclosed having electrically conductive cutting tools adapted to cut workpieces. The machines include a contact detection system capacitively coupled to the cutting tool, and adapted to detect contact between a person and the cutting tool. The machines also include a reaction system configured to cause one or more predetermined actions to take place upon detection of contact between a person and the cutting tool by the contact detection system.
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Citations
25 Claims
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1. A method of detecting a dangerous condition between a person and a woodworking machine, where the woodworking machine includes a cutting tool electrically coupled to an arbor, and where the cutting tool and arbor are electrically isolated, the method comprising:
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imparting an electrical signal to the cutting tool through a capacitive coupling that includes two spaced-apart conductors, where at least a portion of the surface of the arbor is one of the conductors; and
monitoring the electrical signal for changes indicative of the dangerous condition. - View Dependent Claims (2, 3, 4, 5)
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6. A woodworking machine comprising:
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a motor;
an electrically isolated arbor configured to be driven by the motor;
a cutting tool coupled to the arbor;
an excitation system adapted to generate an electrical signal;
a capacitive coupling adapted to capacitively couple the excitation system to the arbor to transfer at least a portion of the electrical signal to the cutting tool, where the capacitive coupling includes a conductive plate substantially encircling the arbor; and
an insulator substantially encircling the conductive plate. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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15. A band saw comprising:
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a motor;
at least two spaced-apart wheels, where at least one wheel is driven by the motor;
a band blade extending around the wheels, where the band blade is electrically isolated;
signal generation circuitry adapted to generate an electrical signal;
a capacitive coupling adapted to capacitively couple the signal generation circuitry to the band blade to transfer at least a portion of the electrical signal to the band blade; and
detection circuitry configured to monitor the electrical signal on the band blade for changes indicative of a dangerous condition between a person and the band blade and to trigger some action to mitigate the dangerous condition when the changes indicative of the dangerous condition are detected. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A woodworking machine comprising:
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a motor;
a cutting tool driven by the motor, where the cutting tool is electrically isolated;
an excitation system adapted to generate an electrical signal;
a capacitive coupling adapted to capacitively couple the excitation system to the cutting tool to transfer at least a portion of the electrical signal to the cutting tool, where the capacitive coupling includes a conductive plate adjacent the cutting tool; and
an insulating spacer intermediate the cutting tool and conductive plate. - View Dependent Claims (22, 23)
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24. A woodworking machine comprising:
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a motor;
a cutting tool driven by the motor, where the cutting tool is electrically isolated;
an excitation system adapted to generate an electrical signal;
means for capacitively-coupling the excitation system to the cutting tool to transfer at least a portion of the electrical signal to the cutting tool; and
means for positioning the capacitive coupling means in an operable configuration in the woodworking machine. - View Dependent Claims (25)
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Specification