Object proximity detection in a saw
First Claim
1. A table saw comprising:
- an implement extending through an opening in a throat plate;
a motor operatively connected to the implement;
a capacitive sensor positioned in the throat plate, the capacitive sensor comprising a plurality of capacitive sensing elements arranged in a predetermined two-dimensional arrangement on a surface of the capacitive sensor, the capacitive sensor being configured to generate a plurality of capacitance signals using the plurality of capacitive sensing elements during operation of the motor; and
a controller including a digital logic device operatively connected to the motor and the capacitive sensor, the controller being configured to;
operate the motor to move the implement;
identify an object in proximity to the capacitive sensor in response to a change in a level of capacitance in a plurality of capacitive signals generated by the plurality of capacitive sensing elements;
identify that the object corresponds to a body part of an operator in response to the change in the plurality of capacitance signals indicating a capacitance level that exceeds a predetermined threshold;
identify a location and a path of movement for the body part of the operator over the capacitive sensor based on the plurality of capacitance signals from the plurality of capacitive sensing elements in the capacitive sensor;
deactivate the motor in response to a trajectory of the path of movement of the body part intersecting the implement prior to contact between the body part of the operator and the implement while the location of the body part is outside of a predetermined distance of the implement; and
deactivate the motor in response to the location of the body part being within the predetermined distance of the implement.
1 Assignment
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Accused Products
Abstract
A method for detection of proximity between an object and an implement in a table saw includes operating a motor in the table saw to move the implement, generating, with a capacitive sensor formed in a throat plate around the implement in the table saw, a capacitance signal during operation of the motor, identifying, with a controller operatively connected to the capacitive sensor, an object in proximity to the capacitive sensor in response to a change in a level of capacitance in the capacitance signal, and deactivating, with the controller, the motor in the table saw in response to the change in the capacitance signal indicating a capacitance level that exceeds a predetermined threshold corresponding to a body part of an operator.
81 Citations
5 Claims
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1. A table saw comprising:
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an implement extending through an opening in a throat plate; a motor operatively connected to the implement; a capacitive sensor positioned in the throat plate, the capacitive sensor comprising a plurality of capacitive sensing elements arranged in a predetermined two-dimensional arrangement on a surface of the capacitive sensor, the capacitive sensor being configured to generate a plurality of capacitance signals using the plurality of capacitive sensing elements during operation of the motor; and a controller including a digital logic device operatively connected to the motor and the capacitive sensor, the controller being configured to; operate the motor to move the implement; identify an object in proximity to the capacitive sensor in response to a change in a level of capacitance in a plurality of capacitive signals generated by the plurality of capacitive sensing elements; identify that the object corresponds to a body part of an operator in response to the change in the plurality of capacitance signals indicating a capacitance level that exceeds a predetermined threshold; identify a location and a path of movement for the body part of the operator over the capacitive sensor based on the plurality of capacitance signals from the plurality of capacitive sensing elements in the capacitive sensor; deactivate the motor in response to a trajectory of the path of movement of the body part intersecting the implement prior to contact between the body part of the operator and the implement while the location of the body part is outside of a predetermined distance of the implement; and deactivate the motor in response to the location of the body part being within the predetermined distance of the implement. - View Dependent Claims (2, 3, 4, 5)
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Specification