Power tool having object detection
AssigneeMilwaukee Electric Tool Corporation
InventorMatthew J. Mergener
Life of this patent
Estimating the term…
Abstract
A power tool and methods are provided for detecting objects (e.g., flesh or other materials) in the operating path of a power tool's output component (e.g., saw blade or drill bit). An object detection sensor in the power tool generates an output signal indicative of a type of material detected in the operating path of the power tool. A power tool controller receives the object detection sensor output and determines when a material in the operating path of the power tool changes. The controller changes operation of a motor of the power tool (e.g., increasing or decreasing speed or stopping the motor) in response to the detected material change. The object detection sensor may include, for example, an RF sensor, a capacitive sensor, a camera, a conductivity probe, or an ultrasound probe.
Claims20
A method for performing object detection in a power tool having a controller, a motor, and an output component coupled to the motor and defining an operating path of the power tool, the method comprising:
- transmitting a first radio-frequency (“RF”) signal having a first frequency;
- receiving a frequency response signal indicative of an object being proximate to or in the operating path of the power tool;
- generating an output signal based on the received frequency response signal;
- comparing the output signal to a plurality of predetermined frequency responses;
- selecting one of the plurality of predetermined frequency responses based on the comparison;
- determining a type of material for the object based on the selected one of the plurality of predetermined frequency responses;
- maintaining, based on the determined type of material of the object being a first type of material, power to the motor;
- and
- inhibiting, based on the determined type of material of the object being a second type of material, power to the motor,
- wherein the first type of material is different from the second type of material.
A method for performing object detection in a power tool having a controller, a motor, and an output component coupled to the motor and defining an operating path of the power tool, the method comprising:
- receiving a capacitance signal based on a capacitive field in the operating path of the power tool;
- generating an output signal based on the received capacitance signal;
- comparing the output signal to a plurality of predetermined capacitance thresholds or ranges;
- selecting one of the plurality of predetermined capacitance thresholds or ranges based on the comparison;
- determining a type of material of an object proximate to or in the operating path of the power tool based on the selected one of the plurality of predetermined capacitance thresholds or ranges;
- maintaining, based on the determined type of material of the object being a first type of material, power to the motor;
- and
- inhibiting, based on the determined type of material of the object being a second type of material, power to the motor,
- wherein the first type of material is different from the second type of material.
A method for performing object detection in a power tool having a controller, a motor, and an output component coupled to the motor and defining an operating path of the power tool, the method comprising:
- receiving a capacitance signal based on a capacitive field in the operating path of the power tool;
- generating an output signal indicative of a measured capacitance of an object being proximate to or in the operating path of the power tool;
- comparing the output signal to a plurality of capacitance ranges;
- maintaining an electrical current available to the motor when the measured capacitance is within a first capacitance range indicative of a first type of material;
- inhibiting the electrical current available to the motor when the measured capacitance is within second capacitance range indicative of a second type of material,
- wherein the first capacitance range is different from the second capacitance range, and
- wherein the first type of material is different from the second type of material.
Dependencies are inferred from the claim text.