Power tool anti-kickback system with rotational rate sensor
First Claim
1. A method for initiating a protective response in a power tool having a rotary shaft and a rotary motion sensor, comprising:
- arranging the rotational motion sensor at a location in the power tool spatially separated from the rotary shaft and proximate to where a user grasps the tool;
monitoring rotational motion of the rotational motion sensor about a longitudinal axis of the rotary shaft using the rotational motion sensor disposed in the power tool;
determining rotational motion of the rotational motion sensor with respect to the longitudinal axis of the rotary shaft using a controller disposed in the power tool and based on input from the rotational motion sensor;
initiating a first protective operation based on the rotational motion determined by the controller; and
initiating a second protective operation based on the rotational motion determined by the controller, where the first protective operation is different than the second protective operation.
1 Assignment
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Accused Products
Abstract
A control system is provided for use in a power tool. The control system includes: a rotational rate sensor having a resonating mass and a controller electrically connected to the rotational rate sensor. The rotational rate sensor detects lateral displacement of the resonating mass and generates a signal indicative of the detected lateral displacement, such that the lateral displacement is directly proportional to a rotational speed at which the power tool rotates about an axis of the rotary shaft. Based on the generated signal, the controller initiates a protective operation to avoid further undesirable rotation of the power tool. The control scheme employed by the power tool may initiate different protective operations for different tool conditions.
135 Citations
14 Claims
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1. A method for initiating a protective response in a power tool having a rotary shaft and a rotary motion sensor, comprising:
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arranging the rotational motion sensor at a location in the power tool spatially separated from the rotary shaft and proximate to where a user grasps the tool; monitoring rotational motion of the rotational motion sensor about a longitudinal axis of the rotary shaft using the rotational motion sensor disposed in the power tool; determining rotational motion of the rotational motion sensor with respect to the longitudinal axis of the rotary shaft using a controller disposed in the power tool and based on input from the rotational motion sensor; initiating a first protective operation based on the rotational motion determined by the controller; and initiating a second protective operation based on the rotational motion determined by the controller, where the first protective operation is different than the second protective operation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for initiating a protective response in a power tool having a rotary shaft, comprising:
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monitoring rotational motion of the power tool about a longitudinal axis of the rotary shaft; determining an angular displacement of the power tool about the axis of the rotary shaft; initiating a first protective operation when the angular displacement exceeds a first threshold; and initiating a second protective operation when the angular displacement exceeds a second threshold which is greater than the first threshold, where the first protective operation is different than the second protective operation. - View Dependent Claims (11, 12, 13, 14)
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Specification