Safety mechanism for a rotary hammer
First Claim
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1. A method for controlling a power tool having a rotary shaft, comprising:
- disposing an inertial mass in a housing of the power tool, the inertial mass being freely rotatable about an axis of rotation and the axis of rotation being axially aligned with the rotary shaft;
monitoring rotational motion of the power tool in relation to the inertial mass during operation of the power tool; and
activating a protective operation based on the rotational motion of the power tool in relation to the inertial mass.
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Abstract
An improved method is provided for controlling a power tool having a rotary shaft. The method includes: disposing an inertial mass in a housing of the power tool, such that the inertial mass is freely rotatable about an axis of rotation which is axially aligned with the rotary shaft; monitoring rotational motion of the power tool in relation to the inertial mass during operation of the power tool; and activating a protective operation based on the rotational motion of the power tool in relation to the inertial mass.
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Citations
29 Claims
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1. A method for controlling a power tool having a rotary shaft, comprising:
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disposing an inertial mass in a housing of the power tool, the inertial mass being freely rotatable about an axis of rotation and the axis of rotation being axially aligned with the rotary shaft;
monitoring rotational motion of the power tool in relation to the inertial mass during operation of the power tool; and
activating a protective operation based on the rotational motion of the power tool in relation to the inertial mass. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for detecting a bit jam condition in a power tool having a rotary shaft, comprising:
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disposing an inertial mass in a housing of the power tool, the inertial mass being freely rotatable about an axis of rotation and the axis of rotation being axially aligned with the rotary shaft;
monitoring rotational motion of the housing of the power tool in relation to the inertial mass; and
determining when angular velocity of the rotational motion exceeds a predefined velocity threshold indicative of a bit jam condition. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method for detecting a bit jam condition in a power tool having a rotary shaft, comprising:
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disposing an inertial mass in a housing of the power tool, the inertial mass being freely rotatable about an axis of rotation and the axis of rotation being axially aligned with the rotary shaft;
monitoring rotational motion of the housing of the power tool in relation to the inertial mass; and
determining when rotational displacement of the rotational motion exceeds a predefined displacement threshold indicative of a bit jam condition. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A control system for a power tool having a motor drivably coupled to a rotary shaft to impart rotary motions thereto, comprising:
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an inertial mass disposed in a housing of the power tool, the inertial mass being freely rotatable about an axis of rotation and the axis of rotation being aligned axially with the rotary shaft;
at least one sensing element in fixed relation to the housing of the power tool and configured to detect rotational motion of the housing in relation to the inertial mass; and
a controller electrically connected to the at least one sensing element and operable to initiate a protective operation based on the detected rotational motions of the housing in relation to the inertial mass. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
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Specification