Method of and arrangement for preventing accidents during operation of a manually-operated machine tool with a rotatable toolbit
AssigneeHilti Aktiengesellschaft
InventorLino Guzzella
Life of this patent
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Abstract
A method of and an arrangement for preventing accidents during operation of a manually-operated machine tool having a rotatable toolbit and a drive motor for driving the toolbit, wherein an operational condition of the toolbit is determined with a rotational motion sensor, a time constant is selected, a maximum forecast rotational angle at an end of a time period determined by the selected time constant is calculated on a basis of a rotational motion signal generated by the sensor, and transmission of drive motion from the drive motor to the rotatable toolbit is interrupted as soon as the calculated, forecasted rotational angle exceeds a value of the maximum allowable rotational angle.
Claims20
A method of preventing accidents during operation of a manually-operated machine tool having a rotatable toolbit and a drive motor for driving the toolbit, said method comprising steps of:
- determining an operational condition of the toolbit with a rotational motion sensor;
- selecting a time constant;
- calculating, on a basis of a rotational motion signal generated by the sensor, a maximum forecast rotational angle at an end of a time period determined by the selected time constant;
- and
- interrupting transmission of drive motion from the drive motor to the rotatable toolbit as soon as the calculated, forecasted rotational angle exceeds a value of maximum allowable rotational angle.
An arrangement for preventing accidents during operation of a manually-operated machine tool having a rotatable toolbit and a drive motor for driving the toolbit, said arrangement comprising:
- means for interrupting transmission of drive motion from the drive motor to the toolbit;
- a rotational motion sensor for determining an operational condition of the toolbit;
- computer means for calculating, on a basis of a rotational motion signal generated by the sensor, a maximum forecast rotational angle at an end of a time period determined by a selected time constant;
- and
- an output interface for transmitting to the interrupting means an actuation signal generated by the computer means when the calculated, forecasted rotational angle exceeds a pre-determined maximum allowable rotational angle.
Dependencies are inferred from the claim text.