Rotary electrical hand-tool device and startup safety routine
AssigneeHilti Aktiengesellschaft
InventorsPeter Hellmann, Guido Werdun, Michael Reiner
Life of this patent
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Abstract
An electrical hand-tool device and start-up safety routine protecting against start-up blockages, in which an electrical motor is connected, for a short time span (T0), with the current supply at a determinable resistance. At least one of a limit value (αG) and a shut-off point in time (tA) is determined, for the safety routine in the event of tool blockage, using a measurement of the angle of rotation (φ) of the rotor taken over the time span (T0) dependent on the start-up behavior of a rotor in the time span (T0).
Claims9
A process for a start-up safety routine of an electrical hand-tool that produces at least one direction of rotation and comprises an electrical motor and a safety device, wherein the safety device is actuated by a microcontroller upon exceeding a limit value (αG) and interrupts the transmission of the torque between a tool and the electrical motor;
- the process comprising the steps of connecting the electrical motor to the current supply, for a short time period (T0), using one of a fixed effective impedance and a resistance determined by the microcontroller;
- measuring, via the microcontroller, the angle of rotation (φ(t)) of the rotor using means for the determination of one of the angle of rotation (φ(t)) and the speed over the time period (T0);
- calculating, via the microprocessor, one of the angular acceleration of the rotor and a value dependent on the angular acceleration of the rotor and;
- ascertaining from one of the angular acceleration of the rotor and a value dependent on the angular acceleration of the rotor at least one of the limit value (αG) and the shut-off point in time (tA) using a projection readable by the microcontroller
An electrical hand-tool device protecting against start-up blockages comprising an electrical motor for the production of at least one rotational movement and a safety device actuated by a microcontroller in the event of overrun for interruption of the transmission of the torque between a tool and the electrical motor, wherein the microcontroller is connected to means for the determination of one of the angle of rotation and speed and, wherein the microcontroller is connected to means for switching the electrical motor to the current supply using an effective impedance.
Dependencies are inferred from the claim text.