Microcontroller for and a method of controlling operation of the safety clutch of a hand-held electric power tool
AssigneeHilti Aktiengesellschaft
InventorsRoland Schaer, Hans Boni
Life of this patent
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Abstract
A microcontroller for controlling operation of a safety clutch of a handheld electrical power tool and which is arranged in a force transmitting chain of the tool, with the microcontroller including a unit (2,5,4;8) for processing at least one parameter of the power tool and for outputting a resulting parameter in form of a calculated torque (M1), and a control unit (7) for comparing an actually measured torque (M) with the calculated torque (M1), and for outputting a control signal (θ) when a difference between the actually measured and calculated torques exceeds a predetermined threshold.
Claims8
A microcontroller for controlling operation of a safety clutch of a hand-held electrical power tool and which is arranged in a force transmitting chain of the tool, the microcontroller comprising means (2,5,4;8) for processing at least one parameter of the power tool and for outputting a resulting parameter in form of a calculated torque (M1);
- and a control unit (7) for comparing an actually measured torque (M), which is inputted in the control unit (7) as a first input parameter, with the calculated torque (M1), which is inputted into the control unit (7) as a second input parameter, and for outputting a control signal (θ) when a difference between the actually measured and calculated torques exceeds a predetermined threshold.
A method of controlling operation of an electrically controlled safety clutch of a hand-held electrical power tool and arranged in a force transmitting chain of the tool, the method comprising the steps of one of transforming an input current (I) of a tool electromotor, by using a motor diagram (3) locally into a calculated torque (M1) and transforming an electrically filtered actually measured torque (M) into a locally calculated torque (M1);
- comparing a difference (Δ) between the actually measured torque (M) and the calculated torque (M1) with a predetermined threshold value;
- and outputting a control signal (θ) for actuating the safety clutch in response to the difference (Δ) between the actually measured and calculated torques (M, M1) exceeding the predetermined threshold value.
Dependencies are inferred from the claim text.