Device for and method of preventing accidents in hand-operated machine tools due to tool jamming
First Claim
1. Device for preventing accidents caused by jamming a rotating tool (8) in hand operated machine tools (M), said machine tool (M) comprising an interrupter device (5,6) for interrupting the operation of a motor for driving said rotating tool (8) depending on the operating conditions of the machine tool (M) detected by a deflection sensor (1) in said machine tool (M), a computer unit (R) within said machine tool (M) connected to said deflection sensor (1) for converting measured values received from said deflection sensor into rotational movement values characterizing the operating conditions of the machine tool and for processing the rotation movement values according to presettable criteria by nonlinear signal processing to form accident probabilities, and a comparison device (14) connected to said interrupter device (5, 6), so that said comparison device generates a signal for activating said interrupter device (5, 6) when the accident probability determined by said computer unit (R) exceeds an adjustable threshold value.
1 Assignment
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Accused Products
Abstract
A device for and method of preventing accidents caused by jamming of a tool when working with hand-operated machine tools driving a rotating tool, especially hammer drills, is outfitted with an interrupter device for interrupting the action of the driving motor on the rotating tool depending on the operating state detected by a deflection sensor (1). The device includes a computer unit (R) in which a probability for an expected accident is determined from the sensor signals supplied by the deflection sensor (1), and in that the interrupter device (5, 6) can be activated when a preset accident probability is exceeded. In the method rotational movement values are determined from the measurement signals supplied by the deflection sensor (1), these rotational movement values are converted in a computer unit (R) by nonlinear logic operations to form accident probabilities and activating the interrupter device as soon as the estimated accident probability exceeds a preadjustable threshold value.
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Citations
20 Claims
- 1. Device for preventing accidents caused by jamming a rotating tool (8) in hand operated machine tools (M), said machine tool (M) comprising an interrupter device (5,6) for interrupting the operation of a motor for driving said rotating tool (8) depending on the operating conditions of the machine tool (M) detected by a deflection sensor (1) in said machine tool (M), a computer unit (R) within said machine tool (M) connected to said deflection sensor (1) for converting measured values received from said deflection sensor into rotational movement values characterizing the operating conditions of the machine tool and for processing the rotation movement values according to presettable criteria by nonlinear signal processing to form accident probabilities, and a comparison device (14) connected to said interrupter device (5, 6), so that said comparison device generates a signal for activating said interrupter device (5, 6) when the accident probability determined by said computer unit (R) exceeds an adjustable threshold value.
- 12. Method of preventing accidents caused by jamming a rotating tool (8) driven by a hand operated machine tool (M) and comprising an interrupter device (5, 6) in said machine tool for interrupting a rotational action on said rotating tool (8) depending on the operating state of the rotating tool detected by a deflection sensor (1) in said machine tool comprising the steps of determining rotational movement values characterizing the operating conditions of the rotating tool (8) obtained from measured values provided by said deflection sensor (1), and processing the rotational movement values in a computer unit (R) based on presettable criteria by nonlinear signal processing for forming accident probabilities, and activating said interrupter device (5, 6) as soon as the accident probability determined by the computer unit (R) exceeds an adjustable threshold value.
Specification