Method and device for reliably monitoring a closed position of two parts moveable relative to one another
First Claim
1. A device for reliably monitoring a closed position of two parts moveable relative to one another, the device comprising an actuator and a sensor each for mounting to one of the parts, the sensor comprising a receiver circuit having an inductor and a capacitor connected to one another for generating a defined receiver circuit signal when a distance between the sensor and the actuator is less than a predetermined switching distance, the sensor further comprising a detector circuit connected to the receiver circuit for providing an enable signal when the defined receiver circuit signal is present, and a switching element designed to selectively suppress the defined receiver circuit signal by electrically isolating the detector circuit from at least one of the inductor and the capacitor.
1 Assignment
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Accused Products
Abstract
A device for reliably monitoring a closed position of two parts which can move relative to one another has an actuator and a sensor. The device is particularly used for monitoring the closed position of a protective door installed for safeguarding a technical installation which operates in an automated fashion. The sensor has a receiver circuit at an input side, which circuit generates a defined receiver circuit signal when a switching distance between the sensor and the actuator is fallen short of. A detector circuit provides an enable signal when the defined receiver circuit signal is present. According to one aspect of the invention, a test element is provided for selectively suppressing the defined receiver circuit signal.
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Citations
12 Claims
- 1. A device for reliably monitoring a closed position of two parts moveable relative to one another, the device comprising an actuator and a sensor each for mounting to one of the parts, the sensor comprising a receiver circuit having an inductor and a capacitor connected to one another for generating a defined receiver circuit signal when a distance between the sensor and the actuator is less than a predetermined switching distance, the sensor further comprising a detector circuit connected to the receiver circuit for providing an enable signal when the defined receiver circuit signal is present, and a switching element designed to selectively suppress the defined receiver circuit signal by electrically isolating the detector circuit from at least one of the inductor and the capacitor.
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11. A sensor for detecting the presence of an actuator mounted to a first part that is moveable relative to a second part, the sensor being adapted to be mounted to the second part and comprising a receiver circuit having an inductor and a capacitor connected to one another for generating a defined receiver circuit signal when the actuator comes close to the sensor, comprising a detector circuit connected to the receiver circuit for providing an enable signal when the defined receiver circuit signal is present, and further comprising a switching element designed to selectively suppress the defined receiver circuit signal by electrically isolating the detector circuit from at least one of the inductor and the capacitor.
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12. A method for reliably monitoring a closed position of two parts moveable relative to one another, the method comprising the steps of:
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arranging an actuator on one of the parts, arranging a sensor having a receiver circuit comprising an inductor and a capacitor connected to one another on the other of the parts, generating a defined receiver circuit signal using the receiver circuit when the distance between the sensor and the actuator is less than a predetermined switching distance, generating an enable signal using a detector circuit if the defined receiver circuit signal is present, and when the defined receiver circuit signal is present, briefly suppressing the defined receiver circuit signal using a switching element for isolating the detector circuit from at least one of the inductor and the capacitor, and generating a monitoring message if the detector circuit does not react to the suppression of the defined receiver circuit signal.
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Specification