RU2559699C2 - Fastening means for detecting intrusion - Google Patents

Abstract

FIELD: physics, signalling.

SUBSTANCE: invention relates to electronic engineering, particularly to alarm systems, and is used as a device for controlling access to a facility. The fastening means has a housing which consists of two electrodes, one of which has a shaped end part for connecting to a reciprocal shaped part of the application object, separated by a dielectric insert, which form a capacitive sensitive element which is electrically connected to a power supply, an inductive communication interface coil and an electronic unit for measuring capacitance of the sensitive elements, processing and storing information, said components being located inside the housing and connected to each other, and a safety cap made of dielectric material, which is installed on the housing of the device for protecting the sensitive element from interference.

EFFECT: preventing unauthorised replacement of the fastening means with identical means and storing information on accessing attempts while reducing temperature dependence by excluding movable parts in the structure of the sensitive element.

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Description

The invention relates to the field of electronic technology, in particular to alarm systems, and can be used as a fastener with a function to control interference.

A device is known that contains a cylindrical case, on the external surface of which a thread is made for attaching this device to a controlled object, a power source, a capacitive sensitive element, a winding and a central processing unit (CPU) are electrically connected to each other. The CPU includes a microcontroller, a quartz resonator, a communication interface and a circuit for measuring the capacitance of the sensing element, which includes a resistor (US patent No. 6791465, publ. 04/18/2002, IPC F16B 41/00 G08B 21/00, F16B 31/02).

The disadvantages of this device are the need to pair it with a reader for transmitting data; the possibility of false positives due to the temperature dependence of the capacitive sensitive element.

A device is known, which is a cylindrical body in which are installed: a battery; a fixed electrode made in the form of a disk of ceramic material; movable electrode; induction interface winding, central processing unit (CPU), cover, upper nut, lower nut and disk springs. The movable electrode is made in the form of a cylinder, on the outer surface of which a groove is made. Belleville springs fixed in the groove are fixed with a lower nut. From the outer end of the movable electrode, a blind threaded hole is made for fastening the device to a controlled object. One of the end surfaces of the fixed electrode / ceramic disk is coated with silver sputtering. In the case, the disk is mounted in such a way that it is oriented towards the movable electrode by the bare side. The movable and fixed electrodes form a capacitive sensitive element (RF patent No. 2401460, publ. 10.10.2010, IPC: G08B 21/00, F16B 31/02, F16B 41/00 prototype).

The device operates as follows.

When the device is screwed onto the threaded rod of the controlled object, the disk springs are compressed and the air gap between the movable electrode and the ceramic disk / fixed electrode increases. When the device is unscrewed under the influence of cup springs, the air gap decreases, which leads to a change in the capacitance of the sensing element, recorded by the CPU as a fact of access to the object. Information about access facts can be transmitted remotely via an induction interface to an external reader.

The disadvantage of this device is the need for power pairing of the device with a controlled object to activate the sensing element, the presence of movable elements in the structure.

The task to which the claimed invention is directed is to create a fastening means that saves information about the installation procedure and information about attempts to access a controlled object, eliminating the possibility of unauthorized replacement of fastening means by an identical one.

The solution to this problem is achieved by the fact that the proposed fastening means for detecting unauthorized interference, according to the invention, contains a housing consisting of two electrodes, mainly cylindrical in shape, one of which is made with a profiled end part for connection with the mating profiled part of the mounting object, separated by a dielectric insert forming a capacitive sensing element connected to a power source located inside the housing and interconnected I, by a winding of the induction communication interface and an electronic unit for measuring the capacitance of the sensitive element, processing and storing information, a protective cap made of dielectric material, and the protective cap is made in such a way that eliminates the removal of fasteners from the controlled object without removing the protective cap. On the inner surface of the protective cap, structural elements are made that mesh with the reciprocal structural elements on the outer surface of the housing of the fastening means and ensure that the protective cap is prevented from axial movement after being installed on the housing of the fastening means, and these structural elements are designed in such a way that the indication device is removed from the controlled object when removing the protective cap. The thickness of the protective cap is selected from the condition of ensuring the required level of protection of the capacitive sensitive element from the effects of random interference.

In an embodiment, an annular metal insert is installed inside the protective cap from the side of its inlet end so that when the protective cap is mounted on the housing of the fastening means in the working position, the dielectric insert between the electrodes does not overlap the said metal insert with the height of the annular insert axis selected from the condition of exceeding the height of the dielectric insert between the electrodes.

In an embodiment, the protective cap is threaded for connection with the fastening object.

The technical result achieved by the claimed invention is the expansion of the functionality and scope of the fastening means with the function of the fact of access.

The use of a new design scheme of a capacitive sensitive element, namely, the implementation of the electrodes as housing elements of the fastening means, allows to reduce the dimensions of the fastening means, to exclude movable elements in the structure, to simplify the design of the fastening means, to reduce the cost of its manufacture.

The invention is illustrated by drawings, in which Fig. 1 shows a cross-sectional diagram of an embodiment of fastening means with a connecting element with an external thread, Fig. 2 shows an embodiment of fastening means with a connecting element with an external thread, and Fig. 3 shows a cross-sectional diagram of an embodiment versions of the indicating device with a protective cap with an annular metal insert.

The fastening means comprises a housing consisting of a lower electrode 1, a head electrode 2 and an intermediate insert 3 of electrically insulating material forming a capacitive sensitive element. At the bottom electrode 1, structural elements are made for coupling the fastening means at the application 4. The power supply 5, the inductor 6 and the electronic unit 7 are installed inside the housing. The protective cap 8 is installed on the fastening housing. In the embodiment, the protective cap 8 is inside, from the side the lead end mounted ring metal insert 9.

Fixing means works as follows.

The fastening means is fixed on the object of application 4, a protective cap 8 is installed on the body of the fastening means.

When removing the protective cap 8, the sensitivity of the capacitive element sharply increases. If an object with a dielectric constant other than the dielectric constant of the medium is introduced into the sensitivity zone, the input capacitance of the sensitive element changes, a pulse is generated that initiates a record of the fact of access with the date and time of access to the internal memory of the electronic unit 7. Presence of an induction interface Communication provides the ability to transmit data remotely to an external reader.

In the embodiment of the protective cap 8 with the inner ring 9 of metal material, the formation of a pulse initiating a record of the fact of access occurs already at the time of removal of the protective cap 8.

Using the proposed technical solution will improve operational characteristics, reduce manufacturing costs and expand the scope of application of fasteners.

Claims (4)

1. A fastening means for detecting unauthorized interference, characterized in that it contains an external remote reading device, a housing made of a cylindrical shape, including two electrodes, one of the electrodes being made with a profiled end part for connection with a mating profiled part of the controlled object, separated by a dielectric an insert forming a capacitive sensing element connected to a source located inside the housing and interconnected power supply, a winding of the induction communication interface and an electronic unit for measuring the capacitance of the sensing element, processing and storing information, a protective cap made of dielectric material mounted on the housing and eliminating the possibility of removing fasteners from the controlled object without removing the protective cap, and on the inner surface of the protective cap are made elements engaged with mating structural elements on the outer surface of the housing and providing ksatsiyu protective cap from axial movement once installed on the sensor body, said structural elements are designed in such a way that a high priority remove the protective cap from the housing the mounting means to remove the sensor from the controlled object. 2. The fastening means according to claim 1, characterized in that an annular metal insert is installed inside the protective cap from the side of its inlet end so that when the protective cap is installed on the sensor body in the working position, the said insert does not guarantee overlapping dielectric insert between the electrodes, while the height of the annular insert along the axis is selected from the condition of exceeding the height of the dielectric insert between the electrodes. 3. The fastener according to any one of paragraphs. 1, and 2, characterized in that at the end of the electrode mating with the controlled object, made of external or internal thread for docking with the controlled object. 4. Fastening means according to any one of paragraphs. 1 and 2, characterized in that the protective cap is threaded for connection with a controlled object.

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