RU2559697C2 - Intrusion indicator - Google Patents

Abstract

FIELD: physics, signalling.

SUBSTANCE: invention relates to electronic engineering, particularly to alarm systems, and can be used in developing methods and equipment for controlling access to a facility. The indicator has a housing which consists of two electrodes separated by a dielectric insert, which form a capacitive sensitive element which is electrically connected to a power supply, an indicative 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 which is installed on the housing of the device for protecting the sensitive element from interference.

EFFECT: low temperature dependence of the capacitive sensitive element and improved performance of the device.

5 cl, 3 dwg

Description

The invention relates to the field of electronic technology, in particular, to alarm systems, and can be used in the development of methods and means of access control to an object.

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 action 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, the presence of movable elements in the structure.

The task to which the claimed invention is directed is to create a universal device that saves information about the sealing procedure and information about attempts to intervene in a controlled object, eliminating the possibility of unauthorized replacement of the device with an identical one.

The technical result achieved by the claimed invention is to expand the functionality and scope of the device that records the fact of interference in a controlled object.

The solution to this problem is achieved by the fact that the proposed device for indicating interference, according to the invention, contains a housing with a protective cap made of dielectric material, and the protective cap is made in such a way that excludes the removal of the indicating device from the controlled object without removing the protective cap, the power source located inside the housing, an inductor and an electronics unit electrically connected to each other and connected to a capacitive sensitive element consisting of two electrodes of cylindrical shape, which is part of the device’s body, one of the electrodes being made with a profiled end part for connecting the intervention indication device with the mating profiled part of the object being monitored, separated by an electrically insulating insert, which is also part of the case. On the inner surface of the protective cap, structural elements are made that mesh with the reciprocal structural elements on the outer surface of one of the electrodes and ensure that the protective cap is secured from axial movement after being installed on the display device body, and these structural elements are made 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 the embodiment, an inner metal insert is installed inside the protective cap from the inlet end, so that when the protective cap is installed on the device’s body in the working position, the said insert does not guarantee overlapping the dielectric insert between the electrodes, while the height of the annular insert along the axis is selected from the condition oversize of the axis of the dielectric insert between the electrodes.

In an embodiment, an external or internal thread is made at the end of the electrode mating with the controlled object for docking with the controlled object.

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

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

The invention is illustrated by drawings, in which Fig. 1 shows a cross-sectional diagram of an embodiment of an indication device with an external threaded docking element, Fig. 2 shows an embodiment of a device with an internal threaded docking element, Fig. 3 shows a cross-sectional diagram of an embodiment of an indication device with a protective cap with an annular metal insert.

The display device comprises a housing consisting of a first electrode 1, a second electrode 2 and an intermediate insert 3 of electrically insulating material forming a capacitive sensitive element. At the first electrode 1, structural elements are made for fastening the seal to the controlled object. A power supply 4, an inductor 5, and an electronic unit 6 are installed inside the housing. A protective cap 7 is mounted on the display device body. In an embodiment, an inner metal insert 8 is installed inside the protective cap 7, from the input end side.

The device operates as follows.

The indicating device is fixed on the controlled object, then a protective cap 7 is installed on the device body.

If the protective cap 7 is removed, the sensitivity of the capacitive element consisting of electrode 1, electrode 2 sharply increases. When an object with a dielectric constant different from the dielectric constant is introduced into the sensitivity zone of the medium, the input capacitance of the sensitive element changes, and a pulse is generated that initiates recording on the fact of access indicating the date and time of access to the internal memory of the electronic unit 6. The presence of an induction communication interface provides POSSIBILITY data remotely to an external reader.

In the embodiment of the protective cap 7 with the inner annular insert 8 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 7.

Using the proposed technical solution will improve operational characteristics, reduce manufacturing costs and expand the scope of the intervention indication device.

Claims (5)

1. An intervention indication device, characterized in that it comprises a housing on which a protective cap of dielectric material is mounted, located inside the housing and electrically connected to each other by a power source, an inductor, an electronic information processing and storage unit, connected to a capacitive sensitive element consisting of of two electrodes that are part of the body of the display device, while one of the electrodes is made with a profiled end part for connecting the display device interferences with the return profiled part of the controlled object, separated by an electrically insulating insert, which is also part of the housing, and the protective cap is made in such a way that eliminates the possibility of removing the indicating device from the controlled object without removing the protective cap, while structural elements are made on the inner surface of the protective cap engaging with mating structural elements on the outer surface of one of the electrodes and providing f fixing the protective cap from axial movement after it is installed on the display device casing, and these structural elements are made in such a way that eliminates the removal of the display device from the controlled object when removing the protective cap. 2. The device according to claim 1, characterized in that an annular metal insert is installed inside the protective cap on the side of the inlet end, so that when the protective cap is installed on the device’s body in the working position, the said insert does not guarantee overlapping dielectric insert between the electrodes, the height of the annular insert along the axis is selected from the condition of exceeding the size along the axis of the dielectric insert between the electrodes. 3. The device according to any one of paragraphs. 1-2, characterized in that one of the electrodes is made with a profiled end part for connection with the mating profiled part of the controlled object 4. The device according to any one of paragraphs. 1-3, characterized in that on the end of the electrode, mating with the controlled object, made of external or internal thread for docking with the controlled object. 5. The device according to any one of paragraphs. 1-4, characterized in that the protective cap is threaded for connection with a controlled object.

Images