GB2221330A

GB2221330A - Anti-theft alarm device

Info

Publication number: GB2221330A
Application number: GB8817872A
Authority: GB
Inventors: David Hoffmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-07-27
Filing date: 1988-07-27
Publication date: 1990-01-31
Also published as: GB8817872D0

Abstract

The device is suitable for preventing theft of re-usable metal kegs from outside licensed promises and comprises a cable 22, 23 adapted to be extended through the hand grips of a number of kegs, extended at either end to the inside of the building through appropriate access holes and connected, inside the building, at either end of the cable, with alarm circuitry. The cable comprises two mutually insulated conductors, preferably arranged coaxially, one of these conductors forming a continuous electrical connection between respective points in the alarm circuitry and the other conductors having, intermediate the ends of the cable, a deliberately contrived, concealed brake. The alarm circuitry is so arranged that the alarm may be set off by a thief simply breaking the cable or by a thief attempting to circumvent the alarm by electrically connecting the end parts of the cable before breaking the cable to remove the kegs. <IMAGE>

Description

DESCRIPTION OF INVENTION Title: "Anti-theft device" THIS INVENTION relates to an anti-theft device and is of particular, but not exclusive, utility as a device for use in deterring and detecting theft of empty beer kegs stored outside public houses for collection by brewer's lorries.

Draught beer is generally delivered by breweries to public houses or other licensed premises in re-fillable metal kegs, which, when they have been emptied are returned to the breweries for re-use. As such kegs are emptied at a public house, or the like, the empty kegs are generally, for convenience, stored outside the licensed premises concerned for collection by the brewer's lorries. Because the kegs have substantial scrap-metal value, large numbers of such kegs are stolen every year, at considerable loss to the brewers and/or to the public houses concerned.

It is an object of the present invention to provide an anti-theft device for discouraging or detecting such theft.

According to the invention there is provided an antitheft device comprising a cable having at least two mutually insulated conductors, alarm circuitry connected with the cable at one end and detachably connected with the cable at the other end, the arrangement being such that, when both ends of said cable are appropriately connected with sa d crcuitry, a first one of said conductors forms a cont-nuous electrical connection between respective points in said alarm circuitry, whilst a breac in electrical continuity is deliverately contrived in a second one of said conductors at a point intermediate the ends of the cable, the alarm circuitry being arranged to provide an alarm signal if either said first one of said conductors is severed intermediate the ends of the cable, or the parts of the other said conductor on opposite sides of said break are electrically connected, whereby the alarm may be set off by a thief simply breaking the cable or by a thief attempting to circumvent the alarm by electrically connecting said parts of the second conductor on either side of the break prior to breaking the cable.

Preferably, the cable is a co-axial cable, said first conductor being a central core and said second conductor comprising a conductive sheath surround said core.

An embodiment of the invention is described below by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a perspective view illustrating an antitheft device embodying the invention, and FIGURES 2 and 3 are diagrammatic enlarged scale views of portions of co-axial cable utilised in the device.

The device shown comprises alarm circuitry (not shown) housed in a housing 10, which may, for example, be secured to a wall inside a public house, in a part thereof not accessible to the public. The housing 10 affords two sockets for respective co-axial plugs 20, 21, provided at the ends of respective lengths 22, 23 of coaxial cable.

Unit is permanently connected to the electrical mains via cable 26. Alternatively, a batter mounted within housing 10 may power the unit.

Co-axial cable 22 has one of its ends fitted with a co-axial plug 20 so that the body of the plug is in contact with the braided screen 30. A further co-axial plug 25 is fitted to the opposite end of cable 22 but the braided screen is insulated from the body of the co-axial plug 25 at the other end of cable 22, for example with insulation tape 32 in such a manner that the fact that the screen 30 is not connected to the body of plug 25 is not evident from a visual inspection of the assembled plug and cable. The central core conductor 31 of cable 22 is electrically connected to the central pin of plug 20 and to the central pin of plug 25.

Co-axial cable 23 likewise has one of its ends fitted to the co-axial plug 21 so that the body of the plug is in electrical contact with the braided screen 30 and has its other end fitted to a co-axial socket 24 so that the braided screen is insulated from the body of co-axial socket 24, for example with insulation tape 32, again preferably in such a way that this fact is not evident from visual inspection of the assembled socket and cable. The central core conductor 31 of cable 23 is connected to the central pin of plug 21 and to the central conductor of socket 24.

The cables 22 and 23 extend from plugs 20 and 21, plugged into unit 10, to pass to the outside of the building through appropriate access holes drilled, for example, in a window frame. The cables 22 and 23 are then linked through the hand grips of a number of empty beer kegs and then plug 25 is connected to socket 24 so that the beer kegs are now captive in a closed loop.

The unit is switched on with a key-switch 27 incor prorated in housing 10. The stand-by condition of the alarm dez e s is ndcated b an LSD 3ht emi -. lode) 25 lighvlng up.

With the unit thus set, if the closed loop formed by the central conductors 31 of cables 22 and 23 and the central conductors of plug 25 and socket 24 is broken in any way the unit will immediately be triggered, sounding an audible alarm incorporated in the circuitry and housed within housing 10 and lighting up an LED 29 on the housing 10.

Furthermore the circuitry within housing 10 is so arranged that, if the unit has been set, it will be triggered if an electrical connection is established between the screen 30 in cable 22 and the screen 30 in cable 23, for example by a thief, attempting to circumvent the alarm device, driving a nail through the cables 22 and 23 to connect the conductors between the kegs and the alarm device, before separating the plug 25 from socket 24 or one of the cables 23, 22 further from the alarm device to allow removal of the kegs.

Once activated the alarm can only be stopped and the device re-set, with the key-switch 27.

Claims

LAINSi. -. -.

1. An anti-theft device comprising a cable having at least two mutually insulated conductors, alarm circuitry connected with the cable at one end and detachably connected with the cable at the other end, the arrangement being such that, when both ends of said cable are appropriately connected with said circuitry, a first one of said conductors forms a continuous electrical connection between respective points in said alarm circuitry, whilst a break in electrical continuity is deliberately contrived in a second one of said conductors at a point intermediate the ends of the cable, the alarm circuitry being arranged to provide an alarm signal if either said first one of said conductors is severed intermediate the ends of the cable, or the parts of the other said conductor on opposite sides of said break are electrically connected, whereby the alarm may be set off by a thief simply breaking the cable or by a thief attempting to circumvent the alarm by electrically connecting said parts of the second conductor on either side of the break prior to breaking the cable.

2. An anti-theft device according to claim 1 wherein the cable is a co-axial cable, said first conductor being a central core and said second conductor comprising a conductive sheath surrounding said core.

3. An anti-theft device substantially as hereinbefore described with reference to and as shown in the accompanying drawing.

4. Any novel feature or combination of features described herein.