GB2196056A

GB2196056A - Security device

Info

Publication number: GB2196056A
Application number: GB08624215A
Authority: GB
Inventors: Kenneth Strefford; Terry Morley; Rodger Haird Hemington
Original assignee: Merseyside and North Wales Electricity Board
Current assignee: Merseyside and North Wales Electricity Board
Priority date: 1986-10-09
Filing date: 1986-10-09
Publication date: 1988-04-20
Anticipated expiration: 2006-10-09
Also published as: GB2196056B; GB8624215D0

Abstract

A security device for a cover, for example, an electric meter installation is in the form of a transparent cover (14) which fits over the installation. The cover is secured to a backboard (16) by means of four screws (18) passing through the corner of the cover, and is also provided with a pivotally mounted arm (52) on the undersurface, which, when the cover is in position over the installation, is pivotable behind a metallic bar (20) which is attached to the backboard (16), by means of a magnetic portion (58) on the end thereof. When the cover is removed, the arm, which is made of a frangible material, breaks, thus indicating that the cover has been removed. Once the arm has been pivoted behind the metallic bar (20), it cannot be moved out of position, due to the alignment of two recesses in the arm and its associated pivot (38a, Fig. 3), such that a lug (62) extends into both apertures, thereby preventing any further pivoting of the arm. The device is also provided with a plurality of guides (28), which ensure that the cover may only be removed by displacing it substantially perpendicularly to the plane of the backboard (16). <IMAGE>

Description

SPECIFICATION Security device The present invention relates to a security device, and in particular, but not exclusively, to a security device for indicating when an installation has been tampered with.

Certain installations, for example, electricity supply meters, are prone to illegal interference from fraudulent customers. In the case of electricity supply meters, it is known for fraudulent customers to attach a device to the electric cables adjacent to the meter such that the meter will run backwards, and hence the meter will record a smaller amount of electricity than has actually been supplied. Where a coin operated meter is fitted, the installation is further prone to theft of the money deposited in the meter. in both cases, the installation is closed, and is secured with a lead seal which must be broken if the installation is to be opened.However, it has been found possible to remove the seal from the installation, use the installation fraudulently and to replace the seal using illegal techniques and/or illegally obtained sealing pliers, so that it would appear that the meter has not been interfered with.

It is thus highly desirable to provide a device which effectively seals an installation such as an electrical meter installation, yet which when it is broken cannot be reformed, and hence will show that the installation has been tampered with.

In accordance with the present invention, there is provided a security device for an installation, the device comprising a member fixed relative to the installation, a cover adapted to at least partially cover said installation and said fixed member, and securing means attached to one of the said cover and said fixed member, said securing means being movable to a position in which movement of the securing means is restricted by a portion of the other of the said cover and said fixed member.

In one embodiment, the securing means is movable to a second position in which movement of the securing means is restricted by a portion of the other of the said cover and said fixed member, from a first position in which the movement of the securing means is not restricted by the other of said cover and said fixed member.

Preferably, the securing means comprises at least one first portion fixed to one of the said cover and said fixed member, and a second portion movable relative to the fixed portion.

In a preferred embodiment, the securing means may be held fixedly in the second position. This may be achieved by providing a recess in each of the first and second portions and a movable locking member in one of the recesses. Movement of the second portion relative to the first preferably aligns the recesses and allows the movable locking member to engage in both recesses. The movable locking member may be movable into the other aligned recess gravitationally. There may be a plurality of recesses in the first and/or second member. This allows the security device to be used in a plurality of orientations.

In a preferred embodiment, the second portion is movable magnetically. This may be done by providing a magnetic or magnetisable portion on the second portion, which, by cooperation with a magnetic or magnetisable portion controlled by an operator, may be used to move the second portion between the first position and the second position. Preferably, the movable locking member is non-magnetic and non-magnetisable.

In a preferred embodiment, the first portion comprises a pivot and the second portion comprises a pivotally mounted arm. Preferably, the second portion comprises a breakable, or frangible, material such as glass or plastics, e.g. polycarbonate, acrylic or styrene.

There may be a plurality of first portions, and the second portion may be releasably attachable to the or each first portion. If a plurality of first portions is provided, the second portion may be shaped to engage with one or more of the other first portions.

There may be means for restricting the direction in which the cover may be removed.

Preferably, the means allow the cover to be removed in substantially one direction only.

The means may comprise guides into which at least a portion of the cover fits when it is covering the installation. Preferably, the guides are fixed relative to the installation. The guides may comprise one or more elongate recesses aligned substantially in the direction in which it is desired to make the cover removable. The recesses may comprise a portion of a conduit, through which conduit the space enclosed by the cover may communicate with the exterior.

Alternatively, the cover may comprise upper and lower portions, and the lower portion may have a recess into which the upper portion fits, such that the upper portion may only be removed in a preferred direction.

The installation may be a meter for metering the electrical supply.

By way of example only, specific embodiments of the present invention will now be described, with reference to the accompanying drawings, in which:~ Figure 1 is a perspective view of an electricity meter fitted with a security device according to a first embodiment of the present invention; Figure 2 is a detailed perspective view of a portion of the device shown in Fig. 1; Figure 3 is an exploded cross-sectional side elevational view of the security device according to the first embodiment of the present invention; Figures 4 and 4b are detailed cross sections of the device of Fig. 3, in an unlocked and a locked position respectively; Figure 5 is a perspective view of an electricity meter fitted with a security device according to a second embodiment of the present invention; and Figure 6 is a cross-section-of an electricity meter fitted with a security device according to a third aspect of the present invention.

Referring firstly to Fig. 1, an electrical installation comprises an electric meter 10, and a main fuse box 12. The installation is enclosed in a transparent plastics case 14, which is attached to a mounting board 16 on a wall, on which board 16 the installation is mounted, by means of four screws 18 positioned at the corners of the casing. Also attached to the board 16, is a trapezoidal metal band 20 with the longer of its two parallel sides securely attached to board 16. A cover screw passes through a hole in the cover 14 and is screwed into a correspondingly threaded hole in the upper portion of the metal band 20. The cover screw is used in conjunction with a cap seating, and a destruct cap, to form a seal 22 which is already known in the art, and will not be described hereinafter.

An electrical supply lead 24 leads from the mains to the installation, and two cables 26 lead from the installation to form the electrical supply of the house, The cables 24, 26 pass through conduit devices 28, which are screwed to the base 16 through holes in flanges 30, which flanges are positioned inside the casing 14 in use. One conduit 28 is iilustrated in detail in Fig. 2. The conduit is provided with a connecting hole 32 for each cable passing therethrough, the connecting hole being spaced so that, in use, it will abut the cable tightly. On three faces of the conduit 28 there is a locating groove 34. The cover 14 is shaped so that it abuts the base of the groove 34 when in position on the board 16, the parallel walls 36 which define the base overlapping the opposed faces of the cover 14 in the region of the conduit 28.The parallel walls 36 ensure that the cover must be removed substantially perpendicularly to the plane of the board 16, the importance of which will be apparent hereinafter.

Moulded to the inside of the upper face of the cover 14 are two lugs 38a and 38b. The lugs comprise a thicker cylindrical portion 40 adjacent to the cover 14 and a narrower cylindrical portion 42, and are internally threaded.

As best seen in Figs. 4a and 4b, which are detail cross-sections, each portion 40 is also provided with two blind bores 46a, 46b. A sealing arm 48, made from acrylic, comprises an annular head 50 shaped to fit pivotally over either of the lugs 38a, 38b, and a frangi ble laminar portion 52 which-is designed to have a breaking strain of approximately 100 ber 52 remote from the annular portion 50 is provided with a recess 54 in such a position that when the annular member 50 is pivotally mounted on one of the lugs 38a, 38b, the recess 54 can be positioned around the other of the lugs 38a, 38b. The front face of the frangible member 52 is provided with a paper seal which is destroyed when the frangible member is broken.The sealing arm 48 may be releasably and pivotally held in position over one of the lugs 38a, 38b, by means of a screw 56 which is insertable into the threaded bore of the lug 38a, and holds a washer which, in use, abuts the annular portion 50 of the locking arm and holds it in position on the lug 38a, 38b. The end of the arm 52 remote from the annular portion is provided with a steel portion 58 which is securely attached to the arm 52, e.g. by glueing.

As best seen in Figs. 4a and 4b, the annular portion 50 is provided with two blind bores 60a, 60b, which are angularly spaced by 900. One of the blind bores 60, in the embodiment illustrated the blind bore 60a diametrically opposite the portion 52, houses a cylindrical brass slug 62. The other bore 60b is used if the installation is used in an orientation 900 to that illustrated.

In use, the conduits 28 are fixed in position over the cables 24, 26, and are secured to the board 16, and the cover 14 is positioned over the installation, ensuring that those portions of the cover adjacent to the conduits 28 are seated in the grooves 34 of the conduits 28. At this point, it is important that the sealing device 48 is in the orientation shown in Fig. 4a, i.e. in a position 1800 opposite to that illustrated in Fig. 1, or preferably slightly more than 1800 such that the arm 52 rests against the side wall of the cover 14 or a lug (not illustrated) moulded on the undersurface of the cover.In this configuration, as best seen in Fig. 4a, the blind bore 46a of the lug 38a and the blind bore 60a of the annular portion 50, which contains the slug 62, are substantially diametrically opposed, and the device 48 may pivot freely about the lug 42a.

The cover is secured by means of the screws 18, and by means of the seal 22, as was previously described. A person affixing the cover 14 pivots the arm 52 about the lug 38a by means of a magnet (not illustrated) which he places opposite the steel portion 58 on the arm 52, and by means of which he swings the arm 52 around until the recess 54 engages with the other of the lugs 38b. In practice, it is found that it is necessary only to pivot the arm over centre, when the weight of the arm will cause the arm to pivot the rest of the way and engage with the lug 38b. It will be seen from Figs. 1 and 3 that the arm 52 engages behind the metal band 20. It will also be seen from Fig. 4b that when the arm has pivoted 1800 from the position shown in aligned, and the brass slug 62 moves gravitationally downwards into the blind bore 46a.

The depth of the blind bore 46a is smaller than the length of the brass slug 62, so that the slug 62 extends into both the bores 46a and 60a, thus preventing the arm from pivoting in either direction. Thus, when the arm is pivoted to the position shown in Figs. 1 and 4b, such that it lies behind the metal band 20, it is fixed in position.

Any attempt to remove the cover, for example by removing screws 18 and the seal 22 and pulling the cover away from the board 16 will result in the arm 52, and the seal thereon, being broken, thus indicating to an authorised inspector that the installation has been tampered with. It will be noted that the channels 34 in the conduits 28 constrain the cover 14 to be moved in a direction substantially perpendicular to the board 16, at least until the cover 14 is clear of the conduits 28, so that it is not possible to slide the cover upwardly and so remove the cover 14 without damaging the seal 48.

Any attempt to pivot the seal to the position shown in Fig. 4a is thwarted by the engagement of the slug 62 in the aligned blind bores 46a and 60a. Furthermore, since the slug 62 is brass and is therefore non-magnetic, it is not possible to unlock the seal by moving the slug upwardly into bore 60a with the aid of a magnet, and pivot the seal 48 clockwise using another magnet.

The layout of an installation may be different from that illustrated. For example, it may be of such a configuration that it is necessary to fit a cover in an orientation substantially 900 in a clockwise direction to that of Fig. 1.

In this case, the slug 62 would initially be positioned in the blind bore 60b of the annular portion 50, and the initial orientation of the arm 52 would be substantially horizontal, or slightly lower than horizontal, resting on the wall of the cover 14. The arm would then be pivoted anticlockwise as before, to engage the arm 52 behind the metal band 20 and to engage the recess 54 with the other lug 38b. It is sometimes found in this case that the slug 62 fouls on the recess 46a on its movement towards the recess 46b, and if the situation demands it, the annular portion 50 may be pivotally mounted on the other lugs 38b, which has only one recess 46b and no recess 46a, and the recess 54 would, in the sealing position of the arm 52, engage with the lug 38a. By appropriate orientation of the arm 52, it may be rotatable clockwise or anticlockwise when pivotally mounted on lug 38b.

A second embodiment of the present invention is illustrated in Fig. 5. This is generally similar to the first embodiment, illustrated in Fig. 1, and like parts are denoted by like reference numerals. It differs from the first embodiment in that the mounting lug 38a of the first embodiment is replaced with a mounting lug (not visible) positioned on the undersurface of the upper portion of the metal band 20, on' which lug the sealing arm 48 is pivotally mounted.

In order to provide the sealing action, the arm 48, in its locked position (i.e. corresponding to the position of Fig. 4b of the first embodiment), engages in the channel of a Ushaped channel member 64 which is fixed by one of its faces to the underside of the upper face of the cover 14. The engagement of the arm 48 with the channel of the member 64 results in breakage of the frangible arm 48 if the cover is removed in a direction perpendicular to the plane of the mounting board 16.

As in the first embodiment, conduits 28 are provided so that the cover can only be removed in a direction substantially perpendicular to the plane of the mounting board 16.

In a further embodiment, illustrated in Fig. 6, the plastics case 14 comprises an upper portion 14a and a lower portion 14b. The lower portion 14b is in the form of a rectangular ring which is attached to the mounting board 16 by means of screws passing through an inwardly extending flange 17 which extends around the interior perimeter of the lower portion 14b. The end of the lower portion 14b remote from the mouting board 16 is provided with a groove 19 around the whole of its periphery, in which the upper portion 14a may be seated. Once seated in the groove, the upper portion 14a, which is otherwise identical to the case 14 of the previous embodiments, is secured as before.

This embodiment has the advantages that all the fixing screws are positioned inside the case 14 and the case may be ventilated without serious security risk, by means of one or more apertures 21. Furthermore, the groove 19, which replaces the guide 28 of the first embodiment, provides a guide around the whole of the periphery, and ensures that the case must be removed substantially perpendicularly to the plane of the board 16. The peripheral groove also limits the risk of bypassing the latch by tiling the cover, since the whole of the upper portion 14a must be removed vertically from the groove if access is to be gained to the installation.

Claims

1. A security device for an installation, the device comprising a member fixed relative to the installation, a cover adapted to at least partially cover said installation and said fixed member, and securing means attached to one of the said cover and said fixed member, said securing means being movable to a position in which movement of the securing means is restricted by a portion of thye other of the said cover and said fixed member.

2. A device as claimed in claim 1, wherein the securing means is movable to a second position in which movement of the securing means is restricted by a portion of the other of the said cover and said fixed member, from a first position in which the movement of the securing means is not restricted by the other of said cover and said fixed member.

3. A device as claimed in claim 1 or claim 2, wherein the securing means comprises at least one first portion affixed to one of the said cover and said fixed member, and a second portion movable relative to the fixed portion.

4. A device as claimed in any of claims 1 to 3, wherein the securing means is held fixedly in the second position.

5. A device as claimed in claim 4, when appendant to claim 3, comprising a recess in each of the first and second portions and a movable locking member in one of the recesses, wherein movement of the second portion relative to the first portion aligns the recesses and allows the movable locking member to engage in both recesses.

6. A device as claimed in claim 5, wherein the movable locking member is movable into the other aligned recess gravitationally.

7. A device as claimed in claim 5 or claim 6, comprising a plurality of recesses in the first and/or second member.

8. A device as claimed in any of claims 5 to 7, wherein the movable locking member is non-magnetic and non-magnetizable.

9. A device as claimed in claim 3 or any of claims 4 to 8 when appendant to claim 3, wherein the second portion is movable magnetically.

10. A device as claimed in claim 9, wherein the second portion comprises a magnetic or magnetizable portion.

11. A device as claimed in claim 3, or any of claims 4 to 10 when appendant to claim 3, wherein the first portion comprises a pivot and the second portion comprises a pivotally mounted arm.

12. A device as claimed in claim 11, wherein the second portion comprises a breakable or frangible material.

13. A device as claimed in claim 3, or any of claims 4 to 12 when appendant to claim 3, comprising a plurality of first portions, the second portion being releasably attachable to a plurality of first portions.

14. A device as claimed in any of claims 1 to 13, comprising means for restricting the direction in which the cover is removable.

15. A device as claimed in claim 14, wherein the means comprise guides into which at least a portion of the cover fits when it is covering the installation.

16. A device as claimed in claim 15, wherein the guides comprise one or more elongate recesses aligned substantially in the direction in which it is desired to make the cover removable.

17. A device as claimed in claim 16, wherein the recesses comprise a portion of a conduit, through which conduit the space enclosed by the cover may communicate with the exterior.

18. A device as claimed in any of claims 14 to 16, wherein the cover comprises upper and lower portions, and the lower portion has a recess into which the upper portion fits, such that the upper portion may only be removed in a preferred direction.

19. A security device for an installation, substantially as herein described with reference to, and as illustrated in, Figs. 1 to 4, Figs. 1 to 4 as modified by Fig. 5 and/or Fig.

6 of the accompanying drawings.