GB2130147A - Security collars - Google Patents

Abstract

A security collar 10 integrally formed of polypropylene is disclosed including: a pair of aligned generally concave walls 12a, 12b; a flexible strap (14) permitting the walls 12a, 12b to be manipulated around a component, such as nut (44), which needs protection against accidental actuation, or a deterrent against unauthorised actuation; complementary plugs 24 and sockets (26) for snap engagement with one another, the plugs 24 having double barbs, allowing some free travel within the sockets 26 and being frangibly connected to flange 22a; and rims 18a, 18b, 20a, 20b projecting from opposed side edges of at least one of the walls 12a, 12b to prevent displacement of the security collar 10 from the nut 44. <IMAGE>

Description

SPECIFICATION Security collars The present invention relates to security collars by which is meant collars to be fastened around the peripheries of components in such a manner that said collars must be broken or visibly damaged before said components can be actuated.

It is envisaged that the component will normally be a nut having peripheral drive surfaces.

The nut may for example control a critical valve setting or secure a guard which it would be dangerous to remove. In a typical application, a pair of nuts respectively connect inlet and outlet pipes to a fluid flow meter. A pair of security collars would here be used around the nuts to prevent the nuts being released, thereby preventing the inlet and outlet pipes being reversed to give a false reading on the meter. The component could however be anything which is to be protected against accidental actuation, or which needs a deterrent against unauthorised actuation. In this context a nut is actuated by being turned, but different components might be actuated in different ways.

An aim of the present invention is to provide a security collar which is easy and cheap to make as well as effective and reliable to use.

A security collar in accordance with the present invention comprises a one-piece plastics moulding presenting a pair of aligned generally concave wall members, connecting means extending between adjacent end portions of the wall members for permitting the wall members to be manipulated into the form of a collar around the periphery of a component, interlocking means carried by the other end portions of the wall members for snap engaging with one another, and retaining means projecting from opposed side edges of at least one of the wall members for preventing displacement of the collar from the component.

Preferably, the plastics material is polypropylene because it shows tampering by blanching where disturbed or stressed and it is resistant to being stuck together by adhesive after tampering.

Also preferably, the wall members will be of similar dimensions although one could be larger than the other, and their concavity will result from each of the wall members being arcuate rather than polygonal.

The connecting means may be formed as a flexible strap rather than a hinge. The ends of the strap may be set back from the ends of the wall members, and the wall members may be recessed on their outer surfaces to help accommodate the strap. The width of the strap may match or at least form a major part of the width of the wall members.

The interlocking means may be formed as a plug to be snap engaged in an opposed socket.

Indeed, there may be more than one complementary plug and socket, in which case each of the wall members may carry just plugs, or just sockets, or at least one of each of a plug and a socket. The interlocking means may be carried by flanges formed at the ends of the wall members.

The retaining means may be formed as a plurality of rims, each extending along the entire length of a respective side edge of a wall member, rather than as a series of spaced-apart tabs. The arrangement may be such that the retaining means project from opposite side edges of the same wall member, or from offset side edges of different wall members. Both of these possibilities are contemplated by saying that the retaining means projects from opposed side edges of at least one of the wall members. In an alternative arrangement the retaining means may project from all four of the side edges of the wall members. The retaining means may project from inner surfaces of the wall members to different extents depending on the particular application.

An important practical requirement of the security collar of the present invention is that there should be a visible indication of any tampering. With that in mind the interlocking means are preferably formed as at least one complementary plug and socket which incorporates one or more of the following three interrelated features.

Firstly, the plug is formed with a double barb for snap engagement with a double latch in the socket. This makes it extremely difficult to release the plug from the socket by tampering with a thin tool. Secondly, the length of the plug is such that, even in the snap engaged position, the plug can travel a small distance backwards and forwards in the socket. This means that the plug cannot just be stuck back in the socket after tampering because the plug would then not be able to move relatively to the socket. Thirdly, the plug is joined to the remainder of the wall member by a weakened area forming a frangible connection.

This means that any rough handling during tampering is likely to break the frangible connection.

In the preferred method of manufacture of the security collar of the present invention: the strength of the frangible connection can be readily adjusted; break-off areas can be provided to allow location in restricted spaces next to other components; identification codes can be marked directly; and mounting means may be formed to which other articles can be attached.

A security seal in accordance with the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:~ Figure 1 is a front perspective view from above and one end of the security collar as moulded; Figure 2 is a rear view; Figure 3 is an underneath view; Figures 4 to 6 are respectively front, end and plan views on an enlarged scale of one of the plugs; Figures 7 to 9 are respectively underneath, section on line X-X, and section on line Y-Y views on an enlarged scale of one of the sockets; Figure 10 is a front view in the closed position; and Figure 11 is a schematic half-section on line Z-Z showing the security collar in situ.

A particularly preferred security collar 10 in accordance with the present invention is shown in the accompanying drawings, the security collar 10 being moulded in one-piece of the plastics material polypropylene in the shape shown in Figures 1 to 9, with the shape adopted by the security collar 10 in use being shown in Figures 10 and 11.

The security collar 10 includes two substantially similar semi-cylindrical walls 1 2a, 1 2b whose adjacent end portions are connected by a flexible strap 14. Outer surfaces of the walls 1 2a, 1 2b are formed with recesses 1 6a, 1 6b to help accommodate the strap 14. Inner surfaces of the walls 1 2a, 1 2b are formed with rims 1 8a, 1 8b, 20a, 20b. In particular, the wall 1 2a has the rim 18a on one side edge with the rim 20a being on its opposite side edge. On the wall 1 2b, the rim 1 8b is aligned with the rim 1 8a and the rim 20b is aligned with the rim 20a.The other ends of the walls 1 2a, 1 2b have flanges 22a, 22b. The flange 22a carries a pair of plugs 24 whereas the flange 22b carries a complementary pair of sockets 26.

When the walls 1 2a, 1 2b are manipulated towards one another, in that sense causing the flexible strap 14 to straighten, the plugs 24 can snap engage in the sockets 26 to close the security collar 10. Apertures 28a, 28b in the flanges 22a, 22b are brought together and the walls 1 2a, 1 2b form a substantially complete cylinder. The rims 1 Sa, 1 8b form a ring at one end of the cylinder and the rims 20a, 20b form a ring of greater internal diameter at the other end of the cylinder.

Any attempt at tampering causes the polypropylene to blanch or to break.

The particular configuration of the plugs 24 and the sockets 26, which will now be described in detail with reference to Figures 4 to 9, makes successful tampering especially difficult.

Each of the plugs 24 is formed with an inclined arm 30 and a shoulder 32 which together act as a double barb. Each of the sockets 26 is formed with an inclined tooth 34 and a shoulder 36 which together act as a double latch. It will be clear that, as the plugs 24 are introduced into the sockets 26, the teeth 34 and to a lesser extent the arms 30 are resiliently deformed as they engage one another. The teeth 34 and the arms 30 snap back to their unstressed positions after the shoulders 32 have been advanced past the shoulders 36.

The spacing of the shoulder 32 on each plug 24 from the flange 22a is greater than the spacing of the shoulder 36 on each socket 26 from the flange 22b. This means that; even after the security collar 10 has been closed, the plugs 24 can be moved slightly within the sockets 26, to provide a visual indication that all is well.

The flange 22a is joined to each of the plugs 24 by frangible connections 38. The frangible connections are formed, during manufacture of the security collar 10, by positioning cores in the mould to form openings 40 in the flange 22a and radiused ends 42 for the plugs 24. Each of the plugs 24 is thus joined to the flange 22a by just two thin necks of the polypropylene constituting the frangible connections 38.

Advancing or retracting the positions of the cores in the mould will respectively weaken or strengthen the thin necks.

Similar weakened lines 46 are formed in the walls 1 2a, 1 2b by positioning strips in the mould to define a pair of break-off areas 48.

In use, as indicated schematically in Figure 11, the security collar 10 is closed around peripheral drive surfaces 42 of a nut 44. The rings formed by the rims 1 8a, 1 8b, 20a, 20b prevent displacement from the nut 44 and also prevent application of a box spanner to the peripheral drive surfaces 42.

Naturally, the walls 1 2a, 1 2b prevent direct application of a flat spanner to the peripheral drive surfaces 42.

The weakened lines 46 are provided to allow removal of one or both of the corresponding break-off areas 48 should that be desirable in a restricted space close to other components.

Indeed, reference to Figure 1 1 will show that the break-off area 48 has been removed from the wall 1 2b and the rim 20b to avoid fouling component part 50. The apertures 28a, 28b are provided to allow application of an identity tag or even a strap seal thereto should that be desirable in the particular circumstances.

Although the illustrated security collar is the currently preferred embodiment, it will be appreciated that many modifications are possible, for example the inclined arms 30 of the pair of the plugs 24 need not face in opposite directions.

Claims (10)

1. A security collar comprising a one-piece plastics mouldings presenting a pair of aligned generally concave wall members, connecting means extending between adjacent end portions of the wall members for permitting the wall members to be manipulated into the form of a collar around the periphery of a component, interlocking means carried by the other end portions of the wall members for snap engaging with one another, and retaining means projecting from opposed side edges of at least one of the wall members for preventing displacement of the collar from the component.

2. A security collar according to claim 1, in which the interlocking means is formed as at least one complementary plug and socket.

3. A security collar according to claim 2, in which the plug is formed with a double barb for snap engagement with a double latch in the socket.

4. A security collar according to claim 2 or claim 3, in which the length of the plug is such that, even in the snap engaged position, the plug can travel a small distance backwards and forwards in the socket.

5. A security collar according to any one of claims 2 to 4, in which the plug is joined to the remainder of the wall member by a weakened area forming a frangible connection.

6. A security collar according to any one of claims 2 to 5, in which there are two or more complementary plugs and sockets.

7. A security collar according to any preceding claim, in which the connecting means is formed as a flexible strap.

8. A security collar according to any preceding claim, in which the retaining means is formed as a plurality of rims, each extending along the entire length of a respective side edge of a wall member.

9. A security collar according to claim 8, in which at least one of the rims includes a break-off area to allow location of the security collar in a restricted space next to another component.

10. A security collar substantially as hereinbefore described with reference to the accompanying drawings.