GB2265114A - Tamper-proof security seal with detent rotatable in housing - Google Patents

Abstract

A security seal, of the kind intended to provide physical evidence of tampering, includes a hollow housing (3) containing a detent (2) comprising collar (10) and three flexible fingers (11), and a flexible strap (5) or bar (4) having one end connected to the housing (3). Abutment tooth (7) is provided on the other end of the strap (5) or bar (4) and is insertable through an opening (21) in the housing (3) to co-operate with the detent (2) and thereby form the seal into a closed loop. Cooperation between the abutment tooth (7) and the detent (2) is such that withdrawal of the abutment tooth (7) from the housing (3) is prevented. The detent (2) is formed separate from the housing (3) and is rotatably mounted in the housing (3). Step (16) and cap (10) serve to retain the detent (2) in the housing (3). The detent (2) may be formed of a harder plastics material than the main component (1) and may have a higher melting point. Ultrasonic welding may be used to secure cap (9). <IMAGE>

Description

SECURITY DEVICES This invention relates to security devices and particularly to security devices which provide observable evidence of improper access to or tampering with whatever is intended to be protected thereby. Such security devices typically cannot be breached without destruction or partial destruction thereof, and it is that characteristic which provides visible evidence of the breach.

Security devices of the foregoing kind are wellknown and are used for a variety of purposes. They may provide high level or low level security depending upon the use situation. One typical use is to protect cash bags and document pouches against unauthorised access or tampering and it will be convenient to hereinafter describe the invention with particular reference to that example use.

Most bag or pouch seals are arranged either to encircle the neck or mouth of the bag, or to pass through apertures in the bag walls. Some bags are held closed by a closure, and that closure may need to be protected by a security seal if improper access to or tampering with the bag is to be avoided. The closure may take various forms.

For example, it may be a zip fastener, or it may be a rigid stud having a shank, a head at one end of the shank and a cap removably attached to the opposite end of the shank.

Security seals for any one of the foregoing applications generally include a flexible strap or bar which is insertable into a hollow housing and which has at least one tooth or other abutment formed thereon. The hollow housing includes detent means which co-acts with the tooth on the strap or bar so as to resist withdrawal of the strap or bar out of the housing. That is, the strap or bar can be moved through the housing in one direction, but not the reverse direction.

It has been found that seals of the foregoing kind can be tampered with before they are used so that they do not seal effectively. In particular, they can be modified in a manner which is not observable by casual inspection, and which enables the seal to be broken and reapplied without leaving visible signs of that activity.

According to the present invention, however, a security device includes a hollow housing, an entrance to the interior of said housing, detent means located within said housing and abutment means insertable into said housing through said entrance and being co-operable with said detent means when so inserted so as to be thereby held against withdrawal from said housing through said entrance, said detent means being movable relatively to said housing, and retaining means holding said detent means against removal from said housing.

In a preferred arrangement, the detent means is free to rotate relatively to the housing about an axis which is substantially coincident with the axis of a passage extending at least part way through the housing and which is the passage into which the abutment means is moved to effect closure of the security device.

The detent means preferably includes a plurality of flexible fingers which are located around the aforementioned passage and which are relatively long. Long fingers minimise the force necessary to push the abutment means through the passage against the obstruction formed by the detent means, and also make it difficult to tamper with the detent means as hereinafter described.

Two security devices, in accordance with the present invention, will now be described in greater detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a first security seal embodying the present invention, showing the seal in the as-manufactured condition as distinct from the ready-to-use condition; Figure 2 is a side view of the seal shown in Figure 1 again showing the seal in the as-manufactured condition; Figure 3 is an enlarged cross-sectional view of just the detent means taken along the line III-III of Figure 1; Figure 4 is an enlarged cross-sectional view of just the detent means taken along the line IV-IV of Figure 2; Figure 5 is an enlarged cross-sectional view taken along the line V-V of Figure 1 but showing the detent means located within the hollow housing;; Figure 6 is a view similar to Figure 5 but showing the seal in the ready-to-use condition; Figure 7 is a side view similar to Figure 6 but showing the abutment means inserted into the hollow housing; Figure 8 is a cross-sectional view taken along the line VIII-VIII of Figure 7; Figure 9 is a side view of a second security seal embodying the present invention; Figure 10 is an underplan view of the seal shown in Figure 9; and Figure 11 is an enlarged cross-sectional view taken along the line XI-XI of Figure 10.

The security seal shown in Figures 1 to 8 is composed of two separately formed pieces 1 and 2, each of which is preferably formed of a suitable plastics material. The piece 1 comprises the main component of the seal, and the piece 2 forms an inner detent part which is intended to be located within the main component of the seal.

In the particular construction shown, the main component 1 includes a housing body 3, a locking bar 4, and means connecting the body 3 to the bar 4. That connecting means may, as shown, comprise a flexible strap 5 which is connected to one end of the bar 4 through a tab 6. The body 3 is attached to the end of the strap 5 remote from the tab 6..

The bar 4 comprises or includes abutment means which functions as hereinafter described, and in the example shown that abutment means is in the form of a locking tooth 7. The tooth 7 is provided at the end of the bar 4 which is remote from the tab 6 and can have any appropriate configuration. As shown in Figure 1, the tooth 7 is formed by a head section 8 which is connected to the bar 4 through a reduced neck 9. The head section 8 may be tapered as shown to facilitate insertion into the housing body 3 as hereinafter described, and an abrupt end face 8a of the head section 8 functions as the operative substantially transverse abutment surface of the locking tooth 7 as also hereinafter described.

The part 2 includes or comprises the detent means of the seal and may be formed of a plastics material different from that used for the main component 1. In particular, the part 2 may be formed of a harder plastics material and one which has a relatively high melting temperature. Both characteristics assist in defeating modification of the part 2 by tampering, such as by inserting a heated probe into the housing before the seal is closed as hereinafter described. By way of example, the main component 1 may be formed of polypropylene, and the part 2 may be formed of acetal.

In the- construction shown, the part 2 comprises a collar 10 and three flexible fingers 11 extending axially from one side of that collar. It will be appreciated that the number of fingers can vary according to requirements.

An opening 12 is formed through the collar 10 and communicates with a space 13 surrounded by the fingers 11.

The opening 12 and the space 13 form part of a passage of the housing which receives the bar 4, or at least receives the head 8 connected to that bar 4.

As best seen in Figures 2 and 3, the fingers 11 are preferably long and therefore highly flexible. That feature maximises resistance to tampering as hereinafter explained.

The part 2 is dimensioned to fit loosely within a cavity 14 which is formed within the housing body 3 and is preferably closed at one end by an end wall 15. It is further preferred, as shown, that a step 16 is formed in the cavity 14 at a location between the wall 15 and a cavity open mouth 17. That step 16 forms a seat upon which the collar 10 rests when the part 2 is inserted into the cavity 14 as shown in Figures 5 and 6. When the part 2 is so positioned, it is free to rotate relatively to the body 3 about the axis 18 as shown in Figure 2.

A cap 19 is used to provide a barrier over the open mouth 17 of the cavity 14 and thereby retain the part 2 against separation from the housing body 3. Such retention of the part 2 is achieved without seriously disturbing the ability of the part 2 to rotate relatively to the body 3 as referred to above. In the arrangement shown, the cap 19 includes a plug 20 which fits neatly within the cavity 14.

The cap 19 may be secured in place by ultrasonic welding or any other suitable means. An entrance hole 21 is formed through the cap 19 for a purpose hereinafter described.

It is preferred that the cap 19 is formed integrally with the main component 1, and in the particular arrangement shown it is connected to the housing body 3 through a flexible strap 22.

The seal is ready to use when the part 2 is within the housing body 3 and the cap 19 is secured in place. Any attempt to tamper with the detent fingers 11 by inserting a tool through the hole 21 will be defeated by the flexibility of the fingers 11 and the ability of the part 2 to rotate. That is, flexibility of the fingers makes it difficult to press a heated tool against them so as to modify the fingers to an extent such that they cannot function properly. Also, modification by removal of material from the fingers 11 by a rigid tool such as a file, is defeated by the fact that the part 2 is not rigidly located within the housing body 3, but is free to move within that body.

When it is desired to close the seal, the head 8 is inserted through the hole 21 and the space 13 between the fingers 11 and is thereby pressed against the inner sides of the fingers 11. Continued movement in that direction is permitted by the fingers 11 flexing radially outwards relatively to one another until the tooth 7 goes beyond the free terminal ends of the fingers 11. At that time the fingers 11 snap inwards because of their resiliency, and thereby locate behind the tooth 7 so as to prevent withdrawal of the bar 4 from the housing body 3.

In the closed position of the seal, the bar 4, the tab 6 and the strap 5 form a closed loop which can be broken only by causing visible damage to the seal.

It will be apparent that the security seal shown can be modified in a number of ways whilst still retaining the benefits of the invention. For example, the bar 4 may be flexible and may have a plurality of teeth provided along its length, and the passage within the housing may continue completely through that housing.

Figures 9 to 11 show an embodiment of the invention which utilises the aforementioned modifications. In those Figures, components corresponding to components of the Figures 1 to 8 embodiment are identified by like reference numerals, except that they are in the number series 100 to 199.

In the construction shown, the strap 105 is connected at one end to the housing body 103 through a tab 106, and has a plurality of teeth 107 formed along its length in spaced relationship. Each tooth 107 is of ratchet form so as to lock against the detent means only when the strap 105 is moved longitudinally in one direction relatively to the detent means. The strap 105 is generally of circular cross-sectional shape and is flexible.

The housing body 103 is very much the same as that of the previously described embodiment, except that the passage through that body is open ended. A hole 123 is formed through the end wall 115 for that purpose, and is dimension to allow passage of the strap teeth 107.

An inner detent part 102, constructed as described in relation to the embodiment of Figures 1 to 8, is loosely located in the housing body 103 and is held against escape by a secured cap 119, having an entrance hole 121.

Operation of the seal is as discussed in relation to the Figures 1 to 8 embodiment, except that the strap 105 can be pulled completely through the housing body 103 to adjust the size of the loop formed by the closed seal.

A security device according to the invention has the important benefit of being resistant to pre-use tampering and that enables users to be confident of the security of the device when in use.

Claims (26)

1. A security device including a hollow housing, an entrance to the interior of said housing, detent means located within said housing and abutment means insertable into said housing through said entrance and being cooperable with said detent means when so inserted so as to be thereby held against withdrawal from said housing through said entrance, said detent means being movable relatively to said housing, and retaining means holding said detent means against removal from said housing.

2. A security device according to claim 1, wherein said abutment means and said housing are connected through connecting means, at least part of which is flexible.

3. A security device according to claim 2, wherein said connecting means includes a flexible strap extending between said housing and a tab, and said abutment means is connected to said strap through said tab.

4. A security device according to any preceding claim, wherein said detent means includes a passage which receives said abutment means, said passage is substantially aligned with said entrance, and said movement of the detent means relatively to the housing includes or comprises movement of said detent means about a longitudinal axis of said passage.

5. A security device according to any preceding claim, wherein said detent means includes a substantially annular collar and a plurality of flexible fingers extending from one side of said collar generally in the axial direction of the collar, and said one side is the side of the collar remote from said entrance.

6. A security device according to claim 4 and claim 5, wherein said passage is substantially coaxial with said collar and is defined at least in part by said fingers.

7. A security device according to claim 6, wherein at least a portion of said passage reduces in transverse cross-sectional size in a direction towards the end thereof remote from said collar.

8. A security device according to claim 7, wherein said passage has its minimum cross-sectional size at or adjacent the terminal ends of said fingers which are remote from said collar.

9. A security device according to any one of claims 5 to 8, wherein said retaining means includes an internal shoulder of said housing which is arranged in opposed relationship to said one side of the collar.

10. A security device according to any one of claims 5 to 9, wherein there are three of said fingers.

11. A security device according to any preceding claim, wherein said detent means is formed separate from said housing, said housing includes a body having an opening at one end and a wall at an opposite end thereof, and said retaining means includes a cap which is secured to said body to at least partially close said opening after said detent means is located in said body.

12. A security device according to claim 11, wherein said entrance is formed through said cap.

13. A security device according to claim 11 or claim 12, wherein a hole is formed through said wall to permit at least part of said abutment means to be passed completely through said housing.

14. A security device according to any preceding claim, wherein said abutment means includes at least one locking tooth which is co-operable with said detent means.

15. A security device according to claim 14, wherein said locking tooth includes a head section having a longitudinal axis and a substantially transverse abutment surface at one end, and said abutment surface is engageable by said detent means to effect said co-operation between the detent means and the abutment means.

16. A security device according to claim 15, wherein said head section reduces in transverse cross-sectional size in a direction away from said abutment surface.

17. A security device according to claim 15 or claim 16, wherein said one end of said head section is connected to an elongate bar through a neck portion of reduced crosssectional size.

18. A security device according to claim 17, wherein the end of said bar remote from said head section is connected to said housing.

19. A security device according to any one of claims 1 to 12, wherein said entrance is provided at one end of said housing and an exit opening is provided at another end of said housing in substantial alignment with said entrance, whereby at least part of said abutment means can be passed completely through said housing.

20. A security device according to claim 19, wherein said abutment means includes an elongate member having a plurality of locking teeth formed thereon, each said tooth has an abutment surface which is engageable with said detent means to effect said co-operation, and said abutment surfaces are spaced apart in the longitudinal direction of said elongate member.

21. A security device according to any preceding claim, wherein said housing is formed of a first material and said detent means is formed of a second material, and said second material is harder than said first material.

22. A security device according to claim 21, wherein said second material has a higher melting temperature than said first material.

23. A security device according to claim 21 or claim 22, wherein both of said materials are plastics materials.

24. A security device according to any preceding claim, wherein said abutment means is formed integrally with said housing.

25. A security device according to any preceding claim, wherein said movement of the detent means relatively to the housing is movement about an axis of rotation of said detent means.

26. A security device substantially as hereinbefore described with reference to Figures 1 to 8, or Figures 9 to 11, of the accompanying drawings.