GB2219554A - Strap-type security seal - Google Patents

Abstract

A security seal of the flexible strap-type has a hollow housing 12 and a metal insert 1 located within that housing and through which a passage extends for receiving a strap 10. An end portion of the strap 10 is securely connected to the insert 1 by being looped around a stirrup 8 on the insert before the insert is located within the housing 12. The insert cannot be moved out of the housing in one direction because of an abutment, shoulders 20, and when located in the housing retainer tangs 22 of the insert are deformed to provide means for preventing movement of the insert out of the housing in an opposite direction. The insert 1 is therefore positively secured within the housing 12 so as to be resistant to tampering. It is a further feature that the connection between the strap 10 and the insert 1 is fully contained within the housing 12 when the assembly is completed. <IMAGE>

Description

"STRAP-TYPE SECURITY SEAL" This invention relates to security seals as used to protect articles and packages, for example, against tampering. One important use for such seals is in relation to cash and document bags, and it will be convenient to hereinafter describe the invention with particular reference to that example use.

One commonly used cash bag seal is the Brooks seal, which is the subject of U.S. patents 3,117,812 and 3,167,340.

That seal comprises three parts, a plastic housing, a metal insert contained by the housing, and a flexible strap (e.g., of polypropylene) which constitutes the tying element of the seal. The seal is supplied with one end of the strap secured to the metal insert, and that securing is effected by physically and permanently distorting the insert while the strap is located therein so that the strap end is trapped in a bent or undulating passage. The metal insert is not secure to the housing until after a second crimping operation as referred to below.

When the Brooks seal is used, the free end of the strap is passed through or around an appropriate part of the bag to be sealed and is then projected through a passage in the housing. A loop is thereby formed by the portion of the strap extending between the ends which are attached to the housing.

The strap is moved through the housing passage to reduce the loop to the desired size, and a special seal crimping tool is then applied to the housing and operated to cause distortion of the metal insert in such a way as to trap that part of the strap which is within the aforementioned passage. That operation also serves to secure the metal insert to the housing.

A disadvantage of the Brooks seal is that the metal insert is not secured to the plastic housing until the final crimping operation, and the resulting connection between the housing and the insert is not sufficiently secure to prevent their subsequent separation. The security of the seal is thereby disturbed such that tampering can take place. Another disadvantage of the Brooks seal is that the point of initial attachment between the strap and the metal insert is exposed in the final assembly. As a result, it is possible to detach and reattach the strap for the purpose of gaining non-detectable access to the article or package with which the seal is associated.

It is an object of the present invention to provide an improved seal of the foregoing kind. In particular, it is an object of the invention to provide such a seal in which the interconnection of the metal insert and the housing is more secure than in prior seals of the same kind and is effected separate from the final crimping operation. It is another object of the invention to provide an improved method of attaching the strap to the metal insert. Still another object of the invention is to provide an improved method of making a security seal. Other objects and advantages of the invention will be apparent from the following detailed description of one particular embodiment of the invention.

According to one aspect of the present invention, there is provided a security seal including, a hollow housing, a metal insert located within said housing, a passage extending through said insert, abutment means on said insert coacting with said housing to prevent removal of the insert from the housing in one direction, retention means on said insert spaced from said abutment means and coacting with said housing to prevent removal of the insert from the housing in a direction opposite to said one direction, a flexible strap, and a connection between said insert and an end portion of said strap and which is located substantially completely within said housing, the arrangement being such that the end of said strap opposite said end portion is insertable into said passage to form said strap into a closed loop.

According to a further aspect of the invention, there is provided a method of producing a security seal including the steps of, connecting an end portion of a flexible strap to a tubular metal insert so that separation of the strap and the insert is resisted, locating said insert within a hollow housing so that said connection is positioned substantially completely within said housing, said insert and said housing being arranged so as to coact in a manner such as to prevent removal of the insert from the housing in one direction, and deforming part of said insert so as to coact with said housing to prevent removal of said insert from the housing in a direct ion opposite to said one direction.

It is a feature of the invention that the metal insert is connected to the housing through positive retention means which is rendered operative prior to crimping the strap into a loop. The seal is further characterised in that the strap is connected to the metal insert through a connection which is substantially fully contained within the housing when the seal is in the assembled condition. In a preferred arrangement, that connection is a looped form of connection.

In one particular form of the seal which is hereinafter described in greater detail, the metal insert is of flat tubular form to provide a strap passage, and means is provided external of that passage to permit initial attachment of one end portion of the strap to the metal insert. That attachment means preferably includes two spaced stirrups and the strap is looped about one of those stirrups to positively hold it against separation from the metal insert.

Retention means is provided to positively secure the metal insert to the housing. In a preferred arrangement, the metal insert is located within a passage which extends through the housing and is shaped so as to interact with the housing to prevent movement completely through the passage in one direction. Tangs of the metal insert are deformable so as to be engageable with internal shoulders of the housing passage and thereby prevent separation of the housing and insert by relative movement of the insert in the direction opposite to the aforementioned one direction.

It is further preferred that the looped connection referred to above is fully contained within the housing when the housing and metal insert are secured together by activation of the retention means.

The nature of the invention will be more fully explained by reference to the accompanying drawings which illustrate one particular form of security seal according to a presently preferred embodiment of the invention.

An embodiment of the invention is described in detail in the following passages of the specificaton which refer to the accompanying drawings. The drawings, however, are merely illustrative of how the invention might be put into effect, so that the specific form and arrangement of the various features as shown is not to be understood as limiting on the invention.

In the drawings: Figure 1 is a plan view of an insert part of a security seal according to one embodiment of the invention, Figure 2 is a side elevational view, partly sectioned, of the insert shown in Figure 1, Figure 3 is a view similar to Figure 1 but showing a strap attached to the insert, Figure 4 is an enlarged cross-sectional view taken along line IV-IV of Figure 3, Figure 5 is an end view of a housing suitable for use with the insert of Figure 1, Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5, Figure 7 is a cross-sectional view taken along line VII-VII of Figure 5, Figure 8 is a view of an assembly of the strap insert and housing shown in the previous views, Figure 9 is an enlarged cross-sectional view taken along line IX-IX of Figure 8, Figure 10 is a partly sectioned perspective view of the assembly shown in Figure 8 but also showing the free end of the strap inserted through the strap passage of the assembly.

Figures 1 and 2 show one form of metal insert 1 which has been found satisfactory for the purposes of the present invention. The insert 1 includes a flat tubular section 2 which defines an open ended strap passage 3. A cutting guard 4 extends beyond one end of that passage 3 in accordance with conventional practice. Crimp activated means is provided to hold the strap within and against separation from the passage 3, and in the arrangement shown that comprises a toothed section 5 which is formed integral with an upper wall 6 of the tubular section 2.

Strap connecting means is also provided on the insert 1 to enable initial connection of an end portion of the strap.

In the construction shown, that includes two stirrups 7 and 8 which are formed integral with the upper wall 6 and stand proud from an external surface of that wall as shown in Figure 2. As best seen in Figure 1, it is further preferred that an opening 9 formed through the upper wall 6 extends beyond both sides of the stirrup 8. An arrangement of the foregoing kind is particularly suited to providing a looped connection for the strap, but it is not the only possible arrangement for that purpose.

The strap may be of a known form, such as a flat section of oriented polypropylene having a sufficiently high tensile breaking strength (e.g., 1200 Newtons). The opposite flat surfaces of the strap may be suitably roughened, such as by forming a diamond pattern knurl on each of those surfaces.

Figures 3 and 4 show the manner of attachment of a strap 10 to the insert 1 previously described. As best seen in Figure 4, the end portion 11 of the strap 10 is passed beneath the stirrup 7 to extend across the upper surface of the upper wall 6. It is then passed beneath the stirrup 8 by way of the opening 9, and then looped back across the top of the stirrup 8. The important point is that the strap 10 is looped about the stirrup 8, and it is a matter of preference whether the strap 10 is initially passed beneath the stirrup 8 as shown, or initially passed over the stirrup 8 to be looped back beneath that stirrup. If desired, the security of the connection between the strap 10 and the insert 1 may be improved by pushing the stirrup 8 downwards towards the upper wall 6 and perhaps to a position at which it locates within the opening 9.

It will be evident that a looped connection as described provides a very secure connection between the strap 10 and the insert 1. Such a connection can be achieved in a manner different to that described. Also, a connection other than a looped connection may be adopted.

Figures 5 to 7 show one particular form of housing which is suitable for use with the insert 1 as described. The housing 12 as shown may be formed from polypropylene, polyethylene, or any other suitable plastics material.

Polypropylene is preferred, however, because of its stress whitening characteristic which facilitates marking of the housing with a code or other mark. Stress whitening can also reveal whether an attempt has been made to tamper with the seal.

The housing 12 as shown includes a flat tubular section 13 having relatively thin upper and lower walls 14 and relatively thick side walls 15, and an open ended passage 16 which is defined between the walls 14 and 15. An enlarged mouth 17 is provided at one end 18 of the housing 12 so as to be adapted to contain that part of the insert 1 having the stirrup 7 formed thereon. A laterally projecting flange 19 is also provided on the upper and lower walls 14 at the same end 18 of the housing 12.

Figures 8 and 9 show the insert 1, with the strap 10 attached, located within the housing 12. The insert 1 is moved into the housing passage 16 through the mouth 17 and is pushed into that passage to a position at which the tubular section 2 of the insert 1 is fully contained within the passage 16. That position is determined by abutment shoulders 20 (Figure 3) of the insert 1 engaging the opposed shoulders 21 (Figure 6) within the housing mouth 17. It is preferred that the insert 1 is a reasonably firm fit within the housing passage 16.

Retention means is provided whereby the insert 1 can be secured against separation from the housing 12 by removal through the mouth 17. In the particular construction shown, that means includes two side tangs 22 (Figures 3 and 4) of the insert 1 and internal shoulders 23 (Figure 7) formed on the side walls 15 of the housing 12. As seen in Figure 7, it is preferred that each shoulder 23 slopes outwardly to form a vee shaped recess 24 within the respective side wall 15. When the insert 1 is properly located within the housing passage 16, a tool is employed to bend each tang 22 outwards and back into the adjacent recess 24 as shown in Figure 8.

It will be apparent from the foregoing that the insert 1 is firmly retained against separation from the housing 12 by the outwardly and backwardly bent tangs 22. Furthermore, the location of those tangs 22 inwardly from the adjacent end 25 of the housing 12 makes it extremely difficult for them to be manipulated to an inoperative condition. That difficulty is increased by the fact that the tangs 22 extend rearwardly into the recesses 24. Other types of retention means may be adopted, but the particular form described has been found to be very satisfactory.

An advantage of the arrangement particularly described is that the looped connection between the strap 10 and the insert 1 is fully contained within the housing 12 and is thereby guarded against tampering. A further advantage arises out of the relatively thin nature of the portions 26 of the housing side walls 15 which are at the housing end 18. Those wall portions 26 will fracture if the seal is subjected to excessive tension and thereby reveal that an attempt has been made to tamper with the seal.

The seal as described is made ready for use in the conventional manner. That is, in use, the free end 27 (Figure 10) of the strap 10 is inserted into the insert passage 3 through the housing end 18 so that the body of the strap 10 is formed into a loop 28 (Figure 10). The strap 10 is pulled through the passage 3 to produce the desired tension in the loop 28. A crimping tool of a known kind is then applied to the body of the housing 12 and is operated to cause the toothed section 5 of the insert 1 to project into the passage 3 and grip the strap 10. Operation of the crimping tool may simultaneously cause embossing of at least one of the housing walls 14, and the relatively thick nature of the walls 15 assists in achieving clearly defined embossing. Those thick walls 15 also assist in ensuring maximum distortion of the insert 1 during crimping and thereby ensures maximum security of the seal.

A seal as described has several advantages over prior seals of the same general kind. The improved security of the seal is of particular importance, and features which are relevant in that regard are the containment of the strap and insert connection within the housing, and the positive retention of the insert against separation from the housing.

Claims (13)

1. A security seal including, a hollow housing, a metal insert located within said housing, a passage extending through said insert, abutment means on said insert coacting with said housing to prevent removal of the insert from the housing in one direction, retention means on said insert spaced from said abutment means and coacting with said housing to prevent removal of the insert from the housing in a direction opposite to said one direction, a flexible strap, and a connection between said insert and an end portion of said strap and which is located substantially completely within said housing, the arrangement being such that the end of said strap opposite said end portion is insertable into said passage to form said strap into a closed loop.

2. A security seal according to claim 1, wherein said retention means includes at least one tang which is bent subsequent to location of the insert within the housing so as to effect said retention means coaction.

3. A security seal according to claim 2, wherein said insert is of flat tubular form, a said tang is provided at each of two opposite sides of the insert, and each said tang is at one end of the insert.

4. A security seal according to claim 2 or 3, wherein said tang is bent into a recess formed in an internal shoulder of said housing.

5. A security seal according to any preceding claim, wherein said abutment means includes at least one shoulder formed on said insert and which is in opposed relation to a surface of said housing.

6. A security seal according to any preceding claim, wherein said connection includes a stirrup formed integral with a wall of said insert, and said strap end portion is looped about said stirrup.

7. A security seal according to claim 6, wherein said strap extends over an external surface of said wall and said strap end portion is located outside of said passage.

8. A security seal according to claim 6 or 7, wherein a further said stirrup is formed integral with said wall, the two said stirrups are spaced apart in the longitudinal direction of said passage, and a portion of said strap adjacent said end portion passes beneath said further stirrup

9. A security seal according to claim 8, wherein the two said stirrups are located within said housing.

10. A security seal according to any preceding claim, wherein said housing is composed of a plastics material, a part of said insert extends out of said housing through an open mouth thereof, and wall portions of said housing which form a boundary of said mouth are relatively thin so as to fracture when stressed.

11. A method of producing a security seal including the steps of, connecting an end portion of a flexible strap to a tubular metal insert so that separation of the strap and the insert is resisted, locating said insert within a hollow housing so that said connection is positioned substantially completely within said housing, said insert and said housing being arranged so as to coact in a manner such as to prevent removal of the insert from the housing in one direction, and deforming part of said insert so as to coact with said housing to prevent removal of said insert from the housing in a direction opposite to said one direction.

12. A security seal substantially as herein particularly described with reference to what is shown in the accompanying drawings.

13. A method of forming a security seal substantially as herein particularly described with reference to what is shown in the accompanying drawings.