GB2205279A - Security seals - Google Patents

Abstract

In a security seal 116 of the kind having a flexible strap 118 integrally formed of a plastics material, such as relatively soft polypropylene, with a housing 120 having a passageway extending therethrough, at least one resiliently deformable stop 110 projecting into the passageway and a plurality of ratchet-like teeth 128 projecting from the strap to permit successive ones of said teeth to be moved through the passageway past said at least one stop 110 in one direction, but not the other, the improvement is that a socket including said at least one stop is formed of a different plastics material, such as relatively hard nylon 6.6, said socket preferably being moulded in two socket portions 102a, 102b which are caused to fit together before said housing 120 is moulded therearound. <IMAGE>

Description

SECURITY SEALS The present invention is concerned with security seals, of the kind that may be secured tightly around the. necks of cash bags, for example, to act as seals which must be broken before the cash bags can be opened.

A security seal of the stated kind usually comprises: a flexible strap integrally formed of a plastics material with a housing having a passageway extending therethrough, one end of the strap being secured with respect to the housing, the other end of the strap being free to be receivable by and movable with respect to the passageway, at least one resiliently deformable stop projecting into the passageway, and a plurality of ratchet-like teeth projecting from the strap to permit successive ones of said teeth to be moved through the passageway past said at least one stop in one direction, but not the other.

An interested reader should refer to the security seals of the stated kind disclosed in our GB 2,106,840A.

An aim of the present invention has been to permit the possibility of improvement of the security seals of the stated kind by the utilisation of plastics materials of different properties.

According to the present invention, a security seal of the stated kind comprises a socket open at opposite ends and embedded within the housing in alignment with the passageway through the housing, said plurality of teeth being integrally formed with the strap and the housing of a plastics material separately from said at least one stop and the socket which are formed of a different plastics material.

It will be appreciated that the socket and said at least one stop can be formed of a relatively hard plastics material, such as nylon 6.6, whereas the housing, the strap and said plurality of teeth can be formed of a relatively soft plastics material, such as polypropylene.

It will be further appreciated that the relatively hard plastics material can provide strength and resistance to tampering, whereas the relatively soft plastics material can be easily defaced or otherwise damaged in an apparent manner if subjected to tampering.

In a first embodiment, of particular application to a passageway of circular transverse cross-section, the socket is formed as two socket portions joined together by a manipulatable portion in the form of a strap of sufficient length to allow rims of the socket portions to fit one within the other. In a second embodiment, of particular application to a passageway of rectangular transverse cross-section, the socket is formed as two socket portions joined together in end-to-end relationship by a frangible portion to allow the socket portions to fit one within the other after the frangible portion has been broken.

Alternatives to said first embodiment of the socket are that: it could be formed in more than one piece rather than being integrally formed; it could be formed with a manipulatable portion in the form of a hinge rather than a strap; it could be formed with flat rims which merely abut rather than rims which fit one within the other; and it could be secured in a sleeve-defining condition ready to be embedded within the housing, for example by adhesive or ultrasonic welding, rather than being merely manipulated to said sleeve-defining condition of readiness.

Said at least one stop could be in the form of, for example, either a plurality of resiliently deflectable fingers or a single resiliently deflectable constriction.

Alternatives to said second embodiment of the socket are that: it could be formed in more than one piece rather than being integrally. formed; it could have the frangible portion extending continuously or dis-continuously around the adjacent inter-connected ends of the socket portions; it could have a flange at an end of an inner socket portion to be brought into abutment with an end of an outer socket portion; and it could be secured in a sleeve-defining condition ready to be embedded within the housing, for example by adhesive or ultrasonic welding, rather than being merely manipulated to said sleeve-defining condition of readiness.

Said at least one stop could be formed on the inner socket portion as, for example, a pair of opposed resiliently deflectable fingers which are either in an aligned or in a staggered relationship to one another.

A practical restraint, of relevance to both the first and the second embodiments of the socket, is that during the manufacturing step of embedding the socket within the housing, the plastics material of the housing should not enter the opposite open ends of the socket, and to resist such an in-flow the socket may be held on one or more retaining pins extending into a mould for the housing.

Two security seals, 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 plan view of a first socket in its as-moulded condition; Figure 2 is a cross-section taken on the line II - II; Figures 3 and 4 are respectively, on a reduced scale, a plan view and a side view taken in the direction of the arrow IV, of a first security seal incörporating the first socket; Figure 5 is a fragmentary schematic partial cross-section showing the first security seal in use; Figures 6 to 9 are respectively cross-sections taken on the lines VI - VI and VII - VII, a left hand view and a right hand view of a second socket in its as-moulded condition;; Figures 10 and 11 are respectively a fragmentary cross-section of just an inner socket portion, and a longitudinal cross-section of the inner socket portion when fitting within an outer socket portion, of the second socket; Figures 12 and 13 are respectively, on a reduced scale, a side view and a plan view taken in the direction of the arrow XIII of a second security seal incorporating the second socket; and Figure 14 is a fragmentary schematic partial cross-section showing the second security seal in use.

Referring initially to Figures 1 and 2, a first socket 10 is illustrated in its as-moulded condition.

The socket 10 is integrally formed of nylon 6.6 as two cup-like socket portions 12a, 12b joined together by a manipulatable portion in the form of a strap 14. The socket portion 12a includes a peripheral wall 16 having an annular rim 18 at one end and an annular wall 20 at its other end. The wall 20 defines an open cylindrical entrance 22 leading to three resiliently deflectable fingers 24 which converge with increasing distance from the entrance 22. The socket portion 12b includes a peripheral wall 26 having an annular rim 28 at one end, an annular shoulder 30 formed near its junction with the strap 14, and an open exit 32 at its other end.

By manipulating the strap 14, the socket portions 12a and 12b can be brought into a condition in which the socket 10 defines a sleeve which is closed, apart from at the opposite open ends 22 ar.d 32. The condition is shown in schematic cross-section in Figure 5. To assist in the manipulation, the inner edge of the rim 18 and/or the outer edge of the rim 28 can be chamfered, the rim 28 being a tight press fit within the rim 18 to ensure that the sleeve-defining condition of the socket 10 is maintained. It is particularly clear from Figure 5 that, when the rim 28 fits fully within the rim 18, the shoulder 30 rests upon the rim 18.

The socket 10 in it sleeve-defining condition, is held centrally within a two-part mould for the remainder of the security seal by being placed between a pair of retaining pins. One of the retaining pins includes a cylindrical portion complementary to the entrance 22 defined by the wall 20 of the socket portion 12a, and further includes a bulbous portion which is just sufficiently large to make releasable steadying engagement with the free ends of the resiliently deflectable fingers 24. The other of the retaining pins includes a cylindrical portion complementary to the eit 32 defined by the wall 26 of the socket portion 12b.

After moulding of the remainder of the security seal around the socket 10, the retaining pins are withdrawn as a consequence of being secured to respective parts of the two-part mould.

A typical first security seal 34 in accordance with the present invention is shown on a reduced scale in Figures 3 and 4. The security seal 34 includes a flexible strap 36, a housing 38 and a tab 40 which are formed of polypropylene integrally with one another in the two-part mould. One end of the strap 36 extends orthogonally to the junction of the housing 38 and the tab 40. The other end of the strap 36 is free and is to be inserted through then pulled through a passageway 42 extending through the housing 38. The ends of the straps 36 are separated by an intermediate portion presenting a series of ratchet-like teeth 44 each including a frusto-conical peripheral wall 46 and an abrupt shoulder 48.

It is clear from Figure 5 that, as a result of the moulding operation, the socket 10 becomes embedded in the housing 38. Indeed, the housing 38 shrinks tightly onto the socket 10 apart from at openings 50 and 52. The opening 50 is defined by a part of the cylindrical portion of that retaining pin extending through the entrance 22, and the opening 52 is similarly defined by a part of the cylindrical portion of that retaining pin extending through the exit 32. It is also clear from Figure 5 that, when the strap 36 is pulled in the direction of the arrow through the passageway 42, successive ones of the frusto-conical peripheral walls 46 of the teeth 44 cause the fingers 24 to flex apart, before the fingers 24 snap back to abut successive ones of the abrupt shoulders 48.The strap 36 cannot then be pulled through the passageway 42 in the direction opposite to that indicated by the arrow in Figure 5.

A second socket 100 is illustrated n Figures 6 to 9 in its as-moulded condition. The socket 100 is integrally formed of nylon 6.6 as an outer socket portion 102a and an inner socket portion 102b joined together in end-to-end relationship by a frangible portion 104. The outer socket portion 102a includes a hollow open-ended rectangular peripheral wall 106. The inner socket portion 102b also includes a hollow open-ended rectangular periphcral wall 108, whose dimensions are slightly smaller than those of the wall 106 so that the wall 108 is slidable tightly within the wall 106. Two opposed faces of the wall 108 are formed with respective resiliently deflectable fingers 110, as shown in Figure 10, whose free ends are in staggered relationship to one another considered longitudinally of the socket 100.For moulding purposes, each of said two opposed faces of the wall 108 is formed with an opening 112. The other two opposed faces of the wall 108 can be either integral with or separated from the fingers 110 provided that the fingers 110 are resiliently deflectable.

Pushing the inner socket portion 102b towards the outer socket portion 102a, in the direction of the arrow as shown in Figure 11, breaks the frangible portion 104 to allow the wall 108 to slide within the wall 106.

This continues until a peripheral flange 114 at one end of the inner socket portion 102b abuts one end of the outer socket portion 102a. The socket 100 is then ready to be held centrally within a two-part mould for the remainder of the security seal, in a manner similar to that previously described.

A typical second security seal 116 in accordance with the present invention is shown on a reduced scale in Figures 12 and 13. The security seal 116 includes a flexible strap 118, a housing 120 and a tab 122 which are integrally formed with one another of polypropylene. The major differences from the previously described security seal 34 are the presence in the security seal 116 of a line of weakness 124 for use in removal from a cash bag which has been protected, a series of sharp spikes 126 for gripping engagement during use with the cash bag, and two series of staggered ratchet-like teeth 128 on opposite sides of the strap 118. Each of the teeth 128 has a part-spherical face 130 to act as a cam and a flat face 132 te act as a shoulder.

When the strap 118 is pulled in the direction of the arrow in Figure 14, successive ones of the part-spherical faces 130 cause the fingers 110 in the socket 100 to be deflected before they return to abut successive ones of the flat faces 132 of the teeth 128. The strap 118 cannot then be pulled in the direction opposite to that indicated by the arrow in Figure 14 through the passageway extending through the socket 100 and the housing 120.

To prevent the straps 36 or 118 being inserted through the housings 38 or 120 from the wrong ends, a reversely facing ratchet-like tooth 44 or 128 may be provided as the nearest tooth to the free ends of the straps 36 or 118, as indicated in dotted outline at 150 in Figure 12.

Claims (8)

1. A security seal comprising a flexible strap formed of a plastics material with a housing having a passageway extending therethrough, one end of the strap being secured with respect to the housing, the other end of the strap being free to be receivable by and movable with respect. to the passageway, at least one resiliently deformable stop projecting into the passageway, and a plurality of ratchet-like teeth proJecting from the strap to permit successive ones of said teeth to be moved through the passageway past said at least one stop in one direction, but not the other, characterised in that a socket open at opposite ends is embedded within the housing in alignment with the passageway through the housing, said plurality of teeth being integrally formed with the strap and the housing of a plastics material separately from said at least one stop and the socket which are formed of a different plastics material.

2. A security seal according to claim 1, characterised in that the plastics material of the socket and said at least one stop is harder than the plastics material of the housing, the strap and said plurality of teeth.

3. A security seal according to claim 1 or claim 2, characterised in that the socket is formed as two socket portions joined together by a manipulatable portion in the form of a strap of sufficient length to allow rims of the socket portions to fit one within the other.

4. A security seal according to claim 1 or claim 2, characterised in that the socket is formed as two socket portions initially joined together in end-to-end relationship by a frangible portion to allow the socket portions to fit one within the other after the frangible portion has been broken.

5. A security seal according to claim 4, characterised in that said at least one stop is formed on an inner of the two socket portions as a pair of opposed resiliently deflectable fingers in a staggered relationship to one another along the passageway.

6. A security seal according to claim 4 or claim 5, characterised in that an outer of the two socket portions has a hollow open-ended rectangular peripheral wall.

7. A security seal according to any preceding claim, characterised in that a reversely-facing ratchet-like tooth is provided as the nearest tooth to the free end of the flexible strap to prevent the flexible strap being inserted through the housing from the wrong end.

8. A security seal substantially as hereinbefore described with reference to Figures 1 to 5, or Figures 6 to 14, of the accompanying drawings.