GB2134046A - Security seal - Google Patents

Abstract

A security seal of integrally moulded plastics material has an elongate strap with a socket 14 at one end, a stud 16 at a medial portion, and a free end apertured at 20 to be received on the stud before the stud and socket are engaged. The free end may have two or more spaced apertures 20 receivable on the stud and a slot can be provided in the shackle between the stud and socket to receive the free end of the shackle therethrough so that the shackle can be formed into loops of different size. The stud may have weakened portion at the base in a position such that if the weakened portion is cut or broken, the stud is too short to engage in the socket after it has been re-attached by fusing. <IMAGE>

Description

SPECIFICATION Security seal This invention relates to a security seal.

Security seals can be used to seal hasps on enclosures such as vehicle doors, mail bags, the function of the seal being to indicate pilferage.

Known seals for this purpose are often formed of a single piece of moulded plastics material in the form of a strap with a socket formed on one end and a shackle of small diameter extending from the other end, the shackle being arranged for locking non-removable engagement when pulled through the socket. A seal of this type, disclosed in U.S. Patent 4001 919, has been found to be highly satisfactory in many applications, the locking portions are difficult to mould accurately, and tolerance variations sometimes cause the seal to be less secure than desired. It would be desirable to have larger locking means, such as male and female snap fastener portions, but in many of the applications in which such a seal is used, the aperture in the staple through which the seal is assembled is too small to allow a snap fastener portion to pass through.

The invention accordingly provides a security seal comprising a shackle with spaced fastener portions disposed thereon for locking engagement when the shackle is bent on itself to superimpose the fastener portions, the shackle having a portion extending from the fastener portions and provided with at least one aperture for reception on one of the fastener portions to be retained thereon when the fastener portions are lockingly engaged.

Some applications in which the seal is to be used require a long shackle loop, and any one user of the seal might have applications in which a short shackle is adequate, and others in which a longer shackle is necessary. In either kind of application, it is usually necessary that an identifying number be placed on the shackle, and that the number can be readily visible.

The seal of the invention can thus have a plurality of the apertures and'a slot in the shackle for receiving the ends of the apertured shackle portion beyond the aperture when the aperture is assembled onto the one fastener portion.

Preferably the apertured shackle portion has at least two spaced apertures with a medial portion therebetween for receiving identifying marks, a first of the apertures being disposed near the free end of the apertured shackle portion whereby when the seal is assembled with the first aperture received on the one fastener portion a large loop is formed by the apertured shackle portion with the identifying marks on the medial portion being visible on the exterior of the loop, the second of the apertures being disposed near the one fastener portion so that when the seal is assembled with the second aperture disposed on the one fastener portion a small loop is formed by the apertured shackle portion and the free end of the apertured shackle portion extends through the slot with the identifying marks being visible on the free end portion of the shackle extending from the slot.

Such seals are usually provided with a weakened portion in the shackle, which is intended to break when attempts are made by an authorized person to open the seal. However, it has been found that in some instances a seal which has been broken at the weakened portion can be re-assembled, without leaving readily noticeable evidence of tampering, by fusing the broken ends together by heating with a match, a cigarette lighter or the like.

The invention therefore provides a security seal comprising a stud and a socket disposed on a shackle in spaced relation and arranged for locking engagement on insertion of the stud into the socket, the stud comprising a shank extending from the shackle an enlarged head on the shank forming a locking shoulder, and a weakened portion in the shank comprising a web having a cross-sectional area substantially less than that of the remainder of the shank, the weakened portion extends axially a distance such that if the stud is broken at the weakened portion and the broken ends fused together so that the web is destroyed, the length of the stud is so reduced that on insertion of the stud into the socket the locking engagement does not occur.

Embodiments of the invention are described below by way of example with reference to the accompanying drawings, in which: Figure 1 is a plan view of a first seal embodying the invention; Figure 2 is a side view, partly in section, of the seal of Figure 1; Figure 3 is a perspective view of the seal assembled around the staple of a mail bag or the like; Figure 4 is a side view, partly in section, of the seal, showing a stud and a socket thereof assembled together; Figure 5 is a view of the seal of Figure 4 after the stud has been ruptured and the seal opened; Figure 6 is a view taken on line 6-6 of Figure 1; Figure 7 is a view taken on line 7-7 of Figure 6; Figure 8 is a view of the seal after the ruptured stud has been re-fused onto the strap in an attempt to re-attach the stud into the socket; Figure 9 is a plan view of a second seal embodying the invention;; Figure 10 is a side view of the seal of Figure 9 in which a first aperture in a shackle of the seal has been assembled over a stud and a co-operating socket is in position for final assembly; Figure 11 is a perspective view of the seal as shqwn in Figure 10 after final assembly; Figure 12 is a view of the seal of Figure 9 in which a second aperture of the shackle has been assembled onto the stud and the socket is in position for final assembly; and Figure 1 3 is a perspective view of the seal as shown in Figure 12 after final assembly.

Figures 1 to 9 show a seal 10, conveniently integrally formed of moulded plastics material, comprising a shackle in the form of an elongate flat strip 12 having a first snap fastener portion in the form of a socket 14 at one end, a second such portion in the form of a stud 16 projecting from a medial portion of the strap, and a strap free end 18 having an aperture 20. The socket 14 has internal resilient fingers 22 and the stud 1 6 has an enlarged head forming an abrupt locking shoulder 24 so dimensioned that the stud can snap into the socket with the fingers 22 seating behind the stud shoulder 24 to prevent removal of the stud without destruction of the seal.

The seal 10 is intended for assembly through a staple 26 of a mailbag strap 28 or the like, with the free end portion 1 8 bent back on itself so that the aperture 20 may be placed over the stud 1 0.

The portion of strap between the socket 1 4 and the stud 1 6 may then be bent to allow the socket to snap over the stud, as shown in Figure 3. The socket 14 and stud 1 6, because of their size, allow a more secure locking engagement than seals previously used for this purpose, but the free end 18, since it does not carry a fastener portion, is capable of being inserted through a staple in a staple-and-hasp assembly too small to allow a fastener portion to pass through.

To increase the security of the seal by allowing tampering to be detected, the stud 1 6 is provided with a weakened portion with a configuration which will resist the compressive forces applied to the stud during assembly yet will rupture when tensile forces are applied thereto, such as occur in attempts to pry the stud out of the socket 14.

As illustrated, the weakened portion is provided by a pair of slots 30 formed in opposite sides of the shank of the stud 1 6 at the junction with the strap, to leave between them a connecting web portion 32 of the shank which is appreciably smaller in cross-sectional area than the remainder of the shank. If desired the web portion 32 may be formed by a single groove or cavity extending entirely around the periphery of the base of the shank.

When the socket 14 is snapped onto the stud 1 6, the resulting compressive forces may tend to cause the narrow shank portion to collapse, but because the slots 30 are not wide in an axial direction and are at the root of the stud shank, the distance that the stud can move downwardly is limited, which tends to prevent sideways collapsing of the shank. However, when a tensile force is applied to the shank, as when an unauthorized person is attempting to open the seal, the narrow shank portion 32 readily ruptures.

As mentioned above, one method of attempting to defeat seals of this type is to break them and then fuse the broken ends together by the use of heat. In the case of seals in which the weakened portion is in the shackle, the ends of a shackle broken at the weakened portion can be heated simultaneously and forced together. The fact that a small length of shackle is lost in this process is usually of no consequence.

In the present seal, after the stud 1 6 has broken from the strap 12 at the weakened portion at the base, the stud may be pushed out of the socket 14 and re-attached to the shackle by fusion. Although this attachment is more difficult then attaching broken shackle ends by fusing, it can be done with sufficient time by a person experienced in such matters. However, the act of fusing necessary shortens the overall length of the stud 1 6 by a small amount, which amount is at least equal to the thickness of the slots 30, since the connecting web 32 will be destroyed in the 'fusion process.

In the manufacture of the seal, there must be a manufacturing toierance in the dimensions of the stud 1 6 and the fingers 22 to ensure that the fingers will snap behind the shoulder 24 when the stud is fully inserted into the socket 14. In a typical seal of the type described herein, the length of the stud 1 6 is such that the distance from the outer face of the strap 12 to the underside of the shoulder 24 (when the stud is assembled as shown in Figure 4) is about 0.025 cms (.010 inches) greater than the distance from the face of the socket 14, on the stud-entering side, to the ends of the fingers. The axial length of the slots 30 is about 0.076 cms (.030 inches). Therefore, when the stud is broken at the weakened portion and re sealed onto the strap, the stud length is decreased by about 0.076 cms (.030 inches).When the socket 14 is thereafter placed over the stud 1 6 to re-assemble the seal, as shown in Figure 8 the stud is now too short to allow the shoulder 24 to pass beyond the ends of the fingers 22, and the stud cannot be locked into the socket.

Although the friction of the fingers 22 on the head of the stud 1 6 may tend to temporarily hold the stud and socket together, the spring action of the bent shackle portion between the stud and socket will force the socket off the stud.

Although in the illustrated embodiment the socket 14 is open at the end opposite to that at which the stud 1 6 enters, if desired this open end may be closed in any convenient manner, such as by heat sealing a plug into the opening, to provide a more secure seal.

Figures 10 to 14 illustrate a second seal, parts of which equivalent to parts of the seal of Figures 1 to 9 are indicated by the same reference numerals. The second seal 10 thus comprises a shackle in the form of an elongate flat strap 12 having a snap fastener socket 14 at one end and a stud 1 6 projecting from the strap at a position spaced from the socket. A portion 1 8 of the strap extends beyond the stud 1 6 and is narrower than the portion carrying the stud and socket. This strap portion 1 8 is provided with at least two apertures which are spaced apart a predetermined distance for a purpose to be described. Thus, a first aperture 20 is positioned relatively close to the stud 16, and a second aperture 22 is positioned near the free end of the shackle. Identifying numbers or letters may be provided on the strap portion 18 between the apertures 20 and 22. A slot 24 is provided in the strap 12 between the stud 1 6 and the socket 14, the slot being wide enough to receive the narrow portion 18 of the strap when the seal is assembled using the first aperture, as will be described below.

The provision of the elongate shackle portion 1 8 and the two separate and widely spaced apertures 20 and 22 allows the seal 10 to be used with closure fastener of different diamension, and no matter which aperture is used, allows the identifying marks to be visible.

As illustrated in Figures 10 and 11, when the seal is assembled using aperture 22, by placing the portion of the seal having aperture 22 over the stud 1 6 and then folding the portion of the strap 12 between the stud and socket over so that the socket can snap into engagement with the stud, a relatively large loop 26 is formed, allowing the seal to be used with a closure fastener in which the portions of the closure fastener to be sealed are relatively far apart.

As appears from Figure 11, the identifying numbers are clearly visible when the seal is so assembled.

Figures 12 and 13 illustrate assembly of the seal when the seal is to be used with closure fastener having portions cioser together. The free end of the portion 1 8 of the shackle is folded over on itself and inserted through the slot 24 until the aperture 20 can be placed over the stud, forming a small loop 28, and the socket then snapped onto the stud in the manner previously described. The free end of the shackle thereafter projects from the loop 30 formed by the portion of the shackle between the stud and the socket, with the identifying numbers readily visible.

It is, of course, possible to provide apertures in the shackle portion 1 8 at other positions, or at additional positions, for example adjacent the apertures 20 and 22 as shown, but it has bean found that provision of apertures at the positions of apertures 20 and 22 will accommodate most closure fasteners and allows exposure of the identifying numbers.

The transverse slot 24, in addition to receiving the end of the shackle, also provides other functions. It provides a weakened portion which facilitates bending of the strap to effect engagement of the stud 1 6 and socket 14 or other fastener portions, so that on such bending, a major portion thereof occurs at the position of the slot.

The slot is therefore so positioned between the fastener portions that on such bending, the fastener portions become accurately aligned to facilitate engagement.

In the illustrated embodiments of the invention, the socket 1 4 comprises resilient fingers 22 dimensioned to lock beyond the shoulder of the stud 1 6, but other forms of locking stud and socket combinations may be used. Although not shown, the stud 16 of Figures 9 to 13 can if desired incorporate the weakened portion 32. The illustrated embodiments can be modified in a variety of ways without departing from the scope of the invention as defined in the following claims.

Claims (14)

1. A security seal comprising a shackle with spaced fastener portions disposed thereon for locking engagement when the shackle is bent on itself to superimpose the fastener portions, the shackle having a portion extending from the fastener portions and provided with at least one aperture for reception one of the fastener portions to be retained thereon when the fastener portions are lockingly engaged.

2. A security seal as claimed in claim 1 in which the fastener portions are integrally formed snap fastener portions.

3. A security seal formed of a single piece of moulded plastics material, the seal comprising an elongate shackle, a first integral snap fastener portion formed at one end of the shackle, and a second integral snap fastener portion formed at a medial portion of the shackle spaced from both ends thereof, the fastener portions being shaped and dimensioned for locking non-removable engagement, the spacing between the first and second fastener portions being sufficient to allow the portion of the shackle therebetween to be bent back on itself to enable the fastener portions to be engaged, the portion of the shackle extending from the second fastener portion away from the first fastener portion having an aperture at a distance from the second fastener portion such that the portion may be passed through an opening of a closure member to be sealed and then folded back on itself with one of the fastener portions received in the aperture, the step portion being retained in assembly on the one snap fastener portion by engagement therewith of the other fastener portion.

4. A security seal as claimed in claim 1,2 or 3 having a slot in the shackle for receiving the end of the apertured shackle portion beyond the aperture when the aperture is assembled onto the one fastener portion.

5. A security seal as claimed in claim 4 having two spaced apertures in the apertured shackle portion and identifying indicia between the apertures.

6. A security seal as claimed in claim 4 in which the apertured shackle portion has at least two spaced apertures with a medial portion therebetween for receiving identifying marks, a first of the apertures being disposed near the free end of the apertured shackle portion whereby when the seal is assembled with the first aperture received on the one fastener portion a large loop is formed by the apertured shackle portion with the identifying marks on the medial portion being visible on the exterior of the loop, the second of the apertures being disposed near the one fastener portion so that when the seal is assembled with the second apertures disposed on the one fastener portion a small loop is formed by the apertured shackle portion and the free end of the apertured shackle portion extends through the slot with the identifying marks being visible on the free end portion of the shackle extending from the slot.

7. A security seal as claimed in claim 4, 5 or 6 in which the slot weakens the shackle so that, on bending, the shackle bends principally at the position of the slot, the slot being so positioned that on such bending the fastener portions move into alignment for locking engagement.

8. A security seal as claimed in claim 4, 5, 6 or 7 in which the apertured shackle portion is narrower than the shackle between the fastener portions and having the slot.

9. A security seal as claimed in any preceding claim in which the fastener portions comprise a socket having a central aperture with internal resilient fingers, and a stud having a shank and an enlarged head with a shoulder between the head and the shank, the stud and socket being dimensioned to allow the stud to be assembled into the socket in locking non-removable engagement with the fingers seating behind the shoulder.

10. A security seal as claimed in claim 9 in which the shank of the stud has a weakened portion formed therein, the weakened portion having a cross-sectional area substantially less than that of the remainder of the shank.

11. A security seal comprising a stud and a socket disposed on a shackle in spaced relation and arranged for locking engagement on insertion of the stud into the socket, the stud comprising a shank extending from the shackle, and enlarged head on the shank forming a locking shoulder, and a weakened portion in the shank comprising a web having a cross-sectional area substantially less than that of the remainder of the shank, the weakened portion extends axially a distance such that if the stud is broken at the weakened portion and the broken ends fused together so that the web is destroyed, the length of the stud is so reduced that on insertion of the stud into the socket the locking engagement does not occur.

12. A security seal as claimed in claim 11, in which the socket comprises a stud-receiving aperture opening to a face thereof with resilient fingers in the aperture inclined inwardly and away from the face and having ends positioned for snapping into locking engagement behind the locking shoulder of the stud.

13. A security seal as claimed in claim 10, 11 or 12 in which the weakened portion is disposed in the shank at the junction thereof with the strap.

14. A security seal as claimed in claim 10, 11, 12 or 13 in which the weakened portion has an axial length greater than the space between the ends of the fingers and the shoulder when the stud is fully assembled into the socket.

1 5. A security seal as claimed in any preceding claim in which one of the fastener portions extends in one direction from one side of the shackle and the other fastener portion extends in the opposite direction from the other side of the shackle.

1 6. A security seal substantially as herein described with reference to Figures 1 to 8 or Figures 9 to 13 of the accompanying drawings.