WO2005038756A2

WO2005038756A2 - Sealing device

Info

Publication number: WO2005038756A2
Application number: PCT/GB2004/050018
Authority: WO
Inventors: David Sheehan; Michael D. Anderson
Original assignee: Versapak International Limited
Priority date: 2003-10-17
Filing date: 2004-10-14
Publication date: 2005-04-28
Also published as: GB2407065A; WO2005038756A3; GB0324342D0; GB2407065B

Abstract

A sealing device comprising a look portion and a disposable seal, wherein the seal rotates as it is inserted into the lock portion. The seal is retained in the lock portion by snap fit engagement. Rotation of the seal during insertion improves the resistance of the sealing device to tampering. The lock portion preferably comprises a tapered bore into which the seal is inserted and a spiral channel to rotate to the seal as it is inserted. The lock portion also preferably comprises a tray for locating a tag attached to a zipper, thereby enabling the sealing device to seal a zipped bag, such as a mailing pouch. The seal preferably has four resiliently deformable legs with outwardly protruding feet and a disc shaped head attached to the legs by a frangible neck.

Description

SEALING DEVICE

The present invention relates to an improved sealing device. The sealing device is particularly adapted for use in sealing reusable mailing pouches, although it may be used in other applications.

GB 2 357 738 describes a known sealing device of the type suitable for use in sealing a reusable mailing pouch, which is closed by means of a zip fastener. The sealing device comprises a seal and a lock portion. The seal is an expendable item comprising a head and legs joined by a frangible neck. The legs have outwardly protruding feet at their distal ends. The lock portion has a locking arrangement comprising a hole with a maximum width less than the distance between the remote ends of the feet and a depth substantially equal to the length of the legs. The legs are resiliently deformable to allow the feet to move together so that the legs can be inserted into the hole. On full insertion into the hole, the legs spring apart and the feet engage behind shoulders at the bottom of the hole, thereby locking the seal in place.

In use, the lock portion is attached to the mailing pouch adjacent to the zip fastener. When the zip fastener is closed, a tag attached to the slider of the zip fastener is positioned to overlie the lock portion. The seal is inserted into the lock by pushing the legs of the seal through an aperture in the tag and into the hole in the lock portion. Once fully inserted, the legs spring apart and the feet lock behind the shoulders at the bottom of the hole, preventing removal of the seal, whilst retaining the tag and thereby locking the zip fastener in the closed position.

In order to gain access to the mailing pouch, a recipient must break the seal at its neck, thus separating the head from the legs, thereby releasing the slider and allowing the zip fastener to be opened. The bag and lock portion can then be reused with a new seal. One of the primary functions of a sealing device is to prevent access to an object without breaking the seal, so that any access to the object is evident from the broken seal. Such seals are therefore frequently referred to as "tamper-evident" security seals. In the case of a sealing device for a reusable mailing pouch, the sealing device prevents access to the contents of the mailing pouch whilst in transit. If access is gained to a sealed mailing pouch, the seal must be broken and removed from the pouch, and this would be evident to the recipient, who would notice the absence of a seal, that the seal is broken or that a replacement seal has been used. Thus, it should only be possible to remove the seal from a mailing pouch by breaking the seal.

Conventional sealing devices, such as that described in GB 2 357 738, are designed to allow the seal to be pushed straight into the lock portion and to be held there by the engagement of a pair of snap-fit feet with corresponding shoulders of the lock portion. However, insertion of the seal requires the user to carefully position the seal relative to the hole in the lock portion and to push the seal into place in a uniform direction.

The present invention seeks to provide an improved form of tamper-evident sealing device that is suitable for sealing re-useable mailing pouches and the like.

In accordance with the present invention, there is provided a sealing device comprising: a lock portion; and a seal adapted to be inserted into the lock portion to a position of snap-fit engagement therewith, wherein the lock portion includes a guide which engages with and rotates the seal as it is inserted into the lock portion.

Preferably, the lock portion has a bore there-through and a step change in the diameter of the bore forms a shoulder; the seal comprises: a head; a leg portion; and outwardly protruding feet proximate the distal end of the legs, the distance between the remote ends of the feet being greater than the minimum diameter of the bore; the snap-fit engagement results when the feet, which move to allow insertion of the legs into the bore, latch behind the shoulder; and the guide is in the form of spiral channels which engage the feet and rotate the seal as the legs enter the bore. Preferably, the diameter of the bore is tapered from the mouth of the bore, preferably such that the external diameter of the guide tapers from approximately the usual distance between the remote ends of the feet at the mouth to approximately the minimum distance between the remote ends of the feet immediately before the shoulder. Preferably, the shoulder is chamfered so that the inner circumference is further from the mouth of the bore than the outer circumference. Preferably, the step-change in the diameter of the bore results from the bore passing right through the lock portion, so that the bottom of the lock portion forms the shoulder.

Preferably, the lock portion further comprises fixing means comprising holes for receiving extensions from a plate, wherein the plate is placed on one side of the material to which the lock portion is to be fixed with the extensions protruding through the material and into the holes in the lock portion.

The present invention further comprises a seal comprising: a head; a leg portion extending from the head; and one or more outwardly protruding feet proximate the distal end of the leg portion, wherein the remote end of each foot of the seal is nearer the head of the seal than the connection between the foot and the leg portion.

Preferably, the leg portion of the seal comprises a plurality of resiliently deformable legs; and movement of the feet is mainly effected by the deformation of the legs.

Preferably, the leg portion comprises two legs. More preferably, the leg portion comprises four legs. Preferably, the legs are arcuate in cross section and the leg portion resembles a slotted tube with the slots spaced around its circumference.

Further preferred and optional features will be apparent from the following description and accompanying claims.

Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of the components of a sealing device according to a preferred embodiment of the present invention with a zipper tag and a fixing plate;

Figure 2 is a longitudinal cross section of the sealing device and zipper tag of Figure 1 before sealing;

Figure 3 is a longitudinal cross section of the sealing device and zipper tag of Figure 1 after sealing; and

Figure 4a is a side view, and Figure 4b is an end view from the underside of a seal for use in a sealing device according to the present invention.

Figure 1 illustrates a sealing device according to a preferred embodiment of the present invention. The sealing device comprises a seal 1 and a lock portion 2 adapted for snap-fit locking engagement with each other. Thus, when the seal 1 is engaged in the lock portion 2, the seal 1 cannot be separated from the lock portion 2 without it being clearly evident, usually as a result of the seal 1 being broken.

As shown in Figure 1, and in more detail in Figures 4a and 4b, the seal 1 comprises a disk shaped head 11, and four resiliently deformable legs 13 extending from the centre of the underside of the head 11 in a direction substantially orthogonal to the plane of the head 11. The legs 13 are joined together at the end adjacent the head 11 , and to the head 11 by a short frangible neck 12. The legs 13 are generally arcuate in cross section and extend substantially parallel to one another, thus together resembling a slotted tube, the four slots being located between the legs 13. The width of the slots is sufficient to allow the feet to move together when inserted into the lock portion 2. At the distal end thereof, each leg 13 has a foot 14, which extends radially outwards. Hereinafter, the distance between the remote ends 15 of opposed feet 14 when the seal is manufactured is referred to as the "usual distance between the remote ends 15 of the feet 14". However, since the legs 14 are resiliently deformable, an appropriate force may reduce the distance between opposed legs at any given time until there is a "minimum distance between the remote ends 15 of the feet 14" when the legs 13 are touching. Although each foot 14 has a substantially constant width, the depth/thickness of each foot, that is the dimension parallel to the axis of the leg 13, reduces as the foot 14 extends radially from the leg 13 so that each foot 14 is substantially wedge shaped. The top of each foot extends from the leg at an angle upwards, towards the head, so that the remote end 15 of each foot 14 of the seal 1 is nearer the head 11 of the seal 1 than the joint between the foot 14 and its leg 13 when measured perpendicular to the underside of the head. This particular embodiment is shown in cross section in Figures 2 and 3.

The lock portion 2 of the preferred embodiment of the sealing device is also shown in Figure 1. The lock portion 2 comprises a generally rectangular body with a depression across it forming a tray 25. The tray 25 is shaped to hold a tag 3 adapted to attach to the slider of a zip fastener. At one end, the base of the tray 25 is cut away to form a large recess 27 and at the other end the base of the tray is cut away to form a small recess 28. The tray 25 has a bore 21 passing through and pe endicular to its base, and into a tubular projection 29 extending from the underside of the tray 25, so that the bore 21 is longer than the general thickness of the base of the tray 25.

Bore 21 contains a guide 22 which, in the preferred embodiment, comprises four channels which are pitched to spiral 90° (providing a quarter turn) around the circumference of the bore 21 along its length. The channels are proportioned to receive the feet 14 of the seal 1, and the length of the bore 21 is determined according to the length of the legs 13 of the seal 1. The mouth of the bore 21 and the top of the guide 22 are chamfered to facilitate insertion of the seal 1. The diameter of the bore 21 tapers inwardly with distance from the mouth 23 of the bore 21. The external diameter of the guide 22 in the bore 21 tapers from a diameter approximately equal to the usual distance between the remote edges 15 of the feet 14 of the seal 1 at the mouth 23 of the bore 21 to a diameter approximately equal to the minimum distance between the remote ends 15 of the feet 14 of the seal 1 at the other end of the bore 21. Thus, when the legs 13 of the seal 1 are fully deformed towards each other, the feet 14 will just fit through the bore 21. In one embodiment, the minimum distance between the remote ends 15 of the feet 14 of the seal 1 is slightly larger than the minimum diameter of the bore 21 and the feet 14 themselves deform slightly towards the legs 13 in order to allow the seal 1 to be inserted into the bore 21. The remote end of the tubular projection 29 forms an annular shoulder 24 which slopes radially so that it is closer to the back of the tray 25 as the distance from the axis of the bore 21 increases. This shape complements the shape of the feet 14 of the seal 1 as shown in Figures 2 and 3.

The lock portion 2 may be attached to a mailing pouch or other zipped container. In the preferred embodiment, this is facilitated by the provision of an aperture 26 at each corner of the body of the lock portion 2. A fixing plate 4 is used to attach the lock portion 2 to the mailing pouch. Fixing plate 4 comprises a back plate 41 of a similar shape and size as the body of the lock portion with perpendicular projections 42 from its corners that are adapted for engagement with the holes in the lock portion 2. In a preferred embodiment, the back plate 41 has a bore 43 to accommodate the tubular projection 29 from the lock portion 2.

When attached to the mailing pouch, the projections 42 of the fixing plate 4 extend through the fabric of the mailing pouch and into the apertures 26 in the lock portion 2. The projections 42 of the fixing plate 4 are heat sealed or glued to the lock portion 2, thereby fixing the lock portion 2 to the mailing pouch. The tubular projection 29 from the underside of the lock portion 2 also passes through the fabric of the mailing pouch.

One skilled in the art will quickly conceive of many alternative means for fixing the lock portion 2 to a mailing pouch. Different arrangements of projections and holes, or alternative means, such as gluing or stitching a suitable flange on the body of the lock portion 2 to the fabric, may be used. For example, the fixing plate 4 and the lock portion 2 may have corresponding holes and be fixed together using rivets. In one embodiment, the fixing plate 4 has hooked projections which snap-fit into appropriate recesses in the lock portion 2.

The lock portion 2 is attached to the fabric of a mailing pouch near to a zipper, in a position whereby, when the zipper is fully closed, a zipper tag 3 attached to the zip slider can sit in the tray 25 in the lock portion 2. The zip slider sits in the recess 27 of the lock portion 2 and is protected from tampering.

The seal 1 is adapted to retain a zipper tag 3 in the tray 25 of the lock portion 2. The zipper tag 3 is planar and shaped to fit into and fill the tray 25 of the lock portion 2. One end of the zipper tag 3 is adapted for attachment to a zip slider. The zipper tag has a hole 31 through it. The hole 31 is positioned to overlie the mouth 23 of the bore 21 in the lock portion 2 when the tag 3 is sitting in the tray 25. The hole 31 is large enough to allow the feet 14 of the seal 1, but not the head 11 of the seal 1 to pass through.

The seal 1, lock portion 2, fixing plate 4 and zipper tag 3 are each moulded from plastics material using conventional injection moulding techniques.

The use of the sealing device will now be described with reference to Figures 2 and 3. Prior to use, the mailing pouch, which is equipped with the lock portion 2 of the sealing device described above, is filled and the zipper closed. The zipper tag 3 is placed in the tray 25 on the lock portion 2, as shown in Figure 2.

A seal 1 is inserted, legs 13 first, through the hole 31 in the zipper tag 3 and into the bore 21 in the lock portion 2. Force is applied to the seal, in the axial direction of the bore 21, by a user's thumb or finger pressing against the head 11 of the seal 1. As the legs 13 of the seal 1 enter the bore 21, the feet 14 engage with the guide 22 in the bore 21. Continued application of force causes the seal 1 to turn about its axis, as it progresses along the guide into the bore 21. As it does so, the legs 13 are forced together by the decreasing diameter of the bore 21. On full insertion, the seal will have rotated through 90° and the feet 14 will protrude from the end of the bore 21, allowing the legs 13 to spring back to their original form, hooking the feet 14 behind the shoulder 24 of the lock portion 2. In the preferred embodiment, the complementary shapes of the feet 14 and shoulder 24 ensure that the legs 13 cannot be withdrawn from the lock portion 13. It will be appreciated that although the seal 1 is free to rotate within the bore 21, it is not possible to re-engage the legs 13 with the guide 22, and so the seal 1 cannot be removed. In the preferred embodiment, the legs are slightly longer than the bore in order to ensure that the outer edge 15 of the feet 14 extends past the inner edge of the shoulder 24. This ensures proper snap-fit engagement of the feet 14 and the shoulder 24 and the resulting small amount of play between the seal 1 and the lock portion 2 facilitates rotation of the seal. It has been found that on full insertion, the legs rotate away from alignment with the guide 22, thus further frustrating any attempt to remove the seal 1 without damage.

In order to release the zipper tag 3, a finger is inserted under the zipper tag 3, possibly extending into the small recess 28. The end of the zipper tag 3 is pulled away from the lock portion 2. This places an upward force on the seal head 11, sfraining the frangible neck 12 until the head 11 breaks away from the legs 13. The head 11 falls away from sealing device and the legs fall through the bore 21 in the lock portion 2 into the mail pouch. The zipper tag 3 is thus released and the zip may be opened.

An alternative form of seal, for use with the above-described lock portion is substantially similar to the seal 1 previously described but it comprises only one pair of opposed legs. Again, the legs resemble a slotted tube, but in this embodiment the tube has only two slots on its circumference, positioned opposite each other. Use of two legs reduces the complexity of the seal 1, facilitating moulding, but four legs 13 (and four feet 14) provide additional grip to the snap-fit locking arrangement, enhancing the strength of the sealing device. Furthermore, a two legged seal tends to rock sideways, possibly damaging the seal, as it is initially inserted into the bore 21 but a four legged seal 1 has better initial stability and more readily locates in the guide 22.

It will be appreciated that whilst the seals of the described embodiments have two and four legs 13, it would be possible to have other numbers of legs, such as three legs, provided the lock portion has a guide 22 with an appropriate number of guide channels (see below). An alternative seal 1, not shown, may comprise a single leg with a pair of opposed, resiliently deformable feet which may, for example, fold up substantially parallel to the leg to allow insertion into the lock portion 2.

The arcuate cross section of each leg 13 in both of the described seals provides additional rigidity without increasing the volume of material used to make it. However, in other embodiments, the cross section of the each leg 13 may be any appropriate shape, in particular rectangular or semi-circular.

In the preferred embodiment, the head 11 of the seal 1 is disk shaped but the head 11 may be any shape to fulfil the function of concealing the mouth of the bore 21 of the lock portion 2. Thus, the head 11 need not be planar but could be, for example, spherical, cuboid or pyramid shaped.

In the preferred embodiment, the legs 13 are joined together and all joined to the head 11 by a single frangible neck 12 but they may be individually joined to the head 11 by separate frangible connections.

The wedge shape of each foot 14 facilitates pushing the seal 1 into the lock portion 2, although any shape with an appropriate sloping face will provide this benefit and flat faced feet 14, although not preferred, can be used. The inclination of the feet relative to the legs, so that the remote edge 15 of each foot is nearer to the head 11 when measured along the axis of the seal 1, enhances the engagement between the foot 14 and the lock portion 2, although in an alternative, less preferred embodiment, the top face of the foot 14 may extend perpendicular to the leg 13. The shape of the tray 25 can be varied according to the shape of the tag 3. The recesses are not essential but, in use, the large recess 27 provides tamper protection for the zip slider and the small recess 28 facilitates lifting the tag 3 from the tray after the sealing device has been broken open. The sealing device is described in connection with a zip slider but it will be appreciated that such a sealing device might be used in conjunction with other sealing means. For example, the tag 3 might be attached to a flap of material which folds down to cover the opening of a bag.

The number of guide channels should be equal to or an exact multiple of the number of feet 14 on the associated seal 1 so that the seal can properly engage with the thread. The use of four channels and four feet 14 in the preferred embodiment means that the initial rotational orientation of the seal 1 relative to the guide 22 is not critical and a user can easily engage the seal 1 and the lock portion 2.

The pitch of the channels is quite course in order to facilitate insertion of the seal 1 into the lock portion 2. It has been found that a 90° rotation of the seal 1 as it enters the lock portion 2 is sufficient to prevent access to the feet 14 and improve the security provided by the sealing device but more or less rotation may be used as desired.

The tapering of the bore 21 facilitates insertion of the seal but a constant diameter bore 21 may be used, provided it is smaller than the usual distance between the remote ends of the feet 14.

In the preferred embodiment, the shoulder 24 is at the end of the bore 21 to facilitate manufacture but the shoulder 24 may be part way down the bore 21 so long as the legs 13 are long enough to push the feet 14 past it. The slope on the shoulder 24 facihtates engagement with the corresponding slopes on the feet 14 but a shoulder 24 perpendicular to the axis of the bore 21 may be used. However, a perpendicular shoulder is more susceptible to the feet 14 slipping over it and consequently the sloping shoulder 24 described above is preferred.

In the described embodiment, the lock portion 2 is re-useable because the legs 13 broken from an opened seal 1 are able to fall out of the bottom of the bore 21, providing space for a new seal 1 to be inserted. However, in an alternative embodiment of the lock portion 2, the bore can be closed at the bottom, such that the legs 13 of the seal 1 cannot be removed from the lock portion 2 even after the head 11 is broken away to open the sealing device. In this embodiment, both the seal 1 and lock portion 2 are designed to be disposable items. The bore 21 may be closed as a result of the mould used to form the lock portion 2, by a separate plug or by an adaptation to the back plate 41.

The invention is not restricted to the details in the foregoing embodiments but includes all such variations, modifications and equivalents which fall within the scope of the following claims.

Claims

CLAIMS:

1. A sealing device comprising: a lock portion; and a seal adapted to be inserted into the lock portion to a position of snap-fit engagement therewith, wherein the lock portion includes a guide which engages with and rotates the seal as it is inserted into the lock portion.

2. A lock portion for a sealing device as claimed in claim 1, wherein the guide is in the form of at least one spiral channel.

3. A lock portion as claimed in claim 2, wherein the lock portion has a bore therein and a step change in the diameter of the bore forms a shoulder.

4. A lock portion as claimed in claim 3, wherein the diameter of the bore is tapered from the mouth of the bore.

5. A lock portion as claimed in claim 3 or claim 4, wherein the shoulder is chamfered so that the inner circumference is further from the mouth of the bore than the outer circumference.

6. A lock portion as claimed in any one of claims 3 to 5, wherein the step-change in the diameter of the bore results from the bore passing right through the lock portion, so that the bottom of the lock portion forms the shoulder.

7. A lock portion as claimed in any one of claims 2 to 5, wherein the lock portion comprises a tray for locating a tag.

8. A lock portion as claimed in any one of claims 2 to 5, wherein the lock portion further comprises fixing means comprising holes for receiving extensions from a plate, wherein the plate is placed on one side of the material to which the lock portion is to be fixed with the extensions protruding through the material and into the holes in the lock portion.

9. A seal for a sealing device as claimed in claim 1, wherein the seal comprises: a head; a leg portion extending from the head; and one or more outwardly protruding foot or feet proximate the distal end of the leg portion, wherein each foot is adapted to engage with the guide so as to rotate the seal as it is inserted into the lock portion.

10. A seal as claimed in claim 9, wherein each foot is further adapted to provide snap-fit engagement with the lock portion.

11 A seal as claimed in claim 10, wherein the remote end of each foot of the seal is axially nearer the head of the seal than the connection between the foot and the leg portion.

12. A seal as claimed in any one of claims 9 to 11, wherein the leg portion of the seal comprises a plurality of resiliently deformable legs, each associated with a separate foot.

13. A seal as claimed in claims 12, wherein the legs are arcuate in cross section.

14. A seal as claimed in claims 12 or claim 13, wherein the leg portion of the seal resembles a tube with longitudinal slots spaced around its circumference.

15. A seal as claimed in any one of claims 12 to 14, wherein the leg portion comprises two legs.

16. A seal as claimed in any one of claims 12 to 14, wherein the leg portion comprises four legs.

17. A seal as claimed in any one of claims 9 to 16, wherein the head of the seal is a disk.

18. A seal as claimed in any one of claims 9 to 16, wherein the head of the seal is separated from the leg portion by a frangible neck

19. A sealing device comprising: a lock portion as claimed in any one of claims 3 to 8; a seal as claimed in any one of claims 9 to 18, wherein: the seal comprises at least two feet; and the distance between the remote edges of the feet is greater than the minimum diameter of the bore; the guide engages with the feet and rotate the seal as the legs enter the bore; and snap-fit engagement results when the feet, which move to allow insertion of the legs into the bore, latch behind the shoulder.

20. A sealing device comprising: a lock portion as claimed in any one of claims 3 to 8; a seal as claimed in any one of claims 9 to 18, wherein: the seal comprises at least two feet; and the external diameter of the guide tapers from approximately the usual distance between the remote edges of the feet at the mouth of the bore to approximately the minimum distance between the remote edges of the feet immediately before the shoulder.