WO2021148795A1

WO2021148795A1 - Security tag for attachment to an object and method of attaching a security tag

Info

Publication number: WO2021148795A1
Application number: PCT/GB2021/050136
Authority: WO
Inventors: Russell NAPTHINE
Original assignee: Sekura Global Ip Llp
Priority date: 2020-01-23
Filing date: 2021-01-22
Publication date: 2021-07-29
Also published as: GB202000982D0; GB2591269B; GB2591269A

Abstract

The present invention relates to security applied to an object in a retail environment to deter theft of the object. A security tag for attachment to an object to deter theft of the object comprises a main body comprising a base and a cover, the cover being moveable relative to the base between an open configuration and a closed configuration, and the cover being connected to the base in both the open and closed configurations; a closure mechanism configured to retain the cover in the closed configuration; a housing biasing member configured to urge the cover into the open configuration on release of the closure mechanism; circuitry housed in an interior of the main body, the circuitry comprising a cover switch, an alarm and a master switch; and a tamper element forming part of a tamper circuit.

Description

SECURITY TAG FOR ATTACHMENT TO AN OBJECT AND METHOD OF ATTACHING A SECURITY TAG

FIELD OF THE INVENTION

The present invention relates to security tags and in particular to electronic article surveillance (EAS) tags that are applied to items in a retail environment to deter theft of the items. In particular, the present invention relates to security tags that are reusable and may be detached from the item using a suitable detacher.

BACKGROUND TO THE INVENTION

There are a number of known systems for deterring or preventing theft of articles from a retail environment. Typically these systems include an electronic article surveillance (EAS) tag that is attached to the article or object in a retail store. While the EAS tag is activated, the tag is arranged to trigger an alarm if the tag, and therefore the article, passes between a pair of detection gates, which are typically positioned at the entrance and exit of the retail store.

EAS tags are usually deactivated at the point of sale so that the alarm is not triggered when the article is removed from the retail store. Some tags, often for use with lower-value items, are single-use, and remain on the object for disposal by the customer. Other tags are designed to be detached from the article in store, and then subsequently reused.

Systems used to allow detection of EAS tags are commonly known as electro magnetic (EM), acousto-magnetic (AM), or radio-frequency (RF) systems.

AM systems are commonly used in AM EAS labels, which are typically attached to smaller, lower cost items. When a customer purchases an article having one of these EAS labels attached to it, the label is deactivated by changing the magnetisation of part of the label so that the alarm is not triggered when that person leaves the retail store. The label, however, remains attached to the article and is, therefore, single use or disposable. Disadvantages of disposable EAS tags are that they generate waste and replacement tags may be costly.

Another known EAS tag is commonly referred to as a hard tag and includes an EAS element or sensor in a hard, or semi-rigid, plastic body. Such hard tags are typically physically or mechanically attached to an article by means of a pin, cable or lanyard. Traditionally, hard tags are applied to higher cost items and larger articles. When the article is purchased, the tag may be detached from the article by a detacher device located at the point of sale. One type of detacher operates by applying a suitable magnetic field to unlock the tag for removal, and optionally deactivate the tag. Hard tags that are deactivated and removed completely from the article may be re-usable.

The need, however, for tamper-proof designs and reliable operation of these security tags is often at odds with the efficient removal of the tags in store. Accordingly, attaching and removing some types of hard tags by store assistants at the point of sale may be time consuming, inconvenient and therefore costly to the retailer.

Against this background it is desirable to provide an improved reusable security tag that addresses at least one problem associated with the prior art, whether referred to herein or otherwise.

SUMMARY OF THE INVENTION

A first aspect of the invention provides a security tag for attachment to an object to deter theft of the object, the security tag comprising: a main body comprising a base and a cover, the cover being moveable relative to the base between an open configuration and a closed configuration, and the cover being connected to the base in both the open and closed configurations; a closure mechanism configured to retain the cover in the closed configuration; a housing biasing member configured to urge the cover into the open configuration on release of the closure mechanism; circuitry housed in an interior of the main body, the circuitry comprising a cover switch, an alarm and a master switch; and a tamper element forming part of a tamper circuit; wherein,

(i) in a first state the master switch is in a first state, the cover is closed such that the cover switch is in a first state and the alarm and the tamper circuit are activated, and a change in state of the tamper element triggers the alarm;

(ii) in a second state the master switch is in a first state, the cover is open such that the cover switch is in a second state and the alarm and the tamper circuit are deactivated, and a change in state of the tamper element does not trigger the alarm; and

(ii) in a third state the master switch is in a second state, the cover is closed such that the cover switch is in the first state and the alarm is deactivated, and a change in state of the tamper element does not trigger the alarm.

It will be appreciated therefore that, in use, the alarm is only activated when the cover of the tag is closed. Furthermore, the alarm is automatically deactivated when the cover is opened. The security tag is arranged to be opened at the point of sale in order to deactivate the alarm so that the tag can be removed from an object that has been purchased. Advantageously, opening the main body of the tag both deactivates the alarm and permits removal of the tag from the object, thereby allowing efficient removal of the tag at a point of sale.

In preferred embodiments the tamper element comprises an elongate flexible element. The tamper element may comprises a tape or strap. The tamper element preferably comprises an adhesive layer for securing the tamper element to an object.

In some embodiments the tamper element comprises an elongate conductive element and the circuitry includes a pair of conductive contacts, the conductive element being electrically connectable to the conductive contacts to form the tamper circuit. The conductive contacts are preferably accessible only when the cover is in the open position. Accordingly, the tamper element may only be attached to or detached from the conductive contacts when the cover is in the open configuration (and the alarm is deactivated).

The tamper element preferably comprises an insulating backing layer. The circuitry and the tamper circuit are preferably configured such that the alarm is triggered when the tamper element is broken.

Embodiments of the security tag preferably further comprise a clamping mechanism arranged to apply a force to regions of a tamper element connected to the conductive contacts when the cover is in the closed configuration. The clamping mechanism may comprise one or more projections arranged to contact the regions of a tamper element connected to the conductive contacts when the cover is in the closed configuration and to be separated from the regions of a tamper element connected to the conductive contacts when the cover is in the open configuration. In this way, the clamping mechanism ensures that a good electrical connection is maintained between the tamper element and the conductive contacts when the cover is closed. The clamping force is, however, preferably automatically released when the cover is opened to permit detachment of the tamper element from the conductive contacts.

In some embodiments the circuitry is preferably configured such that, when the cover is in the closed configuration, the alarm system is activated only if the tamper circuit is complete. In this way the main body of the security tag may be closed to protect the contents of the tag when the security tag is being stored.

The master switch may comprise at least one of the pair of conductive contacts. In other embodiments the master switch comprises a manual switch housed in the main body and the manual switch is inaccessible when the cover is in the closed position.

In some embodiments the tamper element is configured to detect a loss of contact between the main body and an object to which the security tag is attached. The tamper element may comprise a trigger member moveable between a first position and a second position.

To permit secure attachment of the main body of the tag to the object the base of the main body preferably comprises an adhesive layer. The adhesive layer may comprise a stretch release adhesive.

In preferred embodiments the cover is connected to the base by a hinge. Furthermore, the biasing member preferably comprises a torsion spring. The torsion spring is advantageously associated with the hinge so as to bias the cover into the open configuration.

The closure mechanism is preferably biased into a locked configuration arranged to retain the cover in the closed configuration. In preferred embodiments the closure mechanism is then releasable from the locked configuration using an external detacher. The detacher may be a magnetic detacher. In particularly preferred embodiments the closure mechanism comprises a pin and a ball clutch mechanism, and the pin is releasable from the ball clutch mechanism using an external magnetic detacher.

The cover switch preferably comprises a non-latching switch. In preferred embodiments the switch is configured such that the switch is depressed when the cover is in the closed configuration and the switch is released when the cover is in the open configuration.

A security tag according to an aspect of the present invention preferably further comprises an electronic article surveillance (EAS) sensor element. The EAS sensor element may be electrically connected to the alarm.

The circuitry preferably comprises a buzzer configured to sound when the alarm is triggered. The circuitry may also include a visual indicator such as a light emitter.

A second aspect of the present invention provides a method of attaching a security tag to an object to deter theft of said object, the security tag being according to the first aspect of the invention, and the method comprising: attaching the main body of the security tag to the object with the cover in the open configuration; and moving the cover into the closed configuration to switch the cover switch to the first state and activate the alarm of the security tag.

In some embodiments the method preferably comprises attaching a first region of the tamper element to a first one of the conductive contacts, wrapping the tamper element around said object, and attaching a second region of the tamper element to a second one of the conductive contacts.

A third aspect of the present invention provides a method of removing a security tag from an object, the security tag being according to the first aspect of the invention, and the method comprising: applying a detacher to the main body of the security tag to release the closure mechanism such that the biasing member automatically urges the cover into the open configuration; and detaching the main body from the object.

In some embodiments the method preferably comprises, after releasing the closure mechanism, disconnecting regions of the tamper element from the conductive contacts.

Preferred and/or optional features of each aspect and embodiment described above may also be used, alone or in appropriate combination, in the other aspects and embodiments also.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a security tag according to a first embodiment of the invention, showing a main body and a tamper element of the security tag, together with a box to which the security tag is attached;

Figures 2A and 2B show opposing first and second sides, respectively, of part of the tamper element of Figure 1 ;

Figure 3 is a perspective view of the main body of the security tag of Figure 1 ; Figure 4 is a side view of the main body of Figure 3;

Figure 5 is a cross-sectional view of the main body of Figure 3, along the line V-V;

Figure 6 is a perspective view of the main body of Figure 3 showing a cover of the main body in an open position, with contents of the main body removed;

Figure 7 is a plan view from above of the main body of Figure 3;

Figure 8 is a view of the main body of Figure 3, with the cover in the open position, showing circuitry, an alarm system and an electronic article surveillance (EAS) sensor element of the security tag;

Figure 9 is a view from above of the main body of Figure 8, with the cover in the open position, showing in particular circuitry and conductive contacts of the security tag;

Figure 10 is a side view of the main body of Figure 8, with the cover in the open position;

Figure 11 is a plan view from above of a main body of a security tag according to a second embodiment of the invention;

Figure 12 is a cross-sectional view of the main body of Figure 11 along the line XII- XII, showing a circuit board and light emitter of the security tag; Figure 13 is a cross-sectional view of the main body of Figure 11 along the line XIII- XIII, showing part of a closure mechanism of the security tag;

Figure 14 is a cross-sectional view of the main body of Figure 11 along the line XIV- XIV; and

Figure 15 illustrates a main body of a security tag according to a third embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a security tag for deterring theft of an object. The security tag comprises a main body and a tamper element. An alarm system and associated circuitry is housed in the main body of the tag and is connected to the tamper element. The tamper element is securable to or engageable with the object such as a box or other packaging. In some embodiments the tamper element is configured such that the object cannot be opened or used without breaking or damaging the tamper element.

In use, the security tag is secured to the object and the alarm system is activated. If a person attempts to remove the tag from the object or to open the object by breaking or damaging the tamper element the alarm is triggered. Preferably the alarm is an audible alarm. When a person purchases the object the alarm system is deactivated. At least the main body of the tag can then be removed from the object without triggering the alarm.

The security tag is configured such that opening the main body of the tag automatically deactivates the alarm system. In some embodiments the main body of the tag is configured to be opened to also permit separation of the main body from the tamper element. The tag may be arranged such that opening the main body both disarms the alarm system and allows release or detachment of the tamper element from the main body. The main body of the tag may therefore be configured to be deactivated and removed from the object at the point of sale whilst leaving the tamper element attached to the object. In other embodiments the tamper element may remain attached or connected to the main body of the tag.

The tag is generally configured to be easily and promptly deactivated and detached from an item by a store assistant and the tag may then be conveniently reattached to another item for reuse.

A security tag 10 according to a first embodiment of the invention is shown in Figures 1 to 10.

Referring to Figure 1 , in this embodiment the security tag 10 is designed to be applied to a box 2 and to deter or prevent opening of the box 2 while the security tag 10 is activated. It will be appreciated, however, that in other embodiments the security tag 10 may be attached to other objects or items.

The security tag 10 comprises a main body 12 and a tamper element 14. The tamper element 14 is arranged to be connected to the main body 12.

The tamper element 14 is preferably in the form of an elongate flexible member such as a cord, a strap or a length of tape. In this embodiment the tamper element 14 comprises an elongate flexible tape that may be wrapped around the box 2. Preferably the tape is an adhesive tape so that it may be adhered to a surface of the box 2 to further hinder removal of the security tag 10 from the box 2. The adhesive tape may comprise a reusable adhesive. The tamper element 14 includes an electrically conductive element 18 extending along the full length of the tamper element 14. The conductive element 18 may be in the form of a metallic strip or metallic wire.

In this embodiment, the tamper element 14 is in the form of an elongate tape comprising an electrically insulating backing layer 15 having a first side 16 and an opposite second side 17, as shown in Figures 2A and 2B. An electrically conductive strip 18 is provided on the first side 16 of the backing layer 15. The first side 16 of the backing layer 15 also includes an adhesive region 22. The first side 16 of the backing layer 15 (together with the conductive strip 18 and the adhesive region 22) forms a first side 19 of the tamper element 14. The second side 16 of the backing layer 15 forms a second side 20 of the tamper element. The conductive strip 18 is exposed so as to provide a conductive surface extending along the length of the tamper element 14. In this first embodiment, the conductive strip 18 is a central strip which extends longitudinally along a length of the tape and adhesive regions 22 are disposed on either side of the conductive strip 18, adjacent longitudinal edges of the tape. In other embodiments, the tamper element 14 may comprise more than one conductive strip. In use, the first side 19 of the tamper element 14 is adhered to an item and the conductive strip 18 is therefore fully covered and protected by the insulating backing layer 15.

In some embodiments, the conductive element may not be exposed along the full length of the tamper element. Instead, parts of the conductive element may be exposed adjacent ends of the tamper element in order to electrically connect with the conductive contacts. For example, the tamper element may comprise a removable insulating layer which shields the conductive element and which is arranged to be removed in the regions of the tamper element that are secured to the conductive contacts.

Referring to Figures 3 to 6, the main body 12 of the security tag 10 comprises a base 24 and a cover 26. The base 24 and cover 26 together define a housing having a hollow interior 28, as seen clearly in Figures 5 and 6. The cover 26 and base 24 are preferably configured such that the cover 26 may be moved relative to the base 24 to access the interior volume 28 of the housing. The cover 26 is movable between a first, closed position in which the interior 28 of the housing cannot be accessed, and a second open position in which the interior 28 of the housing is accessible. The open position corresponds to an open configuration of the security tag 10 and the closed position corresponds to a closed configuration of the security tag 10. Figures 1 , 3, 4, 5, 7 and 11 show the first embodiment of the security tag 10 in the closed configuration and Figures 6 and 8 to 10 show the first embodiment of the security tag 10 in the open configuration. The base 24 comprises a base plate 30. In this embodiment the base plate 30 is substantially rectangular and includes a first, outer surface 31 and a second, inner surface 32. The base plate 30 of the security tag 10 is preferably provided with an adhesive layer on the outer surface 31 to enable the base plate 30, and therefore the main body 12 of the tag 10, to be adhered to an object such as a box 2. The base plate 30 may comprise a continuous adhesive layer or discrete adhesive regions. The adhesive layer may comprise a reusable adhesive. In this embodiment, the adhesive layer comprises an adhesive sheet 34 applied to the outer surface 31 of the base plate 30. As can be seen in Figures 3, 4 and 5, the adhesive sheet 34 comprises a tab 36 to facilitate removal of the tag 10 from an item. In this first embodiment, the adhesive sheet comprises a stretch release adhesive sheet 34. In use, the security tag 10 may be removed from a surface by using the tab 36 to pull (and therefore release) the stretch releasing adhesive. This allows the main body 12 of the tag 10 to be separated cleanly from the object. Preferably no adhesive of the adhesive regions remains on the object after detaching the base plate 30.

In other embodiments the base plate or the main body of the security tag may comprise other means to attach or affix the main body of the tag to an object. These other means may comprise, for example, a strap, a band, or a mechanical fastener.

Referring to Figures 3 and 6, the cover 26 comprises a generally rectangular top plate 38, a front wall 40, a rear wall 41 , a first side wall 42 and a second side wall 43. The walls extend perpendicularly away from respective edges of the top plate 38 towards a rim 44. The walls 40, 41 , 42, 43 preferably extend continuously around a perimeter of the top plate to form a complete perimeter wall 46. When the security tag 10 is in the closed configuration, the perimeter wall 46 extends between the top plate 38 and the base plate 30, such that the rim 44 abuts an edge region 48 of the base plate 30. In this way, the base plate 30, top plate 28 and perimeter wall 46 enclose the interior 28 of the tag 10.

In this embodiment the cover 26 is hingedly secured to the base 24. The cover 26 is secured to the base plate 30 along one edge of the generally rectangular base plate 30 by a suitable hinge 50. Referring additionally to Figure 7 and 10, in this embodiment the hinge 50 connects the rear wall 41 of the cover 26 to a rear edge 47 of the base plate 30. The hinge 50 is arranged to allow the cover 26 to pivot relative to the base plate 30, such that the cover 26 can be moved relative to the base plate 30 between the open position and the closed position. In this way, the cover 26 and base 24 remain connected when the cover 26 is in the open position.

The base plate 30 and the cover 26 are preferably formed from a suitable rigid material. Preferably the base plate 30 and the cover 26 are formed from a polymeric material.

It is advantageous if the cover 26 cannot be easily opened by unauthorised persons once it has been closed, in order to prevent tampering with the contents of the main body 12. The rigid material of the cover 26 helps to prevent access to the contents of the main body 12. Additionally, the security tag 10 is preferably provided with a closure mechanism 52, which is configured to retain the cover 26 in the closed position and which can only be released using a suitable detacher, as described below. In this way, without a detacher, the interior 28 of the tag 10 cannot be accessed without causing damage to the main body 12. The closure mechanism 52 is preferably biased into a locked configuration in which the cover 26 is held in the closed position and the cover 26 cannot be moved into the open position. The detacher may be used to move the closure mechanism 52 into a released configuration in which the cover 26 can be moved into the open position.

In this embodiment, the closure mechanism 52 comprises a latch mechanism 54 and a retaining catch 56, as can be seen most clearly in Figure 5. In the locked configuration the latch mechanism 54 is retained by the retaining catch 56, such that opening of the cover 26 is prevented. The latch mechanism 54 is releasable from engagement with the retaining catch 56 using a detacher, such that the closure mechanism 52 moves into the released configuration and the main body 12 of the tag 10 can be opened. The main body 12 of the tag 10 is then removable from the object, for example at the point of sale. In this embodiment, the latch mechanism 54 is arranged to be released by a magnetic detacher. In this embodiment, the latch mechanism 54 is mounted in the cover 26, and the retaining catch 56 is connected to the base 24. In other embodiments the latch mechanism may be mounted in the base and the retaining catch may be mounted in the cover.

The latch mechanism 54 preferably comprises a mounting body 58, a closure member 64, and a latch biasing member 76. As can additionally be seen in Figure 8, in this embodiment, the mounting body 58 is generally tubular and extends away from an inner surface of the top plate 38. The mounting body 58 is seated in a region of the top plate 38 adjacent the front wall 40. In particular, the mounting body 58 extends from a recessed portion 60 of the inner surface of the top plate 38. A corresponding boss 62 is formed on an outer surface of the top plate 38.

Referring again to Figure 5, in this embodiment the closure member 64 comprises a hook 64 having a base portion 66, a tip 68, and a shank 70 extending between the base portion 66 and the tip 68. The tip 68 of the hook 64 projects from a distal end of the shank 70. In this embodiment the tip 68 is curved, and in particular includes a curved outer surface 72. In other embodiments the tip 68 may be in the form of a barb. The hook 64 is mounted in the mounting body 58 such that the base portion 66 is closest to the top plate 38 of the cover 26, the shank 70 extends away from the top plate 38, and the tip 68 of the hook 64 extends towards the front wall 40. With the main body 12 in the closed configuration, the hook 64 extends towards the base plate 30. The hook 64 is pivotally mounted to the mounting body 58. In this embodiment, the hook 64 is mounted by a pivot pin 74 which extends through the base portion 66 of the hook 64 and is secured to the mounting body 58. The hook 64 is arranged to pivot about the pivot pin 74 such that the tip 68 of the hook 64 moves towards or away from the front wall 40. Preferably a rotational or pivot axis extends substantially parallel to a plane of the top plate 38 of the cover 26.

The biasing member 76 is arranged to bias the latch mechanism 54 into engagement with the retaining catch 56. In this embodiment, the biasing member 76 comprises a compression spring 76 disposed between the base portion 66 of the hook 64 and the recessed portion 60 of the top plate 38. The spring 76 is arranged to contact a part of the base portion 66 on an opposite side of the pivot pin 74 to the hook tip 68, such that the spring 76 urges the hook 64 to rotate about the pivot pin 74 in a first direction such that the hook tip 68 moves towards the front wall 40. Pivoting of the hook 64 in this first direction is limited by a stop member 77, which extends from the front wall 40 towards the hook 64. In particular, rotation of the hook 64 in the first direction is limited by abutment of the shank 70 of the hook 64 with the stop member 77.

The retaining catch 56 extends from the base plate 30 adjacent a front edge 45 of the base plate 30. With the main body 12 in the closed configuration, the retaining catch 56 is disposed between the hook 64 and the front wall 40. The retaining catch 54 comprises a stem 78 and a barb 80. The barb 80 extends from the stem 78 in a direction generally away from the front edge 45 of the base plate 30. The barb 80 comprises a ramped surface 82 which faces generally away from the base plate 30, and a retaining surface 84 which faces generally towards the base plate 30. The barb 80 preferably has a shape that is complementary to the shape of the tip 68 of the hook 64.

In use, as the cover 26 is closed, the curved outer surface 72 of the tip 68 of the hook 64 is deflected by the ramped surface 82 of the barb 80. The angle of the ramped surface 82 of the barb 80 is such that the hook 64 is urged to rotate in a second direction, opposite to the first direction, about the pivot pin 74. The hook 64 rotates in the second direction against the biasing force of the spring 76. When the tip 68 reaches the end of the ramped surface 82, the spring 76 urges the hook 64 to rotate in the first direction such that the tip 68 engages with the retaining surface 84 of the barb 80. The hook 64 is therefore retained by the barb 80 such that the cover 26 of the main body 12 cannot be opened, and the closure mechanism 52 is in its locked configuration.

To allow the cover 26 to be moved into the open position, it will be appreciated that the tip 68 of the hook 64 must be disengaged from the barb 80. In this embodiment the hook 64 must therefore be rotated in the second direction against the force of the spring 76. To achieve this the closure mechanism 52 is configured to be released using a suitable detacher that applies the required force to the hook 64. In this embodiment, the base portion 66 of the hook 64 comprises a magnetic material. A preferred detacher is then configured to apply a suitable magnetic field in the proximity of the base portion 66 of the hook 64. This causes the base portion 66 of the hook 64 to be urged towards the top plate 38 of the cover 26, which in turn causes the hook 64 to pivot about the pivot pin 74 against the force of the spring 76. In this way, the tip 68 is disengaged from the barb 80 in order to release the closure mechanism 52.

The boss 62 provided on the outer surface of the cover 26 provides an external indication of the internal position of the latch mechanism 54. In this way, application of a magnetic field can be targeted towards the boss 62 in order to apply a suitable magnetic field to the hook 64 within the tag 10. In use, a suitable magnetic detacher is used to apply a magnetic field to release the closure mechanism 52. It will be appreciated that the base portion 66 of the hook 64 may include any suitable magnetic material or metallic material. The base portion 66 of the hook 64 may include a ferromagnetic material.

Release of the closure mechanism 52 allows the main body 12 of the tag 10 to be opened. Advantageously the main body 12 of the tag 10 is biased or urged into the open configuration. In this way, when the detacher is used to disengage the closure mechanism 52, the cover 26 will automatically move into the open position, without requiring a further action by the user of the tag 10.

The main body 12 comprises a housing biasing member 86 arranged to urge the cover 26 into the second, open position. The biasing member 86 is preferably housed within the interior 28 of the main body 12. In preferred embodiments the biasing member 86 is in the form of a spring 86 which acts between the base 24 and the cover 26 of the main body 12. The housing biasing member 86 preferably comprises a torsion spring 86 mounted on a pivot pin of the hinge 50, as can be seen clearly in Figures 6 and 9. A first arm 88 of the torsion spring 86 contacts a part of the cover 26 and a second arm 90 of the torsion spring 86 contacts a part of the base 24. The torsion spring 86 is arranged to apply a force to the cover 26 and base 24 such that the cover 26 and base 24 are urged to pivot about the hinge 50 into the open configuration. In some embodiments, the main body may include more than one torsion spring. In other embodiments, the biasing member 86 may comprise a leaf spring, coil spring or other suitable biasing means.

Conveniently, when the closure mechanism 52 is released, the torsion spring 86 urges the cover 26 into the open position. In this way, a user need not manually open the tag 10 once a magnetic field has been applied using the detacher, as the tag housing will open automatically, and access to the interior 28 of the main body 12 is thereby provided. The tamper element 14 may then be detached from the main body 12 (as described further below) and the tag 10 may then be removed from the item. The cover 26 and base 24 remain connected by the hinge 50, which limits the number of separate parts handled by the user. In this way, the main body 12 of the tag 10 comprises a ‘one-piece’ assembly that may be removed from a tagged item conveniently.

In the present invention, opening of the main body 12 disarms an alarm system of the tag 10 and in this embodiment allows the tamper element 14 to be detached from the main body 12 of the tag 10. The main body 12 of the tag 10 may then be removed from the object.

As shown in Figures 8 to 10, the security tag 10 comprises circuitry 92 housed in the interior 28 of the main body 12. The circuitry 92 comprises an alarm system which in this embodiment is configured to be triggered when the tamper element 14 is damaged. The alarm system may also be configured to be triggered by unauthorised removal of the tag 10 (and therefore the object to which it is attached) from a retail store or similar.

In this embodiment the circuitry 92 comprises a circuit board 94, a power source 96, a microcontroller 98, a cover switch 100, a buzzer or sounder 102 and a pair of conductive contacts or contact pads 104, 106. As can be seen in Figures 8 to 10, the circuit board 94 is mounted on the base plate 30 and supports the power source 96, microcontroller 98, cover switch 100, buzzer 102 and conductive contacts 104, 106.

The power supply 96 preferably comprises one or more batteries. The battery or batteries may be replaceable, such that the operating lifetime of the tag can be extended, as may be required if the tag is reused.

A first one 104 of the pair of conductive contacts 104, 106 is disposed proximate a first side edge of the base plate 30. A second one 106 of the pair of conductive contacts 104, 106 is disposed proximate an opposite second side edge of the base plate 30. There is a gap 110 between the first and second conductive contacts 104, 106 within the housing. The conductive contacts 104, 106 are arranged to electrically connect to the tamper element 14. In particular, in use, a first region or first end of the tamper element 14 is electrically connectable to the first conductive contact 104 and a second region or second end of the tamper element 14 is electrically connectable to the second conductive contact 106. When the tamper element 14 is connected to the conductive contacts 104, 106 a tamper circuit is formed. The tamper circuit is electrically connected to an alarm circuit of the security tag 10. The alarm circuit is configured to trigger an alarm when the tamper circuit is broken.

In this embodiment, the first and second regions of the tamper element 14 are secured to the contacts 104, 106 by the adhesive layer 22 on the first side 19 of the tamper element 14, such that the exposed conductive strip 18 of the tamper element 14 contacts the conductive contacts 104, 106, to complete the tamper circuit. The adhesive layer 22 is arranged such that the first and second regions of the tamper element 14 can be readily detached or unpeeled from the conductive contacts 104, 106 when it is desired to detach the tag 10 from the object.

Importantly, the tamper element 14 is secured to the conductive contacts 104, 106 such that the conductive strip 18 of the tamper element 14 does not electrically connect the first and second conductive contacts 104, 106 across the gap 110 between the first and second conductive contacts 104, 106 within the housing. In preferred embodiments the security tag 10 includes a clamping mechanism that applies a force to each of the first and second regions of the tamper element 14 to maintain the electrical contact between the tamper element 14 and the conductive contacts 104, 106. In this first embodiment, the conductive contacts 104, 106 face away from the base plate 30, and towards the cover 26 when the cover 26 is in the closed position. A clamping projection 112 extends from an inner surface of the cover 26. The clamping projection 112 is aligned with and extends towards the conductive contacts 104, 106 when the cover 26 is closed. In this way, when the first and second regions of the tamper element 14 are disposed on the conductive contacts 104, 106, the clamping projection 112 is arranged to clamp the first and second regions of the tamper element 14 against the conductive contacts 104, 106. In particular, the clamping projection 112 is arranged to press the conductive strip 18 of the tamper element 14 against the conductive contacts 104, 106.

In some embodiments a pair of clamping projections are provided. In these embodiments a first projection is preferably aligned with the first conductive contact and a second projection is preferably aligned with the second conductive contact.

The clamping mechanism may further include a guide member which is arranged to locate between the conductive contacts, so as to guide placement of the cover into the closed position and to bring the or each of the clamping projections into engagement with the regions of the tamper element in contact with the conductive contacts.

It will be appreciated that when the cover 26 is moved into the open position, the clamping projection 112 is moved away from the conductive contacts 104, 106. The clamping projection 112 therefore no longer applies a force to the tamper element 14, thereby allowing the tamper element 14 to be separated from the conductive contacts 104, 106.

In some embodiments, the first and second regions or ends of the tamper element may be secured to the conductive contacts only by the adhesive portions. In other embodiments, the first and second regions or ends of the tamper element may be magnetically secured to the contacts, or by any other suitable mechanism, such as clips, clamps or other suitable fasteners.

The cover switch 100 is arranged to control power supply to components of the circuitry 92. The cover switch 100 is arranged to control the alarm circuit. The cover switch 100 is switchable between a first state, in which the alarm circuit is activated, and a second state, in which the alarm circuit is deactivated or disarmed. In this embodiment, when the cover switch 100 is in the first state such that the alarm circuit is activated, if the tamper element 14 is broken so as to open the tamper circuit, the alarm circuit is triggered. The alarm circuit preferably further comprises the buzzer or sounder 102. The buzzer 102 is configured to emit an audible sound when the alarm circuit is triggered.

In this embodiment, the cover switch 100 comprises a push switch or non-latching switch 100. The cover switch 100 comprises a button or plunger 101 which extends away from the base plate 30. The cover switch 100 is a ‘push to make’ switch configured such that whilst the button 101 is depressed or actuated, the cover switch

100 is in the first state and when the button 101 is released, the cover switch 100 is in the second state. In use therefore, the alarm circuit is activated whilst the button

101 is depressed and the alarm circuit is deactivated when the button 101 is released.

A lug 114 preferably projects from an inner surface of the cover 26. In use, the lug 114 is arranged to contact the button 101 when the cover 26 is closed. In this way, the lug 114 acts to actuate the cover switch 100 by depressing the button 101 whilst the cover 26 is closed. When the cover 26 is opened, the lug 114 is moved away from the cover switch 100 and the button 101 is released. Accordingly, the alarm circuit is activated whilst the security tag 10 is in the closed configuration, with the cover 26 in the closed position, and the alarm circuit is deactivated when the cover 26 is opened and the security tag 10 is in the open configuration.

In this first embodiment, the security tag 10 further comprises an electronic article surveillance (EAS) sensor element 116. The EAS sensor element 116 forms part of an EAS detection system, as is known in the art. In particular, and as will be understood by a person skilled in the art, the EAS sensor element 116 allows the security tag to be detected by suitable detection gates that may be installed at the entrance and exit of a retail store.

In preferred embodiments, the EAS sensor element is an acousto-magnetic (AM) sensor element comprising a strip or bar of a ferrite material. As can be seen in Figure 8, in this embodiment the AM element 116 is mounted in the cover, adjacent a side wall.

The EAS sensor element 116 is electrically connected to the circuitry 92. In preferred embodiments the EAS element 116 forms part of a sensor circuit. The sensor circuit is configured to detect when the EAS sensor element 116 is brought into proximity with suitable detection gates. Upon such detection, the sensor circuit is configured to trigger an alarm in the security tag 10. Accordingly, the sensor circuit is preferably linked to the alarm circuit. Alternatively, the circuitry 92 may comprise a second, auxiliary alarm circuit to which the sensor circuit is connected.

In some embodiments including an EAS sensor element 116, the security tag 10 is therefore configured to be triggered, and to emit an alarm, either by breaking the tamper circuit (by cutting or otherwise damaging the tamper element 14) or by bringing the tag 10 in proximity to a detector (such as a store exit detector gate) during unauthorised removal of the tag 10 from the store.

In use, the AM sensor element 116 may be deactivated at a point of sale, at the same time as the alarm circuit is deactivated by opening the cover 26 of the security tag 10. In preferred embodiments the sensor circuit is deactivated when the cover 26 of the main body 12 is opened. In particular, in some embodiments, the sensor circuit may be deactivated by releasing the cover switch 100. The cover switch 100 may control power supply to the sensor circuit. Therefore, if the security tag 10 is removed at the point of sale and is to remain in store, the AM sensor element 116 need not be deactivated separately by applying a magnetic field. Instead, opening the security tag 10 using a detacher as described above releases the cover switch 100, which in turn deactivates the sensor circuit, such that the AM sensor element 116 may no longer trigger an alarm in the security tag 10.

The microcontroller 98 (if present) may be configured to control a status of the alarm circuit (and the auxiliary alarm circuit if included) dependent on a status of the tamper circuit and/or the sensor circuit. For example, the microcontroller 98 may be configured to trigger an alarm when the tamper circuit is broken. Additionally or alternatively, the microcontroller 98 may be configured to trigger an alarm when the sensor circuit is activated by a detector. The microcontroller 98 may be connected to the cover switch 100.

The circuitry 92 may further comprise a status indicator in the form of a light emitter 118. The status indicator displays information concerning a state of the security tag 10. The light emitter 118 may be configured to emit light when the alarm circuit is activated and to turn off when the alarm circuit is deactivated or disabled. Alternatively the light emitter 118 may be configured to emit light when the alarm circuit is triggered. The light emitter 118 may be configured to change state when the alarm circuit is triggered. For example, the light emitter 118 may emit a constant light when the alarm circuit is activated and the light emitter 118 may flash when the alarm circuit is triggered. In embodiments including a light emitter 118, the cover 26 may include an aperture 120 which is aligned with the light emitter 118 when the cover 26 is in the closed position. Apart of the light emitter 118 may protrude through the aperture 120 when the cover 26 is in the closed position. In some embodiments, the light emitter may also indicate the status of other components of the security tag, such as battery life. In this embodiment, the light emitter 118 is in the form of a light emitting diode (LED) 118. In the closed configuration, the LED 118 is aligned with an aperture 120 in the cover 26.

In use, in this embodiment, the main body 12 of the security tag 10 is attached to an object with the tag 10 in the open configuration. A first end of a tamper element 14 is secured to the first conductive contact 104 so as to form an electrical connection. The tamper element 14 may then be wrapped around the object, and may additionally be adhered to the object. A second region of the tamper element 14, remote from the first end, is then secured to the second conductive contact 106.

In preferred embodiments the conductive strip 18 of the tamper element 14 is exposed only on the first side 19 of the tamper element 14 and is covered by an electrically insulating backing layer 15. Accordingly, the first side 19 of one part of the tamper element 14 may be adhered to the second side 17 of the backing layer 15 of another part of the tamper element 14 without forming a conductive loop. In use therefore, after the second region of the tamper element 14 has been secured to the second conductive contact 106 the tamper element 14 may continue to extend across the base 24 of the main body 12 and overlap the first end of the tamper element 14. A second end of the tamper element 14 may then extend from the main body 12. In this way, the second end of the tamper element 14 may be cut at a position remote from the main body 12.

The tamper element 14 therefore need not be cut to length precisely, as any excess can be overlapped without short-circuiting the tamper circuit. The tamper element 14 may therefore be applied quickly and conveniently to items of different dimensions. In particular, the tamper element 14 may be applied to an object directly from a roll of tape and then cut to the required length, for example.

The cover 26 of the tag 10 is then pivoted into the closed position against the force of the torsion spring 86. Closing the cover 26 acts to engage the closure mechanism 52 to prevent unauthorised opening of the cover 26. In preferred embodiments closing the cover 26 also simultaneously clamps the ends of the tamper element 14 against the conductive contacts 104, 106 by means of the clamping projection 112 and actuates the cover switch 100 to arm the alarm circuit by means of the lug 114 depressing the button 101.

It will be appreciated, therefore, that closing the main body 12 of the tag 10 automatically arms the alarm circuit, which in this embodiment is connected to both the tamper circuit and the sensor circuit. As such, the security tag 10 is activated to detect unauthorised removal of the tag 10 from the object by breaking the tamper circuit and to detect unauthorised removal of the tag 10 from the retail store.

At a point of sale, or other convenient location, the security tag 10 may be quickly and easily detached from the object.

Preferably, a suitable detacher, which as explained above may be a magnetic detacher, is applied to the security tag 10 to release the closure mechanism 52. The cover 26 is then urged into the open position by the housing biasing member (torsion spring) 86. This in turn releases the pressure on the cover switch 100 such that the power supply to the alarm circuit is disconnected. A user can then detach the tamper element 14 from the conductive contacts 104, 106 without triggering an alarm. The main body 12 of the security tag 10 can then be detached from the object.

In preferred embodiments the main body 12 of the security tag 10 is reusable and may be attached to another object as described above. It will be appreciated, however, that the main body 12 may not be attached to a second object immediately after removal from a first object. It is therefore desirable to be able to store the main body 12 of one or more tags 10 before re-use. It will also be appreciated that it is preferable if the main body 12 of the tag 10 can be stored in the closed configuration to prevent damage to the contents of the tag 10; however, in preferred configurations of the tag 10, the alarm circuit is armed when the cover 26 is closed. To overcome this problem, the circuitry 92 of the tag 10 is preferably configured such that the alarm circuit will not arm if the tamper circuit is not completed. In other words, the security tag 10 will not activate (i.e. the alarm circuit will not arm) if there is no tamper element 14 secured to and in electrical contact with the conductive contacts 104, 106. In embodiments in which the security tag 10 comprises a microcontroller 98, the microcontroller 98 may be configured to detect the presence of a complete tamper circuit, before enabling the alarm circuit.

In this way the main body 12 of the tag 10 preferably includes a tamper switch or master switch. When this master switch is in a first state the alarm circuit will arm if the cover is moved into the closed position, and when the master switch is in a second state the alarm circuit will not arm even if the cover is closed. As described above, in some embodiments the master switch comprises one or both of the conductive contacts such that the master switch remains in the second state until a tamper element is in electrical with the conductive contact at which time the master switch switches to the first state. In other embodiments the master switch may be provided by the microcontroller, when present. In yet further embodiments the main body may comprise a separate override switch which forms a master switch and which must be manually operated by a user when the cover is in an open position. The master switch is preferably not accessible when the cover is closed.

The tamper element 14 is preferably disposable. Accordingly, when the tag 10 is deactivated by opening the main body 12 and the tamper element 14 is detached from the conductive contacts 104, 106, the tamper element 14 may be left adhered or otherwise attached to the object. The main body 12, which is likely to be more expensive to replace, may then be reused with a new tamper element 14, which may be replaced more cheaply. In this way, the security tag 10 may be removed from an object more quickly.

Figures 11 to 14 show the main body 212 of a security tag 210 according to a second embodiment of the invention. The second embodiment is substantially identical to the security tag of the first embodiment and like features have been indicated with reference numerals incremented by 200.

The security tag 210 of this second embodiment is identical to the security tag 10 of the first embodiment except for the configuration of the closure mechanism. In this embodiment the closure mechanism comprises a pin and clutch mechanism, as is well known in the art.

In this embodiment, the clutch mechanism (not shown) is associated with the cover 226 of the main body 212 and the pin 322 is associated with the base 224 of the main body 212. In other embodiments the clutch mechanism may be associated with the base of the main body and the pin may be associated with the cover of the main body. Referring to Figures 12 and 13, the pin 322 is elongate and extends away from the base plate 230 adjacent the front edge 245. The pin 322 extends substantially perpendicular to the base plate 230. The clutch mechanism is provided in the cover 226 adjacent the front wall 240. The clutch mechanism is arranged to align with and receive part of the pin 322 when the cover 226 is in the closed position. The clutch mechanism is disposed in a clutch housing 324 which extends from a region of the top plate 238 adjacent the front wall 240. In this embodiment, the clutch housing 324 extends from a recessed portion 260 of the inner surface of the top plate 238. A corresponding boss 262 is formed on the outer surface of the top plate 238.

As is known in the art, the clutch mechanism is arranged to receive part of the pin 322 inserted into the clutch mechanism in a first direction, and prevent removal of the pin 322 from the clutch mechanism in an opposite second direction, until the clutch mechanism is released. The clutch mechanism preferably comprises a ball clutch (not illustrated). As is well known in the art, the housing of the ball clutch comprises a tapered, tubular retaining wall defining a substantially conical volume. The retaining wall contains, within the conical volume, means for gripping part of the pin 322. The gripping means comprises a plurality of ball bearings, an annular metal press plate and biasing means in the form of a spring, the annular press plate being positioned between the ball bearings and an end of the spring. The spring is arranged to urge the press plate and the ball bearings towards a narrower end of the conical volume. In this way, the ball bearings are urged radially inwardly towards one another as they are urged towards the narrower end of the conical volume by the spring.

The clutch mechanism is arranged such that, in use, when the cover 226 is moved into the closed position, the pin 322 is inserted into the conical housing from the narrower end. The pin 322 is pushed between the ball bearings and through the annular press plate, moving the ball bearings apart and moving the press plate in a first direction against the biasing force of the spring. The biasing force of the spring then urges the press plate in an opposite second direction which urges the ball bearings to grip part of the pin 322. If a force is applied to attempt to withdraw the pin 322 from the clutch mechanism, friction between the ball bearings and the pin 322, in addition to the biasing force of the spring, urges the ball bearings towards the narrower end of the conical volume, increasing the gripping force on the pin 322. In this way, removal of the pin 322 from the clutch mechanism is prevented.

In this embodiment, the clutch mechanism is arranged to be released using a suitable detacher, such that the pin 322 can be withdrawn from the clutch mechanism and the cover 226 moved into the open position. In this embodiment, the clutch mechanism is arranged to be released by application of a magnetic field, in a manner known in the art. To release the pin 322, a magnetic force is applied to the press plate to draw the press plate away from the narrower end of the conical volume, against the force of the spring. The force urging the ball bearings together to grip the pin 322 is therefore reduced, such that the pin 322 can be withdrawn from the clutch mechanism.

The remainder of the operation of the security tag 210 of the second embodiment and in particular the arrangement of the tamper circuit, alarm circuit and housing biasing member, are exactly as described in relation to the security tag 10 of the first embodiment, and will not be described further here.

In some embodiments, the security tag 210 may comprise a plunger or pressure pad coupled to a switch mechanism. In these embodiments the pressure pad or plunger is disposed on a lower surface of the base 224 of the main body 212 and is arranged to detect whether the base 224 of the main body 212 is in contact with the object to which the security tag 210 is attached. The pressure pad and switch mechanism are preferably arranged such that when the base 224 of the tag 210 is adhered to an object, the pressure pad contacts the item and the switch disarms an alarm system. If the tag 210 is pulled away or otherwise removed from the object, the switch mechanism is arranged to trigger an alarm in response to a loss of contact or pressure between the pressure pad and the object.

Figure 15 illustrates a security tag 410 according to a third embodiment of the invention. This third embodiment has many features that are identical or similar to features of the security tags 10, 210 of the first and/or second embodiments and like features have been indicated with reference numerals incremented by 400. The security tag 410 comprises a main body 412 and a tamper element 414. The tamper element 414 is connected to the main body 412.

The main body 412 of the security tag 410 comprises a base 424 and a cover 426. The base 424 and cover 426 together define a housing of the tag. The cover 426 and base 424 are preferably configured such that the cover 426 may be moved relative to the base 424 to access an interior volume of the housing. The cover 426 is movable between a first, closed position in which the interior of the housing cannot be accessed, and a second open position in which the interior of the housing is accessible. The open position corresponds to an open configuration of the security tag 410 and the closed position corresponds to a closed configuration of the security tag 410.

The base 424 and the cover 426 are preferably formed from a suitable rigid material. Preferably the base 424 and the cover 426 are formed from a polymeric material.

The base 424 comprises a base plate 430 including a first, outer surface 431 and a second, inner surface. The base plate 430 is preferably provided with an adhesive layer on the outer surface 431 to enable the base plate 430, and therefore the main body 412 of the tag 410, to be adhered to an object such as a box 2. The base plate 430 may comprise a continuous adhesive layer or discrete adhesive regions.

In this embodiment the cover 426 is hingedly secured to the base 424 by a suitable hinge 450. The hinge 450 is arranged to allow the cover 426 to pivot relative to the base 424, such that the cover 426 can be moved between the open position and the closed position. In this way, the cover 426 and base 424 remain connected when the cover 426 is in the open position.

Additionally, the security tag 410 is preferably provided with a closure mechanism, which is configured to retain the cover 426 in the closed position and which can only be released using a suitable detacher. The closure mechanism may be as described above in relation to the first embodiment or the second embodiment of the security tag. The closure mechanism preferably includes a latch mechanism. In preferred embodiments the closure mechanism is configured to be released by a suitable magnetic detacher. A boss 462 is preferably provided on an outer surface of the cover 426 to provide an external indication of the internal position of the closure mechanism and in particular the latch mechanism. In this way, application of a magnetic field can be targeted towards the boss 462 in order to apply a suitable magnetic field to release the closure mechanism.

Release of the closure mechanism allows the main body 412 of the tag 410 to be opened. Advantageously the main body 412 of the tag 410 is biased or urged into the open configuration. In this way, when the detacher is used to disengage the closure mechanism, the cover 426 will automatically move into the open position, without requiring a further action by the user of the tag 410. The main body 412 therefore preferably comprises a housing biasing member arranged to urge the cover 426 into the second, open position. The biasing member is preferably housed within the interior of the main body 412.

In this embodiment the tamper element 414 is in the form of a trigger member 522 that is slidably mounted in the main body 412 of the tag 410. The base plate 430 of the tag 410 comprises a hole that is sized to receive a part of the trigger member 522 therethrough. In this embodiment the trigger member 522 is an elongate rod and the rod is axially aligned with the hole in the base plate 430.

The trigger member 522 may be mounted in the base 424 of the main body 412, or alternatively the trigger member 522 may be mounted in the cover 426 of the main body 412. In embodiments in which the trigger member 522 is mounted in the cover 426, it will be appreciated that the trigger member 522 will align with and extend through the hole in the base plate 430 of the main body 412 when the cover 426 is in the closed position.

The trigger member 522 is moveable between a first, extended position and a second, engaged or retracted position. In the extended position a distal end portion of the trigger member 522 extends through the hole in the base plate 430 such that a distal tip 524 of the trigger member 522 protrudes from the outer surface 431 of the base plate 430. In the second position the tip 524 of the trigger member 522 does not protrude through the hole in the base plate 430. Typically, in the second position, the trigger member 522 will be maintained in a position such that a contact surface 526 of the trigger member 522 at its tip 524 is substantially flush with the outer surface 431 of the base plate 430.

The trigger member 522 is biased into the first, extended position. The biasing force is applied to the trigger member 522 by a suitable biasing member. The biasing member may be a spring, for example a compression spring, located between the trigger member 522 and a part of the housing of the main body 412 of the tag 410. It will be appreciated that the biasing member or spring may be of any suitable type and configuration to apply the required biasing force to the trigger member 522.

The security tag 410 comprises circuitry housed in the interior of the main body 412. The circuitry comprises an alarm system configured to be triggered when the tamper element 414 moves from a retracted position to an extended position as described below. The alarm system may also be configured to be triggered by unauthorised removal of the tag 410 (and therefore the object to which it is attached) from a retail store or similar.

The circuitry further comprises a cover switch, which preferably comprises a button or plunger which extends away from the base plate 430 towards the cover 426. The switch is a ‘push to make’ switch configured such that whilst the button is depressed or actuated, the switch is in a first state and when the button is released, the switch is in a second state. The button is arranged such that a part of the cover 426 contacts and depresses the button when the cover 426 is in the closed position.

In this way, the cover switch is actuated by depressing the button whilst the cover 426 is closed. When the cover 426 is opened the button is released. Accordingly, the alarm circuit is activated whilst the security tag 410 is in the closed configuration, with the cover 426 in the closed position, and the alarm circuit is deactivated when the cover 426 is opened and the security tag 410 is in the open configuration. The security tag 410 further comprises an electronic article surveillance (EAS) sensor element. The EAS sensor element forms part of an EAS detection system, as is known in the art. In particular, and as will be understood by a person skilled in the art, the EAS sensor element allows the security tag 410 to be detected by suitable detection gates that may be installed at the entrance and exit of a retail store.

In use, a user places the main body of the security tag 410 onto an object such that the outer surface 431 of the base plate 430 is in contact with a surface of the object. Contact between the surface of the object and the tip 524 of the trigger member 522 urges the trigger member 522 from the extended position into the engaged position. In preferred embodiments this completes the tamper circuit.

The cover 426 of the tag 410 is then pivoted into the closed position against the force of the torsion spring. Closing the cover 426 acts to engage the closure mechanism to prevent unauthorised opening of the cover 426 and actuates the cover switch to arm the alarm circuit. It will be appreciated, therefore, that closing the main body 412 of the tag 410 automatically arms the alarm circuit.

When the alarm circuit is activated, with the cover 426 of the tag 410 closed, movement of the trigger member 522 from the engaged position to the extended position preferably triggers the alarm. This will occur if, for example, the security tag 410 is lifted away from the surface of the object. In these circumstances, the force applied to the contact surface 526 of the trigger member 522 by the surface of the object is removed or reduced such that the biasing member causes the trigger member 522 to move towards the extended position. The circuitry is preferably configured such that when the trigger member 522 protrudes from the outer surface 431 of the base plate 430 by a predetermined distance the alarm is triggered and an audible sound is emitted. A person may then be alerted to the unauthorised removal of the security tag 410 from the object.

To allow the security tag 410 to be removed from the object without triggering the alarm the security tag 410 must be deactivated. This is preferably achieved by opening the cover 426 of the security tag 410 as described above in relation to the first embodiment of the security tag 10.

At a point of sale, or other convenient location, the security tag 410 may be quickly and easily detached from the object. Preferably, a suitable detacher, which as explained above may be a magnetic detacher, is applied to the security tag 410 to release the closure mechanism. The cover 426 is then urged into the open position by the housing biasing member (torsion spring). This in turn releases the pressure on the cover switch such that the power supply to the alarm circuit is disconnected. A user can then detach the main body 412 of the security tag 410 from the object, and movement of the trigger member 522 into the extended position will not trigger the alarm.

In preferred embodiments the main body 412 of the security tag 410 is reusable and may be attached to another object as described above. It will be appreciated, however, that the main body 412 may not be attached to a second object immediately after removal from a first object. It is therefore desirable to be able to store the main body 412 of one or more tags 410 before re-use. It will also be appreciated that it is preferable if the main body 412 of the tag 410 can be stored in the closed configuration to prevent damage to the contents of the tag 410; however, in preferred configurations of the tag 410, the alarm circuit is armed when the cover 426 is closed.

The circuitry therefore preferably comprises a master switch housed in the interior of the main body 412 of the tag 410. The master switch is preferably arranged to control power supply to at least a part of the circuitry, for example the alarm system. The master switch is preferably only accessible when the cover 426 is in the open position. In this way, the security tag 410 can be fully deactivated or switched off for storage or transportation such that an alarm cannot be triggered. The security tag 410 may therefore be stored in the closed configuration without the alarm system being activated by the cover switch. In preferred embodiments the master switch is in the form of a manual switch that is operable by a user when the cover 426 is in the open position.

It will be appreciated that in other embodiments the trigger member may be connected to the main body of the security tag in any suitable way to allow the trigger member to move between an extended position and a retracted position. The trigger member may, for example, be pivotally connected to a part of the main body.

It will further be appreciated that while, in the above embodiment, the trigger member was arranged such that when the trigger member moved to the extended position the tamper circuit was broken and the alarm was triggered, in other embodiments the trigger member may be arranged such the when the trigger member moves to the extended position the tamper circuit is completed and the alarm is triggered.

In yet further embodiments of the security tag, the tamper element may be of any suitable configuration that allows the tamper circuit to detect if the security tag has been moved away or separated from an object. The tamper element may comprise a light sensor or an infra-red sensor that detects whether the base of the main body of the security tag is in contact with a surface of an object. The circuitry may be arranged to trigger an alarm when the base of the main body is moved a pre determined distance away from a surface of the object.

It will be appreciated that in all of the embodiments described above the hinged connection between the base and the cover helps to align the parts of the closure mechanism. For example, because the cover is permanently secured to the base, in the second embodiment of the tag described above the pin is always correctly aligned with the clutch mechanism when the cover of the tag is closed. In this way, a user may conveniently secure the cover in the closed position without the need to align parts of the closure mechanism manually.

It will further be appreciated that other parts of the security tag will also remain correctly aligned. For example, in the first and second embodiments the clamping projection(s) will be aligned with the first and second conductive contacts, and the lug will be aligned with the push-button switch.

In further embodiments the base and the cover may remain connected together in the open configuration, but the base and the cover may be connected by means other than a hinge. The base and the cover may be slidingly connected such that the cover is slid between open and closed positions to access the interior of the main body.

In further embodiments, a security tag according to the invention may comprise an AM label or RF label, which is arranged to be permanently deactivated at the point of sale. In these embodiments, the security tag may be reused by replacing the AM label or RF label. Alternatively, the security tag may not be reusable.

In some embodiments, the cover switch may not be a push switch. For example, the cover switch may comprise complementary electrical contacts on the cover and base arranged to complete a circuit when the cover is closed. Alternatively, the cover switch may comprise a reed switch, and a magnet arranged to operate the reed switch may be disposed in the cover. In other embodiments the cover switch may comprise a microcontroller. In this case, the microcontroller may be connected to circuitry configured to detect an external signal from a deactivator, and the microcontroller may be configured to disarm the security tag in response to the external signal. For example, a deactivator may apply a magnetic field, or emit a radio frequency signal, an optical signal, or a microwave signal. The microcontroller may be configured to switch from a first state to a second state in response to the external signal. In this way the security tag may be disarmed independently from opening the cover. In practice, the tag may still be disarmed at the same time as opening the tag to allow detachment of the tamper element. For example, a suitable detacher may emit a signal to disarm the circuitry, whilst also applying a magnetic field to release the closure mechanism.

Other modifications and variations not explicitly disclosed above may also be contemplated without departing from the scope of the invention as defined in the appended claims.

Claims

1. A security tag for attachment to an object to deter theft of the object, the security tag comprising: a main body comprising a base and a cover, the cover being moveable relative to the base between an open configuration and a closed configuration, and the cover being connected to the base in both the open and closed configurations; a closure mechanism configured to retain the cover in the closed configuration; a housing biasing member configured to urge the cover into the open configuration on release of the closure mechanism; circuitry housed in an interior of the main body, the circuitry comprising a cover switch, an alarm and a master switch; and a tamper element forming part of a tamper circuit; wherein,

2. A security tag according to Claim 1 , wherein the tamper element comprises an elongate flexible element.

3. A security tag according to Claim 1 or Claim 2, wherein the tamper element comprises a tape or strap.

4. A security tag according to Claim 2 or Claim 3, wherein the tamper element comprises an adhesive layer for securing the tamper element to an object.

5. A security tag according to any one of Claims 2 to 4, wherein the tamper element comprises an elongate conductive element and the circuitry includes a pair of conductive contacts, the conductive element being electrically connectable to the conductive contacts to form the tamper circuit.

6. A security tag according to Claim 5, wherein the tamper element comprises an insulating backing layer.

7. A security tag according to Claim 5 or Claim 6, wherein the alarm is triggered when the tamper element is broken.

8. A security tag according to any one of Claims 5 to 7, further comprising a clamping mechanism arranged to apply a force to regions of a tamper element connected to the conductive contacts when the cover is in the closed configuration.

9. A security tag according to Claim 8, wherein the clamping mechanism comprises one or more projections arranged to contact the regions of a tamper element connected to the conductive contacts when the cover is in the closed configuration and to be separated from the regions of a tamper element connected to the conductive contacts when the cover is in the open configuration.

10. A security tag according to any preceding claim, wherein the circuitry is configured such that, when the cover is in the closed configuration, the alarm system is activated only if the tamper circuit is complete.

11. A security tag according to any one of Claims 5 to 9, wherein the master switch comprises at least one of the pair of conductive contacts.

12. A security tag according to any one of Claims 1 to 10, wherein the master switch comprises a manual switch housed in the main body and the manual switch is inaccessible when the cover is in the closed position.

13. A security tag according to Claim 1 , wherein the tamper element is configured to detect a loss of contact between the main body and an object to which the security tag is attached.

14. A security tag according to Claim 13, wherein the tamper element comprises a trigger member moveable between a first position and a second position.

15. A security tag according to any preceding claim, in which the base of the main body comprises an adhesive layer for attaching the main body to an object.

16. A security tag according to Claim 15, wherein the adhesive layer comprises a stretch release adhesive.

17. A security tag according to any preceding claim, in which the cover is connected to the base by a hinge.

18. A security tag according to Claim 17, in which the housing biasing member comprises a torsion spring.

19. A security tag according to any preceding claim, wherein the closure mechanism is biased into a locked configuration arranged to retain the cover in the closed configuration.

20. A security tag according to Claim 19, wherein the closure mechanism is releasable from the locked configuration using an external detacher.

21. A security tag according to Claim 20, wherein the closure mechanism comprises a pin and a ball clutch mechanism, and the pin is releasable from the ball clutch mechanism using an external magnetic detacher.

22. A security tag according to any preceding claim, wherein the cover switch comprises a non-latching switch.

23. A security tag according to Claim 22, wherein the cover switch is configured such that the cover switch is depressed when the cover is in the closed configuration and the cover switch is released when the cover is in the open configuration.

24. A security tag according to any preceding claim, further comprising an electronic article surveillance (EAS) sensor element.

25. A security tag according to Claim 24, wherein the EAS sensor element is electrically connected to the alarm.

26. A security tag according to any preceding claim, wherein the circuitry comprises a buzzer configured to sound when the alarm is triggered.

27. A method of attaching a security tag to an object to deter theft of said object, the security tag being according to any one of Claims 1 to 26, and the method comprising: attaching the main body of the security tag to the object with the cover in the open configuration; and moving the cover into the closed configuration to switch the cover switch to the first state and activate the alarm of the security tag.

28. A method according to Claim 27, the security tag being according to any one of Claims 1 to 26 when dependent on Claim 5, and the method comprising: attaching a first region of the tamper element to a first one of the conductive contacts; wrapping the tamper element around said object; and attaching a second region of the tamper element to a second one of the conductive contacts.

29. A method of removing a security tag from an object, the security tag being according to any of Claims 1 to 26, and the method comprising: applying a detacher to the main body of the security tag to release the closure mechanism such that the biasing member automatically urges the cover into the open configuration; and detaching the main body from the object.

30. A method according to Claim 29, the security tag being according to any one of Claims 1 to 26 when dependent on Claim 5, and the method comprising, after releasing the closure mechanism, disconnecting regions of the tamper element from the conductive contacts.