Detacher

This invention relates to a detacher for an electronic article surveillance (EAS) system. In particular it relates to a magnetic detacher for such a system.

EAS systems are used in the retail industry to deter and detect theft of stock. EAS systems typically comprise a security tag which is attached to a stock item and which can be detected by a detection system located at an exit of a store. , If a security tag is taken out of the store past the detection system an alarm sounds to alert store personnel to the unauthorized removal of the stock item. Conventional security tags are typically either single-use deactivatable tags or reusable tags. The reusable tags, also known as "hard" tags, are removed from the stock when the purchase is complete and are reused by being attached to further stock items.

Reusable tags are attached to stock items by a number of methods. "Safers" or "keepers" are lockable containers in which stock items are placed, and pin-connected tags are used to secure garments and accessories. Both the tags and the safers comprise a radio frequency, electromagnetic or acousto-magnetic EAS device which is detected by a detection system. Some tags and safers, such as those produced by Checkpoint Systems, Inc., Alpha Security Products, Inc: and WG Security Products, Inc., have pins and locks which are magnetically released from the pin-connected tags and the safers respectively by applying a magnetic field of specific magnitude at a specific position on the tag or safer.

Each tag and safer (from hereon to be known collectively as tags) is released by a dedicated detacher. As there are a number of different tags on the market, a retail store using two or more different tags requires a plurality of detachers. Maintaining a number of detachers is cumbersome for retail stores. Each detacher must be stored at the point of sale where space is at a premium. Each detacher and associated tag has its own method of operation, and checkout staff must be trained how to use each detacher.

As tags are effectively keys which can be used to allow removal of stock items, access to detachers should be restricted so that the detachers are accessible only to authorised personnel. If a detacher falls into the hands of an unscrupulous member of the public then the detacher may be used unlawfully to remove a tag from a stock item or remove a stock item from a safer, thus circumventing the security device. Hence, detachers are commonly secured at the point of sale to prevent unauthorised removal, either by rigid attachment to the point of sale or by anchoring the detacher by means of a belt or lanyard. Some detachers, in particular those which are rigidly attached to the- point of sale, have a removal lock which is locked into place to disable the device, thereby preventing unauthorised use. For these detachers the lock should be stored in a secure location once removed so as not to be lost or stolen.

Attaching a plurality of detachers rigidly to the point of sale clutters the point of sale and can be unsightly. Attaching a plurality of detachers to the point of sale by means of a belt or lanyard can lead to entanglement of the detachers which can lead to a delay in completing the purchase of the secured stock items.

If a plurality of detachers are used and if a detacher is lost or unlawfully removed then the absence of the detacher may not be immediately detected.

It is an object of this invention to overcome or ameliorate one or more of the problems of the prior art.

According to a first aspect of the invention there is provided a electronic article surveillance system detacher comprising: detaching means; and a cover pivotally mounted to move from a first position in which the detaching means is enabled to a second position in which the detaching means is disabled.

The detaching means may be disposed in a housing and the cover may be pivotally mounted on the housing.

The cover in the second position may at least partially cover the detaching means.

The detacher may further comprise one or more mounting holes for mounting the detacher on a surface, wherein the or at least one of the mounting holes is inaccessible when the cover is in the second position.

The detacher may further comprise a lock on one of the housing and the cover and a lock receiving portion for receiving the lock on the other of the housing and the cover. The or at least one of the mounting holes may be disposed in the lock receiving portion.

The detaching means may comprises one or more magnets or the detaching means may be mechanical.

The cover may be mounted on the housing by means of a hinge.

The housing may comprise a stepped portion at its underside adapted to be recessed into a counter.

The detacher may be arranged to release a plurality of different models of tags and/or safers, for example the tags and safers listed in Table 1 and Table 2.

According to a second aspect of the invention there is provided a magnetic detacher comprising a plurality of magnets, the detacher being arranged to release a plurality of ^■ different models of tags and/or safers.

The detacher may comprise two magnet arrangements, the first and second magnet arrangements having a substantially rectangular accessible surface.

The dimension ^' s of the accessible surface of the first magnet arrangement may be between 30mm by 20mm and 50mm by 40mm, preferably between 35mm by 25mm and 45mm by 35mm and further preferably between 39mm by 29mm and 41mm by 31mm.

The dimensions of the accessible surface of the second magnet arrangement may be between 15mm by 20mm and 25mm by 40mm, preferably between 17mm by 25mm

and 23mm by 35mm and further preferably between 19mm by 29mm and 21mm by 31mm.

The first magnet arrangement may be spaced from the second magnet arrangement by between 20mm and 30mm, preferably between 23mm and 27mm and further preferably by 25mm.

The dimensions of the accessible surface of the first magnet arrangement may be between 30mm by 10mm and 40mm by 20mm, preferably between 32mm by 12mm and 38mm by 18mm and further preferably between 34mm by 14mm and 36mm by 16mm.

The dimensions of the accessible surface of the second magnet arrangement may be between 40mm by 25mm and 60mm by 35mm, preferably between 45mm by 27mm and 55mm by 33mm and further preferably between 49mm by 29mm and 51mm by 3 lmm. The first magnet arrangement may be adjacent the second magnet arrangement.

Each of the first and second magnet arrangements may have opposed poles on their accessible surface, wherein diagonally opposed poles have the same polarity and adjacent poles have opposite polarity.

One or each of the first and second magnet arrangements may be comprised of two single-pole magnets or of a single dual-pole magnet. The first and second magnet arrangements may be comprised of a single four-pole magnet.

The detacher may be arranged to release the tags and safers listed in Table 1.

The magnetic detacher may further comprise a third magnet arrangement.

The third magnet arrangement may comprise an annular magnet towards the upper surface of the detacher and a discoidal magnet below the annular magnet.

The annular magnet may have an outer diameter of between 35mm and 45mm, preferably between 37mm and 43mm, and more preferably between 39mm and 41mm. The annular magnet may have an inner diameter of between 18mm and 28mm, preferably between 20mm and 26mm, and more preferably between 22mm and 24mm.

The discoidal magnet may have a diameter of between 20mm and 30mm, preferably between 22mm and 28mm, and more preferably between 24mm and 26mm.

The annular magnet and discoidal magnet may be orientated so that the abutting faces of the two magnets are of the same polarity.

The detacher may be arranged to release the tags and safers listed in Table 2.

The magnets may be made of a neodymium magnet of grade at least N30, preferably of grade at least N40 and further preferably of grade N45M.

The invention will described in more detail by way of example with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a detacher according to a first embodiment of the invention;

Figure 2 is a plan view of the detacher of Figure 1 in an open position;

Figure 3 is a side view of the detacher of Figure 1 in an open position;

Figure 4 is a side of a detacher according to a second embodiment of the invention in a closed position;

Figure 5 is a side view of the detacher of Figure 4 in an open position;

Figure 6 is a plan view of a detacher according to a third embodiment of the invention;

Figure 7 is a plan view of a detacher according to a fourth embodiment of the invention in an open position; and

Figure 8 is a side view of the detacher of Figure 7 in an open position.

Figure 1 is a perspective view of a detacher Ia according to a first embodiment of the invention. The detacher Ia is comprised of a housing 3 and a cover 5. The cover 5 is pivotally mounted on the housing 3 by means of a hinge 7 towards one end 9 of the detacher Ia. A lower end portion 11 of the housing 3 protrudes from the housing 3 at the end 9 of the detacher Ia where the hinge 7 is located. A mounting hole 13 is disposed in the protruding portion I L for receiving a screw (not shown) or other mounting means to mount the detacher on a shop counter etc. A lock 15 is mounted in a hole in the cover 5.

Figure 2 shows the detacher Ia of Figure 1 in an open position. Three magnet arrangements 21, 22, 23 are disposed in recesses 24, 25, 26 in the upper surface 17 of the housing 3. The upper surface of the first and second magnet arrangements 21, 22 is flush with the upper surface 17 of the housing 3. The third magnet arrangement 23 is substantially cup-shaped, a cavity 35 in the third magnet arrangement 23 being open to the upper surface 17 of the housing 3.

The first magnet arrangement 21 is rectangular in plan and is disposed at the end 9 of the detacher Ia proximal to the hinge 7. The second magnet arrangement 22 is rectangular in plan and is disposed towards the centre of the upper surface 17 of the housing 3. A groove 27 runs between the first magnet arrangement 21 and the second magnet arrangement 22 in the upper surface 17 of the housing 3. The third magnet arrangement 23 is disposed towards the end of the housing 3 distal to the hinge 7. A recess/lock receiving portion 29 for receiving the lock 15 is disposed in the upper surface 17 of the housing 3 between the second magnet arrangement 22 and the third magnet arrangement 23.

Each of the first magnet arrangement 21 and the second magnet arrangement 22 is comprised of two single-pole magnets 21a, 21b and 22a, 22b, each magnet 21a, 21b,

22a, 22b, running lengthways of the detacher Ia. The magnets 21a, 21b, 22a, 22b are arranged so that diagonally opposed magnets 21a, 22b and 2Ib ₅ 22a have the same polarity at their upper surface and adjacent magnets 21a, 21b, 22b, 22a have opposite polarity at their upper surface. The dimensions of an upper accessible surface of the first magnet arrangement 21 is 40mm x 30mm and the dimension of the second magnet arrangement 22 are 20mm x 30mm. The depth of each of the first magnet arrangement 21 and the second magnet arrangement 22 is 12.5mm. The distance between the first magnet arrangement 21 and the second magnet arrangement 22 is 25mm. The depth of the groove 27 between the first magnet arrangement 21 and the second magnet arrangement 22 is 3mm.

Figure 3 is a side view of the detacher Ia of Figure 1 in an open position. The third magnet arrangement 23 is comprised of an annular magnet 23a towards the upper surface 17 of the housing 3 and a discoidal magnet 23b below the annular magnet 23a. The annular magnet 23a and discoidal magnet 23b are orientated so that the abutting faces of the two magnets 23a, 23b are of the same polarity. The annular magnet 23a has an outer diameter of 40mm, an inner diameter of 23mm and a depth of 7mm and the discoidal magnet 23b has a diameter of 25mm and a depth of 15mm. The third magnet arrangement 23 is spaced 25mm away from the second magnet arrangement 22.

In addition to the first mounting hole 13 at the end 9 of the detacher Ia where the hinge 7 is located, there is a second mounting hole 14 towards the other end of the housing 3. The second mounting hole 14 is located at the bottom of the lock receiving portion 29 so that the hole formed by the lock receiving portion 29 and the second mounting hole 14 extends from the upper surface 17 of the housing 3 to the lower surface 18 of the housing 3. The second mounting hole 14 receives a screw (not shown) or other mounting means in a similar manner to the first mounting hole 13.

Towards the top of the lock receiving portion 29 but below the upper surface 17 of the housing 7 there is a notch 31 recessed into the housing 3 for receiving a tongue (not shown) of the lock 15.

The housing 3 and cover 5 are made of metal, but other materials can be used.

The detacher Ia is locked by closing the cover 5 onto the upper surface 17 of the housing 3 and by operating the lock 15 with a key 16 so that the tongue of the lock 15 enters the notch 31 in the lock receiving portion 29. When the cover 5 is closed the magnet arrangements 21, 22, 23 are covered and are consequently disabled. Also, when the cover 5 is closed, the mounting hole 14 is inaccessible and hence when the detacher Ia is closed the mounting means is inaccessible and the detacher Ia cannot be removed from the surface to which it is attached.

The detacher Ia is opened by operating the lock 15 with the key 16 so that the tongue of the lock 15 is withdrawn from the notch 31 and the cover 5 is opened so that the magnet arrangements 21, 22, 23 are accessible. Part of the open cover 5 rests on the upper surface 33 of the protruding portion 11 of the housing 3. When the cover 5 is open the magnet arrangements 21, 22, 23 are accessible and hence enabled.

The pivotally mounted cover 5 is an effective way of disabling the detaching means 21, 22, 23. As the cover 5 is fixed to the housing 3 and cannot be removed when the detacher Ia is open, the security of the detacher Ia is not compromised by potential removal of the detacher-disabling cover 5. As the cover 5 cannot be removed it cannot be misplaced. The detacher Ia is compact and discrete, which is desirable for a device used at a point of sale.

In use, the detacher Ia is opened to allow tags and safers to be brought into contact with the enabled magnet arrangements 21, 22, 23 to release the tags and safers. The groove 27 between the first magnet arrangement 21 and the second magnet arrangement 22 is used to accommodate certain safers.

Figures 4 and 5 show a detacher Ib according to a second embodiment of the invention. The cover 5 and the upper surface 17 of the housing 3 are identical to those parts in the first embodiment of Figures 1 to 3. A lower portion 41 towards the underside of the housing 3 is stepped so that lower portion 41 can be recessed into a counter 39, for example at a point of sale. There are two mounting holes 13, 14 in the lower surface 18 of the housing 3 to allow the detacher Ib to be attached to a counter 39 from below.

Unlike the housing 3 of the detacher Ia of the first embodiment, the housing 3 of the detacher Ib of the second embodiment does not have a protruding portion at the end 9 of the detacher Ib. As can be seen in Figure 5, when the cover 5 is in an open position it rests on the surface 37 of the counter 39. As the housing 3 of the detacher Ib can be partially recessed into the counter 39, it has a lower profile both when open and when closed and hence provides a more inconspicuous detacher.

Figure 6 shows a detacher Ic according to a third embodiment of the invention. The detacher Ic is similar in structure to the detacher Ia of Figures 1 to 3, the only difference being that the detacher only comprises a first magnet arrangement 21 and a second magnet arrangement 22 and does not comprise the third magnet arrangement 23 of the detacher Ia. This detacher Ic provides a more compact design than the detacher Ia of Figures 1 to 3.

Figures 7 and 8 show a detacher Id according to a fourth embodiment of the invention. The detacher Id is similar in structure to the detacher Ia of Figures 1 to 3, the detacher Id comprising different first and second magnet arrangements 71, 72.

Each of the first magnet arrangement 71 and the second magnet arrangement 72 is rectangular in plan view and is comprised of two magnets 71a, 71b and 72a, 72b in a similar orientation and polarity to the magnets 21a, 21b, 22a, 22b of Figures 1 to 3. The first magnet arrangement 71 is placed next to the second magnet arrangement 72 and opposed faces of the magnet arrangements 71, 72 are bevelled at angle of 45° to form a V-shaped cut-out between the magnet arrangements 71, 72, as shown in Figure 8. A tab 73 projects from the inclined surface 74 of the first magnet arrangement 71 towards the bottom of the V-shaped cut-out, partially across the width of the inclined surface 74. The tab assists release of some safers marketed under the Redtag brand name.

The dimensions of the first magnet arrangement 71 in plan view are 35mm x 15mm and the dimension of the second magnet arrangement 72 in plan view are 50mm x 30mm. The depth of each of the first magnet arrangement 71 and the second magnet arrangement 72 is 12.5mm.

The housing 3 of the detacher Id of Figures 7 and 8 can be adapted to have a form similar to the detachers Ib and Ic of Figures 4 to 6, i.e. so that the detacher can be recessed or with the third magnet arrangement 23.

The magnet arrangements 21, 22, 23, 71, 72 of the above embodiments are made from a neodymium magnet of grade N45M having properties: remnance (Br) 1.32-1.38 Tesla; intrinsic coercivity (H ₀ ) 1114 kA/m; and maximum energy product (BH _max ) 334-366 kJ/m ³ .

The detachers la-d are compact in nature so that they do not clutter a point of sale and can be secured in a closed position so that the detaching means is inaccessible and consequently disabled. Furthermore, as the cover 5 is attached to the housing 3 by a hinge, there is no risk that the cover 5 will be lost.

As a result of extensive research and experimentation, a design of the detachers la-d and more specifically the magnet arrangements 21, 22, 23, 71, 72 has been developed so that the detachers la-d detach a number of commonly available tags and unlock a number of commonly available safers, the detachers la-d thereby acting as "universal" detachers. In addition to each magnet arrangement 21, 22, 23, 71, 72 operating a tag/safer, the first magnet arrangement 21, 71 and the second magnet arrangement 22, 72 in combination unlock a number of commonly available safers. Tags and safers that can be detached/unlocked by one or more of the detachers la-d are shown in Tables 1 and 2.

Table 1 — Tags and safers that can he detached/unlocked using one or both of the rectangular magnet arrangements 21, 22, 71, 72 of detachers la-d

Table 2 — Tags and safers that can be detached/unlocked using the circular magnet arrangement 23 of detachers Ia, Ib and Id

In alternative embodiments one or more of the first magnet arrangements 21, 71 and the second magnet arrangements 22, 72 are comprised of a single magnet having opposite poles on the upper surface, each pole running lengthways of the detacher, with like poles of the first magnet arrangement 21, 71 and the second magnet arrangement 22, 72 diagonally opposed. Alternatively, the first magnet arrangement 71 and the second

λ2 magnet arrangement 72 of Figures 7 and 8 can be made from a single magnet having four poles in its upper surface.

The magnet arrangements 21, 22, 23, 71, 72 can be made of other neodymium magnets, for example those graded between N30 and the highest currently available grade of N53, or any other higher grade that will be available in the future.

For the detacher 1 shown in of Figures 1 to 6, the minimum dimensions of an upper accessible surface of the first magnet arrangement 21 is about 30mm x 20mm and the minimum dimension of the second magnet arrangement 22 is about 20mm x 20mm. The distance between the first magnet arrangement 21 and the second magnet arrangement 22 can be between 20mm and 30mm.

Various modifications will be apparent to those skilled in the art and it is desired to include all such modifications that fall within the scope of the accompanying claims.

For example, rather than the detaching means being magnetic, the detaching means may be mechanical, such as used in the AMD-3040 Hand-held Detacher and the AMD-3050 Power Detacher marketed by Sensormatic Electronics Corporation for detaching their SuperTag (RTM) tags. The cover 5 would block access to the mechanical detaching means and hence disable the detacher when closed and enable the detacher when the cover 5 is open.

The cover 5 may only partially cover the detaching means, for example only part of the magnets, sufficient to prevent the detaching means from detaching a tag or unlocking a safer, so that the detaching means is nevertheless disabled when not completely covered.

The number and position of magnets may be varied. A different lock 15 may be used. The lock 15 may be on the housing 3 and the lock receiving portion 29 may be on the cover 5. Further mounting holes 13, 14 may be provided.