Patent Publication Number: US-2015061872-A1

Title: Security tag with an anti-defeat mechanism

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/870,415 filed Aug. 27, 2013, the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This document relates generally to security tags and associated detachers. More particularly, this document relates to a security tag and an associated detacher for used in an Electronic Article Surveillance (“EAS”) system. 
     BACKGROUND OF THE INVENTION 
     A typical EAS system in a retail setting may comprise a monitoring system and at least one security tag or label attached to an article to be protected from unauthorized removal. The monitoring system establishes a surveillance zone in which the presence of security tags and/or labels can be detected. The surveillance zone is usually established at an access point for the controlled area (e.g., adjacent to a retail store entrance and/or exit). If an article enters the surveillance zone with an active security tag and/or label, then an alarm may be triggered to indicate possible unauthorized removal thereof from the controlled area. In contrast, if an article is authorized for removal from the controlled area, then the security tag and/or label thereof can be deactivated and/or detached therefrom. Consequently, the article can be carried through the surveillance zone without being detected by the monitoring system and/or without triggering the alarm. 
     The security tags may be reusable, and thus include releasable attachment devices for affixing the security tags to the articles. Such attachment devices are further designed to be releasable by authorized personnel only so that unauthorized removal of the security tags from their articles can be avoided. To this end, many attachment devices are made releasable only through the use of an associated special hook or detaching mechanism. 
     An exemplary security tag employing an attachment device and an associated detacher is described in U.S. Pat. No. 3,942,829 (“the &#39;829 patent”), entitled REUSABLE SECURITY TAG and assigned to the same assignee hereof. The security tag of the &#39;829 patent includes a tag body and an attachment device in the form of a tack assembly. The tack assembly includes an enlarged head and a tack body having a pointed end. During use, the tack body pierces through an article and is clamped to the tag body. The clamping is achieved using a spring clamp formed as a clutch lock with spreadable jaws. Once the article is pierced, the pointed end of the tack body is secured between the jaws of the clutch lock. In effect, the tack body is locked inside the tag body such that the security tag cannot be removed from the article without use of a special detacher mechanism. The detacher mechanism is adapted to grip the tag body and apply a bending force thereto. This force is sufficient to deform the clutch so that the jaws of the clutch lock are spread apart, whereby the tack body can be removed from the tag body and decoupled from the article. 
     To permit bending of the tag body by a sufficient amount for deforming the clutch lock, the tag body must be made of a flexible material (e.g., plastic). Such flexible materials are susceptible to being cut and damaged. Moreover, the tag body must be relatively large in size in order to facilitate its flexing, which has an undesirable affect on the aesthetic appearance of the security device. 
     Another exemplary security tag is described in U.S. Pat. No. 5,031,756 (“the &#39;756 patent”), entitled KEEPER FOR COMPACT DISC PACKAGE OR THE LIKE and assigned to the assignee hereof. The keeper of the &#39;756 patent comprises a rigid plastic frame. One side of the frame is provided with an enlarged section which houses a tack-like button assembly and a spring clamp as in the &#39;829 patent. In this case, the spring clamp is used to lock the button assembly in a first position in which the pointed end of the button assembly protrudes into the frame so as to couple a cardboard container containing the compact disc thereto. As a result, unauthorized removal of the compact disc with the frame causes an EAS sensor incorporated into the frame to generate a signal detectable by an EAS system. 
     An enlarged section of the frame is provided with opposing linear slots leading to the region between the jaws of the spring clamp. The linear slots undesirably permit in-line viewing and access to the clamp. By inserting ramped linear fingers into the slots, the fingers are guided into the region between the spring clamp jaws thereby causing the jaws to flex away from each other. The ramped linear fingers are relatively expensive components of the security device because of high precision required therefore. When the jaws flex away from each other, the button assembly can be removed from the frame. Thereafter, the cardboard container and its housed compact disc can be separated from the frame. 
     Yet another exemplary security tag employing an attachment device and an associated detacher is described in U.S. Pat. No. 5,426,419 (“the &#39;419 patent”), entitled SECURITY TAG HAVING ARCUATE CHANNEL AND DETACHER APPARATUS FOR SAME and assigned to the same assignee hereof. The security tag of the &#39;419 patent includes a tag body and an attachment element or device in the form of a tack assembly. The tack assembly is used to attach the tag body to an article which is to be protected by the security tag. This is accomplished by inserting a tack into an opening in the tag body. When the tack is fully inserted into the opening, it is releasably secured in the tag body via a releasable locking means. Access to the releasable locking means is through an arcuate channel. With this configuration, a special arcuate probe is needed to reach and release the releasable locking means, and thus detach the security tag from the article. 
     SUMMARY OF THE INVENTION 
     The present invention concerns implementing systems and methods for selectively preventing an unauthorized detachment of a security tag from an article. The methods involve: coupling the security tag to the article by locking a tack assembly to a securement member disposed within a housing of the security tag; guiding an external tool into a channel formed within the security tag for releasing the tack assembly from the securement member; and inhibiting the external tool&#39;s movement of the securement member by biasing an obstruction member into a first position in which the obstruction member at least partially extends into a space formed between a clamp body of the securement member and a spring sleeve of the securement member. 
     The obstruction member may be biased into the first position using a resilient member disposed adjacent to the obstruction member within the housing of the security tag. In this case, a magnetic field is applied to the security tag so as to transition the obstruction member from the first position to a second position in which the external tool&#39;s movement of the securement member is no longer inhibited by the obstruction member. The magnetic field causes compression of a resilient member, whereby the obstruction member transitions from the first position to the second position. At this time, the securement member can be moved by the external tool so as to release the tack assembly from the securement member. Once the tack assembly has been released, the external tool can be withdrawn from the channel. Next, application of the magnetic field to the resilient member is terminated so as to cause the obstruction member to return to the first position. 
     Notably, the present invention is not limited to the above-described securement mechanism configuration. In other scenarios, the securement member alternatively or additionally comprises a solenoid switch with a detent that inhibits movement of the securement member until released. The detent is released when current is supplied to the solenoid switch. The current can be supplied to the solenoid switch when an authorized transaction is occurring or has occurred in relation to the article to which the security tag is coupled. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Embodiments will be described with reference to the following drawing figures, in which like numerals represent like items throughout the figures, and in which: 
         FIG. 1  is a perspective view of an exemplary security tag and detachment mechanism that is useful for understanding the present invention. 
         FIG. 2  is a cross sectional side view of the exemplary security tag shown in  FIG. 1 . 
         FIG. 3  is a perspective view of a securement mechanism of the security tag shown in  FIG. 1 . 
         FIG. 4  is a top perspective view of a bottom portion of the exemplary security tag shown in  FIG. 1  with the detachment mechanism inserted therein. 
         FIG. 5  is a top perspective view of a bottom portion of the exemplary security tag shown in  FIG. 1  with the detachment mechanism withdrawn therefrom. 
         FIG. 6  is a schematic illustration of an exemplary fish tape useful for defeating a security tag. 
         FIGS. 7-8  provide schematic illustrations that are useful for understanding operations of a barrier structure of the exemplary security tag shown in  FIG. 1 . 
         FIG. 9  is a top perspective view of an exemplary detacher that is useful for understanding the present invention. 
         FIG. 10  is a schematic illustration of an exemplary architecture for a detent solenoid switch that is useful for understanding the present invention. 
         FIG. 11  is a flow diagram of an exemplary method for preventing an unauthorized detachment of a security tag from an article. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It will be readily understood that the components of the embodiments as generally described herein and illustrated in the appended figures could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the figures, is not intended to limit the scope of the present disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated. 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by this detailed description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. 
     Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussions of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment. 
     Furthermore, the described features, advantages and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the invention can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. 
     Reference throughout this specification to “one embodiment”, “an embodiment”, or similar language means that a particular feature, structure, or characteristic described in connection with the indicated embodiment is included in at least one embodiment of the present invention. Thus, the phrases “in one embodiment”, “in an embodiment”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
     As used in this document, the singular form “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. As used in this document, the term “comprising” means “including, but not limited to”. 
     Embodiments of the present invention will now be described with respect to  FIGS. 1-10 . The present invention generally relates to novel systems and methods for reducing defeat of security tags using counterfeit hooks or detachment mechanisms. In this regard, anti-defeat structure is provided in an arcuate channel of a tag body so as to prevent counterfeit hooks from decoupling a security tag from an article without using an authorized detacher (or external tool). An exemplary embodiment of a conventional authorized detacher is provided in the &#39;419 patent, which is incorporated herein by reference. The detacher of the present invention is similar to that of the &#39;419 patent. In some scenarios, the detacher of the present invention may comprise some additional features (e.g., the addition of a magnet for controlling a position of the anti-defeat structure). The particularities of the novel anti-defeat structure and detacher will become more evident as the discussion progresses. 
     Notably, the security tags and detachers (or external tools) of the present invention can be used in a variety of applications. For example, the present invention can be used in an EAS system for detecting the unauthorized removal of articles from a particular area or space. EAS systems are well known in the art, and therefore will not be described herein. 
     Referring now to  FIGS. 1-5 , there is provided schematic illustrations useful for understanding an exemplary security tag  100  in accordance with the present invention. As shown in  FIGS. 1-5 , the security tag  100  includes a housing  104  with an upper housing member  106  joined to a lower housing member  108 . The upper housing member comprises sidewalls  122 - 128 , while the lower housing member  108  comprises sidewalls  130 - 138 . The housing members  106 ,  108  can be joined together via an adhesive, a mechanical coupling means (e.g., snaps, screws, etc.), or a weld (e.g., an ultrasonic weld). The housing  104  can be made from a rigid or semi-rigid material, such as plastic. The housing  104  has an opening  204  formed therein such that at least a portion of a tack assembly  110  (or attachment element) can be inserted into the security tag for facilitating the attachment of the security tag to an article  114  (e.g., a piece of clothing). EAS and/or Radio Frequency Identification (“RFID”) components are contained within the housing  104 . EAS and RFID components of security tags are well known in the art, and therefore will not be described herein. 
     Tack assembly  110  has a tack head  112  and an elongate tack body  202  extending down and away from the tack head. The tack body  202  is sized and shaped for insertion into opening  204  and removal from opening  204 . A plurality of grooves  406  may be formed along a length of the tack body  202  for engagement with a securement mechanism  206  disposed within the housing  104 . When the grooves  406  are engaged by the securement mechanism  206 , the security tag  100  is secured to the article  114 . Thereafter, unauthorized removal of the article  114  from a controlled area can be detected by a monitoring device of an EAS system. Such monitoring devices are well known in the art, and therefore will not be described herein. Still, it should be understood that at least one sensor  206  is disposed within the housing  104 . The sensor includes, but is not limited to, an acoustically resonant magnetic sensor. In all cases, the sensor generates signals which can be detected by the monitoring device. 
     Such detection occurs when the security tag is present within a surveillance zone established by the monitoring device. The surveillance zone is usually established at an access point for the controlled area (e.g., adjacent to a retail store entrance and/or exit). If the article  114  enters the surveillance zone with the security tag  100 , then an alarm may be triggered to indicate possible unauthorized removal thereof from the controlled area. In contrast, if the article  114  is authorized for removal from the controlled area, then the security tag  100  thereof can be deactivated and/or detached therefrom using a detachment mechanism  102  (or external tool). Consequently, the article  114  can be carried through the surveillance zone without being detected by the monitoring system and/or without triggering the alarm. 
     The detachment mechanism  102  is sized and shaped to at least be partially slidingly inserted into and removed from an insert space  116  formed in the housing  104 . When inserted into insert space  116 , the detachment mechanism  102  travels through an arcuate channel  500  so as to be guided towards the securement mechanism  206 . In this regard, the detachment mechanism  102  has a generally arcuate shape matching that of the arcuate channel  500 . Upon engagement with the securement mechanism  206 , the detachment mechanism  102  releases the tack body  202  therefrom. Next, the tack body  202  can be removed from the housing, so as to decouple the security tag  100  from the article  114 . 
     A schematic illustration of the securement mechanism  206  is provided in  FIG. 3 . As noted above, the securement mechanism  206  is specifically adapted to accommodate release of the tack body  202  via the detachment mechanism  102  (or arcuate probe) moving in the arcuate channel  500 . The securement mechanism  206  is generally in the form of a spring clamp securely disposed with the housing  104  of the security tag so as to be pivotable (or rotatable) about an axis  208 . In this regard, the spring clamp comprises a clamp body  302  and jaws  304 ,  306 . The clamp body  302  includes a mounting part  308  extending laterally of jaw  306  and a release part  310  extending laterally of jaw  304 . The mounting part  308  includes a mounting aperture  312  facilitating the pivotable movement of the securement mechanism  206  within the housing of the security tag. The pivotable movement allows the securement mechanism  206  to be transitioned by the detachment mechanism  102  (or arcuate probe) from a first position in which the tack assembly is locked thereto and a second position in which the tack assembly is released or unlocked therefrom. 
     Each of the jaws  304 ,  306  extends outwardly of the plane of the clamp body  302  and then inwardly toward the other jaw. The jaws  304 ,  306  terminate in facing edges  314 ,  316 . These edges extend from a common edge  318  of the clamp body  302  inwardly toward each other, then curve outwardly away from each other to define an aperture  320  (typically, circular or elliptical) for receiving the tack body  202 . The edges  314 ,  316  then continue in aligned fashion and end in an elongated, lateral slot  322  in the clamp body  302 . The lateral slot lies inward of a further clamp body edge  324  which opposed the clamp body edge  318 . 
     A further laterally extending elongated spring sleeve  326  is attached by a joint area  328  to the side  330  of the edge  324  bordering the mounting part  308 . The sleeve  326  extends along the length of the edge  324  and is also out of the plane of the clamp body  302 . 
     For mounting and supporting the spring clamp  302 , the lower housing member  108  of the security tag  100  includes a circular mount  402 . The spring clamp  302  is mounted, via aperture  312  of the mounting part  308 , on the circular mount  402 . In this way, the mounting part  308  can be rotated about the circular mount  402 . The spring clamp  302  is thus able to pivot about the mounting part  308  as will be described more fully below. 
     When an end  404  of the tack assembly  110  is introduced in the downward direction through the opening  204  in the upper housing member  106 , the tack body  204  is directed to aperture  320  of the securement mechanism  206 . This causes the jaws  304 ,  306  to spread open and allow the tack body  204  to pass there through. 
     When the downward movement of the tack assembly  110  is stopped, the jaws  304 ,  306  retract and clutch the tack body  204 . In this position, the jaws  304 ,  306  prevent upward movement of the tack assembly  110 . As such, the security tag  100  becomes securely coupled to the article  114 . 
     In order to release the tack body  204  from the jaws  304 - 306 , the detachment mechanism  102  is introduced into the insert space  116  formed in the housing  104  of the security tag  100 . Rotation of the detachment mechanism  102  causes it to be moved in and guided by the arcuate channel  500  until the end  118  abuts portion  332  of the securement mechanism  206 . Continued rotational movement of the detachment mechanism  102  causes force to be applied to portion  332  of the securement mechanism  206 . This force, in turn, causes the clamp body  302  to rotate about the support area  308 . The jaw  304  is thus enabled to spread away from jaw  306  due to the force of the tack body  204 , which is being held stationary by jaw  306 . As a result, aperture  320  expands, releasing the tack body  204  from the clutch of the jaws. The tack assembly  110  can now be moved in the upward direction past the jaws, via an upward force on the tack head  112 . 
     During rotation of the clamp body  302 , the spring sleeve  326  at the joint area  328  is compressed. After the tack assembly  110  is separated from the housing  104 , the detachment mechanism  102  is rotated in the reverse direction. This reverse rotation disengages the detachment mechanism  102  from the securement mechanism  206 . Consequently, the spring sleeve  326  rotates in an opposite direction so as to be brought back to its original position. Thereafter, the detachment mechanism  102  is guided out of the arcuate channel  500  and is removed from insert space  116  formed in the housing  104 . 
     Notably, the security tag  100  is adapted so that access to securement mechanism  206  for releasing tack assembly  110  is made difficult for other than authorized personnel. However, defeats have occurred by using a bent piece of common electrical fish tape to unlock the mechanical clutch. Fish tape is a relatively rigid but bendable steel wire used to pull electrical wires through conduits. 
     A schematic illustration of an exemplary segment  600  of fish tape is provided in  FIG. 6 . Segment  600  is formed to resemble the detachment mechanism  102  (or arcuate probe). The fish tape is available in a variety of sizes, and has a rectangular cross sectional profile  602 . The cross sectional profile  602  simulates the shape of a portion  140  of an end  118  of the detachment mechanism  102 . 
     In a defeat attempt, the formed fish tape  600  is inserted into arcuate channel  500  until it can be manipulated into and against securement mechanism  206 , which then can be rotated to release tack assembly  110  as described above. The formed fish tape  600  is strong enough to hold its form when pushed into arcuate channel  500  to engage securement mechanism  206  to release tack assembly  110 . The solution to prevent such defeats, as fully described below, is to modify the security tag  100  to make it impossible to actuate the securement mechanism  206  using a formed fish tape or other rigid/semi-flexible wire for releasing tack assembly  110 . 
     Notably, a barrier structure  502  is provided within the housing  104  for preventing counterfeit hooks from actuating the securement mechanism  206  without using an authorized detacher. As shown in  FIGS. 7-8 , the barrier structure  502  comprises an obstruction member  702  disposed in a channel  706  formed in the lower housing member  108 . In a first position shown in  FIGS. 5 and 7 , the obstruction member  702  at least partially extends out and away from the channel  706 . Within the channel  706  and beneath the obstruction member  702  resides a spring  704 . The obstruction member  702  and spring  704  are movable within channel  706  in an upward direction  708  and a downward direction  710 . The obstruction member  702  can be made from a variety of materials, including ferrous and non-ferrous materials. 
     The spring  704  is normally biased to press upon a bottom surface  702  of the obstruction member  702 , thereby forcing the obstruction member  702  into its first position. While the obstruction member  702  is in its first or engaged position, the obstruction member  702  obstructs rotation of the clamp body  302  by a probe applying three on portion  332  of the securement mechanism  206 . In this regard, the obstruction member  702  extends into a space  350  formed between the clamp body  302  and the spring sleeve  326  of the securement mechanism  206  such that the jaws  304 ,  306  cannot be spread apart as a result of applying force upon the clamp body  302 . Stated differently, the barrier structure  502  inhibits movement of the securement mechanism  206  by an external tool. As such, mere insertion of a detachment mechanism  102  into the arcuate channel  500  will not result in the rotation of the securement mechanism  206  so as to release the tack body  204  from the clutch of the jaws  304 ,  306 . 
     When the security tag  100  is brought to a Point Of Sale (“POS”) station of an EAS system, the obstruction member  702  can be retracted into the channel  706  using an authorized detacher, thus transitioning from its first position shown in  FIGS. 5 and 7  into its second or unengaged position shown in  FIGS. 4 and 8 . PUS stations and EAS systems are well known in the art, and therefore will not be described herein. In some scenarios, the obstruction member  702  is transitioned to its second position by placing a magnet therebelow so as to cause compression of the spring  704 . While the obstruction member  702  is in its second position, the detachment mechanism  102  can access the securement mechanism  206 , as described above, for releasing the tack body  204  from the clutch of the jaws  304 ,  306 . In effect, the security tag  100  can be safely removed from its article  114 . 
     Referring now to  FIG. 9 , there is provided a schematic illustration that is useful for understanding operations of an authorized detacher  900  for detaching a security tag  100  from an article  114 . More particularly,  FIG. 9  is a top perspective view of an exemplary detacher  900 . The detacher  900  incorporates the arcuate detachment mechanism  102 . The detacher  900  is a manual actuated assembly and/or a power actuated assembly for detaching a security tag  100  from an article  114 . Manual actuated assemblies are well known in the art, and therefore will not be described herein. In some power actuated assemblies, the detacher  900  comprises an electronic circuit that is supplied power from an external power source and/or an internal power source (e.g., a battery). The electronic circuit and/or internal power source are contained within a housing  902 . An exposed ON/OFF switch (not shown) is provided for turning the detacher  900  on and off. At least one indicator  906  (e.g., a light emitting diode) is provided for indicating an on/off status of the detacher  900 . 
     The housing  902  includes a nesting or cradle area  904  for receiving the security tag  100 . When the security tag  100  is inserted into the cradle area  904 , a magnet  908  of the detacher  900  actuates the spring  704  of the barrier structure  502 . In turn, the spring  704  compresses thereby causing the obstruction member  702  to be transitioned from its first position shown in  FIGS. 5 and 7  to its second position shown in  FIGS. 4 and 8 . 
     Thereafter, in the manual and/or power actuated scenarios, the detacher  900  performs electrical and/or mechanical operations for rotating the detachment mechanism  102  in a counter clockwise direction. Electrical and mechanical means for causing rotation of the detachment mechanism  102  are well known in the art, and therefore will not be described in detail herein. Still, it should be understood that in some power actuated scenarios, the detacher  900  comprises at least one switch (not shown). This switch provides signals over lines (not shown) to control the electronic circuit internal to the housing  902 , which may be mounted on a printed circuit board (not shown). The electrical circuit, in turn, provides drive signals to a drive motor (not shown) for driving the same so as to realize movement of the detachment mechanism  102 . 
     As a result of said rotation, the detachment mechanism  102  is introduced into the insert space  116  formed in the housing  104  of the security tag  100 . Rotation of the detachment mechanism  102  causes it to be moved in and guided by the arcuate channel  500  until the end  118  abuts portion  332  of the securement mechanism  206 . Continued rotational movement of the detachment mechanism  102  causes force to be applied to portion  332  of the securement mechanism  206 . This force, in turn, causes the clamp body  302  to rotate about the support area  308 . The jaw  304  is thus enabled to spread away from jaw  306  due to the force of the tack body  204 , which is being held stationary by jaw  306 . As a result, aperture  320  expands, releasing the tack body  204  from the clutch of the jaws. The tack assembly  110  can now be moved in the upward direction past the jaws, via an upward force on the tack head  112 . 
     After the tack assembly  110  is separated from the housing  104 , the detachment mechanism  102  is rotated in the reverse direction. This reverse rotation disengages the detachment mechanism  102  from the securement mechanism  206 . Consequently, the spring sleeve  326  rotates in an opposite direction so as to be brought back to its original position. Thereafter, the detachment mechanism  102  is guided out of the arcuate channel  500  and is removed from insert space  116  formed in the housing  104 . 
     When the security tag  100  is removed from the cradle area  904  of the manual or power actuated detacher  900 , the magnetic field applied to the spring  704  of the barrier structure  502  is removed therefrom. Consequently, the obstruction member  702  returns to its first position in which it obstructs movement of the securement mechanism  206  via a probe inserted into the arcuate channel  500 . 
     Notably, the present invention is not limited to the mechanical-magnetic based architecture for the securement member  206 . Other mechanical, electrical, electromechanical, and/or electromagnetic architectures can be employed to achieve the same result described above (i.e., inhibit an external tool&#39;s movement of the securement member). For example, in an electromagnetic scenario, the securement member architecture described above can be replaced with or used in conjunction with a detent solenoid switch  1000 , as shown in  FIG. 10 . The detent solenoid switch comprises a detent (i.e., a catch or hook) that prevents motion of the securement mechanism until released. Detent solenoid switches are well known in the art, and therefore will not be described herein. Still, it should be understood that the detent solenoid switch operates when electric current is passed therethrough. As such, the detacher would need to communicate a signal to the security tag including information for causing said electric current to be passed through the solenoid switch at certain times (e.g., when an authorized transaction is deemed to be occurring or has occurred regarding the article to which the security tag is coupled). The electric current can be supplied by a power source  1002  (e.g., a battery) disposed in the housing of the security tag. 
       FIG. 11  is a flow diagram of an exemplary method  1100  for preventing an unauthorized detachment of a security tag (e.g., security tag  100  of  FIG. 1 ) from an article (e.g., article  114  of  FIG. 1 ). The method  1100  begins with step  1102  and continues with step  1104 . In step  1104 , the security tag is coupled to the article by locking a tack assembly (e.g., tack assembly  110  of  FIG. 1 ) to a securement member (e.g., securement member  206  of  FIG. 2 ) disposed within a housing (e.g., housing  104  of  FIG. 1 ) of the security tag. Next in step  1106 , an external tool (e.g., tool  102  of  FIG. 1 ) is guided into a channel (e.g., channel  500  of  FIG. 5 ) formed within the security tag for releasing the tack assembly from the securement member. Notably in step  1108 , the external tool&#39;s movement of the securement member is inhibited. This movement inhibition is achieved by biasing an obstruction member (e.g., obstruction member  702  of  FIG. 7 ) into a first position in which the obstruction member at least partially extends into a space formed between a clamp body (e.g., clamp body  302  of  FIG. 3 ) and a spring sleeve (e.g., spring sleeve  326  of  FIG. 3 ) such that jaws (e.g., jaws  304 ,  306  of  FIG. 3 ) cannot be spread apart as a result of applying force upon the clamp body. The obstruction member t can be biased into the first position using a resilient member (e.g., spring  704  of  FIG. 7 ) disposed adjacent to the obstruction member within the housing of the security tag. 
     At some time later, a magnetic field is applied to the security tag, as shown by step  1110 . As a result, the obstruction member transitions from the first position to a second position in which the external tool&#39;s movement thereof is inhibited by the obstruction member. In some scenarios, the magnetic field causes compression of a resilient member disposed within the housing of the security tag adjacent to the obstruction member. Compression of the resilient member, in turn, causes the post to transition from the first position to the second position. 
     Once the resilient member transitions into its second position, the securement member can be moved by the external tool so as to release the tack assembly therefrom, as shown by step  1112 . In some scenarios, the securement member is rotatably moved by the external tool so as to release the tack assembly from a clamp of the securement member. Subsequently, the external tool is withdrawn from the channel, as shown by step  1114 . In a next step  1116 , method  1100  ends or other steps is performed. 
     All of the apparatus, methods, and algorithms disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the invention has been described in terms of preferred embodiments, it will be apparent to those having ordinary skill in the art that variations may be applied to the apparatus, methods and sequence of steps of the method without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain components may be added to, combined with, or substituted for the components described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those having ordinary skill in the art are deemed to be within the spirit, scope and concept of the invention as defined. 
     The features and functions disclosed above, as well as alternatives, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements may be made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.