n/a
The present invention relates to security tags, and in particular to security tags having magnetically releasable locks.
Electronic article surveillance (EAS) systems are rapidly becoming common place in a vast majority of businesses where removal of items needs to be monitored. Typical EAS systems include an EAS monitoring system and one or more security tags attached to various items that are detected when in range of the EAS monitoring system. For example, the EAS monitoring system creates a surveillance zone at an access point for a controlled or monitored area. When a security tag attached to an item enters the surveillance zone, an alarm is triggered indicating the unauthorized removal of the item from the controlled area.
Several security tag attachment mechanisms have been implemented for attaching a security tag to an item. For example, as illustrated in
To remove the tag 10 from the item, a magnetic field is applied to wedge element 14 that causes a magneto-mechanical response from the wedge element 14, i.e., wedge element 14 is pulled down towards magnet. The resulting magneto-mechanical response of wedge element 14 exceeds the bias force, thereby re-positioning wedge element 14 to the unlock position by compressing rubber spring 18, i.e., wedge element disengages tack 12. A perspective view of wedge element 14 is illustrated in
While the elongated configuration of wedge element 14 and rotational axis 16 positioned at one end of wedge element 14 help maximize the magneto-mechanical response of wedge element 14, the elongated configuration is susceptible to external mechanical forces. For example, a rotational force similar to that of the magneto-mechanical response of wedge element 14 can be accomplished by mechanical means in which the effective length of the moment arm of wedge element 14 causes wedge element 14 to impart a rotational force on rubber spring 18 sufficient to dislodge wedge element 14 from tack 12. In other words, a thief can deliver a well-placed external blow to security tag 10 to cause wedge element 14 to compress rubber spring 18, thereby temporarily moving wedge element 14 to the unlock position such that tack 12 can be removed.
In order to reduce the susceptibility of magnetic locks to external mechanical forces or impulses, i.e., a thief banging the tag on a surface, several approaches have been proposed. Once approach involves using a spring with a greater spring force, i.e., stiffer spring, in order to counteract the external mechanical forces. However, a stiffer spring results in a magnetic lock that requires a stronger and typically more expensive magnet to overcome the greater spring force of the spring, which may also result in an EAS tag that is harder to detach.
Another proposed approach is to use a security tag with multiple wedging elements that are actuated by multiple magnets in which each magnet corresponds to a respective wedging element. In other words, each wedging element must be in matching arrangement with each of the magnets such that each wedging element unfastens from the inserted tack. In order for a thief to remove the tag, the thief would have to simultaneously apply a mechanical force to each wedging element in specific directions to get each wedging element to move in a particular direction away from the pin/tack. While this approach reduces the susceptibility of the magnetic lock to external forces, the use of multiple wedging elements requires more precise placement of the tag on the detaching magnet arrangement that may create additional complexity and cost.
The present invention advantageously provides a system, device and method for an improved security tag locking mechanism.
According to one embodiment, a security tag is provided. The security tag includes a housing and a latching element disposed within the housing and positionable in a lock position and in an unlock position. The latching element includes a pivot axis. The latching element has a substantially balanced rotational response about the pivot axis when exposed to an external physical mechanical impulse. The security tag further includes a bias element that releasably positions the latching element in the lock position.
According to another embodiment, a security system including a security tag is provided. The security tag includes a housing and a pin in which the pin is removably insertable into the housing. The security tag further includes a latching element disposed within the housing and positionable in a lock position and in an unlock position. The latching element includes a pivot axis. The latching element has a substantially balanced rotational response about the pivot axis when exposed to an external physical mechanical impulse. The security tag further includes a bias element that releasably positions the latching element in the lock position. The latching element releasably engages the inserted pin when in the lock position.
According to another embodiment, a latching element for use in a security tag is provided. The latching element includes a center of gravity and a pivot axis. The pivot axis is disposed substantially near the center of gravity. The plurality of pivot tabs are disposed along the axis and rotatable about the pivot axis.
According to another embodiment, a security system including a security tag is provided. The security tag device includes a housing and a pin in which the pin is removably insertable into the housing. A first latching element is disposed within the housing and positionable in a first lock position and in a first unlock position. The security tag further includes a first bias element in which the first bias element releasably positions the first latching element in the first lock position. The first latching element releasably engages the inserted pin when in the first lock position. The security tag further includes a second latching element disposed within the housing and positionable in a second lock position and in a second unlock position. The security tag further includes a second bias element in which the second bias element releasably positioning the second latching element in the second lock position. The second latching element releasably engages the inserted pin when in the second lock position.
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
The present invention advantageously provides a system, device and method for removable security tags. Accordingly, the system, device and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements.
Referring now to the drawing figures in which like reference designators refer to like elements there is shown in
Security tag 24 may be made out of semi-hard and/or rigid material such as injection molded Acrylonitrate-Butadience-Styrene (ABS) plastic or polycarbonate constructed using various materials such as metal and/or plastic. While security tag 24 is illustrated having an elongated shape, other tag shapes may be used based on design need. For example, other security tag 24 shapes may be implemented based at least in part on detacher 28 configuration.
Detacher 28 includes detacher housing 32, receiving aperture 34 and magnetic element 38, among other components. Receiving aperture 34 is surrounded by bezel 36 in which receiving aperture 34 receives at least a portion of security tag 24, i.e., tag protrusion 30. Receiving aperture 34 helps ensure proper tag alignment with magnetic element 38. Magnetic element 38 such as a magnet or multiple magnets provides a magnetic field (not shown) that repositions latching element (not shown) in an unlock position.
Referring to
Security tag 24 further includes bias element 54 that releasably positions latching element 52 in a lock position such that latching element 52 removably engages groove 42 when pin 40 is inserted into security tag 24 via tag aperture 44. Lock and unlock positions of latching element 52 are discussed in detail with respect to
A perspective view of latching element 52 provided in accordance with the principles of the present invention is described with reference to
Latching element 52 further includes planar portion 64 and one or more pivot tabs 66 (collectively referred to as “pivot tab 66”) extending from planar portion 64 along lateral pivot axis 62 and being rotatable about lateral pivot axis 62. In particular, the location of pivot tab 66 establishes lateral pivot axis 62 of latching element 52. Planar portion 64 may be asymmetric or substantially symmetric about lateral pivot axis 62. While pivot tab 66 is shown being substantially rectangular or rectangular prism shaped, other pivot tab 66 shapes may be used that allow rotational movement of pivot tab 66 while inserted within recess 50. Moreover, one or more pivots tabs 66 may be similar in shape and/or different in shape depending on design need.
While planar portion 64 is shown having a substantially square profile, other symmetrical or asymmetrical shapes may be used in accordance with the principles of the invention such as an asymmetrically shaped planar portion 64 having a center of gravity located at or substantially near lateral pivot axis 62. Planar portion 64 includes first portion 68 having a first end 70 and second portion 72 having a second end 74 in which first portion 68 and second portion 70 are rotatable about lateral pivot axis, 62, i.e., first end 70 and second end 74 are rotatable about lateral pivot axis 62. In particular, first portion 68 is substantially symmetric to second portion 72 such that the center of gravity of latching element 52 or planar portion 64 is located at or substantially near lateral pivot axis 62. In one embodiment, first portion 68 may be asymmetric second portion 72 in which the center of gravity of latching element 52 and/or planar portion 64 is located at or substantially near the pivot axis 62 such that latching element 52 and/or planar portion 64 has a balanced rotational response about pivot axis 62 when subjected to an external physical mechanical impulse. In other words, the rotational response of first portion 68 is arranged to substantially equal the magnitude of the rotational response of second portion 72 when the external impulse applied to tag 24. For example, when an external mechanical force or impulse is applied to tag 24, the rotational response of first portion 68 and second portion 72 substantially cancel each other as the two rotational responses are substantially equal but directed in opposite rotational directions. In contrast, when latching element 52 is exposed to magnetic field 76 (
Latching element 52 may be composed of one or more magnetic materials such that first portion 68 and corresponding first end 70 has a different magnetic response than second portion 72 and corresponding second end 74 when latching element 52 is exposed to magnetic field 76 (
While latching element 52 is shown as being substantially symmetrical about lateral pivot axis 62, at least a portion of latching element 52 may be asymmetric about lateral pivot axis 62. In another embodiment, latching element 52 may have one or more apertures such that the mass of latching element 52 is reduced, e.g., one or more apertures located at or near the center of the latching element. Reducing the mass of latching element 52 advantageously reduces the rotational inertia of latching element 52 and lowers the required bias force by bias element 54 needed to position latching element in the lock position when subjected to an external mechanical impulse.
Referring to
Positioning latching element 52 such that the center of gravity of latching element 52 or planar portion 64 is positioned at or substantially near lateral pivot axis 62 helps minimize the rotational response from an external mechanical force or impulse. In particular, pivot axis 62 and center of gravity of latching element 52 are within a distance of up to approximately twenty percent of a length of latching element 52 from each other so that latching element 52 is considered substantially balanced. Applying an external mechanical force, shock, acceleration or deceleration to latching element 52 by hitting or shaking security tag 24 creates a first rotational response on first portion 68 and second rotational response on second portion 72, in which latching element 52 is designed such that the first and second rotational responses counteract each other in order to minimize the net rotational response of latching element 52. By minimizing the net rotational response of latching element 52, bias element 54 is able to help keep latching element 52 substantially in the locked position, i.e., latching element 40 remains removably engaged to groove 42 of inserted pin 40, even in the presence of external physical mechanical forces or physical mechanical impulses. In other words, latching element 52 or planar portion 64 having a center of gravity at or substantially near lateral pivot axis 62 helps negate the effects of external mechanical forces applied to latching element 52, i.e., reduces the effects of mechanical forces caused by banging or shaking security tag 24.
Referring to
Referring to
While latching element 52 is disengaged from pin 40, tack 26 may be removed from security tag 24, thereby detaching security tag 24 from article 78. Bias element 54 repositions latching element back in the lock position once security tag 24 is no longer proximate detacher 28 or once the bias force provided by bias element 54 exceeds the resulting rotational response of latching element 52.
Referring to
Latching element 80 may be re-positioned or released to a second unlock position when exposed to magnetic field 76 similar to latching element 52. In particular, first and second portions of latching element 80 may have different magnetic response similar to latching element 52 such that the resulting rotational result of latching element 80 exceeds the bias force being provided by second bias element 84. While second latching element 80 is illustrated being opposite latching element 52, one of ordinary skill in the art will recognize that the second latching element may be positioned in another location within security tag 24 that allows both latching element 52 and second latching element 80 to engage one or more grooves 42 associated with pin 40. Further, latching element 52 and/or second latching element 80 may be unbalanced by greater than twenty percent since an impact of the physical mechanical impulse is attenuated by the separate latches located at multiple positions/locations within security tag 24. While latching element 52 and second latching element 80 are shown engaged to groove 42 at the same level or height, latching element 52 may engage a different level groove 42 than second latching element 80. In one embodiment, the separate latches may be substantially orthogonal to each other i.e., substantially forming a right angle when viewed from the top or bottom. Also, it is contemplated that more than two latching elements and bias elements may be incorporated within security tag 24.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.
Number | Date | Country | |
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61630271 | Dec 2011 | US |