Patent Publication Number: US-9406425-B2

Title: Magnetic decoupling unit for releasing antitheft devices

Description:
TECHNICAL FIELD 
     Example embodiments of the present invention generally relate to magnetically releasable antitheft devices and, more particularly, relate to a magnetic decoupling unit capable of removing several types of magnetically releasable antitheft devices. 
     BACKGROUND 
     Antitheft devices are designed to prevent unauthorized removal of an item from a secured location. These antitheft devices are commonly used, for example, in a retail sales environment such as a clothing store. The antitheft device is placed on an item such as an article of clothing and is removed by a store clerk after the customer has paid for the article. If someone tries to remove the article of clothing from the store without first removing the antitheft device, an alarm will sound or the store clerk will otherwise be notified. 
     Antitheft devices are often attached to the article of clothing using a magnetically releasable mechanism. This mechanism, a component of which may be, for example, a metal pin, locks the antitheft device onto the article of clothing such that it may only be removed when the antitheft device is in the presence of a magnetic field of sufficient strength and dimension to unlock the metal pin and allow its removal. 
     Magnetically releasable antitheft devices come in a variety of forms, each of which may require a slightly different magnetic “key” or “detacher” to unlock the device. For example, single pin or single clutch devices use a single locking pin which may be unlocked by a localized vertical magnetic field. By contrast a double clutch or double leaf spring devices may have two locations where a sufficient magnetic field is needed. 
     In order to prevent the theft of electronic media (e.g., DVDs, CDs, etc.) and other products, another type of antitheft device may be secured along the length of an edge of an electronic media case or other lockable unit. When in place, the antitheft device prevents the case from being opened to remove the media and will trip an alarm if removed from the store. To release this type of antitheft device, an elongated horizontal magnetic field may be used. 
     Because stores may use multiple types of antitheft devices, and because each antitheft device may require a different key or detacher to magnetically unlock and release it, it is desirable to have a single magnetic decoupling unit that can be used to magnetically release each of a plurality of common antitheft devices. 
     BRIEF SUMMARY OF SOME EXAMPLES 
     Some example embodiments of the present invention recognize and address considerations of prior art constructions and methods. 
     An example embodiment of a magnetic decoupling unit may include a magnet assembly for decoupling a plurality of different types of magnetically releasable antitheft devices. The magnet assembly may comprise a first magnet having a magnetic orientation along a first direction; a plurality of magnets adjacent to and surrounding the first magnet, the adjacent magnets defining an opening above the first magnet, each adjacent magnet having a magnetic orientation orthogonal to the first direction; a first side magnet disposed adjacent one of the magnets adjacent to the first magnet, the first side magnet having the same magnetic orientation as the first magnet. 
     Other aspects and advantages of the present invention will be apparent from the following description and the appended claims. Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of example embodiments in association with the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       Having thus described example embodiments of the present invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
         FIG. 1  illustrates a perspective view of an antitheft tag removal device containing a magnetic decoupling unit in accordance with an example embodiment of the present invention; 
         FIG. 2  illustrates a perspective side view of a magnetic decoupling unit in accordance with an example embodiment of the present invention; 
         FIG. 3  illustrates an exploded perspective side view of a magnetic decoupling unit in accordance with an example embodiment of the present invention; 
         FIG. 4A  illustrates a top view of a magnet assembly in accordance with an example embodiment of the present invention; and 
         FIG. 4B  illustrates a side view of a magnet assembly in accordance with an example embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to example embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations. 
     Example embodiments of the present invention relate to an improved magnetic decoupling unit for use with a plurality of different types of magnetically releasable antitheft devices. The magnetic decoupling unit includes a first magnet that may be centrally located and surrounded by a plurality of adjacent magnets and at least one side magnets. Some of the magnets are arranged with their magnetic orientations orthogonal to each other to increase the axial magnetic field through the superposition of the magnetic fields of each magnet. In addition, two side magnets (e.g., a first side magnet and a second side magnet) are included to increase the axial magnetic field as well as to provide an elongated, horizontally oriented magnetic field. When configured in this manner, the magnet assembly is capable of unlocking most common types of magnetically releasable antitheft devices. 
       FIG. 1  shows an antitheft tag removal device  10  in accordance with an example embodiment of the present invention. The device  10  comprises a magnetic decoupling unit  12  which is connected to the device base  14  by a tether  16 . As commonly used in a retail store, the device base  14  may be securely fixed or otherwise provided at the checkout counter beside a point of sale (POS) terminal. Antitheft devices are typically placed on the store merchandise and the antitheft device is removed by placing it on the magnetic decoupling unit  12  in the required orientation to release the internal locking mechanism. However, the store clerk can optionally remove the magnetic decoupling unit  12  from the base  14  by pressing the release button  18 . This allows the clerk to use the magnetic decoupling unit  12  as a handheld device. When used in this manner, the tether  16 , which is secured to the base  14 , may ensure that the magnetic decoupling unit  12  is not removed from the checkout counter. 
       FIGS. 2 and 3  show an assembled and exploded view, respectively, of an exemplary magnetic decoupling unit  12  that might be fixed in the antitheft tag removal device  10  of  FIG. 1 . The magnet assembly  28  may be placed inside the magnet housing  20 , which may be non-magnetic, being constructed from a non-ferromagnetic material such as plastic or stainless steel. The magnet assembly may also be covered by a housing cover  22  constructed from non-ferromagnetic material. The housing cover  22  may have an aperture  24  and insert  26 , for example, for receiving single clutch antitheft tags. 
     Referring now to  FIGS. 4A and 4B , an example embodiment of the magnet assembly  28  may be comprised of seven magnets. A first magnet E is positioned below the cover aperture  24  and is magnetically oriented in a vertical direction (as can be seen from the magnetic orientation indicators). The first magnet E is shorter than the other magnets in the magnet assembly  28  in order to accommodate the insert  26  for receiving a single clutch antitheft tag. Four magnets—B 2 , D, F 1 , and F 2 —are arranged adjacent to the first magnet E. Each of these magnets is magnetically oriented in a direction orthogonal to the vertical orientation of the first magnet E and magnetically directed toward the first magnet E as shown in  FIG. 4A . In this regard, the first magnet E may have the North pole oriented vertically upward, while the North poles of adjacent magnets D and B 2  may each be oriented toward the first magnet E. The North poles of adjacent magnets F 1  and F 2  may also each be oriented toward the first magnet E. The North pole of the first side magnet C may be oriented in substantially the same direction as the orientation of the North pole of the first magnet E (i.e., vertically upward). Meanwhile, the orientation of the North pole of the second side magnet B 1  may be oriented toward the first magnet E. 
     This magnet configuration generates a strong axial magnetic field directed along the vertical direction of first magnet E. This axial magnetic field is ideal for magnetically releasing the pins from single clutch antitheft tags. By orienting the four magnets adjacent to first magnet E as shown in  FIGS. 4A and 4B , an axial magnetic field is generated that is stronger than the magnetic field generated by the first magnet E alone. The magnetic field also extends for a length of one inch or longer so that magnet assembly  28  is capable of releasing double clutch antitheft tags. 
     In an example embodiment of the present invention, two additional magnets—second side magnet B 1  and first side magnet C—are included in the magnet assembly  28  and placed adjacent to one of the magnets adjacent to the first magnet E (i.e., adjacent to magnet D as shown in  FIGS. 3 and 4 ). First side magnet C is oriented such that it has the same magnetic orientation as the first magnet E and second side magnet B 1  is oriented such that it has the same magnetic orientation as magnet D. A metal endplate A is placed on the end of the assembly. Such an assembly generates an elongated horizontal magnetic field that runs transverse to the axial magnetic field described previously, and can be used to magnetically release an antitheft device on an electronic media storage case. The vertical magnetic field is also strengthened by the presence of the side magnets. The resulting magnet assembly  28  can magnetically release a variety of common types of magnetically releasable antitheft devices. 
     As can be appreciated from  FIGS. 3, 4A and 4B , the magnets B 1 , B 2 , C, and D may each be provided as rectangular prism shapes that have the same height and length dimensions. However, the widths of at least some of magnets B 1 , B 2 , C, and D may be different. In particular, the first side magnet C may be wider than magnets B 2  and B 1  (which may have equal widths). Meanwhile, magnets B 2  and B 1  may be wider than magnet D, which is in turn wider than the metal endplate A. The first magnet E may have the shape of a cylinder, and magnets F 1  and F 2  may fit over opposing sides of the first magnet E, spaced apart from each other. Thus, while magnets F 1  and F 2  may be substantially rectangular prism shaped, each such magnet may include a curved trench provided at a surface of at least a portion of the sidewalls that face each other to enable the magnets F 1  and F 2  to interface closely with the first magnet E. Magnets F 1  and F 2  may have the same height dimensions as magnets B 1 , B 2 , C, and D, but may have less than half the length of the magnets B 1 , B 2 , C, and D. The diameter of the first magnet E may be larger than the width of any of the other magnets B 1 , B 2 , C, D, F 1  and F 2 . 
     In some embodiments, the magnet assembly  28  may sit on top of a non-ferromagnetic base plate (not shown). Alternatively, this base plate may be made of magnetic material in order to help shield a portion of the magnetic flux generated on the underside of the magnet assembly  28 . The magnets may be made from a variety of magnetic materials, such as ferrite, samarium cobalt, or neodymium iron boron. 
     While one or more example embodiments of the present invention have been described above, it should be understood that any and all equivalent realizations of the present invention are included within the scope and spirit thereof. The embodiments depicted are presented by way of example only and are not intended as limitations upon the present invention. Thus, it should be understood by those of ordinary skill in this art that the present invention is not limited to these embodiments since modifications can be made. Therefore, it is contemplated that any and all such embodiments are included in the present invention as may fall within the scope and spirit thereof.