Patent Publication Number: US-2009217716-A1

Title: Security Opening Mechanism

Description:
OBJECT OF THE INVENTION 
     The present invention generally relates to an opening mechanism for a security device, the security device being intended for being assembled on or containing an object in a display in a shop. 
     The present invention more specifically relates to an opening mechanism for a security device which forms a lock coupling, in a locked position, in said security device, the opening device usually being kept in a locked position so that it can be actuated by generating a thermal gradient on said opening mechanism, taking it from the locked position to an open or unlocked position. 
     STATE OF THE ART 
     Anti-theft containers are currently known which are used to store objects and which in turn allow a potential buyer to examine the object contained in said container. The anti-theft container cannot be opened by the public examining the merchandise because said container comprises a magnetically operated opening mechanism which locks the opening of the mentioned container. 
     The opening mechanism comprises a guided metallic pin which is required in the engaging position, namely in a locked anti-theft container, due to the action of a spring. The opening action is carried out by means of a magnetizing device outside the container which is usually located at the shop cash register. 
     The magnetizing device is a strong permanent magnet which extracts the guided metal pin due to the action of magnetic attraction, overcoming the antagonist effort of the mentioned spring, releasing it from a first cover of the container which can be slid in the opening direction of the container, until sufficiently uncovering the rest of the container so as to allow the extraction of the object contained inside the mentioned anti-theft container and being able to be given to the customer who has requested it. 
     This type of security system has a series of drawbacks, such as the fact that the permanent magnet of the shop can be replaced by a strong permanent magnet which is carried by a potential buyer; accordingly the combined security system previously described does not prevent merchandise displayed on a shelf of a shop from being taken out of the shop without permission. 
     One way to prevent the permanent magnet of the shop from being replaced is to install in the plastic container an opening and locking mechanism comprising a spring which exerts a resistant force having a magnitude that requires a very strong magnet, which translates into the use of a very large, cumbersome and heavy substitute magnet that would have to be carried by the customer visiting the shop. Said substitute magnet would therefore be cumbersome for the customer to carry. 
     It is therefore necessary to develop a security system for merchandise on display in a shop which is secure and reliable, i.e. eliminates the possibility of substituting any of the devices forming the security systems. 
     CHARACTERIZATION OF THE INVENTION 
     The present invention aims to resolve or reduce one or more of the drawbacks set forth above by means of a security opening mechanism as claimed in claim  1 . Embodiments of the invention are set out in the dependent claims. 
     An object of the invention is to form an opening mechanism that can be opened by providing energy which is transformed into a temperature increase. 
     Another object of the invention is to provide a secure and reliable security system. 
     Yet another object of the invention is to provide a simple security system with low manufacturing costs, i.e. it is an economical and effective security system. 
     Another object of the invention is to apply the opening mechanism in a wide variety of reusable security devices for protecting objects on display, such as clothes, cassettes, compact discs and the like which, due to their high price and small size, must be protected from the fraudulent or unauthorized taking from a display shelf of a shop to a point outside the shop. 
     Yet another object of the invention is to reduce surveillance provided by other types of security systems and to reduce the damage brought about by theft. 
     Yet another object of the invention is to provide a security system which is easily manageable and requires little time to be opened by the employees of the establishment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       A more detailed explanation of the invention is provided in the following description based on the attached figures in which: 
         FIG. 1  shows a plan view in cross section along the X-X, X′-X′ axes of a security opening mechanism in the locked or closed position according to the invention, and 
         FIG. 2  shows a plan view in cross section along the Y-Y, Y′-Y′ axes of a security opening mechanism in the unlocked or open position according to the invention. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     A tamper proof security system is illustrated below in reference to  FIGS. 1 and 2 , comprising an anti-theft protection means  11  in turn including a security opening mechanism  12  to prevent the extraction of an object contained (not shown) in the mentioned anti-theft protector  11 , and an energy supply means (not shown) located close to a cash register of the shop. 
     The protector  11  comprises a case  13  forming a cavity for housing the object to be protected and a cover  14  which is interconnected to the case by hinge means  15 . 
     The opening mechanism  12  is usually located on the side opposite to the hinge  15 , on the inner side of the cavity of the case  13 , and it is facing an interlocking element  16 , shown in  FIG. 2 , projecting from the cover  14  on the distal end of the hinge  15  towards the cavity of the case  13  of the protector  11 . 
     Going back to  FIG. 1 , the protector  11  is locked, i.e. the interlocking element  16  is locked by a locking element  17 , namely a latch, included in the opening mechanism  12 . Therefore the cover of the protector  11  cannot be opened because the latch  17  engages the interlocking element  16  of the cover  14 , preventing the mentioned cover  14  from sliding to the open position shown in  FIG. 2 . 
     When the energy source is turned on and the protector  11  is close to said source, a temperature increase occurs in a thermal expansion means  18  included inside the opening mechanism  12 , causing a predetermined travel of the expansion means  18  which shifts the latch  17  such that it goes from the locked position to an unlocked position, causing the protector  11  to open and then being able to remove from the cavity of the case  13  of the protector  11  the object contained therein. 
     The energy source generates an electromagnetic field such that when the opening mechanism  12  is introduced in the electromagnetic field coverage area the electromagnetic waves of the mentioned field generate heat in the expansion means  18  such that one of its longitudinal dimensions experiences a magnitude increase. 
     The energy source comprises a winding through which an electric current flows, generating the electromagnetic field, and when the part of the display protector  11  in which the expanding means  18 , for example a bimetallic strip, is located is introduced in said electromagnetic field, it begins to heat up, this effect not occurring in the material which the display protector  11  is made of. 
     It must be noted that the energy transmitted by the electromagnetic field to the bimetallic strip  18  causes a temperature increase therein which is not transmitted to the case  13  or to the cover  14 , or to any other element of the protector  11 ; the protector  11  is therefore reusable. 
     It must be noted that no type of resistance is used as a heat source. Nor does any direct contact occur between the source and the expansion means  18 . The heat is generated due to the movement of the electrons in the bimetallic strip  18 . 
     Obviously, to generate sufficient travel of the latch  17  so as to allow the opening of the cover  14  of the protector  11 , the bimetallic strip  18  must remain in the electromagnetic field for a predetermined time period such that it assures generating a temperature gradient that exceeds a predetermined threshold level. 
     The opening mechanism  12  comprises a seat within which the expansion means  18  can be inserted, the latter having a high thermal expansion and deformation coefficient so that the expansion means  18  are shifted with respect to the initial position when the opening mechanism  12  is kept within the electromagnetic field for a predetermined time period. 
     The mentioned expansion means  18  can be given different shapes, such as a rectangular strip shape, a disc shape, a tab shape or the like. Depending on the shape of the expansion means  18 , the seat will be given a suitable shape so that the travel of the expansion means  18  unlocks the latch  17  of the cover  14  of the protector  11 . 
     It must be noted that the direction of the travel will be oriented such that it releases the latch  17 , for example the travel is carried out towards the inside of the case  13  but in other arrangements of the opening mechanism  12  it would be possible for the expansion means  18  to travel in other directions of the cavity of the case  13 , shown in  FIG. 2 . 
     Heating of the bimetallic strip  18  is very fast, therefore the time necessary for the action of opening the protector  11  to occur is very short; therefore the consumption of electrical energy is also low. 
     The energy source can be an electromagnetic induction source, for example, or any other type of energy source that is able to cause a temperature increase on the bimetallic strip  19  without any direct contact between the energy source and the bimetallic strip  18 , maintaining the physical integrity of the display protector  11 . 
     The consequence of the temperature increase in the bimetallic strip  18  causes an increase in the distance between ends, usually the longitudinal dimension, of the mentioned bimetallic strip  18  such that it becomes deformed, causing a predetermined deflection which is a function of the different thermal expansion coefficients of the components of the bimetallic strip  18 . Therefore, the expansion is transformed into a travel of the bimetallic strip  18  causing the latch  17  to travel, and accordingly the cover  14  is no longer retained by the opening mechanism  12 , the cover  14  being able to be slid off the rest of the case  13  of the protector  11  in the opening direction thereof until sufficiently uncovering it to allow the extraction of the object contained inside the anti-theft protector  11 , and being able to be given to the customer who has requested it. 
     The case  13  obviously protects, or comprises or locks merchandise such as rope, cassettes, compact discs and the like inside it. 
     The display protector  11  is made of a preferably transparent plastic material by injection and it is given a predetermined thickness which assures a predetermined degree of mechanical strength against direct impacts or attempts to open it by force. 
     The anti-theft protector  11  can be provided with one or more sensors (not shown) to activate an electric alarm system when the protector is taken out of the shop. 
     The opening mechanism  12  can be adapted to other types of anti-theft display protectors such as bands to be arranged on bottle necks, button-type anti-theft display protectors for clothing articles or the like. 
     The embodiments and examples set forth in this specification are presented as the best explanation of the present invention and its practical application, and to thus allow the persons skilled in the art to put the invention into practice and use it. Nevertheless, those persons skilled in the art will recognize that the foregoing description and examples have been presented for only illustrating the invention and as an example. As the description is given, it is not intended to be thorough or to limit the invention to the precise embodiment described. Many modifications and changes are possible in light of the preceding teaching without departing from the content and scope of the following claims.