Abstract:
A screw-on cap ( 31 ) for a recipient including a retention flap ( 33 ) and a locking device comprising a first rib and a second rib ( 16 ), such that in the first screwing on of the screw-on closure ( 31 ) the retention flap ( 33 ) is deviated so as to be able to pass between the first rib and the second rib ( 16 ) and in the final position, the retention flap ( 33 ) butts against a contact surface of the second rib ( 16 ) in a secure and reliable manner.

Description:
OBJECT OF THE INVENTION  
       [0001]     The present invention refers to a screw-on closure or cap for closing a recipient.  
         [0002]     More specifically, the present invention refers to a screw-on cap comprising at least one detachable retention flap which can be screwed on or screwed off an outer screw thread belonging to a container for the purpose of preventing undue tampering of the contents stored inside the recipient.  
       STATE OF THE ART  
       [0003]     Different sealing systems suitable for closing a recipient are currently known. Said sealing systems have the function of assuring the tamper-resistance of the contents stored in the recipient or container.  
         [0004]     A sealing system usually includes a tamper-resistant band joined to a screw-on cap or closure. Said bands, just like the caps to which they are incorporated, are cylindrical and are vertically joined to the also cylindrical body of the cap or closure in the lower portion thereof and are provided with different internal stop profiles assuring, after the initial screwing on of the cap on the threaded neck of the container, the tamper-resistance of the container and its contents by means of the housing of said stop profiles arranged on the tamper-resistant bands, under a circular ring of a diameter exceeding that of the profiles provided on the threaded neck of the container after the screw thread area, which prevents it from being unscrewed without previously breaking the connections arranged for that purpose between said band and the body of the cap.  
         [0005]     The effectiveness of the different existing tamper-resistant bands incorporated to screw-on caps or closures is measured upon or in the moment of the first opening of the container, a moment in which they must have enough resistance so as not to allow unscrewing the cap or closure without previously separating, by breaking, the corresponding connections joining said tamper-resistant bands to the body of the cap or closure, which determines, according to the result, the evaluation of the efficacy it affords to the manufacturer and the end consumer to trust in a given type of cap or closure or not, the tamper-resistance of which must be as evident as possible.  
         [0006]     However, this type of sealing systems has some drawbacks resulting, for example, from the existence of a circular ring under the screw thread/screw threads on the neck of the recipient. Therefore, upon performing the screwing on operation, the stop profiles need to surpass the diameter of the screw threads of the neck of the container, and then that of the circular ring under which it must be located at the end of the run. As a result, to perform said screwing on in the filling line, it is necessary to carry out a high screw torque to assure an effective screwing on, which on many occasions cannot be specified, and on other occasions deforms the outer appearance of the screw-on cap due to an excess.  
         [0007]     Another problem is that the functioning of current tamper-resistant systems is not absolutely reliable either, that is, they do not 100% assure the leak-tightness of the container due to the breaking or detaching of the tamper-resistant band incorporated to the cap, since any partial turn prior to the complete unscrewing of the cap or closure causes a loss of the leak-tightness, and therefore the real possibility of a leak or introduction of liquid into the container without the band having been broken or detached.  
         [0008]     This is commonly and easily seen in a container containing, for example, a carbonated beverage. Upon beginning to unscrew the cap, there is an audible noise caused by the carbonated gas leaving the inside of the container. It must be noted that in that instant, the cap and tamper-resistant band are still joined.  
         [0009]     If the action of unscrewing the cap is stopped in that instant in which the tamper-resistant band and the cap are joined, just as gas left the container, liquid can also be extracted, and therefore it is possible to introduce liquid into the container. Therefore, the initial contents of the container may be altered, and as a result the end consumer may loose trust in the contents, which would result in a loss of sales for the manufacturer.  
         [0010]     It is therefore necessary to develop a screw-on cap which, in cooperation with a mouth of a recipient, completely prevents the possibility of tampering with the contents stored in the recipient and further enhances the trust of both the manufacturer and the end consumer in the tamper-resistant system installed in the container.  
         [0011]     Document D1 US 3805987 discloses a container and screw cap closure such that which the cap, once installed, cannot be removed without so damaging its external rim that the damage will be visible and evident to anyone using the container and cap thereafter. However, it is possible slightly movements of the cap in both directions without damaging the tampering proof.  
         [0012]     Document D2 W095/28334 discloses a thermoplastic closure ( 1 ) having an annular internally threaded skirt ( 2 ) portion; one or more portions of the skirt beneath the internally threaded portion being configured as a flap ( 7 ) capable of folding radially outwardly with respect to the skirt about a vertical hinge ( 12 ). This documents has the same problem that the above document D1 .  
       CHARACTERIZATION OF THE INVENTION  
       [0013]     The tamper-resistant system of the present invention comprises a screw-on closure or cap including a retention flap and cooperates with a locking device comprised on the neck of a recipient which in turn includes a first rib and a second rib, such that in the first screwing of the screw-on closure the retention flap deviates towards the axis of the recipient in order to pass between the first rib and second rib, and in the end position of the retention flap butts against the second rib in a secure and reliable manner.  
         [0014]     The tamper-resistant system of the present invention is advantageous because it eliminates the drawbacks previously set forth, those pertaining to the manufacture, those pertaining to its application in filling lines, and especially because it assures the tamper-resistance of the contents of a container before the first use.  
         [0015]     An object of the invention is to develop a simple tamper-resistant system of low manufacturing cost and easy application in a filling line, and which prevents total or partial tampering of the contents stored in a recipient incorporating said tamper-resistant system.  
         [0016]     Another object of the invention is to assure the existence of evidence in the tamper-resistant system in the event of an attempt to tamper with the contents of the container that is easily identifiable both by the manufacturer and by the end consumer.  
         [0017]     Another object of the invention is to eliminate the tamper-resistant band of other systems so as to simplify the container recovery line in the recycling industry, since if there is no tamper-resistant band on the neck of the container to be recycled, it is possible to eliminate the tool responsible for removing said band from the neck of the recipient. It must be noted that the container and the tamper-resistant band are made of different materials, therefore they must be separated in order to be recovered.  
         [0018]     Yet another object of the invention is to simplify screw-on cap manufacture and filling line application processes.  
         [0019]     It must be noted that merely eliminating the resistance of the stop profiles incorporated on current tamper-resistant bands allows simplifying and economizing the manufacture of the tools or molds on one hand, and improving industrial efficacy on the other. All this is done without jeopardizing the industrial processes and tools for the containers which, if desired, can be lighter in weight without losing strength as a result.  
         [0020]     Upon eliminating the current stop profiles from the neck of the container, the screwing resistance is reduced to a maximum, allowing high accuracy and a low screw torque, which results in the effectiveness of the application or capping machines, increasing their performance and operating life.  
         [0021]     Another objective of the invention is to improve the efficacy, operating life and quality of screw-on cap manufacturing processes. As a result, the manufacturing and filling system is also low-cost. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0022]     Devices materializing the invention will now be described, by way of example only, in reference to the attached schematic drawings, wherein:  
         [0023]      FIG. 1  shows a perspective view of a neck of a recipient according to the invention,  
         [0024]      FIG. 2  shows a plan view of the neck of the recipient according to the invention,  
         [0025]      FIG. 3  shows a perspective view of a screw-on closure on the neck of the recipient according to the invention,  
         [0026]      FIG. 4  shows a plan view of how the screw-on closure remains after the first screwing on according to the invention,  
         [0027]      FIG. 5  shows a perspective view of another embodiment of the screw-on closure according to the invention, and  
         [0028]      FIG. 6  shows a plan view of how the screw-on closure of the previous figure remains after the first screwing on according to the invention. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0029]      FIG. 1  represents a retention or locking device  15 ,  16  located under the outer screw thread or threads  13  located on the neck  12  of a container or recipient  11 . The recipient  11  is preferably made of a plastic material so that the material can be injected in an injection mold. The recipient  11  is suitable for storing a substance such as a liquid, a carbonated beverage or the like.  
         [0030]     The retention device comprises a first projection  15  and a second projection  16  or ribs close to the contact edge  14  of each one of the two parts or halves constituting the container  11 .  
         [0031]     As can be seen in  FIG. 2 , each half of the container includes a first rib  15  and a second rib  16 , each one of them located at one of the contact edges corresponding to one half of the container  11 . For example the first rib  15  is in contact with the neck  12 , that is, in contact with the outer face of the cylinder of the neck of the container  11  and on a horizontal base ring  17  which is located under the screw thread  13 .  
         [0032]     On the opposite edge said half of the container includes the second rib  16  arranged on the base ring  17 , externally and separately, and not in contact with the cylinder of the neck  12 . Therefore, when the contact edges of both halves of the container are joined, two sets of locking devices  15 ,  16  are formed such that each one of the locking devices comprises a first rib  15  from one half and a second rib  16  from the other half of the container  11 .  
         [0033]     Regarding  FIGS. 1 and 3 , it must be noted that both ribs  15 ,  16  are facing at the same height on the base of the neck  12  and on the base ring  17  of the container  11 , radially displaced from one another in order to prevent a retention flap  33  belonging to a screw-on cap or closure  31  from being radially displaced towards the axis of the container  11  when said cap  31  is unscrewed for the first time.  
         [0034]     When the cap  31  is screwed on the retention flap is radially pressed towards the axis of the container, inwardly, by the second rib  16  and once said second rib  16  is overcome, the screw-on cap  31  has reached the final closure position for the screw-on cap  31 .  
         [0035]     As previously mentioned, in this position the retention flap  33  cannot be radially displaced towards the axis of the container  11 , said movement is prevented by the first rib  15  which is in contact with the neck  12  of the container  11 .  
         [0036]     Returning to  FIG. 1 , it must be noted that the first rib  15  comprises a deviation bevel on the introduction side, that is, the side closest to the contact edge  17 , acting in the screwing on direction such that when the screw-on  31  cap is screwed on, the retention flap  33  is radially deviated outwardly from the axis of the container  11 , being able to pass between the outer face of the neck and the concave inner face of the second rib  16  in the first screwing on of the cap  31 .  
         [0037]     Again in relation to  FIGS. 1 and 3 , the first rib  15  has the purpose of limiting the radial run of the retention flap  33  towards the axis of the container  11  in the final closure position for the screw-on cap  31  once the latter has been located after the first screwing on, and thus preventing the cap  31  from becoming unscrewed without tampering or previously detaching said flap  33 , for example by breaking a breakable bridge or tear strip  34  and/or a film hinge  35  by means of which the retention flap is joined to the skirting or sleeve of the cap  31 . It must be noted that the tear strip  34  is located on the side opposite to the hinge  35 .  
         [0038]     The first rib  15  extends like a circular arch-shaped curb along one part of the contour of the neck  12  of the container  11 , that is, in contact with the outside of the neck of the container, and on the horizontal base ring  17 .  
         [0039]     Additionally, the second rib  16  is molded on the base ring  17  in a pyramidal quasi-triangular wedge shape along one part of the contour of the base ring  17  such that its concave inner face is arranged with a predetermined spacing regarding the outer face of the neck  12  of the container  11 .  
         [0040]     The inner face of the second rib  16  acts in the screwing on direction such that when the screw-on cap  31  is screwed on, the retention flap  33  is radially deviated towards the axis of the container, being able to pass between the outer face of the neck  12  and the inner face of said second rib  16  in the first screwing on of the cap  31 .  
         [0041]      FIG. 3  shows the position of the closure  31  after the first screwing on the neck  31 . The screw-on cap is molded in a thermoplastic material, in a single piece, suitable for being used in cooperation with the locking device  15 ,  16  in a tamper-resistant system preventing illicit tampering of the contents stored in the recipient  11 .  
         [0042]     The screw-on cap  31  comprises a cap bottom and a cap sleeve or skirt  32  with an internal threading, not shown, so that the cap  31  can be screwed on and off the outer screw thread/threads  13  belonging to the neck  13  of the recipient  11 .  
         [0043]     The retention flap  33  is molded in the lower end area of the cap sleeve  32  such that it outwardly projects, being oriented approximately tangentially in the cap sleeve  32 , as is seen in FIGS.  3  to  6 . The retention flap  33  projects from the cap sleeve  32  opposite to the screwing on direction.  
         [0044]     The retention flap can be separated and easily molded on the skirt  32  of the screw-on cap. As a result, the screw-on cap  31  with the retention flap  33  can be easily manufactured unitarily in a single piece from a low-cost material, such as plastic, which has a suitable flexibility allowing the flap  33  to pass between the neck  13  and the second rib  16  after the first screwing on.  
         [0045]     The retention flap ends on its front face in a stop surface which is oriented approximately radially, whereas the end of the second rib  16  located in the unscrewing direction forms a contact surface which is likewise oriented approximately radially, such that after the first screwing on of the cap  31 , both surfaces are in contact for the purpose of preventing the unscrewing of the cap  31 . When the cap is unscrewed for the first time, the retention flap  33  must be radially displaced outwardly since the second rib  16  prevents it from being radially displaced inwardly, therefore the flap  33  is completely or partially detached and entails that the tear strip  34  and the hinge  35  have been broken. Therefore, the end consumer and/or manufacturer have proof that the container has been opened by them. In another case, the cap shows proof of prior tampering and therefore the end consumer may suspect that the contents of the container  11  have been altered.  
         [0046]     It must be noted that at its stop surface, the retention flap  33  may include a deviation bevel on the inner face acting in the unscrewing direction such that it facilitates the unscrewing action of the screw-on cap  31 . In the first unscrewing, the retention flap  33  is radially deviated outwardly of the container  11 , breaking the tear strip  34  and furthermore, it will also cause the complete or partial breakage of the film hinge  35  on the retention flap  33 , being able to pass over the outer convex face for the second rib  16  after the first unscrewing of the cap  31 .  
         [0047]     The retention flap  33  projects from the sleeve  32  of the cap  31  such that in the retained position it partially and reliably covers with its stop surface the contact surface of the second rib  16  so as to maintain a safe retention joining acting only in the direction for the first unscrewing of the screw-on cap  31 .  
         [0048]     In reference to  FIGS. 3 and 4 , a braking means  36  can be molded such that it projects outwardly from the axis of the cap  31  with a trapezoidal shape on the lower edge of the sleeve  32  of the cap  31 , at a predetermined distance from the stop surface of the retention flap  33  in the screw-on direction so that the cap  31  can be stopped appropriately after the first screwing on, that is, contact between the stop surface of the flap  33  and the contact surface of the second rib ( 16 ) is assured.  
         [0049]     In reference to  FIGS. 5 and 6 , it must be noted that the number of retention flaps  33  can vary according to the number of screw threads of the neck  12  of the container  11 , such that a single screw thread will have a single retention flap  33  on the cap  31 , a releasable and elastic flap, and one or two for retention flaps  51  fixed on a circular tamper-resistant band  52  like those currently existing. Similarly, a neck with two threads will have two or four fixed retention flaps  51 , and a neck with three threads will have two, four or six fixed retention flaps. As is shown in  FIG. 6 , in all cases two retention devices  15 ,  16  on the base ring  17  separated 180° from on another are enough, as a result, the fixed retention flap act in twos.  
         [0050]     Therefore, for the opening of the container by means of unscrewing the cap, it is necessary to instantly break the connections between the tamper-resistant band  52  and the sleeve  32  of the cap  31  in the case of fixed and rigid retention flaps  51 .  
         [0051]     In summary, the cooperation of the retention flap  33  and the locking device  15 ,  16  acts such that it necessarily facilitates its passing and coupling of the cap  31  in the screwing on direction and, by means of the controlled run of the threading on the neck  12  of the container  13  and at its end, it is made to necessarily coincide at one previously determined point, facing them at their flat surfaces, which will prevent its unscrewing from the very start of the unscrewing run and as a result will fully assure that the contents of the container have not been unduly tampered with, and it further facilities outer, easily detectable evidence of an illicit tampering of the cap.