Abstract:
In order to prevent or minimize littering, the invention proposes a plastic closure ( 1 ) having a tamper-proof element. The plastic closure has a tamper-proof element that is as small as possible, and the plastic closure is largely secured against loss. The tamper-proof element consists of a plate ( 50 ), which is formed as part of the jacket wall ( 30 ) of the cover ( 3 ) by means of designed breaking point bridges ( 51, 52 ) and lies behind a first apron ( 25 ) in the closed state before the first opening and engages in a window ( 26 ) of the first apron by means of a locking hook. After the first opening, the plate ( 50 ) is separated from the cover and is held captive between the first apron ( 25 ) and a second, inner apron ( 27 ).

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is the US national phase entry of International Patent Application no. PCT/EP2014/053127, filed Feb. 18, 2014, which claims priority to Swiss patent application no. 00583/13, filed Mar. 12, 2013. 
     TECHNICAL FIELD 
     The present invention relates to a plastic closure having a lower part with a drinking spout and a cover which is connected in one piece to the lower part by means of a hinge, and comprises a sealing plug which can be engaged in a locking manner with the drinking spout, said sealing plug being molded on the inner side of the cover surface, wherein the lower part and the cover each comprise a jacket wall, which are at least approximately flush one above the other in the closed state of the plastic closure, and that the plastic closure also comprises at least one integrity guarantee element, which is separable during the first opening of the plastic closure due to the swiveling motion of the cover relative to the lower part. 
     BACKGROUND 
     Plastic closures, which comprise a lower part and a cover connected thereto in a swiveling manner by means of a hinge, have to be secured in such a way that the consumer recognizes whether the closure may have already been opened before the purchase and whether there is therefore the risk of the contents already having been partially removed or, something which unfortunately also occurs, having been contaminated. 
     Accordingly, plastic closures having integrity guarantee elements have already been on the market for very many years. The best known form of an integrity guarantee element is the guarantee band, which originally primarily produced a connection between the plastic closure and the container on which the plastic closure is fitted. Such a guarantee band is of course sufficient in the case of a screw connection. Such a guarantee band can also be used in the case of plastic closures with a hinge or a snap-on hinge with which the lower part can be fixedly connected to the container neck, wherein such a guarantee band is usually not completely circumferential, but runs around more than 180° of the circumference. The guarantee band then comprises locking hooks usually on the inner side, i.e. on the side that is directed towards the lower part in the closed state, said locking hooks engaging in the corresponding recesses in the lower part. Before such a closure can be opened, the guarantee band must therefore first to be torn off. 
     For reasons of user convenience, integrity guarantee elements were then developed which, when the hinge connection is first opened, automatically bring about a separation of the integrity guarantee element from the part to which this integrity guarantee element is connected by predetermined breaking points. Such a plastic closure is shown for example in WO94/03371. Here, a platelet is held by predetermined breaking point bridges in the cover in its cover surface flush with said cover surface, and molded on the underside of said platelet is an arm with a terminal locking hook, which interconnects with a counter-locking hook of the lower part. During the first opening, the platelet of the integrity guarantee element is duly torn out of the cover surface of the cover and then falls down onto the cover surface of the lower part. A clearly visible integrity guarantee thus results. In addition, such a solution has the advantage that, after the first opening, tampering with the integrity guarantee element more or less to recreate the integrity state is virtually impossible. 
     WO00/41943 shows a solution for an integrity guarantee element that is also difficult to tamper with. Here, the integrity guarantee element comprises a completely separate guarantee band, which engages over protruding beads on the cover and the lower part. Such a solution has the advantage that the guarantee band can be constituted in a different color from the plastic closure itself, and thus can be readily recognized visually. Here, as in the solutions for integrity guarantee elements in common use nowadays, the separated parts are relatively large and, precisely in the case of beverages which are provided with a plastic closure with a drinking spout, these integrity guarantee elements are torn off and thrown away carelessly. 
     A solution, wherein the integrity guarantee element is not a separate loose part, is shown for example in GB-A-2269583. Here, the plastic closure is provided with a shield-shaped tilting plate which hooks on the lower part in a swiveling manner. This shield-shaped plate is pressed for the purpose of opening and a predetermined breaking point bridge is thereby destroyed. The closure can now be opened. The problem with this solution, however, is that the consumer can scarcely recognize the integrity of the product. 
     Finally, a plastic closure is known from WO98/57864, according to the preamble of patent claim  1 . This plastic closure comprises an integrity guarantee element which is molded on the jacket wall of the cover and which is intended to engage in a recess in the jacket wall of the lower part. The integrity guarantee element swivels here about the predetermined breaking points and comprises two lugs, which are intended to engage in corresponding holes in the jacket wall of the lower part. In addition, a tilting rib is formed in the recess in the lower part and the user is intended to press on the integrity guarantee element, wherein the tilting motion is intended to take place via the tilting rib, and the integrity guarantee element is thereby separated from the cover. The closure can now be swiveled upwards. This closure is problematic, inasmuch as on the one hand the user does not recognize the function and basically attempts to lift the integrity guarantee element. Furthermore, a swiveling motion about an arc-shaped hinge is extremely problematic and finally it has been shown that such a closure can be handled only with extreme difficulty on conventional assembly machines, and that a significant percentage of the closures are destroyed. On the other hand, the idea that the integrity guarantee element remains on the closure and is not therefore thrown away carelessly is in itself sensible. 
     SUMMARY 
     It is the problem of the present invention to improve a plastic closure of the type mentioned at the outset in such a way that the latter is capable of being closed in a conventional manner in standard assembly machines with a low level of rejects, the destruction of the first opening guarantee closure is more readily recognizable, and finally in a preferred embodiment the at least one integrity guarantee element is also held in such a way that it is secured sufficiently in the plastic closure against loss. 
     This problem is solved by a plastic closure having a lower part with a drinking spout and a cover which is connected in one piece to the lower part by means of a hinge and comprises a sealing plug which can be engaged in a locking manner with the drinking spout, said sealing plug being molded on the inner side of the cover surface wherein the lower part and the cover each comprise a jacket wall, which stand at least approximately flush one above the other in the closed state of the plastic closure, and that the plastic closure also comprises at least one integrity guarantee element, characterized in that the cover jacket wall is provided with at least one locking hook molded on the outer side opposite the hinge, and a first apron directed towards the cover and extending over less than half the circumference is provided on the lower part opposite the hinge and above the jacket wall of the lower part, in which first apron at least one hook locking window is formed, and a second apron running concentric with the first apron is provided, which second apron is offset inwards by at least the thickness of the jacket wall of the cover in this region, and wherein the at least one integrity guarantee element, which is separable during the first opening of the plastic closure by the swiveling motion of the cover relative to the lower part, is a partial region of the jacket wall of the cover and is provided with the at least one mentioned locking hook. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred embodiment of the subject-matter of the invention is represented in the drawing and explained in the following description. In the figures: 
         FIG. 1  shows a perspective view of the plastic closure in the opened production position, and 
         FIG. 2  shows the same closure again in a perspective view, viewed somewhat rotated and more from the side compared to  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The plastic closure is denoted overall by  1 . It comprises a lower part  2  and a cover  3 . Lower part  2  and cover  3  are connected to one another in one piece by a hinge  4 . The hinge comprises, on the one hand, a hinge piece  40 , which is connected on both sides by a film hinge  41  on the one hand to cover  3  and on the other hand to lower part  2 . Two tension bands  42  are provided symmetrical with this hinge piece  40 . The effect of this is that the hinge is a snap-on hinge. 
     Lower part  2  comprises a cylindrical jacket wall  20 , which is terminated on the upper side by a cover surface  21 . A drinking spout  22  passes through this cover surface  21 . This drinking spout  22  projects beyond cover surface  21  roughly by the height of jacket wall  20 . In order to provide sufficient drinking convenience, the drinking spout should preferably project at least overall with its uppermost edge approx. 10 mm or more above cover surface  21 . The embodiment of the spout can be almost arbitrary. In the example represented here, the drinking spout tapers upwards with a certain conicity. However, the drinking spout can also perfectly well have the shape of a dummy. The relatively widespread shapes on the market, wherein the drinking spout is tapered at half the height, also of course come into consideration here. Drinking opening  23  can be seen at the top in drinking spout  22 . The drinking opening is limited by a pulled-down collar, which comprises circumferential sealing ribs  24  on its inner side. 
     An arc-shaped, first apron  25  stands above jacket wall  20  of lower part  2  virtually in the extension thereof. Said apron is connected over the whole area and in one piece to jacket wall  20 . First apron  25  extends over less than half the circumference of jacket wall  20  of lower part  2  and its center lies diametrically opposite hinge piece  40  of hinge  4 . The height of the apron amounts to only a few millimeters and is at most roughly a third as high as drinking spout  22 . First apron  25  is provided with a recessed portion roughly in the middle on the upper edge, said recessed portion forming a grip recess  28 . Two hook locking windows  26  are molded here in first apron  25  at the side of this grip recess  28 . Said hook locking windows are rectangular perforations in first apron  25 . In principle, only one hook locking window could also be provided in the center instead of the two hook locking windows  26 . However, since the grip recess here is provided in this region, the remaining wall height is rather small and it is therefore preferable to provide the two hook locking windows  26  at the side. 
     A second, inner apron  27  is provided concentric with first apron  25 . The significance and mode of operation of said second, inner apron will be explained in greater detail later. This second, inner apron  27  is preferably at most equal in height to the outer apron, but preferably lower than outer, first apron  25 . It is also preferably constituted with a somewhat smaller length than outer, first apron  25 . 
     Cover  3  also has a circumferential jacket wall  30 . This jacket wall  30  comprises a jacket wall region  31 , which lies diametrically opposite hinge  4  and which is disposed offset inwards towards the center with respect to edge  32  by slightly more than the wall thickness of first apron  25  on lower part  2 . Since the closure is represented here in the opened state, only the inner side of cover surface  33  of cover  3  can be seen. Cover surface  33  has an outer, roughly flat region  34 , which is followed by a cover surface region  35  running inclined conically upwards. 
     Finally, a cover surface part directed cylindrically upwards then follows, having at the top a flat termination  37 . Molded on the inner side of this flat termination  37  is a sealing plug  38 , which comprises circumferential sealing beads  39  on its outer side. These sealing beads  39  on sealing plug  38  co-operate in the closed state of the closure with circumferential sealing ribs  24  in drinking spout  22 . The integrity guarantee element according to the invention comprises a plate  50 , which is part of jacket wall region  31 . This plate  50  is completely separated from jacket wall region  31  apart from lateral predetermined breaking point bridges  51  and upper predetermined breaking point bridge  52 . The two lateral predetermined breaking point bridges  51  form the connection between mentioned plate  50  and laterally adjacent jacket wall region  31  which is offset inwards with respect to edge  32 . A third upper predetermined breaking point bridge  52  forms the connection between mentioned plate  50  and flat cover surface part  34  of cover  3 . Preferably only three such predetermined breaking point bridges are present, but it is perfectly conceivable also to provide more than just three predetermined breaking point bridges, but which then have to be constituted thinner in order that the forces required for the first opening are kept within limits, in such a way that the user can open the closure without using excessive force. 
     A locking hook  53  is integrally molded on the outer side of plate  50  lying remote from the center. This locking hook engages, in the closed state of the closure, in a hook locking window  26  of first, outer apron  25  on lower part  2 . As described above, two such integrity guarantee elements are preferably present. Thus, as can be seen in  FIG. 2 , two plates  50  can be seen, which can engage with their externally fitted locking hooks  53  in two hook locking windows  26 . 
     The function of first, outer apron  25  is of course to form, in particular, a counterpart to separable plates  50  with locking hook  53  on cover  3 . First apron  25 , however, at the same time forms a screen in order to cover jacket wall region  31  of cover  3  that is offset towards the center. Windows  26  are constituted larger than the width and height of locking hooks  53 . The user thus still has a view of plate  50  or locking hook  53 . 
     Shorter apron  27  running closer to the center and concentric with the first apron has other functions. On the one hand, it serves to ensure that inwardly offset jacket wall region  31  is guided precisely into position during the mechanical first closing, and that locking hooks  53  on plates  50  are guided exactly in front of hook locking windows  26  and are displaced there to an extent such that locking hooks  53  engage through these hook locking windows  26 . At the same time, however, this inner apron prevents tampering with the integrity guarantee element. Plates  50  cannot therefore be shifted from the outside inwards, so that the locking hooks would no longer be engaged with the hook locking windows. The integrity guarantee element can therefore only be destroyed by the closure being opened, i.e. by cover  3  being rotated relative to lower part  2  about hinge  4 . When such a first opening is carried out, mentioned lateral predetermined breaking point bridges  51  and upper predetermined breaking point bridge  52  are destroyed and plate  50  is completely separated from jacket wall region  31  of cover  3  that is offset towards the center. Plates  50  thus separated remain captured between first, outer apron  25  and second, inner apron  27 . After the first opening, separated plates  50  are able to slip out laterally between the two aprons  25  and  27 . When the closure is closed again, cover  3  is held to lower part  2  by sealing plug  38  in drinking spout  22 . The view through hook locking windows  26  is now free. If the closure is produced in two colors by means of a coaxial mold, i.e. for example lower part  2  in green and the cover in orange, the orange-colored locking hooks  53  or plates  50  are seen before the first opening and, after the first opening, the green part of inner apron  27  is seen through the same hook locking windows, whereas the orange part of plate  50  is absent. 
     In order to enhance the drinking convenience of plastic closure  1 , a segment  6  of cover  3  is present above a film hinge  61 , which runs in the flat cover surface part and which separates segment  6  from the remaining cover with a swiveling motion. Jacket wall  30  of cover  3  accordingly comprises lateral slits  62  and, for reasons of hygiene, a partition wall  63  runs from first slit  62  to opposite-running slit  62 ′, said partition wall lying, in the closed state of the closure, at least approximately on the flat region of cover surface  21  of lower part  2 . This allows the user to swivel this cover part and the film hinge away from the spout by using his finger when drinking, so that the latter is not in the way during drinking. 
     Lower part  2  is also connected at the lower edge of jacket wall  20  to a securing ring  70  by means of securing ring predetermined breaking point bridges  71 . A support elevation  72  is provided between two adjacent securing ring predetermined breaking point bridges  71  in each case, and the securing point predetermined breaking point bridges  71  are longer than the support elevation  72 , which projects above the upper edge of the securing ring  70 . This securing ring  70  allows the closed closure to be easily pressed on a container. For this purpose, retaining beads pointing inwards are molded on the inner side, not visible in the drawing, said retaining beads being able to be engaged with a circumferential retaining bead on the container neck. This therefore also ensures that closure  1  cannot be removed in the closed state from the container neck and subsequently be emptied undetected. When predetermined breaking point bridges  70  are destroyed, securing ring  70  slips to a lower level and a purchaser thus clearly recognizes that the container has already been opened. 
     This detectability of the first opening can be improved still further by spraying plate  50  in a different color from the rest of the closure, or by the fact that lower part  2  is sprayed in one color and cover  3  in another color. This can also be achieved with a one-piece closure by means of so-called coaxial injection molding. 
     REFERENCE LIST 
     
         
           1  plastic closure 
           2  lower part 
           3  cover 
           4  hinge 
           6  segment of cover  3   
           40  hinge piece 
           41  film hinge 
           42  tension bands 
           20  jacket wall of lower part 
           21  cover surface of lower part 
           22  drinking spout 
           23  drinking opening 
           24  sealing lips in drinking spout 
           25  first apron 
           26  hook locking window 
           27  second inner apron 
           28  grip recess 
           30  jacket wall of cover 
           31  jacket wall region 
           32  edge of cover surface 
           33  cover surface of cover 
           34  flat cover surface part 
           35  cover surface region directed conically upwards 
           36  cylindrical cover surface part 
           37  flat termination 
           38  sealing plug 
           39  sealing beads 
           50  plate 
           51  lateral predetermined breaking point bridges 
           52  upper predetermined breaking point bridges 
           53  locking hook 
           61  film hinge 
           62  slits 
           70  securing ring 
           71  predetermined breaking point bridges