Abstract:
A closing device located on a container of laminated paper, over a predetermined opening. The device has a lower part with a pouring opening and a cover closing the opening. A push-piece for breaking open the predetermined opening is provided in the lower part. The push-piece is joined to the lower part by a snap hinge, making the device more user-friendly and ensuring that the laminated paper predetermined opening does not obstruct the pouring opening area.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a closure device for laminated paper containers, with the closure device arranged on the container over an opening of the container. 
     2. Description of Prior Art 
     Conventional containers of laminated paper have a cubic basic shape and are for packaging liquid products, in particular products of the food industry. The construction of the laminated papers used from the outside to the inside have the following layer sequence: polyethylene film; cardboard; polyethylene; aluminum layer; and polyethylene. 
     In this multi-layered material which is usually called laminated paper, with containers having a closure device, in the surface of the container in the laminated paper there is a predetermined opening. With the predetermined opening, a pre-cut opening normally has the upper three layers cut through, with the lower two layers of aluminum and polyethylene completely intact. 
     The closure devices are for containers of laminated paper which are known in two basic types. With an older type the container is already opened and the opening is sealed with a seal which can be pulled back. After removal of the seal the container is sealingly closed by the closure device attached onto the container. Accordingly, such closure device has a lower part with a pouring-out opening and a cover pivotally mounted thereon which closes the pouring-out opening with a sealed wall that sealingly engages into the pouring-out opening. 
     The seal is destroyed either by tearing open or by perforating or cutting, using a device which is arranged on the cover. This variation however requires the cover in a completely opened condition to be transported, stored and handled, by which there exists the danger of an undesired destruction of the seal. 
     Thus closure devices of a second type have been developed wherein the container of laminated paper is unopened and comprises only a predetermined opening. Such a predetermined opening may be of various types. Mostly several layers of the laminate are cut through and only the inner plastic layer and the aluminium layer lying thereover are still intact, as previously described. 
     The predetermined opening may have various forms, specifically one which is longitudinally separable and forms two tabs which may be laterally folded away from or of a single U-shaped tab which may be folded away to the rear. 
     Such predetermined openings must thus be pierced and cut open. For this purpose, for example, U.S. Pat. No. 4,934,590 shows a conventional closure device. 
     The closure device described here has, present in the lower part, a pivotal push-piece which serves for completely cutting open the predetermined opening and thereafter moving the corresponding U-shaped tab out of the pouring-out region to the rear. However, in the original position the push-piece which is to cut open the predetermined opening lies exposed and thus is completely unprotected against undesired or wanton destruction. The actual cover is simultaneously used as an actuation lever which in the original position is completely opened. At the same time, the surface of the cover coming to position into the container to the inside before closure for the first time is always exposed to contamination. For the mentioned reasons, such conventional closure device has not succeeded in the market. 
     The problem of keeping the tab from the region of the pouring-out opening has not been solved with known closure devices. The push-piece which is specifically positively and pivotally connected to the cover with this embodiment is then actually only pressed to the rear when the cover is closed. In this position, when the cover is completely opened the push-piece is completely freely pivotal and is moved forwards by the tab, because of the material elasticity, as when the container is relatively full, gets into the flow of the exiting contents by which means the pouring-out jet is interrupted. 
     SUMMARY OF THE INVENTION 
     One object of this invention is to provide a closure device of the mentioned type but without the known problem. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings show a preferred embodiment of this invention, wherein FIG. 1 shows and the subsequent FIGS. 2-7 vertical sections show the closure device attached on a suitable container of laminated paper, in various positions of use, wherein: 
     FIG. 1 shows a condition before the first use with a closed cover; 
     FIG. 2 shows the same condition shown in FIG. 1 but with an opened cover; 
     FIG. 3 shows a push-piece pushed in about up to an unstable equilibrium position; 
     FIG. 4 shows a lowest position of the push-piece; 
     FIG. 5 shows a permanent position of the push-piece after the first opening of the closure device; 
     FIG. 6 shows a section taken through the closure device in a position according to FIG. 1 but perpendicular to a longitudinal alignment; 
     FIG. 7 shows the closure device according to FIG. 2, in an enlarged scale; 
     FIG. 8 shows the closure device according to FIG. 2 in a plan view, wherein the closure device is shown attached on the container; 
     FIG. 9 shows a closed closure device in a view from below; and 
     FIG. 10 shows a plan view of the closure device. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     With reference to the FIGS. 7 to  10  the closure device  1  is explained in detail. With reference to the FIGS. 1 to  6  the invention and the use of the closure device  1  is explained. Principally, the closure device  1  comprises three large-surfaced main elements, specifically a lower part  2  to which there is attached a cover  4  via a joint axis  16 . The lower part  2  comprises a pouring-out opening  3  which is initially covered by a push-piece  5 . The lower part  2  has a circumferential, even adhesive edge  20  with which the closure device  1  is welded or adhered onto the container of so-called laminated paper. As initially mentioned the container comprises a predetermined opening which at least approximately coincides with the pouring-out opening  3  of the closure device  1  when the closure device  1  is attached to the container B, exact to location. The push-piece  5  has two parts, specifically a large pivoting part  9  and a small fastening part  8 . These two parts are connected to one another via a film hinge  10  and via a bending spring element  11 . Thus the film hinge  10  is interrupted in the region of the bending spring  11 . The predetermined opening in the container B must be at least as large as the pivoting part  10  of the push-piece  5 . Around the pouring-out opening  3  there runs a circumferential seal wall  7  folded up with respect to the adhesive edge  20  of the lower part  2 . With respect to the adhesive edge  20  of the lower part  2  the seal wall  7  is displaced concentrically inwards. In the rearwards region of the adhesive edge  20 , on its periphery, there is folded up an additional wall  21  on whose upper edge there is arranged the joint axis  16  for the hinging connection of the lower part  2  to the cover  4 . The cover  4  has a peripheral support wall  22  which in the closed condition of the closure device  1  is supported on the adhesive edge  20  of the lower part  2 . Thus it is ensured that a pressure on the cover  4  in the closed condition before the first opening of the closure device  1  may not exert pressure on the push-piece  5  and thus effect an undesired opening of the container B. Concentrically to the support wall  22  there is attached a complete circumferential sealing ring wall  14  on the lower side of the cover  4 . This is dimensioned to sealingly encompass the seal wall  7 . Accordingly the seal ring wall  14  at its edge directed inwards comprises a circumferential sealing bulge  17 . This acts in the closed condition of the closure device  1  in a circumferential sealing notch  18  by which means a high degree of seal may be achieved. 
     For supporting the push-piece  5  relative to the lower part  2  and as a guarantee element the push-piece  5  on its lower longitudinal edges is connected to the lower part  2  via predetermined breaking locations  19 . This lateral arrangement is preferred because onto the predetermined breaking location  19  there does not occur a tension loading but a shear loading, by which means the predetermnined breakage location  19  may be particularly easily manufactured. 
     The push-piece  5  which serves for breaking open the nominal opening in the container B is thus specially formed. From a preferably centrically arranged notch element  25  which is arranged diametrically opposite the film hinge  10  of the push-piece  5 , the push-piece  5  has a circumferential obliquely upwardly inclined edge  24  which finally blends into the cover surface  23  of the push-piece  5 . The edge  24  from the notch element  25  with a certain taper angle in the direction towards the cover surface  23 , at least in the front region of the push-piece  5  is formed as a cutting edge  26 . 
     Proceeding from FIG. 1 from now on the closure device  1  already described in detail will be explained in its various functional positions. In the representation according to FIG. 1, the closure device  1  is in the completely closed condition. The lower part  2  of the closure device  1  is fastened on the container B. The non-viewable predetermined opening is completely closed and the container is thus sealed. The push-piece  5  is fixed to the lower part  2  layer via the predetermined breaking locations  19 , and the cover  4  is closed and protects the push-piece  5  located thereunder. This situation corresponds to the transport position. With regard to plastic design as well as with other means additionally the cover  4  may be connected with respect to the lower part  2  via a guarantee element. In the simplest embodiment this may be a paper seal which at least partly overlaps the cover  4  and is connected to the container B. It is also possible at the projecting edge of the cover  4  via suitable predetermined breaking locations  19  to arrange a guarantee strip which is positively and/or non-positively connected to means, not shown, on the lower part  2  of the connection device. 
     The situation as is shown in FIG. 2 shows the first step of the first opening of the closure device  1  or the opening of the container B. The cover  4  is pivoted to the rear by 180°. Now the push-piece  5  is freely accessible and recognizable. This position has already been described in detail by way of FIG.  7 . 
     By way of pressure on the push-piece  5  the container B is opened. A first intermediate position is represented in FIG.  3 . With this the shaping of the push-piece  5  plays an important role. The predetermined opening in the container B may only be opened when the two still intact inner layers, specifically that of aluminum and the polyethylene layer lying innermost are first pierced and thereafter cut open. For this the push-piece  5  comprises the mentioned notch element  25  which is arranged at the end, lying opposite the film hinge  10 , of the push-piece  5 . With the notch element  25 , the aluminum layer as well as the polyethylene layer are pierced without a force effort. Thus it is ensured that the user with a pressure on the push-piece  5  does not press this jerk-like into the inside of the container and thus contact the contents of the container, or does not spill the contents from the container to the outside. The laterally arranged predetermined breakage locations  19  additionally lead to a particularly easy opening, since the predetermined breakage locations  19 , are not loaded with regard to tension but to shearing, by which means they may be easily destroyed. 
     Most push-pieces used today lie as a whole large surfaced themselves on the predetermined opening or have cutting edges which rest linearly over the predetermined opening on the intact layers. With a pressure on the push-piece, mostly an essentially tension force onto the foil takes place which must be relatively high before the two residual layers tear, so that again the push-piece  5  jerk-like immerses into the container with the already described unpleasant consequences. Attempts have also been made to arrange a centric cutting edge on the lower side of the push-piece which over the whole length has a certain taper angle. The height difference which with this is available is however so slight that because of the elasticity of the still intact polyethylene layer this deforms so far that again there is effected a complete linear resting. 
     According to this invention, the cutting edge  26  only in the front third of the push-piece  5  runs inclined relatively steeply up towards to cover surface  23 , while the lower part, extending towards the film hinge  10 , of the cutting edge, runs roughly parallel to the cover surface  23  of the press piece or even runs retrograde again in the direction towards the base surface of the lower part  2 . Thus the cutting edge  26  may exert as optimal as possible shearing effect on the layers lying thereunder. The reduction of the inclination of the cutting edge  26  on the push-piece to the front third of the push-piece is based on the recognition that with the now applied pivoting movement the required cutting angle alone already by way of the relative position of the push-piece to the horizontal cutting surface leads to an optimal shearing angle. The negative inclination angle, of the cutting edge  26 , which is present in the rear region of the push-piece near to the pivoting axis and is formed by the film hinge  26  by the large angle change of the push-piece itself again leads to an optimal cutting angle. 
     The position of the push-piece  5  of FIG. 3 corresponds at least approximately to the dead center position of the snap hinge  6 . This angle may be optimally designed by way of a suitable formation of the bending spring element  11  and of the relative arrangement of the film hinge  10  as well as of the linkage locations of the bending spring element  11 . Already with an immersing angle of about 35° the dead center position of the snap hinge may be achieved so that the push-piece  5  automatically moves further away from here under the effect of force of the bending spring element  11 . With this it brushes over the lowest position, as is shown in FIG. 4, in order to remain in an end position rotated maximally by 180°. The push-piece  5  with its pivoting movement pushes the tab L, which previously had covered the predetermined opening, in front of it and finally presses the tab in the end position according to FIG. 5, at least approximately from below onto the cover surface of the container B. In this position the tab L remains held so that neither it nor the push-piece  5  itself may pivot back into the region of the pouring-out opening  3  and by way of this disturbs the pouring-out stream. 
     Finally then the cover  4  may again be closed using the sealing ring wall  14  on the lower cover surface of the cover  4 . Until now it was usual for the sealing ring wall  14  to sealingly bear on the inner edge of the pouring-out opening  3 . Accordingly, remains of fluid remained on the sealing wall  7  of the lower part remained covered by the cover but not circumferentially protected. Accordingly these pouring-out remains led to contamination, crystallization or oxidation and influenced the quality of the material to be subsequently poured out and led to aesthetically completely unsatisfactory results. Accordingly it is desirable to dimension the sealing ring wall  14  on the cover  4  such that it may encompass the sealing wall  7  on the lower part from the outside. Thus the whole region which contacts the fluid lies within the closed space in which at least approximately there prevails saturated vapor pressure, by which means it is prevented that the residual quantities crystallize out and further these residual quantities may thus flow back into the container B. Also an increased seal may be achieved. With this formation, specifically, the sealing ring wall  14  without problem may be provided with one or more annular sealing bulges  17  and accordingly the sealing wall  7  on the lower part  2  on the outside may be circumferentially provided with sealing notches  18 . This also leads to an improved holding force of the cover  4  on the lower part  2 . In order to optimally design this solution as mentioned in the rear region on the adhesive strip  20  there is attached an additional rearward wall  21  on whose upper edge there is located the joint  16  about which pivots the cover  4 . Thus the sealing annular wall  14  may be completely circumferential just as the sealing wall  7  on the lower part by which means the closure device  1  optimally and securely closes the pouring-out opening  3 .