Abstract:
A method and apparatus for packing, opening a soda can, for protecting the contents from contaminants during storage and shipping, the area on the container side covered by a cap being provided with an undercut zone, and elements being provided inside the twist-off cap for rupturing the undercut zone as the cap is rotated, the container presently beneath the cap opening along the undercut zone.

Description:
RELATED APPLICATION  
       [0001]     This application claims priority of Finnish Patent Application No. 20045373 filed Oct. 5, 2004.  
       FIELD OF THE INVENTION  
       [0002]     The invention relates to an apparatus and method for hermetically packing a foodstuff or a refreshment beverage, for opening and closing a can. The apparatus and method enable opening a can and, after a partial ingestion of contents, protecting the contents from external contaminants. The pouring and drinking lip of an unopened can, as well as the openable cap of a container shall be protected from ambient contaminants during shipping and storage.  
       BACKGROUND OF THE INVENTION  
       [0003]     Commonly used beverage cans of aluminium are opened, after filling a can preform, by means of a press lever, which is flush-riveted to a cap sealed with a lap joint in a waterproof and airtight manner to its top end. The opening lever is pulled upwards e.g. with a fingertip, the other end of the lever pressing inwards a cutout blank punched in the cap for opening the can. The contents can be ingested or poured out from the opened hole. The same method is applied for opening containers of solid canned foods. Thus, almost the entire cap of a food can may open along the punchline.  
         [0004]     Notable drawbacks in the lever method include the difficulty of taking a hold of the lever, the task being often a nuisance for small children or rheumatic people: a fingernail may be damaged in the opening effort, fingers do not always have a sufficient strength. The cap of an unopened can is exposed to ambient dust and contaminants. It is doubtful whether any study has ever been conducted regarding impurities and disease carriers accumulated on the cap during storage and shipping, which, particularly in the case of a beverage can, are flushed into the internal organs along with the beverage. Attempts have been made to eliminate the problem by providing a separate removable closure, but with a poor success because the removable closure is quite often out of reach. Drinking straight from the can is inconvenient because the pouring hole e.g. in soda cans has a small mouth and the outflow of a beverage causes abundant bubbling due to the fact that there is no intake for replacement air in the can. The cap of a can collides with the drinker&#39;s nose and the natural human instinct of thirst is not fully satisfied as the freshness or contamination of a beverage cannot be ascertained by the olfactory sense.  
       SUMMARY OF THE PRESENT INVENTION  
       [0005]     It is an object of this invention to facilitate the opening of a hermetically packed can of food, beverage or the like, to protect the contents of an opened can during extended storage from becoming flat and against ambient contaminants. To eliminate a possibility for contaminants and disease carriers gathered on the cap during shipping and storage of migrating into the internal organs of a drinker. To eliminate bubbling, to improve the pourability and drinkability of a beverage straight from the can, to enable the olfactory sense to ascertain the freshness and drinkability of a beverage prior to drinking straight from the can.  
         [0006]     In order to overcome the drawbacks and to accomplish the benefits described above, a method and an apparatus of the invention are characterized by what is stated in the characterizing clauses of independent claims  1  and  7 . The dependent claims disclose a few preferred embodiments. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The invention will now be described in detail with reference to the accompanying drawings.  
         [0008]      FIG. 1  shows a can of the invention in a side view.  
         [0009]      FIG. 2  shows a can of the invention in a plan view, without a twist-off cap.  
         [0010]      FIG. 3  shows just a twist-off cap in a side view.  
         [0011]      FIG. 4  shows a can according to a second embodiment in cross-section.  
         [0012]      FIG. 5  shows the can of  FIG. 4  in a plan view.  
         [0013]      FIG. 6  shows a cap for the can of  FIG. 4-5  when removed.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]     As shown in  FIGS. 1-3 , the can comprises a body  1 , a twist-off cap  4 , and a detachable bottom S. The twist-off cap  4  is secured by flush-riveting centrally to a container blank&#39;s bottom  5  produced in the deep drawing stage of a can. Around the periphery of a container blank is provided a cut-off point with a punched line  3 , and the container blank is provided with an indent  6  pressed towards the centre in compliance with a pusher  7 , included in the twist-off cap  4  and functioning as an opening tool. The can has its detachable bottom  8  secured to the body  1  with a multiple lap joint  9  in a waterproof manner after a filling process. The can has its label printed to read in a right way when the detachable bottom  8  is directed downwards, the cut-off line  3  thus being in the can&#39;s top portion. The indent  6  is preferably, for example, in the shape of a hemisphere, in which case the pusher  7  comprises preferably a quarter of the spherical surface, which contains an upper segment or a lower segment of the hemisphere.  
         [0015]     The can shown in  FIGS. 4-6  is a modification of the above solution. It has a skirt  10  around the container blank&#39;s bottom, said skirt  10  having its inner rim punched for a groove  3  along the cut-off line. As opposed to the above embodiment depicted in  FIGS. 1-3 , this protects the lips of a drinker as the cut-off groove is protected by the skirt when drinking. In addition, the skirt provides bracing to the lip of an opened can, the lip&#39;s stiffness being definitely more important than that of the rest of the can with regard to quality perception experienced by the consumer. In order to remove the cap of a can in opened condition from the can, the skirt  10  must have its inner rim  11  in conical shape, i.e. the inner rim must diverge outward. The skirt is pressed by a pusher  7 , thus expanding the opening and the container blank&#39;s bottom, functioning as a cap, being removable along with the twist-off cap. A proper conicity is at least 3-6 degrees from vertical line. The groove of a cut-off line can also be made inside the skirt  10 , in which case the cut-off groove is located in the flat section of a deep drawing blank&#39;s bottom  5  functioning as a cap.  
         [0016]     The can is opened by turning the twist-off cap  4 , which is flush-riveted centrally to the body of a can preform, to the right or left relative to the body, whereby the pusher  7 , pressed therein, ruptures the line  3  of a cut-off blank and both riveting-jointed elements  3  and  4  can now be removed from the top end of a can. The contents can be ingested from the open container, the freshness and flavours of a beverage being first perceived by the olfactory sense. The removed double cap  4 ,  5  has also protected the drinking lip from ambient contaminants and, if necessary, constitutes a dish that can be used as a drinking cup. The cap can be reinstated for protecting the remaining beverage from contaminants and from getting flat.  
         [0017]     The removable double cap and the can are both aluminum, and both parts can be recycled easily in the same process. The double cap can be put back on the can and the recycling machine can read the bar code from both cap and can, so that the return deposit can be checked for both parts.  
         [0018]     The inventive method and apparatus for opening and closing a can are not limited solely to the exemplified embodiment, but a wide range of variations are conceivable for many different containers of various substances.  
         [0019]     The same double cap can be used for opening also the other end of a preserve can containing a solid substance, or even for slicing an entire can, provided that a plurality of cut-off lines are punched in the cylindrical surface of the can, in which case there is an indent  6  reserved for a pusher  7  at every cut-off point, said indent possibly comprising a continuous vertical groove along the side of a can, or the can may be polygonal, in which case the vertical groove is constituted by a side of the polygon. In any event, it should be appreciated that the invention and method have only been described above in reference to one of its advantageous exemplary embodiments and this should by no means limit the invention to this single example as a multitude of modifications are feasible according to an inventive concept as defined in the following claims. For example, a cardboard-made container can be provided with a sharp cutting cap pusher  7  and even 200-liter barrels can be likewise equipped with a similar opening-closing mechanism. The double cap  4 ,  5  and the cylindrical body  1  of a can may be provided with a multi-terminal screw-thread for tightening the double cap in view of protecting the can after opening. It is also possible that the twist-off cap  4  be flush-riveted slightly off-center relative to the bottom  5  of a container blank.  
         [0020]     The opening line  3 , the pusher  7  and the indent  6  can also be located in the bottom  5  of a container blank. The bottom  5  of a container blank may also be concave, the twist-off cap  4  being correspondingly concave, or, in case the twist-off cap  4  is straight, there is a countersinking deep drawn in the twist-off cap  4  for a flush rivet, such that the deep drawing has its bottom reaching the surface of a container blank&#39;s concave bottom  5 .  
         [0021]     The twist-off cap  4  may also function without the flush rivet  2 , the twist-off cap having its rim bearing solely against the sides of a container. Thus, the container must be braced with an appropriate pattern for not allowing a flexing of the cap during a twisting procedure. The lap joint  9  may also function as a clamping or bracing element. Hence, the twist-off cap  4  settles preferably on top of the detachable cap  8  instead of the deep-drawn opposite end. In this case, the twist-off cap can be made for example in plastics and it may clamp to the lip of a container by means of flexible clasps, for example. The cap may also constitute a separate opening tool, but in that case many of the benefits offered by the invention cannot be attained for the reason that the container shall not have its exterior protected from dirt under the cap during transport and a separate tool is easily misplaced. When the opening of several disposable drinking containers is effected by means of the same opening tool without washing it between procedures, the resulting hygiene will be poorer than in the case of a disposable twist-off cap.  
         [0022]     In case of a conically shaped container, the cap can be depressible and, thus, some of the rupturing may occur solely as a result of depressing. In this case, the rupturing means are spaced from the undercut area prior to pressing in the cap for an opening process.