Patent Publication Number: US-6902078-B2

Title: Cans for carbonated and non-carbonated beverages, closure systems for them and method to open the cans

Description:
This invention broadly relates to cans for supplying carbonated and non-carbonated beverages and more particularly it concerns some improvements to enable not only the opening operations of the cans to be more effectively carried out, but also to solve the two main problems raised by popular diffusion of this type of beverage containers. 
   As it is known, the cans are presently the most popular means for retail sale of various beverages, in view of the transport ease as well as of the low manufacturing cost of them. Such containers are realised by a thin metal plate and are distributed on sale in tightly closed condition, so that opening thereof requires tearing of a portion of the wall of the container itself, usually at its upper surface, by means of a tongue that is provided with a slight score line aimed at aiding its tearing and with a small ring attached to the tearing tongue. 
   As the use of containers of this type became more and more popular, a problem of hygienic character was raised due to the fact that, after their manufacture and after filling or even during their shipping to the various distribution stations, such cans are usually maintained in stores that do not offer any hygienic or safety guarantee. When one considers that very rarely such cans can be washed before opening and that sometimes, after opening, they are brought in direct contact with the mouth of the consumer for drinking the content, it can be understood that the consumer runs a high risk of infection. 
   A first aspect of this invention, therefore, is to guarantee an hygienic use of the cans. 
   Since, together with the well known plastic bags, such cans represent a product that causes a noticeable contribute to environment contamination in view of their diffusion, particularly in connection with their opening tongue that, upon detaching thereof, is usually left lying around, a second aspect of this invention is to provide an opening system that does not entail the possibility to free and to detach tongues amenable to be abandoned also in potentially dangerous places, such as the sand of a beach, where they remain at hand of each child unaware of the danger. 
   With reference to this aspect, a subordinate problem, which is raised regardless of the fact that such tongues are disadvantageously realised with detachable construction, is due to the fact that such opening tongues, as above mentioned, are opened by a tearing operation aided by a slight score cut in the thickness of the can thin plate in the area of the can cover. This entails that the edge of the torn tongue as well as the edge of the aperture left in the cover after removal of the tongue unavoidably have tiny burrs that are very sharp. Even if this consequence can be of scarce relevance in respect of the can cover aperture, it can be extremely dangerous in respect of the tongue itself, that, upon detachment from the can, is to be considered as a sharp cutting and very dangerous waste item. 
   All these issues are addressed by Italian Utility Design Application No. RM99U000099, filed on May 7, 1999, by the same Applicant that, in its preferred embodiment, comprises a can for carbonated and non-carbonated beverages provided with an opening system comprising an opening device with a tearable tongue defined by a tearing invitation score line in the outer surface of the upper wall of the can and with a tearing device associated to said tearable tongue and aimed at tearing said tearable tongue and at opening the can, wherein said tearing device for the tearable tongue includes a second additional tongue, integrally connected to said tearable tongue and unremovably fixed to said can, so as to avoid that both said tongues be detached from the can, said additional tongue has a shape corresponding to the shape of said tearable tongue and slightly larger perimetral dimensions, in order to cover the possibly sharp tearing edges of said tearable tongue. 
   It has been found that a closure device for cans as disclosed in the above mentioned patent application has some drawbacks due to the difficulty to carry out tearing of said tearable tongue without realizing a preliminary score line to aid starting the tearing action. 
   It is a specific object of this invention to provide a closure structure for cans wherein said drawback is overcome and opening of the can is performed by suitably starting the tearing action on the tearable tongue. 
   This object is achieved by means of an opening system for cans wherein the tearing device for tearing said tearable tongue is comprised of two tongues superimposed to one another, a first tongue attached to the outer surface of the upper wall of the can, intended to tear said tearable tongue outwardly of said can, and a second tongue, attached to said tearable tongue, intended to start tearing of said tearable tongue inwardly of the can. 

   
     Further particulars and advantages as well as characteristics and construction details will be evident from the following description with reference to enclosed drawings wherein the preferred embodiment is shown by way of illustration and not by way of limitation. 
     In the drawings: 
       FIG. 1  shows a plan upper view of a system for opening the tearable tongue according to the above mentioned Utility Design Application, 
       FIG. 2  shows a partial cross-section view taken along line II—II of  FIG. 1 , 
       FIG. 3  shows a plan upper view of the can of  FIG. 1  in open condition, 
       FIG. 4  shows a partial cross-section view taken along line IV—IV of  FIG. 3 , 
       FIG. 5  shows a plan upper view of a can with an opening system for the tearable tongue similar to the one shown in  FIGS. 1-4 , 
       FIG. 6  shows an upper plan view of a can having a tearable tongue scored in its upper wall according to this invention, 
       FIG. 7  shows an upper plan view of a ring like tearing tongue designed for attachment to the can of  FIG. 6 , 
       FIG. 8  shows an upper plan view of a ring like tongue intended to start tearing of the tearable tongue from the can of  FIG. 6 , 
       FIG. 9  shows an upper plan view of the can of  FIG. 6  after the ring like tearing tongue shown in  FIG. 7  has been attached, 
       FIG. 10  shows an upper plan view of the can of  FIG. 6 , in finished condition, after both ring like tongues of  FIGS. 7 and 8  have been attached, and 
       FIG. 11  shows an axial cross-section view of the can of  FIG. 10  in closed condition, 
       FIG. 12  shows an axial cross-section view of the can of  FIG. 10  in a position in which the tearing starting tongue is operated, 
       FIG. 13  shows an axial cross-section view of the can of  FIG. 10  in the opening condition, after both the tearing starting ring like tongue of FIG.  8  and the tearing ring like tongue of  FIG. 7  have been operated. 
   

   By referring now to  FIGS. 1-4  of the annexed drawings, it can be observed that the construction disclosed in the above mentioned Utility Design Application is shown by way of illustration, as an attempt to solve the above discussed problems of the environment prejudice and of the dangers connected with the sharp edge of the tearable tongue in conventional cans. 
   It has been stressed that, aiming at preventing that, upon opening the can, the tearable tongue be unproperly abandoned and become not only a danger, but also an environment contamination, even assuring that the can is excellently open, it is necessary that the tongue is not detached from the can and it is not left lying around. 
   Furthermore, as above said, should even the tongue be completely detached and even more should it be left attached to the can, it is absolutely necessary that all unavoidable tiny and sharply cutting burrs formed by the tearing action do not represent a cutting danger for the hands and even more for the mouth of all those consumers who, regardless of any aesthetic consideration, wish to use the opened can as a drinking glass. 
   By specifically referring to  FIGS. 1-4 , it can be observed that a second additional tongue  23  is superimposed and attached upon said first tearable tongue  22 , scored on the upper surface of the can, said second tongue  23  being characterised in that it is unremovably attached to the can and in that it has perimetral dimensions slightly larger than the dimensions of the tearable tongue  22 . 
   In  FIG. 1 , the tearable tongue  22  is shown in dashed line and it is completely removable, so as to completely open a hole  24  as illustrated in  FIGS. 3 and 4 , for accessing the beverage contained in the can. 
   In  FIG. 5 , the tearable tongue  25  is again shown in dashed line, but it is not completely removable: it can be only partially raised, because it is realised by a partial score line in the upper surface of the can. In any case, it has dimensions smaller than the dimensions of the superimposed or additional tongue  26 , which is anyway unremovably attached to the can. 
   The rigid connection between the two tongues is realised by means of a technique selected among spot welding, line welding, pressure or cold upsetting, thermocompression or glueing, so as to guarantee in any case a suitable tearing of the tearable tongue. 
   In this structure, two essential characteristics are to be remarked because two completely novel and advantageous effects can be obtained therefrom. 
   In the first place, when the can is opened, the tearable tongue  22  or  25  is never completely detached from the can, in view of the fact that it remains affixed to the additional tongue  23  or  26  which, in turn, is unremovably attached to the can. By this means, it is possible to eliminate the risk that the tearable tongue is completely detached and left lying around. 
   In the second place, since the tearable tongue has dimensions smaller than the dimensions of the additional tongue, all sharp edges caused by the tearing action thereof are always located inwardly with respect to the edges of the additional tongue which are blunt and not dangerous and, therefore, such sharp and cutting edges are covered and “protected”, thereby eliminating any risk that the users of the can be accidentally injured. 
   Aiming at overcoming any possible difficulties on starting the tearing action of said tearable tongue, this invention proposes a solution as shown in  FIGS. 6-12 . 
   By referring to  FIG. 6 , it can be observed that the upper wall of the concerned can has a tongue  22  scored or partially cut through the thickness of the wall and consequently tearable from said wall. Such tongue is strictly similar to the tearable tongue of  FIGS. 1  to  5  and, therefore, it can be partially or completely removed from the can wall. Broadly it has an elongated shape with an end apex point at which the tearing action to open the can could be most easily started. 
   According to this invention, the opening system for the can, namely, in effect, the system for tearing and lifting said tongue  22 , comprises the combination of two ring like tongues, one of which, namely  31 , as shown in  FIG. 8 , is designed to start tearing of the tearable tongue  22  inwardly of the can, while the other one, namely tongue  30 , as shown in  FIG. 7 , is designed to prosecute tearing of said tearable tongue  22  in opposite direction, outwardly of the can. 
   The tearing tongue  30  of  FIG. 7  has a ring like elongated shape, with a hole  33  having a profile corresponding to the shape of the tearable tongue  22  scored in the outer surface of the upper wall of the can and two side segments. Tearing tongue  30  can be attached to the upper wall of the can at a point  32  by means of any one of the well known systems as mentioned in the previous patent application. The outer dimensions of this tearing tongue are larger than the outer dimensions of said tearable tongue  22 , so as to protect the user against any contact with its outer sharp edge. 
   The tearing starting tongue  31  as shown in  FIG. 8  has a ring like shape, with two tabs  34  and  35  that can be overlaid to the side segments of said tearing tongue  30  of  FIG. 7 , as well as a beak point portion  36  adapted to act upon the front edge of the tearable tongue  22  scored in the outer surface of the upper wall of the can. Said tongue  31  can be attached to the upper wall of the can at a point  37 , at a position approximately corresponding to said two tabs  34  and  35 , by means of any one of the systems mentioned in the previous patent application. 
   The logic order for assembling the two tabs system provides for the tearing tongue  30  to be attached to the upper wall of the can at point  32  and for the tearing starting tongue  31  to be applied upon the tearing tongue and to be attached to upper wall of the can at point  37 . This arrangement is substantially illustrated in the cross-section view of FIG.  11 . 
   As it can be observed, the attachment point  37  of tongue  31  to the can is aligned with and intermediate between the ring like portion and its beak point portion  36 . Therefore, the combination of said two tabs  34  and  35  acting on the side segments of the underlying tongue  30  and of said attachment point  37  forms the fulcrum of a centrally fulcrumed lever. 
   When the opening procedure is started by lifting the ring like portion of said tearing starting tongue  31  and by rotating the tongue from the center point outwardly, from the center to the periphery, its front beak like point portion  36  pushes the tearable tongue  22  scored in the upper wall of the can inwardly and, therefore, it starts tearing thereof. Upon starting the tearing, the tearing tongue  30  can be utilized, by acting inwardly from the periphery to the center, in order to complete tearing of the tearable tongue  22  and opening of the can. The open condition is shown in the cross-section view of FIG.  12 . 
   From an operational and functional view point, it should be underlined that, in view of its function as a tearing starting member, it is convenient that the material of said tongue  31  be more rigid and mechanically stronger than the material of said tongue  30 , which is only designed to prosecute tearing of the tearable tongue  22 , as already started by said tearing starting tongue  31 . 
   From the above, it is apparent that, for the discussed steps of starting and completing the tearing of the tearable tongue  22  to be successfully carried out, it is very important that the end apex point of the tearable tongue  22 , the attachment point  37  of the tearing starting tongue  31  and the attachment point  32  of said tearing tongue  30  be aligned and that said attachment point  37  be intermediate between said apex point of the tearable tongue  22  and said attachment point  32  of the tearing tongue  30 . 
   As above mentioned, the illustrated assembling order is only a logic order, but it is not necessarily a time order, which means that the two tongues  30  and  31  can also be previously assembled together, by attaching the two side tabs  34  and  35  of tongue  31  to the side segments of tongue  30  and thereafter by attaching the combination of said tongues  30  and  31  to the surface of the upper wall of the can at the two attachment points  32  and  37 . 
   Furthermore, particularly in connection with the illustrations of  FIGS. 11 ,  12  and  13 , it should be understood that they are purely illustrative and schematic, so that they do not illustrate exact thicknesses and exact height relationships and exact spatial superposition of the thicknesses, since these details can be perfectly designed by those skilled in the art. 
   A further advantage of the construction as above described and illustrated is that, upon opening the can by operating tongues  30  and  31  in the already explained way, it is possible to again close the can, even if in not tight manner, by inversely bending the concerned two tongues  30  and  31  and, consequently, the tearable tongue  22 , so as to at least cover the hole formed in the upper wall of the can. 
   The preferred embodiments of this invention have been described and a number of variations have been suggested hereinbefore, but it should expressly be understood that those skilled in the art can make other variations and changes to the details and to the construction particulars and can exploit all construction and operation features as above described and as shown in the enclosed drawings, individually or in any combination thereof, without so departing from the scope of this invention.