Patent Publication Number: US-7210592-B1

Title: Easy-to-open covers

Description:
FIELD OF THE INVENTION 
   The invention relates to overcapping covers of bottles of sparkling wine, typically champagne, and in particular covers provided with easy-to-open means. 
   BACKGROUND ART 
   So-called easy-to-open covers, such as those in  FIGS. 1 to 5 , are already known. Typically there are two types of covers: those with a tear strip often called a “Tircell” shown in  FIGS. 1 to 3 , and those with a single or double dashed or dotted line of weakness shown in  FIGS. 4 to 5 . 
   PROBLEMS POSED 
   The easy-to-open systems that have been proposed previously pose a certain number of problems described below, irrespective of the system used. 
   As explained above the covers are applied typically to champagne bottles and they play a considerable role in the decorative aspect of the bottles and improve their appearance. 
   When consumers open the cover either by pulling on the Tircell strip or cutting the cover along the dashed or dotted lines they invariably either fold or accidentally tear the cover. This is because the covers are made of relatively thin sheets or films and the covers are not necessarily torn along the intended lines of weakness that are traced out in advance. The tearing may thus lead an unattractive appearance that is totally random. 
   Sparkling wines are also put into bottles that are often provided with cork wire that ensures the cork remains in place and the bottle remains sealed even in the event of excess pressure being applied. It is therefore necessary for the cover to free the cork and cork wire (if present) when it is removed. 
   In other words an easy-to-open cover is required that overcomes all these drawbacks. 
   AIM OF THE INVENTION 
   The invention relates to a cover that enables the user to remove its upper part, which is that covering said cork wire, in a single movement without damaging any of the lower part covering the section of the neck of the bottle beneath the cork wire, such that the maximum quantity of cover remains on the bottle in its attractive, undamaged condition while enabling the cork to be removed. 
   DESCRIPTION OF THE INVENTION 
   According to the invention the easy-to-open overcapping cover  1 , which is typically conical, comprises a head  5  and a skirt  4  of a film or sheet material, typically for a recipient or bottle of sparkling wine  2  sealed with a cork  8  with a head  80  with means for fastening the cork to the neck of said recipient, typically a metal cork wire  3  provided with a tightening wire  30  that goes under the glass ring  20  of the neck of said bottle and constitutes an opening twist or loop  31 , or possibly for a recipient or bottle of still wine comprising easy-to-open means, typically a line of weakness, on the skirt of said cover, and is characterized in that: 
   a) said easy-to-open means comprise at least one so-called line of weakness  44 , described as being lower, located on the cover at a height H that defines a partition of said cover with a so-called upper part  10  and a so-called lower part  11 ; the height is such that after said cover and said recipient or sealed bottle have been assembled said line of weakness  44  breaks when said recipient or said bottle is first opened to provide access to said cork or possibly said cork wire once said upper part  10  has been removed, said lower part  11  remaining intact on the neck, 
   b) said upper part  10  comprises a gripping tab  46  the upper and lower ends of which include notches or recesses  460 ,  461  intended to direct the tearing of a tear strip  45  during said first opening, 
   c) said cover comprises at least one additional means selected from one of the following: a second so-called upper line of weakness  43  in said upper part  10 , means  67  for reinforcing all or part of said lower part  11 , means  66  for fastening all or part of said lower part  11  to the neck, means for reinforcing all or part of said upper part  10  such that when said recipient or bottle is opened for said first time said tear strip  45 , which is created by pulling on gripping tab  46 , removes the whole of said upper part  10  along with it, the lower edge of said strip being constituted when said line of weakness  44  breaks. 
   Height H is typically between 15 and 50 mm for recipients or bottles of sparkling wine and between 5 and 25 mm for recipients or bottles of still wine. 
   When covers are intended to overcap recipients or bottles of sparkling wine said fastening means may also consist of a staple hooked under the glass ring of the neck or a threaded cap that operates in conjunction with a threaded ring. 
   When the fastening means comprise a cork wire provided with an opening twist the line of weakness should be located at such a height that when the cover is applied to said neck it is slightly below the opening twist under the glass ring. 
   The situation is similar when the fastening means comprise a staple because the ends of the staple, similarly to the opening twist, hook under the glass ring that constitutes a contracted circular section. 
   The fastening means may consist of a threaded glass ring that operates in conjunction with a cap with a threaded skirt. In this configuration the line of weakness is located just below the lower end of said threaded skirt. 
   Tests performed on covers of the invention and the background art have shown clearly the benefits of combining the means described above in a), b) and c). The applicant has therefore taken advantage of these means to realize the aim in question, i.e. to remove the entire upper part of the cover in a single movement by pulling between the thumb and index finger of one hand while the other holds the bottle without damaging the lower part of the cover and decoration. 
   The cover of the invention therefore enables the cover to be opened correctly under “standard” opening conditions. “Opened correctly” implies removing the upper part of the cover while leaving the lower part intact, with a dividing line between the two parts that is typically a circle, such that the neck of the bottle remains covered with the lower part of the cover and said cover remains attractive. 
   Tests performed on covers of the invention and the background art have shown clearly that the invention alone enables the cover to be removed correctly and repeatedly without the consumer having to be particularly careful when opening the cover, as is usually the case. 
   It is important to realize how covers behave when they are opened under “standard” conditions which are typically in social occasions when the person opening the bottle is talking to somebody or in any event is not particularly looking at the cover of the bottle to be opened. 
   It is under these “standard” conditions that the cover of the invention is of particular interest. Covers of the background art are only opened correctly provided the “Tircell” or the tear strip is pulled in a direction that always remains perpendicular to the axis of the bottle. This is only possible if great care is taken otherwise the “Tircell” does not follow the tear lines and the part of the skirt is torn that should not be or the upper part of the skirt is not correctly torn to reveal the cork wire. The problem is therefore resolved by the combination of the means described in a), b) and c). 

   
     DESCRIPTION OF THE FIGURES 
       FIGS. 1 to 5  are partial lateral views of covers  1  of the background art obtained by rolling an arc of a skirt and bonding axial edges  60 ,  61  and showing various easy-to-open means located on skirt  4 . 
     In  FIGS. 1 to 3  the easy-to-open means are “Tircell” strips  41  one end of which is oriented in a more or less sloping direction. 
     In  FIG. 4  the means is a double line of weakness  42  and in  FIG. 5  a single line  40 . 
     In principle these means enable upper part  10  of cover  1  to be removed and leave lower part  11  on the bottle. 
       FIG. 6  is a side view of a conical cover  1  according to a embodiment of the invention. 
       FIGS. 6   a  and  6   b  relate to the upper part of covers  1  that constitute overcapping caps for bottles  2  of still wines sealed with a cork stopper.  FIG. 6   a  is a schematic cross-section along the vertical axis and  FIG. 6   b  is a perspective side view in which opening tab  46  is shown positioned between the upper 43 and lower 44 lines of weakness, said lower line of weakness being located on glass ring  20  of bottle  2 , skirt  4  of the cover being crimped under glass ring  20 . 
       FIG. 7  is a side view of a neck  7  of a bottle provided with a cover  1  of the invention where tab  46  is shown in the unfolded position ready to be gripped by the consumer, the tab before the cover is opened being folded back and flat against the cover as shown by the dotted line in the figure such that it does not extend beyond the rest of the cover and risk being pulled accidentally. 
       FIG. 8  is a similar side view to that of  FIG. 7  once the consumer has pulled tab  46  to create opening strip  45  and thus revealed cork wire  3  comprising a tightening wire  30  that goes under the glass ring and a tightening loop  31 . 
       FIG. 9  shows the result obtained after said cover has been opened easily, upper part  10  of the cover comprising head  5  remaining fastened to opening strip  46 . 
       FIG. 10  is a cross-section view of neck  7  of a bottle  2  showing the result obtained after the upper part of cover  10  has been removed, with a cork wire  3  covering a cork  8  and holding it in position with a tightening wire  30  that goes under glass ring  20  of the neck of the bottle, and with a lower part  11  of cover  1  held in place on neck  7 . 
       FIGS. 11   a  and  11   b  show top views of the inner surface of two arcs  6  of height H′ of conical skirt  4  of the cover consisting of a film or sheet material the outer surface of which is generally printed or decorated, used to produce said cover and including:
         two upper 43 and lower 44 lines of weakness ending in notches  460 ,  461  along the axial edge  60  that constitutes the upper edge after said arc has been rolled, and a checkered tab  46 , lower line of weakness  44  defining an upper part  69  and a lower part  65  of height H″,   a line of adhesive  63  along the other axial edge  61 ,   an upper rim  64  to which the head of the cap is fastened,   and, in the configuration in  FIG. 11   a , a fraction of said lower part  65  the inner surface of which is coated with an annular adhesive layer  66  of height H 1  that is activated when the cover is positioned on the neck, said layer being represented in  FIG. 11  and following figures by vertical hatching.       
       FIGS. 12   a  to  15   b , which are similar to  FIGS. 11   a  and  11   b , show other embodiments of the invention. 
     In these figures the adhesive layers on lower part  66  are shown by vertical hatching, strengthening layers  67  are shown by horizontal hatching and the superimposition of a reinforcement and an adhesive layer  68  is shown by crossed hatching. 
     Therefore: 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Upper part 69 
                 Lower part 65 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 FIG. 12a: 
                 reinforcement 47 
                 adhesive layer 66 
               
               
                   
                   
                 of height H 2   
                 of height H 1   
               
               
                   
                 FIG. 12b 
                 strengthening 
                 adhesive layer 66 
               
               
                   
                   
                 strip 48 
                 of height H 1  on 
               
               
                   
                   
                   
                 bonded 
               
               
                   
                   
                   
                 reinforcement 67 
               
               
                   
                   
                   
                 of height H 3   
               
               
                   
                 FIG. 13a 
                 reinforcement 47 
                 adhesive layer 66 
               
               
                   
                   
                 of height H 2  with 
                 of height H 1   
               
               
                   
                   
                 H 2  = L 
               
               
                   
                 FIG. 13b 
                 reinforcement 47 
                 adhesive layer 66 
               
               
                   
                   
                 of increasing 
                 of height H 1   
               
               
                   
                   
                 height H 2   
               
               
                   
                 FIG. 14a 
                 no reinforcement 
                 adhesive 
               
               
                   
                   
                   
                 reinforcement 68 
               
               
                   
                   
                   
                 of height H 1   
               
               
                   
                 FIG. 14b 
                 strengthening 
                 bonded 
               
               
                   
                   
                 strip 48 
                 reinforcement 67 
               
               
                   
                   
                   
                 of height H 3   
               
               
                   
                 FIG. 15a 
                 no reinforcement 
                 adhesive layer 66 
               
               
                   
                   
                   
                 of height H 1   
               
               
                   
                 FIG. 15b 
                 no reinforcement 
                 bonded 
               
               
                   
                   
                   
                 reinforcement 67 
               
               
                   
                   
                   
                 of height H 3  = H″ 
               
               
                   
                   
               
            
           
         
       
     
     In  FIGS. 15   a  and  15   b  upper line of weakness  430  is partial such that head  5  is fastened to opening strip  45  as illustrated in  FIG. 9 . 
       FIG. 16  is a top view of the inner surface of an arc  6  of conical skirt  4  of the cover consisting of a film or sheet material the outer surface of which is generally printed or decorated, used to produce said cover and including:
         two upper 430 and lower 44 lines of weakness ending in notches  460 ,  461  along the axial edge  60  that constitutes the upper edge after said arc has been rolled, and a checkered tab  46 , lower line of weakness  44  defining an upper part  69  and a lower part  65  of height H″, upper line of weakness  430  being a partial line that does not describe a full circle such that head  5  remains fastened to opening strip  45 ,   an upper reinforcement  47  of width L positioned between the two line of weakness  43  and  44 , one end of which  472  constitutes a reinforcement of tab  46 .       
     Arc  6  of height H′ has an upper rim  64  to which the head of the cap and a lower part  65  of height H″ are fastened. 
       FIGS. 17   a  to  21   b  are similar to  FIG. 16  and show other embodiments of the invention. 
     In  FIG. 17   a  upper reinforcement  47  consists of two strips, each one being near a line of weakness  43 ,  44 . 
     In  FIG. 17   b  upper reinforcement  47  comprises a thin strip or line of plastic material positioned along lines of weakness  43 ,  44  and along tab  46 . 
     In  FIG. 18   a , only line of weakness  44  is present. An end  472  of upper reinforcement  47  extends beyond said gripping tab, said end acting as a gripping tab, upper reinforcement  47  extending along lower line of weakness  44 . Upper notch  460  is used to start the tearing of the upper part and to direct said tearing such that it is stopped by the other end of the upper reinforcement to enable head  5  of the cover to remain fastened to opening strip  45 . 
     In this figure lower part  65  of arc  6  comprises a reinforcement strip coated with an adhesive reinforcement  68  that can be activated. 
     In  FIG. 18   b  upper reinforcement  47  has a variable width that first of all increases, if tab  46  is taken as the origin, and then reduces. Lower edge  471  of said upper reinforcement is adjacent to lower line of weakness  44  while upper edge  470  is adjacent to upper line of weakness  43 . 
     In  FIG. 19   a  upper reinforcement  47  consists of a row of strips or lines  48  of plastic material or varnish that extend from one line of weakness  43  to the other  44 . Arc  6  has a lower reinforcement  67  that also consists of a strip or line. 
     In  FIG. 19   b , which is similar to  FIG. 19   a , upper reinforcement  47  is a track that constitutes a conducting mouth that can be used for detection purposes. 
     In  FIG. 20   a , part of which is similar to  FIG. 17   a , the upper reinforcement has an end  472  that extends beyond said tab  46  as in  FIG. 18   a , lower part  65  having a part  66  coated with a layer of adhesive that can be activated. 
     In  FIG. 20   b , which is similar to  FIG. 16 , lower part  65  is covered with a lower reinforcement  67 . 
       FIGS. 21   a  to  21   d  are of various types of tabs  46  of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   According to a first embodiment of the invention the cover may comprise, as an additional means, a so-called second line of weakness  43  all or part of which is separated towards the top of the so-called lower line by a distance L at least equal to 0.5 H, H being the height between the so-called lower line and the upper or top end of said cover  1 , lines of weakness  43 ,  44  that define an opening strip  45  of width L. 
   Advantageously, said line of weakness may not extend around the entire periphery of the cover and constitutes a partial line of weakness  430  such that head  5  of the cover remains fastened to opening strip  45 . Partial line of weakness  430  extends at an angle α that ranges typically between 240 and 320°. 
   Gripping tab  46  is typically positioned along a generating line of said cone and is located between two lines of weakness  43 ,  44  and fastened to said opening strip  45 , said tab  46  using said notches  460 ,  461  to automatically direct the tearing strain when said cover is opened towards said two lines of weakness such that said cover is opened easily, ensuring the remaining lower part  11  of the cover located beneath said lower line  44  stays intact and said cork wire  3 , if fitted, is freed.  FIGS. 21   a  to  21   d  are of various types of tabs  46  of the invention. 
   Said tab  46  may comprise notches or recesses  460 ,  461  made in said film or sheet material constituting said cover, said notches constituting the means to direct the tearing strain of said strip  45 . 
   Typically width L 1  of said tab  46  ranges from 0.5 L to L with L ranging between 1.5 and 4 cm. 
   All the figures of covers of the invention ( FIGS. 6 to 20 ) include a tab  46  that has an upper notch  460  and a lower notch  461  running along its edges in the axial direction. 
   In most of these figures the covers or arcs of the covers comprise a so-called second upper line of weakness  43  all or part of which is separated from the top of the so-called lower line by a distance L at least equal to 0.5 H. 
     FIG. 18   a , however, shows a cover comprising a single line of weakness  44  whereas  FIG. 11   b  shows a cover comprising only two lines of weakness without any additional means. 
     FIG. 18   b  shows a cover comprising a tab of increasing width. 
   In a second embodiment of the invention the cover may comprise, as an additional means, means for reinforcing lower part  11 ,  65 . Said means may consist of a lower reinforcement  67  that increases the mechanical properties of all or part of said lower part  11  and adheres to all or part of the inner surface of said lower part  11 ,  65  at least along said lower line of weakness  44  and parallel to said lower line of weakness, said lower reinforcement  67  may also comprise an adhesive layer that can be activated over all or part of the surface that is intended to adhere to said neck. 
   This embodiment is shown in  FIGS. 12   b ,  14   a ,  14   b ,  15   b ,  17   b ,  18   a ,  19   a ,  19   b ,  20   a  and  20   b.    
   The entire lower reinforcement  67  may comprise a layer that can be activated and constitutes a circular strip  68  the width of which is at least equal to 5 mm and that can extend over all or part of the height of said lower part  11  and that is adjacent to at least the upper edge of said lower part  11  along and parallel to said lower line of weakness  44 . 
   This embodiment is shown in  FIG. 14   a.    
   In a third embodiment of the invention the cover may comprise means for fastening all or part of said lower part  11 ,  65  as additional means. Therefore, said lower part  11  may comprise a layer of glue or adhesive on all or part of the inner surface as fastening means that can be activated and that constitutes a part  66  adhered to said neck, typically after the adhesive has been activated. 
   Said glue or adhesive may comprise a complex layer consisting of a layer that adheres to the glass and a layer that adheres to the material comprising the inner surface of said cover, typically aluminum, paper or a layer of plastic material or varnish. 
   This embodiment is shown in  FIGS. 11   a ,  12   a ,  12   b ,  13   a ,  13   b ,  14   a ,  15   a ,  18   a  and  20   a.    
   In  FIGS. 11   a ,  12   a ,  13   a ,  13   b ,  15   a  and  20   a  the material constituting lower part  11  of the cover is bonded directly to the neck (reference  66  in this configuration) whereas in  FIGS. 12   b ,  14   a  and  18   a  the lower reinforcement is bonded to the neck and in  FIGS. 14   a  and  18   a  the lower reinforcement is a strip (reference  68 ) adhering to the neck. 
   In a forth embodiment of the invention the cover may comprise a so-called upper reinforcement means as additional means. Reinforcement means  47  of said upper part is selected, particularly in terms of type and position on the inner surface of said upper part, to increase the mechanical properties of all or part of said upper part such that when said recipient or bottle is opened for said first time said opening strip  45 , which is created by pulling on gripping tab  46 , removes the whole of said upper part  10  along with it. 
   Said upper reinforcement means  47  may comprise a lateral end  472  that reinforces all or part of said gripping tab  46 . Said lateral end  472  may extend beyond said gripping tab such that said lateral end  472  assumes the role of said gripping tab when the cover is first opened, as shown in  FIGS. 18   a  and  20   a.    
   Reinforcement means  47  may comprise a reinforcement strip or line that has a lower edge  471  adjacent to at least lower line of weakness  44 . 
     FIGS. 13   a ,  13   b ,  16 ,  18   b ,  20   b  show configurations in which the upper reinforcement is a strip that covers and reinforces the inner surface of opening strip  45 . 
     FIGS. 12   a ,  12   b ,  17   a ,  17   b ,  18   a ,  19   b  and  20   a , on the other hand, show various types of reinforcement strips certain of which are only adjacent to the lower line of weakness ( FIGS. 12   a ,  12   b ,  14   b ) and constitute a very thin line  48 , as shown in  FIGS. 12   b  and  14   b.    
   Said reinforcement means  47  may comprise an upper part or edge  470  that may or may not belong to the same reinforcement strip or line, said upper  470  and lower  471  edges being separated by a width L, that is constant or otherwise depending on angular position α, width L ranging typically between 0.4 and 4 cm, average width L being preferably between 0.3 and 0.7 times H, H being the height between the so-called lower line and the upper end or top of said cover  1 . 
     FIGS. 12   a  to  13   a  and  16  to  20   b  are non-limitative examples of the very wide range of reinforcement means  47  possible according to the invention. 
   As illustrated in  FIGS. 13   b  and  18   b , width L is not necessarily constant and increases, typically regularly, with the angular position α, width L being at its smallest at said tab  46  where angle α is equal to 0, as shown in  FIG. 9 . 
   According to different versions, said upper reinforcement means  47  may cover the entire interior surface (see  FIGS. 13   a ,  13   b ,  16 ,  18   b ,  20   b ) or inner periphery of the free part of said opening strip  45  (see  FIGS. 17   a ,  17   b ,  19   b ,  20   a ). 
     FIGS. 18   a  and  19   a  show particular reinforcements in that there is a single line of weakness  44  in  FIG. 18   a  and that the reinforcement in  FIG. 19   a  consists of a row of lines  48  more or less parallel to each other. 
     FIGS. 11   a  to  20   b  (except  FIG. 11   b ) show various combinations of additional means. 
   At least one of the additional means is required in order to implement the invention but 2, 3 or 4 of these additional means may also be used simultaneously, as shown in  FIG. 12   b , depending on which aspects of the invention are to be set off to advantage. 
   According to the invention said upper  47  or lower  67  reinforcement means may consist either of a thin sheet or reinforcement strip, typically of a plastic material (preferably PET or PP), paper, or a layer, strip or line of plastic, resin, varnish or paint material and generally of any means that provide a localized increase in the mechanical characteristics and enable the objectives of the invention to be realized. 
   According to the invention the material constituting said cover may be selected from sheets or strips of Al or Al alloys, Sn or Sn alloys, shrinkable plastic, Al/PO/Al complex multilayers, Al/PO/paper, PO/Al/PO, charged PO/Al/PO, where Al refers to a layer of aluminum, PO a layer of polyolefin (preferably PE) capable of containing a charge that is typically mineral. 
   The thickness of said material in sheets or strips may range between 25 and 50 μm when the material is aluminum or an alloy, between 110 and 150 μm when the material is tin or an alloy, between 60 and 100 μm when the material is a shrinkable plastic film and between 60 and 110 μm when the material is a complex multilayer material, typically Al/PO/Al. 
   Another aim of the invention consists in a method for producing covers  1  of the invention, a method in which:
         a blank of arc  6  of said skirt is cut out of said film or sheet material of height H′,   said lower line of weakness  44  and said notches  460 ,  461  are provided on an axial edge  60 ,   said additional means are provided, being selected from said upper line of weakness  43 , said upper reinforcement means, said lower reinforcement means,   a radial line of heat- or pressure-activated adhesive  63  is applied, typically on the other axial edge  61  of said arc, except on the part matching or opposite said tab  46 ,   said arc  6  is rolled on a chuck by folding axial edge  60  back onto the other axial edge  61 , a line of adhesive is applied between the two edges, or said pre-applied radial line of adhesive is activated, to shape said skirt  4  by pressing edges  60 ,  61  together and possibly creating said grooves  9 , and a head  5  is assembled or created, possibly by adding a part of the head and fastening it typically by thermobonding to upper rim  64  of said skirt that is possibly shrunk and folded.       

     FIGS. 11 to 20   b  show arcs  6  of the invention before they are rolled. 
   In the method of the invention the upper or lower reinforcement can be deposited either by bonding a strip or part of a strip  47  with the mechanical characteristics required, which are typically resistance to tearing, and of a required shape, which is typically part of an annular sector, or by using a gun to apply a strip or line  48  of melted plastic material that is adherent and that hardens when applied. 
   According to the invention said upper and lower reinforcement means may be a self-adhesive label of suitable shape applied to said arc  6 . 
   The method of the invention can be perfectly integrated into the standard methods used to shape covers by rolling arcs and it therefore constitutes a method that is just as economical and productive as the standard method. 
   A further aim of the invention relates to the use of a cover of the invention as an overcapping cap for still wines. Once the measurements of the covers of the invention have been suitably modified they may be used to overcap bottles of still wines, which are typically sealed with a cork, without or without a head. In this configuration the covers do not generally include grooves  9  and said additional means is preferably a second line of weakness  43 . 
   Lower line of weakness  44  is preferably located on glass ring  20 , which is specific to bottles of still wine. 
   Examples of Embodiments 
   Conical covers  1 , such as that in  FIG. 6 , have been have been produced by rolling arcs as shown in  FIGS. 15   a  (test  1 ) and  15   b  (test  2 ) according to the method described above. 
   The cover in  FIG. 6  comprises a skirt  4  and a head  5  with two lines of weakness: an upper line  43  and a lower line  44  separated from each other by a distance L of 30 mm, lower line  44  defining the upper or separable part  10  of the cover and the lower or fixed part  11  of the cover. The cover is shaped by rolling an arc  6  of a skirt according to  FIG. 11   a  and thermobonding or bonding an axial edge  60  to the other edge  61  (not shown in  FIG. 6 ). A dotted line shows line of adhesive  63  that seals the two edges together. 
   Before the cover is rolled lines of weakness  43 ,  44  and notches  460 ,  461  that define said  46  are created, the bottom of each notch  460 ,  461  being located on the corresponding line of weakness  43 ,  44 . As shown in  FIGS. 6 and 11   a , said tab  46  is checkered, i.e. provided with a lattice-work of small scores obtained by stamping when said arc and notches are cut out, in order to differentiate the tab visually and in terms of its appearance and to reinforce the visual contrast between the tab and the rest of the cap to encourage the consumer to use said tab  46  immediately in order to open the cover. 
   Upper part  10  of the skirt is provided with a row of grooves  9  that have both a visual and a technical function as they can enable line of weakness  44  to be broken cleanly without tearing lower part  11  of the skirt accidentally. 
   The inner surface of lower part  11  of the skirt is coated with an annular layer of adhesive  66  that is activated when the cover is applied to the neck and is shown by a dotted line at height H 1  in  FIG. 6 . 
   The measurements of the produced covers are given in  FIG. 6  with namely:
         L=30 mm,   H=43 mm,       

   The width L 1  of the checkered tab shown in  FIG. 6  is 25 mm. 
   The angle at the bottom of notches  460 ,  461  was selected as 75°. 
   The conicity of cover  1  is 6°, i.e. the angle formed by the oblique surfaces of skirt  4  shown in  FIG. 6 . 
   The measurements of arcs  6  in  FIGS. 11 ,  15   a  and  15   b  are: 
   H′=130 mm 
   H″=80 mm 
   Test  1 : 
   A 40 μm-thick strip of aluminum was used as a material the outside surface of which was decorated with a gold-colored varnish. 
   Cover arcs  6  were shaped according to  FIG. 15   a  by applying a layer of widely available, water-activated adhesive to a height H 1  equal to 5 mm using screen printing techniques. 
   Test  2 : 
   A 68 μm-thick strip of Al/PE/Al complex material was used the outer surface of which was decorated with a gold colored varnish. 
   A reel consisting of a strip support was loaded with self-adhesive paper labels of a suitable shape and height H 3  of 25 mm. The labels were then transferred to the blanks of arcs  6 . 
   Test  3 : 
   This test is similar to test  2 . It differs in that a reel consisting of a strip support was loaded with self-adhesive paper labels coated with a layer of widely available, water-activated adhesive. 
   Other Tests: 
   Covers similar to the above were also produced in 30 μm-thick strips of corrugated aluminum but that also comprised an upper reinforcement  47  for said upper part  10  that was positioned just above so-called line of weakness  44 . 
   In a first embodiment, such as that shown in  FIGS. 12   a ,  17   a ,  18   a  and  20   a , upper reinforcement  47  consists of a PE-based black strip that adheres to the sheet of aluminum and is typically 5 mm wide, said strips running along line(s) of weakness  43 ,  44 . 
   In a second embodiment, such as that shown in  FIGS. 12   b ,  14   b ,  17   b ,  19   a  or  19   b , upper reinforcement  47  is provided by applying a “hot-melt” type of resin line  48  using an application gun containing melted resin that solidifies when it comes into contact with the sheet of aluminum. 
   According to one version of this embodiment a line of resin is applied that is quick drying when exposed to ultraviolet rays. 
   In a third embodiment, such as that shown in  FIGS. 13   a ,  13   b ,  16 ,  18   b ,  20   b , said upper reinforcement  47  is provided by a strip that is typically self-adhesive and that covers the inner surface of opening strip  45  and that is more or less the same width L as said opening strip. 
   In a fourth embodiment, such as that shown in  FIG. 13   b , an upper reinforcement  47  is provided that is similar to that in the third embodiment except that width L of the opening strip and reinforcement is not constant and typically increases from gripping tab  46 . 
   Bottles of champagne fitted with cork wires and covers  1  according to the test of the invention and bottles fitted with covers of the background art (covers with “Tircell” of  FIG. 3 ) were subjected to an opening test performed by a group of people representing the population of consumers. They were instructed to proceed normally and not to be any more careful than they would usually be at a social occasion. 
   The covers of the invention were opened entirely satisfactorily in that: 
   a) the whole of the upper part of cover  10  was removed and the cork wire revealed in a single movement by pulling tab  46  between the thumb and index of one hand while the other held the bottle, 
   b) said lower part  11  was not damaged, the rim of said lower part  11  matching said lower line of weakness  44  and being therefore relatively regular and circular. 
   On the other hand, with covers of the background art the results were very irregular with both opening problems as the “Tircell” did not always fulfill its function correctly and broke a considerable number of times. There were also edging problems as more often than not the lower part of the cover was either torn or came away from the neck. 
   It was also observed that once the bottles had been opened and left in an ice bucket and handled a number of times lower cover part  11  of the bottles of the invention was always intact whereas the same could not always be said of the bottles provided with covers of the background art. 
   ADVANTAGES OF THE INVENTION 
   The invention has the double advantage of, on the one hand, overcoming the drawbacks of easy-to-open covers for sparkling wines by enabling the entire upper part  10  of the cover to be removed in a single movement by one hand while the other holds the bottle, and, on the other, to enable covers to be produced without requiring considerable modifications in the standard production methods. The invention also discloses a great many embodiments that can set off certain aspects of the easy-to-open cover to advantage and therefore provides covers with a technical performance level that meets customers&#39; requirements. 
   
     
       
         
             
           
             
                 
             
             
               LIST OF REFERENCES: 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
          
             
                 
               COVER 
                1 
             
             
                 
               UPPER PART OF COVER 
               10 
             
             
                 
               LOWER PART OF COVER 
               11 
             
             
                 
               BOTTLE 
                2 
             
             
                 
               GLASS RING 
               20 
             
             
                 
               CORK WIRE 
                3 
             
             
                 
               TIGHTENING WIRE 
               30 
             
             
                 
               LOOP 
               31 
             
             
                 
               SKIRT OF COVER 
                4 
             
             
                 
               LINE OF WEAKNESS 
               40 
             
             
                 
               LINES OF WEAKNESS + TIRCELL 
               41 
             
             
                 
               LINES OF WEAKNESS// 
               42 
             
             
                 
               UPPER LINE OF WEAKNESS 
               43 
             
             
                 
               partial UPPER LINE OF WEAKNESS 
               430  
             
             
                 
               LOWER LINE OF WEAKNESS 
               44 
             
             
                 
               OPENING STRIP 
               45 
             
             
                 
               TAB 
               46 
             
             
                 
               UPPER NOTCH 
               460  
             
             
                 
               LOWER NOTCH 
               461  
             
             
                 
               UPPER REINFORCEMENT (STRIP) 
               47 
             
             
                 
               UPPER REINFORCEMENT (LINE) 
               48 
             
             
                 
               HEAD 
                5 
             
             
                 
               ARC OF SKIRT 
                6 
             
             
                 
               AXIAL EDGES 
               60,61 
             
             
                 
               UPPER EDGE 
               62 
             
             
                 
               LINE OF ADHESIVE 
               63 
             
             
                 
               UPPER RIM 
               64 
             
             
                 
               LOWER PART 
               65 
             
             
                 
               BONDED PART 
               66 
             
             
                 
               REINFORCED PART/LOWER REINFORCEMENT 
               67 
             
             
                 
               BONDED REINFORCEMENT (STRIP) 
               68 
             
             
                 
               UPPER PART 
               69 
             
             
                 
               NECK 
                7 
             
             
                 
               CORK 
                8 
             
             
                 
               CORK HEAD 
               80 
             
             
                 
               GROOVES 
                9