Variable volume beverage container

Abstract

A variable volume container for beverages charged with gas in which a concave cylindrical upper part is screwed into a convex cylindrical base and leaves a very small gas volume above the beverage to thereby prevent loss of gas from the beverage and loss of quality.

1 . A variable volume beverage container comprising: 
 a vertically elongated upwardly open base having a cylindrical wall formed at least along an inner surface with formations distributed over at least a major part of a height of the wall;    a downwardly open upper part having a wall formed at least externally with formations mating with the formations of said base and enabling variable height insertion of said upper part in said base for varying an internal volume of said container as defined by said base and said upper part, said upper part forming a seal with said base preventing escape of gas from said container;    a mouth on said upper part affording access to an interior of said container; and    a removable cap on said mouth.    
   
   
       2 . The variable volume beverage container defined in  claim 1  wherein said base and said upper part are molded from synthetic resin and said formations are mating screw threads.  
   
   
       3 . The variable volume beverage container defined in  claim 2  wherein said base and upper part are each molded from a synthetic resin selected from the group which consists of polyvinyl chloride, polypropylene, polyethylene, nylon and polyethyleneterephthalate.  
   
   
       4 . The variable volume beverage container defined in  claim 3  wherein said cap is a screw cap threaded onto a neck of the container surrounding said mouth.  
   
   
       5 . The variable volume beverage container defined in  claim 4  wherein said wall of said base is formed on an upper end thereof with a reinforcing ring.  
   
   
       6 . The variable volume beverage container defined in  claim 5 , further comprising a sealing ring between an upper end of said wall of said base and said wall of said upper part and sealing between them.  
   
   
       7 . The variable volume beverage container defined in  claim 6 , further comprising a bead formed on said upper part and bearing against said upper end of said wall of said base upon full insertion of said upper part into said base.  
   
   
       8 . The variable volume beverage container defined in  claim 7  wherein said walls are generally cylindrical.  
   
   
       9 . The variable volume beverage container defined in  claim 8  wherein said neck, said mouth and said cap are positioned along a common axis of said walls.  
   
   
       10 . The variable volume beverage container defined in  claim 8  wherein said neck, said mouth and said cap are laterally offset from a common axis of said walls.  
   
   
       11 . The variable volume beverage container defined in  claim 2  wherein said threads have rounded cross sections.  
   
   
       12 . The variable volume beverage container defined in  claim 2  wherein said upper part has diametrically opposite webs adjacent said mouth and facilitating screwing of said upper part into and out of said base.  
   
   
       13 . The variable volume beverage container defined in  claim 2  wherein said wall of said base is formed on an upper end thereof with a reinforcing ring.  
   
   
       14 . The variable volume beverage container defined in  claim 2 , further comprising a sealing ring between an upper end of said wall of said base and said wall of said upper part and sealing between them.  
   
   
       15 . The variable volume beverage container defined in  claim 2 , further comprising a bead formed on said upper part and bearing against said upper end of said wall of said base upon full insertion of said upper part into said base.  
   
   
       16 . The variable volume beverage container defined in  claim 2  wherein said walls are generally cylindrical.  
   
   
       17 . The variable volume beverage container defined in  claim 4  wherein said neck, said mouth and said cap are positioned along a common axis of said walls.  
   
   
       18 . The variable volume beverage container defined in  claim 4  wherein said neck, said mouth and said cap are laterally offset from a common axis of said walls.