Abstract:
A metal or plastic pail lid has a neck construction comprising an opening surrounded by a neck incorporating a locking collar surrounding the neck. A plastic closure assembly has an integrally molded sealing channel having an axially extending inner wall and a peripheral interlocking outer wall. The closure assembly is secured to the neck construction with the spout inner wall guided within the neck opening and the spout outer wall axially forced between the outer surface of the upstanding neck and the inner diameter of the surrounding collar whereupon the sealing channel outer wall is interlockingly squeezed between the neck and the surrounding collar to form a liquid-tight, tamper resistant connection.

Description:
[0001]    This application is a continuation-in-part of U.S. Pat. No. 6,368,405 dated May 14, 2002. 
     
    
     
         [0002]    The present invention is directed to an all-plastic dispensing closure assembly for containers and to a method of application of such a dispensing closure assembly to a container. The containers may be open head pails having a metal or plastics lid or a container having a fixed plastic or metal top.  
           [0003]    In the field of plastic, injection molded open head pails a transition is taking place toward all-plastic closures. This movement is principally to accommodate environmental recycling concerns and, of course, also to effect attainable cost reductions. The market at this stage has determined that an all-plastic dispensing closure can be snapped on to the upstanding opening neck of a pail lid and successfully meet the various performance criteria set by United Nations and United States Department of Transportation. To date, however, those all-plastic dispensing closures successfully commercialized still leave some gaps in the desirability agenda.  
           [0004]    For example, U.S. Pat. No. 5,788,100 dated Aug. 14, 1998 discloses an all-plastic snap-on closure made up of a flexible pouring spout surrounded by an annular sealing channel and fitted with an overlying screw cap. A locking ring is integrally connected about the periphery of the screw cap so as to extend radially outwardly of the spout sealing channel. In application the closure is pressed onto a circumferentially enlarged upstanding opening neck causing the sealing channel to snap there over. During the closure application the locking ring is broken away from the cap periphery and axially pressed around the outer wall of the sealing channel so as to lock the same against the opening neck The result is a very strong closure container wall connection. The downside resides in the fact that the locking ring can be easily pried off without damage, leaving the closure exposed to undetected tampering and pilferage which negatively impacts universal acceptance.  
           [0005]    Other examples are U.S. Pat. No. 5,797,525 dated Aug. 25, 1998 and U.S. Pat. No. 5,641,099 dated Jun. 24, 1997 which also show all-plastic snap-on closures made up of a flexible pouring spout surrounded by an annular sealing channel and fitted with an overlying screw cap. These constructions also embody an outer locking ring integrally connected by frangible webs about the periphery of the screw cap. In application, the closure is pressed onto a circumferentially enlarged upstanding opening neck causing both the sealing channel outer wall and the peripheral locking ring to snap thereover. This arrangement causes both the spout outer sealing channel and the peripheral locking ring to expand over the neck enlargement and then relies solely on the elastic memory of the plastic parts to radially contract below the neck enlargement and hold the parts tightly together. The principal problem with this type of construction is the inability under varied manufacturing conditions to consistently retain a tight seal due to elastic memory alone. In addition undetected tampering can also be readily accomplished by simply prying the fitting off of the opening neck.  
         SUMMARY OF INVENTION  
         [0006]    It is an object of the present invention to provide a container neck construction and method of application of a closure assembly combination to such a container neck construction that overcomes these prior art deficiencies in a very simple and straight forward manner. As explained above, the current prior art practice is to one way or another, during application, surround the fully seated sealing channel outer wall with a locking ring introduced as an integral part of the closure.  
           [0007]    According to the present invention, a container neck construction and closure assembly combination includes an upstanding neck. The closure assembly is all-plastic and has an annular sealing channel to surround and sealingly engage the neck. Locking means surround the sealing channel to lock the sealing channel against the neck. By this means, the locking ring differs from prior art combinations in that, instead of being a separable part of the closure assembly, it is integrally molded or otherwise formed in the neck construction part of the pail lid as a raised annular collar spaced from and surrounding the upstanding opening neck. The outer wall of the spout sealing channel is, during application, then squeezed into the annular gap formed between the neck and the collar creating a very strong, liquid tight engagement between the closure and the pail lid. The advantages of the present invention closure and method are immediately apparent. There is no breaking away of relatively fragile parts which are then stretched around other parts. There is no reliance on elastic memory for holding parts together. Most importantly, the tamper resistance of the invention closure is substantially increased, as there is no readily undetectable way the fitting or any part thereof can be pried off the pail lid. This characteristic in itself clearly distinguishes the present invention over other snap-on all-plastic closures currently in use. Moreover, the ultimate simplicity of application of the closure assembly to the neck construction of the pail lid easily constitutes a further advance in the art.  
           [0008]    The neck construction may be part of a plastics or metal lid for an open head pail. If the pail lid is plastic, the locking means is a locking collar concentrically disposed radially outwardly spaced from the neck. If the pail lid is metal, an open annular groove may be concentrically disposed radially outwardly spaced from the neck, the radially outer groove wall forming the locking collar or the locking collar may be formed by an upstanding fold in the lid and radially outwardly spaced from the neck. 
       
    
    
       [0009]    The above and other features of the present invention, are illustrated, by way of example, in the drawing wherein:  
         [0010]    [0010]FIG. 1 is a vertical sectional view of a closure assembly in accordance with a first embodiment of the present invention, prior to application to a container neck construction;  
         [0011]    [0011]FIG. 2 is a vertical sectional view of a container neck construction in accordance with the first embodiment of the present invention;  
         [0012]    [0012]FIG. 3 is a top plan view of a closure assembly in accordance with the first embodiment of the present invention;  
         [0013]    [0013]FIG. 4 is a partial vertical sectional view showing the closure assembly of FIG. 3 initially positioned on the neck construction of FIG. 2;  
         [0014]    [0014]FIG. 5 is a view similar to FIG. 4 and showing the closure assembly in an intermediate position during application;  
         [0015]    [0015]FIG. 6 is another view similar to FIG. 4 showing the closure assembly in fully seated and interlocked final position;  
         [0016]    [0016]FIG. 7 is a vertical sectional view of a closure assembly in fully seated and interlocked final position with a neck construction in accordance with a second embodiment of the present invention;  
         [0017]    [0017]FIG. 8 is a vertical sectional view of a closure assembly in a partially seated position with a neck construction in accordance with a third embodiment of the present invention; and,  
         [0018]    [0018]FIG. 9 is a view of the closure assembly of FIG. 8 in fully seated and interlocked final position in accordance with the method of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]    As shown by FIGS.  1  to  6 , a first embodiment of an all-plastic container closure assembly, generally indicated at numeral  1  in FIG. 1, is seen to consist of a nestable pouring spout  2  molded of low density polyethylene and an overlying screw cap  3  molded of high density polyethylene or similar plastic. The spout is formed with an axially extending dispensing neck  4  closed off by a tear-out membrane  5  having a ring pull  6 . The upper portion of the neck  4  has an external thread  7  and the lower end of the neck is integrally connected to flexible wall  8  in turn joined at its uppermost end to a circumferential sealing channel  9 . The sealing channel  9 , as clearly seen in FIG. 4, has an axially elongated inner cylindrical wall  10  which extends beyond the vertical midpoint of flexible wall  8  and has a downwardly and inwardly extending conical surface  11  further provided with one or more vertical drainage slots  12 . At the upper end portion of inner channel wall  10  above the juncture of spout flexible wall  8  there is an annular, undercut, retaining groove  13 . The sealing channel  9  is further provided with an outer wall  14  having an exterior upward and radially outwardly facing camming surface  15  at its upper end. Camming surface  15  joins a cylindrical outer surface  16  which terminates in an annular upwardly facing load bearing surface or shelf  17  on circumferential presser foot  18 . The bottom of presser foot  18  has a downwardly and radially outwardly facing camming surface  19 . The inner surface of outer sealing channel wall  14  has an internal bead  20  partially closing off the mouth of the sealing channel and terminating at its lowermost end in radially inwardly and downwardly facing camming surface  21 .  
         [0020]    The screw cap  3  has a disc like top  22  with a central cylindrical sidewall  23  depending therefrom and having an internal thread  24  for engagement with the spout thread  7 . A pair of lifting bails  25  surround the cap top  22  and are connected by a series of frangible webs  26  and diametrically opposed hinge points  27 . The screw cap  3  is further provided with a short skirt  28  depending from the periphery of top  22 . An annular locking rib  29  surrounds the lower skirt portion and engages within the spout groove  13  with the cap in assembled position.  
         [0021]    As seen in FIG. 2, a plastics pail lid has a neck construction  30  comprising an upstanding neck  31  surrounding the standard dispensing opening and terminating in a circumferentially enlarged retaining lip  32  and a locking collar  33  concentrically disposed radially outwardly spaced from neck  31  creates an open annular groove  34 .  
         [0022]    Turning to the insertion process as initially viewed in FIG. 4, the closure  1  is placed on the neck  31  with the inner sealing channel wall  10  entering the lid opening and the conical wall surface  11  acting as a guide. In this position the sealing channel outer wall camming surface  21  rests on the neck lip  32 . An axially driven insertion tool  35  having an outer cylindrical wall  36  is placed over the closure with the camming surface  15  acting as a guide so that the lower end of the wall  36  comes in contact with the presser foot bearing surface  17  as the tool body bears against the top of cap  22 . Continued vertical displacement of the tool  35  against the supported pail lid  30  causes the camming surface  21  on bead  20  to squeeze the neck  31  and inner sealing channel wall  18  radially inwardly a small amount a shown in FIG. 5 and due to the pressure of the insertion tool outer wall  36  against the cylindrical surface  16 . At this point the presser foot camming surface  19  is brought into engagement with the inner top corner of the locking collar  33 . As shown in FIG. 6 the final small amount of vertical displacement bumps the presser foot inside the collar  33  so that the bottom surface of the outer channel wall  14  rests against the bottom of groove  34 . In this position it can be seen that the internal bead  20  has moved past the neck lip  32  and become locked securely there under. The insertion tool  35  is then retracted leaving the closure tightly and permanently applied to the container neck construction.  
         [0023]    A second embodiment of a combined closure assembly and neck construction in accordance with the present invention is shown in FIG. 7, wherein like parts have been given the same reference numerals. The closure assembly  1  is essentially the same as the closure assembly of FIGS.  1  to  6 , absent the locking rib  29 .  
         [0024]    A metal pail lid has a pail lid  40  having an upstanding neck  41  surrounding the standard dispensing opening and terminating in a circumferentially enlarged retaining lip  42 . An open annular groove  43  is concentrically disposed radially outwardly spaced from neck  41 , the radially outer groove wall  44  of the groove forming a locking collar  45 .  
         [0025]    The closure assembly  1  makes a simple snap-fit with the neck construction  41  with the sealing channel outer wall camming surface  21  resting on the neck lip  42 . An axially driven insertion tool (not shown, but similar to insertion tool  35  of FIGS.  4  to  6 ) is placed over the closure assembly with the camming surface  15  acting as a guide so that the lower end of the insertion tool outer wall comes in contact with the presser foot bearing surface  17  as the tool body bears against the cap top  22 . Continued vertical displacement of the tool against the supported pail lid  40  causes the inner camming surface  21  on bead  20  to squeeze the opening neck and inner sealing channel wall radially inwardly a small amount, due to the pressure of the insertion tool outer wall against the sealing channel cylindrical surface  16 . At this point the presser foot camming surface  19  is brought into engagement with the inner top corner of the locking collar  45 . A final small amount of vertical displacement bumps the presser foot inside the collar  45  so that the bottom surface of the outer channel wall  14  rests against the bottom of groove  43 . In this position it can be seen that the internal bead  20  has moved past the neck lip  42  and become locked securely thereunder. The insertion tool is then retracted, leaving the closure tightly and permanently applied to the container opening.  
         [0026]    A third embodiment of a combined closure assembly and neck construction in accordance with the present invention is shown in FIGS. 8 and 9, again like parts have been given the same reference numerals. The closure assembly  1  is essentially the same as the closure assembly of FIGS.  1  to  6 , absent the locking rib  29 .  
         [0027]    A metal pail lid  50  has an upstanding neck  51  surrounding the standard dispensing opening and terminating in a circumferentially enlarged retaining lip  52  and an upstanding fold in the lid forms a locking collar  53  having an upper portion  53 A and a lower portion  53 B. Collar  53  is concentrically disposed radially outwardly spaced from neck  51 , creating an open annular groove  54 . Assembly is the same as described for the second embodiment except that, once the internal bead  20  has moved passed the neck lip  52  and become locked securely there-under, it is further secured by crimping the locking collar upper portion  53 A radially inwardly over the presser foot  17 ; as shown in FIG. 9.  
         [0028]    From the foregoing the numerous advantages of the present invention are readily apparent, first and foremost, the closure is substantially more tamper resistant than other all-plastic closure constructions. Vertical retraction of the presser foot  18  from-the groove  34  is prevented by the interlocking undercuts between the opening neck and the outer channel wall. Prying the presser foot out of the groove  34  is a virtual impossibility without clear indication of tampering. The high radial compression created between the collar  30  and the inner channel wall  10  assures a liquid seal under the most rigorous conditions. In addition the radial contraction of the spout inner wall serves to effectively tighten the engagement with the cap skirt  28  so that inadvertent dislodgment of the locking of the locking rib  29  with the groove  13  becomes unlikely due to unavoidable upward force or pressure on the bottom of the nested spout. A further advantage in the construction according to the present invention is the ability to also apply, if need be, a conventional crimped-on closure to the opening neck configuration. This flexibility has significant commercial ramifications.  
         [0029]    Various other changes in or modifications to the closure assembly and neck construction combination and insertion method of the invention; for example, different types of plastic resin could be employed to mould the various elements; the neck construction could form part of the top of a metal or plastic container, such as an oil can.