Patent Publication Number: US-2013240527-A1

Title: Manually Removable Lid Structure Including Metal Lid and Plastic Ring

Description:
TECHNICAL FIELD 
     This invention relates to an easy open container. In particular, but not exclusively it related to a lid structure for an easy open container for packaging liquids such as paint, or solids such as powders. 
     BACKGROUND ART 
     It is known to provide metal containers for packaging paint in which the container has a body with seamed or integral base, a metal ring which is seamed to the open end of the can body, and a press-on lid which can be opened by inserting a lever into a channel at the edge of the ring. 
     In an alternative design, the press-on lid has a U-shaped channel for inserting the lever, and a flange, which extends radially outwardly from the channel. A plastics ring is clipped over the raw edge of the lid and extends around an outwardly rolled circumferential edge flange of the can body when the lid is pressed down onto the can body. 
     Numerous arrangements of recess have been described but essentially all of these require the insertion of a tool to release an interlock between the lid and container body or ring. These designs rely on the lever opening principle and therefore require some form of tool in order to lever open the container. In some examples, the lever acts against a springy wall of the container, ring or lid so that the container is reclosable and there is minimal distortion of the container on opening. 
     DISCLOSURE OF INVENTION 
     According to the present invention, there is provided a manually removable lid structure comprising: a metal lid, having a centre panel and a outer wall terminating in a generally outwardly extending annulus; and 
     a plastics ring comprising an inwardly extending annular shoulder and a peripheral skirt depending from the shoulder, the skirt having an inwardly extending lug which clips against the edge of the lid with the shoulder extending over the lid annulus, and a lower profile which is complementary to the profile of the upper edge of a container body to which, in use, the lid structure is to be fixed; characterised by line of weakening along which at least part of the lower profile of the ring is manually deformable or tearable for opening the container to which the lid structure is attached. 
     In contrast with lever lids of the prior art, the plastics ring of the lid structure provides openability when the lid structure is fixed to a container, without the need for any tool. After tearing the lower ring profile, the lid structure is removable from the container, such that the container appears to the user to have only two parts. 
     The centre panel of the lid may be joined to the outer wall by a generally U-shaped channel. This prevents excessive intrusion of the lid structure into the headspace of the can body. Typically, sealing compound may be provided around the lid annulus and adjacent the outer wall. 
     The line of weakening is usually tearable and defines a tamper evident strip or band. 
     According to a further aspect of the present invention, there is provided an easy open container comprising: a metal can body having an open top ; the lid structure as described above, with the lower profile of the ring engaging the edge of the can body opening; in which the outer wall of the metal lid is seated within the container body and the outer wall and the container body have complementary outwardly extending beads, and in which, in use, the weakened part of the ring profile is operable manually removing the lid structure from the can body. 
     Typically, the can body has an outward curl at the edge of the opening so that the ring engages this can body curl. According to yet another aspect of the present invention, there is provided a method of sealing an easy open container, the method comprising: 
     placing the lid structure over the open end of a metal container body; applying downward pressure to force the lid and ring combination down onto the container body so that the lower profile of the plastics ring engages the upper edge of the container body and an outer wall of the lid is adjacent part of the container body side wall; and maintaining the downward pressure whilst applying a radially outward expansion force to deform the outer wall of the lid and the adjacent body wall into complementary beads. 
     Generally, the method may be used with a lid structure having a U-shaped channel so that an expandable tool may be inserted into the channel for applying radial force to the channel outer wall to form the beads. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which: 
         FIG. 1  is a perspective view from above of the plastics ring; 
         FIG. 2  is a perspective view from below of the plastics ring; 
         FIG. 3  is a side section of the plastics ring, through the cut in area ‘C’; 
         FIG. 4  is a side section of the plastics ring, through the cut in area ‘D’; 
         FIGS. 5  is a schematic side view showing the plastics ring and metal lid assembly; 
         FIGS. 6 to 9  are schematic side views showing the application of the lid structure onto a can body; and 
         FIG. 10  is a schematic side view of the closed container. 
     
    
    
     MODE FOR THE INVENTION 
     The plastics ring of  FIG. 1  has an annular shoulder  2  and a skirt having an inner wall  3  and an outer wall  4 . A tab feature  5  on the outer wall is provided for gripping by a user when opening a container as is described in more detail below. Lug  6  of the example is a fully circumferential lug for engaging a metal lid to form a lid structure and a lower profile  7  on the inner wall for engaging the container body. 
       FIG. 2  is an underneath isometric view of the ring of  FIG. 1 , showing cut regions ‘A’, ‘C’ and ‘D’. In the side sections of  FIG. 3  and/or  4 , the annular shoulder  2 , lug  6  and tab  5  can be clearly identified. Lower profile  7  includes teeth  8  in uncut regions which assist in gripping the container body. The cut in the ‘C’ area is indicated by reference  9  in  FIG. 3  that of the ‘D’ area by reference  10  which extends from the tab  5  of  FIG. 4 . 
       FIG. 5  shows the lid structure which combines the plastics ring  1  with a metal lid  20 . The lid  20  comprises a centre panel  21 , inner and outer walls defining a channel  22 , the outer wall  23  leading into an outwardly extending annulus  24 , and terminating in a raw edge. As can be seen from the figure, the plastics ring is clipped over the annulus  24  so the shoulder  2  covers annulus  24  and lug  6  covers the edge of the lid at  25 . 
     In  FIG. 6 , downward pressure is applied by tool  40  onto the shoulder  2  to force the lid structure downwardly onto a filled container  30 . As the lower profile  7  contacts can body curl  31 , the ring  1  pivots outwardly and then snaps around the curl into the position of  FIG. 7 . In  FIG. 7 , the lid structure is fixed to the can body  30 , with sealing compound  26  between the annulus  24  of the metal lid and the top of curl  31 . The lower profile  7  of the plastics ring has a shape complementary to that of the curl  31  and provides even contact around the curl. 
     The next stage of applying the lid structure provides further engagement between the outer wall  23  of channel  22 . A downwardly extending portion  41  of the tool  40  has a radially outwardly extending bead  42  which is moved into contact with the outer wall  23  by applying a radial expansion force. Downward pressure is maintained whilst the expansion force is applied to ensure correct positioning of the bead  42  against the outer wall  23 . By maintaining downward pressure during expansion, the compression of the compound is maintained during the expansion. This compression is also maintained after the blocking of the lid in the body and partly by the plastic ring. The combined forces are applied until complementary beads are formed in the lid wall  23  and can body wall  32 , beneath the curl  31 . The tool  40  is then retracted radially, with downward pressure maintained ( FIG. 9 ) and tool  40  removed to leave the finished structure of  FIG. 10 . 
     The invention has been described above by way of example only and changes may be made to the method of forming the lid structure or of applying it to a container body without departing from the scope of the invention as defined by the claims. For example, although the complementary feature  32  has been described as a “bead”, clearly this feature could be series of beads, independent lugs or other complementary feature.