Technical field
[0001] 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
[0002] 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.
[0003] 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.
[0004] 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 the invention
[0005] 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.
[0006] 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.
[0007] 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.
[0008] The line of weakening is usually tearable and defines a tamper evident strip or band.
[0009] 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.
[0010] 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.
[0011] 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
[0012] Preferred embodiments of the invention will now be described, by way of example only,
with reference to the drawings, in which:
[0013] Figure 1 is a perspective view from above of the plastics ring;
[0014] Figure 2 is a perspective view from below of the plastics ring;
[0015] Figure 3 is a side section of the plastics ring, through the cut in area 'C';
[0016] Figure 4 is a side section of the plastics ring, through the cut in area 'D';
[0017] Figures 5 is a schematic side view showing the plastics ring and metal lid assembly;
[0018] Figures 6 to 9 are schematic side views showing the application of the lid structure
onto a can body; and
[0019] Figure 10 is a schematic side view of the closed container.
Mode(s) for carrying out the invention
[0020] The plastics ring of figure 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.
Figure 2 is an underneath isometric view of the ring of figure 1, showing cut regions
'A', 'B', 'C' and 'D'. In the side sections of figure 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 figure 3 that of the 'D' area by reference 10 which
extends from the tab 5 of figure 4.
[0021] Figure 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.
[0022] In figure 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 figure 7. In figure 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.
[0023] 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 (figure 9) and tool 40 removed to leave the finished
structure of figure 10.
[0024] 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.
1. 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.
2. A lid structure according to claim 1, in which the centre panel of the lid is joined
to the outer wall by a generally U-shaped channel.
3. A lid structure according to claim 1 or claim 2, further including sealing compound
around the lid annulus and adjacent the outer wall.
4. A lid structure according to any one of claims 1 to 3, in which the line of weakening
defines a tamper evident strip or band.
5. An easy open container comprising:
a metal can body having an open top with an outward curl at the edge of the opening;
the lid structure of claim 1, with the lower profile of the ring engaging the can
body curl;
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 is operable manually removing the lid structure
from the can body.
6. A method of sealing an easy open container, the method comprising:
placing the lid structure of claim 1 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 a complementary
bead.