Note: Descriptions are shown in the official language in which they were submitted.
WO 98/34850 PCTIUS98/02358
_1_
PANEL INTERLOCKING MEANS FOR CARTONS
This invention relates to panel interlocking means for securing together a
pair
of panels, for example, adjacent overlapping panels of a paperboard carton. In
some
situations, these panels are provided by the opposite ends of a wrapper blank
which
are brought together in overlapping relationship and interlocked.
Locking tabs which are struck from one end of the carton wrapper and which
are arranged to be driven through corresponding apertures defined by retaining
tabs,
struck from an opposite end of a wrapper are well known. However, in the
present
invention, the interlocking of panels is effected by causing a locking tab to
be engaged
through an aperture. In the present invention, locking tabs are directed away
from the
free end of their respective panel, such configurations are known, for
example, US 3
351 263 (Wood). This application shows a locking arrangement in which a first
panel
includes a locking tab which is directed away from free end of the first
panel. A
second panel includes a first aperture through which the tab is passed and
then passed
over a portion of the panel located beyond the aperture and is inserted
through a
second aperture in select combination.
A problem associated with known locking arrangements is that the forming of
such locking arrangements is complicated and requires additional features, for
example, additional retaining means or apertures. The more complicated
arrangements
also require precise registration of the two panels that are to be
interlocked.
The present invention seeks to nutigate the problems outlined above by
providing a simplified but secure locking arrangement.
One aspect of the present invention provides panel interlocking means for
securing together a first and a second panel in overlapping relationship, the
first panel
comprising a locking tab struck from the first panel adjacent a free edge
thereof and
extending away from the free edge of the first panel. The locking tab has a
neck
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portion hinged at a base thereof to the first panel and terminating i.n a
shoulder portion
and wherein the second panel includes an aperture struck from the second panel
adjacent a free edge thereof and wherein the apezture is adapted to receive
the locking
tab such that when the panels are locked together the fxee edge of the second
panel,
outboard of the aperture, is located along the locking tab between the base of
the neck
portion and the shoulder portion.
According to 3n optional feature of this aspect of the invexktion the neck
portion may
include a transverse fold line so that the shoulder portion is hinged relative
to the neck
portion.
According to another optional feature of this aspect of the invention a
locking edge
may be formed between the underside of the shoulder portion and the neck
portion.
Preferably, the locking edge is adapted to interengage with a complementary
edge of
1 S an aperture of the first panel which was created by the formation of the
lockiz~,g tab.
Another aspect of the pxesent invention provides panel interlocking means for
securing
together a First panel and a second panel in overlapping rekatioaship, the Fii
st panel
comprisinb a lockir~ tab struck from the first panel adjacent to the free edge
thereof
2 0 and extending away from the free edge of the first panel, the locking tab
bavitag a neck
portion hinged at a base thereof to the first panel and terminating in a
shoulde: portion,
and whexein the second panel includes an aperture struck from t~~Ze second
panel
adjacexu. the free edge thereof, and wherein the aperture is adapted to
receive the
locking tab such that the locking tab overlaps part of the second panel
betweext the
2 5 aperture and the free edge, and wherein a locking edge of the locking tab
is provided
at each of the opposed side edges of the locking tab at the transition between
the neck
portion and the shoul3er portion to interengage with complementary edges of an
aperture created by fornnation of the kocking tab to maintain the first panel
and the
second panel in a locked overkapped relationship.
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According to an optional feature of this aspect of the invention, the neck
portion may include a transverse fold line so that the shoulder portion is
hinged
relative to the neck portion adjacent the locking edges.
According to another optional feature of this aspect of the invention, the
locking edges of and the complementary edges may be curvilinear.
Another aspect of the invention provides a method of securing together a first
panel and a second panel in overlapping relationship, the first panel
comprising a
locking tab struck from the first panel adjacent a free edge thereof and
extending away
from the free edge of the first panel, the locking tab having a neck portion
hinged at
the base thereof to the first panel adjacent the free edge and terminating in
a shoulder
portion, and wherein the second panel includes an aperture struck from the
second
panel adjacent a free edge thereof, which method comprises the following
steps: (i)
folding the locking tab out of the plane of the first panel and towards the
free edge
thereof; (ii) bringing the first and second panels into overlapping
relationship so that
the aperture and locking tab are brought into registry; (iii) inserting the
locking tab
through the aperture; and (iv) folding the locking tab into overlapping
relationship with
the second panel between the aperture and free edge thereof towards its
original
position and inserting it through the aperture from which the locking tab was
struck
such that the locking tab is interengaged with an edge portion of the tab
aperture such
that the first and second panels are locked together in overlapping
relationship.
Preferably, the free edge of the second panel outboard of the aperture is
located along
the locking tab between the base of the neck portion and the shoulder portion.
Another aspect of the invention provides a carton blank incorporating panel
interlocking means having a first panel and a second panel, the first panel
comprising
a locking tab struck therefrom including a neck portion and a shoulder
portion, the
neck portion being positioned adjacent to the free edge of the first panel and
hinged
to the first panel by a fold line at the base of the neck portion and wherein
opposed
side edges of the locking tab at the transition between the neck portion and
shoulder
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portion are each shaped to define a locking edge extending from the tab to
cooperate
with an adjacent locking edge formed in the fizst panel and wherein a locking
apetrturc
is struck froth the second panel spaced from its free edge to receive the
locking tab.
According tQ an optional feature of this aspect of the invention, said neck
portion may
include a transverse fold line so that said shoulder portion is hinged
relative to the neck
portion.
According to another optional feature of this aspect of the invention, there
may further
comprise a locking edge formed between the underside of said shoulder portion
and
said neck portion, said locking edge being adapted to internegage with a
campletnentary edge ox an aperture of the first panel which was created by the
formation of said lockizzg tab. Preferably, said locking edges and said
complementary
edges are curvilinear.
IS
An embodiment of the invention will now be described, by way of example only,
in
which:
FIGURE 1 shows a pair of panels which are positioned opposite ends of a carton
2 o blank, in close proximity, o~o~e of which inrcludes a locking tab and the
other of which
includes lockitlg apertures; and
I?IGLTRES 2, 3 and 4 are perspective views of part of the panels illustrated
in Figure 1
i showing the various wages of interlocking the two panels.
Re~errixig to the drawings, a pair of panels 10, 12 respectively are adapted
to be
placsd in an overlapping relationship and interlocked and aze formed-from
paperboard
ox similar foldable sheet material. The panels 10, 12 may, for exatnple, be
disposed ac
the opposite eztds of one and the same carton blank which is to be formed into
a carton
3 0 sleeve in which panels 10, 12 then provide bottom panels of the carton.
The carton is
used for packaging a plurality of articles, for example, cans. Tt is envisaged
that the
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panel interlocking means for securing together a first and second panel can be
incorQoraced into a variety of carton types, for exaraxple, wraparound, basket
or fully
enclosed without departing from the scope of invention.
Locking tab 14 is strucfc from panel 10 and is hingeably connected thereto by
fold Iine
16 with the locking tab extending away from the free edge. In this embodiment,
the
fold line 16 is substantially parallel to and spaced from the end edge 18 of
panel 10.
The locking tab 14 cornpri5es a neck portion 2t7 and a "shoulder" or main
portion 22.
T"ne neck portion 20 is hingeably eonnrxted to first panzl 10 aloztg fold line
16. As
shown in Figure 1, a pair of ogpositely dispostd cut lines 24, z6 3efane the
side edges
of the neck portion 20 and the main portion 22 is hi~aeably
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connected to neck portion 20 along a transverse fold line 28 which is
substantially
parallel to fold line 16. Optionally, fold line 28 is separated by a cut line
30 to make
folding the shoulder portion 22 easier.
The shoulder portion 22 is separated from panel 10 by a cut line 32 which in
this embodiment is substantially "D shaped" : the cut line 32 can also define
a pair of
interlocking parts 34, 36 positioned along the opposing side edges of shoulder
portion
22. Preferably, the cut lines 24, 26 are curvilinear to define a pair of
oppositely
disposed an anchor tabs 38, 40 connected to first panel 10 and positioned
adjacent to
side edges of neck portion 20. Thus, at the intersectian of cut lines 24 and 3
2 and cut
lines 26 and 3 ~, a locking edge 42, 44 which in this embodiment is
substantially hook
shaped is formed for interlocking parts 34, 36 respectively.
As shown in Figure 1, an aperture 46 which is preferably elongate in shape,
is struck from panel 12, being substantially parallel to the free edge 48 of
second panel
12 and comprising a front edge SO and a rear edge 52, the front edge SO being
nearer
to the free edge 48 of panel 12. Preferably, the front edge SO of aperture 46
is spaced
from the free edge 48 of panel 12 by a distance d which corresponds
approximately
to the length of neck portion 20 (shown in Figure 3). In this embodiment, the
free
edge 48 is formed with an indentation 49 so that the distance is reduced to
the correct
dimensions outlined above. In this embodiment, there are two further locking
tabs 60
and apertures 62 which are substantially identical to locking tabs 14 and
aperture 46
and are not therefore described in any greater detail.
Turning to the construction of the panel interlocking means, illustrated in
Figures 2 to 4, the blank requires a series of sequential folding operations.
The
folding process is not limited to that described below and can be altered
according to
the particular manufacturing requirements.
One method of locking together panels 10 and 12 is first fold the locking tab
14 about fold line 16 into a substantially face contacting overlapping
relationship with
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a portion of first panel 10. The panels 10 and 12 are brought into an
overlapping
relationship with each other, and locking tab 14 can then be folded out of
alignment
with panel 10 and through aperture 46, as illustxated in Figure 2. It will be
appreciated by those skilled in the art that the locking tab may be an
interference fit
with the locking aperture. One advantage of the present invention is that the
locking
process does not require precise registration of the two panels 10 ami 12,
because
locking tab 14 is self locking in its own aperture.
The natural resilience of the paperboard material then aDows the locking tab
to automatically spring back in the direction F into its original position as
shown in
Figure 3. Optionally, guide means is used if manufacturing requirements or the
carton
design means that the locking tab 14 needs to be guided back to its original
position.
Optionally, the shoulder portion 22 of locking tab 14 is folded out of
alignment with
neck portion 20 along fold line 2 8 . I n this embodiment, locking tab 14 is
pushed in
the direction G through the aperture 54 created by the formation of locking
tab 14
such that the interlocking parts 34, 36 and the anchor tab 38, 40 may
interengage, as
shown in Figure 4.
Tension is applied to the panels in opposition to the locking direction, l. e.
in
a direction tending to move the panels apart. Thus, the butt engagement
between the
interlocking parts 34, 36 and the anchoring tabs 38, 40 maintain the locking
tab 14 in
its locked condition. Panels 10, 12 r~em~ain interlocked because the front
edge of
aperture 46 is located along the locking tab 14 between the base of the neck
portion
and the shoulder portion 22 and, preferably, in butt engagement with fold line
16 of
panel 10.
Thus, the free edge of panel 12, outboard of the aperture 4 6 is located along
the locking tab between the base of the neck portion and the shoulder portion.
Further, or alternatively, the lacking tab overlaps part of the second panel
between
said aperture and said free edge, and wherein a locking edge of the locking
tab is
provided at each of the opposed side edges of the locking tab at the
transition between
WO 98/34850 PCTIUS98I02358
the neck portion and the shoulder portion to interengage with the free edge of
the
' second panel outboard of said aperture located along the locking tab between
the base
of said neck portion and said shoulder portion.
The present invention and its preferred embodiment relates to a means of
locking two adjacent panels in a wraparound carton and is shaped to provide
satisfactory strength to maintain the panels in a locked position but with a
degree of
flexibility so that the load transferred to the panels is absorbed by the
carrier. The
shape of the blank minimises the amount of paperboard required. The carrier
can be
formed by hand or automatic machinery. It is anticipated that the invention
can be
applied to a variety of carriers not limited to those of the wraparound type.
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