Note: Descriptions are shown in the official language in which they were submitted.
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CARTON AND CARTON BLANK
Background of the Invention
The invention relates to a carton or sleeve for accommodating one or more
articles for
example cans, bottles or the like formed from one or more blanks of paperboard
or other
suitable foldable sheet material and more particularly to a carton capable of
being formed into
a sealed compartment including a cover flap with mean for releasably fastening
the cover flap
to the carton.
to
The invention is particularly useful where it is desirable for cartons
containing articles to be
enclosed to protect the or each article.
One example of reclosable sleeves formed from one or more blanks of cardboard
is found in
US3,078,030, which illustrates a carton having integral hinged top that is
reclosable. The top
is provided by a front cover panel and a spacer panel secured to one side of
the front cover
panel to interfit with a mating upper portion of the front panel of a box.
Fastening means is
formed from a detached double layer portion of the front panel. However, the
detached
portion is attached to the inside surface of the cover flap resulting in a
stepped non-flat front
2o surface.
30
A second aspect of the invention is concerned with the provisions of a
frangible connection
for releasably fastening the cover flap. More particularly, a tear strip
arrangement is
disclosed.
There are several known types of tear line in common use, examples of which
are illustrated
in US2,28,552 or US3,355,089. However, one problem associated with known tear
lines or
strips is that the action of tearing is difficult to control. For example, the
grain direction of the
board or direction of tearing force will influence the tear direction.
To try to encourage tearing along a predetermined path tear lines are used.
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A problem with known tear arrangements is that, in certain circumstances the
tear may
deviate from the desired path leading to an irregular tear line path or worse,
deviation from
the tear line completely which may result in destroying the integrity of the
carton.
Summary of the Invention
A first aspect of the invention provides a carton having a tear line
comprising a plurality of
perforations or short slits arranged in at least three rows, wherein the
perforations or slits of
each row is offset the perforations or short slits of the next adjacent row.
Preferably, the perforations in a row are spaced by a distance in the range of
substantiallylmm to 5mm. More preferably, each row is spaced from the next
adjacent row
by a distance of substantially O.Smm to 2.Smm.
A second aspect of the invention provides a carton having a wall provided with
a tear open
feature which comprises a tear initiating means formed in the wall and at
least three tear line's
extending from the tear initiating means toward the perimeter of the wall,
wherein each tear
line comprises a plurality of perforations or short slits arranged in at least
three rows, wherein
2o the perforations or slits of each row is offset the perforations or short
slits of the next adj acent
row
The tear open feature rnay comprise four tear lines extending towards the four
corners of the
wall respectively.
Optionally, the tear initiating means comprises a push tab struck from the
wall.
A third aspect of the invention, in a carton formed from paperboard or other
sheet material of
like function, a tear structure which defines a join between two adjacent
panels, means to
3o grasp a panel to be torn away defined, at least in part, by said tear
structure so that it can be
displaced out of the plane it occupies at rest and fold lines disposed between
said means and
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said tear structure to enhance the amount by which said tear away panel can be
displaced so
that shear forces exerted on the tear structure are sufficient to cause
tearing at the tear
structure whereby the tear away panel can be removed from the carton.
According to an optional feature of the third aspect, the tear away panel
provides access to the
carton contents when removed.
Preferably, the tear away panel is a top panel of the carton and wherein the
tear structure
extends around the periphery of that panel and wherein said means for grasping
the panel is
1o disposed remote from its periphery, said fold lines extending from said
means in a
multiplicity of directions to meet said tear structure at a plurality of
locations.
More preferably, said tear structure comprises at least two adjacent perforate
lines wherein
the perforations in one of said lines are disposed intermediate the
perforations in the next
adjacent line and wherein the spacing between said adjacent lines is no
greater than the
spacing between the perforations of either one of them.
A fourth aspect of the invention provides a blank for forming a carton having
a tear line
comprising a plurality of perforations or short slits arranged in at least
three rows, the
2o perforations or slits of each row is offset the perforations or short slits
of the next adjacent
row. Preferably, the perforations in a row are spaced by a distance in the
range of
substantially lmm to Smrn. More preferably, each row is spaced from the next
adjacent row
by a distance of substantially O.Smm to 2.Smm.
Brief Description of the Drawi~s
Exemplary embodiments of the invention will now be described, by way of
example only,
with reference to the accompanying drawings in which: .
FIGURE 1 is a plan view of a blank for forming a carton incorporating the tear
line
arrangement according to a first embodiment of the invention;
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FIGURE 2 is a perspective view of the carton formed from the blank illustrated
in Figure 1 in
a set-up and loaded condition;
FIGURES 3 and 4 illustrate the carton with the cover flap partially torn open;
FIGURE 4a is an enlarged view of the tear strip feature;
FIGURE 5 illustrates a blank according to a second embodiment of the
invention;
l0
FIGURE 6 illustrates a perspective view of the carton formed from the blank of
Figure 5 in a
set-up and loaded condition; and
FIGURE 7 illustrates the carton of Figure 6 with the cover panel fully torn
open.
Detailed Description of the Preferred Embodiments
Referring first to Figure 1, there is shown a unitary blank 10 for forming a
carton made from
paperboard or similar foldable sheet material. The carton is adapted to hold
one or more
2o articles. In this embodiment the blank 10 comprises a base panel 12, first
side wall panels 14,
top panel 16 and second side wall panel 18 hingedly connected together in
series along fold
lines 20, 22 and 24 respectively.
There may further comprise opposed end wall panels 26, 30 hingedly connected
to the
opposed end edges of base panel 12 along fold lines 28 and 32 respectively. In
this
embodiment, the base panel is substantially square although it is envisaged
that other shapes
of the base panel andlor sleeve can be adopted according to the shape andlor
size of the
articles) to be contained.
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In those embodiments with end wall panels 26 and 28, there further comprises
opposed end
flaps 34 and 38 hingedly connected to opposed edges of top panel 16 along fold
lines 36 and
40.
In this embodiment, the support flaps are provided along the longitudinal
edges of the side
wall panel 14 and 18 respectively. As shown in Figure 1, there comprises side
flaps 42a and
42b hingedly connected to the opposed edges of side panel 14 along fold lines
44a and 44b.
Similarly, end flaps 42c and 42d are hingedly connected to the opposed edges
of second side
wall panel 18 along fold lines 44c and 44d.
to
There further comprises a securing flap 46 hingedly connected to base panel
along fold line
48, to secure the opposite ends of the blank together. The securing flap 46
may be provided
with fold lines 50 and 52.
i5 One aspect of the invention provides a one or more detachable cover flaps
formed in the top
wall panel 16. In this embodiment there comprises four cover flaps 54, 56, 58
and 60
provided to cover the top surface of the carton. The cover flaps are hingedly
connected to the
carton both along fold lines 22, 40, 24 and 36 respectively.
20 The cover flaps are frangibly interconnected together by frangible lines:
so in this
embodiment, cover panel 54 is frangibly connected to cover panels 56 and 60
along frangible
lines 66 and 68. Likewise, cover panel 58 is frangibly connected to cover
panels 60 and 56
along frangible lines 62 and 64.
25 The cover flaps are, in this embodiment, triangular in shape although other
polygonal shaped
are envisaged without departing from the scope of invention. In order to
assist in separating
adjacent cover flaps, there further comprises a push tab 70, which is
detachably connected to
the top panel. In Figure 1 the tab 70 is centrally positioned at the point the
frangible lines 62,
64, 66, 68 interconnect.
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At each of the opposing ends of frangible lines 62, 64, 66 and 68, there is
provided a fold line
62a, 62b; 64a, 64b; 66a, 66b; 68a, 68b bisecting the frangible lines shown in
Figure 4. The
fold lines prevent the tearing from going beyond the ends of the frangible
lines, by dissipating
the tearing forces.
Another aspect of the invention relates to the structure of the frangible
lines 62, 64, 66 and
68. Figure 4 and 4A illustrate the preferred embodiment of tear line 68 which
are formed
from three or more individual rows 72, 74 76 comprising a plurality of
perforations or short
slits. In each row, a perforation is spaced from the next adjacent perforation
by a distance L.
to The distance L will vary according to particular tear characteristics,
although it has been
found that a usable range of distance L is between approximately 1 and 5 mm.
Each row 72,
74, 76 is also spaced from the next adjacent row by a distance C. The distance
C will vary
according to particular tear characteristics required, although it has been
found that a usable
range of distance C is between approximately 0.5 and 2.5 mm.
Each row of perforations is offset the next row so that the perforations
appear to have a
"stair" shape as shown in Figure 4A.
In use, the tear line 68 has been found to be more effective than a tear strip
with one or two
2o rows of slits because the central row of perforations 74 transmits the tear
along its length -
the force of the tear passes through this central line. The shearing forces
are then applied
across one side or the other side of the central row 74 to tear the space C
between the central
row 74 and the outer rows 72 and 76, as the tear moves along the tear line.
Thus, it far easier to control the direction of tearing by allowing a degree
of flexibility as to
where tear takes place within the outer rows.
One advantage of this type of tear line is that it is possible to produce a
rounded tear strip, for
example to follow the shape of the logo on the advertising indicia printed
onto the board.
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It is envisaged that any of the embodiments of the carton of the present
invention can be
formed by a series of sequential folding and gluing operations, which can be
formed in a
straight-line machine so that the carton is not required to be rotated or
inverted to complete its
construction. The folding process is not limited to that described below and
can be altered
according to particular manufacturing or user requirements. For example, the
carton could be
part constructed whereby side panel 18 and securing flap 50 are secured
together to form a
tubular structure before loading it with articles.
The base wall panel 12, opposed side wall panels 14, 18 and top panels 16 are
folded out of
to alignment along fold lines 20, 22 and 24 and are folded into a tubular
structure and securing
flap 46 is secured to side panels 18 by glue or other means known in the art.
The articles) is loaded into the carton by known packaging means.
The support flaps 42 are folded inwardly along fold lines 44 and the opposing
ends are
constructed by folding end wall panels 26 and 30 upwardly along fold lines 28
and 32
respectively. Likewise the end flaps 34 and 38 are folded downwardly along
fold lines 36 and
40 and the outer face of the end flaps 34 and 38 are secured to the inner face
of end wall
panels 26 and 30 by glue or other means know in the art. Thus the carton is in
a set up and
loaded condition as shown in Figure 2.
In order to gain access to the interior of the carton the push tab 70 is
depressed inwardly by
the user to reveal an edge 71 which is gripped by the user to tear one of the
cover flaps 56 in
an upward and outward direction as shown in Figure 3. As the cover flap 56
continues to be
pulled outwardly the tear lines 64 and 66 tear to reveal an access aperture A.
The tearing
process corresponds to that described above and illustrated in Figures 4 and
4A.
A second embodiment is illustrated in Figures 5, 6 and 7, which embodiment
shares many
identical panels and fold lines so like parts have been designated by the same
reference
3o numerals with the prefix '1'. Therefore, only the differences will be
described in any greater
detail.
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The carton blank 110 is provided with a unitary cover panel 116 hingedly
interconnecting
side wall panels 114 and 118. The unitary cover panel 116 is substantially
square in shape
being defined along its edges by tear lines 162, 164, 166 and 168. In some
embodiments,
there further comprises one or more fold lines 167, 169, 171, 173 to direct
the lifting forces,
described in more detail below. A push tab 170 is provided in the central
region of the cover
panel 116, although in other embodiments it could be positioned close to one
corner of the
cover panel to help with starting the tearing off from that corner.
to The construction of the second embodiment is identical to the first
embodiment as shown in
Figure 6, so shall not be described in any greater detail.
In order to remove the cover panel, the push tab 170 is depressed to reveal an
aperture.
Thereafter the user inserts a finger into the aperture and pulls the cover
flap 116 which is then
detached from the remaining panels of the carton by tearing along tear lines
162, 164, 166 and
168, as shown in Figure 7. One advantage of this arrangement is that the cover
flap is
removed from the carton with a single pulling action.
Beneficially the embodiments of the invention hereinbefore described provided
a structure
that is sufficiently strong to retain articles and to provide an integral
sleeve or enclosed
carton. The use of paperboard material provides an environmentally alternative
to cartons
made from plastic material and the sleeves made from paperboard can include
printed matter
for marketing purposes.
It will be recognized that as used herein, the terms "top", "bottom", "side",
"end", "upper"
and "lower" with respect to the panels of the carton (or carton blank) are
relative terms, and
that the carton (formed from the blank) may be re-oriented as necessary or as
desired. It will
be further recognized that rather than the bottom wall being formed from the
interlocked
panels, the carton blank may be rearranged whereby some other wall such as a
top wall or a
3o side wall is formed from the interlocked panels.
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Any reference to hinged connection should not be construed as necessarily
referring to a single
fold line only: indeed it is envisaged that hinged connection can be formed
from one or more of
one of the following, a score line, a frangible line or a fold line, without
departing from the
scope of invention.
The invention and its preferred embodiment relate to a carton or a sleeve
which is shaped to
provide satisfactory rigidity to hold items such as information discs for
example floppy or zip
discs or foodstuff with a degree of flexibility. The shape of the blank
minimizes the amount
of paperboard required for the carton. The carton can be constructed from a
flat collapsed
to condition to position of use and/or loaded by hand or automatic machinery.
It is anticipated
the invention can be modified without departing from the scope of the
invention: for example,
side and end panels can be increased in height or width to provide a carton to
receive one or
more articles of different shapes and/or sizes. Additionally, the tear lines
shown in the
various embodiments can be applied to other known carton types, for example a
fully
enclosed carton or wraparound cartons for beverage containers or for
foodstuffs, without
departing from the scope of invention.
