Note: Descriptions are shown in the official language in which they were submitted.
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CARTON AND CARTON BLANK
FIELD OF THE INVENTION
This invention relates to a carton blank and a carton.
BACKGROUND
Food must generally be packaged in air tight packaging to avoid infestations.
Traditional
cereal boxes have four flaps: two end flaps which fold in and are overlain by
an interior
major flap and an outer major flap. Such a box leaves pin hole openings to its
interior at its
corners. Thus, to be suitable to contain food, these cereal boxes are provided
with an
interior air tight bag.
A number of carton designs are known which provide an air tight carton
avoiding the need
for an air tight bag. One such carton design is used in many milk cartons and
is described,
in one variation, in US4,211,357 to Lisiecki issued July 8, 1980. The carton
bottom has
two major flaps and two end panels which are ears joined between the two major
flaps. A
heat seal adhesive is applied to the ears and one major flap then the ears are
folded in and
the major flaps folded down while the carton sits on a mandrel. Pressure and
heat is then
applied to seal the bottom. The carton top comprises two ears joined between
two major
panels. The two ears are folded in and a heat seal adhesive applied to the
inside top margin
of one of the major panels. The top margins of the major panels are then
pressed together
while heated to seal same. This results in a gable top.
While a gable top carton allows the carton to be sealed after filling, there
is considerable
empty head space in the carton. The gable top also precludes stacking of the
cartons.
Another carton design, often used for long shelf life storage of juice or
other liquids,
comprises a sleeve with, at its top and bottom, two major panels which each
terminate in an
ear-half at either end. For each pair of major panels, a heat seal surface is
provided on the
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inside face of the margin of the major panels. After applying a heat sealable
material, the
pair of major panels is pressed together with heat to form a fin seal. This
also joins opposed
ear-halves; the ears are then folded down and spot glued to the carton.
The fin sealed carton makes better use of the interior volume of the carton,
however, re-
closing of such a carton after opening presents difficulties. In some such
cartons, it is
contemplated that the carton is opened by cutting through the fin seal: in
such case, re-
closing is not possible. In other such cartons, a re-closeable flap (e.g., a
plastic fitment)
may be added to the top of the carton. However, such a flap provides only a
relatively small
access area to the inside of the carton. Thus, while such a flap may be
adequate for a carton
containing a liquid, in many instances it may not be adequate for a carton
containing dry
goods.
Both gable top and fin seal cartons require application of pressure from
opposite sides to
seal the carton top, as well as the presence of a heat sealable material. This
increases the
difficulty of manufacturing such cartons.
US6,056,680 issued May 2, 2000 to Spronk-Dik describes an airtight carton
which requires
the adhesion of a separate material strip to the carton blank.
Accordingly, a need remains for a carton which provides one or more of the
following
features: an air tight seal prior to initial opening, the ability to be re-
closed, and a relatively
large access area on opening.
SUMMARY OF THE INVENTION
The top of a carton, with opposite main panels and opposite side panels, has
an inner and
outer major flap hinged to opposite main panels. The outer major flap has a
fold line
extending along its length in parallel to a hinge line joining the outer major
flap and a main
panel. At each side panel, an ear has an ear portion hinged to the side panel
and an ear
portion hinged to the outer major flap. With this arrangement, the carton may
be re-closed
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by pressing the ears down against the outer major flap so that the outer major
flap folds
about fold line into a concave V-shape.
Accordingly, in one aspect of the present invention there is provided a carton
comprising: a
first main panel; a second main panel; a pair of opposed side panels hinged
between the
main panels; an inner major flap extending along the first main panel and
hinged thereto; an
outer major flap extending along the second main panel and hinged thereto, the
outer major
flap having a width so as to overlap along its length with the inner major
flap; a fold line
extending the length of the outer major flap and paralleling a hinged line
joining the outer
major flap to the second main panel; a pair of opposed outwardly projecting
ears, each ear
having a side panel portion extending from a top of one of the side panels and
an outer
major flap portion extending from an end of the outer major flap and joined to
the ear side
panel portion; the outer major flap being folded inwardly at the fold line to
form a concave
V-shape, the concave V-shape drawing the ears downwardly.
In another aspect of the present invention there is provided a carton
comprising: a first main
panel; a second main panel; a pair of opposed side panels hinged between the
main panels;
an inner major flap extending along the first main panel and hinged thereto;
an outer major
flap extending along the second main panel and hinged thereto, the outer major
flap having a
width so as to overlap along its length with the inner major flap; proximate
each end of the
outer major flap, an outer major flap weakened line defining a closed shape,
each outer
major flap weakened line extending from an outside face of the outer major
flap to a depth
less than a thickness of the outer major flap; a pair of opposed outwardly
projecting ears,
each ear having a side panel portion extending from a top of one of the side
panels and an
outer major flap portion extending from an end of the outer major flap and
joined to the ear
side panel portion; an adhesive bond between the each ear and the outer major
flap
extending within one the closed shape.
In yet another aspect of the present invention there is provided a carton
comprising: a first
main panel; a second main panel; a pair of opposed side panels hinged between
the main
panels; an inner major flap extending along the first main panel and hinged
thereto; a
weakened line extending along the length of the inner major flap so as to
define an inner
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major flap marginal portion between a free edge of the inner major flap and
the weakened
line; an outer major flap extending along the second main panel and hinged
thereto, the
outer major flap having a width so as to overlap along its length with the
inner major flap; a
fold line extending the length of the outer major flap along the free edge of
the inner major
flap; a pair of opposed outwardly projecting ears, each ear having a side
panel portion
extending from a top of one of the side panels and an outer major flap portion
extending
from an end of the outer major flap and joined to the ear side panel portion.
In another aspect of the present invention there is provided a carton blank,
comprising: a
first main panel; a second main panel; a medial side panel hinged to the first
main panel at a
hinge line and to the second main panel at a hinge line; a first major flap
hinged to the first
main panel at a hinge line; a second major flap hinged to the second main
panel at a hinge
line; proximate each end of the second major flap, a second major flap
weakened line
defining a closed shape, each second major flap weakened line extending from
an outside
face of the second major flap to a depth less than a thickness of the second
major flap; a
medial ear panel hinged to the medial side panel at a hinge line, hinged to
the first major flap
at a hinge line and hinged to the second major flap at a hinge line.
In another aspect of the present invention there is provided a carton blank
comprising: a first
main panel; a second main panel; a medial side panel hinged to the first main
panel at a
hinge line and to the second main panel at a hinge line; a first major flap
hinged to the first
main panel at a hinge line; a weakened line extending along the length of the
first major flap
so as to define an inner major flap marginal portion between a free edge of
the inner major
flap and the weakened line; a second major flap hinged to the second main
panel at a hinge
line; a fold line extending the length of the second major flap aligned with
the free edge of
the inner major flap; a medial ear panel hinged to the medial side panel at a
hinge line,
hinged to the first major flap at a hinge line and hinged to the second major
flap at a hinge
line.
In another aspect of the present invention there is provided a method of re-
closing a carton
of a type having a first main panel; a second main panel; a pair of opposed
side panels
hinged between the main panels; an inner major flap extending along the first
main panel
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and hinged thereto; an outer major flap extending along the second main panel
and hinged
thereto, the outer major flap having a width so as to overlap along its length
with the inner
major flap; a fold line extending the length of the outer major flap and
paralleling a hinge
line joining the outer major flap to the second main panel; a pair of opposed
outwardly
projecting ears, each ear having a side panel portion extending from a top of
one of the side
panels and an outer major flap portion extending from an end of the outer
major flap and
joined to the ear side panel portion, comprising: folding the outer major flap
inwardly at the
fold line to form a concave V-shape, the concave V-shape drawing the ears
downwardly.
Other aspects of the invention will become apparent after a review of the
following
description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the figures which illustrate an embodiment of the invention,
figure 1 is a perspective view of a carton,
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figure 2 is a perspective view of a carton blank from which the carton of
figure 1
may be manufactured,
figures 3 to 10 are perspective views illustrating the manufacture of the
carton from
the blank of figure 2,
figures 11 to 16 are perspective views illustrating opening and re-closing of
the
carton of figure 1, and
figure 17 is a perspective view of a re-closed carton.
DETAILED DESCRIPTION
Turning to figures 1, 7 and 9, a carton 20 has two main panels 22 and 24 with
a pair of side
panels 26 and 28 hinged therebetween. At the top of the carton, an inner major
flap 34 is
hinged to main panel 24 and an outer major flap 32 is hinged to panel 22. An
ear 36, 38
projects outwardly from each end of the major flaps 32, 34 and is glued down
to the outer
major flap 32. Each ear has an ear side panel portion 40 hinged to the top of
a side panel, an
ear outer major flap portion 42 hinged to the outer major flap 32, and an ear
inner major flap
portion 44 hinged to the inner major flap 34.
The outer major flap 32 overlaps the inner major flap 34 and the ear portions
42 extending
from the outer major flap 32 overlap respective ear portions 44 extending from
the inner
major flap 34. There is an adhesive bond along this overlapping portion
between an inside
face of the outer major flap 32 and its ear portions 42 on the one hand and
the outside face
of the inner major flap 34 and its upper ear portions 44 on the other. Each
ear 36, 38 is
bonded to the outer major flap 32.
With reference to figures 6 and 7, it is noted that the bottom of the carton
is similarly
configured with an inner major flap 134 and respective ear portions 144
overlapped by, and
bonded to, an outer major flap 132 and respective ear portions 142.
Additionally, the ears
136, 138 are bonded to the outer major panel 132. Alternatively, ears 136, 138
could also
be bonded to side panels 26, 28.
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Returning to figures 1 and 7, and also referencing figure 2, which shows a
carton blank 50
from which carton 20 is manufactured, a weakened line 54 extends along the
inner major
flap 34 and weakened lines 64a, 64b extend along each of ear portions 44. The
weakened
lines 54, 64a, 64b are aligned so as to form one continuous weakened line in
the completed
carton. These weakened lines may be cut scores, lines of perforation, or the
like. These
weakened lines define a marginal portion 55 along which the aforementioned
adhesive bond
extends.
The outer major panel 32 has weakened lines 56, 58 formed as closed (circular)
shapes 66.
These weakened lines extend from the outside face of the carton 20 to a depth
which is less
than the thickness of the outer major flap. (This depth may be 50% of the
thickness of the
outer major flap.) The adhesive bond between each ear 36, 38 and the outer
major flap 32
extends within one of these closed shapes 66.
The outer major flap 32 has a medial fold line 62 which may overlie the free
edge 57 of the
inner major flap 34. The medial fold line 62 defines a base 65 and flap end
portion 63 of
outer major flap 34.
With particular reference to figure 2, in the carton blank 50, each ear 36, 38
has a fi=ee edge
74 with a notch 76; this notch facilitates overlapping of the ear portions 42,
44. A fold line
78a extends in ear 38 from a top corner of main panel 24 to notch 76. A second
fold line
80a extends in ear 38 from a top corner of main panel 22 to the notch 76.
Similar fold lines
78b and 80b extend in ear 36, however, fold line 80b extends from a top corner
of margin
strip 84 defined by hinge line 86. It will also be noted that ears 136 and 138
at the bottom
of the carton blank have similar notches 176 and fold lines 178a, 178b, 180a,
180b.
Carton blank 50 also shows hinge line 88 between main panel 24 and side panel
28; hinge
line 90 between main panel 22 and side panel 28; and hinge line 92 between
main panel 22
and side panel 26. Additionally is shown: a hinge line 94 between main panel
24 and inner
major flap 34; hinge line 96 between side panel 28 and ear 38; hinge line 98
between main
panel 22 and outer major flap 32; hinge line 99 between side panel 26 and ear
36; and
similar hinge lines 194, 196, 198, and 199 at the bottom of the blank.
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Note that a fold line may be structurally indistinguishable from a hinge line;
the two terms
were herein merely to indicate a different function.
To adapt the carton blank 50 for use with foods, an air impermeable coating 51
should be
applied to the interior face of the blank.
To manufacture a carton 20 of figure 1 from a carton blank 50 of figure 2,
adhesive is to
applied one or both of the outside face of margin strip 84 and the inside face
of a margin of
main panel 24 and inner major flap 34. The carton is formed into a sleeve as
illustrated in
the sequence of figures 3 to 5 with the margin strip 84 bonded to the margin
of main panel
24 and inner major flap 34 by the applied adhesive. Next, the bottom inner
major flap 134
is folded down and its attached ear portions 144 are folded down and out.
Adhesive is
applied to either or both of the margin of the outside face of the inner major
flap 134 and its
ear portions 144 or to the inside face of the outer major flap 132 and its ear
portions 142.
The outer major flap and its ear portions 142 are then folded over, and bonded
to, the inner
major flap 134 with its ear portions 144, as seen in figure 6. The notches in
the ear-halves
permit ear portion 142 to be folded over ear portion 144 without interference.
With the ear portions 144 folded down and out, inner major flap 134 is
supported at either
of its ends by the bottom edge of side panels 26, 28. This sufficiently
supports the inner
major flap so that the outer major flap may be pressed thereagainst to bond
the two in the
absence of a mandrel behind the inner major flap. Thus, a mandrel is optional.
Also, in
consequence of the self-supporting inner flap, a hot melt adhesive may be
employed as the
applied adhesive.
Next adhesive is applied to the outside face of outer major flap 132 and the
ears 136, 138
are folded around and bonded to the outer major flap 132, as seen in figure 6.
This
completes the bottom of the carton.
The carton with its completed bottom may then be filled. After filling, the
top inner major
flap 34 is folded down and its attached ear portions 44 are folded down and
out. This is
shown, progressively, in figures 7 and 8. As seen in figure 8, this results in
the top edge of
side panels 26, 28 supporting the ends of the inner major flap 34. Adhesive
(which may be
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hot melt) is applied to either or both of the margin 55 of the outside face of
the inner major
flap 34 and the margin of its ear portions 44 or to the inside face of the
outer major flap 32
inwardly from fold line 62 and to the margins of its ear portions 42. The
outer major flap
and its ear portions 42 are then folded over, and bonded to, the inner major
flap 34 with its
ear portions 44, as seen in figure 9. Lastly, a spot of adhesive may be
applied in each
closed shape 66 of side panels 26, 28 and each (now bonded) ear 36, 38 may be
folded
down and bonded to its respective side panel, as seen in Cgure 10.
It will be apparent that with a line of adhesive forming a bond from ear-to-
ear at both the
top and bottom of the carton 20, there are no pin hole openings to the
interior of the carton.
Thus, at least where the carton has an air impermeable coating, the carton is
air tight.
Consequently, carton 20 may be used as a bagless cereal box.
Optionally, the top of the carton 20 may be closed first, the carton bottom-
filled, and then
the bottom of the carton sealed closed. This has the advantage that it allows
use of a
mandrel when sealing the top of the carton, which assists in ensuring a good
seal at the top
of the carton where adhesive may only bond the marginal portion 55 of inner
major flap 34.
The seal at the bottom is more easily ensured in the absence of a mandrel than
is the seal at
the top because a greater amount of adhesive can be used than can be used at
the top. For
example, a bead may be applied to the outer surface of the inner major flap
134 and a
spaced parallel bead applied to the inner surface of the outer major flap 132.
To open carton 20, ears 36, 38 are grasped and pulled away from outer major
flap 32, as
seen in figure 11. The weakened lines 56, 58 in the outer major flap, which
extend to a
depth which is less than the thickness of the outer major flap, facilitates
this. More
particularly, it is not necessary for the adhesive bond between the ears and
outer major flap
to be broken as carton material within closed shapes 66 simply pulls away with
the ears.
Because the weakened lines 56, 58 do not extend to the depth of the outer
major flap, the
carton remains impermeable to air even after the ears are pulled away.
Next, the flap end portion 63 of the outer major flap 32 may be grasped and
pulled back, as
shown in figure 12. This causes the weakened lines 54, 64a, 64b (figure 2) to
give way
resulting in a tear strip 210 (which previously was the marginal portion 55 of
the inner
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major flap and the marginal portion of its ear portions 44) pulling away with
the outer major
flap 32. Thus, this does not require breaking the adhesive bond between the
outer and inner
major flaps 32 and 34, nor between their respective ear portions 42 and 44.
After the outer
major flap has been pulled back, the interior of the carton may be accessed,
as shown in
figure 13.
To re-close the carton, the ears 36, 38 may be folded outwardly, as seen in
figure 14, this
pulls the inner major flap 34 (now without marginal portion 55) and outer
major flap 32
downwardly as seen in figure 15. The ears 36, 38 are then folded over top of
the outer
major flap 32 and pushed downwardly, as seen in figure 16. This causes the
outer major
flap 34 to bend inwardly at its fold line 62 so as to have a concave V-shaped
profile. Ear
portions 42 are hinged to the base 65 of outer major flap 32. Thus, when the
outer major
flap assumes its concave V-shaped profile, the downwardly directed base 65
draws ear
portions 42 downwardly and away from their ear side panel portions 40.
Additionally, the
outer major flap forces the inner major flap 34 downwardly. This, in turn,
draws ear
portions 44, which are hinged to the inner major flap 34, downwardly and away
from their
ear side panel portions 40. This has the effect of "latching" the ears in
place such that the
carton can only be re-opened by first pulling the ears away from the outer
major panel.
With the carton re-closed, a wide band of base 65 of outer major flap 32 abuts
the inner
major flap 34. This provides a reasonable seal at the top of the carton.
Optionally, the inner and outer major flaps 132, 134 may be embossed so that
the ears 136,
138 are more flush with the bottom of carton 20. Alternatively, the bottom
ears 136, 138
may be folded around and glued to side panels 26, 28, rather than being folded
around and
glued to outer major flap 132.
Other modifications will be apparent to those skilled in the art and,
therefore, the invention
is defined in the claims.
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