Note: Descriptions are shown in the official language in which they were submitted.
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FOLDABLE COMPOSITE PANEL WITH COMPRESSION RELIEF HINGE
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No.
60/754,929, filed December 29, 2005, the entirety of which is incorporated
herein
by reference.
TECHNICAL FIELD
This invention relates generally to packaging, and in particular, to cartons
that include multi-layer panels that are folded to form a corner of a carton.
BACKGROUND OF THE INVENTION
Stronger carton walls are desirable for securely packaging items and for
transporting heavy items. One method of strengthening selected walls or
portions of a carton is to thicken them. For example, a reinforcing layer can
be
attached to a primary layer to form a composite panel that defines one or more
composite walls or portions of the carton. However, the increased thickness of
such a composite panel creates increased folding resistance when folding the
composite panel, for example, to form a corner of the carton.
The increased folding resistance is due to portions of the reinforcing layer
being in compression and to portions of the primary layer being in tension.
The
folding resistance caused by the tension and compression causes multiple
problems including cracking or other damage to the primary and/or reinforcing
layer, an irregular or otherwise aesthetically unappealing corner of the
carton,
and interference with the ability of a machine to fold the composite panel
during
the packaging process. What is needed is a foldable multi-layer panel that can
be easily folded to provide a corner of a carton.
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SUMMARY OF THE INVENTION
The various embodiments of the present invention overcome the
shortcomings of the prior art by providing a muiti-layer or composite panel
with an
arrangement of-overlying aligned hinges, including a compression relief hinge
and a primary hinge, that facilitate folding the composite panel. The
compression
relief hinge is formed in one of the layers of the composite panel and, as the
composite- panel is folded along the primary hinge, the compression relief
hinge
bulges away from the primary hinge to reduce congestion in the folding area.
Thereby, the thickness of the material in the area where the composite panel
is
folded is essentially reduced and the composite panel can be easily folded
along
the primary hinge.
According to an exemplary embodiment, a composite panel includes a
primary layer that includes a primary hinge. The primary hinge is defined by
at
least one fold line. The composite panel further includes a reinforcing layer
that
includes a compression relief hinge. The compression relief hinge is defined
by a
pair of distal fold lines and a medial fold line that is disposed between and
spaced
apart from the distal fold lines.
At least a portion of the reinforcing layer is secured to the primary layer,
such that the primary hinge and the compression relief hinge are aligned. In
certain embodiments, the primary layer and the reinforcing layer are secured
to
one another on opposite sides of the compression relief hinge. The compression
relief hinge portion of the reinforcing layer is not secured to the primary
layer so
that the compression relief hinge can move with respect to the primary hinge.
The primary layer and the reinforcing layer are aligned such that a fold line
that
defines the primary hinge is disposed between the distal fold lines that
define the
compression relief hinge. In certain embodiments, a fold line that defines the
primary hinge is aligned with a medial fold line that defines the compression
relief
hinge. In sum, the primary hinge overlies the compression relief hinge so that
when the composite panel is folded about the primary hinge and the compression
relief hinge, the distal fold lines and the medial fold line cooperate to form
a
furrow that buckles away from the primary hinge.
The spaced apart medial and distal fold lines define bulge panels. In
certain embodiments, the distances between the fold lines that define the
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compression relief hinge, or otherwise the widths of the bulge panels, are
functions of the thickness of the layers of the composite panel.
Further, in certain embodiments, the dimensions of the fold lines that
define the compression relief hinge are functions of the thicknesses of the
layers
of the composite panel. The medial and distal fold lines can have widths and
depths such that the bulge panels or otherwise the material of the compression
relief hinge can collapse the cavities defined by the medial and distal fold
lines as
the compression relief hinge is folded along the fold lines. The collapsing of
the
cavities facilitates folding the bulge panels or otherwise the furrowing of
the
compression relief hinge. In such embodiments, the cavity of each of the
distal
fold lines can be formed in a first surface or side of the reinforcing layer
and the
cavity of the medial fold line can be formed in a second surface or side of
the
reinforcing layer.
In certain embodiments, the width of the medial fold line is greater than the
width of the distal fold lines. A wider fold line is typically easier to
buckle,
collapse, or initiate a fold along. To form a wider medial fold line, in
certain
embodiments, the medial fold line is formed from a group of three or more
substantially parallel weakened lines that are substantially adjacent to one
another or otherwise directly abutting one another. The group of weakened
lines
cooperates such that the medial fold line collapses when the composite panel
is
folded. To that end, at least one in the group of weakened lines is
comparatively
weaker than the other score lines in the group. In other words, the
comparatively
weaker weakened line can be folded more easily than the others, and thus,
defines the preferred location of the inward collapse of the medial fold line.
The
comparatively weaker weakened line is made more easily foldable by means of
any composition, arrangement, combination, or series of at least one slit,
cut, half
cut, deep score, crimp, or perforation.
Briefly, the present invention is described in the context of a carton having
first and second at least partiatly composite walls that are hingedly
connected to
one another. The first wall is a reinforced top wall and the second wall is an
end
wall that is at least partially reinforced to provide a stronger handle
opening.
Specifically, the reinforced end wall includes a reinforced end flap that is
hingedly
connected to the reinforced top wall. The reinforced top wall includes a
primary
layer and a reinforcing layer, wherein at least a portion of the reinforcing
layer is
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secured to the primary layer in a face-contacting arrangement. The reinforced
end wall includes a primary layer that is hingedly connected to the primary
layer
of the top wall along a primary hinge, and a reinforcing layer that is
hingedly
connected to the reinforcing layer of the top wall along a compression relief
hinge. The reinforcing layer of the end wall is secured to the primary layer
of the
end wall in a face-contacting arrangement.
The foregoing has broadly outlined some of the aspects and features of
the present invention, which should be construed to be merely illustrative of
various potential applications of the invention. Other beneficial results can
be
obtained by applying the disclosed information in a different manner or by
combining various aspects of the disclosed embodiments. Accordingly, other
aspects and a more comprehensive understanding of the invention may be
obtained by referring to the detailed description of the exemplary embodiments
taken in conjunction with the accompanying drawings, in addition to the scope
of
the invention defined by the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. I is a plan view of an exemplary blank for forming a carton.
FIG. 2 is a detail view of a compression relief hinge formed in the blank of
FIG. 1.
FIGs. 3 and -4 perspective views illustrating steps for forming a carton, -the
carton being formed from the blank of FIG. 1.
FIGs. 5 and 6 are sectional perspective views of a portion of the carton of
FIGs. 3 and 4 illustrating steps for forming the carton.
FIGs. 7 and 8 are sectional side elevation views of the portion of the
carton of FIGs. 5 and 6.
FIG. 9 is an end elevation view of an exemplary arrangement of dies for
forming a compression relief hinge in a layer of material.
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DETAILED DESCRIPTION
As required, detailed embodiments of the present invention are disclosed
herein. It must be understood that the disclosed embodiments are merely
exemplary of the invention that may be embodied in various and alternative
forms, and combinations thereof. As used herein, the word "exemplary" is used
expansively to refer to embodiments that serve as illustrations, specimens,
models, or patterns. The figures are not necessarily to scale and some
features
may be exaggerated or minimized to show details of particular components. In
other instances, well-known components, systems, materials, or methods have
not been described in detail in order to avoid obscuring the present
invention.
Therefore, specific structural and functional details disclosed herein are not
to be
interpreted as limiting, but merely as a basis for the claims and as a
representative basis for teaching one skilled in the art to variously employ
the
present invention.
Referring now to the drawings in which like numerals indicate like
elements throughout the several views, the drawings illustrate certain of the
various aspects of an exemplary embodiment of a carton having walls that are
at
least partially defined by a composite panel that includes multiple layers of
sheet
material. The composite panel includes an arrangement of overlying hinges that
facilitate folding the composite panel to fold the walls. Specifically, at
least one of
the layers of sheet material includes a compression relief hinge that buckles
away from a hinge in another of the layers of sheet material to facilitate
folding
the composite panel to form a corner of the carton.
It should be understood that the arrangement of overlying hinges is
illustrated in the context of an exemplary carton for purposes of teaching and
that
the scope of the invention is not limited to the elements or configuration of
the
exemplary carton. Rather, the compression relief hinge can be, applied to any
container, carrier, carton, insert, package, panel, structure, or the like
that
includes panels or walls formed from multiple layers of sheet material and
that
are folded.
Referring to FIGs. I and 4, an exemplary carton 200 is formed from an
exemplary blank'100, which is preferably a single sheet of suitable substrate.
It
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is to be understood that, as used herein, the term "suitable substrate"
includes all
manner of foldable sheet material such as paperboard, corrugated board,
cardboard, plastic, combinations thereof, and the like. In the illustrated
embodiments, a unitary blank 100 is used to form the carton 200, although it
should be recognized that two or more blanks may be employed to provide the
carton structure.
Referring to FIG. 1, the exemplary carton blank 100 is further described.
For purposes of reference, the side of the carton blank 100 shown in FIG. 1 is
defined as the outside surface, and the opposing side of the carton blank 100
is
defined as the inside surface. The carton blank 100 includes primary panels
102,
104, 106, 108 and a reinforcing panel 110 that are hingedly connected one to
the
next along fold lines 112, 114, 116, 118. It should be understood that, in
alternative embodiments, the reinforcing panel 110 can be separate from the
primary panels of the blank 100.
End flaps are hingedly connected to opposing edges of each primary
panel 102, 104, 106, 108 and to opposing edges of the reinforcing panel 110.
The blank 100 is substantially symmetric such that the end flaps that are
hingedly
connected to the opposite ends of each primary pane! are substantially
similar.
Accordingly, the end closure structures of the carton 200 are substantially
identical and like references have been used with a suffix "a" or "b" affixed
to
distinguish one end of the carton 200 from the other. Thus, the description of
an
element or group of elements having a suffix "a" can be applied to a like-
numbered element or group of elements having a suffix "b". In certain
instances,
for clarity, only one of the like elements is described unless a description
of the
other or both of the like elements is useful for understanding the invention.
Top end flaps 120a, 120b are hingedly connected to top panel 102 along
fold lines 122a, 122b, first side end flaps 124a, 124b are hingedly connected
to
first side panel 104 along fold lines 126a, 126b, bottom end flaps 128a, 128b
are
hingedly connected to bottom panel 106 along.fold lines 130a, 130b, and second
side end flaps 132a, 132b are hingedly connected to second side panel 108
along fold lines 134a, 134b. Further, reinforcing end flaps 136a, 136b are
connected to the reinforcing panel 110 by compression relief hinges 140a,
140b.
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Referring to FIGs. I and 2, the compression relief hinge 140a includes a
group of fold lines that define bulge panels. In the exemplary embodiment, the
compression relief hinge 140a includes an inner distal fold line 142a, a
medial
fold line 144a, and an outer distal fold line 146a. The fold lines 142a, 144a
define
a first bulge panel 148a and the fold lines 144a, 146a define a second bulge
panel 150a. It should be noted that the medial fold line 144a can include a
group
of adjacent substantially parallel weakened lines, as described in further
detail
below. The compression relief hinge 140a further includes apertures 152a that
interrupt the fold lines 142a, 144a, 146a so as to increasingly facilitate
buckling,
folding, or collapsing the compression relief hinge 140a, as described in
further
detail below.
The fold lines 142a, 144a, 146a are substantially parallel to one another
and are spaced from one another by a distance D1. In certain embodiments, the
distance D1 is a function of the thickness or caliper of the blank 100 or of
the
layers of sheet material that define a composite panel, as described in
further
detail below. The width of each of the bulge panels 148a, 150a is accordingly
substantially equal to the distance Dl.
As described in further detail below, the widths of the fold lines 142a,
144a, 146a can be selected to facilitate buckling of the compression relief
hinge
140a. It should be understood that wider fold lines are easier to buckle,
collapse,
or initiate a fold along. Typically, a single die is needed to form a fold
line, as
described in further detail below. To form a wider fold line, a group of dies
can be
used. In the exemplary embodiment, the width of the medial fold line 144a is
selected to be wider than the widths of the distal fold lines 142a, 146a.
Thereby,
folding or buckling is facilitated to a substantially greater degree along the
medial
fold line 144a than along the distal fold lines 142a, 146a.
In alternative embodiments, the compression relief hinge 140a includes
more than three fold lines and more than two bulge panels. For example, a
compression relief hinge can include two medial fold lines and two distal fold
lines
that define three bulge panels.
The carton 200 can be formed according to the following non-limiting
method. Referring to FIGs. 3 and 4, a tubular structure can first be formed by
at
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least partially securing the outside surface of the reinforcing panel 110 to
the
inside surface of the top panel 102. Further, the outside surfaces of the
reinforcing end flaps 136a, 136b are at least partially secured to the inside
surfaces of respective top end flaps 120a, 120b. The reinforcing panel 110 and
reinforcing end flaps 136a, 136b are secured to the primary panel 102 and the
primary end flaps 120a, 120b such that the fold lines 122a, 122b are aligned
with
the compression relief hinges 140a, 140b, respectively. Referring momentarily
to
FIG. 5, the fold line 122a is aligned with the compression relief hinge 140a
so as
to lie between the distal fold lines 142a, 146a. It should be noted that the
bulge
panels 148a, 150a are not secured to the top panel 102 or top end flap 120a.
Rather, the bulge panels 148a, 150a can move independently from the top panel
102 and the top end flap 120a.
Hereinafter the term "primary layer" refers to the layer of material defined
by or including the top panel 102 and the top end flap 120a and the term
"reinforcing layer" refers to the layer of material defined by or including
the
reinforcing panel 110 and reinforcing end flap 136a. Once secured together,
the
primary layer and the reinforcing layer define a foldable composite panel.
Further, the fold line 122a that is disposed in the primary layer is
hereinafter
referred to as the primary hinge along which the composite panel is folded.
In the exemplary embodiment, the inner surface of the primary layer is
secured to the reinforcing layer at two general locations on opposite sides of
the
compression relief hinge 140a.
As shown in FIGs. 3 and 4, the primary end flaps 120a, 124a, 128a, 132a
are folded and secured to form a first end wall of the carton 200.
Accordingly, the
composite panel is folded along the primary hinge 122a_ Consequently,
referring
to FIGs. 5-8, the compression relief hinge 140a portion of the reinforcing
layer is
compressed between the reinforcing panel 110 and the reinforcing end flap
136a.
In cartons without a compression relief hinge 140a, the material that makes up
the compression relief hinge 140a would gather, compress, and be forced
against
the inside surface of the area of the primary layer near the primary hinge
122a,
thereby resisting folding along the primary hinge 122a. However, the fold
lines
142a, 144a, 146a of the compression relief hinge 140a facilitate pivoting
movement of the bulge panels 148a, 160a, or otherwise folding, buckling,
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collapsing, flexing, or crumpling of the compression relief hinge 140a, such
that
folding resistance due to compression of the material of the compression
relief
hinge 140a portion of the reinforcing layer is relieved.
Referring to FIGs. 5 and 7, as the compression relief hinge 140a buckles,
it forms a furrow E. Specifically, the bulge panels 148a, 150a fold along the
medial fold line 144a and the distal fold lines 142a, 146a, the outside
surfaces of
the bulge panels 148a, 150a move toward one another, and the portion of the
reinforcing layer adjacent the medial fold line 144a moves away from the
corner
defined by the primary hinge 122a.
Methods of forming and arranging a group of fold lines to provide a
compression relief hinge are described in further detail. As used herein, the
term
"fold line" refers to all manner of lines that define hinge features of the
blank,
facilitate folding portions of the blank with respect to one another, or
otherwise
indicate optimal panel folding locations for the blank. A fold line is
typically a
scored line, an embossed line, or a debossed line. It should be understood
that
fold lines can each include elements that are formed in the substrate of the
blank
including perforations, a line of perforations, a line of short slits, a line
of half-cuts,
a single half-cut, a cut line, an interrupted cut line, slits, scores, any
combination
thereof, and the like. The elements can be dimensioned and arranged to provide
the desired functionality. For example, a line of perForations can be
dimensioned
or arranged to provide a fold line with a certain degree of weakness that may
be
greater than the weakness of a fold line formed from a scored line.
The fold lines 142a, 144a, 146a can be formed in the blank 100 by the
following non-limiting method to form the compression relief hinge 140a. It
should be understood that the fold lines 142a, 144a, 146a can be formed in the
blank 100 via any known or yet to be developed process, such as stamping or
scoring. In the exemplary embodiments, the fold lines are created with an
arrangement of tools, such as dies, where each die is for forming a weakened
line of a certain width and each fold line includes one or more weakened lines
formed by a corresponding number of dies.
It should be understood that the method described below is for forming an
alternative arrangement of a compression relief hinge that is illustrated in
FIG. 9.
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The embodiment of FIG. 9 and the embodiment of FIG. 7 are substantially
similar
with the exception that depressions that define the distai fold lines 142a,
146a are
formed in different sides or surfaces of the reinforcing layer in the
different
embodiments. It should be understood that the method described below can be
altered to produce the embodiment of FIG. 7, for example, by first forming the
medial fold line in a first surface of the blank and flipping the blank before
forming
the distal fold lines in a second surface of the blank.
Each die can include a relatively dull edge suitable for stamping an
impression, a relatively honed or sharp edge that makes a line of cuts in the
blank 100, or a combination of alternating dull and honed edges that create
alternating scores and cuts or half cuts. Referring to FIG. 9, an end view
shows
that one type of die 900 that can be used to form a weakened line that
alternates
between short slits and score lines and another type of die 902 can be used to
form a score line.
The exemplary arrangement or configuration of dies 900, 902 is used to
form the arrangement of fold lines 142a, 144a, 146a that define the
compression
relief hinge 140a. The distal fold lines 142a, 146a are formed with a single
die
900. The medial fold line 144a is formed with a group of three dies 900, 902,
where the outermost dies 900 form a weakened line that is a score line and the
centermost die 902 forms a comparatively weaker weakened line that alternates
between short slits and score lines. Accordingly the medial fold line 144a is
formed from three substantially parallel adjacent weakened lines and has three
times the width of the distal fold lines 142a, 146a. It should be understood
that,
according to the exemplary method, the number of dies that are used to form
each fold line determines the width of the fold line. The depths of the
weakened
lines, with respect to the surface of the layer of material, are determined by
the
force used to score the material and by the characteristics of the material.
The centers of the weakened lines of the medial fold line 144a are
disposed at substantially equal distances D3 from one another. The distance D2
between the center of a distal fold line 142a, 146a and the center of the
nearest
of the group of weakened lines that form the medial fold line 144a is greater
than
the distance D3 between the weakened lines of the medial fold line 144a.
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In alternative embodiments, the medial fold line 144a can be formed by
more than three dies. For example, a medial fold line can be formed with four
dies. For such a medial fold line, one or more of the centermost dies forms a
weakened line that alternates between short slits and score lines and the
remainder of the dies forms weakened lines that are score lines.
In additional alternative embodiments, configurations that form more that
three fold lines are contemplated. For example, a configuration of dies can
form
two medial fold lines inside of two distal fold lines.
To optimally control the direction of collapse, fold lines can be formed in
either side or surface of a reinforcing layer, or in both sides or surfaces of
a
reinforcing layer. For example, referring. again to FIGs. 7 and 8, the medial
fold
line 144a is formed in the outer side or surface of the reinforcing layer and
the
distal fold lines 142a, 146a can be formed in the inner side or surface of the
reinforcing layer. In contrast, FIG. 9 shows an alternative arrangement
wherein
the medial fold line 144a is formed in the inner side or surface of the
reinforcing
layer. In the configuration shown in FIGs. 7 and 8, the fold lines 142a, 144a,
146a are formed in a side of the reinforcing layer such that as the
compression
relief hinge 140a folds or buckles, the channels, impressions, or cavities
defined
by the fold lines 142a, 144a, 146a collapse to provide compression relief.
The present invention has been illustrated in relation to a particular
embodiment which is intended in all respects to be illustrative rather than
restrictive. Those skilled in the art will recognize that the present
invention is
capable of many modifications and variations without departing from the scope
of
the invention. For example, as used herein, directional references such as
"top",
"base", "bottom", "end", "side", "inner", "outer", "upper", "middle", "lower",
"front"
and "rear" do not limit the respective walls of the carton to such
orientation, but
merely serve to distinguish these walls from one another. Any reference to
hinged connection should not be construed as necessarily referring to a
junction
including a single hinge only; indeed, it is envisaged that hinged connection
can
be formed from one or more potentially disparate means for hingedly connecting
materials.
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The above-described embodiments are merely exemplary illustrations of
implementations set forth for a clear understanding of the principles of the
invention.. Variations, modifications, and combinations may be made to the
above-described embodiments without departing from the scope of the claims.
All such variations, modifications, and combinations are included herein by
the
scope of this disclosure and the following claims.
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