U.S. patent application number 13/186809 was filed with the patent office on 2013-01-24 for apparatus and method for aligning and holding egg cartons.
This patent application is currently assigned to Tekni-Plex, Inc.. The applicant listed for this patent is Mark A. Bergeron, Richard L. Ramirez. Invention is credited to Mark A. Bergeron, Richard L. Ramirez.
Application Number | 20130020224 13/186809 |
Document ID | / |
Family ID | 47555033 |
Filed Date | 2013-01-24 |
United States Patent
Application |
20130020224 |
Kind Code |
A1 |
Ramirez; Richard L. ; et
al. |
January 24, 2013 |
APPARATUS AND METHOD FOR ALIGNING AND HOLDING EGG CARTONS
Abstract
Egg carton and method for transporting filled egg cartons that
enables ready stacking of multiple cartons, one filled carton on
top of another, for stable transport with or without the use of
exterior containers for holding together the stack as are typically
used in the industry.
Inventors: |
Ramirez; Richard L.;
(Lawrenceville, GA) ; Bergeron; Mark A.; (Monroe,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ramirez; Richard L.
Bergeron; Mark A. |
Lawrenceville
Monroe |
GA
GA |
US
US |
|
|
Assignee: |
Tekni-Plex, Inc.
King of Prussia
PA
|
Family ID: |
47555033 |
Appl. No.: |
13/186809 |
Filed: |
July 20, 2011 |
Current U.S.
Class: |
206/521.8 ;
29/428 |
Current CPC
Class: |
B65D 85/32 20130101;
B65D 21/0219 20130101; Y10T 29/49826 20150115; B65D 21/0209
20130101; B65G 57/02 20130101 |
Class at
Publication: |
206/521.8 ;
29/428 |
International
Class: |
B65D 85/32 20060101
B65D085/32 |
Claims
1. An egg carton comprising: a stackable egg carton of plastic
material having a lid and a tray hingedly connected to the lid,
said egg carton having a width and length; the tray having a
plurality of cells for receiving individual eggs, the cells being
arranged successively adjacent each other along the width and along
the length of the carton, each cell having an under-surface forming
a bottom of the tray, the under-surface of the cells forming a
series of recesses between adjacent cells; and a pair of bosses
projecting upwardly from an outer top surface of the lid, the pair
of bosses being arranged at opposing ends along the length or width
of the carton for positioning between two recesses of an adjacent
carton stacked on top thereof, wherein the two recesses restrict
movement of the bosses for maintaining the cartons in a stacked
configuration.
2. The carton of claim 1, wherein the lid has a trough that extends
between the bosses.
3. The carton of claim 2, wherein the trough extends up to and
terminates at the bosses.
4. The carton of claim 2, wherein the trough has a width that is
about the same as a width of the bosses.
5. The carton of claim 1, wherein the bosses have an upper surface
contour that is complementary to a contour of the two recesses to
resist lateral and/or longitudinal movement of the cartons relative
to each other.
6. The carton of claim 1, wherein the pair of bosses is disposed at
about the centerline of the length or of the width of the
carton.
7. The carton of claim 6, wherein the bosses are arranged along or
adjacent the opposing lengthwise or widthwise edges of the
carton.
8. The carton of claim 1, wherein the bosses are disposed beyond
the lengthwise or widthwise edges of the lid and are supported by
angled portions of a lid sidewall.
9. The carton of claim 1, wherein the bosses are arranged along or
adjacent the lengthwise edges of the carton.
10. The carton of claim 1, wherein the plastic comprises a
thermoplastic which is foamed or unfoamed, and comprises one or
more of polystyrene, polyester, polyolefin, and poly(lactic acid),
including homopolymers, copolymers, mixtures and blends thereof,
and including virgin and reclaimed materials.
11. The carton of claim 1, wherein the plastic comprises
polystyrene foam.
12. A stack comprising a plurality of stacked egg cartons as
described in claim 1.
13. The stack of claim 12, where the stack comprises at least four
layers of the cartons stacked one above the other.
14. The stack of claim 13, wherein the stack rests on a pallet.
15. The stack of claim 14, wherein the stack includes a stacking
sheet between every 4, 5 or 6 layers of cartons.
16. The stack of claim 12, wherein the stack is disposed on a
pallet for transport without exterior support to the stack.
17. The stack of claim 12, wherein the stack is disposed on a
pallet for transport with only an outer film wrap supporting the
stack.
18. A plastic egg carton for packaging a plurality of eggs, said
egg carton having a width and a length, the carton comprising: a
lid and a tray hingedly connected to the lid; the tray having a
plurality of cells for receiving individual ones of the eggs, the
cells being arranged successively adjacent each other along the
width and along the length of the carton, the lid having a top
surface and being pivotable around the hinged connection into a
closed position enclosing the cells, each cell having an
under-surface forming a bottom of the tray, the under-surface of
the cells forming a series of recesses between adjacent cells, the
top surface of the lid having a pair of bosses projecting upwardly
from the top surface of the lid, the pair of bosses being arranged
at opposing ends along the length or width of the carton; the
bosses having an upper surface contour that is complementary to a
selected contour of at least two recesses on the bottom, the at
least two complementary recesses being arranged on the bottom for
simultaneous receipt of a pair of bosses on the lid of a carton
when the lid is in a dosed position; wherein when the pair of
bosses are received within the at least two complementary recesses
on the bottom of another one of the cartons, the complementary
contours of the bosses and recesses resist lateral and/or
longitudinal movement of the cartons relative to each other.
19. The egg carton of claim 18, wherein the tray comprises a
2.times.6, 3.times.6, 4.times.6, 5.times.6 or 6.times.6 matrix of
cells.
20. The egg carton of claim 18, wherein the plastic comprises a
thermoplastic which is foamed or unfoamed, and comprises one or
more of polystyrene, polyester, polyolefin and poly(lactic acid),
including homopolymers, copolymers, mixtures and blends thereof,
and including virgin and reclaimed materials.
21. The egg carton of claim 18, wherein the plastic comprises
polystyrene foam.
22. The egg carton of claim 18, wherein the lid comprises a
generally planar sheet having a trough formed in the sheet that
extends between the bosses.
23. The egg carton of claim 22, wherein the trough extends up to
and terminates at the bosses.
24. A method of stacking plastic egg cartons one on top of the
other, each egg carton having a length and a width and comprising a
lid and a tray hingedly connected to the lid; the tray having a
plurality of cells for receiving individual eggs, the cells being
arranged successively adjacent each other along the width and along
the length of the carton, each cell having an under-surface forming
a bottom of the tray, the under-surface of the cells forming a
series of recesses between adjacent cells on the bottom of the
tray, a pair of bosses having a selected upper surface contour
above a top surface of the lid such that the bosses project
upwardly from the top surface of the lid, the pair of bosses being
arranged at opposing positions disposed along the length or width
of the carton, the method comprising: stacking one carton on top of
another carton such that the two complementary recesses on the
bottom of the one carton each receive one of the pair of bosses on
the top surface of the lid of the other carton.
25. The method of claim 24, wherein the pair of bosses and the two
complementary recesses are disposed at about the centerline of the
width or length of the carton.
26. The method of claim 24, wherein the pair of bosses have a size
and configuration such that when the pair of bosses are received
within the recesses on the bottom of another one of the cartons,
lateral and/or longitudinal movement of the cartons relative to
each other is restricted.
27. The method of claim 24, wherein the bosses are disposed at
about the centerline of the length or width of the carton.
28. The method of claim 24, wherein the bosses are arranged along
or adjacent the lengthwise or widthwise edges of the carton.
29. The method of claim 24, including transporting the stacked
cartons.
30. The method of claim 24, including transporting the stacked
cartons on a pallet.
31. The method of claim 24, including transporting the stacked
cartons on a pallet without providing exterior support to the
stack.
32. The method of claim 24, including transporting the stacked
cartons on a pallet with only an outer film wrap supporting the
stacked cartons.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to plastic egg cartons and
more particularly to an egg carton having features that enable
aligning and stacking multiple cartons for transport.
BACKGROUND
[0002] Many factors are taken into consideration in the design of
egg cartons. Egg protection, stackability, transportability,
aesthetic appearance, print surface area, strength, weight,
nestability/denestability, adaptability to accommodate various size
eggs, and consistent manufacturing are factors which may be
considered to varying degrees in the design of an egg carton.
[0003] Polystyrene egg cartons are formed and trimmed from a single
sheet of polystyrene foam material to integrally define a lid and a
tray connected by a hinged area. The formed egg cartons are
transported, typically by conveyer belt, to a printing machine and
imprinted with an egg distributor's trade style, government
mandated nutritional information, and retail information, such as
UPC labels. The egg cartons are then nested one within another and
packaged in bags or pallets for shipping to egg distributors. The
distributor then fills the cartons with eggs at a filling station
and transports the filled cartons to another location. The process
of transport of filled egg cartons requires that cartons first be
stacked in a stable arrangement such that when physically moved on
a pallet the multitude of stacked, filled cartons are transportable
without risk of falling off the pallet, falling out of the stacked
arrangement, and/or otherwise moving or collapsing so as to cause
damage to the eggs.
SUMMARY OF THE INVENTION
[0004] The present invention provides a plastic egg carton and a
method for aligning and stacking filled egg cartons, one filled
carton on top of another, for stable transport without requiring
the use of additional packaging, such as corrugated cases, wire or
plastic baskets, or the like. By keeping the stacked cartons
squarely aligned without the need for master containers, the
invention reduces overall packaging cost, waste, and protects
fragile eggs. The new carton is suited for direct pallet stacking,
such as on grocery pallets 40''.times.48'', optionally with slip
sheets between every 4, 5 or 6 layers, enabling the cartons to be
stacked 20 to 25 cartons high.
[0005] The new cartons can, if desired, be packaged or otherwise
supported in, for example, existing standard master corrugated
containers (e.g., full or half case), plastic or wire baskets,
carts, wrapped in film or the like.
[0006] In one embodiment, a pair of contoured bosses are provided
on the lid top, disposed on opposite ends of a centerline of the
carton, either widthwise or lengthwise, to restrict movement of
adjacent cell bottoms (of an adjacent carton). The height of the
lid bosses can be adjusted, with for example a minimum height of
3/16'' being effective to securely hold a weighted carton stack on
top (e.g., 20 to 25 cartons high). The cartons may be made of
polystyrene foam, of dimensions and thickness that are standard in
the industry.
[0007] In accordance with one embodiment of the invention, an egg
carton is provided comprising a stackable egg carton of plastic
material having a lid and a tray hingedly connected to the lid,
said egg carton having a width and length;
[0008] the tray having a plurality of cells for receiving
individual eggs, the cells being arranged successively adjacent
each other along the width and along the length of the carton,
[0009] each cell having an under-surface forming a bottom of the
tray, [0010] the under-surface of the cells forming a series of
recesses between adjacent cells; and [0011] a pair of bosses
projecting upwardly from an outer top surface of the lid, the pair
of bosses being arranged at opposing ends along the length or width
of the carton for positioning between two recesses of an adjacent
carton stacked on top thereof, wherein the two recesses restrict
movement of the bosses for maintaining the cartons in a stacked
configuration.
[0012] According to one embodiment of the invention, the lid has a
trough that extends between the bosses.
[0013] According to one embodiment of the invention, the trough
extends up to and terminates at the bosses.
[0014] According to one embodiment of the invention, the trough has
a width that is about the same as a width of the bosses.
[0015] According to another embodiment of the invention, the bosses
have an upper surface contour that is complementary to a contour of
the two recesses to resist lateral and/or longitudinal movement of
the cartons relative to each other.
[0016] According to one embodiment of the invention, the pair of
bosses is disposed at about the centerline of the length or of the
width of the carton.
[0017] According to one embodiment of the invention, the bosses are
arranged along or adjacent the opposing lengthwise or widthwise
edges of the carton.
[0018] According to one embodiment of the invention, the bosses are
disposed beyond the lengthwise or widthwise edges of the lid and
are supported by angled portions of a lid sidewall.
[0019] According to one embodiment of the invention, the bosses are
arranged along or adjacent the lengthwise edges of the carton.
[0020] According to one embodiment of the invention, the plastic
comprises a thermoplastic which is foamed or unfoamed, and
comprises one or more of polystyrene, polyester, polyolefin, and
poly(lactic acid), including homopolymers, copolymers, mixtures and
blends thereof, and including virgin and reclaimed materials.
[0021] According to one embodiment of the invention, the plastic
comprises polystyrene foam.
[0022] According to one embodiment of the invention, a stack is
provided comprising a plurality of stacked egg cartons.
[0023] According to one embodiment of the invention, where the
stack comprises at least four layers of the cartons stacked one
above the other.
[0024] According to one embodiment of the invention, the stack
rests on a pallet.
[0025] According to one embodiment of the invention, the stack
includes a stacking sheet between every 4, 5 or 6 layers of
cartons.
[0026] According to one embodiment of the invention, the stack is
disposed on a pallet for transport without exterior support to the
stack.
[0027] According to one embodiment of the invention, the stack is
disposed on a pallet for transport with only an outer film wrap
supporting the stack.
[0028] In accordance with another embodiment of the invention, a
plastic egg carton is provided for packaging a plurality of eggs,
said egg carton having a width and a length, the carton comprising:
[0029] a lid and a tray hingedly connected to the lid; [0030] the
tray having a plurality of cells for receiving individual ones of
the eggs, the cells being arranged successively adjacent each other
along the width and along the length of the carton, [0031] the lid
having a top surface and being pivotable around the hinged
connection into a closed position enclosing the cells, [0032] each
cell having an under-surface forming a bottom of the tray, the
under-surface of the cells forming a series of recesses between
adjacent cells, [0033] the top surface of the lid having a pair of
bosses projecting upwardly from the top surface of the lid, the
pair of bosses being arranged at opposing ends along the length or
width of the carton; [0034] the bosses having an upper surface
contour that is complementary to a selected contour of at least two
recesses on the bottom, the at least two complementary recesses
being arranged on the bottom for simultaneous receipt of a pair of
bosses on the lid of a carton when the lid is in a closed position;
[0035] wherein when the pair of bosses are received within the at
least two complementary recesses on the bottom of another one of
the cartons, the complementary contours of the bosses and recesses
resist lateral and/or longitudinal movement of the cartons relative
to each other.
[0036] According to one embodiment of the invention, the tray
comprises a 2.times.6, 3.times.6, 4.times.6, 5.times.6 or 6.times.6
matrix of cells.
[0037] According to one embodiment of the invention, the plastic
comprises a thermoplastic which is foamed or unfoamed, and
comprises one or more of polystyrene, polyester, polyolefin and
poly(lactic acid), including homopolymers, copolymers, mixtures and
blends thereof, and including virgin and reclaimed materials.
[0038] According to one embodiment of the invention, the plastic
comprises polystyrene foam.
[0039] According to one embodiment of the invention, the lid
comprises a generally planar sheet having a trough formed in the
sheet that extends between the bosses.
[0040] According to one embodiment of the invention, the trough
extends up to and terminates at the bosses.
[0041] In accordance with another embodiment of the invention, a
method of stacking plastic egg cartons one on top of the other is
provided, each egg carton having a length and a width and
comprising a lid and a tray hingedly connected to the lid; the tray
having a plurality of cells for receiving individual eggs, the
cells being arranged successively adjacent each other along the
width and along the length of the carton, each cell having an
under-surface forming a bottom of the tray, the under-surface of
the cells forming a series of recesses between adjacent cells on
the bottom of the tray, a pair of bosses having a selected upper
surface contour above a top surface of the lid such that the bosses
project upwardly from the top surface of the lid, the pair of
bosses being arranged at opposing positions disposed along the
length or width of the carton, the method comprising: [0042]
stacking one carton on top of another carton such that the two
complementary recesses on the bottom of the one carton each receive
one of the pair of bosses on the top surface of the lid of the
other carton.
[0043] In accordance with one embodiment of the invention, the pair
of bosses and the two complementary recesses are disposed at about
the centerline of the width or length of the carton.
[0044] In accordance with one embodiment of the invention, the pair
of bosses have a size and configuration such that when the pair of
bosses are received within the recesses on the bottom of another
one of the cartons, lateral and/or longitudinal movement of the
cartons relative to each other is restricted.
[0045] In accordance with one embodiment of the invention, the
bosses are disposed at about the centerline of the length or width
of the carton.
[0046] In accordance with one embodiment of the invention, the
bosses are arranged along or adjacent the lengthwise or widthwise
edges of the carton.
[0047] In accordance with one embodiment of the invention, the
method includes transporting the stacked cartons.
[0048] In accordance with one embodiment of the invention, the
method includes transporting the stacked cartons on a pallet.
[0049] In accordance with one embodiment of the invention, the
method includes transporting the stacked cartons on a pallet
without providing exterior support to the stack.
[0050] In accordance with one embodiment of the invention, the
method includes transporting the stacked cartons on a pallet with
only an outer film wrap supporting the stacked cartons.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] The drawings depict various embodiments of the invention
wherein:
[0052] FIG. 1 is a top left perspective view of a 4.times.6 matrix
egg carton according to one embodiment of the invention showing the
lid closed over on top of the bottom tray portion that receives the
eggs;
[0053] FIG. 2 is top plan view of the FIG. 1 carton;
[0054] FIG. 3 is a front view of the FIG. 1 carton;
[0055] FIG. 4 is a back view of the FIG. 1 carton;
[0056] FIG. 5 is a side view of the FIG. 1 carton;
[0057] FIG. 6 is bottom plan view of the FIG. 1 carton;
[0058] FIG. 7 is a front view of three FIG. 1 cartons stacked one
on top of each other;
[0059] FIG. 8 is a sectional view taken along lines 8-8 of FIG.
7;
[0060] FIG. 9 is a sectional view taken along lines 9-9 of FIG.
8;
[0061] FIG. 10 is a side view of a pallet of stacked FIG. 1 cartons
showing a crane depositing another group of stacked FIG. 1 cartons
on top of the stack already on the pallet;
[0062] FIG. 11 is a side view of a stack of cartons wrapped in film
on a pallet;
[0063] FIG. 12 is a perspective view of an alternative embodiment
of an egg carton wherein the outer edges of the bosses reside
beyond the edge of the lid top wall; and
[0064] FIG. 13 is a sectional view showing a boss of the carton of
FIG. 12 engaging a cell of an adjacent carton.
DETAILED DESCRIPTION
[0065] FIG. 1 shows in perspective view an egg carton 10 according
to one embodiment of the invention. The carton 10, having general
overall dimensions of length L, width W and height H, is comprised
of a lid 20 connected via a hinge 12 to a base tray 30, the tray
comprising a plurality of egg receiving cells 40 arranged in a
matrix. The carton 10 is typically integrally molded from a sheet
of polystyrene foam which is formed into an end product having the
components described herein via conventional molding processes,
e.g., pressing a foam sheet between male and female dies to form
shaped lid and base portions and then removing (trimming) any
remaining portions of the sheet to form an integral carton. The
formation and structure of components such as the hinge 12, base
locking nubs 14, associated lid flap and locking apertures 16,
cells 40 and the like are shown and described in the prior art such
as in U.S. Pat. No. 6,012,583 and U.S. Pat. No. 5,494,164 the
disclosures of which are incorporated herein by reference as if
fully set forth herein.
[0066] As shown in FIGS. 1-2 the lid 20 has a generally flat
(planar) upper surface 21 and a peripheral sidewall 23 extending
downwardly to a peripheral lower edge 25 that mates with a
peripheral upper edge 27 of the base tray. The lid 20 top wall is
molded to include a recessed trough 50 disposed at and along a
centerline C1 transverse to length L of the carton 10. A pair of
bosses 70 are provided, one at each end of the trough 50, the
bosses having a preselected contour, e.g., size, shape, height P,
geometry and/or configuration. The bosses are formed in the lid 20
as protrusions that extend axially A above the planar surface 21 of
the lid 20 by a distance P (see FIG. 5) which is preferably a
minimum of about 3/16 inches.
[0067] The elongated trough 50 is disposed along the width W of the
carton between the bosses 70, and in the embodiment shown, the ends
of the trough 50 terminate in the bosses 70 which, as shown, are
disposed with their outermost edges 76 adjacent the lengthwise
edges 22 of the lid 20. The trough 50 is formed within the body of
the lid 20 as a generally elongated rectangular depression within
the body of the planar surface 21 having elongated continuous walls
51 that extend axially A downwardly and below the planar surface 21
by a distance T, (see FIG. 1), in the opposite axial direction from
the upward axial distance of projection P of bosses 70 (see FIG.
5). The walls 51 of the trough 50 preferably extend axially
downwardly toward the tray 30 a sufficient distance T to enable the
walls 51 to reinforce the lid and/or to laterally engage and act as
a barrier or wall to protect eggs that are deposited within those
cells 136, 138 that are immediately adjacent the lengthwise
centerline C1 (or widthwise centerline C2 if the trough is aligned
along the length) of the tray. Thus by extending a sufficient
distance T from the top 21 downwardly toward the tray 30, the walls
51 can reinforce the lid (increase the mechanical strength of the
carton), and in particular reinforce the bosses (to facilitate
stacking without undue movement of the cartons with respect to one
another) and/or engage and prevent eggs in the two rows of cells
immediately adjacent the centerline (C1) from moving laterally
within the tray 30. As shown, the bosses 70 are disposed at and
along about the centerline C1 of the length of the carton 10.
Alternatively, the bosses 70 and the trough 50 could be formed and
disposed at and along about the centerline C2 of the width W of the
carton 10, the location of such bosses 70a being shown in schematic
in FIG. 2. In such an embodiment, the trough 50 can be formed in
and extend between bosses 70a along the centerline C2 of the width
W.
[0068] As shown the tray portion 30 of the carton 10 comprises a
series of egg receiving cells 40 each formed to receive and
accommodate a single egg. Each of the cells 40 is formed with a
side wall 139 (see FIG. 8) having an inner receiving surface 140
contoured to receive the ovoid shape of an egg. The side wall 139
extends upwardly to define an open top and, where there is an
adjoining cell joins with the sidewall 139 of the adjoining cell
106, with the two side walls 139 cooperatively defining a cell
junction 142 (see FIG. 8). The cell junction 142 has generally at
least one rounded shoulder which blends into a raised upper edge.
The upper edge is flexible to respond to pressure applied by
packaged eggs and provides protection therefor. Prerably, the
carton comprises an even number of cells (for example 2, 4, 6, 8,
10, 12, etc.) serially interconnected either widthwise or
lengthwise such that the bosses 70 or 70a can be positioned at
about the center line or point between two adjacent cells while
simultaneously being disposed at about the centerline C1 or C2 of
either the length L or width W of the carton 10 along which an even
number of cells are serially interconnected in a straight sequence.
In the embodiment shown in FIGS. 1-10, the carton 10 comprises 6
rows of 4 cells extending along the width W, or 4 rows of 6 cells
extending along the length L of the carton 10. Typical other cell
matrix formats are 2.times.4, 3.times.6, 3.times.4, 4.times.4,
4.times.6, 5.times.6 and 6.times.6. By way of example only, the
polystyrene foam 4.times.6 matrix carton shown in FIGS. 1-10 is
designed to hold 24 extra large eggs, and is about 8 inches in
width, about 115/8 inches in length, and about 2% inches in height;
each boss is about 1 inch long and about 11/2 inch wide and about
3/16 inches deep; the trough is about 53/4 inches long and about
3/4 inches wide (at the top end) and about 11/8 inches deep; the
base tray is about 11/2 inches deep; the lid is about 11/2 inches
deep; and each cell (at the top edge) is about 17/8 inches in
length and 17/8 in width. This is given by way of example only and
is not meant to be limiting.
[0069] As shown in FIG. 6, the carton 10 has corner cells 135,
exterior cells 138 and interior cells 136, the exact positioning of
which results in recesses 175, 176, 178 formed between the exterior
surfaces of the cells 135, 136, 138 on the bottom face 90 of the
carton 10 having configurations peculiar to the precise position of
the various cells 135, 136, 138. Generally, the contour of the
bottom outside cell surfaces 155, 156, 158 (of cells 135, 138, 136
respectively) are similar to each other such that the recesses 175,
176, 178 formed between adjacent cell outside surfaces 155, 156,
158 are similar in contour.
[0070] The contour of the upper or outside surfaces of the bosses
70, 70a (e.g., the size, shape, height, width, depth and/or
configuration of the bosses 70 or 70a) are selected and formed to
be complementary to the contour of at least two of the recesses
175, 176, 178 such that each of the bosses 70 or 70a can be readily
inserted into a recess. Preferably, the contour of the bosses 70,
70a are formed to be complementary to the contour of those recesses
that are formed between the outside surfaces of two adjacent
outside cells 138, and more particularly the recesses 178 that are
formed between the adjacent sidewall surfaces 158a of two adjacent
exterior cells 138 that are also disposed immediately adjacent or
straddle the centerline C1 of the length L (or C2 of the width W)
of the carton 10 along an outer lengthwise edge 13 (or widthwise
edge 17) of the tray 10. FIG. 2 shows this arrangement, where the
arcuate sidewall contours 70c of the bosses are aligned to engage
the outer circular contours of the two adjacent exterior cell
sidewalls 138 to resist longitudinal and lateral movement
therebetween. In this embodiment, the four corners 71, 72, 73, 74
(see FIG. 2) of the boss 70 provide four potential points of
engagement with the adjacent cells 158 (defining the recess 178) to
effectively limit/resist both longitudinal and lateral movement
between the stacked cartons.
[0071] This is further illustrated in FIGS. 7-9 where the two
bosses 70 (or 70a) are formed and disposed in predetermined
positions on the top surface 21 of the lid 20 that match and are
complementary in position to the positions on the bottom 90 of the
carton 10 of at least two recesses, such as recesses 178a1 and
178a2. By such complementary positioning of at least two recesses
178a1 and 178a2, the two bosses 70 (or 70a) can be readily inserted
into these two recesses such that one carton 10u can be stacked on
top of another 10l carton (as shown in FIG. 7) rendering the two
cartons aligned and resistant to lateral LAT and/or longitudinal
LONG movement relative to each other by virtue of the two separate
bosses 178a1, 178a2 being engaged or engageable against the bottom
outside surfaces 158a1, 158a2 of the adjacent cells 138a1, 138a2
that form the recesses when the two stacked cartons 10u, 10l are
moved laterally LAT and/or longitudinally LONG relative to each
other.
[0072] In alternative embodiments, one or more additional bosses
(in addition to the pair show in FIG. 1) may be provided to lie
within other recesses, between either exterior or interior cell
walls. Alternatively, the pair of bosses may be provided not on a
centerline. Preferably at least two bosses are provided adjacent or
along opposing side edges of the carton, either the lengthwise or
widthwise edges. In one embodiment, a first pair of bosses is
provided adjacent or along the lengthwise edges and a second pair
of bosses is provided adjacent or along the widthwise edges.
[0073] As shown in FIGS. 8-9, the outside surface contour of the
bosses 70 (or 70a) is smooth and is preferably formed with sloped
outer surfaces 70c and/or smooth curvilinear or curved outer edges
70d that are configured so as to readily slide against the bottom
outside surfaces 158, 158a of the cells if and when the boss
surfaces 70c, 70d may come into contact with the outside surfaces
158, 158a of the cells 178, particularly when the bottom 90 of one
carton 10u is mechanically positioned above and lowered onto the
top side of another carton 10l. During such stacking and lowering
process the user/operator (and/or machine) performing the stacking
will attempt to mechanically align the bosses 70 (or 70a) with the
recesses 178a1, 178a2 for insertion of the bosses 70 (or 70a)
within a pair of complementarily positioned recesses, 178a1, 178a2.
Such mechanical alignment by the user cannot be perfect and the
sloped, curved and curvilinear surfaces 70c, 70d, 158, 158a serve
to facilitate insertion of the bosses into the complementary
recesses and thus result in better longitudinal and lateral
alignment of two cartons 10u, 10l during the stacking process.
[0074] The side wall 139 in each of the cells extends downwardly to
a base wall 144. In one embodiment, the base wall 144 is formed
with a flat interior bottom surface 150 and a flat annular exterior
bottom surface 152, the annular surface 152 having a central raised
button portion 154 defined therein (see FIG. 9). The raised button
portion 154 may be formed by densifying the polystyrene material of
the base wall 144. The cells 135, 136, 138 are collectively formed
such that the exterior bottom surfaces 152 of all of the cells 135,
136, 138 of one carton 10u are substantially co-planar to form a
substantially stable planar bottom surface PB (see FIG. 7), that
can readily engage and mate with the flat planar top surface 21 of
another carton 10l when the one carton 10l is mechanically stacked
or deposited on top of another carton 10u. By force of gravity G
(see FIG. 9), the bottom surfaces 152 bear against top surface 21
to provide a degree of stability against lateral LAT and
longitudinal LONG movement due to friction between surface 21 and
surfaces 152.
[0075] To provide further stability against lateral LAT and/or
longitudinal LONG movement, the bosses 70 (or 70a) most preferably
are formed with an outside upper surface contour that are
complementary (conform) to the contour of the complementary
recesses 178a1, 178a2 into which the bosses are intended to be
inserted. Such complementary contouring of the bosses to the
intended complementary recesses enables the bosses to project into
and reside within the depth of the complementary recesses when the
bottom surfaces 152 of the bases 144 of the cells 135, 136, 137
engage the top surface 21. If and when a carton 10u moves laterally
LAT or longitudinally LONG relative to carton 10l, the outside
surfaces 70c, 70d of the bosses will contact, engage and interfere
with the bottom outside surfaces 158, 158a of the cells 178 thus
preventing the upper stacked carton 10u from moving or otherwise
becoming not aligned on top of the lower disposed carton 10l. As
shown in FIGS. 7-9, surfaces 70c are formed to be complementary in
contour to the surfaces 158a, surfaces 70c having a partial
egg-shape similar to the partial egg-shape of surfaces 158a.
[0076] As shown in FIG. 10, in one embodiment a method and system
is provided for stacking cartons 10 on the top planar surface 210
of a readily transportable pallet 200 (typically via forklift or
crane 300) without the necessity of enclosing the stacked cartons
10, 10l, 10u within a container such as a box or cage or the like.
As shown, the cartons 10 are stacked vertically in series in direct
top 21 to bottom PB contact with each other, one on top of each
other in collective depths of preferably 3-6 cartons. Slip sheets
250 are preferably disposed between stacks of 3-6 cartons in
vertical depth. The slip sheets 250 typically comprise a flexible
sheet of paper, plastic or cloth that can be deposited on top of
and extend across the top surfaces 21 of a horizontal layer of
multiple side-by-side horizontally arranged cartons 400, typically
anywhere from about 2 to about 10 cartons horizontally across. As
described above, the coplanar bottom surfaces 152 of the cartons 10
form a planar bottom surface PB which collectively among multiple
cartons stacked at the same vertical level form a planar bottom PB2
such that when multiple cartons 10 are deposited side-by-side 400
on a slip sheet 250, the friction between PB2 and the slip sheet
250 provides an additional stability against lateral LAT and
longitudinal LONG movement relative to the cartons on which they
are stacked.
[0077] In another embodiment, shown in FIG. 11, a stack 410 of
cartons 10 is disposed on a pallet 412 and the stacked cartons are
wrapped in plastic film 414 (around the perimeter of the stack).
The film provides the only outer packaging supporting the stack of
egg cartons on the pallet.
[0078] The stackable egg cartons of the present invention can, if
desired, also be packaged in existing standard master corrugated
containers, such as one-half and full cases, plastic and wire
baskets, and carts. For example: (a) a corrugated paper container
(case), where a full case typically holds 30-dozen 2.times.6 egg
cartons, and a half case holds 15-dozen 2.times.6 egg cartons; (b)
plastic and metal grid baskets where each basket (a half case)
typically holds 15-dozen 2.times.6 egg cartons; (c) milk crates,
where each crate typically holds between 12-dozen jumbo 2.times.6
egg cartons (for jumbo size eggs) and 15-dozen regular egg cartons,
(for medium, large and/or extra large eggs); and (d) racks designed
to be wheeled or slid into grocery store display cases, where each
rack typically holds between 240 to 360 2.times.6 egg cartons.
[0079] In another alternative embodiment shown in FIGS. 12-13, an
egg carton 10' is the same as the egg carton 10 of FIG. 1, the only
difference being the pair of bosses 70' are moved outwardly along
the centerline C1 of the lid 20'. Here the outer edges 76' of the
bosses 70' reside beyond the lengthwise (or alternating widthwise)
edges 22' of the carton. As shown in FIGS. 12-13, the bosses 70'
are supported by an outwardly angled portion 24', extending away
from the upper lid surface 21', of the lid sidewall 23'. This
angled support portion 24' extends further toward the periphery of
the adjacent egg carton cell bottoms 158' to provide enhanced
support and stability. Here the more vertically disposed angled
portion 24' is disposed at a angle X of 172.degree. with respect to
the sidewall 23'.
[0080] In various embodiments, the plastic egg carton is made of a
thermoplastic which is foamed or unfoamed, and comprises one or
more of polystyrene, polyester (e.g., polyethylene terephithlate
(PET), polyolefin (e.g., polyethylene(PE), polypropylene(PP)), and
poly(lactic acid)(PLA), including homopolymers, copolymers,
mixtures and blends thereof, and including virgin and reclaimed
materials.
[0081] It is to be understood that the foregoing description is
intended to illustrate and not limit the scope of the
invention.
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