U.S. patent number 3,863,831 [Application Number 05/280,881] was granted by the patent office on 1975-02-04 for shipping carton.
This patent grant is currently assigned to International Paper Company. Invention is credited to Wilbur Wong, Roger M. Wozniacki.
United States Patent |
3,863,831 |
Wozniacki , et al. |
February 4, 1975 |
SHIPPING CARTON
Abstract
A shipping carton for ventilating and/or cooling the carton
contents during transit and/or cold storage comprising a body
section open at each end, closure means for each open end and means
attaching said closure means to the body section which wrap around
the outer surface of the body section adjacent each open end to
form on said body section a peripheral projection which defines on
the outer surface of the body section an area which is recessed
with respect to the projection. This recessed area is apertured in
order to ventilate and cool the contents of the carton. When a
plurality of the cartons are stacked for shipment, the peripheral
projections of adjoining cartons are aligned to thereby provide in
the stacked shipping arrangement interconnected vertical and
horizontal channels which extend throughout the shipping
arrangement. The recessed areas of adjoining cartons cooperate to
create these channels which surround the apertured portion of the
body section and thus communicate with the carton apertures.
Inventors: |
Wozniacki; Roger M. (Brea,
CA), Wong; Wilbur (Long Beach, CA) |
Assignee: |
International Paper Company
(New York, NY)
|
Family
ID: |
23074998 |
Appl.
No.: |
05/280,881 |
Filed: |
August 15, 1972 |
Current U.S.
Class: |
229/120; 217/40;
229/916; 217/42; 229/122.26; 426/419 |
Current CPC
Class: |
B65D
5/323 (20130101); B65D 85/34 (20130101); Y10S
229/916 (20130101) |
Current International
Class: |
B65D
5/00 (20060101); B65D 5/32 (20060101); B65D
85/34 (20060101); B65d 013/04 () |
Field of
Search: |
;229/23R,23BT,23A,6A,DIG.14,DIG.11,DIG.2 ;217/40,42 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
939,100 |
|
Oct 1963 |
|
GB |
|
1,517,934 |
|
Feb 1968 |
|
FR |
|
Primary Examiner: Price; William I.
Assistant Examiner: Garbe; Stephen P.
Attorney, Agent or Firm: Flynn; Lawrence W.
Claims
What is claimed is:
1. A carton open at its top for loading comprising a central body
section open at its top having a bottom panel and two side wall
panels attached to opposed edges of the bottom panel; end wall
panels at each end of the body section having attached thereto four
extension panels; a first extension panel joined to the outer
surface of the bottom panel in face-to-face relationship therewith,
second and third extension panels joined to the outer surfaces of
the two side wall panels in face-to-face relationship therewith;
the first extension panel disposed beneath the bottom edges of the
second and third extension panels with the second and third
extension panels resting on the first extension panel; a movable
fourth extension panel adapted to overlie the top edges of the
second and third extension panels; the extension panels joined to
the body section at each end thereof having between them an
apertured zone in the body section occupying about 33 to 75 percent
of the surface area of the body section.
2. The carton of claim 1 wherein the apertured zone occupies about
40 to 60 percent of the surface area of the body section.
3. The carton of claim 1 wherein the apertured zone occupies about
40 to 60 percent of the surface area of the body section and the
apertured area occupies about 10 to 25 percent of the surface area
of the apertured zone.
4. A carton open at its top for loading comprising a central body
section open at its top having a bottom panel, two side wall panels
attached to opposed edges of the bottom panel and at least one top
panel attached to a side wall panel, said at least one top panel
adapted to overlie the carton interior; end wall panels at each end
of the body section having attached thereto four extension panels;
a first extension panel joined to the outer surface of the bottom
panel in face-to-face relationship therewith, second and third
extension panels joined to the outer surfaces of the two side wall
panels in face-to-face relationship therewith; the first extension
panel disposed beneath the bottom edges of the second and third
extension panels with the second and third extension panels resting
on the first extension panel; a movable fourth extension panel
adapted to overlie said at least one top panel and top edges of the
second and third extension panels; the extension panels joined to
the body section at each end thereof having between them an
apertured zone occupying about 33 to 75 percent of the surface area
of the body section.
5. The carton of claim 4 wherein a top panel is attached to each
side wall panel.
6. The carton of claim 4 wherein a top panel is attached to each
side wall panel, said top panels adapted to cover in combination
only a portion of the top of the carton.
7. The carton of claim 4 wherein the apertured zone occupies about
40 to 60 percent of the surface area of the body section and the
apertured area occupies about 10 to 25 percent of the surface area
of the apertured zone.
8. A top loading carton comprising a central body section open at
its top having a bottom panel and two side wall panels attached to
opposed edges of the bottom panel; end wall panels at each end of
the body section having attached thereto four extension panels; a
first extension panel joined to the outer surface of the bottom
panel in face-to-face relationship therewith, second and third
extension panels joined to the outer surfaces of the two side wall
panels in face-to-face relationship therewith; the first extension
panel disposeod beneath the bottom edges of the second and third
extension panels with the second and third extension panels resting
on the first extension panel; a fourth extension panel resting on
the top edges of the second and third extension panels; the four
extension panels forming at each end of the body section an
exterior band about the periphery of the body section, the bands
defining between them a recessed apertured zone about the periphery
of the body section; said recessed zone occupying about 33 to 75
percent of the surface area of the body secction.
9. The carton of claim 8 wherein the recessed apertured zone
occupies about 40 to 60 percent of the surface area of the body
section.
10. The carton of claim 8 wherein the recessed apertured zone
occupies about 40 to 60 percent of the surface area of the body
section and the apertured area occupies about 10 to 25 percent of
the surface area of the apertured zone.
11. A stacking arrangement comprising a plurality of cartons, as
individually described in claim 10, said cartons disposed in an
arrangement wherein the exterior bands of a carton abut the
exterior bands of one or more adjoining cartons to provide channels
in the arrangement communicating with the apertured recessed zone
of the central body section of the cartons.
12. A top loading carton comprising a central body section having a
bottom panel, two side wall panels attached to opposed edges of the
bottom panel and at least one top panel attached to a side wall
panel along only one edge; end wall panels at each end of the body
section having attached thereto four extension panels; a first
extension panel joined to the outer surface of the bottom panel in
face-to-face relationship therewith, second and third extension
panels joined to the outer surfaces of the two side wall panels in
face-to-face relationship therewith; the first extension panel
disposed beneath the bottom edges of the second and third extension
panels with the second and third extension panels resting on the
first extension panel; a fourth extension panel overlying the said
at least one top panel and resting on the top edges of the second
and third extension panels; the four extension panels forming at
each end of the body section an exterior band about the periphery
of the body section, the bands defining between them a recessed
apertured zone about the periphery of the body section; said
recessed zone occupying about 33 to 75 percent of the surface area
of the body section.
13. The carton of claim 12 wherein a top panel is attached to each
side wall panel.
14. The carton of claim 12 wherein a top panel is attached to each
side wall panel, said at least one top panel covering only a
portion of the top of the carton.
15. A stacking arrangement comprising a plurality of cartons, as
individually described in claim 14, said cartons disposed in an
arrangement wherein the exterior bands of a carton abut the
exterior bands of one or more adjoining cartons to provide channels
in the arrangement communicating with the apertured recessed zone
of the central body section of the cartons.
16. The carton of claim 12 wherein the recessed apertured zone
occupies about 40 to 60 percent of the surface area of the body
section.
17. A stacking arrangement comprising a plurality of cartons, as
individually described in claim 16, said cartons disposed in an
arrangement wherein the exterior bands of a carton abut the
exterior bands of one or more adjoining cartons to provide channels
in the arrangement communicating with the apertured recessed zone
of the central body section of the cartons.
18. The carton of claim 12 wherein the apertured area occupies
about 10 to 50 percent of the surface area of the recessed
apertured zone.
19. The carton of claim 12 wherein the recessed apertured zone
occupies about 40 to 60 percent of the surface area of the body
section and the apertured area occupies about 10 to 25 percent of
the surface area of the apertured zone.
20. A stacking arrangement comprising a plurality of cartons, as
individually described in claim 19, said cartons disposed in an
arrangement wherein the exterior bands of a carton abut the
exterior bands of one or more adjoining cartons to provide channels
in the arrangement communicating with the apertured recessed zone
of the central body section of the cartons.
21. The carton of claim 12 wherein the extension panels are
adhesively joined to the body section.
22. A stacking arrangement comprising a plurality of cartons, as
individually described in claim 21, said cartons disposed in an
arrangement wherein the exterior bands of a carton abut the
exterior bands of one or more adjoining cartons to provide channels
in the arrangement communicating with the apertured recessed zone
of the central body section of the cartons.
23. A stacking arrangement comprising a plurality of cartons, as
individually described in claim 8, said cartons disposed in an
arrangement wherein the exterior bands of a carton abut the
exterior bands of one or more adjoining cartons to provide channels
in the arrangement communicating with the apertured recessed zone
of the central body section of the cartons.
24. A stacking arrangement comprising a plurality of cartons, as
individually described in claim 12, said cartons disposed in an
arrangement wherein the exterior bands of a carton abut the
exterior bands of one or more adjoining cartons to provide channels
in the arrangement communicating with the apertured recessed zone
of the central body section of the cartons.
Description
BACKGROUND OF THE INVENTION
This invention relates to ventilated shipping cartons and more
particularly to ventilated shipping cartons for transporting
produce such as fruit, vegetables or the like which for any of a
variety of reasons must be cooled or maintained at a certain
temperature during transit.
It is known that many fruits and vegetables continue to respire and
generate heat at different rates even after they have been
harvested. This creates a problem when the produce must be shipped
over long distances during which this heat continues to build up in
the produce. The shipment of California produce to East Coast
markets is a prime example of this. Certain fruits such as, for
example, grapes, plums, cherries, apricots and nectarines are known
to give off appreciable amounts of heat during transit. It is
imperative that this heat be removed during transit and the produce
maintained at a given temperature or else the produce will rot and
spoil.
In normal practice, the produce is papckaged and then shipped in
refrigerated railway cars or trucks which remove this heat and
maintain the produce at a controlled temperature during shipment.
Cold air from the transit refrigeration unit must be able to
circulate easily through all of the produce load to remove the heat
and thereby reduce the produce temperature to, and maintain it at,
a desirable transit temperature. Poorly vented produce containers
or shipping arrangements can prevent effective refrigeration from
taking place.
In large loads of inadequately vented shipping containers, cold air
from the refrigeration unit is largely prevented from moving down
through a load of produce. Instead, much of the air moves around
the load or seeks other more direct routes in returning to the
refrigeration unit for further cooling. Air that by-passes the load
of produce is not warmed by heat from the load and returns to the
refrigeration thermostat with a false signal that the return air is
cold and that the product temperature has been lowered to near the
thermostat setting. Consequently, the thermostat then signals the
refrigeration unit to provide even less refrigeration and air
circulation to the load with subsequent adverse results.
In many cases, the produce is pre-cooled prior to loading it in
transit vehicles and is then simply maintained at its pre-cooled
temperature by the refrigeration unit of the vehicle. In other
cases, the produce is not pre-cooled and is either cooled to a
given temperature, or maintained at a given temperature, using the
refrigeration unit of the transit vehicle.
When large loads of produce involving perhaps hundreds of cartons
of fruit or vegetables are being transported, it is essential that
the stacking arrangment used provide adequate channels whereby the
refrigerated air can effectively permeate the stacking arrangement
and remove sufficient heat to cool substantially all of the produce
in the stack. Unless this occurs, hot spots can occur with
resulting spoiling of the produce. It is generally known,
therefore, that in loading produce cartons for transit, some
spacing arrangement must be provided between them to create
channels in the stacking arrangement through which the refrigerated
air can move. A variety of techniques have been used for this in
the past, none of which are entirely satisfactory.
At the present time, the wooden lug box is widely used for the
shipment of produce. This box is the common, slatted box with
elongated apertures between the wood slats often seen in retail
produce markets. To provide effective refrigeration of such boxes
during shipment, a common practice is to place vertical and
horizontal strips of wood between adjoining vertical and horizontal
layers of these boxes to space them apart and thus provide the
required channels for refrigerating the stacked boxes. These strips
are commonly called "gates" or "car strips." Such spacer strips and
other techniques used to space the cartons for shipment are
generally referred to as "dunnage." The installation of dunnage is
expensive and time-consuming. For example, the wood represents an
added cost, and a substantial amount of labor is required to
emplace the vertical and horizontal wooden strips. The boxes
themselves do not have sufficient dunnage to achieve the required
spacing. In addition to the dunnage problem associated with such
boxes, they are generally more expensive than boxes prepared from
other materials such as, for example, corrugated paperboard.
With the aforementioned disadvantages of the prior art in mind, it
is a general object of this invention to provide an inexpensive but
strong shipping carton which eliminates the dunnage requirements of
prior art cartons yet still provides adequate ventilation and
cooling for the produce during transit.
It is another object of this invention to provide a shipping carton
having self-contained dunnage of such type as to virtually assure
the maintenance of adequate channeling throughout a shipping
arrangement, regardless of carelessness in assembling the
arrangement or shocks to which the arrangement is subjected during
transit.
It is another object of this invention to provide a ventilated
shipping carton having self-contained dunnage as well as high
end-to-end, torque and stacking strength.
It is still another object of this invention to provide a shipping
carton having a smooth interior containing no sharp edges or rough
surfaces against which the produce can rub, thus eliminating the
need for packing materials such as liners, curtains or the like
normally used in conventional cartons.
It is a further object of this invention to provide a ventilated
shipping carton which is made from corrugated paperboard which has
adequate strength and ventilation characteristics as well as
self-contained dunnage which is also made from corrugated
paperboard.
It is a still further object of this invention to provide a
shipping carton in which carton bottom sag is reduced by providing
firmer support for each end of the load bearing panel of the
carton.
These and other objects of this invention will be apparent to one
skilled in the art from a consideration of this entire disclosure
including the accompanying drawings.
SUMMARY OF THE INVENTION
The above objectives are accomplished, in accordance with this
invention, by providing a shipping carton having a body section for
holding the carton contents which is at least partially open at
opposed ends thereof and means closing each of these open ends
which further include portions for spacing the carton from
adjoining cartons in a shipping arrangement containing a plurality
of such cartons. These spacing portions provide substantially
vertical and horizontal channels in the shipping arrangement which
are maintained throughout transit to provide access for the
refrigerated air to substantially every carton in the
arrangement.
More particularly, each open end of the body section is covered by
a closure panel which includes means for attaching the closure
panel to the body section. These attachment means engage the outer
surface of the body section adjacent the open end of the body
section and form thereon a zone of peripheral projections which
space the remainder of the carton, on all sides, from adjoining
cartons in a stacked arrangement of the cartons. In such an
arrangement, the peripheral projections of adjoining cartons will
normally be aligned. These projections in turn define on the outer
surface of the body section a peripheral zone or area which is
recessed with respect to these projections. This recessed zone is
apertured to provide communication between the interior and
exterior of the body section.
In a stacked arrangement of the cartons, the apertured portion of
the body section is suspended between the peripheral projections at
each end of the carton and is effectively spaced from any portion
of the adjoining carton by the contact of the peripheral
projections with those of adjoining cartons. The recessed zone of
the body section of each carton cooperates with the recessed zone
of the adjoining cartons to create intercommunicating vertical and
horizontal channels throughout the shipping arrangement, portions
of which surround the apertured portion of the body section and
communicate with the carton apertures. When refrigerated air is
passed through these channels, it is effectively distributed
throughout the entire shipping arrangement and through the interior
of each carton to insure effective ventilation and cooling of each
carton in the arrangement.
It has been found that in order to provide adequate distribution of
aperture area in the recessed zone of the carton to effectively
cool the entire carton contents and avoid isolated hot spots in the
carton interior, it is desirable for the area of the recessed zone
of the body section to occupy at least about 33 percent of the
surface area of the body section, including that disposed beneath
said projections. On the other hand, to facilitate proper carton
alignment and spacing in a shipping arrangement involving numerous
cartons, it has been found desirable for the area of the recessed
zone to not exceed about 75 percent of the surface area of the body
section, including that disposed beneath said projections. Stated
another way, it is desirable that the peripheral projections
provide sufficient flat area for the cartons to remain aligned when
the shipping arrrangement is subjected to impact or other shocks,
as well as to provide for easy assembly of the shipping arrangement
without the need for a fastidious alignment of the projections.
Another reason for generally not permitting the recessed area to
exceed 75 percent is that carton sag may result. The recessed area
is suspended between and supported by the peripheral projections.
Since the distance between these projections normally increases as
the recessed area increases, the length of the unsupported recessed
area will likewise increase, with greater probability of its
sagging under a heavy load.
Since only the recessed portion of the carton's body section is
normally accessible to the refrigerated air in a shipping
arrangement, the carton apertures are provided in this recessed
portion. It has generally been found that to provide minimal
adequate ventilation and cooling, the total area of the apertures
should occupy at least about 10 percent of the surface area of the
recessed area. On the other hand, an excessive aperture area could
cause the box to lose too much of its "end-to-end" strength thus
rendering it vulnerable to collapse on impact. Moreover, if the
carton was apertured on its bottom, excessive apertures could
create a sag problem by weakening the bottom panel. Thus, it has
been found that the area of ventilation apertures should not exceed
abouot 50 percent of the surface area of the recessed zone of the
body section.
It will be appreciated, of course, that the above mentioned
percentages of recessed area and aperture area are a function of
the carton proportions and accordingly will vary as these
proportions vary. The term "surface area" when used in conjunction
with the body section or recessed zone of the carton means the
inner surface area of the respective portion of the carton.
Certain embodiments of the carton of this invention were described
by F. G. Mitchel, et al. in an article entitled "Cooling Trials
With Plastic Tray Pack Nectarines In Various containers,"
California Agriculture, September 1971, pages 13-15. This article
discusses some of the problems encountered in ventilating and
refrigerating produce during shipment and details favorable
experimental results obtained with the cartons of this invention as
compared to various other types of shipping cartons.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the three blanks used to prepare a
preferred embodiment of the shipping carton of this invention.
FIG. 2 is a perspective view showing the blanks of FIG. 1 in a
partially assembled position, with the three components of the
carton not yet joined together to form a single carton.
FIG. 3 is a perspective view of the assembled carton of FIG. 2 with
its top open to facilitate the loading of the carton.
FIG. 4 is a perspective view of the assembled carton of FIG. 3; the
arrows show gas flow around the carton.
FIG. 5 is a sectional view taken generally along the line 5--5 of
FIG. 4.
FIG. 5A is a view identical to FIG. 5 except a portion thereof is
shown schematically in order to better illustrate the recessed zone
of the carton and the encircling channel for gas flow (arrows)
provided by said recessed zone.
FIG. 6 is a sectional view taken along the line 6--6 of FIG. 4.
FIG. 7 is a perspective view of a stacked shipping arrangement
employing a plurality of the cartons of FIG. 4.
FIG. 8 is a side elevational view of the shipping arrangement of
FIG. 7.
FIG. 9 is a sectional view taken generally along the line 9--9 of
FIG. 7, and is intended to illustrate schematically the flow
pattern of cool air (arrows) through the horizontal and vertical
flow channels created in the shipping arrangement of FIG. 7 by the
cooperating recessed zones of adjoining cartons.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Individual Carton
A preferred embodiment of the shipping carton of this invention is
depicted in FIGS. 1-6. The carton is conveniently prepared from
three blanks, as shown in FIG. 1. The central body section blank 10
comprises an unapertured bottom panel 11 and two apertured wall
panels 12 and 13, each of which is foldably attached to opposed
edges of bottom panel 11 by score lines 14 and 15, respectively.
Shortened top flaps 16 and 17 are foldably attached to wall panels
12 and 13, respectively, along respective score lines 18 and
19.
Wall panels 12 and 13 contain a plurality of vertically elongated
ventilation apertures 20 which are circular at each end thereof.
These apertures are generally disposed centrally between score
lines 14-18 and 15-19, respectively. The number and geometric
configuration of apertures 20 can vary depending upon the type and
degree of carton ventilation required.
As shown in FIG. 2, body section blank 10 is assembled by folding
panels 12 and 13 upward along score lines 14 and 15 to form a
rectilinear body section 22 whose opposed ends (shown generally at
23 and 24) are open because only two wall panels (12, 13) were
provided instead of the four wall panels normally encountered in
most cartons. Body section 22 can, of course, take on any
geometrical form which is required to accommodate the contents of
the carton, or for other reasons. Top flaps 16 and 17 are folded
outwardly, as shown in FIG. 2, to provide access to the interior of
body section 22 from the top of the carton.
Returning to FIG. 1, two identical end cap blanks 26 are provided
for closing the open ends 23, 24 of body section 22 to retain the
carton contents therein during transit. Each blank 26 comprises a
central closure panel 27 and four extension panels 28, 29, 30 and
31, each of which is foldably attached to an edge of panel 27 by
score lines 32, 33, 34 and 35, respectively. Each corner of panel
27 is provided with a relief cut-out 36 which allows extension
panels 28-31 to be folded substantially vertically away from panel
27, to form an end cap member 38 for open ends 23, 24 of body
section 22 (see FIG. 2). Cap members 38 can be joined to body
section 22 in any convenient manner such as by coating the inner
surface of panels 28, 30 and 31 with an adhesive (as represented by
the dotted area in FIG. 2) and then applying cap member 38
externally over the outer surface of body section 22 until the
edges of wall panels 12, 13 engage closure panel 27. It is thus
seen that open ends 23, 24 of body section 22 are closed by panel
27 of cap member 38 and that panel 27 is held in place by panels
28, 30 and 31 which form a U-shaped band around panels 11, 12 and
13 of body section 22.
FIG. 3 shows the carton with the two cap members 38 affixed to each
end of body section 22 with top flaps 16 and 17, as well as
extension panels 29 of cap member 38 folded outwardly to facilitate
the loading of produce or other contents into the carton. As soon
as the carton is loaded, flaps 16 and 17 are folded inwardly to
cover the carton contents and extension panels 29 are then folded
on top of flaps 16 and 17 and affixed thereto in any convenient
manner such as by the application of an adhesive to the inner
surface of panel 29 (as represented by the dotted area in FIG. 3).
The carton is thus sealed and ready for shipment. Because flaps 16
and 17 are shortened, there is provided a view space 39 for quickly
checking the condition of the contents. Of course, in certain
cases, flaps 16 and 17 could be eliminated or replaced by a single
top flap. In certain other cartons, the view space can be
eliminated by proper sizing of the top flap or flaps.
Referring to FIG. 4, it is seen that panels 28-31 of cap member 38
vertically extend from panel 27 so that cap member 38 forms a
rectilinear cup-like member which externally fits over each end of
body section 22. Panels 28-31 are affixed to the outer surface of
body section 22 and form a peripheral band which slides over the
outer surface of body section 22 at each open end to hold closure
panel 27 in place. The two peripheral bands at each end of the body
section, generally designated as 40 and 41, each form a peripheral
projection on the outer surface of body section 22 which extends
around the entire body section 22. These projections define on the
outer surface of the body section 22 a zone, generally identified
as 42, which also extends peripherally around the body section 22
but which is recessed with respect to peripheral bands 40 and 41.
It is seen that the apertures 20 are provided in this recessed zone
42. As shown in the drawings, apertures 20 are provided only on
opposed wall panels 12, 13. However, they could also be provided
either on bottom panel 11 and/or top flaps 16, 17 or they could be
provided on all of the panels which form the recessed zone.
Preferably, however, only the wall panels 12, 13 are apertured.
As already discussed, it is desirable that recessed zone 42 occupy
at least 33 percent but not more than 75 percent of the surface
area of body section 22. Preferably, recessed area 42 occupies from
about 40 to about 60 percent of the surface area of body section
22, and even more preferably from about 40 to 50 percent. It is
equally desirable that the apertures in recessed zone 42 not occupy
a total aperture area less than about 10 percent nor greater than
about 50 percent of the surface area of the recessed area 42.
Preferably, the apertured area occupies about 15 to 25 percent of
the surface area of the recessed area 42.
The preferred fabrication material for both cap members 38 and body
section 22 is corrugated paperboard, although other conventional
and known fabrication materials can also be used. Corrugated
paperboard is preferred because it has been found to provide the
requisite strength requirements for a produce shipping carton and
because it is relatively inexpensive and readily available. The
body section 22 is preferably fabricated from single-wall
corrugated paperboard typically having a thickness on the order of
about one-eighth inch. For the strongest carton, the flutes of body
section 22 should extend longitudinally between peripheral bands 40
and 41 as shown in FIG. 5. Cap members 38 are preferably fabricated
from double-wall corrugated paperboard having a thickness in the
range of about one-fourth inch. However, thicknesses in excess of
one-fourth inch can also be used for cap members 38, and generally
thicknesses in the range of between one-fourth inch and
seven-sixteenths of an inch or even higher are acceptable. Cap
member 38 is preferably fabricated so that the flutes of panels 28
and 30 extend from top to bottom in the carton, perpendicular to
the flutes of body section 22, to impart added stacking strength,
as shown in FIG. 2.
The carton of this invention has extremely good strength
characteristics and high torque resistance. Its stacking strength
and end-to-end strength, for example, have been generally found to
be quite satisfactory and generally comparable to previously used
shipping cartons. The high strength of the carton is believed
largely due to the fact that extension panels 28-31 are integral
with enclosure panel 27 so as to provide very stiff corners in cap
member 38. Extension panels 29 and 31 are disposed so their outer
edges are aligned with substantially the entire cross section of
adjoining extension panels 28 and 30. This provides added support
strength for panels 29 and 31 when the carton is placed in a
stacked shipping arrangement, and prevents panels 29 and 31 from
collapsing inwardly into the carton contents.
As best seen in FIG. 4, a recessed zone 42 is provided between
peripheral end bands 40 and 41. Since bands 40 and 41 extend about
the entire periphery of the carton, the body section is similarly
recessed about its entire periphery. The advantage of this, as will
be discussed more fully hereinbelow, is that intercommunicating
vertical and horizontal channels are provided in stacking
arrangements using the carton of this invention. These channels
distribute cool air to virtually every carton in the shipping
arrangement.
The carton of this invention can be modified in accordance with
various known techniques for improving the wet strength or other
characteristics of the carton. This becomes important when the
contents are to be shipped in a moistened condition. For example,
it has found especially advantageous to improve the wet strength of
the corrugated paperboard cartons of this invention in accordance
with procedures such as those described in commonly assigned U.S.
application Ser. No. 54,201, filed July 13, 1970, now issued as
U.S. Pat. No. 3,695,219.
The surfaces of the corrugated paperboard used to prepare the
carton of this invention can also be coated with any of a variety
of known materials or compositions for imparting wet strength to
the paperboard. For example, the surfaces can be coated with
various types of waterproofing waxes in accordance with known
techniques and procedures.
The Cartons In A Stacked Shipping Arrangement
The unique cooling and ventilation provided by the shipping carton
of this invention, when placed in a multi-carton stacked
arrangement for transit, is illustrated in FIGS. 7-9. The Figures
show three vertical columns and three horizontal columns of the
carton in a shipping arrangement wherein the spacing peripheral
bands 40, 41 of each carton in the arrangement are in alignment
with the spacing peripheral bands 40, 41 of adjoining cartons in
the shipping arrangement. This alignment of spacing bands 40, 41
provides a plurality of interconnected vertical and horizontal
channels formed from the cooperating recessed zones of adjoining
cartons, as best seen in FIG. 9, which effectively circulate the
cool air throughout the entire shipping arrangement.
Referring in particular to FIG. 9, it is seen that cool air enters
the shipping arrangement from the top and proceeds downwardly
through the arrangement by means of vertical channels 50 and 51
which extend substantially throughout the entire shipping
arrangement from top to bottom. Communicating with vertical
channels 50, 51 are the wall apertures 20 of each individual carton
in the arrangement and horizontal channels 52, 53 and 54 which also
extend laterally throughout substantially the entire shipping
arrangement. As the cool air enters channels 50, 51 from the top of
the arrangement it passes downwardly into the shipping arrangement
through the channels and then is diverted laterally, as indicated
by the arrows in FIG. 9, either through apertures 20 of adjoining
cartons or through horizontal channels 52-54. As the cool air
passes through apertures 20 into the interior of the cartons, it
contacts the contents and removes unwanted heat to maintain the
produce at a desired cool temperature. Thus the contents of the
cartons are cooled by air which enters and leaves through apertures
20 while the exteriors of the cartons are bathed in a stream of
cool air which is flowing through vertical channels 50, 51 and
horizontal channels 52-54. Even though the bottom most horizontal
layer of the shipping arrangement rests on the floor, the
peripheral bands 40, 41 of these cartons provide a horizontal
channel 54 under the body section of the cartons which insures a
flow of cool air across the bottom of these cartons.
It is thus seen that the cool air cools both the inside and outside
of virtually every carton in the shipping arrangement. There are,
therefore, no isolated hot spots or pockets in the shipping
arrangement which are not adequately cooled and which could
otherwise cause rotting or spoiling of the produce.
After the cool air has effectively passed through the shipping
arrangement by means of vertical channels 50, 51 and horizontal
channels 52-54, the heat associated with the produce has been
removed with a consequent increase in the temperature of the cool
air. The spent air is then returned to the refrigeration unit and
thermostat at a higher temperature which is truly indicative of any
need for further cooling in the shipping arrangement. Thus, the
thermostat functions properly to insure cooling the recycled air to
just the right temperature for effective cooling.
It can be seen from FIGS. 7-9 that peripheral bands 40, 41 of each
carton serve several purposes. First, they join end closure panel
27 to body section 22 to close off the opposed open ends 23, 24 of
central body section 22. Secondly, by creating peripheral
projecting bands 40, 41 on the surface of body section 22, they
provide carton spacing means or dunnage which forms an inherent
part of the carton and thus eliminate the time and effort normally
required to install vertical and horizontal wooden strips between
adjoining columns of cartons in a conventional shipping
arrangement.
The dimensions of extension panels 28-31 also provide a relatively
large area of contact between adjoining peripheral bands 40, 41.
For example, for the embodiment shown in the drawings, the panels
28-31 extend inwardly from panel 27 about 4-4 1/2 inches. This is
an advantage for several reasons. First, it makes initial stacking
of the cartons easier because precise alignment of the peripheral
bands is not required to insure the carton spacing which creates
channels 50-54 throughout the shipping arrangement. It can be
appreciated that if bands 40, 41 were very thin, initial
preparation of the stack could be quite time consuming in order to
obtain proper alignment of the bands. Secondly, the broadened area
of surface contact allows for more slippage of the cartons in the
arrangement with respect to each other, upon subjection to impact
or other disorienting forces, without bands 40, 41 becoming
disengaged to the extent that channels 50-54 become blocked. If
these bands were very thin, it can be seen that it would not take
much impact to cause adjoining bands 40, 41 to disengage and block
channels 50-54. Thirdly, bottom panel 11 is considerably
strengthened by reducing its unsupported central span by moving its
two end support points closer together. This reduces undesirable
sag of panel 11 under the weight of the carton contents.
An important advantage of the carton is that strengthened bands 40,
41 in conjunction with the ends of wall panels 12, 13 bear the
weight of cartons above them in the stacking arrangement thus
insuring that the suspended portion of central body section 22 is
spared this weight bearing function.
As can now be appreciated, the shipping carton of this invention is
equipped with self-contained dunnage and can be quickly and
conveniently stacked into a shipping arrangement without the use of
conventional dunnage. Moreover, there is the assurance that
adequate channels for circulation of cool air through the
arrangement will be maintained even if the arrangement is subjected
to impacts during transit which cause some movement of the cartons.
The carton of this invention is further enhanced by the fact that
it can be fabricated from relatively inexpensive corrugated
paperboard but yet has strength characteristics comparable to
commonly used commercial cartons.
The specific and detailed information given above is intended as
illustrative only and such modifications and alterations thereof as
would be apparent to one skilled in the art are deemed to fall
within the scope and spirit of the claims appended hereto.
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