Note: Descriptions are shown in the official language in which they were submitted.
o
BACKGROUND OF THE INVENTION
Field oL' the Invention
The present invention relates to collapsible containers
having pallet-type bases with ~pright container walls pivoted to
the base and adapted to be moved to a folded position on the
pallet for return transport in the empty condition. This type
of contalner is aesigned for fork lift handling and is adaptable
~or a wide variety of general utility p~rposes ranging from the
transport or storage of packaged goods to bulk commodities such
as produce and the like.
Tl~e Prlor Art
Collapsible containers having foldable side walls for return
shipping are well known in the prior art and are subject to a
wiae range of uses. Such containers range in size from rather
large capacity cargo container units for rail and shipboard
han~ling to rather small light-weight containers designed for
s~ch com,~odities as bakery goods and farm produce. Examples of
the latter type of collapsible containers made from molded flex-
ible plastic with integral hinge str~ct~res and snap fitting
joints are contained in the Saunders et al U.S. Patents Nosn
3870185 and 3874546 and the Waller U.S. Patent No. 4320845.
These containers may be characterized as being rather light
weight small capacity str~ctures ana are designed for carrying
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light weight fragile o~ frangible articles such as loaves of
bread or egg cartons.
Larger bin structures for general utility use, of the
type capable of being handled by a fork lift, have also been
constructed from molded rigid plastic materials. This type of
container may be characterized as a pallet base container. The
Kardell U.S. Patent No. 4057165 is one such device wherein
1exible plastic hinge members permit the side walls to be
folded onto the pallet base. The Vande Drink U.S. Pa~ent No.
4235345 and the Te-Chi Hsu U.S. Patent No. 4300695 are further
examples of injection molded collapsible containers usable for
general utility purposes. The Te-Chi Hsu patent is exemplary of
injection molded plastic structures utilizing metal hinge pins
to accomplish the hinging function between plastic panels. The
metal hinge pins are designed to withstand lateral loads and are
intended to provide the necessary strength to the structure.
Generally speaking, the problem encountered with
prior art efforts to design molded plastic containers for heavy
duty purposes has been the difficulty in providing a pallet type
base with foldable walls which, when erected, are strong enough
to carry extremely heavy loads such as machine parts or heavy
metal objects for instance. Although it is well known in the
art that hinge members may be molded integrally with the side
and bottom walls and simply snapped together to form collapsible
containers, the resulting structure will not stand up under
heavy use.
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~n the other hand, if such devices as metal clips, metal hinge
pins or other reinforcing members are added to the collapsible
multi-paneled plastic structure the parts usually become
separated and lost when the container is collapsed ~or return
shipment. In addition, such designs involving multiple separaté
parts of diverse materials are extremely expensive to manufac-
ture and usually too cumbersome to be practical. other consid-
erations such as replacement of worn out parts and ~he ability
to keep the container structure clean have plagued the industry
for years.
S~JMARY OF THE INVENTION
The present invention provides a heavy duty, high strenyth,
collapsible pallet type container which may be formed entirely
by injection molded plastic techniques and which is designed for
nesting when stacked either in the erected or collapsed mode.
The side and end walls of the container are pivotall~ connected
to the pallet base by means of integrally molded snap-fitting
hinaes. There are no special clips or other metal parts and
hence no lose or separate parts used in conjunction with the
container at all. The special structural configuration of the
mating side and end walls and the pallet base insure that no
lateral loads are placed on the molded hinge structures, hence
extremely high-level loading interior of the container is
possible. The novel configura'i~n of side wall and end wall
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~terlocking results in enhancing the engagement between the end
and side walls with increas2d loading within the container.
Longitu~inal movement in the vertical direction between the end
and side walls or side wall shifting is also prevented by the
novel connection and interaction bet~een the end and side wall
edges. Likewise, special provision is made for absorbing lat-
eral shock forces directed against the outside surface of the
erected side walls, thereby protecting the molded hinge elements
connecting~the end and side walls to the pallet base. The ri-
gidity of the connection or engayement between the end and side
walls is extremely important during lifting of a filled con-
tainer by such means as a fork lift. There is a normal tendency
to skew the ends and side walls during lifting, resulting in
hinge damage. This skewing is prevented by means of the novel
structure which interconnects end and side wall edges~
Provision is also made for a slightly domed or upwardly
convexed pallet surface which forms the bottom wall of the
~onta;ner. Loads received by the convex bottom wall are trans-
erred into the side and end walls in such a manner as to still
~urther enhance their engagement. Two folding patterns for
collapsing the side and end walls onto the pallet base are dis-
closed, and in all instances nesting type stacking is possible
without endangering the hinged joints between the side and end
walls and the bottom wall by the added weight of stacking.
Additionally, the container is so designed as to receive a lid
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stroc.ure of appropriate configuration ~/ith n~n~ of the lateral
forces of the loaded side and end walls being transferred to the
lid. Because of the novel configuration of the integrally
molded hinge elements and the interfacing bet~1een ~he side walls
~nd end walls with the base walls of the pallet, it is possible
to construct a container with extremely smooth interior
s~lrf~ces. This feature is of importance with the handling o
~r;cultural produce and the like and may be important in those
instances where~ cleaning of the intelior of the c~ntainer is
de~irable or necessary. All of these advantages are obtained
with the present invention while keeping the manufacturing costs
of the container at a competitive level. Advantages are also
obt~ined in return shipping, wherein the container is reduced in
si~e in the range of 2.8 to 1, to 3 to 1. This return ratio is
conâidered to be of extreme importance taking into consiaeration
present day shipping rates.
BRIEF DESCRIPTION OF THE DRAWI~GS
Reference is made to the accompanying drawings illustrating
preerred embodiments of the invention wherein;
Fig. 1 is a perspective view of a first embodiment of
the collapsible container of the present invention in its fully
assembled or erected condition;
- Fig. 2 is a perspective view of the embodiment of Fig.
1 illustrating the order of folding the side and end ~alls to
obtain the collapsed confiauration of the container for return
shipment;
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Fig. 3 is a partially sectioned isometric detail of
the area indicated by the broken line circle in Fig. 2;
Fig. 4 is a transverse sectional view showing the
folded position of the end and side walls o the pallet
container;
Fig. 5 is a transverse cross-section taken above
lines 5-5 of Fig. 4;
Fig. 6 is a partial elevation of the outside wall of
the container in its erected condition showing the placement of
snap hinge elements acting between the side and end walls of the
container and the pallet base wall;
Fig. 7 is a cross-sectional view along lines 7-7 of
Fig. 6 illustrating a hinge protector structure for absorbing
inwardly directed shock loads against the erected side walls of
the container;
Fig. 8 is an exploded partially sectioned detail of
one form of snap hinge indicated by the dotted line circle 8 in
Fig. 6;
Fig. 9 is an exploded partially sectioned detail of a
second form of snap hinge indicated by the dotted line circle 9
in Fig. 6;
Fig. 10 is an elevational detail illustrating a wall
latch structure acting between the end and side walls to prevent
inward folding of the erected walls prior to filling of the bin;
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Fig. 10A is a perspective view of the sliding latch
= --element shown in Fig. 10;
Fig. 11 is a center line sectional view showing the
folded position of the end and side walls of a second embodiment
of the collapsible bin; and
, Fig. 12 is a cross-sectional view taken along lines
¦ 12-1~ of ~ig. 11 showing the position of the folded end and side
walls.
~ ., DESC~<IPTION OF THE PREFERRED E~;BODI~lENTS
Fig. 1 illustrates a collapsible container 10 according to
the present invention ~7hich includes the side walls 11, opposed
end walls 12 and a pallet base or bottom wall structure 13. The
entire structure of the container is most advantageously formed
from a material such as high density polyethylene utilizing well
¦ known injection molding processes. The thickness of the side
wall, end wall and bottom wall structures may vary and will be
determined by the strength and durability reo~irements for any
particular bin or container. It will also Le noted that any
configuration of ribbing or reinforcing may be provided for the
~all members as is well ~nown in prior art. Preferably, how-
ever, the inside surfaces of the side walls 11, end walls 12,
and the bottom pallet wall 13 are smooth and free of obstruc-
tions so as to be easily cleaned. One o. the end walls 12, as
shown in Fig. 1, may also be provided with a hin~ed door or gate
14 to facilitate unloading of the container under certain condi-
tions if desired.
Referring to Figs. 3-5, the pallet base 13 includes
the bottom wall 16 molded with appropriate strengthening webs
16a integral therewith. The bottom wall 16 is formed in an
upwardly convexed curve as seen most clearly in Figs. 4 and 5
and extends into the base side and end walls (also referred to
as subwalls) 17 and 18, respectively, to which the side wall and
end walls 11 and 12 respectively are pivotally attached. As
shown most clearly in Fig. 3, the base side walls 17 extend to a
higher elevation then the base and walls 18 to permit folding as
will presently be described in detail. As is customary, the
pallet base 13 is formed with a support wall around the bottom
periphery thereof and includes the spaced apart openings 19, two
per side, which adapt the pallet for lifting by the tines of a
fork lift. With this arrangement, the pallet may be picked up
from any side by a fork lift for transport.
Each of the base side wall members 17 is provided
with a groove 21 extending the length of the inner edge of the
wall which provides a shoulder 22. The shoulder acts as a load
bearing surface in cooperation with a lip formed on the
associated side wall as will presently be described. Likewise
each base end wall 18 includes a groove 23 which provides a
shoulder 24 for cooperation with a lip on the associated end
wall or the same purpose.
The side walls 11 are pivoted to the base side walls
17 along the common pivotal axis of the multiple sets of hinge
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structures 26 and ~7. The details of these hinge structures
will be described in detail later with relation to Fig. 8 and 9
of the drawings. It will be understood that multiple sets of
these hinge structures 26 and 27 are used along the lower edges
of both the side walls 11 and the end walls 12. These sets of
hinge structures are identical in detail and the number and
placement of the hinges will depend on the design of the
particular container. Each side wall 11 is provided with
identically formed vertically extended flange members 28 formed
on the edge of its inner surface. As illustrated in Figs. 2 and
3, each flange 28 on the opposite ends of each of the side walls
has a groove 29 of some depth with connecting webs 31 vertically
spaced along its length. The inner face of the flange 28 is
provided with a plurality of notches 32 also vertically spaced
along its length. The webs 31 and notches 32 are designed to
cooperate with the mating webs and notches in the end walls when
the walls are in the erected position as will presently be
described. The bottom inner edge of each side wall 11 comprises
a lip member 33 running the length of the wall. The lip 33 is
designed to cooperate and interfit with the groove 21 and
shoulder 22 of the adjacent base side wall to provide a bearing
surface for absorbing the forces acting against the inner
surface of the walls when the container is loaded. ~s seen most
clearly in Fig. 3, the lip 33 engages the groove 22 in the base
side wall and the bottom surface of the side wall 11 rests
vertically on the top edge of the wall 17 when the side wall is
erected~
The end walls 1~ may be identical in detail and are
connected to the base end walls 18 by means of hinge member
which
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are identical to those used for the side walls 11. Also a lip
38 is formed on the bottom edge of each wall 12 and cooperates
with the groove ~3 and shoulder 2~ in the manner described with
relation to the lip 33 of the side walls 11. As seen in Fig. 3,
the vertical side edge of each end wall includes a vertically
extending flange 34 which is designed to engage the groove 29 in
the adjacent side wall flange when both end and side walls are
erected. The flange 34 is provided with a plurality of spaced
notches 36 which are vertically spaced so as to receive the webs
31 in the side wall flanges 28. Likewise, the flange 34 is
provided with a plurality of spaced webs, such as the web 37,
which engage the notches 32 in the side wall flange 28. This
structural arrangement prevents the end walls from pivoting or
being forced passed the vertical when they are raised against
the 1anges 28 of the erected side walls. Any force applied to
the inside wall surfaces will, of course, enhance the engagement
batween the wall edges. The engagement between the respective
notches and webs on the flanges of the end and side walls serves
to lock the two walls together against any relative vertical
shifting. This shifting or skewing of the side and end walls
normally tends to occur during lifting of the loaded container
with a fork lift and may result in severe hinge damage.
Referring now to Figs. 6 through 9, the hinge
structures will be described in detail. The hinge member 26 as
well as the hinge 27 are molded integrally with the side and end
wall
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panels obviating the need for any special hardware or removable
~-~parts. The hinge structure 26 shown in detail in Fig. ~ in-
cludes a rec~angular hinge body 39 extendins from the bottom
edge of the associated side wall with the inner face thereof
being flush with the inside surface of the associated wall.
Although the detailed configuration of the hinge body may very
somewhat, each of the side walls of the hinge body is provided
with an elongated slot 40 which engages a boss or cylindrical
protrusion 41 formed on the side walls of a U-shaped opening 42
in the associated'base side or end wall. It will be noted that
slots 40 are open ended on the inward side thereof to permit'
insertion into the U-shaped opening into ensaaement with the
bosses 41 in a lateral direction. The hinge body 39 preferably
closely conforms to the configuration of the opening 42 so as to
substantially close the opening when the side wall is in place.
The body 39 also includes a downwardly e~tending protrusion 43
~hich engages a-shoulder 44 in the bottom of the U-shaped open-
ing 42. The hinge member 26 thus provides a pivot or hinge
point about the axis of the bosses 41 when the side,wall is
folded inwardly. The protrusion 43 and the shoulder 44 prevent
the side wall from being pivoted outwardly beyond the vertical
and also provide protection for the hinge in the event of any
lateral impact on the outside wall of the container.
Fig-. 9 illustrates the second type or hinge 27 utilized in
conjunction with the hinge member 26. The hinge member 27 is
s~lbstantially more complex in its str~cture and is characterized
as a "snap hinge", having the added function of retaining the
end and sidf2 walls against removal from the pallet base. As
shown in Fig. 9, the hinge structure 27 is also molded inte-
grally with the side or end wall structure with its inside sur-
face ~lush with the inside face of the wall. The hinge has a
two part body comprising the body members 46 and 47. The body
member 46 is similar to one side of the body 39 of the hinge
mem~er 2S in that it contains an open ended slot 48 which is
designed to receive one of the hinge bosses 49 located in the U-
shaped opening 51 in the adjacent base wall. The pivotal axis
provioed by the bosses 49, of course, coincides with the axis of
the bosses 41 of the adjacent hinge structure 26. The hinge
body 46 functions in the manner described for the hinge body 39
to provide a hinge point and also includes a protrusion (not
shown) for en~agement with a shoulder 52 in the opening 51 of
the adjacent base wall. This engagement prevents the side wall
or end wall ~rom being pivoted beyond the vertical position and
also provides impact protection for the associated hinge boss
49. The other body portion 47 has a relatively thin walled
shank 53 terminating in a cylindrical hub 5~ which is provided
with a bore 56 for receiviny one of the bosses 49. The body
portion 47 also includes a protrusion 57 for cooperating with
the snoulder 52 to limit the pivotal movement of the container
wall to the veLtical positlon. Since the shank 53 of the hinge
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body is somewhat flexible, it may be deformed ~o such an extent
as to allow the boss 49 to engage the bore 56 of the hinge
member and to snap the remaining part of the hinge into
engagement with the oppositely ~acing boss 49. With the snap
hinge 27 in engagement with the bosses 49, the associated
container wall is held in removable attachment with the pallet
base.
To further protect the pivotally attached side walls
from shock loads directed laterally against the outside surfaces
thereof, each hinge set 26-27 may be provided with an adjacent
wall protector structure 58 shown in detail in Figs. 3 and 7.
The purpose of the wall protector 58 is, of course r to prevent
any such lateral shock loads from damaging the hinge members 26
a~d 27. Referring to Fig. 7, the base side or end wall has a
recess formed therein which provides an upwardly and outwardly
directed stop or abutment 59 which engages an integrally formed
stop 61 on the associated side or end wall. The stop portion 61
is formed with a groove or slot 62 which receives and acts
against the terminal end of the abutment 59 on the base wall.
Thus, the protrusions ~3 and 57 on the hinge members 26 and ~7
respectively and the abutment 59 and stop member 61, prevent any
lateral shock loads, directed against the outside surfaces of
the walls, from being applied to the hinge structures. The
protective lips 33 and 38 on the side and end walls 11 and 12
respectively cooperate with the associated shoulders on the base
side and end walls to absorb lateral loading on the inside
surface of the walls to protect the hinges. The engagement
between
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the interlocking flanges on the mating edges of the ends and
side walls serve to absorb the remaining lateral loads applied
to the inner faces oE the walls as the container is illed thus
preventing any loading whatsoever on the hinge members.
In order to hold the end walls in their erected
position as shown in Fig. 1 prior to filling the container, each
end wall may be provided with slide latch structures 63 mounted
on each side edge adjacent the upper ends thereof for engagement
with the flanges 28 of the side walls 11. The slide latches may
be received in suitable openings 64 in the flanges 28 to hold
the end walls from collapsing inwardly until the container is
filled. Figs. 10 and lOA illustrate the details of a slide
latch structure which may be used for this purpose. As seen in
Figs. 10 and lOA, the slider 66 is held in position against the
end wall by means of the guides 67 which engage the tabs 68 on
the slider and allow the slider to be moved into engagement with
the slot 64 in the side wall flange 28. The slider 66 is held
against removal in the unlatched position by means of the latch
fingers 69 which engage appropriate depressions in the end wall
surface.
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As aforementioned, one or both of the end w211s 12
may be provided with a suitable door 14 which is connected to
the end wall by means of snap hinge connectors 74 which may be
identical to the snap hinge 27 shown in Fig. 9. It will be
understood, of course, that the bottom edge of the hinged door
will also ba provided with a lip (not shown) for engagement with
an appropriate shoulder on the wall 12 to absorb any lateral
loads on the door so as to protect the hinge members in a manner
previously described. Also the door 14 may be latched to the
end wall structure by means of slide latches 76 mounted on the
end walls. These latches may be substantially identical in the
structure and operation to the slide latch shown in Figs. 10 and
lOA.
Although no top structure is illustrated, it will be
obvious to those skilled in the art that a top structure may be
provided for the container with the proper configuration for
engaging the top edges of the erected ends and side walls.
Since the lateral loads on the ends and side walls are absorbed
by their novel interconnections, there will be no loads applied
to the cover structure.
Figs. 2, 4 and S illustrate the manner in which the
side and end walls are folded in order to obtain the stackable
collapsed container. Referring to Fig. 2, and assuming an empty
container, the slide latches 63 are first moved to the retracted
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position releasing the en~ walls 12 from the si~e walls 11. The
end wa~ls are then folded inwardly to rest on the base structure
or bottom wall 16 of the pallet as illustrated in Fig. 4. Since
the end walls 12 have a height which is greater then half the
distance across the bottom wall 16, the walls will overlap as
shown in ~ig. 4. The order in which the end walls are folded
is, of course, irrelevant because they are both pivoted at the
same height. The next step is to fold each of the side walls 11
inwardly ~iith the inwardly facing surfaces of the flanges 28 on
each end of each side wall coming to rest on the upper edges of
the base end walls 18. With this configuration, no weight or
stress is applied to the overlapped previo~sly folded end walls
1~. Also, since the base side walls 17 are higher in elevation,
the vertical height of the side walls 11 may be designed to be
one half of the length of the bottom wall 16 and pallet base as
shown in ~ig. 50 There is therefore no overlapping of the side
walls which form a stable platform on which to stack another
collapsed or fully erected container. Referring to Figs. 4 and
5, it is to be noted that the base end and side walls 17 and 18
are provided with a plurality of notches or openings 77 and 78
respectfully which are aligned with the reinforcing webs of the
outside surfaces of the side walls 11 to permit nesting. Ad-
ditionally, the peripheral edges of the end and side base walls
are inset as at 79 and 81 so as to permit the pallet base to be
nested onto the folded side walls of another container. The
recessing 79 and 81 also permits a folded or erected container
to be nested on top of another erected container~
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Figs. 11 and 12 illustrate a second embodiment of the
---invention wherein the side and end walls are hinged to the re-
spective base walls at four different elevations providing for a
container of smaller dimensions while preserving the ability to
stack the collapsed container with other collapsea or erected
containers. It will be understood that the hinge structures and
hinqe protective ~eatures o~ the Figs~ 1 - 10 embodiment will be
utili~ed in the construction of the container of Figs. 11 and
' 1~, the only di ference being the manner in which the side and
i end walls are folded inwardly to collapse the container. As
seen in Figs. 11 and 12, the pallet base 113 is provided with a
first base end wall 114 and a second base end wall 116. The end
wall 117 is pivoted to the base wall 116 at the pivot point 118
and the end wall 119 is pivoted to the base end wall 11~ at the
pivot axis 121. The pivot point 118 is located the approximate
thickness of the end walls and webbing above the pivot point
1 121. With this arrangement, the end wall 119 may be moved to
i the position shown in Fig. 11 lying substanti~lly flat on top of
the bottom wall of the pallet. The end wall 117 is then pivoted
inwardly so as to rest on top of the end wall 119.
Referring to Fig. 12, the base side walls 122 and 123
provide pivotal attachments for the side walls 124 and 126
. respectively. The pivotal attachment 127 for the side wall 126
¦ is located the thickness of a side wall and webbing above the
pivot point 12~ for the side wall 124, permitting the wall 126
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to lie flat on top o~ the side wall 124 and to be supported
thereby. As shown in Fig. 11, one flange 129 of the side wall
124 engages the top surface of the base end wall 11~ for support
along its length and the flanges 131 and 132 of the side wall
126 rest on the outside surface of the side wall 124. In order
to stack successive erected or collapsed containers on a
collapsed container, the base side walls 122 and 123 have corner
posts 133 and 134, respectively, formed by the side wall ends
so as to support the stacked containers without applying any
pressure to the folded side walls 124 and 126. For this
purpose, the peripheral edge of the pallet base is recessed as
at 136 so as to nest between the corner posts 133 and 134.
~ lthough the present invention has been described and
illustrated with respect to two specific embodiments thereof, it
will be apparent to those skilled in the art that modifications
to the structures described may be made without departing from
the spirit of the invention or from the scope of the appended
claims. What is claimed is:
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