U.S. patent number 3,840,115 [Application Number 05/260,116] was granted by the patent office on 1974-10-08 for stackable transport and storage container.
This patent grant is currently assigned to Krauss-Maffei A.G.. Invention is credited to Wilhelm Ladewig.
United States Patent |
3,840,115 |
Ladewig |
October 8, 1974 |
STACKABLE TRANSPORT AND STORAGE CONTAINER
Abstract
A stackable transport and storage container molded integrally
and unitarily from a synthetic resin, has a plurality of sidewalls
defining corners between them. Each of the sidewalls is formed
unitarily with a hinged strip which may be deflected inwardly and
held in place therein by a snap-arrangement to support a similar
container stacked thereon. When the strips are deflected outwardly,
they allow the slightly tapered walls of the vessels to be
interfitted or nested.
Inventors: |
Ladewig; Wilhelm (Munich,
DT) |
Assignee: |
Krauss-Maffei A.G. (Munich,
DT)
|
Family
ID: |
5810234 |
Appl.
No.: |
05/260,116 |
Filed: |
June 6, 1972 |
Foreign Application Priority Data
Current U.S.
Class: |
206/506 |
Current CPC
Class: |
B65D
21/068 (20130101) |
Current International
Class: |
B65D
21/06 (20060101); B65d 021/06 () |
Field of
Search: |
;220/97R,97E
;229/31R,DIG.11 ;206/506 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Lowrance; George E.
Attorney, Agent or Firm: Ross; Karl F. Dubno; Herbert
Claims
I claim:
1. A transport and storage container for nestling with like
containers and for the stacking of like containers thereon, the
container comprising a bottom and a plurality of walls in slight
tapered fixed relationship fixedly connected to said bottom, a
plurality of pedestals hinged to at least some of said walls and
deflectable from a position in which each pedestal lies outside the
horizontal outline of the container into a position wherein the
pedestal projects into the outline to support a similar container
stacked thereon, said walls, said bottom and said pedestals being
unitarily formed from synthetic resin and said pedestals being
provided at least at two diagonally opposite corners of the
container, said container having a rectangular plan configuration,
said pedestals each comprising at least one strip unitarily hinged
to a respective wall by a thin vertical web of the synthetic resin
and deflectable from a position in which the strip is generally
coplanar and flush with its respective wall into a position wherein
said strip extends generally transversely to its respective wall,
said strips extending vertically, said walls having recesses
accommodating said strips in the first-mentioned position, and
means for releasably retaining each strip in its last-mentioned
position.
2. The container defined in claim 1 wherein said means for
retaining said strip in its last-mentioned position comprises a
stud crossed by the respective strip upon its displacement from one
of its positions to the other of its positions with relative
deflection of the strip and stud whereby said stud thereafter
intercepts said strip.
3. The container defined in claim 2 wherein said studs are provided
on said bottom for engagement with the strips of a container
stacked therebelow.
4. The container defined in claim 2 wherein said studs are provided
on the bottom of the container carrying the strip engaged by said
studs.
5. The container defined in claim 1, further comprising means for
retaining each of said strips yieldably in the first-mentioned of
its positions.
6. The container defined in claim 5 wherein the last-mentioned
means includes studs engageable with said strips.
7. The container defined in claim 5 wherein each of said strips is
hingedly connected to a further strip hinged to another wall at the
respective corner, the strips at each corner being deflectable past
dead-center for displacement between their positions.
8. The container defined in claim 7 wherein four such strips
interconnected by three hinges and connected to said walls by a
further pair of hinges is provided at each corner of the
container.
9. The container defined in claim 1, wherein said strips extend
substantially into contact with the bottom of the container for
force transmission between the bottom of a container stacked
thereon and the bottom of a container provided with the strip.
10. The container defined in claim 1 wherein said strips are of
triangular configuration and have outer edges extending downwardly
at acute angles to the respective hinge axis.
11. The container defined in claim 1 wherein each of said strips is
shiftable between its positions with snap-action.
12. The container defined in claim 1, further comprising an
outwardly turned rim extending all around said walls and formed
unitarily therewith, a respective pedestal being provided at each
of the corners of the container and supporting a container stacked
thereon over a compression-free space, said walls being provided
with reinforcing ribs at spaced locations therealong.
Description
SPECIFICATION 1. Field of the Invention
My present invention relates to storage and transport containers
and, more particularly, to stackable box-like containers which are
generally upwardly open and of rectangular plan configuration.
2. Background of the Invention
Stackable box-like containers or receptacles are in widespread us
for many purposes and can be considered in two basic categories.
One basic-type of container may be delivered to the user in a
broken-down configuration and erected at the use site while the
other remains generally intact from the point of manufacture to the
point of use. While containers of the first type are easy to store
and to transport until used, they are disadvantageous because of
the efforts needed to erect the containers and place them in a
structural staple form to receive the goods to be contained
therein.
With containers of the second type, problems of stacking and
transport are encountered, although erection costs are minimal. In
recent years, with the ability of the synthetic-resin industry to
turn out inexpensive large objects, thermoplastic injection-molded
articles in the shape of upwardly open box-like containers have
been produced for many purposes. These containers may be of the
discardable or disposable type or reusable and may be employed in
the home, in industry and in agriculture.
The present invention is intended to deal with versatile stackable
receptacles for such purposes. For the harvesting of orchard crops
(fruits) and tender vegetables, the bushel basket has largely been
replaced by rectangular upwardly open receptacles injection-molded
or otherwise formed from synthetic resin. Such containers are also
used for the transport of fish and other comestibles, may be
employed in industrial plants for the movement of screw-machine
products and other small objects, and may be used between a source
of goods and the ultimate consumer, between a source of goods and a
marketing site, between departments of a goods producer etc. Since
large numbers of such containers may be required, they commonly are
provided with a slight upward divergent or downward taper so that
the outline of the base of each container lies within the outline
of the top thereof, the walls sloping inwardly from the top to the
bottom. This allows the containers to be nested before use.
However, it is frequently required that the containers be stacked
in a partially or completely filled state in such manner as to hold
the load of any superposed container off the goods in any lower
container. This is particularly important where the goods are
sensitive to compression or bruising as is the case with fruits and
vegetables.
There have been proposed systems in which the walls of such
containers are hinged to allow the container to be flattened for
transport and storage and to be erected subsequently whereby the
base of the container registers with the top of the next lower
container so that force transmission or load transmission takes
place through the container walls. This system has the
disadvantages of earlier arrangements requiring complex erection
procedures and has generally proved too expensive for the purposes
described. In another arrangement, the walls, bottom and rim of the
container are formed unitarily from a synthetic resin and the
container is asymmetrical so that in one position of the container,
it may be nested with an underlying and/or overlying container
while, in a position in which the container is swung through
180.degree., shoulders of the upper or lower container rest upon
ledges of the other. The latter system has the disadvantage that it
is not always possible to swing the container around through
180.degree. before stacking and that manipulation of the containers
is difficult. Moreover, these containers have not proved to be
capable of economically withstanding high loads.
OBJECTS OF THE INVENTION
It is the principal object of the present invention to provide an
improved container for the purposes described which will avoid the
aforementioned drawbacks.
A more specific object of the invention is the provision of an
improved container for the storage, transport and handling of
compression-sensitive goods which allows stacking of the containers
with force transmission from one container to the other and free
from compression of the container contents.
Another object of the invention is to provide a low-cost, easily
manipulated nestable container which may be stacked without
difficulty.
Another object of the invention is to provide a container structure
which allows nesting of large numbers of containers as well as the
stacking of the containers in force-transmitting relationship
whereby the nested contains occupy little space and can be brought
into stacked relationship without major reorientation of the
container.
SUMMARY OF THE INVENTION
These objects and others which will become apparent hereinafter are
attained, in accordance with the present invention, with an
upwardly open slightly taperd container, preferably having a
rectangular plan configuration and composes of a thermoplastic
synthetic resin such as polystyrene, polypropylene or polyethylene,
which is formed at at least two and preferably three spaced-apart
locations around the container with inwardly deflectable strips
hinged to the walls of the container about generally upright axes
and which normallly are generally coplanar with the wall for
nesting of the containers but can be deflected inwardly into the
path of the bottom of a similar container to be stacked thereon.
Thes strips, which form support members or pedestals for the
containers stacked thereon, preferably can be retained in their
inwardly deflected positions by a snap-action arrangement either in
the form of a detent or by providing the strip as part of a toggle
or like arrangement movable past a dead-center position. The strip
may thus have two operative positions on either side of the
dead-center position or on either side of the detent, the first
being an outer position in which the strip is coplanar with its
wall to allow the containers to be nested while, in the second, the
strip is inwardly deflected to allow it to support an overlying
container.
I have used the term "strip" to refer herein to the load-supporting
members of the present invention, these members forming pedestals
against which the bottom of an overlying container may rest.
Preferably these pedestals are formed unitarily with the walls to
which they are attached by a hinged web, the latter being a
so-called hinge-foil and representing a portion of the wall or
reduced thickness formed during the compression molding, casting or
injection-molding process in which the container is formed from the
synthetic resin. The hinge thus is also unitarily and
monolithically part of the wall structure, the walls being
unitarily and monolithically formed with the upper rim of the
container and the continuous and preferably planar floor thereof.
An important point of the present invention is that the pedestal
strip occupies a minor fraction of the length of the wall in the
horizontal direction, whether this wall extends over the long leg
or the short leg of the rectangle. Furthermore, the hinge web
extends transversely to the length of the wall, i.e, in the
vertical direction when the container is stood with its bottom upon
a horizontal surface and thus the hinge axis lies generally
perpendicular to the bottom of the container. When I refer to a
slightly tapered construction of the container, I mean that the
rectangular plane or outline of the bottom of each container lies
within the rectangular outline of the top or rim thereof so that
the end walls and lateral wall are inclined inwardly from the rim
to the bottom. This allows the containers to be nested. Furthermore
the containers are preferably mirror-symmetrical about the
longitudinal and transverse median planes through the
container.
According to a more specific feature of the invention, the strips
or pedestals define the corners of the container and are
constituted by at least two hingedly interconnected and unitarily
formed strips, each belonging to one of the walls and hinged
thereto. The interconnected strip may define an outer corner of the
container in the outer positions of the strips but can be deflected
inwardly to provide a generally triangular pedestal reaching
inwardly to support the overlying container. Of course each strip
may also be subdivided into hingedly interconnected strips to
facilitate deflecting the pedestal inwardly past a dead-center
position. The pedestal may thus have three or five hinges. As
indicated, the pedestals may be provided at at least two locations,
e.g., in diagonally opposite relationship although at least three
pedestals are preferred, e.g., at three corners of the container.
In the more common case, four pedestals will be provided although
only three need be brought into play.
It should be noted that, to transform the container from a nesting
receptacle into a stacking receptacle, it is merely necessary to
deflect the corner pedestals inwardly to receive the overlying
container, this being done by hand or automatically in a packing
machine or the like.
In another embodiment of the invention, the strips are provided at
the corners of the container although they are not hingedly
interconnected. However, detents in the form of pins, knubs or the
like may be provided across which the strips may be resiliently
displaced to retain the two-leg pedestals at each corner in place.
The strips need not extend over the full height of the container or
its undisturbed storage compartment although it is preferred that
the pedestals rest in force-transmitting relationship with the
bottom of the container. Where the pedestals do not run the full
height of the undisturbed-storage compartment, they may be of
triangular configuration and form acute angles with the respective
walls or hinges to transfer force to the latter.
DESCRIPTION OF THE DRAWING
The above and other objects, features and advantages of the present
invention will become more readily apparent from the following
description, reference being mde to the accompanying drawing in
which:
FIG. 1 is a perspective view of a transport container having four
snap-action pedestals according to the invention;
FIG. 2 is a cross-sectional view taken along line II -- II of FIG.
1 showing the pedestal strips in their positions in which the
container is nestable;
FIG. 3 is a cross-section taken along the line III -- III of FIG. 1
showing the pedestal in a position in which it is adapted to
support the load of a similar container stacked thereon;
FIG. 4 is a cross-sectional view generally similar to FIG. 3 but
showing a different pedestal structure;
FIG. 5 is a section similar to FIG. 2 through a pedestal
arrangement using detents;
FIG. 6 is a view taken in the direction of the arrow VI of FIG.
5;
FIG. 7 is a view similar to FIG. 6 but showing another
configuration of the pedestal-forming strips;
FIG. 8 is a vertical section through a pair of nested containers
according to the invention; and
FIG. 9 is a similar section (showing the upper container in
elevation) of an arrangement in which the containers are
stacked.
SPECIFIC DESCRIPTION
Referring first to FIGS. 8 and 9 from which the operating states of
a container according to the invention will be apparent, it should
be noted that the basic container structure comprises a floor or
bottom 40 whose width in rectangular plan view is represented at W,
the container being formed unitarily with the vertical walls 41 and
42 which are tapered by an angle .alpha. of several degrees. The
corresponding inner dimension W' of the outwardly turned rim 43 of
the container is greater than W to accommodate the taper. It should
be apparent that this structure allows the container C.sub.1 to
nest within the container C.sub.2 if the end walls are similarly
tapered. The containers are identical and are formed along their
walls with ribs 44 which project inwardly to define channels 45
facing the exterior of the container. Since the channels 45 extend
downwardly and merge with the floor 40, the channel of an
underlying container can receive the reinforcing rib 44 of an
overlying container in the nested condition (FIG. 8) and for this
purpose a draft is imparted to the walls of the ribs. The latter
are described in greater detail in connection with FIGS. 1 - 7. The
corners of the containers C.sub.1 and C.sub.2 may be provided with
inwardly deflectable pedestals 46, the upper edges 47 of which are
separated by a distance D which is less than W and lie within the
outline of the bottom 40 so that they are able to support the
overlying container. The tops of these pedestals thus define a
compressionfree compartment K in which goods may be received
without compaction or compression by an overlying container. The
corner pedestals may be provided as described in connection with
FIGS. 1 - 7. To use the system of FIGS. 8 and 9, one merely
withdraws one of the nested containers C.sub.1 from the other
C.sub.2, deflects the corner pedestals inwardly, and places the
upper container C.sub.1 upon the lower.
Suitable containers for use as described in connection with FIGS. 8
and 9 can be provided as shown in FIG. 1. The upwardly open
box-like container 1 of this Figure is composed of injection-molded
synthetic resin with a monolithic structure including a bottom or
floor 2, sidewalls 3 - 6, reinforcing vertical ribs 7 (which also
define channels as noted earlier) and a peripheral outwardly turned
flange or rim 8. Members 2 - 8 thus are composed as a single
piece.
At the corners 9 and 10 between the walls, I provide snap-hinges
(which are shown in enlarged scale in FIGS. 2 and 3. Each
snap-hinge comprises a pair of pedestal strips 12 and 13
interconnected by a flexible ligature of synthetic resin 14 forming
the actual hinge piece and constituting a synthetic-resin foil or
film which is sufficiently flexible as to accommodate the
displacement of the hinge represented in FIGS. 2 and 3. The
pedestal pieces 12 and 13 are connected by respective flexible
ligatures 15 with the respective sidewalls 3, 4 and 3, 6
respectively. The ligatures thus are synthetic-resin strips
substantially thinner than the walls and extending along the
so-called hinge axes substantially perpendicular to the bottom 2.
Of course I may form the hinges separately, in which case members
12 and 13 may be connected with separately produced foils
adhesively bonded to the sidewalls.
The container of FIG. 1 is mirror-symmetrical about a transverse
median plane M.sub.1 and the longitudinal median plane M.sub.2.
In FIGS. 2 and 3, I show a snap-action hinge wherein the pedestal
strips 12 and 13 are generally coplanar with the walls 3 and 4 in
their outer or nonsupporting positions and have a total length
L.sub.1 - L.sub.2 which exceeds the normal distance L between the
hinges 15. The diagonal connecting the hinges 15 and represented at
T in FIG. 3, is a dead-center position through which the pedestal
is displaced. If the hinges 14, 15 are sufficiently thin and the
thermoplastic material sufficiently elastic to accommodate this
movement without rupture of the hinges, no special precautions must
be taken. In some cases, however, it will be necessary, immediately
after injection-molding of the container, to press the pedestals
inwardly (FIG. 3) to provide flexibility and elasticity in the
finished body.
In the position of the hinge 11 shown in FIG. 2, members 12 and 13
form the corner (corner 10 in FIG. 1) and lie outside the outline
of the bottom 2. The containers may be thus nested one within
another. In the arrangement shown in FIG. 3, however, the pedestals
11 lie within the outline of the bottom of the container so that
the bottom of an overlying container may rest thereon. The strips
12 and 13 may have a length S equal to the height K of the storage
compartment if force transmission from container bottom to
container bottom through the pedestals directly is required.
However, the system of FIG. 6 may also be employed.
In FIG. 4 I show a system in which the hinge 16 is provided with
four strips 17, 18, 19, 20 interconnected by ligatures 21 and
joined by the latter to the sidewalls 22 and 23. Here again the
total length of the sidewalls is greater than the distance between
the wall hinges so that the strips are deflected past a dead-center
position.
Another arrangement is shown in FIGS. 5 and 6 wherein detents 30 in
the form of studs, pins and knubs project upwardly from the bottom
31 of the container at the corner. The pedestal strips 25 and 26
are respectively hinged to the walls 27 and 28 but are not
connected together so that they may be swung inwardly individually
as shown in broken lines through 90.degree.. In this position, they
are held against self return by the studs 30 which are arranged at
the corners of a diamond. The other integrally molded studs 30
yieldably retain the members 25 and 26 against inward displacement.
Since the strips 25 and 26 are deflectable, only slight pressure is
necessary to overcome the resistance of the studs in displacing the
pedestal strips inwardly and outwardly.
In the system of FIG. 5, moreover, only a single strip may be
required to constitute the pedestal at each corner and it should be
evident that the studs may be provided along the upper rib of the
container. It is also possible as shown in FIG. 7 to provide the
studs on the underside of an overlying container 34, i.e., at the
bottom 33 thereof as shown at 32. The strips are here swung
inwardly and the upper container lowered in place. The strip 35
will, of course, swing out into coplanarity with its wall under the
elasticity of hing 37 of the lower container when the upper one is
removed. In this embodiment, moreover, the pedestal strip 35 has a
generally triangular configuration and the load forces are applied
to the wall of the container in the direction of the vector V.
The improvement described and illustraed is believed to admit of
many modifications within the ability of persons skilled in the
art, all such modifications being considered within the spirit and
scope of the invention except as limited by the appended
claims.
* * * * *