U.S. patent application number 17/425182 was filed with the patent office on 2022-04-21 for rotation support member for front panel/rear panel of foldable container.
This patent application is currently assigned to KOREA PALLET POOL CO., LTD. The applicant listed for this patent is KOREA PALLET POOL CO., LTD. Invention is credited to Shin Joon KANG, Nu Ree LEE, Yong Jun LEE, Byong Yoon SUH.
Application Number | 20220119194 17/425182 |
Document ID | / |
Family ID | |
Filed Date | 2022-04-21 |
View All Diagrams
United States Patent
Application |
20220119194 |
Kind Code |
A1 |
SUH; Byong Yoon ; et
al. |
April 21, 2022 |
ROTATION SUPPORT MEMBER FOR FRONT PANEL/REAR PANEL OF FOLDABLE
CONTAINER
Abstract
The present disclosure provides a rotation support member for
supporting a rotation operation of a front panel and a rear panel
in a container including the front panel and the rear panel
rotatably coupled to a bottom plate, and third and fourth torsion
bars serving as reference axes of rotation for the front panel and
the rear panel, in which the rotation support member includes: a
first rotation support member including one end fixedly coupled to
a post coupling point (220) of the front panel which is spaced
apart by a predetermined distance from a lower end of the front
panel, and the other end positioned at a bottom plate coupling
point (210) positioned on a side spaced apart by a predetermined
distance from a front end of the bottom plate; and a first rotation
support member including one end fixedly coupled to a post coupling
point (220) of the rear panel which is spaced apart by a
predetermined distance from the lower end of the rear panel, and
the other end positioned at a bottom plate coupling point (210)
positioned on a side spaced apart by a predetermined distance from
a rear end of the bottom plate, in which the other end of the first
rotation support member is coupled to the third torsion bar at the
bottom plate coupling point (210) such that the front panel is
rotated with respect to the third torsion bar, and the other end of
the second rotation support member is coupled to the fourth torsion
bar at the bottom plate coupling point (210) such that the rear
panel is rotated with respect to the fourth torsion bar.
Inventors: |
SUH; Byong Yoon; (Seoul,
KR) ; LEE; Yong Jun; (Cheonan-si, Chungcheongnam-do,
KR) ; KANG; Shin Joon; (Osan-si, Gyeonggi-do, KR)
; LEE; Nu Ree; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOREA PALLET POOL CO., LTD |
Seoul |
|
KR |
|
|
Assignee: |
KOREA PALLET POOL CO., LTD
Seoul
KR
|
Appl. No.: |
17/425182 |
Filed: |
May 14, 2019 |
PCT Filed: |
May 14, 2019 |
PCT NO: |
PCT/KR2019/005775 |
371 Date: |
July 22, 2021 |
International
Class: |
B65D 88/52 20060101
B65D088/52 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 23, 2019 |
KR |
10-2019-0008558 |
Claims
1. A rotation support member for supporting a rotation operation of
a front panel and a rear panel in a container comprising the front
panel and the rear panel rotatably coupled to a bottom plate, and
third and fourth torsion bars serving as reference axes of rotation
for the front panel and the rear panel, wherein the rotation
support member comprises: a first rotation support member including
one end fixedly coupled to a post coupling point (220) of the front
panel which is spaced apart by a predetermined distance from a
lower end of the front panel, and the other end positioned at a
bottom plate coupling point (210) positioned on a side spaced apart
by a predetermined distance from a front end of the bottom plate;
and a second rotation support member including one end fixedly
coupled to a post coupling point (220) of the rear panel which is
spaced apart by a predetermined distance from the lower end of the
rear panel, and the other end positioned at a bottom plate coupling
point (210) positioned on a side spaced apart by a predetermined
distance from a rear end of the bottom plate, wherein the other end
of the first rotation support member is coupled to the third
torsion bar at the bottom plate coupling point (210) such that the
front panel is rotated with respect to the third torsion bar, and
the other end of the second rotation support member is coupled to
the fourth torsion bar at the bottom plate coupling point (210)
such that the rear panel is rotated with respect to the fourth
torsion bar.
2. The rotation support member according to claim 1, wherein the
first rotation support member is coupled to and rotated integrally
with the front panel at the post coupling point, and the second
rotation support member is coupled to and rotated integrally with
the rear panel at the post coupling point.
3. The rotation support member according to claim 1, wherein the
first rotation support member has an L-shape including a parallel
member (200a) parallel to a ground and a vertical member (200b)
perpendicular to the ground when the front panel is in a stand-up
state, and the second rotation support member has an L-shape
including a parallel member (200a) parallel to a ground and a
vertical member (200b) perpendicular to the ground when the rear
panel is in a stand-up state.
4. The rotation support member according to claim 3, wherein the
parallel member has a length (L) such that a height of the
container in a folded state is 1/4 of a height of the container in
an unfolded state.
Description
BACKGROUND
Technical Field
[0001] The present disclosure relates to a member for supporting a
rotation of a panel in a foldable container, and more specifically,
to a technology for supporting a rotation operation of a front
panel and a rear panel, which have a large load among the panels of
the container, to enable stable stand-up of the front panel and the
rear panel and also a smooth folding rotation operation.
Background Art
[0002] In general, a container has a shape of a large box formed of
metal plates and is mainly used for cargo transportation. Such a
container is sized according to a certain standard and is widely
used for its advantage that it not only allows ease of cargo
storage and transport, but also can protect the cargo loaded
therein. Containers are transported individually by dedicated large
cargo vehicles or transported in large quantities by a dedicated
train or a dedicated vessel. However, when transported by the modes
of transport, whether the containers are loaded with cargo or empty
without cargo therein, they occupy the same space of transport.
[0003] Therefore, when the containers without the cargo loaded
therein are transferred to another place or stored in a certain
place, the containers in their fixed volume cause a problem that
they unnecessarily occupy a large volume, thus taking a large
amount of transportation space and transportation costs. In other
words, after the containers loaded with the cargo have transported
the cargo, when they are stored or retrieved in empty state, the
containers with such invariable volume take up a large amount of
space and costs for storage and transportation.
[0004] In particular, when transferring a container using a large
cargo vehicle, since one container is mounted on one cargo vehicle
and transported, transportation efficiency may decrease and
transportation cost may greatly increase. In addition, since the
container occupies a very large amount of space, when several
containers are stacked, there is a risk of an accident due to the
height of the stacked containers.
[0005] In order to improve this, in the related art, a foldable
container that can save stacking space and can be folded for easy
and convenient transportation of empty containers has been
disclosed.
[0006] A foldable container according to the related art has been
disclosed in Korean Patent Publication No. 10-1064803, Korean
Patent Publication No. 10-1439073, and Korean Patent Publication
No. 10-1489626. Referring to these, both side plates between the
bottom plate and the roof plate are configured as an upper plate
and a bottom plate, in which the upper plate and the bottom plate,
the upper plate and the roof plate, and the bottom plate and the
bottom plate are pivotally coupled to each other by a plurality of
hinge devices so as to be folded to each other. Such a hinge device
is configured to include hinge blocks provided on each of the
plates folded to each other, and connection blocks for connecting
these hinge blocks, in which the hinge blocks and the connection
blocks are hingedly coupled through hinge pins respectively.
[0007] However, since the foldable container according to the
related art includes, for the hinge device, the hinge blocks
installed on each of the plates to be folded to each other, the
connecting blocks connecting the respective hinge blocks, and the
hinge pins that hingedly couple the respective hinge blocks and the
connecting blocks, there are shortcomings that the entire structure
of the hinge device is complex, heavy, and not easy to manufacture
and mount.
SUMMARY
Technical Problem
[0008] In order to solve the problems of the related art described
above, an object of the present disclosure is to provide a
structure that allows the side walls of a foldable container to be
easily folded by manpower.
[0009] In addition, another object of the present disclosure is to
provide a structure for folding a side wall of a container, in
which, while a top plate is removed, a torsion bar is placed at a
lower end of the side wall panel and the torque of the torsion bar
is utilized to allow the side wall to be smoothly folded.
[0010] In addition, an object of the present disclosure is to
facilitate the folding and unfolding of the side wall by
accumulating elastic force in the torsion bar during the process of
folding the side wall of the container and utilizing the
accumulated elastic energy in the process of unfolding the side
wall of the container.
[0011] In addition, it is an object of the present disclosure to
provide a method for improving the lifespan of the torsion bar by
developing a technology capable of reducing twist angle of the
torsion bar involved in rotations of a front panel and a rear panel
since these have a considerably greater load.
Technical Solution
[0012] The present disclosure provides a rotation support member
for supporting a rotation operation of a front panel and a rear
panel in a container including the front panel and the rear panel
rotatably coupled to a bottom plate, and third and fourth torsion
bars serving as reference axes of rotation for the front panel and
the rear panel, in which the rotation support member includes: a
first rotation support member including one end fixedly coupled to
a post coupling point 220 of the front panel which is spaced apart
by a predetermined distance from a lower end of the front panel,
and the other end positioned at a bottom plate coupling point 210
positioned on a side spaced apart by a predetermined distance from
a front end of the bottom plate; and a first rotation support
member including one end fixedly coupled to a post coupling point
220 of the rear panel which is spaced apart by a predetermined
distance from the lower end of the rear panel, and the other end
positioned at a bottom plate coupling point 210 positioned on a
side spaced apart by a predetermined distance from a rear end of
the bottom plate, in which the other end of the first rotation
support member is coupled to the third torsion bar at the bottom
plate coupling point 210 such that the front panel is rotated with
respect to the third torsion bar, and the other end of the second
rotation support member is coupled to the fourth torsion bar at the
bottom plate coupling point 210 such that the rear panel is rotated
with respect to the fourth torsion bar.
[0013] The first rotation support member is coupled to and rotated
integrally with the front panel at the post coupling point, and the
second rotation support member is coupled to and rotated integrally
with the rear panel at the post coupling point.
[0014] The first rotation support member has an L-shape including a
parallel member 200a parallel to a ground and a vertical member
200b perpendicular to the ground when the front panel is in a
stand-up state, and the second rotation support member has an
L-shape including a parallel member 200a parallel to a ground and a
vertical member 200b perpendicular to the ground when the rear
panel is in a stand-up state.
[0015] The parallel member has a length L such that a height of the
container in a folded state is 1/4 of a height of the container in
an unfolded state.
Advantageous Effects
[0016] According to the present disclosure, with the structure
described above, after the top plate of the container is removed
with a forklift, the side wall panel can be easily folded simply by
manpower and the height can be reduced by 1/4 in the folded state
such that four containers can be folded and stacked, and thus the
effects of easy storage and movement of the containers are
provided.
[0017] In addition, with the structure of the rotation support
member, the front panel and the rear panel can stand up stably even
when no additional preliminary torque is applied to the torsion
bar, and the twist angle of the torsion bar in the folded state can
be reduced, resulting in a beneficial effect on the torsion bar
lifespan.
BRIEF DESCRIPTION OF THE DRAWING
[0018] FIG. 1 illustrates an overall appearance of a foldable
container according to the present disclosure.
[0019] FIG. 2 illustrates the foldable container from which a top
plate is removed according to the present disclosure.
[0020] FIG. 3 illustrates a first side panel of the foldable
container being folded according to the present disclosure.
[0021] FIG. 4 illustrates a second side panel of the foldable
container being folded according to the present disclosure.
[0022] FIG. 5 is a diagram illustrating a front panel of the
foldable container being folded according to the present
disclosure.
[0023] FIG. 6 illustrates a rear panel of the foldable container
being folded according to the present disclosure.
[0024] FIG. 7 illustrates the foldable container fully folded
according to the present disclosure.
[0025] FIG. 8 illustrates a structure of a torsion bar provided in
a longitudinal direction on a bottom plate of the foldable
container according to the present disclosure.
[0026] FIG. 9 is a graph showing the relative magnitudes of a
moment and a torque according to the present disclosure, in which
the moment is generated based on the weights of the first and
second side panels of the foldable container during folding, and
the torque is generated by the torsion bar.
[0027] FIG. 10 illustrates the overall process of folding and
unfolding the foldable container according to the present
disclosure.
[0028] FIG. 11 illustrates a partial lower portion of the bottom
plate of the foldable container according to the present
disclosure.
[0029] FIG. 12 illustrates a rotation support member of the
foldable container according to the present disclosure.
[0030] FIGS. 13 and 14 are explanatory diagrams illustrating the
operating principle of the rotation support member and the torsion
bar of the foldable container according to the present
disclosure.
BEST MODE
[0031] Hereinafter, embodiments of the present disclosure will be
described in detail with reference to the accompanying drawings. It
should be noted that, in adding reference numerals to the
constituent elements of the drawings, the same constituent elements
are denoted by the same reference numerals even if they are
illustrated in different drawings. In the following description of
the present disclosure, a detailed description of known functions
and configurations incorporated herein will be omitted when it may
make the subject matter of the present disclosure rather
unclear.
[0032] The objectives, specific advantages and novel features of
the present disclosure will become more apparent from the following
detailed description and the preferred embodiments, which are
associated with the accompanying drawings. In addition, terms
described herein are terms defined in consideration of functions in
the present invention, which may vary according to the intention or
convention of a user or an operator. Therefore, definitions of
these terms should be made based on the contents throughout the
present specification.
[0033] FIG. 1 illustrates an overall appearance of a foldable
container according to the present disclosure, in which the side
wall panel of the container is in a vertically unfolded state,
which will be referred to herein as an "unfolded state" for
convenience. FIG. 2 illustrates the foldable container from which a
top plate is removed according to the present disclosure, FIG. 3 is
a diagram illustrating a first side panel of the foldable container
being folded according to the present disclosure, FIG. 4
illustrates a second side panel of the foldable container being
folded according to the present disclosure, FIG. 5 illustrates the
front panel of the foldable container being folded according to the
present disclosure, and FIG. 6 illustrates a rear panel of the
foldable container being folded according to the present
disclosure, and FIG. 7 illustrates the foldable container fully
folded according to the present disclosure, which will be referred
to herein as a "folded state" for convenience. FIG. 8 illustrates a
structure of a torsion bar provided in a longitudinal direction on
a bottom plate of the foldable container according to the present
disclosure, FIG. 9 is a graph showing the relative magnitudes of a
moment and a torque according to the present disclosure, in which
the moment is generated based on the weights of the first and
second side panels of the foldable container during folding and the
torque is generated by the torsion bar, and FIG. 10 illustrates the
overall process of folding and unfolding the container. It is
designed such that the use of a forklift is necessary only in the
process of removing or lifting the top plate, while all other
operations are possible with human power. Since the forklift is
present anywhere in the field where containers are loaded or moved,
even when there are some operations that use the forklift, it will
not cause any problem in the efficiency of work.
[0034] [Foldable Container Structure and Folding Method]
[0035] A foldable container of the present disclosure (hereinafter,
it may be referred to as "container") has a bottom plate 110, a top
plate 120 spaced apart above the bottom plate 110, and side wall
panels 130 installed on both sides between the bottom plate 110 and
the top plate 120. The side wall panel 130 includes four
vertically-arranged panels, which will be referred to as a front
panel 131, a rear panel 135, a first side panel 137, and a second
side panel 139, respectively. Posts P for bearing the load of the
container in the vertical direction are provided on edges of the
rectangles of the front panel 131 and the rear panel 135,
respectively.
[0036] The feature of the foldable container according to the
present disclosure is that the four side wall panels 130 can be
simply folded by manpower using a torsion bar provided at the lower
end, while the top plate 120 is completely removed using a
forklift. That is, when the side wall panel is folded by the moment
due to its self weight, the torque generated from the twisting
torsion bar applies a rotational force opposite to the moment due
to self weight, thereby allowing the it to be folded smoothly.
[0037] First, a method for folding a container according to the
present disclosure will be described.
[0038] For the container of the present disclosure, the process of
lifting the top plate 120 using a forklift is performed first. A
plurality of coupling members 125, to which the forks of the
forklift are inserted and coupled, are provided on the top plate,
that is, on an upper surface of the top plate of the container in a
transverse direction. Hereinafter, the transverse direction of the
container refers to the width direction of the container, and the
longitudinal direction of the container refers to the direction
from the front panel toward the rear panel. In addition, FIG. 2
illustrates the top plate completely lifted up by the forklift
(illustration of the forklift is omitted for convenience of
description). The characteristic of the present disclosure is that
the top plate 120 is first completely separated from the side wall
panel 130 by the forklift, as illustrated in FIG. 2. This is
completely different from the related art where the folding
operation is performed with the top plate remaining attached to the
side wall panel. The top plate removed by the forklift is moved to
the side of the container and positioned.
[0039] Then, the first side panel 137 is folded as illustrated in
FIG. 3, and the second side panel 139 is folded over the first side
panel 137 as illustrated in FIG. 4. According to the present
disclosure, in order to fold the first and second side panels,
first and second torsion bars T1 and T2 are positioned under the
first and second side panels. This will be described with reference
to the detailed illustration in FIG. 8. Since the first side panel
and the second side panel are folded by the same principle as each
other and it is also the same that four of the first and second
torsion bars are arranged along the longitudinal direction of the
container, only the process of folding the first side panel will be
described below as an example.
[0040] Referring to FIG. 8, there is provided a fixture 110a that
is fixedly coupled to the bottom plate 110 of the container so as
not to rotate in the process of rotating of the first side panel
137. The fixture 110a is fixed to a frame of the bottom plate and
not rotated. In addition, there is provided a rotating body 137a
that is fixedly coupled to the first side panel 137 and rotated
together when the first side panel is rotated. In this example, the
"rotation" means an operation of pivoting of the side wall panel
based on the lower end in order to be folded. In addition, one end
of the first torsion bar T1 is coupled by serration to the fixture
110a and the other end is coupled by serration to the rotating body
137a. When the first side panel 137 is rotated to be folded, the
rotating body 137a is rotated, and as a result, the first torsion
bar T1 is twisted and rotational elastic energy is accumulated
(this is referred to as "torsion bar torque" for convenience). The
torsion bar torque applies a rotational force in the direction
opposite to the rotational force direction of the moment generated
by the self weight of the first side panel, thereby preventing the
first side panel from being suddenly folded by the self weight,
while ensuring a smooth folding operation.
[0041] The principle of the rotation of the first side panel, the
torque of the first torsion bar, and the like will be separately
described in detail in the [Rotation Operation of Side Panel and
Torsion Bar] provided below.
[0042] FIG. 5 illustrates the front panel of the foldable container
being folded according to the present disclosure, and FIG. 6
illustrates the rear panel of the foldable container being folded
according to the present disclosure.
[0043] According to the present disclosure, in order to fold the
front and rear panels, third and fourth torsion bars T3 and T4 are
positioned under the front and rear panels. Since the third torsion
bar positioned under the front panel and the fourth torsion bar
positioned under the rear panel have the same principle of
operation during rotation, and the third torsion bar and the fourth
torsion bar are the same that two are arranged along the transverse
direction of the container, only the process of folding the rear
panel 135 will be described below as an example. Meanwhile, the
principle of the rotation of the rear panel, the torque of the
fourth torsion bar, and the like will be separately described in
detail in the [Rotation Operation of Rear Panel and Torsion Bar]
provided below.
[0044] FIG. 7 illustrates the top plate 120 is placed by a forklift
onto the top of the container in the fully folded state, which will
be referred to herein as a "folded state" for convenience. In order
to place the top plate 120 in the correct position in the folded
state, in the present disclosure, L-shaped corner support members
150 positioned at four corners of the bottom plate 110 are
adopted.
[0045] Referring to FIG. 6, the corner support members 150 are
L-shaped members formed at the four corners of the bottom plate
110, and have a first support surface 151 and a second support
surface 153 that are perpendicular to each other. The corner
support members 150 serve to support, from the outside, the corner
ends of the posts P of the front panel and the rear panel when the
container is in the unfolded state, and serve to support the four
corners of the top plate 120 placed on the container when the
container is in the folded state.
[0046] [Rotation Operation of Side Panel and Torsion Bar]
[0047] The structure of the torsion bar of FIG. 8 and the graph of
FIG. 9 will be described. The graph of FIG. 9 shows the moment M
generated by the self weight of the container in the process of
changing the rotation angle of the bottom plate 110 from 0.degree.
to 90.degree., and the torsional elastic energy resulting from the
rotation of the first torsion bar, that is, the torsion bar torque
T. In the graph, the horizontal axis represents the rotation angle
of the first side panel of the container, and the vertical axis
represents the torque. Referring to the graph, the relationship of
the moment and the torque according to the angle in the rotation
process is divided into three sections: Section A, Section B, and
Section C.
[0048] Section A is a process of starting the folding operation of
the side wall of the container, and in this section, the torsion
bar torque T is formed to be greater than the moment M generated by
the self weight of the container. This can be achieved by mounting
the first torsion bar T1 that is twisted at a predetermined angle
in advance, with the first side panel 137 being in stand-up
position. That is, the first torsion bar is twisted by a
predetermined angle (about 7.degree. in the present disclosure) in
advance in the direction in which the first torsion bar will be
twisted when the first side panel is rotated (This will be referred
to herein as "preliminary torque" for convenience). The reason for
doing this is to ensure the stability of the folding process. That
is, this is to prevent the first side panel 137 from being suddenly
rotated and collapsed from the stand-up state. In this example, in
order to fold the first side panel, it is necessary to apply a
force from the outside, and to be specific, the force needs to be
applied up to an angle corresponding to the point X in the graph.
In the present disclosure, by selecting a torsion bar of an
appropriate specification, and the like, the amount of necessary
force is appropriately adjusted so as to allow a rotation up to the
X point by pushing only with human force.
[0049] Section B is a section in which the moment M due to the self
weight of the first side panel is greater than the torsion bar
torque T, and is a section in which the folding operation is
performed by the self weight without requiring a separate external
torque. However, the smaller the difference between the moment M
and the torsion bar torque T in this section (the smaller the size
of the arrow in the B section of the graph), the smoother the first
side panel folds.
[0050] Section C is a process in which the rotation operation of
the first side panel is finished, and in this section, the torsion
bar torque T is slightly larger than the moment M generated by the
self weight. That is, while it requires additional external force
to achieve the fully folded state, because the additional external
force is small, it is sufficient for a human to press the first
side panel from above.
[0051] According to the present disclosure, the torque value of the
torsion bar is appropriately selected in consideration of the
magnitude of the moment value generated by the self weight of the
side wall panel, such that the external power (torque) is required
only at the beginning and the end of the folding operation, and the
size of the required external power is also sufficiently adjustable
by human power.
[0052] According to the present disclosure, with the top plate
removed, the first side panel maintains the vertical position in a
self-supporting state due to the preliminary torque of the torsion
bar itself. Then, it requires only a little external force to
rotate it to the X point, after which the rotation operation is
automatically performed by the self weight of the side panel. Then,
it requires a human to apply the external force only in the last
predetermined section of the rotation operation to make the folded
state. In the present disclosure, the points X and Y were
appropriately selected in order to provide the necessary
preliminary torque while reducing Section B, that is, reducing the
size of the arrow.
[0053] [Rotation Operation of Rear Panel and Torsion Bar]
[0054] FIG. 11 illustrates a partial lower portion of the bottom
plate of the foldable container according to the present
disclosure, and illustrates the lower portion adjacent to the rear
panel 135. FIG. 12 illustrates a rotation support member according
to the present disclosure, and FIGS. 13 and 14 are explanatory
diagrams illustrating the operating principle of the rotation
support member and the torsion bar.
[0055] In general, since most of the vertical load of the container
is born by the post (P in FIG. 12) positioned on the side of the
front panel 131 and the rear panel 135, the strength of the front
panel 131 and the rear panel 135 is important, and therefore, the
load they receive is much greater than that of the first and second
side panels. Therefore, in order to enable the rotation operation
of the front panel and the rear panel by human force, the torsion
bar provided for this and its arrangement structure are important.
According to the present disclosure, in order to rotate the front
panel 131 and the rear panel 135, the third and fourth torsion bars
T3 and T4 are provided. Since the front panel 131 and the rear
panel 135 are the same as each other in both the rotation operation
and the principle, the rear panel 135 and the fourth torsion bar T4
will be described below as an example.
[0056] Two of the fourth torsion bars T4 are arranged side by side
on the bottom plate 110 of the container in the transverse
direction, and only one of them is illustrated in FIG. 11. One end
of the fourth torsion bar T4 is coupled by serration to a fixed
coupling part 110b fixed to the frame of the bottom plate 110, and
the other end of the fourth torsion bar is coupled to a rotation
support member 200 while passing through the outer frame of the
bottom plate.
[0057] The rotation support member is an L-shaped member, with one
end being coupled to a post coupling point 220 at the post P spaced
apart from the lower end of the rear panel by a predetermined
distance, and the other end being coupled to the fourth torsion bar
T4 at a bottom plate coupling point 210 located on the side spaced
apart from the end of the bottom plate by a predetermined distance
(it is fixedly coupled using a separate connecting member between
the fourth torsion bar and the other end). The corner of the post P
is supported from the outside by the corner support member 150.
[0058] As described above, the rear panel and the front panel are
subjected to a greater load than the side panel, while the width of
the container in the transverse direction is smaller than the
length in the longitudinal direction, and accordingly, since the
third and fourth torsion bars must have higher torsional torque, in
consideration of the lifespan of the third and fourth torsion bars
and also the load of the front panel and the rear panel, the
present disclosure adopts the L-shaped rotation support member for
their rotation operation.
[0059] Referring to the rotation operation of the rear panel 135,
the rotation operation is performed based on the third torsion bar
located on the side spaced apart from the end of the bottom plate
by a predetermined distance as the reference axis, which is
different from the rotation of the side panel that is performed
based on the axis located immediately thereunder. The rotation
support member has the following roles and functions.
[0060] <Ensuring Stability>
[0061] In the description of the rotation operation of the side
panel, it is described that the first and second torsion bars
twisted by a predetermined angle in advance are mounted to provide
the "preliminary torque" in order to ensure stability (to prevent
the side panel from being suddenly rotated and collapsed from the
stand-up state).
[0062] However, stability is ensured by the rotation support member
200 without requiring the "preliminary torque" to be applied to the
fourth torsion bar T4 involved in the rotation of the rear
panel.
[0063] That is, in FIG. 13, the rear panel is supported by the
corner support member 150 supporting the outer corner of the lower
end thereof, so that the rotation in the direction of the arrow A
is constrained, and further, the rotation in the direction B is
also constrained by the rotation support member 200 and its self
load (that is, in the absence of the rotation support member,
rotation occurs in the direction B). For the side panel, the
preliminary torque is applied to the torsion bar to prevent the
inward folding operation, but for this rear panel, even when the
preliminary torque is not applied to the torsion bar, the rotation
operation is kept from occurring, thereby ensuring stability. In
other words, in order for the rear panel 135 to be rotated inward,
it requires to apply the external force up to the point where the
post coupling point 220 is located directly above the bottom plate
coupling point 210, and therefore, the rear panel is maintained in
a stable state unless the external force is applied (FIG. 14). In
the actual operation of folding the rear panel, the rear panel is
rotated by pushing from the outside by the power of a human by the
angle .theta. shown in FIG. 14. When the rear panel is rotated
beyond the angle shown in FIG. 14, the rear panel is gently folded
by the mutual relationship between the moment M by the self weight
of the rear panel and the torsion bar torque T by the fourth
torsion bar, which has already been described with reference to the
folding operation of the side panel.
[0064] <Ensuring Durability of Torsion Bar>
[0065] Since it is difficult to expect the effect of torsional
elastic energy any more when the twist angle of the torsion bar
exceeds the point where plastic deformation occurs, the torsion bar
should be twisted only at an angle below which plastic deformation
does not occur, and even at an angle at which plastic deformation
does not occur, it is still advantageous to prevent excessive
twisting in consideration of the lifespan.
[0066] It has been described that according to the present
disclosure, stability is ensured by the rotation support member 200
even without the "preliminary torque" applied to the fourth torsion
bar of the container. This has the effect of reducing the amount of
twist of the fourth torsion bar as a result. For example, when a
7.degree. torsion angle is provided in the initial state (side
panel stand-up state) to provide the preliminary torque to the side
panel, in the folded state in which the side panel is completely
rotated by 90.degree., there is the effect that the first and
second torsion bars have a torsion angle of 97.degree..
[0067] Meanwhile, according to the present disclosure, the fourth
torsion bar of the rear panel does not have a preliminary torque
due to the existence of the rotation support member 200, and the
fourth torsion bar is in a state where there is no torsion in the
state illustrated in FIG. 14 (in this state, the post coupling
point 220 is located directly above the bottom plate coupling point
210). In this state, when the rear panel is completely rotated and
folded, the twist angle of the fourth torsion bar is (90-.theta.),
and the maximum twist angle is significantly reduced. This leads to
the effect of increasing the life of the fourth torsion bar.
[0068] The rotation support member is provided equally on the front
panel and the rear panel, and includes a first rotation support
member coupled to the front panel and a second rotation support
member coupled to the rear panel.
[0069] The present disclosure has been described in detail.
However, it should be understood that the detailed description and
specific examples, while indicating preferred embodiments of the
disclosure, are given by way of illustration only, since various
changes and modifications within the scope of the disclosure will
become apparent to those skilled in the art from this detailed
description.
* * * * *