EP1655232B1

EP1655232B1 - Folding container

Info

Publication number: EP1655232B1
Application number: EP04771443A
Authority: EP
Inventors: Toshiya MITSUBISHI PLASTICS INC. NAMAZUE; Kazuhisa MITSUBISHI PLASTICS INC. AONO
Original assignee: Mitsubishi Plastics Inc
Current assignee: Mitsubishi Plastics Inc
Priority date: 2003-08-13
Filing date: 2004-08-10
Publication date: 2012-09-05
Anticipated expiration: 2024-08-10
Also published as: WO2005016770A1; CN100488846C; JP4008472B2; JPWO2005016770A1; EP1655232A1; EP1655232A4; CN1835868A

Description

The present invention relates to a collapsible container in accordance with the preamble of claim 1, and more particularly to a collapsable container in which each pair of opposed first sidewall plates and second sidewall plates along all edges of a quadrilateral base plate can be collapsed by being superimposed on the top face of the base plate.

Background Art

A collapsable container has been known, in which a long edge plate is rotatably coupled to each of a pair of opposed long edges of a quadrilateral base plate; and a short edge plate is rotatably coupled to each of a pair of short edges, which can be collapsed by superimposing the short edge plates and long edge plates on the top face of the base plate when not used.
When constructing the collapsible container, between both inner ends of both long edge plates standing up generally perpendicularly from the base plate, each end of the short edge plate standing up later is held. At this time, each short edge plate prevents both long edge plates from falling inside. In order to prevent the long edge plate and short edge plate from falling outside, the long edge plate and the short edge plate each are locked in a locking part. Also, each engage member appearing from the ends of the short edge plate is engaged with the long edge plate so as to prevent the short edge plate from falling inside (for example, see Japanese Unexamined Patent Publication No. 2003-165536 ). Document US 2003/0000950 , which accords with the preamble of claim 1, describes a foldable transportation container comprising a rectangular bottom, and a pair of first side walls and a pair of second side walls. Rotating means are provided on the lower ends of the side walls. And slidable engagement portions are provided on the outside face of the first side walls.

Disclosure of the Invention

Problem to be solved by the Invention

It has been often the case that an engagement structure of the long edge plate and short edge plate is complicated in a conventional collapsable container. It also often happens that both hands are necessary for disengagement and that unnatural finger movement is required for collapsing the short edge plate.
Accordingly, it is an object of the present invention to provide a collapsable container with a simple structure in which the short edge plate can be collapsed smoothly and furthermore, with an engagement structure in which engagement is not accidentally disengaged.

Means for Solving the Problem

In order to achieve the above object, a collapsible container of the present invention comprises a quadrilateral base plate; a pair of first sidewall plates in which each lower edge of the base plate is rotatably coupled to a pair of opposed first edges; and a pair of second sidewall plates in which each lower edge of the base plate is rotatably coupled to a pair of opposed second edges. The collapsible container is collapsed by superimposing the second sidewall plate and the first sidewall plate in this order on the top face of the base plate when collapsing. When constructing, the collapsable container is constructed by holding both ends of the second sidewall plate between both inner ends of both first sidewall plates standing up from the base plate. In this constructed state, the state is maintained by engaging a pair of latch members provided on the upper edge of the second sidewall plate so as to protrude from both ends of the second sidewall plate with a latch receiver provided on the first sidewall plate. The latch member, which is provided so as to be slidable in parallel with the upper edge of the second sidewall plate, comprises a pair of latch bars in which each tip thereof can protrude from each end face of the second sidewall plate; an operating bar disposed in an upper central portion of the second sidewall plate, in parallel with the upper edge; a guiding part for guiding the operating bar to move vertically; operational-direction conversion means for converting the vertical movement of the operating bar into the movement in a direction in which each latch bar slides; and urging means for urging at least either one of the operating bar and the latch bar in a direction in which the tip of each latch bar protrudes from the end face of the second sidewall plate. The operational-direction conversion means is formed so as to convert the downward movement of the operating bar into the movement in a direction in which each latch bar moves toward the center of the second sidewall plate so that each latch bar tip separates from the latch receiver.
In the above configuration, the operational-direction conversion means comprises a pair of right and left coupling pieces for coupling each end of the operating bar to a respective base end of the pair of latch bars. Each of the pull of coupling piece is coupled to the base end of a respective latch bar and a respective end of the operating bar through a first bending portion bent into a general V-shape toward the upper edge of the second sidewall plate and a respective end of the second sidewall plate from the base end of a respective latch bar and a second bending portion bent into a general V-shape toward the lower edge of the second sidewall plate and the center of the second sidewall plate from a respective end of the operating bar. Both bending portions are bent at an acute angle by the downward movement of the operating bar so that both latch bars move toward the center of the second sidewall plate. The urging means urges the operating bar upward by the resilience obtained by bending both bending portions at an acute angle, and urges each latch bar so that the tip of the latch bar protrudes from the end face of the second sidewall plate.
The latch member is different from the second sidewall plate in colour tone. In an upper edge top face piece of the second sidewall plate, a notch is provided so as to expose a part of the top face of the operating bar to an upper portion of the second sidewall plate. The top face of the operating bar exposed from the notch is located at a position lower than the top face of the upper edge top face piece of the second sidewall plate. The top face of the operating bar exposed from the notch has irregularities for slip resistance.
The guiding part has a cross rib therethrough formed outside the second sidewall plate. At the lower end of the guiding part extending through the cross rib, a gripping piece is provided which vertically moves integrally with the operating bar. The underside of the gripping piece is generally flush with the underside of the cross rib.
The urging means comprises a spring piece which protrudes from the latch bar toward the upper edge of the second sidewall plate; and a spring receiver which protrudes downward from the upper edge of the second sidewall plate so as to be slidingly in contact with the side face of the spring piece on the base end side. When the latch bar moves toward the center of the second sidewall plate, the side face of the spring piece on the base end side is slidingly brought into contact with the spring receiver, thereby deforming the spring piece elastically. The resilience of the elastically deformed spring piece urges the latch bar in a direction in which the tip of the latch bar protrudes from the end face of the second sidewall plate.
The urging means comprises a spring piece which protrudes from the underside of the operating bar down the second sidewall plate; and a spring receiver which protrudes outside the second sidewall plate so as to be in sliding contact with the underside of the spring piece. When the operating bar moves downward, the underside of the spring piece is pressed to be in contact with the spring receiver, thereby deforming the spring piece elastically. The resilience of the elastically deformed spring piece urges the operating bar up the second sidewall plate.
A U-shaped groove is provided extending continuously from the top face of a periphery of the base plate to the inner surface of an upstanding piece standing up from a periphery of the base plate.

Effect of the Invention

In the collapsible container of the present invention, when collapsing the constructed container, in order to disengage the engagement of the latch bar and the latch receiver, it is only necessary to push the operating bar provided at an upper central portion of the second sidewall plate to move downward. Therefore, the second sidewall plate can be collapsed easily and smoothly.
By coupling the base end of both latch bars and both ends of the operating bar through the coupling piece having the first bending portion and second bending portion, the operational-direction conversion means and the urging means can be increased.
By making colour tone of the latch member different from that of the second sidewall plate, the visibility of the latch member can be increased.
By providing a notch in the upper edge top face piece of the second sidewall plate so as to expose a part of the top face of the operating bar, the visibility and usability of the operating bar can be increased. The top face of the operating bar is exposed at a position lower than the top face of the upper edge top face piece of the second sidewall plate so that the position of the operating bar can be identified easily with a finger. Irregularities are provided for slip resistance on the top face of the operating bar exposed from the notch so as to prevent a finger from slipping when pressing the operating bar down.
By providing a gripping piece at the lower end of the guiding part so that the operating bar and the gripping piece are vertically held with a thumb and fingers when lifting the constructed collapsible container, the operating bar can be prevented from moving downward. By forming the underside of the gripping piece generally flush with the underside of the cross rib, fingers except a thumb can be put on the gripping piece underside and the cross rib underside without discomfort when lifting the constructed collapsible container.
By forming the urging means by the spring piece and the spring receiver provided in the latch bar and the second sidewall plate respectively, a more reliable urging force can be brought about.
By providing a U-shaped groove on the top face of a periphery of the base plate and the inner surface of the upstanding piece standing up from a periphery of the base plate, a resin plate or the like spreading on the base plate can be removed easily.

Brief Description of the Drawings

Figs. 1 to 13 show one embodiment of a collapsable container according to the present invention. In the collapsable container, a first edge corresponds to a long edge, a second edge to a short edge, a first sidewall plate to long edge plate, and a second sidewall plate to a short edge plate.
Figs. 1 to 4 show the collapsable container in a constructed state in which a latch member engages with a latch receiver.
Fig. 1 is a front view of one embodiment of the present invention showing the constructed collapsable container seen from the side of the short edge;
Likewise, Fig. 2 is a sectional plan view of a substantial part showing a state of the latch member and the latch receiver;
Likewise, Fig. 3 is a perspective view of the substantial part;
Likewise, Fig. 4 is a cross-sectional view of the substantial part;
Likewise, Fig. 5 is a front view seen from the short edge side, showing a state in which the engagement of the latch member and the latch receiver is disengaged;
Likewise, Fig. 6 is a sectional plan view of a substantial part showing a state of a latch and the latch receiver;
Likewise, Fig. 7 is a perspective view of the substantial part;
Likewise, Fig. 8 is a perspective view showing the collapsible container in a constructed state;
Likewise, Fig. 9 is a perspective view showing the collapsable container in a collapsed state;
Likewise, Fig. 10 is a longitudinal sectional view of the coupling portion between a base plate and a long edge plate in a constructed state;
Likewise, Fig. 11 is a longitudinal sectional view of the coupling portion between the base plate and the long edge plate in a collapsed state;
Likewise, Fig. 12 is a plan view of the coupling portion between the base plate and the long edge plate in the collapsed state;
Likewise, Fig. 13 is a perspective view of a substantial part showing the relation between the long edge plate and the short edge plate;

Fig. 14 is a perspective view showing another exemplary shape of the top face of the operating bar;
Fig. 15 is a perspective view showing still another exemplary shape of the top face of the operating bar;
Fig. 16 is a front view of a substantial part in which the latch member engages with the latch receiver; and
Fig. 17 is a front view of a substantial part in which the engagement of the latch member and the latch receiver is disengaged.

Explanations of Numerals

11: Collapsible container
12: Base plate
12a: Long-edge-side upstanding piece
12b: Short-edge-side upstanding piece
12c: U-shaped groove
13: Long edge plate
14: Short Edge plate
14a: Upper edge top face piece
14b: Cross rib
14c: Top face
14d: Underside
14e: Finger hooking piece
15: Hinge receiver
16: Hinge pin
17: Locking part
18: Engagement part
21: Locking hole
22: Locking protrusion
23: Latch member
24: Latch receiver
25: Latch bar
25a: Tapered face
26: Operating bar
26a: Top face
27: Spring member
28: Guiding part
29: Gripping piece
29a: Underside
31: Notch
32: Guiding piece
33: Opening
34: Coupling piece
35: First bending portion
36: Second bending portion
41: Protrusion
42: Rib
51: Spring piece
52: Spring receiver
53: Spring piece

Best Mode for carrying out the Invention

First, in Figs. 8 to 13, a collapsable container 11 comprises a quadrilateral base plate 12 having a pair of opposed long-edge-side upstanding pieces 12a and a pair of opposed short-edge-side upstanding pieces 12b; a pair of long edge plates 13,13 whose lower edges are rotatably coupled to the opposed long-edge-side upstanding pieces 12a of the base plate 12; and a pair of short edge plates 14,14 whose lower edges are rotatably coupled to the opposed short-edge-side upstanding pieces 12b of the base plate 12. The long-edge-side upstanding piece 12a stands higher than the short-edge-side upstanding piece 12b. The collapsable container 11 is formed so as to become a box opening upward when being constructed, in a state that each end of both short edge plates 14, 14 is held between both inner ends of the long edge plates 13, 13.
A U-shaped groove 12c is provided in a part of the base plate 12, extending continuously from the top face of a periphery of the base plate 12 to the inner surface of the long-edge-side upstanding piece 12a. A finger is inserted into the U-shaped groove 12c so that a resin plate or the like spreading on the base plate 12 can be removed easily.
When collapsing the constructed collapsible container 11, first, both short edge plates 14, 14 coupled to the short-edge-side upstanding piece 12b standing lower are collapsed on the top face of the base plate 12. Next, each of the long edge plates 13, 13 coupled to the long-edge-side upstanding piece 12a is collapsed by being superimposed on the short edge plates 14, 14. This brings about the state shown in Fig. 9, in which the collapsible container 11 has been collapsed. When constructing the collapsed collapsible container 11, both long edge plates 13, 13 are stood generally perpendicularly to the base plate 12, and both short edge plates 14, 14 are then stood generally perpendicularly to the base plate 12. This procedure brings about the state shown in Fig. 8, in which the collapsible container 1 has been constructed.
As shown in Figs. 10 to 12, the coupling portion between the base plate 12 and the long edge plate 13 has a structure in which a horizontal hinge pin 16 provided at a lower portion of the long edge plate 13 is rotatably fit in a hinge receiver 15 provided in the long-edge-side upstanding piece 12a. The hinge pin 16 is provided on both side faces of the hinge plate 16a protruding from a lower portion of the long edge plate 13. The hinge receiver 15 comprises a wider opening 15b into which the hinge pin 16 provided in a top board 15a of the long-edge-side upstanding piece 12a; and a narrower opening 15d into which a hinge plate 16a provided in an inner wall 15c is inserted. From the inner container side of an outer wall 15e, a support plate 15f protrudes for supporting the tip of the hinge plate 16a. On the container outer side of the inner wall 15c, an engaging protrusion 15g with which the hinge pin 16 engages is provided.
The hinge pin 16 is inserted into the hinge receiver 15 through the opening 15b so as to elastically deform the inner wall 15c having the engaging protrusion 15g toward the inside of the container to be engaged with the underside of the engaging protrusion 15g rotatably, beyond the engaging protrusion 15g. This rotatably couples the long edge plate 13 to the base plate 12 so as to bring the top face of the long-edge-side upstanding piece 12a into contact with the underside of the long edge plate 13 for construction, thereby preventing the long edge plate 13 from falling outside the container.
The coupling between the base plate 12 and the short edge plate 14 has the same structure as the coupling with the long edge plate 13. It should be noted that the hinge receiver 15 of the long-edge-side upstanding piece 12a is provided at a position higher than the side of the short-edge-side upstanding piece 12b due to the positional relation between the long edge plate 13 and the short edge plate 14 for collapsing.
As shown in Fig. 13, in a portion where the long edge plate 13 is in contact with the short edge plate 14, a locking part 17 and an engagement part 18 for maintaining the long edge plate 13 and the short edge plate 14 in a constructed state are provided. The locking part 17 comprises two locking holes 21 each located above and below, protruding from the end of the long edge plate 13 toward the short edge plate 14; and locking protrusions 22 at positions corresponding to the locking holes 21, protruding from the outside of the short edge plate 14. Each locking protrusion 22 is fit in each locking hole 21 for construction, thereby preventing the long edge plate 13 and the short edge plate 14 falling outside.
The engagement part 18 comprises a latch member 23 provided on the upper edge of the short edge plate 14 and a latch receiver 24 provided on the inner surface of the upper portion of the long edge plate 13. The tip of the latch member 23 protrudes from the end face of the short edge plate 14 so as to engage with the latch receiver 24, thereby preventing the short edge plate 14 from falling inside. The latch member 23 is led into the short edge plate 14 to disengage the engagement with the latch receiver 24 so that the short edge plate 14 can be folded inside.
As shown in Figs.1 to 7, the latch member 23 is different from the short edge plate 14 in colour tone. The latch member 23 comprises a pair of latch bars 25, 25 slidably provided along the top face of a cross rib 14b in parallel with the upper edge top face piece 14a of the short edge plate 14; an operating bar 26 provided along the underside of the upper edge top face piece 14a; a spring member 27 for coupling both ends of the operating bar 26 to the base end of both latch bars 25; a guiding part 28 for guiding the operating bar 26 to move vertically; and a gripping piece 29 provided at the lower end of the guiding part 28.
At a central portion of the upper edge top face piece 14a, a notch 31 is provided so as to expose a top face 26a of the operating bar 26 to an upper portion of the short edge plate 14. At a central portion of the cross rib 14b, an opening 33 through which the guiding part 28 and the gripping piece 29 extend is provided. A guiding piece 32 for holding the guiding part 28 so as to move vertically is provided on both sides of the opening 33. As shown in Fig.4, the top face 26a of the operating bar 26 is exposed at a position lower than a top face 14c of the upper edge top face piece 14a so that the top face 26a of the operating bar 26 and the top face 14c of the upper edge top face piece 14a are different in level. This enables the position of the operating bar 26 to be identified easily with a finger.
The underside 29a of the gripping piece 29 is generally flush with the underside 14d of the cross rib 14b, and a finger hooking piece 14e protruding downward is provided at an outer end of the cross rib 14b. The underside 14d of the cross rib 14b is thus generally flush with the underside 29a of the gripping piece 29 so that fingers except a thumb can be put on the underside 14d of the cross rib 14b and the underside 29a of the gripping piece 29 in a balanced manner when lifting the constructed collapsible container 11 by getting hold of a central portion between the upper edge top face piece 14a of the short edge plate 14 and the cross rib 14b.
Furthermore, even when the top face 26a of the operating bar 26 is pressed with a thumb through the notch 31 thereby pressing down the operating bar 26, since the operating bar 26 and the gripping piece 29 are held vertically between a thumb and fingers, the operating bar 26 does not move downward. Therefore, the engaged latch member 23 is not accidentally disengaged. Also, the collapsable container 11 can be lifted easily with fingers put on the finger hooking piece 14e.
The spring member 27 functions not only as urging means but also as operational-direction conversion means. The spring member 27 comprises a first bending portion 35 bent into a general V-shape, provided at both ends of the coupling piece 34, from the base end of both latch bars 25, both toward the upper edge and toward both ends of the short edge plate; and a second bending portion 36 bent into a general V-shape, from both ends of the operating bar 26, both toward the lower edge and toward the center of the short edge plate. The bending portions 35, 36 each have springing force against the bending direction (toward the extending direction). Therefore, the springing force of the spring member 27 urges the latch bar 25 in a direction to protrude from the end face of the short edge plate 14, and urges the operating bar 26 upward.
Under normal conditions, as shown in Figs. 1 to 3, the operating bar 26 is pressed against the underside of the upper edge top face piece 14a by the urging force of the spring member 27. In both latch bars 25, the shape and size of every part are set so that each tapered face 25a outside the tip protrudes from the end face of the short edge plate 14.
When constructing the collapsible container 11, if the tapered face 25a of the tip of the latch bar 25 makes contact with the outer face of the latch receiver 24, the latch bar 25 is pressed into the short edge plate 14 against the urging force of the spring member 27. Then, when the tip of the latch bar 25 passes through the latch receiver 24, the latch bar 25 is protruded from the end face of the short edge plate 14 by the urging force of the spring member 27 as urging means, thereby engaging the latch bar 25 and the latch receiver 24 automatically.
When collapsing the constructed collapsible container 11, the operating bar 26 exposed to the notch 31 is pressed down avoiding contact with the gripping piece 29. As shown in Figs.5 to 7, this enables the spring member 27 to function as an operational-direction conversion means that both bending portions 35, 36 are bent at an acute angle and that the coupling piece 34 is collapsed under the operating bar 26. This moves both latch bars 25 toward the center of the short edge plate so that the tip enters the short edge plate 14; the latch bar tip separates from the latch receiver 24 thereby disengaging the engaged state; and the short edge plate 14 can then be collapsed inside.
Therefore, in order to construct the collapsible container 11, it is only necessary to stand the long edge plate 13 up and then stand the short edge plate 14 up. The locking part 17 is locked and the engagement part 18 is engaged automatically at the same time. For collapsing the collapsible container 11, it is only necessary to press the operating bar 26 down through the notch 31 in the short edge plate 14 in order to fold the short edge plate 14 inside. The collapsible container 11, therefore, can be constructed and collapsed extremely easily.
Furthermore, since the latch member 23 is different from the short edge plate 14 in color tone, the operating bar 26 can be identified easily, thereby increasing the usability for collapsing. Also, since the top face 26a of the operating bar 26 and the top face 14c of the upper edge top face piece 14a are different in level, even when catching hold of a portion close to the notch 31 for handling, the operating bar 26 is seldom touched directly, thereby preventing the operating bar 26 from being pressed down by mistake. In addition, when stacking the constructed collapsible containers 11, the operating bar 26 is hidden by a flange under the upper collapsible container 11, thereby preventing the stacked containers from collapsing caused by operating the operating bar 26 by mistake.
As shown in Fig. 14 and Fig. 15, small protrusions 41 (Fig. 14), embossing or a plurality or multiple of small ribs 42 (Fig. 15) are provided on the top face of the operating bar 26, thereby preventing a finger from slipping when pressing the operating bar 26 down, so that usability can be increased.
For the urging means, in addition to the spring member 27, as shown in Fig. 16 and Fig. 17, a spring piece 51 protruding from the latch bar 25 toward the upper edge and a spring receiver 52 protruding downward from the upper edge top face piece 14a may be formed so that the spring piece 51 is deformed elastically when the latch bar 25 moves toward the center of the short edge plate while being slidingly in contact with the spring receiver 52, thereby urging the latch bar 25 in the protruding direction by the resilience of the spring piece 51.
Also, an arc-shaped spring piece 53 protruding downward from the underside of the operating bar 26 and the side face (underside) of the spring piece 53 pressed to be in contact with the top face of the cross rib 14b as a spring receiver may be formed so that the spring piece 53 is deformed elastically when the operating bar 26 moves downward, thereby urging the operating bar 26 upward by the resilience of the spring piece 53.
The collapsible container in this embodiment is a container in which the first edge corresponds to the long edge, the second edge to the short edge, the first sidewall plate to the long edge plate, and the second sidewall plate to the short edge plate. In addition, it may be a container in which the first edge corresponds to the short edge, the second edge to the long edge, the first sidewall plate to the short edge plate and the second sidewall plate to the long edge plate.

Claims

A collapsable container which comprises a quadrilateral base plate (12; a pair of first sidewall plates (13) in which each lower edge of the base plate (12) is rotably coupled to a pair of opposed first edges; and a pair of second sidewall plates (14; in which each lower edge of the base plate (12) is rotatably coupled to a pair of opposed second edges, formed so as to be collapsed by superimposing said second sidewall plate (14) and said first sidewall plate (13) in this order on a top face of the base plat (12) when collapsing; so as to be constructed by holding both ends of each of the second sidewall plates (14) between both inner ends of both first sidewall plates (14) standing up from the base plate (12) when constructing, and so as to maintain the constructed state by engaging a pair of latch members (23) provided on an upper edge of said second sidewall plate (14) so as to protrude from both ends of the second sidewall plate (14) with a latch receiver (24) provided on the first sidewall plate (13), wherein:
said latch member (23) provided to be slidable in parallel with the upper edge of the second sidewall plate (14), comprises a pair of latch bars (25) in which each tip can protrude from an end face of the second sidewall plate (14); an operating bar (26) disposed in an upper central portion of the second sidewall plate (14), in parallel with the upper edge; a guiding part (28) for guiding the operating bar (26) to move vertically; operational-direction conversion means converting vertical movement of the operating bar (26) into movement in which each latch bar (25) slides; and urging means for urging at least either one of the operating bar (26) and the latch bar (25) in a direction in which each latch bar tip protrudes from the end face of the second sidewall plate (14), characterised in that

said operational-direction conversion means comprises a pair of right and left coupling pieces (34) for coupling each end of said operating bar (26) to a respective base end of said pair of latch bars (25),

each of the pair of coupling pieces (34) iscoupled to the base end of a respective latch bar (25) and a respective end of the operating bar (26) through a first bending portion (35) bent into a general V-shape from the base end of said respective latch bar(25) both toward the upper edge of the second sidewall plate (14) and toward a respective end of the second sidewall plate (14); and through a second bending portion (36) bent into a general V-shape from said respective end of the operating bar (26), both toward a lower edge of the second sidewall plate (14) and toward the center of the second sidewall plate (14),

both bending portions (35, 36) are bent at an acute angle by downward movement of said operating bar (26) so that both latch bars (25) move toward the center of the second sidewall plate (14), and

said urging means urges said operating bar (26) upward by resilience obtained by bending both bending portions (35, 36) at an acute angle, and urges the latch bar (25) so that each latch bar tip protrudes from the end face of the second sidewall plate (14).
The collapsible container according to claim 1, wherein said latch member (23) is different from said second sidewall plate (14) in colour tone.
The collapsible container according to claim 1, wherein a notch (31) is provided in an upper edge top face piece (14a) of said second sidewall plate (14) so as to expose a part of the top face (26a) of said operating bar (26) to an upper portion of the second sidewall plate (14).
The collapsible container according to claim 3, wherein the top face (26a) of said operating bar (26) exposed from said notch (31) is located at a position bwer than a top face of the upper edge top face piece (14a) of said second sidewall plate (14).
The collapsible container according to claim 3, wherein the top face (26a) of said operating bar (26) exposed from said notch (31) has irregularities for slip resistance.
The collapsible container according to claim 1, wherein said guiding part (28) has a cross rib (14b) therethrough formed outside said second sidewall plate (14) and a gripping piece (29) which vertically moves integrally with said operating bar (26), at a lower end of the guiding part (29) extending through the cross rib (14b).
The collapsible container according to claim 6, wherein an underside (29a) of said gripping piece (29) is generally flush with an underside (14d) of said cross rib (14b).
The collapsible container according to claim 1, wherein:
said urging means comprises a spring piece (51) protruding from said latch bar (25) toward the upper edge of said second sidewall plate (14) and a spring receiver (52) protruding downward from the upper edge of said second sidewall plate (14) so as to be slidingly in contact with a side face of the spring piece (51) on the base end side,

when said latch bar (25) moves toward the center of the second sidewall plate (14), the side face of the spring piece (51) on the base end side is slidingly brought into contact with said spring receiver (52), thereby deforming the spring piece (51) elastically, and

resilience of the elastically deformed spring piece (51) urges the latch bar (25) in a direction in which said latch bar tip protrudes from the end face of the second sidewall plate (14).
The collapsible container according to claim 1, wherein:
said urging means comprises a spring piece (53) protruding from an underside of said operating bar (26) down said second sidewall plate (14) and a spring receiver protruding outside the second sidewall plate (14) so as to be in sliding contact with an underside of the spring piece (53),

when said operating bar (26) moves downward, the underside of said spring piece (53) is pressed to be in contact with said spring receiver, thereby deforming the spring piece (53) elastically, and

resilience of the elastically deformed spring piece (53) urges said operating bar (26) up said second sidewall plate (14).
The collapsible container according to claim 1, wherein a U-shaped groove (12c) is provided extending continuously from a top face of a periphery of said base plate (12) to an inner surface of an upstanding piece (12a) standing up from a periphery of the base plate (12).