AU681964B2 - Torsional linkage for controlling movement of a gate or panel of a collapsible container - Google Patents

Description

WO 95/30586 PCT/AU9500257 1 TORSIONAL LINKAGE FOR CONTROLLING MOVEMENT OF A GATE OR PANEL OF A COLLAPSIBLE CONTAINER This invention relates to a linkage mechanism for controlling the movement of a swinging gate or panel, and which has particular application for use in a collapsible storage container.

Collapsible storage containers comprising front, rear and side panels or gates which are either permanently or releasably hinged to a pallet base so that they can fold down to a collapsed condition or be removed from the pallet and stacked for transport of the container in a folded down condition, are well known in the industry. It is of course desirable for collapsible containers to allow one or more operators to easily and quickly access their interior. When loading an empty container with goods, normally either one or both of the front and rear gates of the container are removed from the pallet base, whilst the remaining pair of side panels remain upright. This allows one or more operators to readily access the container from both the front and rear thereof and facilitaf-e the loading operation (as well as the unloading). It has been found in practice that with the front and rear gates removed or folded down, there is the danger of one or both of the side panels or gates accidentally collapsing inwardly under their own weight (or by means of an inadvertent externally applied force) onto an operator positioned within the interior of the container.

The weight of such panels or gates is quite considerable and even when collapsing under its own weight, considerable injury can be sustained by an operator when struck by the gate or panel.

It is desirable therefore that the side panels or gates of a collapsible storage container remain safely upright during loading or unloading operations, and are constrained against WO 95/30586 PCT/AU95/00257 2 accidental or inadvertent inward collapsing movement under their own weight onto the base of the container.

In our earlier filed Australian Patent Application No 46200/93, there is described an improved pivotal friction mounting which, as the side panel is rotated inwardly, provides a resistive braking force to effectively control the movement of the gate and prevent it from collapsing inwardly under its own weight. The mounting allows the gate to be swung inwardly and retained in a number of angular positions relative to the base. Whilst such an arrangement has generally proved satisfactory in practice, it has been found that where the weight of the actual panel or gate is constructed of heavy duty or robust materials, an operator must exert a significant lifting force in order to lift the swinging panel or gate from its fully collapsed position on the pallet base to its upright condition wherein the panel lies at right angles to the base. In some instances, it has been found that the force required to lift the weight of the panel and also overcome the resistive braking force of the pivotal mountings exceeds acceptable occupational health and safety limits.

It is the main object of the present invention to provide an improved linkage mechanism between the side panel(s) or gate(s) and the base of a collapsible container which will not only effectively control the inward swinging movement of the gate or panel and reduce its likelihood of inadvertently or accidently collapsing onto the base of the container, but also assist the upward lifting movement of the gate or panel when swung to its erect upright position on the base.

It is another object of the present invention to provide an improved linkage mechanism for a swinging panel or gate of a collapsible storage container which is of extremely simple construction, inexpensive, and which is readily replaceable.

WO 95/30586 PCT/AU95/00257 3 Broadly according to this invention therefore, there is provided torsional linkage means for controlling the movement of a pivotally mounted gate or panel of a collapsible storage container, said torsional linkage means comprising an elongate torsion rod or link member which at one end has a first end portion connecting to locating means on said gate or panel adjacent a bottom corner region thereof, and which at its other opposite end has a second end portion connecting to further locating means on said base remote from said bottom corner region of the gate or panel, said torsion rod or link member being operable to resist inward swinging movement of the gate or panel and to function as a flexural and torsional return spring for assisting the upward swinging movement of the gate ox panel to an upright position.

Preferably the torsion rod or link member has a length which is slightly less than the length of the panel measured between the bottom corners thereof.

Preferably the torsion rod or link member, when installed, is preloaded and has its opposite first and second ends bent in opposite directions, with the bent extremities being in offset relationship.

Preferably, the torsion rod or link member is mounted so that, when the panel is upright, the rod lies between the bottom rail or frame member of the panel and the upper edge of a skirting wall forming member which extends along one side of the container base.

Preferably the bent opposite ends of the torsion rod or link member are anchored in cylindrical sockets fitted interiorly of the bottom peripheral frame member of the panel and the skirting wall forming member respectively. Alternatively, one of the bent ends of the rod can be anchored in an externally mounted sleeve or socket on the gate or panel WO 95/30586 PCT/AU95/00257 4 adjacent said bottom corner region thereof, while the other opposite end of the rod is anchored to a sleeve or socket fixed to an upstanding angle stub corner post on the base of the container.

Due to the tendency of the torsional link or rod member to act as a return spring, in some instanzes the swinging gate or panel may 'bounce back" when swung partly inwardly to an inclined position. To counteract the "bcunce back" effect, appropriate friction washers may be mounted on the pivot pins or bolts which pivotally support the swingitig gate or panel and which apply frictional forces to the gate. This then ensures that the gate or panel can, if desired, be swung inwardly and retained, (on its own accord), in a fully or semi-collapsed position.

Normally, each of the side panels of the container will be fitted with a torsional linkage rod. When fully collapsed, the side panels, unless restrained, will tend to both "bounce back" which, of course, is undesirable when the container needs to be transported in a flattened condition. According to another feature of the present invention, co-operable latch and latch engaging means are provided on the two side panels for releasably locking the side panels in fully collapsed overlapping positions on the base against upward swinging movement.

Preferably, the latch comprises a spring loaded latch pin carried on a side frame member (on its inside surface) of the first-to-fold-down side panel, while the latch engaging means comprises a hook member fixedly carried on the inside of the side frame member of the second-to-fold-down panel, the hook being arranged, when the panel is fully collapsed, to project through a slotted opening in the side frame member of the other panel and lockingly engage (automatically) with a tongue on said latch pin. The panels can be unlocked by WO 95/30586 PCTIAU95/00257 simply manually actuating the latch pin so as to release it from the hook following which the "bounce back" effect causes the panels to automatically assume inclined dispositions, still in overlapping relationship. The panels can then be very easily manually lifted upwards to their fully erect positions.

With the linkage mechanism of the present invention, each of the two side panels can be returned to their erect upright positions with minimum effort exerted by the operator. With the side panels in their fully upright position, the normally removable front and rear gates can then be reassembled in position, to complete the assembly of the container in its erect condition.

In order more fully explain the present invention, a preferred embodiment thereof is described hereunder in some further detail with reference to and as illustrated in the accompanying drawings wherein: Fig 1 is a fragmentary exploded perspective view of part of a collapsible storage container showing one of the side panels and the base of the container and the torsional linkage interconnecting same; Fig 2 is a perspective view of a corner region of the container base showing the connection of the torsion rod to the skirting member; Fig 3 is a fragmentary perspective view of the container assembly shown in Fig i, and which shows the swinging side panel in its collapsed condition on the container base while; Fig 4 is a fragmentary sectional view showing the two side panels in their fully collapsed locked position.

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WO 95/30586 PCTIAU95100257 6 According to this embodiment, a collapsible container comprises a pair of pivotal side gates or panels 11, 11' each of which is hingedly connected to the base 12 by a pair of transversely aligned pivot pins or bolts 13 for swinging movement between an upright position wherein the panel 11, 11' extends at right angles to the base 12 and a collapsed condition wherein the panel lies approximately flat on the floor 14 of the base 12. In this embodiment, each of the pivot pins 13 passes through an opening 15 formed in one of the flanges of angle section stub corner posts 16, 17 located at the corners of the base 12. The panels 11, 11' are supported above side skirting wall members 18 which extend along opposite sides of the base 12 and which may be of different heights above the floor 14. This construction is in accordance with known art.

An elongate torsion rod or link member 21 is operatively connected between the swinging panel 11 adjacent one lower corner 22 thereof to a corner region of the base 11 remote from the corner 22. The torsion member 21 has its extremities bent in opposition directions so as to form an upturned spigot portion 23 at one end and a downturned spigot 24 at its other opposite end. In this embodiment, the bent extremities 23, 24 are angularly offset with respect to one another.

The offset spigot portions 23, 24 snugly locate in short length cylindrical sockets or tubes 25, 26 secured respectively, eg by welding, internally of the tubular bottom frame member or rail 27 of the panel 11 and on the outer vertical face of the skirting member 18. In this embodiment the rail 27 is formed of tubular steel having a flattened oval-shaped cross-section, while the skirting member 18 is channel-shaped with its channel opening outwards.

Of course, the ends 23, 24 of the rod 21 could be removably anchored in mountings respectively fitted to the rail 27

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WO 95/30586 PCT/AU95/00257 7 externally thereof and one of the inner flange surfaces of the corner post 16. The socket 26 can form part of a fitting used to secure the skirting member 18 to the angle corner post 16.

In this embodiment, the bent extremities 23, 24 locate through holes formed in the bottom edge of the rail 27 and the upper flange 29 of the skirting member 18, and which align with their corresponding sockets 25, 26.

The torsion rod 21, when mounted in position, extends approximately parallel to the floor 14 of the base 11 and lies between the upper horizontal flange 29 of the skirting member 18 and the bottom edge of the rail 27 of panel 11.

Preferably, with the panel 11 fully upright, the bottom edge thereof is contiguous (or nearly so) with the upper surface of the rod 21.

With this arrangement, the elongate torsion rods 21 are conveniently located along opposite sides of the base 12 and do not intrude into the loading space of the container Due to the influence of the torsion member 21, each of the side panels 11, 11' has a tendency to "spring back" when the panel is swung inwardly to a fully or semi-collapsed position relative to the base 12. In order to inhibit such "spring back" of the panels 11, 11' with the panels fully collapsed on the base 12 in overlapping relationship (refer Fig a spring loaded latch pin or rod 30 fitted to panel 11' at one side thereof lockingly engages with a fixed latching hook 31 carried by panel 11 and which projects inwardly thereof. As the panel 11 swings down on top of folded-down panel 11', the hook 31 passes into and projects through a slot-like opening 33 formed in side rail member 34 of panel 11ii', and in so doing makes camming contact with a locking plate 35 on the pin 30, with the pin 30 and plate being axially displaced against the pressure of spring, 36 ~sll~PID~i~u~ WO 95/30586 PCT/AU95/00257 8 whereafter the plate 35 is lockingly retained within latching recess 37 of hook 31. The plate 35 is released by manually pushing the head end 38 of pin 30 which is readily accessible from the side of the base 12 in the direction of arrow 39.

Each of the side rails 34 of the panels 11, 11' is formed of angle section steel. This is advantageous in that it enables the latching pin assembly 30 to be housed conveniently within the recess formed by the angle member 34.

Each torsion member 21 may be mounted with a degree of flexural and torsional preloading so that it exerts a restoring moment on the panel 11ii, 11' when in its fully upright position.

As shown in Fig. 1, each angle corner post 16, 17 has welded to its upper edge a metal plate 41 which carries a fixed locating spike 42 for engaging a bottom corner of a container base when stacked there-on-top. The bottom edges 43 of the flanges of the angle frame members 34, when the panel 11, 11' is in its erect upright position, are arranged to make contact with and bear against the upper surfaces of the plates 41, whereby any loading forces borne by the side panels 11, 11' will be transmitted downwardly to the base 12 via the corner posts 16, 17, with the pivot pins 13 and skirting members 18 being essentially non-load bearing. This also prevents undesirable loading forces, when the assembled container is in use, being transmitted to the torsion rods 21.

In order to collapse the container 10, the front and rear gates (not shown) are first removed from the front and rear of the assembled container 10, and then placed on the base 12, following which the panels 11, 11' are swung inwardly, one after the other, so that they lie approximately flat on the base 12 (on top of the front and rear gates), in overlapping relationship.

i 9 IfillQIIPIBICbC lu*rrruluu~ew" WO 95/30586 PCT/AU95/00257 9 The latch mechanism 30, 31 is automatically engaged as the panels 11, 11' are brought together in their collapsed positions on the base 12. The container 10 is then ready to be transported or stored away in its collapsed condition.

When it is desired to assemble the container 10, the latch pin 30 is released and the gates or panels 11, 11' are lifted, one after the other, from their collapsed position on top of the base 12, the upward swinging movement of the panels being assisted by the torsion members 21 by virtue of flexural and torsional forces. This has been found in practice to be a considerable advantage to operators where the panels 11, 11' are of heavy duty construction and of considerable weight. The panels or gates 11, 11' can be lifted upwardly to an erect position without excessive physical effort, and, when erect, will not collapse inwardly onto the floor 14 of the base 12 under their own weight, due to the resistance provided by the rods 21. Thus if the panel is accidentally knocked or bumped, it will not collapse fully inwards.

It will of course be realised that the fitting of the torsion members 21 to the side panels and the container base may be carried out in a number of different ways as well as any pretensioning thereof.

The hooks 31 on the side panels 11, 11' primarily serve the function of locating the removable front and rear gates in their upright position on the base 12. Each front and rear gate has a pair of locating pins on opposite sides thereof, each pin slidably engaging in a respective hook 31 during the mounting of the front/rear gate to the base 12. Normally, the front and rear gates are each formed of two halves with each half being hingedly connected to the other so that they can lie flat against one another.

i i i II _II YBUBYQIIDIRlbCYLur~lrrm~rr~ra~l~ WO 95/30586 PCT/AU95/00257 A brief consideration of the abovedescribed embodiment will indicate that the invention provides for an extremely simple and effective torsional linkage mounting for a swinging gate or panel, in particular a side panel of a collapsible storage container, which will not only prevent accidental collapsing of the gate from its upright position, but will also serve to assist the upward lifting movement of the gate and to maintain the gate in an upright condition, without the need for any additional catches or latching devices, when loading or unloading the container.

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Claims (8)

1. 2. A collapsible storage container according to claim 1 wherein said latch comprises a manually operated spring loaded movable latch pin fitted to a first side frame member of one of said side panels, and wherein said latch engaging means comprises a latching hook fixedly carried on a second side frame member of the other of said side panels, said hook being arranged, when the panels are fully collapsed, to project through a slotted opening in said first side frame member and lockingly engage with said latch pin.
2. 3. A collapsible storage container according to claim 1 or claim 2 wherein the first and second end portions of said torsion rod or link member are bent in opposite directions, and are in offset relationship to one another. AMENDED SHEET IPENAU -I ii PCT 9 5 0 0 25 7 SRECEJVEO 1 8 JAN 1996 12
3. 4. A collapsible storage container according to claim 3 wherein said torsion rod or link member has a length which is slightly less than the length of the side panel measured between the bottom corners thereof. A collapsible storage container according to any one of the preceding claims wherein the first and second end portions of the torsion rod or link member are anchored in cylindrical sockets mounted respectively on a bottom frame member of the side panel and a skirting wall forming member which extends along a respective side of the container base.
4. 6. A collapsible storage container according to any one of the preceding claims wherein said torsion rod or link member is mounted so that when said side panel is upright, the rod lies between the bottom frame member of the side panel and the upper edge of said skirting wall forming member.
5. 7. A collapsible storage container according to any )ne of the preceding claims wherein each one of said opposite side panels is provided with a respective said torsion rod or link member.
6. 8. A collapsible storage container according to any one of the preceding claims wherein the bottom frame member of each of the side panels is formed of flattened tubular steel.
7. 9. A collapsible storage container according to claim 8 wherein said further locating means for the second end portion of the torsion rod member is fixedly secured internally of said bottom frame member. A collapsible storage container according to claim 2 wherein the side frame members of the side panels are of angle section; and wherein the latch pin is housed within the recess defined by the angle section of said first side frame member. AMEN-EOD SHEE' IO'ENAU PCT/A 95 0 0 2 5 7 RECEIVED 1 8 JAN 1996 13
8. 11. A collapsible storage container according to claim wherein said latch pin projects beyond the outer or upper end of said first side frame member. AMENDED SHEET IPEA/AU I-