WO2019056073A1

WO2019056073A1 - A bulk bin and bag liner

Info

Publication number: WO2019056073A1
Application number: PCT/AU2018/051043
Authority: WO
Inventors: Gary Hill
Original assignee: Materials Handling Systems Australia Pty Ltd
Priority date: 2017-09-21
Filing date: 2018-09-21
Publication date: 2019-03-28

Abstract

The present invention relates to a knock-down bulk bin and a bag liner for a bulk bin. The bulk bin includes features such as a base-structure that is configured to receive forktines, a collapsible upper assembly that is supported on the base-structure, wherein the upper assembly has a quadrangular frame and four corner posts and the corner posts extend above the quadrangular frame so as to provide a spacing between the base-structure of the upper bulk bin and the quadrangular frame of the lower bulk bin, such that a closure can be accommodated between the base- structure of the upper bulk bin and the quadrangular frame of the lower bulk bin.

Description

A BULK BIN AND BAG LINER

FIELD OF THE PRESENT INVENTION

The present invention relates to a knock-down bulk bin. The present invention also relates to a bag liner for a bulk bin.

BACKGROUND OF THE PRESENT INVENTION

Bulk bins typically have a capacity on the range of 0.5 to 3 cubic metres and can be used for carrying a large range of different materials such as agricultural produce, mining materials and feedstock of manufacturing processes. There are at present a variety of different bulk bins on the market and one type of bulk bin that has gained wide acceptance in a number of different applications, particularly in the food related processing industries is a knock-down bulk bin. A feature of the knock-down bin is that when in an assembled orientation, the bin is used to transport material from a supplier to a consumer, and once the bin has been emptied by the consumer, the bin can be collapsed and transported back to the supplier in a space saving manner for re-assembly and re-filling by the supplier. Knock-down bulk bins are generally of significant monetary value and may or may not include a bag liner that is discarded after each use or on an as needs basis.

Ideally the bag liner may be closed to reduce contamination of the contents of the bag liner.

SUMMARY OF THE INVENTION

An embodiment relates to a knock-down bulk bin including:

a base-structure that is configured to receive forktines of lifting machinery for moving the bulk bin;

a collapsible upper assembly that is supported on the base-structure, wherein the upper assembly has a plurality of collapsible legs, each leg having at least two members that are interconnected in a way that allows relative movement between the members, and in turn allows the upper assembly to be moved between, i) a collapsed orientation to facilitate transportation of the bulk bin in a space saving manner while a bag liner remains attached to the upper assembly, and ii) an erected orientation for supporting the bag liner;

wherein the upper assembly has a quadrangular frame and four corner posts, in which the corner posts have a support surface on which another of the knock- down bulk bins can be seated in a stacked relationship (hereinafter referred as an "upper bulk bin that is stacked on top of a lower bulk bin"), in which the corner posts extend above the quadrangular frame so as to provide a spacing between the base- structure of the upper bulk bin and the quadrangular frame of the lower bulk bin, such that a closure can be accommodated between the base-structure of the upper bulk bin and the quadrangular frame of the lower bulk bin.

The bulk bin may also include a bag liner attached to the upper assembly with an entrance of the bag liner in an upwardly facing orientation for filling. It is possible that material may be emptied from the bulk bag via the entrance by tilting or tipping the bulk bin on to one side.

The closure may include a flexible panel and a first interlocking formation that cooperate with second interlocking formations for securing at least parts of the perimeter of the flexible panel to the bag liner in a closed position.

The interlocking formations may include press fit devices such as clasps, hook and loop fasteners, press fitting buttons, clasp lockers and so forth. The interlocking formations may include a zipper. Ideally, the interlocking formations are operable for securing a perimeter about the flap.

The closure may include a rigid lid that can be pivotally connected to the

quadrangular frame and closes to shut an opening of the bag liner. The rigid lid may be a single lid pivotally mounted to the upper assembly. The single lid is ideally sufficiently rigid so that it can span self-supportingly across the opening of the bag when closed over the opening of the bag. Ideally, the rigid lid may be a pair of lids pivotally mounted to the upper assembly that are moveable to open and close the entrance to the bag, and the lids have a stiffness that allows the lids to be seated against the upper assembly when closed and span self-supportingly over the entrance of the bag.

In an embodiment, the corner posts may be sized to accommodate the closure in the form of either one of the flexible panel or the rigid lid. The corner posts provide a spacing between the support surface of a lower bulk bin and the base-structure of the upper bulk bin to allow the bulk bins having any suitable closure to be stacked one on top of the other. By allowing an appreciable spacing, the closure can be changed between the flexible panel and the rigid lid, or vice versa, as required.

Moreover, a bulk bin having a flexible closure can be stacked on top of a bulk bin having a rigid closure, and vice versa. In one embodiment, the bag liner may be changed as the closure is changed between the flexible panel and the rigid panels.

Ideally, the corner posts extend by a length ranging from 10 to 100mm above the quadrangular frame. Even more suitably, the corner posts extend by a length 10 to 60mm and even more suitably from 10 to 40mm above the quadrangular frame, and even suitably by an amount ranging from 25 to 35 mm, and even more suitably approximately 30mm above the quadrangular frame. In other words, a lower surface of an upper bulk bin is spaced from an upper surface of the quadrangular frame of the lower bin.

The corner posts may have an upper corner post section that extends above the upper surface of the quadrangular frame. In one embodiment, the length by which the corner posts extend above the upper surface may be fixed, that is, non- adjustable. In another embodiment, the length by which the corner posts extend above the upper surface may be adjustable. For example, the upper corner post section may be telescopic. In another embodiment, the point at which the quadrangular frame attaches to the corner posts may be adjustable. The attachment may be provided by a fastener, including nut and bolt, or a self-taping screw. The spacing between the base-structure of the upper bulk bin and the quadrangular frame of the lower bulk bin may be the length between the support surface and the quadrangular frame of each bulk bin.

The support surface may include a flat planar surface and a spigot that extends above the flat planar surface. Ideally, the length between the flat planar surface and an upper face of the quadrangular frame ranges from 10 to 100mm. Even more suitably, the corner posts extend by a length of 10 to 60mm and even more suitably from 10 to 40mm above the quadrangular frame.

The bag liner may have a base panel and a side wall extending from the base panel. The side wall may have reinforcing straps that extend diagonally across the side wall. Ideally, the side wall has four adjacent side panels, and two reinforcing straps extend diagonally on each side panel that crisscross at a point intermediate of the side panels.

The reinforcing straps of adjacent side panels may also extend from one side panel to another and cross at a junction between adjacent side panels.

The bag liner may have a lip or top panel about a perimeter of the bag liner to which a co-operating interlocking formation, such as zipper, for connection to the flexible panel closure is provided. The lip may provide an overhang between the lip and the side wall of the bag liner. The overhang may form a cavity. The term "lip" and the term "top panel" are used interchangeably throughout this specification.

The bag liner may have an infill panel that extends over the cavity, thereby reducing the likelihood of material remaining in the bag liner during emptying. Ideally, the infill panel forms a barrier which closes the overhang.

The cavity may extend about an upper perimeter of an opening of the bag liner. The infill panel may be arranged to span between adjacent side panels of the side wall, and the lip or top panel. In one embodiment, the infill panel extends around the perimeter of the entrance of the bag liner. In another embodiment, the infill panel extends about part of the perimeter of the entrance.

The infill panel may be any suitable shape. By way of example, the infill panel may have any suitable geometric shape including, square, rectangular, an elongated strip, or triangular. The infill panel having a triangular shape is particularly suitable for closing the cavity between adjacent side panels of the side wall and the lip, i.e., the infill panel located in a corner of the side wall. Ideally, the infill panels are located at the overhang of two corners of the bulk-bag, namely in two adjacent corners of the bulk bag. This can help prevent material from being caught in the bulk-bag during emptying of the bulk bag. The bag liner may be made of any suitable material including polymeric sheets, woven fabrics, and fabric that is suitable for use in refrigeration. Ideally the bag liner is made of woven polypropylene.

The upper assembly may also include a support plate for supporting the side wall of the bulk bin when the bulk bin is tilted for emptying via the entrance, thereby further minimising the opportunity for material to become caught in the bag liner during emptying. The support plate may extend from the quadrangular frame and be located on the outside of the bag liner. Infill panels may be arranged at the corners of the bag liner that are adjacent to the support plate.

The support plate may be arranged so as not to extend outside of the collapsible legs of the bulk bin.

The support plate extends downwardly from the upper assembly and extends over at least half the width of the upper assembly.

The support surfaces of the corner posts may include a spigot that is arranged to be received by an opening of the upper bulk bin when stack one on top of the other. The support surfaces may include a flat planar surface and a spigot that extends above the flat planar surface. The spigot may have a convex or parabolic upward facing surface which helps guide the upper bulk bin into position when the bulk bins are stacked on top of the other. The main benefit we have found is that a user stacking one bulk bin on top of the other can lower and tilt the upper bulk bin so that the two spigots closest to the user, and which are visible, are received in the openings of the upper bulk bin. This provides assurance that the upper bin is aligned in the correct position. The user can then tilt the bulk bin away from themselves into an upright orientation so that the rear spigots are received by rear openings of the upper bulk bin. Once the two closest spigots are received, the user can tilt the bulk bin knowing that the rear spigots will align with and be received by the rear openings.

The side wall of the bag liner may include a lower discharge door that can be opened and closed. The lower discharge door may include a flap having first interlocking formations that co-operate with second interlocking formations one the side wall for closing the flap to the side wall. The first and second interlocking formation may include press fit devices such as clasps, hook and loop fasteners, press fitting buttons, clasp lockers, and a zipper about the perimeter of the door. The first and second interlocking are arranged to allow the flap to be opened and closed by a user outside the bag liner. The flap of the lower discharge opening may form part of the side wall when closed. The flap is pivotally connected to the side wall of the bag liner and includes gusset panels on opposite sides of the flap that extend between the side wall of the bag liner and the flap. When the lower discharge door is in an opened position, the gusset panels may provide a guiding formation for guiding material from the bulk bag. Ideally, the gusset panels extend at least half the height of the lower discharge opening.

The gusset panels may be held taught when the flap is in an opened position. When the lower discharge door is in a closed position, the gusset panels are located inside the bulk liner. The lower door may be made of any suitable material including fabric material, and suitably, the same material as the side wall of the bag liner.

In one example, the lower door may be sized to extend only part way across the width of the side wall. For instance, the door may extend up to 10%, 20%, 30%, 40% or 50% across the width of the side wall. In this example, the lower door is ideally centrally located on the side wall.

In another example, the lower door may extend across at least half the width of the side wall, and optionally substantially across the entire width of the side wall.

The collapsible legs may have a locking mechanism that can be operated to lock the legs in the erected position.

The collapsible legs may have an upper section and a lower section that are pivotally connected, and the upper and lower sections align coaxially and overlap when in the erected position.

Suitably, the upper and lower sections are pivotally connected by a pin extending through openings in the upper and lower sections and the openings include a slot in at least one of the upper and lower sections which allows the pin to move along the slot(s) and thereby allow the pivot connection to move, which in turn allows coaxial movement of the upper and lower sections relative to each other.

The locking mechanism may include a locking lug extending from one of the upper and lower sections, and a recess in the other of the upper and lower sections that receives the locking lug when the upper and lower sections are in the erected position, thereby preventing pivotal movement between the upper and lower sections. The locking lug may be received by the recess when the upper and lower sections are located in the erected position and the upper and lower sections are coaxially retracted with the pin in a first position in the slot.

The locking mechanism may include a latch that is operable to lock the pin in the first position in the slot, thereby preventing the upper and lower sections from moving from the coaxially retracted position to an extended position, in which the locking lug can be removed from the recess.

The latch may extend from the pin, and the pin may be biased so as to hold the arm in the slot, thereby preventing the upper and lower sections from moving from the coaxially retracted position. A user can manually push the pin and remove the latch from the slot, thereby allowing the upper and lower sections to be moved coaxially and release the locking lug from the recess.

Another embodiment relates to a knock-down bulk bin including:

a base-structure that is configured to receive forktines of lifting machinery for moving the assembly;

a collapsible upper assembly that is supported on the base-structure, wherein the upper assembly has a plurality of collapsible legs, each leg having at least two members that are interconnected in a way that allows relative movement between the members, and in turn allows the upper assembly to be moved between, i) a collapsed orientation to facilitate transportation of the bulk bin in a space saving manner while the bag remains attached to the upper assembly, and ii) an erected orientation for supporting a bag liner;

the collapsible legs have the upper and lower sections that are pivotally connected by a pin extending through openings in the upper and lower section and the pin is received within openings extending through the upper and lower section, in which and the openings include a slot in at least one of the upper and lower sections to allows the pin to move along the slot(s) and thereby allow the pivot connection to move, which in turn allows coaxial movement of the upper and lower sections relative to each other and the collapsible legs have a locking mechanism that can be operated to lock the legs in the erected position in which the locking mechanism includes:

a locking lug extending from one of the sections and is received by the recess when the upper and lower sections are located in the erected position and the upper and lower sections are coaxially retracted coaxially with the pin in a first position in the slot, and a latch that is operable to lock the pin in the first position in the slot, thereby preventing the upper and lower sections from moving from the coaxially retracted position to an extended position, in which the locking lug can be removed from the recess.

Another embodiment relates to a bag liner for a knock-down bulk bin having a base- structure that is configured to receive fork tines of lifting machinery, a collapsible upper assembly that is supported on the base-structure, the upper assembly has a quadrangular frame and four corner posts that extend upwardly from the

quadrangular frame, wherein the bag liner includes: a base panel having four sides; a side wall having four side panels that extend from the base panel; a lip formation extending inwardly of the side wall so as to define an opening to the bag, and the lip formation having a fastener, such as a zipper, for attaching to a lid panel having a co-operating zipper; and an infill panel that extends from the lip formation adjacent to the opening to the side wall so as to form a barrier to an overhang under the lip formation. By barricading the overhang with the infill panel, we have found that the likelihood of the contents becoming caught in the lip formation during emptying is reduced. The infill panel may be arranged over the intersection of two side wall panels.

Specifically, the infill panel may be arranged inwardly of an upper corner of the bag liner. The infill panel may also be arranged to extend between the lip formation and the side wall over one or more of the side panels.

The bag liner may also include any one or a combination of the other features of the bag liner described herein including the following.

i) One or more diagonally arranged reinforcing straps for reducing the side bulge from the bag liner when loaded.

ii) One or more lower discharge door with a zipper about a perimeter of the door. The discharge door is pivotally connected to the side wall of the bulk bin and includes gusset panels on opposite sides of the lower door that extend between the side wall of the bulk bin and the door. BREIF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings, of which:

Figure 1 is a schematic illustration of a bulk bin including a base structure, a collapsible upper assembly supported on the base structure, the collapsible upper assembly including collapsible legs that are illustrated in an erected orientation, and a bag liner having a closure in the form of a fabric panel having a zipper about the opening of the bulk bag, in which the bulk bin is located in an erect orientation; Figure 2 is a cross-sectional view through the lines A-A in figure 1 ;

Figure 3 is a schematic illustration of a quadrangular frame of the upper assembly having a pair of rigid lids for closing the opening of the bag liner; Figure 4 is a schematic illustration of the bulk bin shown in figure 1 , in which the bulk bin is located in a collapsed orientation; Figure 5 is a schematic illustration showing in inside view of a bag liner having reinforcing straps in a criss-cross formation;

Figure 6 is a schematic illustration showing a side wall of the bulk bag having a lower discharge door with gussets that assist in guiding material through the discharge door;

Figure 7 is a schematic illustration showing a close-up view of an infill panel for barricading or closing an overhang between a lip formation and adjacent panels of a side wall of the bag liner;

Figure 8 is a schematic illustration of the collapsible legs of the bulk bin shown in figure 1 in a collapsed orientation; and Figures 9 and 10 are close-up views of a locking feature for securing the collapsible legs shown in Figure 1 and 7 in an erected orientation.

DETAILED DESCRIPTION

A preferred embodiment will now be described in the following text which includes reference numerals to help identify the features in the accompanying figures.

However, in order to maintain the clarity of the figures, not all of the reference numerals are included in each figure.

The preferred embodiment relates to a knockdown bulk bin 10 including a base- structure 1 1 that is configured to receive fork tines of lifting machinery such as a forklift, and a collapsible upper assembly 12 that is supported on the base-structure 11 , and a bag liner 21 suspended to the upper assembly 12.

The base-structure 1 1 has a subframe comprising four lower corner posts 13 and four lengths of steel strip 15 that are arranged between the lower corner posts 13 which engages the ground when the bulk bin 10 is seated on the ground, and an upper deck comprising four tubular sections 15 arranged between the lower corner posts 13 at a spacing from the steel strip 14, and a plate arranged to form a continuous surface between the lower corner posts 13. Additional support posts 16 are also located intermediate between the corner posts 13 and interconnect the steel strip 14 and the tubular sections 15. The base-structure 1 1 comprises openings either side of the support posts 16 for receiving fork tines of a forklift. The openings may be provided on all sides of the bulk bin 10.

The upper assembly 12 includes a quadrangular frame 29 having four peripheral members 17 about the frame and four upper corner posts 18. The corner posts include upper corner posts sections 18. The upper corner posts 18 each have an upper support surface 19 that includes flat planar surface and a parabolic dome shaped spigot 20 that extends upward from the flat planar surface 19. As can be seen, the spigot has a symmetrical shape and is centrally located on the flat planar surface. When the bulk bins are stacked, the spigot 20 can be received within downwardly facing openings of each of the lower corner posts 13 of the base-structure 1 1.

As can be seen in figures 1 and 3, the corner posts include the upper corner posts 18 that extend above the quadrangular frame so that the support surface 19 of the upper corner posts 18 is clear of the quadrangular frame, which in turn, enables various closures to be fitted to the bulk bin for closing the bag liner 21. For example, figure 1 illustrates an embodiment in which a closure in the form of a fabric lid having a zip fastener is used to close the opening of the bag liner 21.

Figure 3 illustrates an embodiment in which the closure includes a pair of rigid lids 22 that are pivotally connected to the quadrangular frame 29. The height of the upper corner posts 18 above the quadrangular frame 29 enables a variety of different closures to be substituted as required.

Figure 2 is a schematic cross-sectional view through the arrows A-A in figure 1 , and includes a peripheral member 17 of the quadrangular frame, a top section 23 of a side wall 28 of the bag liner 21 that forms an inwardly extending lip formation that defines the opening of the bag liner 21 and which has a co-operating zipper 24 for the fabric lid 29, and an outwardly extending flap that extends over the peripheral member 17. An L-shaped section 26 is placed over the peripheral member 17 and tasters 27, such as self-tapping screws can be fitted through the L-shaped member 26 to secure the bag liner 21 in an operative position. The bag liner 21 includes a base panel 30 having four sides, a side wall 28 having four side panels 34, in which each side panel 34 extends from the sides of base panel 30 such that the bag liner 21 has a cube or a rectangular shape. As described above, the bag liner 21 may include a lip formation 23, particularly when the closure for the bag liner is a fabric lid 29 having a co-operating zipper 24. However, it will be appreciated that rigid lids 22 may also be used for closing the opening of the bag liner 21 even when the zipper 24 is present. In another embodiment, the lip formation 23 and a zipper 24 about the opening of the bag liner 21 may be omitted when the opening of the bag liner 21 is closed using a rigid lid 22. Figure 4 illustrates the bulk bin 10 in a collapsed orientation with the bag liner 21 attached, and the closure includes a pair of rigid lids 22 that are pivotally attached to opposite side of the quadrangular frame 29. The rigid lids overlap in the middle when closed. As can be seen, the upper corner sections 18 extend above the quadrangular frame, thereby allowing the bul bins to be stacked, when the collapsed orientation. The height or length of the corner posts above the lid 22, enables alike bulk bins to be stacked in which the base structure 11 of the upper bulk bin can avoid contacting the closure of the lower bulk bin.

With reference to figure 5, the bag liner 21 includes reinforcing straps 30 arranged diagonally over the height of the side wall 28 of the bag liner 21 to minimise the amount of sideways bulging of the side wall 28 of when loaded with material. Ideally, the reinforcing straps 32 can prevent the side wall 28 of the bag liner 21 from bulging outside of the legs of the bulk bin 10. Ideally the reinforcing straps 32 are arranged in a criss-cross formation in which a lower end of the reinforcing straps 32 is attached to a lower corner of the side panels 34 and extend upwardly toward an opposite upper corner of the side wall 28 such that the reinforcing straps 32 cross at a midpoint 38 or intermediate of the side panels 34. In addition, the reinforcing straps 32 extend toward the upper corners and onto the adjacent side panel toward the opening of the bag liner 21. As a result, the reinforcing straps 32 extending from adjacent side panels 34 and cross at point 39 that is located at, or near, a corner of the bag liner 21 , and preferably below an opening of the side wall 28 of the bag liner 21. The corner of the bag liner 21 is suitably located adjacent to the erected posts.

As can best be seen in figures 2 and 7, the bag liner 21 also includes an infill panel 25 that extends between the lip formation 23 or top panel, and the side wall 28 of the bag liner 21. The infill panel 25 closes an overhang formed by the lip formation 23 and reduces the likelihood of material in the bag liner 21 from being caught on the lip formation 23 when the contents of the bag liner 21 are emptied. The infill panel 25 may have any desired shape including: i) an elongate shape that is aligned to extend along the width of one of the side panels; ii) a triangular shape for interconnecting the lip formation and adjacent side panels 34.

An example of a triangular infill panel 25 is provided in figure 7. The infill panel 25 may also extend completely, or only partially, about the opening of the bag liner 21. In any event, the infill panel 25 can provide a continuous wall formation from the side panel 34 to the opening or entrance of the bag liner 21.

Figure 6 illustrates a lower openable door 35 in a side panel 28 of the bag liner 21. The openable door 35 having a quadrangular shaped flap, of which a lower side of the openable door 35 is connected to the junction between the side panel 28 and the base panel 30 of the bag liner 21 and a zip fastener that extends about the perimeter of the discharge door 35 and is operable to secure the perimeter of the door to the side panel 28 of the side wall 21. Gusset panels 36 interconnect the side panel 34 of the side wall 28 and the door. The gusset panels 36 may be of any dimension and preferably extend over the height of the door and at least half of the height of the opening in the side panel, and preferably over at least two thirds of the height of the opening and the side panel 28. The gusset panels 36 assist in directing the flow of material discharging through the opening when the door 35 has been opened. One mode of emptying the bulk bin 10 includes the bulk bin 10 being tilted at an angle to one side, for example, such that the opening of the bag liner 21 at least partially faces downwardly. The supporting plate 37 supports the bag liner 21 adjacent to the opening of the bag liner 21 and, if present, the infill panel 25, such that the bag liner 21 can form a slide for material to be dispensed from the bag liner. One of the support plates 37 can be provided on each side of the bulk bin 10, and ideally, on each side of the bulk bin 10 in a direction which the bulk bin 10 is intended to be tilted during emptying. For example, the bulk bin may include two support plates 37, one of each been provided on opposite sides of the bulk bin 10.

Figures 8 to 10 illustrate one of the collapsible legs 40 of the preferred embodiment shown in figure 1 detached from the bulk bin 10 in two positions. When attach to the bulk bin, opposite ends of the collapsible legs 40 can be pivotally connected to the lower posts 13 of the base-structure 1 1 and the upper posts 18 of the rectangular frame using any suitable pin, including nut and bolt fasteners. The collapsible legs 40 can be located in two or more positions, including a collapsed position as shown in figure 8 and an erected position as shown in figures 9 and 10. When in the erected position a locking mechanism of the collapsible legs is operable to maintain the legs in the erected position until the locking mechanism has been released, suitably manually released allowing the collapsible legs to move into the collapsed position under gravity.

The legs 40 have two C-sections of different dimensions so that an inner section 41 fits within an outer section 42. The C-section of the outer section 42 may be attached to the posts 18 of the upper rectangular frame.

The inner and outer sections 41 and 42 may include a pivot point provided by a pin 43 that extends through openings of the inner and outer sections 41 and 42. The pin 43 extends through the openings formed in opposite walls of both of the C-sections. The openings include a pair of holes in the inner section 41 , and a pair of slots formed in the outer section 42 that align over the holes of the inner section 41.

However, it would be appreciated that the inner section 41 may include a pair of slots and the outer section 42 may include a pair of holes. In any event, the slots allow relative movement of the pivot point along the slot. For example, when the legs are located in the erected position, the inner and outer section can move coaxially by the pin moving along the slot.

The locking mechanism includes a peg 44 extending laterally from the inner section 41 , which is best seen in figure 9, that can be located in a cutout 45 at the end of the outer section when the inner and outer sections 41 and 42 are aligned in an erected configuration. The peg 44 been received within the cutout 45 when the inner and outer sections 41 and 42 are coaxially retracted, thereby preventing pivoting movement of the inner and outer sections 41 and 42 relative to each other.

The locking mechanism also includes a latch 46 that extends from the inner section 41 and is biased toward the inner section so that it can be received within the slot 48 of the outer section 42. When the peg 44 of the inner section is received within the cutout 45 of the outer leg 42, the latch 46 is arranged to engage one end of the slot 48, away from the peg 44, which prevents the peg 44 from inadvertently moving out of the cutout 45 of the outer leg while the latch 46 is received within the slot 48. As can be seen, the latch 46 forms part of the pin 43 on which the inner and outer sections 41 and 42 legs are pivotally connected and the latch 46 is provided by an arm extending from one end of the pin 43. A second end of the pin 43 includes a handle 45 and a helical biasing spring located about the pin 43 between the handle 45 and the outer section 42. The biasing spring is operable to move the latch 46 into the slot 48 of the outer section 42 when aligned, thereby preventing the pivot point and in turn the inner and outer sections 41 and 42 moving in an axial direction whilst the latch 46 is located within the slot 48. In order to release the locking mechanism, a user can press the handle 45, moving the latch 48 arm out of the slot 48 and pivoting away from the slot 48. Once the latch 48 has moved out of the slot 48, the inner and outer sections 41 and 42 can be moved coaxially relative to each other to disengage the peg 44 from the cutout 45 by lifting the upper frame. The inner and outer sections 41 and 42 can then be pivoted relative about pin 43 to collapse the legs 40. When the peg 44 is located in the cutout 45, the outer section 42 is prevented from pivoting relative to the inner section 41.

Those skilled in the art of the present invention will appreciate that many variations may be made to the preferred embodiment described herein without departing from the spirit and scope of the present invention.

Claims

1. A knock-down bulk bin including:

wherein the upper assembly has a quadrangular frame and four corner posts, in which the corner posts have a support surface on which another of the knockdown bulk bins can be seated in a stacked relationship (hereinafter referred as an "upper bulk bin that is stacked on top of a lower bulk bin"), in which the corner posts extend above the quadrangular frame so as to provide a spacing between the base- structure of the upper bulk bin and the quadrangular frame of the lower bulk bin, such that a closure can be accommodated between the base-structure of the upper bulk bin and the quadrangular frame of the lower bulk bin.

2. The knock-down bulk bin according to claim 1 , wherein the support surface includes a flat planar surface and a spigot that extends above the flat planar surface.

3. The knock-down bulk bin according to claim 2, wherein the flat planar surface of the corner posts extend by an amount ranging from 10 to 100mm above the quadrangular frame.

4. The knock-down bulk bin according to claim 1 , wherein the spigot has a convex upward facing surface that increases in cross-section in a direction toward the quadrangular frame, and the upper bulk bin has an opening that receives the spigots which can guide the upper bulk bin into position when the bulk bins are stacked on top of the other.

5. The knock-down bulk bin according to claim 1 , wherein the knock-down bulk bin includes a bag liner attached to the upper assembly with an entrance of the bag liner in an upwardly facing orientation for filling.

6. The knock-down bulk bin according to claim 5, wherein the closure includes a flexible panel and interlocking formations that are operable for securing at least parts of the perimeter of the flexible panel in a closed position.

7. The knock-down bulk bin according to claim 5, wherein the closure includes at least one rigid lid.

8. The knock-down bulk bin according to any one of claims 5 to 7, wherein the bag liner has a base panel, a side wall extending from the base panel having four adjacent side panels, and at least two reinforcing straps that extend diagonally on each side panel that crisscross at a point intermediate of the side panels.

9. The knock-down bulk bin according to any one of claims 5 to 8, wherein the bag liner has a lip extending inwardly about the entrance of the bag liner that provides an overhang between the lip and the side wall of the bag liner, and an infill panel that extends across the overhang to form a closed cavity that obstructs access to at least part of the overhang.

10. The knock-down bulk bin according to any one of claims 5 to 9, wherein the infill panel is arranged to span between adjacent side panels of the side wall and the lip panel.

11. The knock-down bulk bin according to any one of claims 1 to 10, wherein the side wall of the bag liner includes a lower discharge door that can be opened and closed, the lower discharge door including flap having first interlocking formations that co-operate with second interlocking formations on the side wall for closing the flap to the side wall, and the lower discharge door includes gusset panels on opposite sides of the flap that extend between the side wall of the bag liner and the flap.

12. The knock-down bulk bin according to any one of claims 1 to 11 , wherein the upper assembly includes a support plate extending downwardly from the

quadrangular frame that supporting the side wall of the bulk bin at a side of the bulk bin to which the bin is tilted during emptying.

13. The knock-down bulk bin according to claim 12, wherein the support plate is arranged on the outside of the bag liner.

14. The knock-down bulk bin according to any one of claims 1 to 13, wherein the collapsible legs have an upper section and a lower section that are pivotally connected, and the upper and lower sections align coaxially and overlap when in the erected position, and the upper and lower sections are pivotally connected by a pin extending through openings in the upper and lower sections and the openings include a slot in at least one of the upper and lower sections which allows the pin to move along the slot(s) and thereby allow the pivot connection to move, which in turn allows coaxial movement of the upper and lower sections relative to each other, and the collapsible legs have a locking mechanism that can be operated to lock the legs in the erected position, and the locking mechanism includes a locking lug extending from one of the upper and lower sections, and a recess in the other of the upper and lower sections that receives the locking lug when the upper and lower sections are in the erected position, thereby preventing pivotal movement between the upper and lower sections, and the locking lug is received by the recess when the upper and lower sections are located in the erected position and the upper and lower sections are coaxially retracted with the pin in a first position in the slot, and the locking mechanism includes a latch that is operable to lock the pin in the first position in the slot, thereby preventing the upper and lower sections from moving from the coaxially retracted position to an extended position, in which the locking lug can be removed from the recess, and a user can manually push the pin and remove the latch from the slot, thereby allowing the upper and lower sections to be moved coaxially and release the locking lug from the recess.

15. A bag liner for a knock-down bulk bin having a base-structure that is configured to receive fork tines of lifting machinery, a collapsible upper assembly that is supported on the base-structure, the upper assembly has a quadrangular frame and four corner posts that extend upwardly from the quadrangular frame, wherein the bag liner includes:

a base panel having four sides; a side wall having four side panels that extend from the base panel; a lip formation extending inwardly of the side wall and defines an opening to the bag, and the lip formation having co-operating interlocking formations for closing a lid panel; and an infill panel that extends across the overhang to form a closed cavity that obstructs access to at least part of the overhang.

16. The bag liner according to claim 15, wherein the infill panel is arranged to span between adjacent side panels of the side wall and the lip panel.

17. The bag liner according to claim 15 or 16, wherein the side wall of the bag liner includes a lower discharge door that can be opened and closed, the lower discharge door having a flap and first interlocking formations about a perimeter of the flap that co-operate with second interlocking formation on the side wall for closing the flap, and the lower discharge door includes gusset panels on opposite sides of the flap that extend between the side wall of the bag liner and the flap.

18. The bag liner according to any one claims 15 to 17, wherein the bag liner has a base panel, a side wall extending from the base panel having four adjacent side panels, and at least two reinforcing straps that extend diagonally on each side panel that crisscross at a point intermediate of the side panels.

19. The bag liner according to any one of claims 15 to 18, wherein the reinforcing straps extend from one side panel to another and cross at a junction between two of the adjacent side panels.

20. A knock-down bulk bin including: