METALLIC BIN WITH RETURNS ON PANELS AND CORNER POSTS

FIELD OF THE INVENTION

This invention relates to a bin and especially a bin fabricated from metal usually steel.

The transportation of powders, liquids and pastes in bins is an on-going problem. The fluid dynamics of liquids and pastes coupled with the fact that some pastes have a specific gravity of as much as 1.2 means that severe demands are placed on the physical characteristics of the bin. Many bins currently in use for the transportation of pastes, powders and liquids comprise rectangular wooden structures that are lined by a watertight liner. It has been discovered that the enormous pressures that are placed on the sides of these bins cause the nails or other fasteners used in the wooden structures to pop out, often resulting in a need to provide external bracing to prevent bulging at the sides of the bin. Wooden bins also suffer from rodent damage due to mice gnawing their way through the wooden sides and into the liner and contents. Although plastics are used for such bins, these bins tend not to have the inherent strength to prevent side wall bulging. Consequently, plastics bins have a limited life span and also tend to be very expensive. Metal bins are used in the transport industry for the transportation of small componentry, aggregate material, powders and in certain cases liquids and pastes. Such bins usually comprise a sturdy metal framework with thin panels secured across the framework to enclose the bin. A weakness of such bins is the tendency of the sides and the base to bow outwardly when the bin is heavily laden. To reduce the likelihood of outward bowing it is often necessary to reinforce the sides and base with strengthening ribs or strengthening braces or alternatively, make the sides and base of thicker cross- section to resist the stresses that cause bowing. Thus

such bins tend to be very heavy.

OBJECT OF THE INVENTION

It is the aim of this invention to provide a bin that is of simple construction, uses comparatively lightweight metal sections and resists bowing without the necessity for the use of thick material or reinforcement.

SUMMARY OF THE INVENTION

According to the present invention there is provided a bin fabricated from metal comprising a frame of corner posts secured to a base, side panels interconnecting the corner posts and base characterised in that the side panels are attached to the corner posts so that the side panels are in tension.

Preferably, the top of the bin is reinforced by an open frame defining an open top.

In one embodiment the base comprises a planar panel with upstanding peripheral flanges, the flanges including returns. In another embodiment the base comprises a tray to which a panel is secured, the tray having returns on its upper edges.

The corner posts are preferably provided with returns on each side and the sides of the panels are also formed with similar returns so that the panels can be intercoupled with the corner posts. In a preferred embodiment the returns on the sides of the panel taper, so that as the panel is slid into interlinked engagement with the corner posts, the tapering of the returns on the side panels places the panels in tension.

Preferably the bin is fabricated in galvanised steel and the components are secured together by the use of spot welds.

DESCRIPTION OF THE DRAWINGS

Embodiments to the present invention will now be described by way of example only with reference to the accompanying drawing in which: Figure 1 is a perspective view of an assembled bin in accordance with one embodiment of the invention.

Figure 2 is a partially exploded perspective view of the components of the bin,

Figure 3 is a side elevational view showing the inter-fitting of components of the bin,

Figure 4 is a sectional view taken along lines 4- 4 of Figure 3,

Figure 5 is a perspective view of a bin in accordance with another embodiment of the invention, and Figure 6 is a perspective view of the bin of

Figure 5 with one corner removed to illustrate the interfitting of the components.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The open topped bin 10 that is shown in Figures 1 to 4 of the accompanying drawings is fabricated from galvanised steel components and is used for the transportation of small articles, particulate material and powders. It is also understood that the bin 10 may be lined with an aseptic plastics liner to enable the bin to be used for the transportation of liquids, powders and pastes.

The bin 10 essentially comprises a framework that is made up of four corner posts 11, 12, 13, 14 and a base tray 20. The sides 21, 22, 23, 24 of the bin are defined by sheets of steel that are secured between the corner posts 11-14 and to the base tray 20. The corner posts, side panels and base tray are all provided with returns defined by folded back lips on peripheral edges. The returns 15 on the corner posts 11-14 engage with similarly profiled returns 25 on the edges of the side panels 21-24. The interlinking of the returns causes the side panels to

be placed in tension when they are secured to the corner posts. Spot welds or occasionally, seam welds are used to secure the components together. The top of the bin is bordered by a top roll 40 which comprises four elongate roll sections 41, 42, 43, 44 joined at the corners by right angle corner bars 45. Each roll 41-44 section has a downwardly extending skirt 46 that overlaps the adjacent side panel and the butting contact between the surfaces of the side panel and the overlapping skirt allows joining of the two components through the use of suitably placed spot welds. A foot 50 is secured to each corner of the base of the bin to define downwardly projecting feet 51-54 that have the effect of raising the base of the bin off the ground. Thus, the bin can be transported by use of fork lifts or other such trolleys.

As shown in Figure 2 the base tray 20 comprises four pieces of angle 31, 32, 33, 34 spot welded in a rectangle around a flat plate 36. The tops of the angle 31, 32, 33 and 34 are provided with a folded lip or return 35.

The corner posts and side panel are illustrated in detail in Figures 2 and 4. As shown in Figures 2, each corner post 11, 12, 13, 14 comprises elongate side flanges 16, 17 that are mutually perpendicular. The side flanges 16, 17 are joined by an inclined joining portion 18 to ensure that the corners do not define a sharp point at the corner. The peripheral edge of each side portion has a return lip 15 formed by folding back the steel sheet as shown in Figure 4. Each side panel 21, 22, 23, or 24 is substantially rectangular with lateral sides 26 and 27, a base 28 and top 29. The sides 26, 27 and base 20 of the panel are all provided with folded back lips that act as returns 25. The returns 25 on the opposed sides 26, 27 of the side panel are tapered so that they diverge towards the base 28 of the panel. The small degree of taper (40mm per metre) ensures that as the side panels are slid into

position between adjacent corner posts the tapering of the return on the side panels places the panels in tension.

To assemble the bin 10 the corner posts, 11, 12, 13, 14 are first secured to the bottom tray 20 through the use of spot welds securing the posts to the tray. The corner posts, 11, 12, 13, 14 extend below the level of the base tray 20. Each foot 50 has lateral edges 51 and 52 with returns 55 that clip into the returns 15 on the adjacent post 11. Each foot 50 is also spot welded to the base tray 20. The corner posts 11, 12, 13, 14 are arranged so that there is a 40mm outward taper per meter.

The side panels 21, 22, 23, 24 are then slid in interlocking engagement into the returns on the corner posts 11, 12, 13, 14 from the base of the bin as shown in Figure 2. The tapered edges of the side panels place the side panels in tension and they are pushed upwards until the return on the base 29 engages return on the base tray 20. The top roll 40 is then slid over the posts 11, 12, 13, 14 and the sides 21, 22, 23, 24 so that the assembly assumes the configuration shown in Figure 2 with the top of the side panels extending between the downward skirt 46 and the interior of the roll. A series of spot welds are then used to weld the top roll to both the corner posts 11, 12, 13, 14 and side panels 21, 22, 23, 24. In the embodiment shown in Figures 5 and 6, the bin 100 includes a slightly different open top and foot structure than the bin described in the earlier embodiment shown in Figures 1 to 4. In this embodiment, the open top is defined by a frame formed of four lengths 102, 103, 104 and 105 of square steel tubing cut at 45° at each end so that they can abut to form a closed rectangular or square. The upper edges of the side panels 21, 22, 23, 24 and corner posts 11, 12, 13, 14 are provided with outwardly laterally projecting flanges 125 under which the rectangular frame is positioned. A top roll in the form of four flanged sections 131, 132, 133, 134 having similarly profiled laterally extending flanges 135 are positioned

under the frame on the exterior of the bin and the assembly is spot welded together to form the open top 101 of the bin. Figure 6 shows a cross-section through one of the square sectioned frame members 102 and illustrates the location of the flange 125 of the side panel on the upperside of the frame with the flange of the reinforcing member locating on the under surface of the frame with the reinforcing member extending externally of the bin.

The underside of the bin instead of having the four corner feet as in the first embodiment has a pair of elongate foot sections 140, 141 each comprising a rectangular panel 143 joined on one edge by a U-shaped channel member 144 with an internally facing flange 145. Each of these channel members constitute an elongate foot and they are secured to the underside of the base of the bin to raise the base off the ground and define two elongate feet which are spaced in a manner to provide tyne entry. A reinforcing flange 150 is positioned across each of the channel sections on either side to close off the open end of the channel sections and to reinforce the structure.

The completed bin defines a strong and rigid container that has the capability of carrying substantial loads without being unnecessarily heavy. Preferably, the bin is designed as either a one tonne or a two tonne bin. The tensioning of the side panels ensures that the bin adequately carries the designated weight without bowing or bulging of the sides. In a two tonne bin the side panels are made from 0.5mm thickness steel and the corner posts are rolled out of 1mm steel. Similar thickness steel is used for the base tray with the liner of the base tray being 0.7mm. In a one tonne arrangement the side panels can be of thinner material i.e. 0.35mm and the base tray and corner posts are made out of 0.7mm steel. In the one tonne embodiment although there is no angle iron in the base tray the base is formed of a single sheet of material of 0.7mm with edges bent to form the upturned flanges of

what was the angle iron of the two tonne embodiment. The return is placed on the upturned flanges so that the base tray operates in the same manner as in the two tonne arrangement where a flat sheet is welded to four pieces of angle iron to form the base tray. In the embodiment shown in Figures 5 and 6 the bin is a 2 tonne bin standing to an overall height of 1070mm. The inside depth of the bin is 995mm with the open top being 1145mm x 1240mm on the exterior and 1070mm x 1170mm on the interior. The inside walls taper downwardly so that the interior dimensions of the base are 1035mm x 1130mm.

Although not shown in the drawing it is also possible that instead of using sheet steel to line the sides and base that steel mesh is used. However, it is understood that returns would be placed on the sides and base of the steel mesh which would interlock with returns on the corner posts and base tray to ensure that the sides remain in tension to prevent bowing or bulging. It is also envisaged that when the bin is used for the transportation of liquids, powders or pastes that a suitable aseptic plastics liner may be placed within the bin to ensure against escape of the liquids.

The bins have a cross-section that reduces towards the base so that the tapered wall structure allows the bins to be stacked within one another for storage purposes. The sides of the bin may include projecting stops 155 to prevent wedging of stacked bins.

The bin has special advantages in the transportation of foodstuffs in the form of powders, liquids and pastes. Some of these liquids and pastes have a specific gravity of 1.2 and the fluid dynamics of this type of product places very large stresses on the sides of the bin during transportation. It has been demonstrated that even in the most severe situations the tensioned walls of the bin described above resist catastrophic bulging and wall distortion. The bin provides a comparatively light, very durable and strong vehicle for use for many years with

a variety of materials and products.