GB2076366A

GB2076366A - Stackable crates

Info

Publication number: GB2076366A
Application number: GB8016629A
Authority: GB
Original assignee: Georg Utz AG
Current assignee: Georg Utz AG
Priority date: 1980-05-20
Filing date: 1980-05-20
Publication date: 1981-12-02
Also published as: GB2076366B

Abstract

A stackable plastics crate particularly for fruit has corners which are constructed as a hollow uprights (9) in order to increase load-carrying capacity. Steel tubes may be fitted in the hollow uprights to transmit stack pressure to crate feet (6). <IMAGE>

Description

SPECIFICATION Stackable plastics crate This invention relates to a stackable plastics crate, more particularly a fruit crate.

For the storage of fruit in cold rooms, the fruit crates are stacked to form tall towers and are left for long periods. In these conditions the bottom crates are subjected to high loading pressures of as much as 5 tonnes.

Injection moulding is a suitable process for the rational production of such crates, but the readily flowing thermoplastics materials used tend to distort under continuous high loading, and this is of course undesirable. To increase strength the crates are conventionally provided with external reinforcing ribs and this not only gives the crate an unpleasant appearance but makes only an insignificant contribution to reducing the ultimate distortion.

An objection of the invention, therefore, is to provide a stackable plastics crate of the kind referred to hereinbefore, such crate being rationally manufactured by injection moulding, having a much higher strength than the known crates, and undergoing little or no distortion even under constant loading over long periods.

To this end, according to the invention, the corners of the crate are contructed in the form of vertical hollow uprights. Advantageously, in order further to stiffen the crate, vertical supports may be fitted in the corner uprights to transmit the stack pressure downwardly on to the crate feet. In one advantageous aspect of the invention, these supports are in the form of steel tubes which are supported at the bottom by means of the crate feet and which bear against locating members at the top. The locating members may have studs or recesses and serve for alignment of the crates on stacking.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings of which Figure 1 is a perspective of a stackable fruit crate made from plastics; Figure 2 is a view of the underside of a base strip; Figure 3 is a cross-section through the base strip on the line Ill-Ill in Figure 4, part of the crate being shown in broken lines; Figure 4 is a plan view of the base strip; Figure 5 is a cross-section through a centering device comprising a stud, on the line V-V in Figure 6; Figure 6 is a plan view of the centering device shown in Figure 5; Figure 7is a cross-section through a centering device comprising a recess; Figure 8 is a perspective view of another embodiment of a crate for general storage;; Figure 9 is a longitudinal section through a corner upright of the crate shown in Figure 8; Figure 10 is a longitudinal section through the top part of another corner upright of the crate shown in Figure 8; and Figure ii is an elevation of a stack of empty crates, the openings of the two crates facing one another.

The iniection-moulded rectannular fruit crate shown in Figure 1 has walls 1-4, a bottom 5, and feet 6, which are fitted on to two base strips 13.

Near the top edges 7 which define the crate opening are four horizontal reinforcing ribs 8. The crate corner edges are formed by four vertical hollow sections 9 which are open at the bottom and closed at the top. These corner uprights 9 are substantially triangular in cross-section and taper upwardly, so that the crate can be stripped off the injection tool after moulding in the usual manner.

The bottom extensions of the corner uprights 9 form the feet 6.

Another four vertical reinforcing members 10 are provided centrally in the walls 1 - 4 each pair of corner uprights 9. These central uprights 10 are of rectangular cross-section and are also hollow and taper upwardly. Two of the centre uprights 10 are extended at the bottom to form feet and are fitted onto the base strip 13. The feet 6 could be closed by caps (not shown) instead of by a base strip 13.

The bottom 5 of the crate consists of a flat base plate 11 with a downwardly projecting network of reinforcing ribs 12.

The corner uprights 9, centre uprights 10, top edges 7 with the horizontal ribs 8, and the edges of the bottom 5 define eight flat non-ribbed wall portions 14, which are formed with ventilating or drainage apertures 15. Other apertures 15 are provided in the base plate 11.

Elongate horizontal slots 16 are formed between the wall parts 14 and the base plate 11 to allow water to flow off if the crate has been immersed in a water bath for removal of the fruit.

Recesses 17 in the form of handles are provided in the centre posts 10 to facilitate handling of the empty crate.

The feet 6, which are open at the bottom, are covered by the base strips 13. These are also made from plastics material and comprise three elongate ribs 18 having upwardly extending projections 19 which fit into the corresponding feet 6 and act as studs to close the feet apertures. The strips 13 may, for example, be bolted or screwed to the feet 6.

To ensure accurate alignment of the crates when they are stacked one upon the other, positioning or locating members 20, 21 are inserted and screwed into the top ends of the corner uprights 9. Two diagonally opposite members 20 are provided with studs 22, while the other two members 21 have recesses 23 into which the studs 22 fit. Only four recesses 24 are provided at the corresponding places on the underside of the base strip.

The crates have, for example, a capacity of 300 kg of apples. For storage purposes the crates are disposed one upon the other by means of a fork-lift truck, it being possible to stack ten or more crates.

The bottom crates are subjected to very high loading in these conditions for relatively long periods of time, which may be six months or more. However, no deformation occurs because the crate is of high rigidity. The material used for the crate is polyethylene, which is preferably obtained as a recycling material which can thus be put to good use.

Another crate as shown in Figures 8 to 11 compris es a non-apertured base 5 and non-apertured walls 1-4. This container is suitable for accommodating general goods for storage. The feet 6 are formed integrally with the two base strips 13 and not with the top part of the crate.

Each base strip 13 has three upwardly projecting feet 6, the strip and the feet being moulded together in the form of a skid 25. The skids are screwed or bolted to the bottom of the container. The feet 6 have upwardly extending projections 19 engaging in and retained by the openings in the uprights.

In order further to increase the crate strength and prevent any distortion under very high loads, stell tubes 27 are provided as additional supports in the four corner uprights 9. The tubes could be replaced by wooden, plastics or metal supports in the corner uprights 9 and, if required, in the centre uprights 10 as well.

To assemble the crate, the centering members 20, 21 are first pushed into the corner uprights 9. The studs 22 then project from the recesses 28 at the corners of the top edge 7, while the locating members 21 comprising the recesses 23 are retained in the apertures 23 by their edge 29.

The locating members 20, 21 have downwardly extending retaining pins 29 over which the steel tubes 27 are fitted. The opposite ends of the steel tubes 27 are held in the feet 6 by the pins 26. The ends of the steel tubes 27 are supported on metal washers 30. The skids 25 are secured to the top part of the crate by the screws 31, which also rigidly secure the still tubes in the uprights.

When a number of crates are stacked, the steel tubes 27 take some of the compression forces and transmit them directly downwards, thus preventing any distortion of the crate.

As will be apparent from Figure 11, empty crates for transport can be stacked with the crate openings facing one another. Athird crate can then be placed on edge in the interior cavity formed by this pair of crates, so that the crates can be transported in threes when empty.

The universal large-capacity crate with its integrated feet as described above advantageously has a base area of 100 x 120 cm corresponding to a standard pallet. Despite the economic use of ribs, it is extremely stable and absolutely secure when stacked. It may be supplied with slotted or nonslotted walls and bases, and in various heights. The load-carrying capacity is at least 600 kg and, when stacked, at least 5,000 kg. The preferred embodiment is without the pallet centre web, thus avoiding any damage to material projecting above the top edge when the crates are stacked. However, the crate can be constructed with a pallet centre web.

Claims

1. A stackable plastics crate, wherein the corners of the crate are constructed in the form of hollow uprights.

2. A crate according to claim 1, and comprising further hollow uprights in the walls of the crate centrally between the corner uprights.

3. A crate according to claim 1, wherein, the edge of the crate defining the crate opening has a number of horizontal reinforcing ribs and the crate bottom comprises a flat base plate having a downwardly extending network of ribs.

4. A crate according to claims 2 and 3, wherein the corner uprights, centre uprights, reinforced top edge and the edge of the bottom define eight rectangular non-ribbed wall parts.

5. A crate according to claim 4, comprising elongate horizontal drainage slots formed between the wall parts and the base plate and ventilation or drainage apertures in the wall parts.

6. A crate according to claim 1 or 2, wherein the hollow uprights are extended downwards to form feet.

7. A crate according to claim 6, characterised in that the hollow feet are covered by two parallel base strips inserted and screwed into the feet.

8. A crate according to claim 2, and having hand holes formed in an upper region of the centre hollow uprights, to facilitate handling of the crate.

9. A crate according to claim 1, wherein the corner uprights are triangular in cross-section.

10. A crate according to claim 1 and comprising two skids having upwardly projecting feet, secured to the bottom of the crate.

11. Acrate according to claim 1, wherein two locating studs and, diagonally opposite the latter, two locating recesses are provided at the corners of the top edge of the crate.

12. A crate according to claim 11, wherein the studs and recesses are provided and recesses are provided on four locating members which are accommodated within the corner uprights and are held by apertures in the top edge of the crate.

13. A crate according to claim 1, wherein vertical supports are fitted at least at the corner uprights to transmit stack pressure downwardly to the crate feet.

14. A crate according to claims 12 and 13, wherein the vertical supports are metal tubes which are supported on the locating members and in the crate feet.

15. A crate according to claim 14, wherein pins projecting into the metal tubes are provided on the locating members and in the feet.

16. A crate according to claim 15, wherein the ends of the metal tubes rest on metal washers.

17. A crate according to claim 11,and having four locating recesses at the bottom of the crate in the corners thereof.

18. A stackable plastics crate constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.