GB2223481A

GB2223481A - Nestable and stackable containers

Info

Publication number: GB2223481A
Application number: GB8823727A
Authority: GB
Inventors: David Arthur Williams
Original assignee: Lin Pac Mouldings Ltd
Current assignee: Linpac Mouldings Ltd
Priority date: 1988-10-10
Filing date: 1988-10-10
Publication date: 1990-04-11
Anticipated expiration: 2008-10-10
Also published as: GB2223481B; GB8823727D0

Abstract

A container preferably moulded as one piece in plastics has at each corner 4 an external hollow buttress 5 which provides an interior recess 8 having an upwardly open mouth 9 so that when two containers are nested the buttresses 5 of the upper container are received within the respective recesses 8. Bridging each corner 4 is a flexible strip 10 which is displaceable over a platform 7 from an outer condition which permits nesting to an inner condition for stacking in which the foot 6 of each buttress of an upper container rests on a strip 10 of the lower container. The strips 10 are preferably of corrugated profile and each is displaceable through a dead centre condition between its inner and outer conditions to be biased by its natural resilience to the inner or outer condition as selected. <IMAGE>

Description

TITLE "A container TECHNICAL FIELD & BACKGROUND ART The present invention relates to a container and is particularly concerned with open top containers having a base and upwardly extending side walls and means by which similar containers can either be nested one within another or stacked vertically on each other.

Containers which can be nested vertically one within another when empty are particularly convenient for storage and transport and it is desirable that such containers can also be vertically stacked one on another (with their bases spaced, usually, slightly less than the height of the respective side walls) for the storage and handling of the containers when loaded. Typical containers having the aforementioned vertical stacking and nesting facility are often referred to as tote boxes for the handling of food produce.

To provide a vertical stacking capability it is known for open top containers to be provided with abutments which are carried by the side walls and are displaceable between an inner and an outer condition. In their outer condition the abutments permit two similar containers to be nested and in their inner condition the abutments permit two similar containers to be stacked vertically with the upper container resting on the abutments of the lower container.

Conventionally, the abutments are in the form of rods, frames or similar components of a rigid nature which are pivotally or hingedly mounted on the side walls to be displaceable between their inner and outer conditions.

The provision of the aforementioned hinged or pivoted abutments is often an expensive feature to manufacture and/or assembly as part of the container. It is an object of the present invention to provide a container of the kind previously discussed and which lends itself to relatively simple and inexpensive manufacture in the provision of the abutments and in which the abutments are easy to use and can readily be incorporated as a part of the container structure.

STATEMENT OF INVENTION & ADVANTAGES According to the present invention there is provided a container comprising a base; walls extending upwardly from the base and diverging with respect to each other to permit two similar containers to be nested vertically one within the other; abutment means carried by the walls spaced from the base and being displaceable between an outer condition which permits two similar containers to be nested and an inner condition in which two similar containers can be stacked vertically with the upper container being supported on the abutment means of the lower container and wherein the abutment means comprises peripherally spaced flexible strips each of which is secured at its opposite ends so that the length of the strip is greater than the distance between its secured ends, each said strip being displaceable through a dead centre condition between the inner and outer conditions and being biased by its natural resilience to the inner or outer condition as selected.

By the present invention it is envisaged that the container will have two or more flexible strips spaced about its periphery and which can be flipped manually from their inner conditions to their outer conditions or vice versa as required for nesting or stacking respectively.

The strips will usually be of plastics material and in a preferred container structure are formed integral with the walls of a plastics moulded container.

It is preferred that the strips are displaceable between their inner and outer conditions in a plane which is generally parallel to the container base. In its inner condition a strip may be supported along part of its length on a flange, platform, shoulder or similar support surface of the container wall to alleviate distortion of the strip when it is subjected to the load from a container which is column stacked on it.

Although the flexible strips can be located in a side wall which may be substantially flat or provided with a slight curve in plan, it is preferred that a strip is located to bridge what may be regarded as a corner of the container in plan. A most popular open topped container or tote box is of rectangular shape in plan and with such a design four flexible strips can be provided one at each of the four corners so that these strips, in their outer conditions, follow the generally rectangular profile of the container.

Preferably each flexible strip has associated therewith a rib or buttress which is located on the exterior of the container wall to extend downwardly from that strip and to generally converge as it approaches the container base. The rib or buttress is hollow to provide a recess on the interior of the container which recess has an upwardly open mouth and is located and sized so that when two similar containers are similarly orientated and nested one within the other, the exterior ribs or buttress of the upper container are received within the recesses formed by the respectively corresponding ribs or buttresses of the lower container - for such nesting the respective flexible strips are located in their outer conditions clear of the mouths of the respectively associated recesses.To achieve column stacking the flexible strips are displaced to their respective inner conditions to overlie the mouths of the recesses of their respectively associated external ribs or buttresses so that when one container is positioned on a similarly orientated underlying container, the bottom ends of the respective ribs or buttresses engage with the flexible strips (so that the latter prevent the ribs or buttresses from moving into the recesses as would be necessary for nest stacking). The aforementioned mouths of the recess may be located in shoulders of the container which are substantially parallel to the base so that the shoulders provide support surfaces as aforementioned for a major part length of the flexible strips when the latter are in their inner conditions.

To facilitate their flexing, and provide for their load bearing, the strips may have a corrugated or similar ribbed profile with the corrugations or ribs extending upwardly with respect to the base.

DRAWINGS One embodiment of an open topped container will now be described, by way of example only, with reference to the accompanying illustrative drawings in which: Figure 1 is a perspective view of the container; Figure 2 is a plan view of a corner part of the container, and Figure 3 is a section through the corner part of Figure 2 taken on the line III - III and shows the manner in which two similar containers can be column stacked.

DETAILED DESCRIPTION OF DRAWINGS The container illustrated is injection moulded in plastics, such as polypropylene, as a one piece unit and is of generally oblong rectangular configuration in plan having a substantially flat base 1 and opposed side walls 2 and opposed end walls 3 extending upwardly from the base to form an open top. The walls 2 and 3 diverge from each other as they recede from the base 1 to provide a slightly tapered configuration to the container whereby two such containers, similarly orientated can be nested vertically one within another so that a major part of the depth of the upper container is accommodated within the side and end walls of the lower container.

The four upstanding corners 4 of the rectangular configuration each have substantially the same structure which comprises an upstanding buttress 5 that is located on the exterior of the container and extends over the major depth of the container from a foot 6 at the bottom of the container to a platform or shoulder 7 which is slightly below the open top of the container and is substantially parallel with the base 1. The buttress 5 is tapered to converge as it approaches the foot 6 from the platform 7 and is hollow to provide a recess 8 on the interior of the container walls. The recess 8 has a mouth 9 which opens upwardly in the platform 7.The recesses 8 and mouths 9 are arranged so that when two containers are nested vertically one within another, the exterior buttresses 5 of the upper container are received within the interior recesses 8 of the lower container as the buttresses of the upper container are lowered through the open mouths 9 of the lower container.

Located in each corner 4 at a position adjacent to and above the platform 7 is a flexible strip 10, the length of which extends substantially parallel to the base 1.

The strip 10 has its opposite ends 11 and 12 secured to the side walls 2 and 3 respectively by those ends being integrally moulded with the side walls. Each strip 10 effectively bridges the corner formed between the side walls to which it is attached and has a length greater than the rectilinear distance between the positions at which the ends 11 and 12 are attached to those walls. As a consequence, the strip 10 can be flipped manually through a dead centre condition and between inner and outer conditions with respect to the container side walls so that the natural resilience of the plastics for the flexible strip will retain that strip in either its inner or outer condition as selected.In its outer condition as shown at 10A in Figures 2 and 3, the flexible strip 10 is clear of the recess mouth 9 and conveniently follows the general rectangular configuration presented by the container walls; consequently with the strips 10 in their outer conditions 10A two similar containers can be nested one within the other as previously described since the strips 10 do not impede entry of the buttresses 5 into the recesses 8. It will be noted from Figures 2 and 3 that when the strips 10 are in their outer condition they move clear of their respectively associated platforms 7 and this is desirable to facilitate moulding of the strips 10.

When the strips 10 are flipped to their inner conditions as shown at 10B in Figures 2 and 3, each strip overlies the mouth 9 of the recess for the buttress 5 with which it is associated. Consequently, two similarly orientated containers can be stacked as a vertical column by the feet 6 at the bottom of the buttresses 5 of the upper container engaging over the strips 10B (as is best seen in Figure 3) so that the strips prevent the buttresses 5 from entering the recesses 8 and therefore provide column stacking. It will be realised that in a stack the load of an upper container is taken on the walls of a lower container through the flexible strips of the lower container.With this in mind it is preferred that when the strips 10 are flipped from their outer condition 10A to their inner condition 10B they move closely (preferably in sliding contact) over the respective platforms 7 and thatwhen the strips are in their inner conditions 10B an appreciable part length of the strips 10 is supported on the respective platforms 7 to alleviate distortion of the strips.

As is best seen in Figures 1 and 2, each strip 10 has a corrugated profile with the corrugations extending upwardly with respect to the base 1. This profile is preferred to facilitate flexing of the strips and also so that the effective vertical ribs which are provided in their strips by the corrugations permit relatively thin.strips to accommodate, without distortion, considerable loading': from: one or more overlying containers during column stacking.

For convenience, in Figure 1 the nearest corner is shown with its flexible strip 10 in the inner condition while the three other corners are shown with their respective flexible strips in the outer condition.

Claims

1. A container comprising a base; walls extending upwardly from the base and diverging with respect to each other to permit two similar containers to be nested vertically one within the other; abutment means carried by the walls spaced from the base and being displaceable between an outer condition which permits two similar containers to be nested and an inner condition in which two similar containers can be stacked vertically with the upper container being supported on the abutment means of the lower container and wherein the abutment means comprises peripherally spaced flexible strips each of which is secured at its opposite ends so that the length of the strip is greater than the distance between its secured ends, each said strip being displaceable through a dead centre condition between the inner and outer conditions and being biased by its natural resilience to the inner or outer condition as selected.

2. A container as claimed in claim 1 in which the flexible strips are of plastics material.

3. A container as claimed in either claim 1 or claim 2 and of plastics material with the flexible strips integrally moulded therewith.

4. A container as claimed in any one of the preceding claims in which the flexible strips are displaceable between their inner and outer conditions generally parallel to the base.

5. A container as claimed in any one of the preceding claims in which the flexible strips are provided with ribs which extend in a direction upwardly with respect to the base.

6. A container as claimed in any one of the preceding claims in which the flexible strips have a corrugated profile with the corrugations extending upwardly with respect to the base.

7. A container as claimed in any one of the preceding claims in which the walls have a support surface by which a strip is supported along part of its length when in its inner condition to alleviate distortion of that strip when it is subjected to the load of a container which is vertically stacked on it.

8. A container as claimed in any one of the preceding claims and having at least one corner which, in plan, is bridged by a flexible strip.

9. A container as claimed in claim 8 and of rectangular shape in plan and wherein four flexible strips are provided one at each of the four corners cf the rectangular shape.

10. A container as claimed in claim 9 in which each of the four strips in its outer condition substantially follows the general rectangular shape of the container.

11. A container as claimed in any one of the preceding claims in which at least one flexible strip has associated therewith a rib or buttress which is located on the exterior of the container wall to extend downwardly from that strip, said rib or buttress being hollow to provide a recess on the interior of the container which recess has an upwardly open mouth and is arranged so that when two similar containers are nested one within the other, the exterior rib or buttress of the upper container is received within the recess formed by the respectively corresponding rib or buttress of the lower container, said nesting being achievable when the flexible strip is located in its outer condition clear of the mouth of the respectively associated recess and for vertical stacking the flexible strip is displaced to its inner condition to overlie the mouth of the recesses of its respectively associated external rib or buttress so that when one container is positioned on a similarly orientated underlying container, the rib or buttress of the upper container engages with the flexible strip of the lower container so the latter flexible strip prevents the rib or buttress from moving into the recess.

12. A container as claimed in claim 11 when appendant to claim 7 in which the mouth of the recess is located in a shoulder, flange or platform of the container walls to provide the support surface over which the flexible strip is displaceable to be supported in its inner condition.

13. A container substantially as herein described with reference to the accompanying illustrative drawings.