GB2269580A - Reinforcement of containers - Google Patents

Abstract

For maintaining the shape of a palletainer in a cold store without the use of wooden hoops and associated steel bands cardboard stiffening panels (20 - 26) are inserted into the sleeve (10) of the palletainer, one panel for each side face thereof. The stiffening panels each carry transverse V-section cardboard stiffening ribs (32) which cooperate with the flat face of the panel to resist outward bending. By providing the stiffening ribs on the inner face of the stiffening panel (20 - 26) the flat outer face thereof can cooperate face-to-face with the sleeve (10) of the palletainer for stiffening purposes. The stiffening panels provide receptor sleeves (28) for corner posts, whereby additional strength results. <IMAGE>

Description

PALLETAINERS This invention relates to palletainers.

"Palletainers" is a term used in the art to designate containers intended for use in association with pallets, to contain materials such as harvested peas and other crops for storage in a cold store. Palletainers may be used for other purposes. The invention also relates to aspects of improvements provided for use in palletainers, including improvements in relation to the structure and assembly of cardboard containers, and structural elements forming part thereof, whether such cardboard containers are used in palletainers, or otherwise. The invention provides both method and apparatus aspects of these matters.

The established mode of use of conventional palletainers is as follows. A palletainer comprises a cardboard rectangular container structure known as a "sleeve".

The container sleeve defines side walls of a container for materials. Those materials are stored in the container by placing them therein within a plastic bag which separates the materials from the cardboard sleeve. At each corner of the sleeve, and extending vertically, are four corner posts, usually of timber of 4 inches by 2 inches (10 cms x 5 cms) cross sectional dimension. These corner posts serve to transmit weight when the palletainers are stored one on top of each other. Each palletainer may contain up to one ton of material. The sleeve is provided with end flaps. The bag of material is sealed. The palletainer is placed on a conventional wooden pallet so that the palletainer can be handled by a forklift truck. The size of a palletainer is such that it can hold, for example, one ton of frozen peas.

In a warehouse, the palletainers are stored in stacks up to four palletainers high so that the weight of material within one stack may amount to four tons. Cold air circulates around the palletainers in the cold store to maintain the necessary storage temperature, for example between minus 18 degrees and minus 25 degrees celsius. The material stored within the palletainers is cooled to a suitable low temperature before being placed within the bag which is stored in a palletainer.

In order to maintain the requisite rectangular shape of the cardboard sleeve of the palletainer there is provided for each palletainer a series of four rectangular wooden hoops or frames which extend around the external periphery of the sleeve at spaced intervals up the height of the sleeve. The frames or hoops are held in place by a steel band which is strapped around the frame or hoop during assembly and holds the latter in place by means of the tension within the band.

The frame or hoop consists of four separable lengths of rectangular timber which are only held in place by the steel band. Thus, for assembly purposes a jig is needed until the band is suitably applied and tensioned.

Accordingly, it can be seen that the system of using wooden hoops or frames for sEape-defining purposes has considerable disadvantages including the cost and complexity of the wooden hoops and their associated steel bands. Also, there are associated risks to the stored product arising from splinters from the rough timbers used, and metallic debris from the steel bands and the system for tensioning, fastening and severing them. Also, the materials for the wooden hoops or frames impose considerable storage problems, and likewise for rapid delivery purposes when large numbers are required.

The wooden hoops or frames are difficult to assemble and require the use of steel strapping equipment.

An object of the invention is to provide methods and apparatus offering improvements in relation to matters discussed above and elsewhere herein, both in relation to palletainers and indeed in relation to wider aspects and applications of the invention, or improvements generally.

According to the invention there are provided apparatus and methods as defined in the accompanying claims.

In an embodiment of the invention there is provided, for use in relation to palletainers and otherwise, an internal stiffening structure or skeleton. This structure is inserted into the sleeve of the palletainer or other cardboard container. It serves to stiffen the sleeve, thereby enabling it to retain its intended rectangular or other profile without the need for external hoops or other structures.

The stiffening structure is provided on the inner side of the sleeve, for example between the plastic bag of stored material and the sleeve itself. In one embodiment, the stiffening structure is associated with and receives the corner posts of the palletainer. In another embodiment, the stiffening structure is itself in the form of a sleeve inserted into the main sleeve of the palletainer. It is thought at the time of initial filing of this application however that the principal mode of use of the invention will be in the form of four stiffening panels for the side walls of the sleeve.

In an embodiment, each stiffening panel comprises a planar panel of cardboard. The panel is for insertion into the sleeve of the palletainer so as to lie substantially faceto-face therewith. Stiffening elements are provided on the inner face of the stiffening panel. The stiffening elements extend laterally across a dimension of the stiffening panel so as, in use, to resist bending or flexing of the panel in a direction transverse to the lengthwise extent of the stiffening elements. Thus, in the embodiment, the stiffening elements extend laterally across the width of each face of the sleeve of the palletainer so as to resist outward bowing of the face in use. The stiffening elements could of course be inclined with respect to the purely transverse direction while still exerting a stiffening effect, the amount of the stiffening effect varying with the degree of inclination.

The number of stiffening elements will vary in accordance with their structure and the stiffening requirements of a particular embodiment.

Preferably, the stiffening elements are formed of cardboard. They may be formed as cardboard mouldings or cardboard fabrications. The preferred cross sectional shape of the stiffening elements is V-shaped so that the element tapers outwardly to its apex and loads applied to the stiffening element by the material within the palletainer, (such loads tending to cause outward bending of the palletainer sleeve side walls) are applied to the stiffening element in an outward direction so as to produce a largely compressive (as opposed to bending) force on the material of the stiffening element, which it is able to resist far more effectively than bending loads.

The stiffening elements may be hollow or may be provided with slide-in secondary stiffening elements, which may be profiled to fit within them. These latter elements could be of other materials such as plastic or light sheet metal.

In a typical embodiment, a stiffening panel for a palletainer comprises a flat cardboard sheet carrying four or more transverse stiffening elements or ribs of V-section, these being bonded to the cardboard sheet. Four such panels are inserted into the palletainer sleeve, one for each face with the stiffening ribs on the inboard face of each panels.

No external stiffener or shape retainer is then required for the cardboard sleeve.

In the described embodiment, there are provided four stiffening panels. These consist of two pairs. One pair provides two panels each having a receptor sleeve at its longitudinal edges, to receive the corner posts. The receptor sleeves are formed of the same cardboard material as the remainder of the panel, and indeed are formed by a folding operation. The stiffening elements extend between the receptor sleeves and abut against them. Thus, in the assembled condition of the palletainer, the receptor sleeves are provided at each corner. The other two panels cooperate with the first two panels and are provided with longitudinal edge flaps to be lodged around the receptor sleeves for location purposes.

The provision of receptor sleeves considerably enhances the strength and bend resistance of the stiffening panels. Furthermore, such provision serves further to reduce the possibility of contamination of stored materials since the rough wood of the corner posts is substantially entirely enclosed. Moreover, there is no need to provide for other location means for the container sleeve with respect to the corner posts. Therefore, the cut-outs which have hitherto been provided are not needed.

Accordingly, one aspect of the invention provides, per se, a stiffening panel for a palletainer comprising receptor sleeves for the corner posts.

The embodiment provides notable advantages in comparison with the wooden hoop system by greatly reducing costs, complexity of assembly, and weight. Moreover, delivery is simplified and the entire structure of the sleeve and its shape retaining mean is formed of cardboard, whereby the sleeve and its stiffening structures can be delivered together, and probably in assembled conditioned. Delivery, storage and cost factors are much improved. No significant reduction in storage capacity of life of the palletainer is thought likely.Though cardboard obviously does not have the strength or ability to resist dampness that wood does, the cardboard stiffening elements, or comparable ones can provide the necessary degree of stiffness to retain the shape of the palletainer sleeve, and in use there is no significant dampness applied to the cardboard, on account of the low temperatures which are maintained in the cold store.

Modifications envisaged include the use of noncardboard stiffening panels and stiffening sleeves. These could be plastic mouldings or even mild steel fabrications which could be tinned. It is foreseen that future modifications might include the use of the stiffening elements formed as integral stiffeners for the palletainer container sleeve itself, instead of being incorporated on separate panels or on an additional internal sleeve. The stiffening elements can be moulded in place, glued in place, stapled in place, or indeed mounted by means of adhesive tape. Though a V-section is the preferred shape in the case of cardboard stiffening elements, in the case of plastics mouldings or other materials, other shapes may be acceptable, including a generally semi-circular or part-circular shape, or a polygonal shape.

Important aspects of the invention include the provision of stiffening panels as such, as described above.

The use of these in relation to a sleeve in a palletainer, the provision of the stiffening panels themselves as sleeves, the incorporation of stiffening panels into the main sleeve member of a palletainer, and methods of assembly associated with these structures.

In the embodiments, the volume occupied by the stiffening panels within the confines of the sleeve of the palletainer, which necessarily correspondingly reduce the load carrying volume of the sleeve in use, can be offset by manufacturing the sleeve with a larger external dimension to an extent corresponding to the space saved by the elimination of the external wooden hoops or frames and their associated steel assembly bands. As a result, the net volume available for storage purposes is likely to be at least as great, if not more than with existing systems.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which : Fig 1 shows a perspective view of a palletainer constructed in accordance with the invention.

Fig 2 shows a perspective view of three sides of a blank from which the palletainer sleeve is formed.

Fig 3 shows a perspective view from one side of one of the pair of stiffening panels which receive the corner posts.

Fig 4 is a further perspective view from the other side of the stiffening panel of Fig 3 with detail of the sleeves for receiving the corner posts.

Fig 5 shows a perspective view of one of the second pair of stiffening panels with location flaps.

Fig 1 shows a palletainer or like produce container constructed in accordance with the invention in which the container 10 has a rectangular shape defined by front, rear and side walls 12, 14, 16, 18. Two pairs of stiffening panels 20, 22 and 24, 26 are located within the container 10. The stiffening panels 20, 22 and 24, 26, abut or lie face-to-face with the inner sides of the walls 12, 14, 16 and 18 of the container and are held in place by a friction fit and by mutual co-operation as shown.

One pair of stiffening panels 20, 22 are formed with longitudinally extending sleeves 28 at each edge of the panel within which are received the wooden corner posts (not shown).

The second pair of stiffening panels 24, 26 are formed with longitudinally extending location flaps 30 at either side of the panel to aid their location within the palletainer.

The stiffening panels 20, 22, 24, 26 are all formed with stiffening elements in form of ribs 32 of triangular cross section. The ribs 32 lie on the inner face of the stiffening panels 20, 22, 24, 26. The ribs 32 resist outward bowing of the face when the palletainer is in use.

Fig 2 shows part of a blank from which the palletainer sleeve is formed showing three of the four walls, 12, 14, 16 and base flaps 34.

Turning now to the embodiments of the invention shown in Figs 3 to 5, it will seen that Fig 3 shows one, of the first pair of stiffening panels 20, 22 with further detail of the longitudinally extending sleeves 28. The sleeves are formed by longitudinal folding of the edges of the panel 20 and are hollow as shown in Fig 4 to receive the wooden corner post (not shown). The sleeves 28 enable the corner post to be located within the container without coming into contact with the contents. Ribs 32 which are formed on the panel 20 extend between the receptor sleeves 28 and abut them. The ribs 32 have spaces 34 between them and provide selective reinforcement of the stiffening panels 20, 22 as spaces 34 provide little stiffening function. The embodiment of Fig 3 shows five ribs 32 or although more or fewer may be used as required.

Fig 5 shows one of the second pair of stiffening panels 24, 26. This panel 24 is also formed with spaced ribs 32. The longitudinal edge of this panel 24 are folded to form locating flaps 36. The flaps 36 are located around the receptor sleeves 28 for location purposes when the panel 24 is inserted into the container. The ribs 32 formed on panel 24 do not extend to the edges of the panel and abut the location flaps 36 but rather a space 38 is left between the ends of the ribs 32 and the locating flaps 36. This is to allow the receptor sleeve 28 to be correctly located without fouling the ribs 32 of panels 24, 26.

During assembly, the container sleeve 10 is formed from a blank as illustrated in Fig 2. Two pairs of stiffening panels 20, 22 and 24, 26 are inserted into the container 10.

The panels 20, 22, 24, 26 abut or lie face-to-face with the inner face of the container walls 12, 14, 16, 18. The longitudinal edges of the first pair of panels 20, 22 are folded to form the receptor sleeves 28 prior to being inserted. During insertion, the panels 20, 22 are a sliding fit and the second pair of panels 24, 26 are inserted with the longitudinal locating flaps 36 lodging around the receptor sleeve 28 so as to locate the receptor sleeve 28 in the space 38 formed between the end of the ribs 32 and the location flap 36 in order that the ribs 32 of the second pair of panels 24, 26 abut the receptor sleeveS28 as do the ribs of panels 20, 22 in order to provide the required strengthening.

Claims (21)

CLAIMS :

1 A palletainer or like produce container comprising front, rear and side walls characterised in that the front, rear and side walls are strengthened said strengthening means being provided by stiffening panels located within the container.

2 A container as claimed in claim 1 said stiffening means being selectably reinforced.

3 A container as claimed in claim 1 or claim 2 wherein said selective reinforcement is provided by ribs.

4 A container as claimed in claim 3 wherein said ribs are upstanding from the stiffening panels.

5 A container as claimed in claim 3 or claim 4 wherein said ribs are of triangular cross-section.

6 A container as claimed in claim 1 wherein said stiffening panels abut or are face-to-face with the internal face of the container walls being retained by friction fit.

7 A container as claimed in claim 1 wherein at least one panel is formed with receptor sleeves at its longitudinal edges to receive corner posts.

8 A container as claimed in claim 1 wherein at least one panel is formed with longitudinal edge flaps to be located around the receptor sleeves.

9 A palletainer or like produce container comprising front, rear and side walls characterised in that said front, rear and side walls are strengthened said strengthening means being located within the container.

10 A container as claimed in claim 9 wherein strengthening means is provided by selective reinforcement of the walls of the container.

11 A container as claimed in claim 9 or claim 10 wherein selective reinforcement is provided by means of ribs.

12 A container as claimed in claim 11 wherein said ribs are upstanding from the internal face of the walls of the container.

13 A container as claimed in claim 11 or claim 12 wherein said ribs are of triangular cross-section.

14 A method of assembling a palletainer or like produce container wherein reinforced stiffening panels are inserted into the container so as to abut or be face-to-face with the interior faces of the sides of the box and are retained in position so as to strengthen the container.

15 A palletainer or like produce container substantially herein before described with reference to the accompanying drawings.

16 A method of assembling a palletainer or like produce container substantially as herein before described with reference to the accompanying drawings.

17 A panel for use in a palletainer or like produce container as claimed in claims 1, 2, 3, 4, 5, 6, 15 and 16.

18 A container as claimed in claims 1, 2, 3, 4, 5, 6, 15 and 16 wherein said panels are provided in the form of a sleeve to fit within said walls.

19 A panel as claimed in claim 17 wherein receptor sleeves are provided at the longitudinal edges of the panel to receive the corner posts.

20 A panel as claimed in claim 17 wherein longitudinal edge flaps are provided at the longitudinal edges of the panel for location purposes

21 A container having internally strengthened front, rear and side walls.