GB2310422A - Collapsible receptacle - Google Patents

Abstract

A collapsible receptacle, particularly a mail tray, in use comprises a base with a plurality of side walls 5 extending therefrom. At least two opposing side walls each comprise first and second members that are separated by a cavity 36 and define part of the respective internal and external surfaces of the receptacle. The receptacle preferably has a further two opposing side walls with cooperating means, such as upper recesses 29 and lower lugs 13, to enable stacking of a plurality of such receptacles. The second members may have apertures 9 for handling purposes, and may have deformable portions 10 which can provide recesses for mail-handling equipment without affecting the continuity of the internal surface of the receptacle. The first members may have locating means such as lugs (25, fig 4a) which protrude through the base. The base may comprise a plurality of flaps extending from the side walls. The receptacle may have a base insert and/or a lid member, and may be made from cardboard.

Description

COLLAPSIBLE RECEPTACLE The present invention relates to a collapsible receptacle and relates particularly, but not exclusively, to a collapsible mail tray.

In Great Britain, for example, because of the large volume of mail to be handled, most mail is sorted automatically by machinery. This increasingly requiring the use of trays that can be presented to machinery for offloading and onward transport.

Such mail trays are generally in the form of rigid, rectangular open-topped crates of plastic material such as polypropylene having a base and upstanding side walls.

Recesses are provided in an opposed pair of side walls for location of parts of the cradle of a letter sorting machine tray rack or parts of destacker shelves, for example of culler-facer-canceller machines or an optical character reading machine. The trays generally have non-planar side walls and are therefore widened at the upper part thereof to have internal dimensions corresponding to the external dimensions of the lower part of the crate, to enable the trays to be stacked on top of each other when full, and nested within each other when empty.

One drawback of existing mail trays is that they are expensive to manufacture and bulky (and therefore expensive) to transport when empty. A further disadvantage arises in the case of international mail transport, since crates loaded with mail onto aircraft are frequently not returned from their destination, causing considerable wastage of relatively expensive mail trays.

Various attempts have been made to manufacture mail trays from a less expensive material, such as corrugated cardboard or plastic, but hitherto without success.

Preferred embodiments of the present invention seek to overcome the above disadvantages of the prior art.

According to the present invention, there is provided a collapsible receptacle, the receptacle in use comprising a base and a plurality of side walls extending from the base, wherein the side walls of at least one pair of opposed side walls each comprise a first member and a second member defining part of respective internal and external surfaces of the receptacle, wherein each said first member is separated from the said corresponding second member by a cavity.

By providing a collapsible receptacle in which at least one pair of opposed side walls comprise first and second members separated by a cavity, the external members of the pair of side walls can be adapted for a particular purpose, such as transport or handling of the receptacle, while the internal members can remain intact, thus maintaining the continuity of the internal surface of the receptacle.

Also, the provision of a collapsible receptacle minimises the cost and/or inconvenience of transportation of such receptacles when empty, and has the advantage of enabling the receptacle to be constructed from much less expensive materials than in the case of the prior art. In addition, the provision of side walls comprising first and second members separated by a cavity greatly enhances the strength of the receptacle when assembled, thus enabling a strong receptacle to be constructed from lightweight materials, such as cardboard.

In a preferred embodiment, the receptacle has four said side walls, comprising a first pair of opposed side walls having respective first and second members, and a second pair of opposed side walls having co-operating means at the upper and lower portions thereof to enable stacking of a plurality of said receptacles on top of each other.

By providing the co-operating means on pairs of side walls not having a cavity, the strength of the receptacle is not weakened by the provision of the co-operating means.

Preferably, the co-operating means comprises one or more recesses at the upper part of each said second pair of opposed side walls, and one or more respective lugs on the lower part of each of the second pair of opposed side walls.

In a preferred embodiment, each said recess is so shaped as to enable a corresponding lug of a further receptacle to be located therein in a substantially vertical or a substantially horizontal direction.

This provides the advantage of enabling so-called "slide stacking" of the receptacles, thus enabling receptacles filled with a greater weight of mail to be stacked manually.

In a preferred embodiment, each said first member is attached to the corresponding second member and is separated therefrom by a pair of fold lines.

This facilitates manufacture, in that by folding along the pair of fold lines, the cavity separating the first and second members is formed.

Preferably, each said second member is attached to a pair of adjacent side walls, and each said first member has locating means for locating said first member in position in the erected receptacle.

In a preferred embodiment, each said locating means protrudes through the base of the assembled receptacle.

This provides the advantage of having protrusions on the base of the assembled receptacle which can be located between upstanding side walls of a further receptacle to assist in slide stacking of receptacles on top of each other.

Each said second member may be provided with one or more respective apertures for enabling manipulation of the receptacle in use.

In this way, handles may be provided through the outer surface of the receptacle without affecting the continuity of the inner surface.

Each said second member may comprise one or more deformable portions for forming a respective recess in the second member without affecting the continuity of the inner surface of the receptacle.

This has the advantage of providing recesses which enable, for example, location of parts of the cradle of a letter sorting machine tray rack or parts of destacker shelves, for example of culler-facer-canceller machines or an optical character reading machine, while not affecting the continuity of the internal surface of the receptacle, since the parts of the machinery can be arranged not to project into the recesses beyond the cavity.

In a preferred embodiment, the base of the receptacle in use comprises a plurality of flaps, each said flap extending from a respective side wall.

The receptacle may further comprise a base insert member for location in the erected receptacle for defining a lower internal surface of the receptacle and/or providing a smooth internal bottom surface of the receptacle.

The receptacle may further comprise a lid member.

In a preferred embodiment, the lid member comprises one or more projections for location in corresponding slots in the side walls.

The receptacle may be constructed from cardboard.

In order that the invention may be better understood, a preferred embodiment of the invention will be described in detail below, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a cut out cardboard sheet for forming a collapsible mail tray embodying the present invention; Figure 2 is a perspective view of a mail tray, without lid, assembled from the cut out sheet Figure 1; Figure 3 is a partial cross-sectional view of the mail tray of Figure 2; and Figures 4a to 4e show the assembly of the mail tray of Figures 1 to 3.

Referring to Figure 1, there is shown a flat cardboard sheet, cut by any suitable method, such as die cutting, or any other such method as will be known to persons skilled in the art. The flat sheet 1 comprises an upper portion 2 and a lower portion 3 attached to each other along a line 4 which can be severed-to separate the upper 2 and lower 3 portions of the sheet 1 from each other.

The lower portion 3 comprises a pair of longer side walls 5 separated by a first shorter side wall 6, and from one of which a second shorter side wall 7 extends, the side wall 7 having a glue flap 8 at an edge thereof remote from the adjacent longer side wall 5. Each of the longer side walls 5 has a roll under handle 9 comprising a flap of cardboard continuous with the side wall 5 and attached thereto by one edge thereof, and a pair of strips 10 of cardboard, each of which is formed by a pair of slits 11 in the side 5 along its elongate edges and the purpose of which will be described in greater detail below.

Each of the shorter side walls 6, 7 has a handle aperture 12 of similar dimensions to the roll under handle 9 in the longer side walls 5, and a pair of spaced apart lugs 13 provided on the lower edge thereof.

A pair of first base members 14 are attached to respective longer side walls 5 along one edge thereof such that strips 10 extend across the line 15 at which each first base member 14 meets the corresponding longer side wall 5. Each of the first base members 14 has a pair of elongate slots 16 arranged adjacent to line 15, and a recess 17 at the side thereof opposite to line 15. A glue panel 18 is provided at a corner of each member 14 on one side of recess 17.

A pair of second base flaps 19, each of which is attached to a corresponding shorter side wall 6, 7 by means of a fold line 20 has an elongate slot 21 arranged along fold line 20.

At the upper parts of side walls 5, 6, 7, remote from base members 14, 19, a pair of first wall members 22 extend from the longer side walls 5, and are attached thereto by double fold lines 23. An elongate slot 24 is provided at the fold line furthest from the corresponding longer side wall 5.

Each of the side flaps 22 has a pair of projecting lugs 25, each of which is arranged opposite to an elongate slot 16 on the corresponding base member 14 and corresponds in size thereto.

A pair of end wall elements 26 are attached to a respective shorter side walls 6, 7 by means of single fold lines 27.

Each of the end wall elements 26 is provided with a handle aperture 28 so dimensioned and arranged that handle apertures 28 overlie the corresponding handle apertures 12 on the adjacent shorter side wall 6, 7 when the flap 26 is folded along fold line 27. The end wall elements 26 are also provided with recesses 29, corresponding in size and location to lugs 13, such that when the elements 26 are folded along fold lines 27 to overlie shorter side walls 6, 7, the recesses 29 appear at the upper part of the shorter side walls 6, 7, as shown in greater detail in Figure 2.

The upper part 2 of the cut out 1 forms a rectangular base insert 30 having a pair of generally semicircular end indentations 31, as well as a lid 32 having tabs 33 provided on each of its longer sides and corresponding to slots 24 provided in first side wall members 22.

To form the stored (i.e. collapsed) condition of the tray, glue flap 8 on shorter side wall 7 is glued to edge 34 of the longer side wall 5 furthest therefrom to form a tube of generally rectangular cross-section. The glue panel 18 of each base member 14 is then glued to the base member 19 adjacent thereto, and the box thus formed can be pressed flat in a manner known to persons skilled in the art to enable transport thereof in the most convenient (i.e. least bulky) and cost effective manner.

Referring now to Figures 4a to 4e, the mail tray is assembled from the cut out 1 by first pushing on the outer edges of the box (i.e. at side walls 5, 6, 7) to form a generally flat base from base members 14, 19 and having side walls 5, 6, 7 extending therefrom as shown in Figure 4a.

In order to form the end walls of the mail tray, end wall elements 26 are then folded along corresponding fold lines 27 and a respective tab 35 (which is narrower than the tabs 25 on the first wall members 22) provided on each end wall element 26 is located in the corresponding slot 21 provided in the base of the box 1. The overlying elements 26 and side walls 6 or 7 then form the end walls of the mail tray, and handles to enable lifting of the tray are provided in each end wall by overlying apertures 12, 28.

Referring now to Figure 4c, first wall members 22 are folded along the double fold lines 23 to overlie corresponding side walls 5, but in such a manner that a gap or cavity 36 (see Figure 3) is provided between members 22 and corresponding side walls 5, the gap having a thickness approximately equal to the distance between the separate fold lines of each double fold line 23. At the same time, lugs 25 are located in corresponding slots 16 in the base members 14 to secure the first wall members 22 in position.

Because lugs 25 are wider (i.e. extend further beyond the edge of the wall members 22 from which they are formed) than tabs 35, when the tray is assembled, the lugs 25 protrude beyond the base of the tray in such a manner that four protrusions are provided on the base of the assembled tray, the protrusions extending parallel to the longer side walls 5 and arranged at the bottom of the first wall members 22. As a result, the protrusions can be located between the first wall members 22 of a further tray so that the upper tray can be slidingly located on top of a lower tray, i.e. the protrusions provide a so-called "slide stacking" facility.

At this stage, the mail tray is as shown in Figure 2, and comprises a through handle 12, 28 in each of its end walls, each of which also has a pair of recesses 29 at its upper part, and a pair of locating lugs 13 at its lower part.

The side walls 5 each have an aperture 9 therethrough, which only extends as far as the wall member 22 lying behind the side wall 5. Each side wall 5 also has a pair of spaced apart strips 10, which can be pressed inwards to form locating recesses to locate corresponding parts of the cradle of a letter sorting machine tray rack or parts of destacker shelves without those cradle parts extending as far as the internal surface of the box as defined by first wall members 22.

Referring to Figure 4d, base piece 30 is inserted into the tray to maintain the rigidity of the tray which is then ready for use in a mail sorting operation and facilitates, by providing a smooth surface, the direct sorting of mail from a flat sorting machine.

When sorting mail to the tray, the tray is cradled by a part of the letter sorting machine rack which locates in the recesses defined by strips 10, in such a way that the tray can be filled directly from a letter sorting machine in an ergonomic posture for each individual destination.

When sufficient mail has been placed in the tray, the tray is then closed by lid 32, the lugs 33 of which are located in slots 24 in the wall members 22 as shown in Figure 4e.

The closed tray can then be transported to its destination, for example by an aircraft in which several such trays can be stacked on top of each other by location of stacking lugs 13 of one tray into recesses 29 of the tray below.

Because recesses 29 correspond generally in shape to stacking lugs 13 and are open at the internal faces thereof, when trays are stacked on top of each other by means of slide stacking, the protrusions on the base of one tray are located between the longer side walls of a further tray, and the stacking lugs of the upper tray can then be slidingly located into the corresponding recesses 29 of the lower tray.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only, and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims.

Claims (15)

CLAIMS:

1. A collapsible receptacle, the receptacle in use comprising a base and a plurality of side walls extending from the base, wherein the side walls of at least one pair of opposed side walls each comprise a first member and a second member defining part of respective internal and external surfaces of the receptacle, wherein each said first member is separated from the said corresponding second member by a cavity.

2. A receptacle according to claim 1, wherein the receptacle has four said side walls, comprising a first pair of opposed side walls having respective first and second members, and a second pair of opposed side walls having co-operating means at the upper and lower portions thereof to enable stacking of a plurality of said receptacles on top of each other.

3. A receptacle according to claim 2, wherein the cooperating means comprises one or more recesses at the upper part of each said second pair of opposed side walls, and one or more respective lugs on the lower part of each of the second pair of opposed side walls.

4. A receptacle according to claim 3, wherein each said recess is so shaped as to enable a corresponding lug of a further receptacle to be located therein in a substantially vertical or a substantially horizontal direction.

5. A receptacle according to any one of the preceding claims, wherein each said first member is attached to the corresponding second member and is separated therefrom by a pair of fold lines.

6. A receptacle according to any one of the preceding claims, wherein each said second member is attached to a pair of adjacent side walls, and each said first member has locating means for locating said first member in position in the erected receptacle.

7. A receptacle according to claim 6, wherein each said locating means protrudes through the base of the assembled receptacle.

8. A receptacle according to any one of the preceding claims, wherein each said second member is provided with one or more respective apertures for enabling manipulation of the receptacle in use.

9. A receptacle according to any one of the preceding claims, wherein each said second member comprises one or more deformable portions for forming a respective recess in the second member without affecting the continuity of the inner surface of the receptacle.

10. A receptacle according to any one of the preceding claims, wherein the base of the receptacle in use comprises a plurality of flaps, each said flap extending from a respective side wall.

11. A receptacle according to any one of the preceding claims, further comprising a base insert member for location in the erected receptacle for defining a lower internal surface of the receptacle and / or providing a smooth internal bottom surface of the receptacle.

12. A receptacle according to any one of the preceding claims, further comprising a lid member.

13. A receptacle according to claim 12, wherein the lid member comprises one or more projections for location in corresponding slots in the side walls.

14. A receptacle according to any one of the preceding claims, wherein the receptacle is constructed from cardboard.

15. A collapsible receptacle substantially as hereinbefore described with reference to the accompanying drawings.