The present invention also relates to plant pot containers with drip trays and to types of tubular containers which provide a tubular display device.

Background to the invention Flat-pack containers have been described in UK Patent Applications 2318569 and 9801318.8 and British Patent 2297965, all in the name of the Applicant and it is intended that the whole contents of these documents should be incorporated herein by reference. The information contained in these eariier documents forms an integral part of the present disclosure.

Such containers find a variety of uses such as desk ornaments. They can also be used to transport items, as pots for lightweight contents e. g. for containing pens, pencils etc. and also as waste paper baskets, plant or flowerpot containers and combined display tubular containers. The containers are often designed to be inexpensive"throw away"items, which must therefore be simple to manufacture. However, a particular problem with such containers lies in the manufacturing process for the end caps and the apertures/perforations of the tube length.

The end caps typically contain a groove of appropriate shape for the end of the tube to be fitted into. This groove contains projections formed at spaced intervals around the groove wall. These projections tend to press against the tube edge when it is fitted and lock positively into perforations/apertures in the tube edge.

Typically, the protrusions are wedge shaped and project substantially across the groove. The applicant is aware of several such containers, all of which operate on the same principle. These are described in US 4215779, EP 0059314 and US 3986659. If the end caps are manufactured using a plastics moulding method it has been found that the moulding tool used to form the groove tends to deform or knock off the protrusions as the moulding tool is withdrawn from the groove. Because the end cap material is malleable during the manufacturing process this is especially likely to occur.

Methods of avoiding this problem are known although they tend to be expensive. For example, special tools may be used to hold the walls apart before withdrawing the moulding tool. Alternatively the moulding tool may be rotated by an angle sufficient to clear the protrusion prior to withdrawal. However, using these expensive manufacturing methods mitigates against the container being an inexpensive"throw away item".

A further problem with the known flat-pack containers is that the perforations/apertures in the tube edge are difficult to form because after the outline of the perforation is cut the part of the sheet within the perforation or"cut out"has to be removed before assembly can take place. This is a very real problem because if the cutouts are removed during the manufacturing process they tend to clog up the cutting tool. This slows the manufacturing process and tends to blunt the tool.

If removal of the cutouts is left until assembly it makes the whole process tedious and time consuming.

Either way, the use of perforations/apertures which consist of substantially rectangular holes is undesirable.

Another problem is that once the wedge shaped projections are engaged into such perforations/apertures it is very difficult to remove the end cap from the tube. This makes it difficult to disassemble the flat-pack container ready for storage or transport.

It is accordingly an object of the present invention to provide a container which overcomes or at least mitigates one or more of the problems noted above.

Summary of invention According to a first aspect of the present invention, there is provided a flat- pack container comprising:- (i) a sheet of material adapted to be rolled into a tube length to form the body of the container; and (ii) top and/or bottom end caps, each end cap defining a groove corresponding to the cross-section of the tube length, wherein a wall of the groove is provided at spaced locations with projections extending into the groove; wherein the sheet is provided with appropriately shaped incisions at spaced locations corresponding to the projections.

This arrangement has the advantage that the interlocking strength is enhanced because the tube material which would otherwise have been removed during slot formation or assembly remains in place and acts like a miniature spring holding the tube in place on the protrusions.

In a preferred embodiment the incisions comprise at least one cut of discrete length wherein the cut is formed so as to fully pierce the container sheet and is aligned parallel with the adjacent edge of the container sheet and positioned so as to correspond to the projection of the end cap.

In a further preferred embodiment the projections of the inner groove wall are shaped to provide a chamfered lead-in face and a rear retaining face, whereby, for fitting, the tube end and end cap are aligned with respective projections and incisions in registration and pushed together, thereby causing portions of the tube edge adjacent the projections to be guided by the lead-in and the angled face of the projections to locate the incisions over their respective projections and to be retained by said retaining faces.

In a particular preferred embodiment each incision comprises two cuts being substantially parallel with corresponding end alignment. This arrangement provides the advantage that the region between the incision acts like a miniature spring with the length of material maintained between the cuts being deformed as the angled face of the projections urges the flexible length toward the lugs of the outer groove such that a positive lock is achieved, strong enough to allow the container, when in use, to hold weighty materials.

In a further preferred embodiment the incision comprises a cut which is substantially parallel to the longitudinal edge of the container sheet wherein a transverse cut of considerably lesser length is positioned at each end, having substantially orthogonal alignment and being continuous with the longitudinally aligned cut, said combination being commonly referred to as a flap. It is preferred that the flap is oriented such that the longitudinal edge of the flap is aligned with the

ends of the respective lateral, short cuts having closest proximity to the adjacent edge of the container sheet.

In a particularly preferred embodiment the sheet of material for the tube body incorporates foldable tabs, said tabs being adapted to engage in use with a respective tube end to prevent rotation of the tube body with respect to the tube end caps once the container is in its assembled state.

The invention has the advantage that it can be applied to a wide variety of containers of the type in question including flat pack plant pot containers with drip trays and also flat pack combined display device containers.

Preferably there is provided a plant pot container assembly comprising:- (i) a tube length adapted to form the body of the container; (ii) a bottom end cap, said cap defining a groove corresponding to the cross-section of the tube length; (iii) engagement means adapted to retain, in use, the tube in the bottom end cap; and (iv) a drip-tray positioned beneath the bottom end cap and adapted to attach to said bottom end cap such that in use liquid from a plant pot within the container drains into the drip tray.

This provides the advantage that excess water drains into the drip tray and this prevents the plant roots from rotting. Also, the drip-tray is visible to the user who is easily able to see whether there are large amounts of excess water in the drip-tray without needing to remove the plant pot from the container. Also, the plant pot container can be disassembled for storage and transport and is inexpensive to manufacture.

Preferably said drip-tray is detachably fixed to said bottom end cap. This provides the advantage that different sized drip-trays can be used with the same container. It is also possible for the drip tray to be formed as an integral part of the bottom end cap. This provides the advantage that the container does not accidentally become dislodged from the drip tray.

Advantageously, said drip-tray comprises one or more lugs protruding from the surface of the tray, said lugs being adapted to support the bottom end cap.

Said lugs may be joined together to form an annular protrusion which, in use, forms a wall of a tank within which liquid is held such that in use a humid environment can be provided around a plant in the plant pot container by allowing water held in the tank to evaporate into the container. This provides the advantage that a humid "micro environment"can be created for plants which require humidity.

Advantageously, the bottom end cap is perforated such that in use liquid may pass through the bottom of the end cap and wherein said bottom end cap is adapted to support a plant pot. Also, the plant pot container may comprise a top end cap, said cap defining an endless groove corresponding to the cross-section of the tube length.

Preferably said engagement means comprises one or more protrusion (s) in the groove wall, said protrusions being adapted to form an engaging fit with corresponding incisions (s) at the end of the tube length, this provides the advantage that when the protrusions are engaged in the incisions the end caps are effectively "locked on"to the tube.

In a further embodiment the invention provides a flat. pack container comprising:- (i) a first tube length adapted to form the body of the container;

(ii) top and bottom end caps, each cap defining a groove corresponding to the cross-section of the first tube length; (iii) engagement means adapted to retain, in use, each end of the first tube in a respective end cap; characterised in that the container further comprises a second tube length the two tube lengths being adapted to nest one within another and to be rotatable one with respect to the other, images on the two tube lengths combining to create an overall image on the tubular surface of the container. This has the advantage that two or more images can be displayed and the user can adjust the picture from time to time to provide a change.

In a preferred embodiment the outer tube rotates with respect to the inner tube and in a further preferred embodiment the outer tube is formed from substantially transparent material to which opaque stripes have been applied. In this way the outer tube can be moved relative to the inner tube to produce an animated display pattern. It is preferred that the stripes on the outer tube extend either substantially vertically from the top to the bottom of the tube or substantially horizontally around the circumference of the tube.

Advantageously the invention includes a flat-pack container comprising:- (i) a first tube length adapted to form the body of the container; (ii) top and bottom end caps, each cap defining a groove corresponding to the cross-section of the first tube length; (iii) engagement means adapted to retain, in use, each end of the first tube in a respective end cap; characterised in that the container further comprises a second tube length the two tube lengths being adapted to nest one within another and to be rotatable one with respect to the other, images on the two tube lengths combining to create

an overall image on the tubular surface of the container, wherein the engagement means comprises one or more protrusion (s) in one of the groove walls, said protrusions being adapted to form an engaging fit with corresponding incisions (s) at the end of the tube length.

In a preferred embodiment the outer tube rotates with respect to the inner tube and in a further preferred embodiment the outer tube is formed from substantially transparent material to which opaque stripes have been applied.

Advantageously, the stripes on the outer tube extend either substantially vertically from the top to the bottom of the tube or substantially horizontally around the circumference of the tube.

According to a further aspect of the present invention there is provided a flat-pack container comprising:- (i) a tube length adapted to form the body of the container; (ii) top and bottom end caps, each cap defining a groove corresponding to the cross-section of the tube length; (iii) engagement means adapted to retain, in use, each end of the tube in a respective end cap; wherein the engagement means comprises a retaining surface on one of the groove walls and one or more pre-formed indentation (s) or dimple (s) in the tube end wall. This provides the advantage that the manufacturing process is simplified and costs are reduced because it is possible to use a conventional moulding tool to form the groove profile without deforming or knocking off protrusions from the groove walls during the manufacturing process. Also, the indentations or dimples are easy to manufacture in the tube wall and it is not necessary to create actual apertures in the tube wall. This is achieved whilst at the same time obtaining

a good engagement between the end caps and the tube and allowing the end caps to be easily removed from the tube end wall for storage of the container.

Preferably the retaining surface is a protrusion or lug. In another embodiment the retaining surface comprises an indentation.

Advantageously, the retaining surface is positioned some distance up from the bottom of the groove to allow room for at least one of the indentations or dimples to nest below the retaining surface in a co-operatively engaging fit. This provides the advantage that the end caps can be securely fixed to the tube ends in a simple and effective manner.

Preferably, the one or more pre-formed indentation (s) or dimple (s) extend outwardly from the tube wall and are adapted to co-operatively engage with the retaining surface. Again this allows the end caps to be securely fixed to the tube ends in a simple and effective manner. Moreover, it is preferred that the retaining surface extends substantially continuously around one of the groove walls. This makes the retaining surface simple to manufacture and easy to use.

Preferably, the retaining surface is on the outer groove wall. This enables the retaining surface to act against the inner groove wall and the tube end wall when this is inserted into the groove.

Advantageously, the engagement means further comprises a second retaining surface on the opposing groove wall. This further improves the fixing of the end caps to the tube end wall.

Preferably the second retaining surface comprises two lugs. It is also preferred that the lugs are spaced apart on the opposing groove wall, one substantially above

and one substantially below the level of the first retaining surface. This enables the tube end wail to be gripped between the two retaining surfaces.

Advantageously, the engagement means further comprises a perforation in the tube end wall, the perforation being adapted to engage with the retaining surface. The perforation fits around the retaining surface and helps to ensure good engagement between the tube and the end cap.

Advantageously, the protrusion extends less than half way across the groove.

This makes the protrusion easy to manufacture because a conventional moulding tool can be used without deforming or knocking off the protrusion.

Preferably a container as described immediately above further comprises a second tube length the two tube lengths being adapted to nest one within another and to be rotatable one with respect to the other, images on the two tube lengths combining to create an overall image on the tubular surface of the container. It is also preferred that the outer tube rotates with respect to the inner tube. Moreover it is preferred that the outer tube is formed from substantially transparent material to which opaque stripes have been applied. Advantageously, the stripes on the outer tube extend either substantially vertically from the top to the bottom of the tube or substantially horizontal around the circumference of the tube.

Description of the Drawings The invention will be further described, by way of example only, with reference to the accompanying drawings in which: Figures 1-3 and 3A are plan views of a container sheet having different incisions; Figure 4 is an exploded, fragmenting, half-section of the tube formed from the sheet and bottom end cap;

Figure 4A is an enlarged detail of part of Figure 4; Figure 5 is a plan view of a bottom end cap; Figure 6 is a cross-section through a plant pot container assembly which contains a plant pot and where water is held in the drip-tray; Figure 7 is a cross-section through a plant pot container assembly which contains a plant pot and where the drip-tray is nearly full of water; Figure 8 is a cross-section through a plant pot container assembly with a shaped bottom end cap; Figure 9 is a plan view of a bottom end cap having perforations; Figure 10 is an exploded, fragmentary, half-section of a bottom end cap adapted for use with a flared tube, and a flared tube formed from a container sheet; and Figure 11 shows a cross-section through a tubular container with one end cap and with a double tube wall.

Figures 12 and 13 and 14 show cross sections through a groove in an end cap.

Figures 15,16 and 17 are cross sections through a groove in an end cap according to other embodiments of the invention.

Description of preferred embodiments Embodiments of the present invention are described below by way of example only. These examples represent the best ways of putting the invention into practice that are currently known to the Applicant although they are not the only ways in which this could be achieved.

As described in British Patent Application number 2297965 the tubular body may be formed from a rectangular sheet of suitable material e. g. polypropylene that is rolled into a tube and retained in this form by the end caps. Alternatively, the

tubular body may be provided as a tubular unit; this tubular unit may be folded flat for storage or transportation of the container.

Referring to Figure 1 of the drawings, a container sheet 1, which is preferably of plastics such as polypropylene, is rectangular, with a series of three flaps 2 at one end, and a corresponding series of three shaped tabs 3 at the other end, for retaining the sheet in the form of a tube 4 (see Figure 4) after rolling or folding.

Referring to Figures 4 and 5, a bottom end cap 6 is circular in this embodiment and has a peripheral wall 7 in which is defined an endless, circular groove 8 corresponding to the circular cross-section of the tube 4.

The cap in this embodiment is also preferably of plastics, such as PVC, and the end wall 9 thereof is suitably strengthened to resist significant loading, in the embodiment by ribs 10.

At spaced locations around the groove 8, corresponding to the spacing of the incisions 5, one groove wall 8A (see Figure 4A) is provided with projections each being shaped to provide a chamfered lead-in 12 and a rear retaining face 13, and the other groove wall 8B is angled towards the projection, as shown. Thus, for fitting, the tube 4 is aligned with the bottom end cap 6 with its incisions 5 in registration with the projections, which operation can be facilitated by a registration mark or projection 14 on the wall 7 of the bottom cap 6 (see Figure 5). For assembly, the two components are pushed together, whereby the lead-in chamfers 12 of projections 11 cause adjacent portions of the tube end to be pushed inwardly, and thereafter outwardly by the angle of the groove wall 8B, and hence cause respective incisions 5 to ride over and be positively retained by the retaining faces 13.

It will be appreciated that the top end cap (not shown), in the form of an annular ring, could be similarly provided with spaced projections for the incisions 5 at the top end of the tube 4.

It will be appreciated that in this invention engagement means to retain the tubular body of the container within the groove 8 of the end cap are provided by a positive interlocking between the incisions 5 in the container sheet 1 and the projections of the groove of the end cap. In this context, incision means any cut or series of cuts or penetration (s) which serve to provide a seat for projection (s) located on the groove wall, wherein the cut or cuts are shaped, positioned and aligned in any arrangement which creates a surface or surfaces capable of engaging with projection (s) to anchor the tubular container body to the end cap, and wherein the incision does not remove any material from the container sheet.

The positive interlocking between the incisions and the projections of the end cap may be achieved by using single spaced cuts to maintain the position of the container body within the end cap, as in figure 2, or by providing two parallel cuts, as in figure 1. It will be appreciated that the number of cuts per incision and number of spaced incisions along the longitudinal edge of the container sheet is determined by the arrangement of the projections of the groove.

The incisions are formed in the manufacturing process as at least one cut in substantially parallel alignment with the longitudinal edge of the container sheet.

Figure 1 illustrates a preferred embodiment of the invention in which each incision comprises two cuts of discreet length wherein the cuts fully pierce the container sheet and are substantially parallel having corresponding end alignment. The incisions are at spaced locations along the length of the longitudinal edge of the container sheet, corresponding to the spacing of the projections of the inner groove

of the end cap. This arrangement provides the advantage that the region between the incision acts like a miniature spring with the length of material maintained between the cuts being deformed as the angled face of the projections urges the flexible length toward the lugs of the outer groove such that a positive lock is achieved, strong enough to allow the container, when in use, to hold weighty materials. By using incisions instead of perforations/apertures the container sheet 1 is easier to manufacture as it is not necessary to remove the"cut out"portions.

Figures 3 and 3A illustrate a further preferred embodiment of the invention, each incision comprising a cut 5 which is substantially parallel to the longitudinal edge of the container sheet wherein a transverse cut of considerably lesser length is positioned at each end, having substantially orthogonal alignment and being continuous with the longitudinally aligned cut, said combination being commonly referred to as a flap. It is preferred that the flap is oriented such that the longitudinal edge of the flap is aligned with the ends of the respective lateral, short cuts having closest proximity to the adjacent edge of the container sheet Fitting of the container body into the groove of the end cap causes the flap to deflect. The resistance of the flap to this altered alignment causes it to behave like a spring, attempting to recoil back into alignment with the tubular body of the container, and as a consequence of this action the flap resides at the seat of the projection of the inner groove thereby providing a strong positive lock.

It will be appreciated that, due to the provision of the positive fixing, the flat- pack container, when assemble, has a far wider range of uses than heretofore.

Also, by suitable choices of materials, it can be used to contain significant weights and be weatherproof, e. g. for use as plant pots and shrub containers.

Figure 6 shows a plant pot 52 positioned within a plant pot container assembly. The container assembly comprises a tube 51 which has a top end cap (not shown) and a bottom end cap 54. The bottom end cap is perforated 56 so that liquid can drain through it. The container assembly also comprises a drip tray 53 which can be integral with the bottom end cap 54 or alternatively can be separate from the bottom end cap (as shown in figure 6). The drip tray is positioned beneath the bottom end cap and arranged to support the bottom end cap, tube and plant pot. When a plant in the plant pot is watered, any excess water drains out of the bottom of the plant pot through drainage holes 55, through the bottom end cap perforations and into the drip tray. This prevents water from the plant from damaging the surface on which the plant pot is placed and also prevents the plant roots from rotting because water cannot drain away from the pot.

As shown in figure 7 the drip tray has one or more lugs 58 which protrude from the drip tray and extend towards the bottom end cap 54. The bottom end cap is supported on these lugs. Excess liquid from the plant drains into the drip-tray and is easily visible to the user. This means that the user does not have to remove the plant pot from the plant pot container in order to check whether the plant needs watering.

It is not essential to use lugs 58 to position the drip tray beneath the bottom end cap. Any other conventional attachment means could be used, for example, a screw attachment or snap-fit fixings.

In one embodiment, the lugs are joined together and formed into an annular protrusion which acts as the wall of a tank within which liquid can be held. For example, figures 6 and 7 show lug 58 which forms the wall of a tank that holds liquid 57. The tank acts as a"humidity tank". Water held in the tank can evaporate

through the bottom end cap and around the plant pot. This enables a humid"micro environment"to be created around the plant whilst preventing the plant roots from becoming water-logged. There is a small gap 60 between the drip tray and the bottom end cap. If the"humidity tank"becomes full, excess water flows into the rest of the drip tray by passing through the gap 60 as shown in figure 6.

Figure 8 shows another embodiment where the bottom end cap 59 is shaped to facilitate drainage. In this example, the bottom end cap is concave, protruding into the plant pot container tube 51. This helps liquid to drain away from the centre of the container and into the sides of the drip tray. It is also possible to use a shaped drip tray to aid drainage. For example, the drip tray itself may be shaped in the form of a shallow cone so that liquid drains to the edges of the drip tray where it is more easily visible.

Figure 9 is a plan view of the bottom end cap which shows the perforations 21. In this example, 8 perforations are shown, although other numbers, arrangements and sizes of perforations or apertures can be used.

Figure 10 shows an example where the tube 4 is flared instead of being substantially cylindrical as in figures 6 to 8. By using a flared tube, the plant pot container is arranged to fit around a typical plant pot. Other shapes of plant pot container can be used, for example, rectangular or"box shaped"containers. Also, patterns and designs can be applied to the outer surface of the container tube to give the container a leasing appearance.

The present invention may also be applied to tubular display devices wherein the container consists of two superimposed cylinders, rotatable with respect to each other as shown in figure 11.

Striped display patterns may be presented on the surfaces of the cylinders so that when the cylinders are moved relative to one another the perception of motion is produced.

By presenting two or more images of varying animated positions in quick succession the perception of motion can be produced. This principle is used in televisions, or by presenting the images on the corners of the pages of a book and then flicking through the pages rapidly.

It is also possible to present two images simultaneously on a 2D sheet and alternately cover one of the images. For example, the display surface can be divided into striped regions of the same size, with one image being presented only on the even striped regions and the other image on the odd striped regions. Using an overlay sheet which is also divided into corresponding striped regions, with the odd stripes being transparent and the even stripes opaque (or vice versa) then relative motion between the overlay sheet and the display surface will cause the images to be covered alternately.

One problem with this method is that the overlay and display sheets need to be held in alignment whilst at the same time relative motion must be produced between them. To achieve good perceptual effects the relative motion should be smooth and fairly fast. This is often difficult to ensure especially if the method is being used by young children who find it difficult to move the overlay sheet in the correct manner and often obstruct much of the display with their hands. Another problem is that because the overlay sheet and display cannot be of infinite length as they move over each other they eventually become separated and the overlapping effect is removed. Therefore the overlay sheet (or display sheet) has to be moved back and forth which tends to make the relative motion jerky and disjunctive.

The overlay and display sheets can be presented as two superimposed cylinders, rotatable with respect to each other. This has the advantage that the overlay sheet can be moved continually in the same direction in a smooth manner so that good perceptual effects can be achieved. Also, the overlay sheet, in the form of a cylinder can be easily rotated even by a child.

Preferably, the display pattern is presented on the inner cylinder. A striped pattern may either be printed directly onto tube itself or onto the rectangular sheet used to form the inner tube. It is also possible to provide the pattern on a sheet of paper for example, and place this around the tube. This has the advantage that the display can easily be replace if it is desired to show a different image.

The striped pattern can either be arranged so that the stripes run vertically from top to bottom of the tube as assemble or so that the stripes extend horizontally, around the circumference of the tube.

The overlay and display sheets can be presented as two superimposed cylinders, rotatable with respect to each other. This has the advantage that the overlay sheet is provided in the form of a transparent rectangular sheet which has opaque stripes corresponding to those on the inner cylinder. As shown in Figure 11, the second rectangular sheet is formed into a tube 30 and placed around the outside of the first tube 31 so that the two tubes are concentric with each other.

The diameter of the second tube is slightly greater than that of the first tube so that the tubes can be moved relative to one another. As the tubes are rotated relative to one another the odd and even stripes on the first tube are alternately visible and thus the two different images are alternately visible. In this way the perception of movement can be achieved.

It has been found that the opaque stripes need not be completely opaque- it is enough to reduce the visibility of the underlying pattern by an amount sufficient to produce the desired effect. Similarly, the transparent stripes need not be completely clear.

The outer end edges of the end cap 32 provide end-stops as shown in Figure 11 which prevent the second tube 30 from sliding off the first tube 31. Both end caps can provide end-stops in this way although only one end cap is shown in Figure 11.

In one embodiment the second tube 30 is of substantially the same height as the first tube 31 as shown in Figure 11. In this case the two tubes 30 and 31 are preferably rotated relative to each other and about their common axis. The striped patterns are arranged such that the stripes run vertically along the length of the tubes. Alternatively, the second tube 30 may be of a height less than that of the first tube 31 so that the second tube 30 can either be moved up and down along a vertical axis or it can be rotated relative to the first tube 31. In the case that the second tube is moved up and down along a vertical axis the striped patterns are arranged so that the stripes run horizontally around the circumference of the tubes.

To assemble the container the first inner tube is taken and one of the end caps is attached to the bottom of the tube. (If a rectangular sheet is provided this is first formed into a tube as described in British Patent Application number 2297965.) A sheet of paper or other material displaying the striped pattern may be fixed around the first tube at this stage using glue, tape or any other conventional fixing means. The second tube is placed around the first tube as shown in Figure 11 and the other end cap is attached to top of the tube. Whilst holding either/both end caps the second tube can then be moved easily relative to the first tube and the

perception of motion produced. In this way two or more images can be produced and the user can adjust the picture from time to time to provide a change.

The second tube may be formed from flexible material, preferably plastics material that is transparent. Opaque stripes are printed or applied using any other conventional means to the second tube.

Figures 12 and 13 show cross sections though part of an improved end cap according to another aspect of the present invention. The end cap 100 contains a groove 102 that has an outer wall 103 and an inner wall 104. The tube end 105 is positioned inside the groove as shown. A retaining surface 106,107 is provided on one of the groove walls, in this example, on the outer wall 103 and the retaining surface comprises two protrusions 106 and 107. The protrusions 106 and 107 are spaced apart such that one is substantially vertically above the other as shown in Figure 12. The other groove wall, in this example, the inner wall 104 is provided with a lug 108. The lug 108 is provided by a protrusion in the inner wall as shown and is directed towards the retaining surface 106,107. Preferably the lug 108 is directed towards the space between the two protrusions 106 and 107 as shown in Figure 12.

In a preferred embodiment the lug 108 is provided by a protrusion that forms a ring around the groove wall in the end cap. Alternatively, lugs 108 can be provided as protrusions spaced at intervals around the groove wall.

When the tube end 105 is placed into the groove 102 it is flexed about the lug 108 which tends to force the tube end towards the outer groove wall 103. At the same time the protrusions 106 and 107 tend to force the tube end towards the inner groove wall 104. As a result of these forces the tube end flexes as shown in Figure

12 and tends to be retained within the groove. If the tube end is pulled up vertically out of the groove the lug 108 and the protrusions 106 and 107 act to prevent the tube end from being withdrawn from the groove.

Once the tube end wall is flexed in this way indentations 113,114 and 115 form as shown in Figure 12. The protrusions 106,107 and the lug 108 fit into these indentations in the tube wall so that the tube is held firmly in the end cap. The indentations can also be pre-formed in the tube. For example, if the tube is made from plastics material then the indentations can be formed by heat treating the end of the tube.

The indentations or dimples, 113,114 and 115 can be formed simply as a consequence of the flexing or bending of the tube end wall as it is pushed into the end cap. Alternatively, the dimples or indentations may be pre-formed in the tube end wall. This can be done during the manufacturing process, for example by moulding, or heat treating the tube end wall.

This method of using indentations or dimples in the tube end wall to hold the tube in place around protrusions or lugs in the end cap can be used with many types of flat-pack container. For example, it can be used with flat-pack containers that have two nested tubes as shown in Figure 11 and it can also be used for flat- pack containers which have only one tube, for example those described in GB 2297965.

As shown in Figure 12 the lug 108 and the protrusions 106 and 107 do not need to extend more than half way across the groove and they may be rectangular.

Also the lug 108 and the protrusions 106 and 107 are not necessarily wedge shaped. This means that during the manufacturing process it is possible to use a conventional moulding tool to form the groove profile without deforming or knocking

off the protrusions 106,107 or 108 from the groove walls when the moulding tool is withdrawn.

It is also possible for the protrusions and the lug to be tapered or wedged for example as shown in Figure 14. The lower face of the protrusions and lugs have sloping edges 120 as shown. The gradient of these sloping edges may be adjusted to suit the particular moulding tool and design requirements. Once the edges are sloping then this helps the moulding tool used to form the groove profile to be withdrawn without damaging the protrusions 106,107 or 108.

Figure 13 shows another embodiment of the invention where the tube end contains a perforation 109 as described in British Patent Application number 2297965. Protrusion 108 fits at least partial into the perforation 109 to enable the tube end to engage positively with the end cap. The protrusions 106 and 107 act to push the tube end towards the lug 108 so that the perforation 109 engages with it.

The combined effect of this engaging mechanism and the flexing of the tube end around the lug 108 and protrusions 106 and 107 ensure that the tube end is held within the groove.

It is also possible to use a protrusion on only one groove wall together with an indentation in the tube to engage with the protrusion. For example consider the situation in Figure 1. If protrusions 106 and 107 are not provided the outer groove wall 103 can itself act to retain the tube end wall against the lug 108. The tube is then held in the end cap 101.

Figures 15 and 16 show a further embodiment of this aspect of the present invention. In this example the end cap 130 contains a groove 132 comprising an inner wall 134 and an outer wall 133. The tube end is positioned within the groove as shown. The retaining surface in this example comprises a protrusion or nib 137

which projects into the groove. The nib 137 is positioned some distance up from the bottom of the groove to allow room for an outwardly extending dimple 136 to nest below it in a co-operatively engaging fit. The dimple 136 may be formed by deforming the end of the tube in the required region. Methods and equipment for forming such distending dimples are known per se to the person skilled in the art.

They usually involve the application of pressure or heat or both whilst forcing the tube material into an appropriately shaped die.

Accordingly, there is often a corresponding indentation (as shown in figure 15) in the side of the tube wall opposite the side containing the dimple. This can co- operatively engage with a further protrusion 138 (not shown) on the inner groove wall 134. This may act to form a more secure fit of the tube wall within the groove but requires rather more careful engineering.

Figure 17 shows a further embodiment of the present invention. In this example, the end cap 140 contains a groove 142 comprising an inner wall 144 and an outer wall 143. The tube end is positioned within the groove as shown.

The retaining surface in this example comprises a channel 147 which extends for substantially the whole circumference of the groove. The channel 147 is positioned some distance up from the bottom of the groove such that when the tube end is engaged in the groove an outwardly extending dimple 136 nests within it in a co-operatively engaging fit.

An indentation, positioned in the side of the tube wall opposite the side containing the dimple co-operatively engages with a further protrusion or lug 148 on the inner groove wall 144. In an alternative embodiment, the corresponding indentation may be absent and the wall of the tube may then be flexed about the protrusion of lug 148 such that the tube end is urged towards the outer groove wall

143. This has the effect of ensuring a more secure fit of the tube wall within the groove.

In principle, the protrusion or nib can take a wide variety of forms. Any extension or projection from one of the groove walls into the groove which can co- operatively engage with a pre-formed shape on the tube wall such that there is a snug, engaging fit will suffice.

With regards to the shape of nib 137, this is illustrated in Figure 15 as a ridge with generally rounded edges. Unlike the prior art, where a wedge-shaped protrusion is essential to engage firmly with an aperture in the tube wall, this is no longer necessary. Any shape with an engaging surface 139 directed substantially towards the bottom of the groove will suffice.

In fact, the chamfered rounded edges on the nib 137 offer definite advantages. They simplify manufacture considerably and ease the passage of the tube end as it is forced into the bottom of the groove.

In a preferred version the nib 137 runs substantially the whole circumference of the groove. Once again, this arrangement is simple to manufacture. The dimples may be spaced periodically around the tube wall end. Their spacing is not critical, providing they are distanced from the edge of the tube wall end to form a tight engaging fit with the nibs/ridge 137 once inserted.

It is also possible for the dimple 136 to extend for substantially the whole length of the tube end. Once again this may simplify manufacture because the tube ends can simply pass through a heated roller/die during the production process.

The ribs 10 shown in Figure 5 can also serve another purpose as well as acting as strengtheners. They can be arranged to urge the tube body against the outer groove wall. That is to say, the ribs 10 may extend almost to the outer groove

wall, leaving a gap substantially equivalent to the thickness of the tube material.

This arrangement provides a particularly solid feel to the assemble product.

This arrangement also creates discreet cavities or sectioned off areas 151 within the perimeter of the end cap. It has unexpectedly been discovered that, by forming foldable tabs 150 in the edges of the tube body, these engage in these cavities to prevent rotation of the tube with respect to the end cap. This prevents inadvertent dis-assembly of the container.

In practice the tabs 150 are formed by making two small cuts in the edge of the sheet and at right angles to the edge. Perforations are formed parallel to the edge of the sheet and in a line between the two cuts and displaced from the edge of the sheet by a dimension substantially the same as the depth of each cut.

During assembly these tabs 150 are bent inwards towards the centre of the container. They then automatically engage with one of the cavities 151.

Whilst one tab is sufficient to add rotational stability, it is preferable to include a plurality of tabs at each end of the tube.

In this context the term"tab"has a broad meaning. It is intended to encompass any size or shape of feature adapted to engage with a corresponding feature in an end cap.

This modification can be applied to any of the containers previously described herein.