In particular, this invention relates to improvements devices used in the edging and paving of gardens. However, reference to edging and paving of gardens should not be seen to be limiting the scope of the present invention in any way, as the present invention may be used to edge other areas such as driveways, tarseal, pathways and so forth.

BACKGROUND ART Edging for various arrangements is commonly used to improve the appearance and aesthetic qualities of particular areas. Such areas may be a garden, a pathway, a driveway or other sealed or paved surface or some other areas - generally outside.

Common methods of edging include pouring concrete or cement into a predefined mould around the contour of the area one is trying to edge, and allowing it to set. This process is time-consuming and labour intensive.

Another problem that arises from such a method is that soil and other substrates tend to move through erosion, vibrations, and so forth. The rigidness and relative inflexibility of the hardened cement or concrete means that such an edging may crack under these stresses. This detracts from the aesthetic quality of the edging, and defeats the purpose of the edging, being the creation of an aesthetic quality.

Other methods may include the laying if paving bricks or tiles in a particular arrangement.

This can be particularly time consuming and laborious as the bricks or tiles are often heavy, and require an edging cement to retain the paving tiles, bricks or edges in place.

The labour costs can increase the overall cost of such an edging, as one must often get a skilled labourer to do the work.

The problems associated with vibrations, soil movement associated with solid concrete edging may also befall the laying of bricks or paving tiles.

As they are commonly retained in cement, the structure is relatively rigid and inflexible, and therefore cracking due, to inflexibility and resistance to movements in the soil substrates, can occur.

The abovementioned cracking can be expensive or difficult to repair, and detracts from the aesthetic qualities of the edging.

One solution to the above problems is to simply place the bricks or tiles into the soil surface and allow them to sit freely. A problem with this method is that the bricks or tiles may be parted during the soil or substrate movements or vibrations which may allow weeds or grass or other flora to grow between the cracks in the paving bricks.

This can detract from the aesthetic quality of the edging. Furthermore, there may be uneven gaps caused by lateral movement between adjacent bricks which may also cause the edging to become less appealing in appearance.

Some methods and devices have been devised to alleviate these problems. One method is disclosed in New Zealand Patent No. 225374. This relates to a paving block with a top layer bonded to a concrete base. Although this is more directed to a paving block then a garden edging block, it could conceivably be used as edging. The lateral margin between the edge of the base and the edge of the upper surface means that when the pavement that the paving block is a part of is subject to deformation, the bricks will not chip against one another as has previously been the case.

However, this does not overcome the problems associated with paving or edging blocks that a adjacent to one another separating due to ground deformation, and consequently detracting from aesthetic quality and allowing weeds to grow which may further deform the edging or pavement.

Furthermore, the solid nature of the base means that an entire"ditch"must be formed to place the paving block in the ground. In other words, a volume of soil marked out by the volume of the dimensions of the brick must be removed from the ground in order to place the brick.

New Zealand Patent No. 259477 relates to a device with a base plate that has tubular projections attached to it. The base plate is placed in the aforementioned ditch, and paving stones are placed between the projections which hold the paving stones in place.

This method of forming a paving or edging structure overcomes a few of the problems including lateral movement resulting in cracking and deformation.

However, this method is conceivably expensive as not only must the blocks be purchased, but the base must also be purchased. Furthermore, the entire volume marked out by the base in combination with the paving stones must be removed from the soil surface or substrate before the base and blocks may be put in place.

New Zealand Patent No. 205134 discloses interlocking pavers or blocks whose sides are trapezoidal and angled. The particular arrangement of these pavers results in an interlocking mesh of paving with some resistance to movement when put in combination with other like pavers.

The above method provides some resistance to ground movement, however the entire volume of the paver, marked out by its dimensions, must be removed from the soil.

This can be laborious, time consuming and therefore expensive. The gaps formed by the pavers requires filling which may add to the cost.

The above disclosed pavers would not be practically suited to edging applications.

New Zealand Patent No. 248750 discloses a garden fencing or edging apparatus that has rigid elements such as blocks that are connected by a flexible wire. This method prevents lateral movement between adjacent blocks, however, the entire volume marked out by the dimensions of the blocks must be removed from the soil.

Furthermore, one must cut the adjoining wires if a break in the edging is required, which is time consuming and requires wire cutters which may cause an inconvenience.

New Zealand Patent No. 287257 discloses a method of forming blocks. The blocks in question have a central keyhole-shaped passage through which joining elements may be inserted. For example, in one embodiment the above invention is placed over a continuous line of an edging support. In another embodiment short segments of edging support are placed between adjacent blocks inserted into the keyhole.

Although this method holds the block in place, it does not prevent substantial lateral side movement between adjacent blocks as the stability is greater perpendicular to the length of the block than in the direction parallel to the length of the block. Therefore the blocks may conceivably slide along the edging support causes gaps to appear and detracting from the aesthetic qualities of the edging. Furthermore, if the top of the edging is desired to be at the same level as the surface of the soil, then a volume of soil must be removed that is equal to the volume marked out by the dimensions of the block. The additional step of providing a support is labourious and labour intensive and increases the costs of installing the block in the desired manner.

What is needed then is an edging or paving block that alleviates or minimises the foregoing problems.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided a block, the block including : a plurality of walls, at least one upper surface whose outline contours the upper edges of the walls, at least one cavity in at least one of the walls, the block characterised in that a joining element removably fixable to and mateable with at least one cavity, may connect adjacent like blocks via the joining element.

In preferred embodiments, the present invention may have a top surface only.

Reference to a block will hereafter be referred to in the context of a block used in edging or paving an area. The area may include a garden, footpath or other path, a sealed area such as a road, a concrete area, a pond, lake, and so forth.

In preferred embodiments, the present invention may be used as garden edging.

Reference to the block will be referred to hereafter as an edging block.

Reference to an edging block should not be seen to be limiting the scope of the present invention, as the principles of the present invention may be applied in applications other than edging, such as paving or bank reinforcement, without departing from the scope of the present invention.

In preferred embodiments, the walls may be configured to be substantially vertical.

However, in other embodiments, depending on the application to which the present invention is applied, the walls may be configured at other angles relative to the vertical. Thus, reference to the side walls being substantially vertical should not be seen to be limiting the scope of the present invention in any way.

The upper surface may preferably be substantially flat.

Reference to a substantially flat surface may include a flat surface that has additional material added to it which may provide a contour. In other embodiments, the surface may be stepped or provide a contour that is applicable to the particular application the edging block is used in.

For example, if a stepped or other pattern is required then the surface may be modified to accommodate this.

In some embodiments, the present invention may be bead blasted on its surfaces as this gives a less artificial look to the product.

The present invention will preferably be configured so as to be suited to the contour of the terrain the edging block is placed in. For example, if the terrain is sloping, and the edging block surface is required to be in line with the slope, then the surface may be configured thus.

Alternatively, the block surface may be required to be at an angle different from that of the slope of the terrain, and the block surface may be configured thus.

The walls may be configured to also correspond to the terrain the block is used in connection with. Thus, they may be polygonal, rectangular, trapezoidal, triangular and so forth.

However, the side walls may be preferably parallel with other side walls in terms of the dimension parallel to the line through the top and bottom edges of the side walls.

Preferably, the walls may be substantially rectangular when viewed from side-on.

The joining element may be any device that is capable of fitting into the cavity and being located in such a manner so as to resist lateral movement between adjoining blocks.

Preferably, the joining element may be moveable vertically with respect to the sides and it may have some free play in that dimension.

Reference to the joining element may now be made with reference to a key.

Reference to the joining element as a key is purely for convenience and should not be seen to be limiting the scope of the present invention in any way.

In preferred embodiments, the cavity may be any three dimensional cavity capable of receiving the key in such a manner so as to resist lateral movement between the key and the block.

Preferably, the cavity may allow some free play to the key, in the plane of the side wall.

The number of side walls may vary with the chosen outline shape of the edging block.

This outline shape may vary depending on the application and the placement or position of the particular block in the arrangement.

For example, a corner or curved portion of the edging may required curved side walls with end side walls containing the aperture and cavity.

Alternatively, the plane outline may be triangular) trapezoidai, or some other polygonal shape. In other embodiments, the plane outline may embody any closed curve shape.

According to another aspect of the present invention there is provided a method of forming a contour for an area characterised in the steps of placing a block as herein discussed in a contouring position, placing an adjacent like block next to the first block, joining the blocks which a joining element as previously described.

In some embodiments, the above method may include the step of providing a force that causes the block to be embedded in the terrain.

The present invention provides for a block for edging or paving that has several advantages over the prior art.

The present invention provides for a resistance against lateral movement between adjacent blocks in an edging or paving arrangement.

The key is placed in adjacent cavities of adjacent blocks, and provides resistance against this lateral movement.

The present invention may be manufactured out of any suitable material. This may include ceramics, nylon, Kevlar", concrete, metal, wood, glass, plastics and so forth.

The correct choice of materials can improve the ease with which the block can be embedded in the terrain.

Furthermore, the provision of one surface at the top of the block, means that the block may be placed on the soil or other surface the block is to be applied to, and hammered or forced into the ground without the need to remove a volume of soil equal to that defined by the dimensions of the block.

This is because a large portion of the volume described by the block is empty space.

The bottom of the block is open to an area defined by the lower edges of the side walls.

Therefore the hammering or forcing of the block into the ground or other surface may be effected, as the side walls may penetrate the surface of the ground to a depth defined by their height and the resistance against the top surface.

Therefore, a person need not spend time and effort and possibly money digging a ditch or other cavity in the ground to enable the present invention to be used as a paver or edger.

The free play provided by the cavity for the key in the plane of the side wall that the cavity is in, allows different contours of the ground to be followed by the edging while still maintaining the advantages of the present invention.

In some applications, the present invention may be used as a fire break, for example, if made from a fire-resistant material.

BRIEF DESCRIPTION OF DRAWINGS Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which : Figure 1 shows one aspect of the present invention, and Figure 2 shows the joining element of the present invention, and Figure 3 shows a further configuration of the present invention, and Figure 4 shows a further configuration of the present invention, and Figure 5 shows a further configuration of the present invention, and Figure 6A- 6E shows plan views of the embodiments shown in Figures 1 to 5.

BEST MODES FOR CARRYING OUT THE INVENTION With reference to Figure 1 there is shown a block to be used in paving or edging show by general arrow 1. The block of Figure 1 includes side walls 2 and end walls 3. The end walls 3 include a cavity 4. The bottom edge of the side and end walls are substantially in the same plane and are shown by arrow 5. The top surface 6 is substantially flat.

According to Figure 2, there is shown a key by general 20. The key includes at one end projections 21 and at its other end projections 22.

The cavity 4 in Figure 1 extends at its inner end towards the side walls 2 at either side.

This extension is shown by arrow 7.

The extensions 7 combined with the opening of the cavity 4 are commensurate with the projections 21 or 22 of the key 20 in Figure 2.

The projections 21 may slot into the cavity 4 from the bottom edge 5 of the block 1.

An adjacent block (not shown) may have the projections 22 at the other end of the key 20 slotted into its corresponding cavity at its corresponding bottom edge.

In this way, the blocks are joined together such that lateral movement is resisted.

The bottom edge 2 may be placed on the terrain, to which the block is to be embedded. and force applied to the surface 6, for example in the form of a hammer, which may cause the bottom edge 5 to be embedded into the terrain.

With reference to Figure 6A and 6B, the mating of the key shown by 6B into the cavity 4 with the outwardly extending extensions 7 can be seen from the corresponding plan views 6A and 6B.

With reference to Figure 3, there is shown a block 30 that has essentially the same functional features as that shown in Figure 1, however the side walls 32 are curved.

This has the advantage of being able to configure curved paving and edging arrangements.

For example, a circular or other closed curve arrangement may be formed.

The cavity 34, substantially the same as the cavity 4 in Figure 1, is commensurate with the key 20 shown in Figure 2, in the same manner as the block 1 in Figure 1. The end walls 33 contain the cavity 34 which, when aligned with adjacent blocks with a corresponding cavity, are mated with the projections on the key 20, and are hence joined.

The bottom edge 35 of the block 30 may be placed on the terrain to which the block 30 is to be embedded, and force supplied to the surface 36 so as to embed the block 30 in the terrain.

With reference to Figure 4 there is shown a block 40 that functions in the same manner as the previous blocks. There are two walls 41 and 42 that contain identical cavities 43 and 44. The planes of the walls 41 and 42 are substantially perpendicular.

The bottom edge 45 of the block 40 is placed on the terrain and a force applied to the top surface 46 thereby embedding the block 40 in the terrain. The block 40 may be used as a right angle connector between other blocks.

The cavities 43 and 44 are commensurate with the key 20 in Figures 1 and 3.

With reference to Figure 5 there is shown a block 50 whose end walls 51 and 52 contain identical cavities 53 and 54 that are of substantially the same configuration as the cavities of previous blocks in the previous figures.

The end walls 51 and 52 are disposed at an angle relative to each other. The bottom edge 55 is placed on the terrain and force applied to the surface 56, to insert the block 50 in the terrain. The cavities 53 and 54 are commensurate with the key in Figure 2 and connect to adjacent blocks with similar cavities as previously described in the previous figures.

With reference to Figures 6A to 6E, there is shown plan views of the configurations shown in Figures 1 to 5.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.