Aspects of the invention relate to a kerb unit and a method for manufacturing the same. Kerb stones are generally used to edge a roadway, where a raised pavement /footpath or road shoulder meets an unraised street or roadway. Typically, kerb stones are made from concrete, but there is a growing trend in moving from concrete kerb stones to kerb units made from recycled plastics material. Kerb units not only act to separate the roadway from a pavement /footpath, they also act as a gutter to aid drainage of the roadway. Drainage kerb units generally comprise an integral drainage channel through the kerb and a plurality of holes in the outer surface of the kerb to allow water to enter the drainage channel from the roadway .

As a result of the drainage function of kerb units, it is necessary to provide a seal between adjacent kerb units to prevent leakage out of the drainage channel that may damage the roadway and prevent proper drainage. Typically, when installing kerb stones, the installer applies a mastic sealant on a face of one kerb stone and abuts this kerb stone with an adjacent kerb stone such that the mastic sealant provides a seal between the kerb stones. This process has a number of drawbacks. Firstly, having to apply a sealant to a kerb stone on site is time consuming and lengthens the installation process. Also, the sealant can be messy and may provide an untidy finish to the kerb. It is therefore desirable to provide a kerb unit which addresses at least some of the above problems to some extent .

According to a first aspect of the invention, there is provided a kerb unit, comprising: a kerb body having first and second opposed end faces, at least one of which having an integrally moulded gasket; wherein the kerb unit is arranged to be placed adjacent to a second kerb unit, such that the gasket is disposed between and provides a seal between the adjacent kerb units.

First and second openings may be provided in the first and second faces respectively, and wherein at least part of a drainage channel may be defined in the kerb body between the first and second openings. At least a portion of the gasket may be provided around the periphery of at least one of the openings. The gasket may be provided over at least a portion of the surface of at least one of the faces.

The kerb unit may further comprise a protrusion and a corresponding recess on the opposed faces, wherein, the protrusion may arranged to engage with the recess of an adjacent kerb unit. There may be a plurality of

protrusions and a plurality of corresponding recesses. The or each protrusion and the or each recesses may be arranged such that there is a snap fit engagement.

The kerb body may comprise a drainage passageway providing fluid communication between the exterior of the kerb body and the drainage channel, such that in use water may be drained into the drainage channel. The drainage passageway may extend through a side wall of the kerb body. According to another aspect of the invention, the is provided a kerb unit comprising: upper and lower kerb body portions coupled together along a longitudinal axis of the kerb and having a gasket disposed between, wherein the gasket is integrally moulded onto one of the kerb body portions .

The upper and lower kerb body portions may comprise a corresponding protrusion and recess that engage with one another so as to couple the upper and lower kerb body portions respectively. There may be a plurality of protrusions and a plurality of corresponding recesses. The or each protrusion and the or each recess may be arranged such that there is a snap fit engagement.

The coupled upper and lower kerb body portions may form a kerb body having first and second opposed end faces, at least one of which having an integrally moulded gasket; wherein the kerb unit may be arranged to be placed adjacent to a second kerb unit, such that the gasket is disposed between and provides a seal between the adjacent kerb units.

First and second openings are provided in the first and second faces respectively, and wherein at least part of a drainage channel may be defined in the kerb body between the first and second openings. At least a portion of the gasket is provided around the periphery of at least one of the openings. The gasket may be provided over at least a portion of the surface of at least one of the faces.

The kerb unit may further comprise a protrusion and a corresponding recess on the opposed faces, wherein, the protrusion may be arranged to engage with the recess of an adjacent kerb unit. There may be a plurality of

protrusions and a plurality of corresponding recesses. The or each protrusion and the or each recesses may be arranged such that there is a snap fit engagement. The kerb body may comprise a drainage passageway providing fluid communication between the exterior of the kerb body and the drainage channel, such that in use water can be drained into the drainage channel. The drainage passageway may extend through a side wall of the kerb body. The kerb unit may be made from plastics material. The kerb unit may be a moulded unit. The kerb body and the gasket may be moulded from different plastics material. The kerb body may be formed of recycled plastics material and the gasket may be formed of a rubberised thermoplastic material (thermoplastic elastomers TPE) having high elastic properties .

According to another aspect of the invention, there is provided a method of manufacturing a kerb unit, comprising: a first step of moulding, in which the body of the kerb unit is formed out of a plastics material, the body

comprising a first and second opposed end faces; and over- moulding a gasket onto an end face of the kerb body.

According to another aspect of the invention, there is provided a method of manufacturing a kerb unit, comprising: a first step of moulding, in which an upper kerb body portion of the kerb unit is formed out of a plastics material; a second step of moulding, in which a lower kerb body portion of the kerb unit is formed out of the plastics material, the base portion comprising a second contact surface; and over-moulding a gasket onto the first contact surface or the second contact surface. The method may further comprise over-moulding a gasket onto an end face of the upper kerb body portion and a corresponding end face of the lower kerb body portion.

According to another aspect of the invention, there is provided a kit of parts comprising parts arranged to be assembled to form a kerb unit.

The invention may comprise any combination of the features and/or limitations referred to herein, except combinations of such features as are mutually exclusive. Embodiments of the present invention will now be described, by way of example, with reference to the

accompanying drawings, in which:

Figure 1 shows the kerb unit according to an

embodiment of the invention; Figure 2 shows the kerb unit according to another embodiment of the invention;

Figure 3 shows the rear view of figures 1 and 2;

Figure 4 shows the kerb unit according to another embodiment of the invention; Figure 5 shows top portion of the kerb unit of figure

4;

Figure 6 shows the base portion of the kerb unit of figure 4.

Figure 1 shows a moulded kerb unit 100 according to an embodiment of the invention, having a kerb body comprising a first face 102, a second opposite face 104 and side walls 106 and 108 connecting the first face 102 to the second face 104. An opening 110 is provided in the first face 102 and is connected to an opening 112 (not shown) in the second face 104 via a drainage channel that is formed trough the kerb unit 100, between the first opening 110 and the second opening 112. The drainage channel allows water to pass through the kerb unit. A hole or recess 114 is provided in a fist side wall 106, which allows water to enter the drainage channel from the road surface. The hole or recess 114 may be a drainage passageway that provide fluid communication between the exterior of the kerb unit and the drainage channel within the kerb unit. Although only one drainage passageway 114 is shown, a plurality of drainage passageways may be provided.

Kerb unit 100 may be installed in the conventional manner. In other words, the kerb may be installed at the edge of a roadway, such that the level the road surface is at the base of the opening 114 and the level of the

pavement or footpath surface is at the top level of the kerb unit 100.

An integrally formed gasket 116 is provided on the first face 102 of the kerb unit 100. In the embodiment shown in figure 1, the integrally formed gasket 116 is provided around the periphery of the opening 110 in the first face 102.

The integrally formed gasket 116 acts to create a seal between the first face 102 of kerb unit 100 and the second face of an adjacent kerb unit, when a plurality of kerb units are installed adjacent to each other. By creating a seal around the opening 110 in the first face 102 and the opening 112 in the second face of an adjacent kerb unit, a water tight seal is provided that prevents water from leaking out of the drainage channel between adjacent kerb units . Kerb unit 100 is also provided with a plurality of protrusions 118 on the first face 102 that are arranged such that they engage with corresponding recesses 120 on the second face 104 of an adjacent kerb unit. Although the figure shows the protrusions on the first face and recesses on the second face, in an alternative embodiment, the protrusions may be provided on the second face and with the recesses on the first face.

In figure 1, the protrusions 118 are shown as snap fit connectors that when inserted into the recesses 120, engage with the recesses to provide a snap fit connection. As would be understood, any suitable type of connector may be used in order to couple adjacent kerb units together.

When adjacent kerb units are assembled together, the engagement of the protrusions and recesses (clips) is such that the gasket is under compression. The compression of the gasket helps to maintain a watertight seal between adjacent kerb units.

Also, when adjacent kerb units are assembled, the clipping features are designed in such a way that

rotational movement from one kerb unit to its adjacent kerb units is possible while still compressing the gasket sufficiently enough to provide a watertight seal. This allows assembled kerb units to follow curvatures and undulations which naturally occur along roadsides.

Figure 2 shows an embodiment of the present invention in which an integrally formed gasket 122 is provided over the entire area of the first face 102. Gasket 122 will generally perform the same function as gasket 116 in figure 1, and will provide a seal over the whole area of the surfaces between adjacent kerb units. Figure 3 is an alternative view of the kerb unit of figures 1 and 2. Figure 3 shows the second face 104 with the second opening 112. Figure 3 also shows the plurality of recesses 120 that are arranged to engage with the plurality of corresponding protrusions 118.

As can be seen from the figures, and in particular figure 3, the kerb unit is formed with a ribbed structure. The ribbed structure maintains the shape and strength of the kerb unit, but also decreases the weight of the kerb unit.

The moulded kerb unit of figures 1 to 3 may be made of plastics material by injection moulding. A suitable material for the kerb body may include a wide range of recyclable Polypropylene materials (PP) . Almost any grade can be considered from recyclable general packaging to virgin automotive PP grades. However, in order to improve the environmental impact of the kerb unit, when compared with the concrete alternatives, it is desirable to use a recyclable carton packaging. A ^x blowing agent' may also added (approximately 2% but can vary) to the kerb body material. This agent gives off gases when exposed to high temperatures during the moulding process, creating a ^x honeycomb' type cross-sectional effect within the tool cavity. This allows the formation of thick wall sections (typically 15mm but can go considerably higher) to enhance the product strength and rigidity.

The integrally formed gasket may be made of a second different type of plastics material. Suitable materials for the gasket include rubberised thermoplastic materials (thermoplastic elastomers TPE) having high elastic

properties. These thermoplastic elastomers include

styrenic block copolymers, polyolefin blends, elastomeric alloys, thermoplastic polyurethanes , thermoplastic

copolyester and thermoplastic polyamides.

The body of the kerb unit may be made by any suitable injection moulding technique. The integrally moulded gasket is formed onto the kerb body during a second stage of the injection moulding process, sometimes called a

'second shot' , such that it permanently coupled to the kerb body. This over-moulding bonds the gasket to the kerb body such that the kerb body and gasket can be treated as a single unit for installation purposes.

The two stage moulding process for the kerb unit may include the following steps.

• A single tool is configured with separate cavities for the kerb body and the gasket. · The Kerb body cavity is injected first (i.e. the main moulding) , with the kerb body material to form the kerb body.

• Once the kerb body has cooled to a specific

temperature, the gasket cavity is rotated into position such that the gasket cavity is in the desired location on the kerb body.

• The gasket cavity is then injected (with TPE)

utilising a separate injection unit.

• The gasket then bonds with the kerb body as both

materials cool simultaneously.

In other words, both the material for the kerb body and the material for the gasket are injected into separate cavities configured into a single tool, which bond as they cool together, forming a single integrally moulded product.

The kerb unit of the present invention provides a number of advantages over conventional kerb stones.

Firstly, the kerb stone is lightweight, permitting a single user to install the unit. Also, the kerb unit is

manufactured as a ready to install unit. During the installation process, a user can install a plurality of kerb units without needing to apply any other products to seal the kerb units together. Further, once adjacent kerb units are placed together, a seal is immediately formed and it is not necessary to wait for any sealant to go off.

Finally, adjacent kerb units are urged together by the connecting means, such as the protrusions and recesses shown in figures 1 to 3.

Kerb units are usually provided in two unit sizes, namely a half meter long unit and a one meter long unit. In view of the moulding capabilities of conventional injection moulding machines, it may not be possible to form the body of a one meter long kerb unit in a single stage of moulding. It may therefore be necessary to provide a modular kerb unit which is moulded from a number of

individually moulded sections. Figure 4 shows such a kerb unit 200. In figure 4, kerb unit 200 comprises an upper kerb body portion 202 and a lower kerb body portion 204. The top portion 202 is arranged to engage with the base portion 204, such that a one meter long kerb unit is formed by the integration of the two parts. When the top portion and the base portion are integrated together, the kerb unit 200 functions essentially the same as the kerb unit 100 in figures 1 to 3, except that is of a longer length. As in the embodiments shown in figures 1 to 3, the kerb unit 200 comprises a drainage channel that extends through the kerb unit from a first opening in a first face to a second opening in a second opposite face. Although not shown in figure 4, one or more holes may be provided in the side walls of the kerb unit to allow water to enter the drainage channel from the road surface. The holes may be drainage passageways that provide fluid communication between the exterior of the kerb unit and the drainage channel within the kerb unit.

Figure 5 shows the top portion 202 of the kerb unit 200. As can be seen in figure 5, top portion 202 includes a first contact surface 210 that is arranged to contact a corresponding contact surface on the base portion 204. An integrally formed gasket (not shown) may be provided on the first contact surface 210. The integrally formed gasket acts to create a water tight seal along the first contact surface between the top portion 202 and the base portion 204. The integrally formed gasket may be formed onto the top portion 202 using the same two stage moulding process as described above.

Top portion 202 further includes a plurality of protrusions 220 that are arranged to engage with

corresponding recesses on the base portion 204. The

protrusions and recesses act to securely hold the top portion 202 and base portion 204 together.

When the top portion (upper kerb body portion) 202 and the base portion (lower kerb body portion) 204 are

assembled together, the engagement of the protrusions and recesses (clips) is such that the gasket is under

compression. The compression of the gasket helps to maintain a watertight seal between adjacent kerb units. Figure 6 shows base portion 204 of the kerb unit 200. As can be seen in figure 6, base portion 204 includes a second contact surface 230 that is arranged to contact the corresponding first contact surface 210 on the top portion 202. An integrally formed gasket (not shown) may be provided on the second contact surface 230. The integrally formed gasket acts to create a water tight seal along the second contact surface between the top portion 202 and the base portion 204. The integrally formed gasket may be formed onto the base portion 202 using the same two stage moulding process as described above. An integrally formed gasket may be provided on the first contact surface 210 of the top portion 202, on the second contact surface 230 of the base portion 204, or alternatively, it may be provided on both the first and second contact surfaces.

Base portion 204 further includes a plurality of recesses 240 that are arranged to engage with the

corresponding protrusions 220 on the top portion 202.

The protrusions and recesses may form a snap fit arrangement that act to securely hold the top portion 202 and base portion 204 together. Alternatively, the top and base portions may be held together by other suitable connecting means.

The integrally formed seal between the top and base portions act to seal the interior of the drainage channel and prevent water from leaking out of the drainage channel along the length of the kerb unit.

In addition to the integrally formed gasket between the top and base portions, an additional integrally formed gasket may be provided on one face of the kerb unit in a similar manner to that shown in figures 1 or 2, such that when a plurality of kerb units 200 are installed, the gasket creates a seal between the first face of one kerb unit and the second face of an adjacent kerb unit.

The moulded kerb unit 200 of figures 4 to 6 may be made of plastics material by injection moulding. The plastics material may be recycled plastics material. The body of the kerb unit may be made by any suitable injection moulding technique. Integrally moulded gaskets may be formed onto the kerb unit during a second stage of the injection moulding process.

In order to mould kerb unit 200, a first step of moulding may include moulding a top portion having a first contact surface, moulding a base portion having a second contact surface and moulding an integrally moulded gasket on the first contact surface or the second contact surface. A further moulding step may include moulding a gasket onto a first face of the top portion and a first face of the base portion, to provide the above mentioned seal between adjacent kerb units. Like kerb unit 100, kerb unit 200 is manufactured in a condition that is ready to install. A single user can install the kerb units and it is not necessary to use additional material during the installation process.

Whilst endeavouring in the foregoing specification to draw attention to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon .