The present invention relates to a system and component for forming a surface drain, and in particular, although not exclusively, to forming a surface water drainage channel or linear drainage channel.

It is known to form a surface drain from a U-shaped open channel having a removable grate covering the open top and installed level with the finished surface. An example is described in GB2351992, which is reproduced as Figure 1 . Here the U-shaped open channel is described as an extruded UPVC section, but other materials such as concrete have also been used. The U-shaped channel forms an underground duct through which surface water is drained to a suitable location. Multiple U-shaped channels are typically installed in end-to-end relationship and sealed to each other in order to form a longitudinal drain for draining a surface area. The U-shaped channels are typically haunched in concrete to maintain them in place. Surface drains are used in a variety of environments to drain surface areas such as driveways, car-parks, and other hard surface areas including commercial and industrial hard standing areas.

The removable grate comprises a plurality of apertures through which surface water is drained into the underlying channel. The number and size of the apertures are selected to provide the minimum capacity of the drain. Sufficient capacity is required to drain the surface water. The surrounding surface is laid up to the U-shaped channel so that the grate sits flush with the finished surface. However, it is also known to replace the removable grate with a permanent cover having an upwardly extending slot. Here, the U-shaped channel sits deeper in the ground structure with the slot extending up through the surrounding surface finish so that a slot drain is created.

It is an aim of the present invention to provide an improved drainage system and component. It is a further aim to provide a single piece component that can be easily moulded. It is a further aim to provide an improved method of casting a single piece component for a drainage system.

According to some examples there is provided a component for a surface drain, a surface drain including the component and a method of forming said surface drain as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows. According to an example a single piece drainage component has a duct extending through the drainage component from one end face to a second end face. A channel is provided in an upper face of the drainage component. A slot is formed to connect the channel to the duct. The slot is formed in end faces of the drainage component.

Advantageously, the component can be easily moulded. This allows the component to be manufactured using similar processes to the manufacture of surrounding blocks or materials, thereby allowing the drainage components to blend with the surround surface materials.

In the examples, the component is arranged for transportation of liquid. Suitably, the duct is closed and extends through the component, as opposed to an open duct extending in a surface of the component. That is, the duct forms a bed in which liquid is retained and passed through the component. Suitably, the bed is closed from below so that any liquid that drains into the duct is retained to exit through the opening in the end faces. In use, liquid can be transported through the component and into an adjacent component with minimal or no loss of liquid. Ultimately, by laying adjacent units, a drainage channel is provided wherein liquid is transported to, for example, a drainage pipe or sink. The drainage system is a point drainage system and because the liquid is not drained under the area of the drain, but transported away, high drainage rates can be achieved as the drainage does not rely on the liquid permeating through a subgrade and ground under the units.

In the examples, the channel is closed to the duct except by the slot. Furthermore, the channel may extend generally parallel to the duct. However, other channel designs are envisaged. For instance, the channel may extend at an angle to the duct, such that although the channels extend from one side of each component to the other, the drainage system is formed to have a series of discontinuous channels arranged diagonal to the direction of the drainage system. Whilst the resulting channel arrangement is discontinuous, water draining perpendicularly across the drainage system would still be caught by a part of a channel arrangement. Furthermore, whilst the channels are described herein as being substantially straight, other arrangements are envisaged, for instance arcuate or waves or other complex shapes.

In the examples, the channel is formed from one or more discrete channel segments or sections. The or each discrete channel segment may be formed along an edge of the component. Additionally or alternatively, the or each discrete channel segment may be formed in the upper face spaced from the edges. Two or more of the discrete channel segments may be formed parallel to each other. Additionally or alternatively, two or more of the discrete channel segments may be formed at angles to each other. For example, two discrete channel segments may be formed at an angle to one another, which each discrete channel segment being substantially straight. Preferably, the channel is elongate, having a depth and width substantially less than a length of the channel. For instance, the width and depth may be substantially equal, or the depth may be greater than the width and may be at least 50% or at least 100% greater. In these examples, a definitive channel is formed and this may assist the water flow. However, it is also envisaged that the channel may have other shapes and, for instance, may have a width that is greater than the depth and, for instance, may be substantially greater in width than in depth.

In the examples, the channel comprises one or more discrete channel segments, each having a first side face and a base. The side face extends at an angle to the upper face. For instance, the side face extends perpendicular to the end face or at a steep angle thereto. The base extends at an angle to the side face, and preferably parallel to the upper face. Consequently, the angle between the side face and base provides a constraint to retain and guide water. When the discrete channel segment is arranged on an edge of the component, no further faces may be present. That is, the channel is open to the edge of the component. Here, a channel having a wide base is formed with the base of the channel terminating at an edge of the component, and, in use, a second opposed face of the channel being formed by an adjacent module or surface. That is, the channel is open laterally and arranged for being closed off. In such an example, this arrangement may alternatively be described as a recess formed along an edge of the component, the recess being arranged for forming a channel.

In the examples, the channels of the component are formed in use between the component and an adjacent body. For example, the channels may be formed between the component and an adjacent paving stone, slab or another component.

Alternatively, when a shallow-based channel profile is provided, such as a v-shaped channel or other geometry where two side faces meet at a point or near point, the component includes a chamfered edge, wherein the chamfered edge provides one side of the channel, and an edge or face of an adjacent module or surface meets the chamfer at an angle to provide the channel. When the discrete channel is arranged in the upper face, a second side face is provided. Typically, the second side face mirrors the first about the centre of the base, but asymmetric arrangements are also envisaged. In the case of a shallow-based channel profile such as a V-shaped channel or other geometry where the two side faces meet at a point or near point, the base becomes negligible.

In the examples, the upper face is substantially planar. In an alternative example, the upper face may include one or more steps. Here, a portion of the upper face on one side of a channel may be arranged at an angle or on a spaced parallel plane to a portion of the upper face on the other side of the channel. Consequently, a kerb unit may be provided.

In some examples, the slot is formed in at least one end face of the component. That is, the slot extends along an end face of the component. The slot is open towards the end face in which it is formed. That is, the slot is not closed off. In such an example, this arrangement may be described alternatively as a cutaway or a cutaway portion formed along an end face and arranged to form a slot. The slot may be formed, in particular, when the drainage unit is installed as part of a drainage system.

In the examples, the slot is formed from one or two discrete slot segments or sections formed in one or both ends of the component respectively. The slot preferably extends between the upper face and the duct. The slot forms side walls. The side walls may be substantially parallel or arranged to converge or diverge with respect to the drainage direction of the water. In one example, one or both side walls are arranged relative to upper surface substantially perpendicularly. In an alternative example, one or both side walls are arranged at an angle to the upper surface. Whilst the examples are described in relation to substantially straight side walls, curved, faceted or arcuate walls are also envisaged.

In the examples, the or each discrete slot segment is open to the or each discrete channel to connect the channel and duct.

According to an exemplary method, a plurality of drainage components is installed to form a drainage system. Here, each adjacent drainage component is in accordance with previous examples. A first component is arranged in position. A second component is arranged in end-to-end relationship with the first and installed in position. The ducts and channels are substantially in register. An elongate drainage system is thereby installed having a continuous channel along the length of the system as well as regularly spaced slots.

In one example, the components are arranged so that an end having a slot of one of the components is arranged to face a planar end of an adjacent component. In an alternative example, the components are arranged so that an end having a slot of one of the components is arranged to face an end having a slot of an adjacent component. In a further example, each end of a component includes a slot so that each end also faces an end having a slot of an adjacent component.

In one example, the adjacent components are arranged to have a constant separation so that the installed system has a continuous and substantially co-axial duct. Alternatively or additionally, one or more adjacent components may be arranged to have non parallel end faces so that a curve is introduced into the system.

According to a further example there is therefore provided a drainage system comprising a plurality of adjacent drainage components. Here, each adjacent drainage component is in accordance with previous examples and the drainage system is installed in accordance with the previous exemplary methods.

According to another aspect there is provided a single-piece kerb unit that includes a drainage component. The single piece kerb unit is suitable for use as a kerb or edging and comprises a duct extending through the drainage component from one end face to another end face; and a slot extending between a face of the drainage component and the duct. In this aspect, the kerb unit, in use, forms part of a drainage system. In particular, the kerb unit is arranged as a barrier at an end of a surface to be drained. Here, the kerb unit includes an upper portion having at least one side face that is intended to be raised from the surrounding surface to form a step. For instance, the kerb unit may be arranged to form a kerb between a car park having a drainage system and a raised footpath or a footpath and raised landscaping area, or other configurations of two areas separated by a step. Suitably, the kerb unit is particularly suitable for use as an edging to the previous examples.

In an example of the kerb unit, the slot extends between the duct and said side face of the upper portion. The slot may also extend to an upper face, wherein the upper face is generally parallel to the plane of the surface finish. In an example, the upper portion is chamfered so that a part of the side surface extends at an angle relative to the plane of the surface finish. Typically the chamfer may be defined by national standards such as BS EN 1340:2003, which defines an angle of around 45° for a half battered or between around 12.5° and 15° for a splayed kerb.

The slot may be formed in each of the end faces. Conveniently, a first drainage component may be butted against a second drainage component in a drainage system such that slots of each drainage component are joined to form a larger slot. A uniform appearance and increased drainage capacity may be obtained thereby.

The slot may have sides, wherein at least one of the sides extends perpendicularly relative to the upper face. The lateral end face may extend between the one end face and the other end face. The upper face and the lateral end face may be joined at a chamfered portion. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which:

Figure 1 is a perspective view of a drainage component according to the prior art;

Figure 2 is a perspective view of a drainage component according to an exemplary embodiment;

Figure 3 is a perspective view of a drain formed using the drainage components of Figure 2;

Figure 4 is a perspective view of a drainage component according to a further exemplary embodiment;

Figure 5 is an end view of Figure 4;

Figure 6 is a perspective view of a drain formed using the drainage components of Figure 4;

Figure 7 is a perspective view of two alternative drainage component according to further exemplary embodiments;

Figure 8 is a perspective view of a drains formed using the drainage components of Figure 7;

Figure 9 shows the process steps of installing a drainage system;

Figure 10 shows a further exemplary embodiment of a drainage component; and

Figure 1 1 shows another exemplary embodiment of a drainage component.

Referring to Figure 2 a drainage component (100) is shown having a duct (1 10) and a slot (130). The drainage component (100) is used to form a drainage system as shown in Figure 9. Here, a plurality of drainage components are installed in end-to-end relationship within a trench. An upper surface (101) of the drainage component is installed in a desired location, such as level with a surrounding area or, more usually, slightly below to allow for positive drainage. Typically, the drainage component is bedded in concrete. The haunched components are therefore secured in place. The trench is backfilled and the surrounding area paved or otherwise finished. The completed drainage system provides a longitudinal drain formed from the aligned ducts of each component. The longitudinal drain is underground and arranged to carry water for appropriate collection or disposal as is known in the art. For instance, the components are laid on an incline. It will be appreciated that apart from the opportunities created by the differences highlighted herein and in particular the size of the components, the components can be installed as is known in the art.

As will be understood, the components are butted against each other. Typically in a linear arrangement having uniform gap distance, but curved arrangements can be achieved with wedge shaped gaps between adjacent components or wedge shaped components. For instance, the end faces of the components may be arranged to be angled. One or both ends might be angled. Whilst the ends may be angled in opposite directions so as to be converging, the angled end faces may remain parallel. For instance the top face of the component may form a parallelogram. Here, a straight drainage system can be achieved by rotating alternate components, or a curve introduced by arranging adjacent components in the same orientation. Sealant may be applied between the components in order to maintain water within the drain or alternatively the joints may naturally silt up with sediment and seal. It will also be appreciated that although the component is herein described as being substantially geometric in shape, such as a cuboid, other shapes are envisaged, for instance rather than the upper surfaces being substantially square, it may be rectangular, or curved or complex. Furthermore, although the components described herein are for use in a linear arrangement, with the duct running co-axially between two opposed end faces, joint components where the duct includes an elbow or more than two apertures to allow or '+' or input/output egresses are also envisaged.

The components described herein are single piece. Suitably, the components are moulded or cast. Here, a material is flowed into a mould. Dependant on the material, the component is set or cured either partially or fully within the mould before de-moulding to produce the finalised product. The single piece components may be moulded according any known method and the component may be moulded in any orientation, for instance with the base of the mould being the sides, end top face or bottom face as appropriate. However, in the exemplary embodiments, the base of the mould is envisaged as being the bottom face of the component. When the component is moulded with the duct across the horizontal plane, the duct is formed via a removable core. However, because of the arrangement of the slot and channel it is not necessary to remove further mould parts, thereby simplifying the mould and moulding process. Although numerous materials known in the art may be used to form the drainage components, a concrete with a cementitious or polymer binder is usually used in similar products and is envisaged to be the prime material for industrial use. The product is designed to be easily demoulded as well as to ensure correct compaction of the material as the mould is filled. With this in mind, although the duct is shown in the exemplary embodiments as being substantially cylindrical in shape with a substantially constant cross section having a circular profile, other shapes are envisaged. For instance, an inverted tear drop shaped profile (as shown in Figure 10), or oval profile to the duct has been found to aid material flow in the mould and subsequent compaction of the concrete material when moulding the product with the top face at the bottom of the mould.. The inverted tear-drop profile has also been found to improve flow velocities within the duct at low flow volumes.

Advantageously, the component can be formed from the same material as the surrounding surface. For instance, the components can be generally arranged to have the same size, shape, and appearance of a block paving module. Therefore, the handling of the components, laying methods and appearance can complement the block paving industry.

Referring back to Figure 2, the channel is shown as extending parallel to the duct and from one end face to the other. This is consistent in the exemplary embodiments and the channel (120) remains closed to the duct except via the slot (130). Because the channel is not open to the duct except via the slot formed in the end face(s), it is not necessary to mould closed apertures. In Figure 2, the channel is shown as a single channel formed along an edge of the component. Here, the channel is open to an edge, both ends and top of the mould. However, the channel (1 10) may be formed from one or more discrete channels. Furthermore, each discrete channel may be formed along an edge of the component or in the top surface spaced from an edge. For instance, referring to Figure 4, the channel is formed from two discrete channels (120a and 120b). Here each discrete channel is formed along a respective edge of the component. Furthermore, in Figure 7, embodiments showing two discrete channels (120a and 120b) and three discrete channels are formed, with each discrete channel spaced from an edge. Here, each discrete channel is open only to the top and ends of the mould. A combination of discrete edge channels and closed channels is also envisaged. The number and arrangement of the channels or each discrete channel forming the channel, is dependent on the requirements of the drainage system. For instance, the design of the channel is intended to have sufficient capacity to prevent water that runs towards the channel from flowing over the component, rather than into the duct via the channel and slot, particularly during heavy downpours. Whilst forming the channels along an edge of the component is easily moulded, forming the channels spaced from an edge retains a solid edge of the component against which the surrounding surface finish can be laid and also provides a preformed sealed channel which does not need secondary sealing.

The channel or each discrete channel forming the channel (120) of the exemplary embodiments has a substantially constant cross-sectional profile. In Figure 2, the cross- sectional profile is substantially rectangular. However, other cross-sectional shapes are envisaged, for instance to aid fluid flow, or to aid demoulding or compaction of the material. For instance, in Figure 7, the channels are show as having angled or arcuate side walls. Here, the channel has a narrower width as the channel extends away from the top surface.

The slot in the exemplary embodiments is formed in end faces of the component and extends from the top surface to the duct. The slot is open to the top surface and to the channel, and can therefore be the minimum width at the top surface to achieve connection with the channel. The slot is open to the duct sufficient to allow drainage, however, the slot is shown in the Figures to be open to the maximum width of the duct. As shown in Figure 2, the duct may have side walls (131 , 132) that are substantially parallel to the sides of the component. That is, the side walls may have a constant separation. The side walls in Figure 1 are shown extending perpendicularly to the end face. However, to also be open to the channel or each discrete channel, in Figure 2, the slot also includes an extension (133). However, as shown in Figure 4, one or both side walls may be angled relative to the side walls so as to communicate with the channel without the need for an extension. Furthermore, and as shown in Figure 4 particularly, the slot may be tapered so as to be wider at the top surface compared to the slot at the duct. Dependant on the design of the component and channel, the duct may also taper so as to be wider at the duct than the top surface in order to reduce the chances of blockage.

In the exemplary embodiments, the components are butted against adjacent components to form a longitudinal drain. Here, the slots provide regular and repeated drainage points. In the exemplary embodiments described herein, each component includes a slot on one end and a substantially planar other, opposed end. The end of one component including the slot would be arranged to abut against either a planar end of the adjacent component, in which case the slots would be pitched substantially at a length of the component, or an end of the adjacent component also including a slot, in which case the next component would be arranged with its planar end against the planar end and the double slots pitched approximately twice the length of each component. However, in alternative embodiments, the slot (130) is formed from first and second discrete slots in each end face of the component. Here the component would be reversible, and the components always laid with a slot of one component adjacent the slot of the other component. Advantageously, forming the slot in each end face allows the slots to be shallower. That is, to achieve an intended slot dimension, each discrete slot on the end faces only has to extend half the distance of the intended slot into the end face. This reduces compaction issues between slot and bottom of the mould, when a removable core is used.

Fig. 1 1 shows a further example of a single-piece drainage component (200). The drainage component (100) described with reference to Figs. 1 to 10 is arranged to form a barrier extending perpendicularly to a flow of surface water. By contrast, the kerb unit (200) is arranged to form a lateral barrier to surface water, for example as part of a surface water drainage system. Conveniently, the kerb unit (200) is provided with an inlet for removal of the surface water. Accordingly, many features are similar to the drainage component (100) described above and a detailed description thereof is omitted.

The kerb unit (200) may form part of a kerb or a step. In one example, the kerb unit (200) is arranged to bridge a vertical distance between a street surface and a raised footpath, but other configurations are envisaged. Suitably though, the kerb unit is intended to extend between two surfaces of different elevations.

The kerb unit (200) has a top surface (201). In some examples, the top surface is arranged to sit flush with the raised surface to one side.

The kerb unit (200) has a lateral side face (202). The lateral side face may in use face the surface to be drained, and at least a portion of the lateral side face may be exposed. That is the kerb unit has an upper portion configured to be installed raised from a surface on one side of the kerb unit, wherein a side face of the upper portion is raised from said surface. Conveniently, the lateral side face is arranged to form part of a barrier to a flow of surface water.

A duct (210) extends through the kerb unit (200). In this example, the duct (210) extends from a first end face to another end face of the drainage component (200).

A slot (230) is formed by the kerb unit (200). The slot is arranged to connect the top face (201) to the duct. That is, the slot may provide an inlet in the top face and flow communication to the duct. In some examples, the slot extends across the entire top face. In this example, the slot extends across part of the top face. The slot may extend substantially perpendicularly with respect to the duct, and may be arranged to extend in use substantially vertically through the drainage component.

The slot (230) extends between the duct and the side face of the upper portion. It is shown as an extension area (233). The extension is arranged to connect the lateral side face (202) to the duct (210). That is, the extension is arranged to provide an inlet in the lateral side face and flow communication to the duct. The slot also comprises a sidewall (231) in this example. The sidewall (231) delimits the slot at one side. In other examples, the sidewall (231) may be replaced or offset from the duct by another extension (233). In use, the kerb unit (200) is arranged to drain surface water running along or pressing against the lateral side surface. Conveniently, the drainage component has a drainage rate which increases with an increasing surface water level. That is, the slot (230) is configured to extend along a substantially vertical direction such that a larger proportion of the slot is utilised for drainage when the surface water level rises.

In some examples, the slot (230) is located between the first and second end faces of the kerb unit (200). In other examples, the slot (230) and its extension (233) are provided on either end face of the kerb unit (200). Conveniently, a component having a slot and a slot extension is easier to manufacture when the slot and the extension are provided on an end face. In this example, the slot (230) and its extension (233) are provided on both end faces of the kerb unit (200). Conveniently, such an arrangement means that the kerb unit (200) may form a larger slot when butted against another kerb unit (200) in a drainage system.

In this example, the kerb unit (200) is provided with a chamfer (240). That is, the top surface (201) and the lateral side face (202) are connected by a transition portion. Thereby the transition between the top face and the lateral side face may be smoothed and need not involve an edge.

There is provided an improved drainage component that can be easily moulded and used to form a drainage system that provides a surface drainage channel that extends across the length of the drainage system as well as discrete, regular drainage slots.

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims. Specifically, as a moulded product, corners may be rounded as is known in the art for mould relief and material flow within the mould. Where parts have been described as meeting at angles or faces being planar, this incorporates rounding of the edges, for example providing the otherwise sharp edge with a radius.