WO2016076715A1

WO2016076715A1 - Heliport illumination system, heliport

Info

Publication number: WO2016076715A1
Application number: PCT/NL2015/050786
Authority: WO
Inventors: Pieter Gerardus Goedknegt; Jan Willem DEÉ
Original assignee: Orga Holding BV
Current assignee: Orga Holding BV
Priority date: 2014-11-10
Filing date: 2015-11-10
Publication date: 2016-05-19
Anticipated expiration: 2017-05-10
Also published as: EP3218548A1; NL2013762B1

Abstract

Illumination system (1) for heliport comprising: at least one illumination unit (2) comprising at least one dome (4) of a light emitting element; and cabling (3) comprising a connecting element for connection to an illumination unit; further comprising a cover unit (5) for mounting over the at least one illumination unit and over at least the connecting element of the cabling, wherein the cover unit at an bottom side is provided with recesses for receiving the illumination unit and/or the connecting element of the cabling, and at an top side is provided with openings for allowing the at least one dome of the illumination unit extending there through, such that, when installed, multiple cover units are arranged to form a touchdown circle and/or a helipad H-area of the heliport.

Description

Title: Heliport illumination system, heliport

The invention relates to a heliport illumination system. A heliport deck typically may be illuminated at least during night to provide for a safe landing area for a helicopter. The landing area comprising a touchdown circle with a helicopter H inside of it, is usually marked with a yellow painted circle and white painted H and illuminated with flood lights positioned on sides of the landing area.

To improve visibility of the landing area for approaching helicopters, UK CAA issued a specification for a heliport lighting system. Several parties developed such a system comprising of illumination units with LED domes that can be mounted onto a helicopter deck.

In practice, it appears that the cabling and fixing fasteners for the illumination units which are laid onto the heliport deck may form an obstacle that could become loose and then, for example due to heavy winds induced by environmental conditions and/or helicopter rotor blades, may become an hazard for bystanders. Also, the illumination units and/or the cabling may form an obstacle on the deck due to their height. Obstacles on a heliport deck are considered disadvantageous, people may fall over it, a helicopter may tip over it, carriers for luggage and goods may catch behind it. Further, the conventional lighting system may involve a lot of

components thereby the installation time and/or testing time offshore may be increased. Also, maintenance costs may be relatively high.

Publication EP 0 748 979 discloses a lighting unit comprising a housing, LEDS provided in translucent caps located in apertures of the housing with the electrical connections to electrical cables contained in the housing. Once the LEDS have been connected to the cables, the housing is filled with a resin, such that the LEDS are encapsulated by the resin and the housing is completely waterproof. To provide a loom of the units, a channel is provided in a floor in which the cable with the housings fit. The channel is then closed at the upper side by a translucent cover. A drawback of the disclosed system is that the housings are filled with a resin that also encapsulates the electrical connections, which may impair the flexibility, maintenance and/or replaceability of the units.

Another drawback is that the housings are being fitted into a channel in the floor, which makes them difficult to use on a helideck.

Intermediate publication WO 2015/056200 discloses a chain of a set of lighting elements on an electrical conductor cable. A covering guard is positioned over a set of lighting elements. The chain provides for an electrical continuity and interruptions, such as connections, are absent in the cable.

An object of the invention is to provide an illumination system for a heliport that may obviate at least one of the above mentioned drawbacks while maintaining the advantages.

Thereto, an illumination system according to claim 1 is provided. By providing a cover unit covering the illumination unit and the cabling, as well as the cabling connectors, the number of parts exposed on the heliport deck may be reduced significantly. In fact, the cover units may then be exposed, and the domes protruding through the openings provided in the cover units for illuminating light. The cabling typically comprises electricity cabling, but may also comprise data cabling. The cabling typically comprises a protection sleeve to protect against e.g. environmental influences or impact etc.

The cabling may be connected between multiple illumination units, or may be connected between a remote unit, e.g. a power source or control unit, and an illumination unit. The cabling preferably comprises a connecting element at an end thereof to connect with the illumination unit. When the cabling connects between two illumination units, advantageously both ends are provided with a connecting element. Preferably, the cover unit covers the illumination unit as well as the connecting element of the cabling. In another embodiment, the cover unit may cover the at least one illumination unit, the connecting element and part of the cabling.

By providing connecting elements between the cabling and the illumination units, flexibility in use may be provided. Also installation and/or maintenance and/or repair may be more easy. Instead of a bulky chain with a number of sets of lighting elements already provided thereon, the individual components, such as cabling, illumination units and/or covers may be transported individually to the helicopter deck. Then, on the helicopter deck, the cabling may be laid and the illumination units can be connected thereto. The cover unit may then be positioned over the illumination unit and connected to the helideck. This allows for a flexibility in installation, depending on the configuration required, helipad H or touchdown circle, the cabling and the illumination units and cover units can be installed on the helideck. Also, for maintenance and/or repair, providing a connecting element may be advantageous for repairing for example a failed illumination unit. Then, the failed illumination unit can be removed and replaced by another illumination unit by simply de-connecting the failed illumination unit from the cabling and re-connecting to other illumination unit to the cabhng. Also, the absence of a channel in which the cabling and illumination units and cover units need to be placed is advantageous for installation, maintenance and repair on the helideck. Further, the absence of any resin the cover unit is advantageous as the cover unit can be a replaceable separate component which allows relatively easy installation, maintenance and/or repair. The cabling, illumination units and cover units can be mounted onto the helideck and no structural works on or in the helideck would be required that would impair the structure and/or strength of the helideck.

The connecting element may be a connector, e.g. a plug, or may be an eye at the end of the cable. Many variants are possible. The connecting element is configured to connect with the illumination unit to make an electrical connection with the illumination unit so electrical power can be transmitted to the illumination unit.

By providing at least one recess at a bottom side of the cover unit, the cover unit can be made sufficiently light as to facilitate the ease of handling by personnel e.g. during installation. The cover unit may be provided in various configuration, e.g. the cover unit can be configured having a hollow shape with openings in its upper side for receiving the domes of the light emitting elements. The cabling and/or connecting elements can then be received in the recess forming hollow space below the upper side of the cover unit.

In an embodiment, the cover units are arranged on the heliport deck adjacent to each other to provide for example for an uninterrupted touchdown circle. For example, in an embodiment, end surfaces of the cover units may abut against each other. By positioning the cover units adjacent each other, preferably abutting against each other, an uninterrupted upper surface may be obtained. In an embodiment, the distance between adjacent cover units may be as small as possible, preferably approximately 1 cm or less, as to provide for an approximately uninterrupted upper surface between adjacent cover units. When providing multiple cover units adjacent each other, preferably abutting each other, whole of the cabling between the subsequent illumination units may covered as well, thereby reducing the number of exposed parts on the heliport deck.

In an embodiment, the cover units may positioned at a distance from each other, with the cabling exposed inbetween. This may for example be the case for the touchdown circle. The cover unit then may cover the at least one illumination unit and the connection of the cabling thereto.

Advantageously, the cover unit and the at least one illumination unit may be assembled in a controlled environment, e.g. in a factory or an assembly hall or a yard. By pre-assembling the at least one illumination unit and/or the cabling to the cover unit, testing may be done in a controlled environment as well. Thus, the installation time and/or testing time on site and/or offshore may be reduced, thereby reducing installation costs, also faults or mistakes during installation may be reduced.

The cover unit may be manufactured from a metal material such as steel or a plastic material. For example, the cover unit may be

manufactured from steel, or a reinforced plastic material, etc. although many materials may be used. Also, the cover unit may be made by any suitable manufacturing method such as for example casting or moulding or deep drawing or thermoforming, injection moulding etc., thereby the recesses for receiving the one or more illumination units may be made in the cover unit during manufacturing. Also, by for example moulding or deep drawing the cover unit, the upper side of the cover unit may have a non-flat shape. When manufacturing the cover unit by e.g moulding or injection moulding, a mould may be provided. When manufacturing the cover unit by a forming process, such as deep drawing or thermoforming, a starting material may be provided, e.g. a plate, which then can be formed to the determined shape of the cover unit

Such a cover unit may for example be used when an interrupted surface may be provided on the heliport deck covering the at least one illumination unit and the connecting element of the cabling, with or without covering the cabling between subsequent cover units. For example, by providing a casted or thermoformed cover unit the upper side of the cover unit may be made rounded such as to reduce the obstacle height and/or edges. Instead of a metal cover unit, the cover unit may also be

manufactured from plastics, e.g. by injection moulding. By metal moulding or plastic injection moulding various shapes and forms of the cover unit may be possible, also various finishings of the surface, such as roughening, may be possible. In an embodiment, the illumination units of the helipad H-shape are covered by the cover units, thereby covering the cabling as well. Thus, a relatively smooth helipad H upper surface may be provided.

The invention further relates to a heliport comprising an illumination system comprising illumination units and cover units, to a set of an illumination unit, cabling and a cover unit.

Further advantageous embodiments are in the subclaims.

The invention further relates to a heliport comprising an illumination system and to a kit of parts.

The invention will further be elucidated on the basis of exemplary embodiments which are represented in the drawings. The exemplary embodiments are given by way of non-limitative illustration of the invention.

In the drawings:

Figure 1 shows a schematic cross-sectional view in transverse direction of an illumination system;

Figure 2 shows a schematic perspective view of the illumination system of figure 1;

Figure 3 shows a schematic bottom view of the illumination system of figure 1;

Figure 4 shows a schematic cross-sectional view in longitudinal direction of the illumination system of figure 1;

Figure 5 shows a schematic perspective view of another embodiment of the illumination system; and

Figure 6 shows a schematic bottom view of the embodiment of figure 5.

Figure 7 shows a schematic perspective detail view of a heliport provided with a configuration of the illumination system in a first embodiment;

Figure 8 shows a top view of the embodiment of figure 7; and Figure 9shows a schematic perspective view of a heliport provided with a configuration of the illumination system in a second embodiment.

It is noted that the figures are only schematic representations of embodiments of the invention that are given by way of non-hmiting example. In the figures, the same or corresponding parts are designated with the same reference numerals.

Figure 1 shows a cross-section of an illumination system 1 according to the invention. The illumination system 1 comprises at least one illumination unit 2 and cabling 3 to connect thereto. The cabling 3 is provided with a connecting element for connection with the illumination unit 2.

The illumination unit 2 comprises at least one light emitting element, preferably an LED. The light emitting element is for reasons of simplicity not shown here. The light emitting element is protected by a dome 4. The dome 4 is transparent and/or translucent to allow hght rays of the light emitting element to pass through it. The domes 4 typically extend somewhat above the illumination unit to 2 also allow hght rays to emit from the dome 4 at a small angle, for example at an angle of approximately 0 degrees or at an angle between approximately 0 degrees and

approximately 5 degrees depending on the requirements.

The cabling 3 usually may be electricity cabling, for providing electricity power to the light emitting elements. The cabling 3 may also comprise data cabling for transmitting data signals e.g. to/from the light emitting elements, but in other embodiments sensors may be provided on the deck and/or on the illumination units and as such data may be transmitted. The cabling advantageously comprises a protection sleeve to protect against e.g. environmental influences or impact etc.

Further, the illumination system 1 comprises a cover unit 5. The cover unit 5 is arranged for mounting over the illumination unit 2 and over at least the connecting element of the cabling 3 as to protect the illumination unit 2 and at least the connecting element of the cabling 3. Advantageously, the cover unit 5 extends at least over the illumination unit 2 in longitudinal direction of the illumination unit 2. In other embodiments, the cover unit 5 may be as large as to cover multiple illumination units 2. As such, the number of different parts exposed on the helideck may be reduced, since only the cover unit 5 is now exposed while the cabling 3, or at least the connecting element, and the illumination unit 2 are shielded by the cover unit 5. In an embodiment, also the cabling 3 may be protected by the cover unit 5, so a risk of e.g. the cabling coming loose or e.g. stumbling over different parts may be reduced. In other embodiments, the cover unit 5 may cover at least one illumination unit and a connecting element 8 of the cabling 3 to the illumination unit 2. The connecting element 8 may be embodied as an eye at the end of the cable 3 that may be fit in or to a hook of the illumination unit 2 to form an electrical connection. The connecting element 8 may alternatively be embodied as a plug that may fit into a socket of the illumination unit 2. The connecting element 8 may be embodied as any type of connector that may fit to illumination unit 2 to obtain an electrical connection to transmit power to the illumination unit 2. The wordings 'connector' and 'connecting element' are used exchangeable.

The cover unit 5 is at a top side 5a provided with at least one opening 6 to allow the dome 4 to pass through it and thus to extend above the top side 5a of the cover unit 5 such that light rays may be emitted at small angles. In an embodiment, there is a single dome 4 fitting into a single opening 6, as for example shown in the embodiment of figure 2. In other embodiments, multiple domes 4 may fit into a single opening 6.

As shown in the longitudinal cross-section of figure 4, the illumination unit 2 is here provided with four domes 4, but may be provided with a single dome 4 or with multiple domes 4. The embodiment shown is a mere example, and the number of domes shown is exemplary as well, a different number of domes may be provided. The height A of the cover unit 5 is sufficient to cover the height of the illumination unit 2 and of the cabling 3. Advantageously, the height B of the recess 7a is sufficient to receive the illumination unit 2. In this embodiment, the cover unit 5 may receive a single illumination unit 2, however in other embodiments, the cover unit 5 may receive multiple illumination units, for example two or three

illumination units arranged adjacent each other.

The cover unit 5 may have various shapes, for example triangular or with curved sides or circular segment etc. Many shapes are possible. Also, the edges may have various configurations, e.g. chamfered or curved or inclined or grooved etc. Also, depending on the manufacturing method, the top side 5a may have a more "organic" shape, such as in the embodiment shown in figure 1, or may be rounded or any other cross- sectional shape. Many variants thereof are possible.

The embodiment shown in figure 2 may be manufactured from various materials, for example the cover unit may be manufactured from a metal material such as steel or from a plastic material. Many variants are possible. The cover unit may be manufactured as to cover the at least one illumination unit and the cabling or may be manufactured as to cover the at least one illumination unit and the connector of the cabling, while leaving cabling partially uncovered.

At a bottom side 5b, the cover unit 5 may be provided with at least one recess 7 for receiving the illumination unit 2 and/or the cabling 3. By providing the recesses 7, the cover unit 5 may be extending over the cabling 3 and/or the illumination unit 2 sideways as well. So, the cabling 3 and/or the illumination unit 2 may protected in a height direction by the cover unit.

In the bottom view of figure 3 there is shown a cover unit 5 provided with a central recess 7a for receiving the illumination unit 2, side recesses 7b for receiving a connector 8 of the cabling 3 and channel recesses 7c for receiving the cabling 3. In this embodiment the side recesses 7b are positioned at a longitudinal side of the central recess 7a, but may of course also be provided at an end side of the central recess 7a. Also, here, there are two side recesses 7b provided for two connectors 8, i.e. for the connector 8 of the cabling 3 entering the illumination unit 2 and for the connector 8 leaving the illumination unit 2. In other embodiments, there may be a single connector 8 provided for entering and leaving of the cabling to/from the illumination unit. Many variants are possible.

For installation purposes, the cover unit 5 may be provided with fixation elements to fixate the cover unit 5 to a heliport deck. The fixation elements are not shown in the figures, but may be provided by well known means, such as a hole through which a screw can be inserted, or clamps or rivets that can be fixed onto the deck etc. The fixation elements may be provided along the longitudinal sides of the cover unit, e.g. on sides 5d, or on the short sides. The sides 5d may be provided as flanges from the cover unit in which the fixation elements can be arranged. The fixation elements may also be provided at any other position of the cover unit 5.

For installation on the heliport deck, first the illumination unit 2 and the cabling 3 are mounted into the cover unit 5 to form the illumination system 1. Then the illumination system 1 may be installed on to the deck. Cabling between illumination systems 1 may be connected to the

illumination systems during the installation thereof onto the deck, for example by first installing the cabling onto the deck and fitting the illumination unit over it, or by first installing the illumination units adjacent each other and, during installation, temporarily lifting the cover unit to fit the cabling thereto. Advantageously, the illumination units 2 and the cabling 3 may be mounted to the cover units 5 beforehand, for example remote from the installation site. The assembly of the illumination system 1 may thus be done in a controlled environment, e.g. in a factory, or on a yard. For example, when the illumination system is to be installed offshore, the pre-assembly of the illumination units in a controlled environment may be advantageous and may reduce the risk on mistakes, as well as may reduce the installation time on site, etc. Thus, the illumination system 1 may equally well be used for new built decks as for refitting decks already provided with illumination units and cabling.

In other embodiments, the illumination unit 2 and the cabling 3 may be installed onto the deck first and may then be connected to each other. Thereafter, the cover unit 5 may be mounted over the already installed cabling 3 and the illumination units 2. In other embodiments, the cabling may be integrated with the cover unit 5 as well. The cover unit 5 may then be provided with a coupling element arranged for coupling to a coupling element of an adjacent cover unit, thereby providing an integrated system for mounting on the deck. Such a coupling elements may be e.g. a pin-hole coupling, or a click-coupling or a plug/socket coupling etc.

In the embodiment of figures 1 - 4, the top side 5a here has a relatively "organic" shape and may form a more rounded upper surface 5c. The recess 7 may comprise a central recess 7a in which the illumination unit 2 may be positioned. The central recess 7a may extend in longitudinal direction over the length of the cover unit 5. The recess 7 may comprise side recesses 7b arranged at a side of the central recess 7a, e.g. to provide for space for the connecting element 8 to connect to the illumination unit 2.

Depending on the configuration of the connection between the cabling 3 and the illumination unit 2, there may be a single side recess 7b provided, or the side recess 7b may be provided at another side of the central recess 7a, e.g. the short side. In another embodiment, the side recesses 7b may be obviated, as shown in figures 5 and 6. The upper surface 5c of cover unit 5 may then have a more simple or more rounded shape. Many variants are possible.

In the embodiments of figures 1 - 4 or figures 5 - 6, also a flange 5d is provided to allow fixation elements to fix the cover unit 5 to an underground through the flanges 5d. In other embodiments, a flange may be obviated, or may be provided at a short side of the cover unit, or may be embodied as a lip through which the fixation elements may be positioned. In an other embodiment, the fixation elements may be positioned at any location of the cover unit 5 to mount the cover unit 5 on an underground. The fixation elements may be screws or bolts, or clamps or hooks or pins to fit into a corresponding holding element of the underground to fixedly mount the cover unit. Many variants of the fixation elements are possible.

The cover unit 5 may be manufactured e.g. by metal moulding or plastic injection moulding, or deepdrawing or thermoforming etc. and/or may be manufactured from steel, or plastics, or any other suitable material. By using such a manufacturing method, the amount of material may further be reduced and/or the cover unit may become lighter, which may facilitate assembly and/or installation. The shape of the cover unit 5 may then become more "organic" as in that it can be curved or rounded or have otherwise variations in shape.

Figure 7 shows a first embodiment of an arrangement of illumination systems 1 onto a heliport deck. The illumination systems 1 are positioned with their end sides adjacent each other to form an

approximately uninterrupted touchdown circle 9. The touchdown circle 9 may be uninterrupted as in that an upper surface of the touch down circle 9, formed by an upper surface 5c of the cover units 5 may be approximately continuously. By positioning the illumination systems 1 adjacent each other, preferably with the end sides abutting against each other, the gap between adjacent illumination systems 1 may be minimal thus providing for an approximately smooth and/or approximately uninterrupted upper surface. The touchdown circle 9 may now circumferentially have approximately the same height A above the deck and may have approximately the same width over the circumference. So, the touchdown circle 9 has now more or less similar dimensions over the circumference, thereby increasing the

predictability of the presence of the touchdown circle on the deck, thereby reducing hazardous situations. To configure a touchdown circle 9, the cover units 5 may have a ring-segment shape.

The cover units 5 may be mounted abutting against each other, for example their end sides may be positioned against each other upon installation on the deck, to provide for an approximately uninterrupted touchdown circle and/or helipad H. In other embodiments, the cover unit 5 may be provided with grooved end sides, which may cooperate with the grooved ends of an adjacent cover unit, for example to provide a mesh/groove connection, or a click-connection to easily connect multiple cover units to each other. In other embodiments, the cover units may only be mounted at the positions where light emitting units may be required. So, an interrupted touchdown circle and/or helipad H may be provided, exposing the cabling between the subsequent light emitting units.

Also, with respect to the helipad H area 10, cover units 5 may be positioned adjacent each other to form a H-shape, as for example in Figure 9, or to form a rectangular area comprising the H, as shown in figure 7, or to form a circular area comprising the H, etc. Here too, many variants are possible of coupling the cover units 5 to each other, with their end sides and/or with longitudinal sides, abutting and/or coupling etc. The cover units 5 used for the helipad H may be provided with openings 6 in line, similar to the cover units used for the touchdown circle, or may be provided with openings 6 configured in a partial H-form, as shown in figure 7.

Alternatively and/or additionally, a cover unit comprising a single opening 6 for a single dome 4 may be used, providing flexibility in positioning the cover units. Here too, many variants are possible.

Figure 8 shows illuminations systems 1 mounted onto a heliport deck forming an uninterrupted touchdown circle 9 and a rectangular helipad H-area 10. In this embodiment, both the touchdown circle 9 and the helipad H-area 10 are at an height A with respect to the deck surface. Figure 9 shows a further embodiment of an illumination system 1 with an helipad H 10 in the H-shape. The touchdown circle 9 is here also shown as an uninterrupted touchdown circle 9, but in alternative

embodiments may be interrupted. For example, only cover units 5 may be provided to cover the illumination units 2, but to keep the cabhng 3 between adjacent illumination units uncovered. For such a cover unit a more organic shape, as for example shown in figure 6 and figure 7, may be provided. This may result in a lower built-up height, while maintaining the advantage of pre-assembly with the illumination unit, less components, etc. Alternatively, also with a more "organic" shaped cover unit, panel units may be used to cover the cabling having the same or similar shape as the cover unit.

A further aspect is a method for manufacturing a metal cover unit for use in a system; comprising providing a mould of the cover unit;

casting the metal in the provided mould. Another aspect is a method for manufacturing a metal cover unit for use in a system; comprising providing shaping tool of the cover unit; deep drawing the metal or chemically or mechanically removing redundant material, in the provided tool. As another aspect there is provided a method for manufacturing a plastic cover unit for use in a system; comprising providing a mould of the cover unit; injection moulding the plastic to the provided mould. In another aspect there is provided a method for manufacturing a plastic cover unit for use in a system; comprising providing a tool of the cover unit; thermoforming the plastic to the provided mould.

For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include

embodiments having combinations of all or some of the features described.

Many variants will be apparent to the person skilled in the art. All variants are understood to be comprised within the scope of the invention defined in the following claims.

Claims

1. Illumination system for a heliport comprising: at least one illumination unit comprising at least one dome of a light emitting element; and cabling comprising a connecting element for connection to an

illumination unit; further comprising a cover unit for mounting over the at least one illumination unit and over at least the connecting element of the cabling, wherein the cover unit at a bottom side is provided with at least one recess for receiving the illumination unit and/or the connecting element of the cabling, and at a top side is provided with at least one opening for allowing the at least one dome of the illumination unit extending there through, such that, when installed, multiple cover units are arranged to form a touchdown circle and/or a helipad H-area of the heliport.

2. Illumination system according to claim 1, wherein the multiple cover units are arranged to provide an uninterrupted touchdown circle and/or an uninterrupted helipad H-area.

3. Illumination system according to any of the preceding claims, wherein the helipad H-area is provided as an uninterrupted H-shape or as an uninterrupted rectangular area comprising the Ή".

4. Illumination system according to any one of the preceding claims, wherein the cover units are arranged to abut each other.

5. Illumination system according to any one of the preceding claims, wherein the cover unit is arranged for fixating to a heliport deck.

6. Illumination system according to claim 5, wherein the cover unit comprises a flange for fixation on the heliport deck.

7. Illumination system according to any one of the preceding claims, wherein the cover unit is manufactured from a metal material or a plastic material.

8. Heliport comprising a heliport deck to which an illumination system according to any one of the claims 1 - 7 is mounted.

9. Heliport according to claim 8, wherein the helipad H is part of a rectangular helipad-area provided with illumination units forming the Ή" and cover units covering at least the connecting elements of the cabling and the illumination units.

10. Heliport according to claim 8 or 9, wherein the touchdown circle is provided by illumination units in a circle and cabling connected

therebetween, further comprising cover units covering the illumination units and the cabling as to arrange the cover units to form a touchdown circle.

11. Heliport according to any one of claims 8 - 10, wherein the illumination units and cabling are arranged on the deck and the cover units are fixated to the deck.

12. Kit of parts comprising of at least one illumination unit having at least one light emitting element, cabling having at least one connecting element and at least one cover unit arranged for receiving at least the connecting element of the cabling and the illumination unit at a bottom side thereof.

13. Method for manufacturing a metal or plastic cover unit for use in a system according to claim 1; comprising

- providing a mould of the cover unit;

- casting the material in the provided mould.

14. Method for manufacturing a metal or plastic cover unit for use in a system according to claim 1; comprising

- providing a starting material for the cover unit;

- forming the starting material, e.g. by deep drawing or thermoforming or removing redundant material, to the determined cover unit.