WO2013024287A1

WO2013024287A1 - Lighting

Info

Publication number: WO2013024287A1
Application number: PCT/GB2012/051987
Authority: WO
Inventors: Paul Atkinson; Jonathan Anderson; Jon Laws
Original assignee: Atkinson Design Associates Ltd.
Priority date: 2011-08-18
Filing date: 2012-08-15
Publication date: 2013-02-21
Also published as: GB2493757B; GB201114200D0; GB2493757A

Abstract

A lighting assembly (10) is provided that comprises a lighting element and a light transmittant spiral element (18). The spiral element (18) has a spiral recess therein for receiving the lighting element. The spiral element (18) is configured with a varying cross section along its length such that, under the influence of gravity, extension of the centre of the spiral element in an upwards vertical direction substantially regularly spaces the coils from one another in the vertical direction.

Description

Lighting

The present invention relates to lighting assembly, in particular to ornamental lighting assemblies.

Ornamental lighting assemblies are known in the art, in particular spiral lighting that replicates a tree, in particular a conical Christmas tree. Such existing designs traditionally include a rigid framework around which a flexible rope light, having no structural rigidity of its own, is wound and secured.

There are a number of problems with these types of light. The framework produces an undesirable visual effect during the daytime and tends to block line of sight to the opposite side of the spiral during the night time. Further more these types of lighting assembly are generally fairly bulky and require a large amount of storage space.

It is the object of the present invention to provide an improved lighting assembly.

According to a first aspect of the present invention there is provided a lighting assembly comprising: a lighting element; and a light transmittant spiral element having a spiral recess therein for receiving the lighting element; wherein the spiral element is configured with a varying cross section along its length such that, under the influence of gravity, extension of the centre of the spiral element in an upwards vertical direction substantially regularly spaces the coils from one another in the vertical direction. Preferably extension of the centre of the spiral element in an upwards vertical direction substantially forms a conic helix.

As used herein the term spiral is used to encompass not only a regular spiral, i.e. a circular spiral, but should also be interpreted to include spirals of other cross sectional shape, for example square or hexagonal spirals having straight sides of that increase in length from the centre of the spiral to the outside of the spiral, and the term conic helix will be interpreted to include extended polygonal spirals wherein the shape formed by the side view of the extended spiral is a substantially straight sided triangle.

By varying the cross section along the length of the spiral the spiral can be self suspending in a conical helix such that the coils of the helix are substantially evenly spaced which produces an even lighting effect without the need for a supporting structure to maintain the coils in their desired substantially even spaced relation.

Preferably a spacing means is provided which is configured to support the centre of the spiral element in a position in which it is extended in said upwards vertical direction.

The lighting assembly may also comprise a base and wherein the outer end of the spiral is supported on the base and wherein the spacing means retained in the base. In this manner a self supporting light is provided which can be stood on any suitable surface and which apart from its central point is unsupported along its spiral.

The spiral element preferably comprises a centre section having a recess therein for receiving the spacing means. The base may have a recess therein for receiving the spacing means.

The spacing means preferably comprises a pole, which may separate into a number of shorter pole sections for storage. The cross sectional area of the spiral element preferably increases from its centre to its outer end. The width of the spiral element cross section may also increase from its centre to its outer end.

In one preferred arrangement the spiral element comprises a first inner section and a second outer section, and wherein the rate of increase in the width of the spiral is greater in the first section than in the second section

The cross section of the spiral element is preferably substantially oval in section. The lighting assembly may further comprise a cover element covering the recess thereby substantially enclosing the lighting element therein. Preferably the recess is provided in the underside of the spiral element and preferably the recess extends along the centre line of the spiral element. In a preferred arrangement the spacing between adjacent coils of the spiral is constant substantially along the length of the spiral element. Preferably the distance between centrelines of adjacent coils of the spiral decreases towards the centre of the spiral. In one preferred embodiment the light element comprises a light emitting filament, for example electroluminescent wire such as that sold by Olmec Advanced Materials Ltd, under the Surelight brand.

In another preferred embodiment the light element comprises a plurality of LEDs mounted at a substantially constant spacing on a flexible circuit board. Preferably the flexible circuit comprises a flexible spiral circuit board having a centre line that is matched with the centreline of the groove in the spiral element.

Preferably the groove comprises a stepped groove having a wide shallow section and a narrow deeper section centrally located within the shallow section. The deeper section may comprise a plurality of enlargements therein for receiving light emitting elements of the light element. The deeper section may further comprise a small curved groove along the centre line of its bottom surface for centrally locating an electroluminescent wire.

A plurality of opposing ribs may be provided on the inner surfaces of the groove to retain the cover.

In one preferred embodiment the spiral element comprises a tapered section joining the inner end of the spiral to the centre section.

There may be provided a plurality of raised circular ridges on the topside of the spiral element surrounding the LED locations. The spiral element may comprise a single plastics moulding. The injection points of the moulded material into the moulding bay may be located within the raised circular ridges.

In a preferred embodiment the spiral element has a downward rib extending on either side of the groove. According to a second aspect of the invention there is provided a method of manufacturing the spiral element of the lighting assembly of the first aspect of the invention, method comprising: providing an injection tool having a mould cavity for forming the spiral element therein; providing a feed manifold having a plurality of hot injection tips; providing a plurality of injection shut off valves associated with each injection tip; maintaining the manifold at an elevated temperature at which the polymer is maintained in a flowable state; sequentially operating the shut off valves so that the polymer flows into the mould cavity from the outside towards the centre of the spiral in a substantially continuous flow wherein as the flow of polymer reaches the next injection point the shut off valve associated with that injection point is opened, and the shut off valve associated with the previous injection point is closed.

Preferably the feed manifold has four arms, each substantially equally spaced, and each arm has two of said injection tips thereon. The manifold is preferably substantially cruciform.

The method may further comprise maintaining the full injection pressure for an extended time period after the mould cavity is full. Preferably the full injection cycle lasts approximately 5 seconds and the injection process maintains full injection back pressure for approximately 90 seconds to ensure the polymer is held under constant feed pressure.

The mould cavity may be configured for moulding a spiral element having a stepped groove having a wide shallow section and a narrow deeper section centrally located within the shallow section and wherein the deeper section comprises a plurality of enlargements therein, the method further comprising providing a plurality ejector pins located in a spiral arrangement and aligned with each of the enlargements. The method may also comprise providing an ejector assembly aligned with a centre of said spiral element.

Preferably the method further comprises providing water cooling means for said injection tool; after injection of the polymer, cooling said injection mould tool to solidify the polymer; and removing the spiral component from said mould cavity. In a preferred embodiment the polymer is polycarbonate and the manifold is maintained at 270° ± 5 °. Preferably cooling said injection mould tool comprises cooling the injection tool to reduce the temperature of the spiral element to 120° ± 5°. Specific embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 1 shows a light assembly in accordance with the invention; Figures 2 to 5 show the steps in the assembly of the light assembly of the invention;

Figure 6 shows a cross section through the base and spiral element of the invention in its unassembled state; Figure 7 shows a top view of the spiral element of the invention;

Figure 8 shows a bottom view of the spiral element of the invention;

Figure 9 shows a close up perspective view of a section of the bottom of the spiral element;

Figure 10 shows a close up perspective view of a the centre section of the top of the spiral element; Figure 1 1 shows a detail cross section through the spiral element; Figure 12 shows an exploded view of the lighting assembly; and Figure 13 shows a section view of the base showing the power/electrical connector.

Referring to Figure 1 a lighting assembly 10 of the invention is shown. The assembly comprises four main parts, a base 12, a supporting pole 14, a top piece 16 and a spiral element 18 which houses a lighting element (see Figure 12). The base 12 is provided with an electrical connection, not shown in this Figure, for connection to a source of electricity and the spiral lighting element will be housed in the spiral element 18 and connected to the source of electricity. The lighting element will extend along the length of the spiral element 18 so that when supplied with electrical power light will emit substantially along the length of the spiral element 18. The light may be admitted continuously along the length or intermittently i.e. at a series of discrete lighting points extending along the length of the spiral element 18. A supporting pole 14 is retained within the base 12 and extends vertically upwards therefrom. The upper end of the support 14 attaches to the centre of the spiral element 18 so that the centre of the spiral element 18 is extended vertically above the base and the spiral forms a conic helix extending from the top of the support 14 to the base 12. The top piece 16 is provided that essentially completes the end of the cone formed by the conic helix. The top piece 16 may be formed intricately with the centre of the spiral element 18 may be provided as a separate part, or may be omitted altogether.

It will be appreciated that the spiral element 18 made of a light transitional material so that light emitted from the lighting element 16 housed in the spiral element 18 can escape therefrom. As described above the spiral element 18 has a varying cross-section along its length that results in the forming of the conic helix when its centre point is extended vertically upwards. This is in contrast to the deformation behaviour of a regular spiral having a constant cross-section which is subject to very complex deformation forces when its centre point is extended. In particular the weight causing the deformation between each two adjacent coils varies along the length of the deformed spiral as towards the top of the spiral there is a greater weight that is supported by the coils beneath it than there is towards the bottom of the spiral. Furthermore, the increasing diameter of each ring of the spiral in effect makes the spiral more flexible as it reaches its lower turns as due to the increased diameter the stiffness is reduced.

The normal result when suspending a regular cross-section spiral from its centre point is the formation of a series of domed tight coils of the spiral towards the top, falling away to very large loose spirals lower down. By varying the cross section diameter the present invention ensures a substantially even spacing of the coils of the spirals from top to bottom when extended in this manner. Referring to Figures 2 to 5 the method of assembly of the lighting apparatus 10 is shown. The spiral element 18 is supplied inside, or packed flat attached to, the base 12 as shown in detail in Figure 6. The top piece 16 is pressed downwardly onto the centre of the spiral and attaches thereto by clips (omitted for clarity). The user then lifts the top piece 16 up extending the spiral element 18 from the base 12. The support 14 may comprise a plurality of support sections 14a to 14d which attach together to form a pole. The pole is inserted inside the spiral and the bottom end of it is received within a recess in the centre of the base 5 so it is supported therein in an upwardly extending manner. The upper end of the support 14 is then inserted into a recess in the underside of the centre of the spiral element 18 so that the centre of the spiral element 18 is supported on the support post 14 over the centre of the base 12 at a position vertically spaced therefrom. The changing cross-section of the spiral element 18, which affects its rigidity along its length, causes it to fall naturally to form a conic helix shape. Referring now to Figure 6, a cross-section is shown through the base 12 showing the spiral element 18 in its non-extended position.

The spiral element 18 comprises an outer rim 20 which clips onto the edge 22 of the base 12. It would be appreciated by the skilled person that the outer rim 20 may also attach to the base 12 by other conventional means e.g. plastics welding or adhesives, as is known in the art.

Preferably both the spiral element 18 and the base 12 are made of moulded plastics material, although it will be appreciated that the base 12 may be made of other materials e.g. it may be made of metal.

The base 12 is provided is with a centrally raised portion 24 having a recess 26 therein. The recess 26 has an internal diameter substantially corresponding to the external diameter of the support 14 so that when the end of the support 14 is received within the recess 26 it is retained therein in an upwardly extending manner. The spiral element 18 comprises a spiral consisting of a number of coils 28, the outer most of which is attached to the outer rim 20 at one end. The cross-section of the coils 28 is discussed in more detail in relation to Figure 1 1 , however as can be seen from Figure 6 the cross-sectional area of the sections of the spiral decrease towards the centre of the spiral, i.e. towards the upper end of the conic helix formed when the centre of the lighting assembly is extended as described hereinabove.

At the centre of the spiral element 18 is a centrepiece 30 which has a recess 32 therein. The recess 32 may be a through-hole as shown in Figure 6 or, alternatively may be a blind-hole opened in to its lower most side. In use the upper end of the support 14 is inserted into the recess 32 and engages therewith to support the centre of the spiral in a raised position. The centre of the spiral is provided with grooves into which the top piece 16, previously described, attaches.

Referring now to Figure 7 a plan view of the spiral element 18 is shown. As can be seen there is an outer rim 20 which extends in a circular fashion around the exterior of the spiral and a series of spiral coils extending from an attachment point 36 and spiralling inwardly therefrom to the centre of the spiral 30. As can be seen the coils of the spiral have a constant separation gap 38 between them along their length. As can also be seen the width of the coils 28 decreases from the exterior of the spiral towards the centre which results in the spiral getting tighter towards the centre, i.e. the centre point between adjacent coils of the spiral decreases from the exterior of the spiral towards the centre.

Located at substantially equally spaced distances along the length of the spiral are a number of raised circular ridges 40 on the upper side of the coils of the spiral element 18. When the spiral element 18 is lit by means of a plurality of discrete light emitting components these light emitting components are located centrally below these points. These ridges, although not essential the function of the invention, assist in distributing light from the light element. Furthermore, when this spiral element is manufactured as a single piece plastic moulding it is advantageous, due to the length of the spiral, to have a number of plastic injection points through which molten plastic is injected into the mould. These injection points are preferably located in the top side of the spiral within the boundaries of the raised ridges 40. As there is often an unevenness to plastic moulding at the point of injection, especially when hot tip injectors are being used, then by locating these injection points within the boundaries of the raised ridges 40 when the hand is run over the top of the spiral the raised ridges 40 prevent feeling of unevenness of these injection moulding points which would otherwise occur.

As can be seen, from approximately the last raised ridge 40 the spiral element curves inwardly at an increasing rate to a point at which it joins the centre section 30. This particular feature is described in more detail with reference to Figure 10 below. Referring now to Figures 8 and 9 the reverse, or lower, side of the spiral element 18 is described. The lower side of the spiral part of the spiral element 18 is provided with a recess 42 therein that extends along the centre line of the coils 28 of the spiral. Further details of the recess 42 are described in relation to Figure 1 1 below. At points corresponding to the locations of the raised ridges 40 shown in Figure 7 are a plurality of enlargements 44 located within the recess. The recess 42 comprises an outer section and an inner section 46 which is both deeper and narrower than the outer section and which is centrally located therein. The enlarged areas 44 are provided within the side walls of the lower section 46. In one particular lighting arrangement the lighting element not shown comprises a flat spiral shaped circuit board that locates within the outer part of the recess, and a plurality of surface mounted, or otherwise mounted, light emitting diodes (LEDs) that extend from the circuit board into the recesses 44. Although the LEDs are not necessarily sized greater than the width of the lower part 46 of the recess 42 the enlarged areas 44 allow for any manufacturing tolerances, in particular any intolerance in the system used to locate LEDs on the spiral surface of the circuit board during the manufacturing process.

Located around each enlarged section 44 are a plurality of ridges 48 which are substantially vertical ridges in the outer section of the recess. These ridges are sized to interfere with the sides of the circuit board when it is inserted into the recess so as to retain it. A lower cover, see Figure 1 1 , may also be provided to retain the circuit board in place and prevent access to it. These ridges may alternatively, or additionally, interfere with the sides of the cover so as to retain the cover plate in the groove thereby enclosing the circuit board therein. The groove maintains a constant cross-section from the outer turns of the spiral towards the centre irrespective of the changes in the cross-section of the spiral element 18. Referring now to Figure 10 the details of the centre 30 of the spiral and its attachment to the coils 28 of the spiral is described. After the last lighting position 50 the spiralled section increases the rate at which it spirals inwardly towards the centre element 30. Shortly after the last lighting point 50 the groove terminates in an end wall 52. There is then a transition section 54 that joins the grooved spiralled section 28 to a non-grooved attachment section 56. The transition section 54 is provided with two ramped sections 58 that increase the depth of the attachment section 56 to the depth required to enable the groove to commence. This method of connecting the centre section to the grooved section gives a strong solid connection but enables a reasonably high level of flexibility in this initial section so as to prevent a doming effect at the top of the conic helix which often occurs due to the high rigidity of the tight coils combined with the fact that the spiral joins the centre section 30 perpendicular to the direction of extension of the coil.

Referring now to Figure 1 1 a cross-section of the spiral, taken through the centre of one of the light positions, is shown. The section is substantially oval in shape and has a recess in its lower side. The recess comprises a first outer section 60 and a deeper narrower inner section 46. Two extended ridges 62 extend from the oval section on either side of the recess. The ridges 62 extend along the length of the coils of the spiral element and may vary in depth along the length to locally vary the rigidity of the cross-section. A circular ridge 40 is located on the upper face of the coil above each enlarged section 44 such that when a plurality of discrete light emitting elements, each located within the enlarged section 44, are provided, they are located below the ridges. A small curved recess 64 is provided in the base of the deeper recess section 46. An alternative arrangement to using the spiral circuit board described above alternative lighting may be used, e.g. electroluminescent wire such as available from Olmec Advanced Materials Ltd under their Surelight brand. When such a lighting product is used the curved recess 64 centrally locates it within the recess and it can be retained in place by inserting the bottom plate as shown in Figure 12.

The table below gives an example of a design created using finite element analysis to produce a light approximately 60cm high and having a vertical separation between adjacent coils of approximately 75mm, by varying the cross-sectional dimensions of the spiral section at each coil. Polycarbonate material was used for the spiral element and 87 light locations were evenly distributed along the length of the spiral.

Referring now to Figure 12, an exploded view of the light assembly is shown. As can be seen in this embodiment the support 14 consists of two tubular support poles 14a and 14b each of which are provided with inserts 66 at each end. The inserts 66 at the top end of the upper pole 14a and the lower end of pole 14b are received in the centre of the spiral element 18 and the recess in the base 12 respectively and inserts 66 at the upper end of the lower pole 14b and the lower end of the upper pole 14a are locatable in one another so as to join the two pole sections 14a and 14b together. The base 12 has a plurality of feet 68 attached to its lower surface. These feet may be rubber, silicon or any suitable material, ideally one which will prevent the base sliding over a hard surface. A light element is provided which comprises a spiral circuit board having a plurality of light emitting diodes located thereon. The circuit board is preferably cut from a sheet and the light emitting diodes are placed in their required locations thereon and electrical connections are made by known methods. The circuit board is inserted into the groove in the bottom surface of the spiral element 18 and a cover 72 is also inserted into the recess of the bottom of the spiral element 18 enclosing the light element 70 therein. The combined spiral element 18, light element 70 and cover 72 are then attached to the base 12. Although described in relation to a flexible circuit board with LED lights thereon alternative lighting elements may be provided in the recess in the spiral element 18 and enclosed therein via the cover 72. Referring to Figure 13 detail of the base 12 and the electrical connection for the lighting element is shown. A flat outer edge 22 of the base 12 has a hole 74 therein for receiving a cable from the lighting element 70 (not shown). The cable has a connector 76 attached thereto. The connector 76 and cable are passed trough the hole 74 into a recessed area 78 of the moulded base 12. A cover plate 80 is then fitted over the recessed area 78 to enclose the cable therein. The cover plate has a hole therein through which a part of the connector 76 is attached so that an electrical cable may be plugged into the connector 76 to power the lighting element. The connector 76 maybe a standard jack plug or any suitable electrical connector. The cable (not shown), passes from the connector 76 between the interior face 82 of the recess and the cover plate 80, and through the hole 74 where it joins the lighting element.

The spiral element is preferably made of polycarbonate and is manufactured as a single piece. An injection tool having a mould cavity for forming the spiral element therein is provided which has a heated feed manifold having a plurality of hot injection tips. Each hot tip has a shut off valve associated therewith so that the flow of the molten polymer can be controlled individually through each of the hot tips. The manifold is heated to 280°C to maintain the polymer polycarbonate therein in a flowable state.

The whole mould tool is also heated to maintain the polymer in a flowable state as it enters the mould cavity. The manifold is preferably substantially cruciform and the hot tips are located on the arms such that they are substantially evenly spaced along the length of the spiral element. For the moulding of the size in the example given eight hot tips are used, two on each manifold arm. Moulding is initiated by opening the shut off valve associated with the outermost shut off valve so that molten polymer flows into the mould tool. As the spiral element contains an outer circular rim the mould tool is operated such that the flow initially backfills from the injection point around the outer rim and then the polymer flows along the spiral from the outside towards the centre.

As the polymer advances to the next injection point the shut off valve for the first hot tip is closed and the shut off valve for the second hot tip is opened so that from that point the molten material enters the mould cavity via the second hot tip. The switch over from one hot tip to the next may take place when the flow is slightly before, is immediately under, or is slightly past the second hot tip, preferably the latter to ensure no occluded areas are present in the finished moulding.

The remaining shut off valves are operated sequentially as the mould cavity fills from the outside towards the centre of the spiral. Operating in this way reduces the maximum travel distance of polymer inside the mould cavity which assists in achieving a good moulded product with minimum shear occurring during the mould fill process.

Once the mould cavity is filled, full injection pressure is maintained for an extended time period after the mould cavity is full. In the present example the full injection cycle lasts 5 seconds and the injection process maintains full injection back pressure for 90 seconds to ensure the polymer is held under constant feed pressure.

The mould tool has a plurality of ejector pins located in a spiral arrangement and aligned with each of the enlargements in the groove. In the example 87 ejector pins are provided in a spiral arrangement aligned with each of the enlargements 44. A further ejector assembly is provided aligned with a centre of said spiral element. Ejector pins are also provided around the outer rim 20. Preferably the mould is water cooled so that after injection the tool temperature can be reduced to assist the solidification of the polycarbonate and once sufficiently solidified, preferably when the polymer temperature is 120°C the spiral element is removed from the mould cavity. As the spiral element is a free spiral moulded without any supporting structure it is not an easy structure to remove from the tool. To assist in the unloading of the spiral a robotic arm is provided that accepts the spiral directly from the tool and places it on a surface to finish cooling. The robotic arm maintains the spiral in its spiral configuration as it removes it from the tool.

It will be appreciated that the example given herein above is merely one dimensional arrangement of the invention which may be scaled up or down to produce a light spiral of required dimensions. Furthermore it will be appreciated that different cross sectional shapes may be used within the scope of the invention, for example the spiral section could have a rectangular cross section. It will also be appreciated that other light transmittant or partially light transmittant polymer materials apart form polycarbonate may be used, although the dimensional requirements of the coils of the spiral will be dependant upon the specific material as the deformation of the spiral any given point is dependant upon the mass of the coils below that point.

Claims

CLAIMS:

1 A lighting assembly comprising:

a lighting element; and

a light transmittant spiral element having a spiral recess therein for receiving the lighting element; wherein

the spiral element is configured with a varying cross section along its length such that, under the influence of gravity, extension of the centre of the spiral element in an upwards vertical direction substantially regularly spaces the coils from one another in the vertical direction.

2 The lighting assembly according to claim 1 wherein extension of the centre of the spiral element in an upwards vertical direction substantially forms a conic helix. 3 The lighting assembly according to claim 1or claim 2 further comprising a spacing means configured to support the centre of the spiral element in a position in which it is extended in said upwards vertical direction.

4 The lighting assembly according to claim 3 further comprising a base and wherein the outer end of the spiral is supported on the base and wherein the spacing means is retained in the base.

5 The lighting assembly according to claim 3 or claim 4 wherein the spiral element comprises a centre section having a recess therein for receiving the spacing means.

6 The lighting assembly according to claim 4 wherein the base has a recess therein for receiving the spacing means. 7 The lighting assembly according to any one of claims 3 to 6 wherein the spacing means comprises a pole.

8 The lighting assembly according to any one of the preceding claims wherein the cross sectional area of the spiral element increases from its centre to its outer end. 9 The lighting assembly according to claim 8 wherein the width of the spiral element cross section increases from its centre to its outer end

10 The lighting assembly according to claim 9 wherein the spiral element comprises a first inner section and a second outer section, and wherein the rate of increase in the width of the spiral is greater in the first section than in the second section

1 1 The lighting assembly according to any one of the preceding claims wherein the cross section of the spiral element is substantially oval in section.

12 The lighting assembly according to any one of the preceding claims further comprising a cover element covering the recess thereby substantially enclosing the lighting element therein.

13 The lighting assembly according to any one of the preceding claims wherein the recess is provided in the underside of the spiral element.

14 The lighting assembly according to any one of the preceding elements wherein the recess extends along the centre line of the spiral element.

15 The lighting assembly according to any previous claim wherein the spacing between adjacent coils of the unextended spiral is constant substantially along the length of the spiral element.

16 The lighting assembly according to any preceding claims wherein the light element comprises an electroluminescent wire.

17 The lighting assembly wherein the light element comprises a plurality of LEDs mounted at a substantially constant spacing on a flexible circuit board.

18 The lighting assembly according to claim 17 wherein the flexible circuit comprises a flexible spiral circuit board having a constant centre line with that of the groove in the spiral element. 19 The lighting assembly according to any preceding claim wherein the groove comprises a stepped groove having a wide shallow section and a narrow deeper section centrally located within the shallow section.

20 The lighting assembly according to claim 19 wherein the deeper section comprises a plurality of enlargements therein for receiving light emitting elements of the light element.

21 The lighting assembly according to claim 19 wherein the deeper section further comprises a small curved groove along the centre line of its bottom surface for centrally locating an electroluminescent wire.

22 The lighting assembly according to claim 12 wherein a plurality of opposing ribs are provided on the inner surfaces of the groove to retain the cover.

23 The lighting assembly according to claim 5 wherein the spiral element comprises a tapered section joining the inner end of the spiral to the centre section.

24 The lighting assembly according to claim 17 or claim 18 further comprising a plurality of raised circular ridges on the topside of the spiral element surrounding the LED locations.

25 The lighting assembly according to any one of the preceding claims wherein the spiral element comprises a single plastics moulding.

26 The lighting assembly according to claim 24 wherein the spiral element comprises a single plastics moulding and the injection points of the moulded material are located within the raised circular ridges.

27 The lighting assembly according to claim 13 wherein the spiral element has a downward rib extending on either side of the groove.

28 A method of manufacturing the spiral element of the lighting assembly of claim 1 , the method comprising: providing an injection tool having a mould cavity for forming the spiral element therein;

providing a feed manifold having a plurality of hot injection tips;

providing a plurality of injection shut off valves associated with each injection tip;

maintaining the manifold at an elevated temperature at which the polymer is maintained in a flowable state;

sequentially operating the shut off valves so that the polymer flows into the mould cavity from the outside towards the centre of the spiral in a substantially continuous flow wherein

as the flow of polymer reaches the next injection point the shut off valve associated with that injection point is opened, and the shut off valve associated with the previous injection point is closed. 29 The method according to claim 28 wherein the feed manifold has four arms, each substantially equally spaced, and each arm has two of said injection tips thereon.

30 The method according to claim 28 or 29 further comprising maintaining the full injection pressure for an extended time period after the mould cavity is full.

31 The method according to claim 30 wherein the full injection cycle lasts 5 seconds and the injection process maintains full injection back pressure for 90 seconds to ensure the polymer is held under constant feed pressure. 32 The method according to any one of claims 28 to 31 wherein the mould cavity is configured for moulding a spiral element having a stepped groove having a wide shallow section and a narrow deeper section centrally located within the shallow section and wherein the deeper section comprises a plurality of enlargements therein, the method further comprising:

providing a plurality ejector pins located in a spiral arrangement and aligned with each of the enlargements.

33 The method according to claim 32 further comprising:

providing an ejector assembly aligned with a centre of said spiral element. 34 The method according to any one of claims 28 to 33 further comprising:

providing water cooling means for said injection tool;

after inject/on of the polymer, coo/ing said injection mould tool to solidify the polymer; and

removing the spiral component from said mould cavity.

35 The method according to any one of claims 28 to 34 wherein the polymer is polycarbonate and the manifold is maintained at 270° ± 5 °. 36 The method according to claim 34 further comprising cooling the injection tool to reduce the temperature of the spiral element to 120° ± 5°.