GB2489034A

GB2489034A - A LED lighting unit

Info

Publication number: GB2489034A
Application number: GB1104518.4A
Authority: GB
Inventors: Glynn Gore
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-03-17
Filing date: 2011-03-17
Publication date: 2012-09-19
Anticipated expiration: 2031-03-17
Also published as: GB201104518D0; GB2489034B

Abstract

A LED lighting unit (10, fig 1) is formed from a housing (12, fig 1) with an extruded casing member 14 having an outer wall (18, fig 5) defining an internal cavity (20, fig 5) and end closure members (16, fig 1). The casing member 14 has at least one internal transverse member (24, fig 5) to divide the internal cavity (20, fig 5) into two internal cavity portions (20a,20b fig 5). A LED light source 36 is located in one of the cavity portions and a power source 32 is located in another internal cavity portion. The casing member 14 has one or more apertures 38 in the outer wall (18, fig 5) to permit light emitted by the LED to pass through.

Description

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Technical Field of the Invention

The present invention relates to lighting units and in particular led lighting units.

The invention relates especially, but not exclusively, to portable lighting units for use with bicycles and the like.

Background to the Invention

Lighting units incorporating led light sources are known. It is becoming increasing popular to use led light sources in portable lighting units such as push bike lights and emergency lighting units. These often have power source in the form of one or more batteries or a battery pack which may be housed in the lighting unit. For more powerful lighting applications, a separate battery pack located outside the lighting unit itself is sometimes provided.

The existing lighting units have a number of drawbacks. A number of portable lighting units have housings made of plastics which are not particularly robust. A further issue is that led light sources can generate significant amounts of heat which is difficulto dissipate, particularly where the housing is made of plastics. Where high power led light sources are used, these may require the use of a Li-ion battery pack whose performance can be adversely affected by heat. This is a particular issue where the battery pack is mounted in the same housing as the light source. Thus in many higher powered applications, it is common to have the battery pack separate from the lighting unit itself A further issue is that the known housing arrangements are often complex and relatively expensive to produce.

There is a need then for a lighting unit which overcomes, or at least mitigates some or all of the above mentioned disadvantages of the known lighting units.

There is also a need for a method of manufacturing a lighting unit which overcomes, or at least mitigates some or all of the disadvantages of the known methods of manufacture.

Summary of the Invention

In accordance with a first aspect of the invention, there is provided a led lighting unit comprising a housing including an extruded easing member having an outer wall portion defining an internal cavity, the housing also including closure members mounted to the easing member at either end, the casing member having at least one transverse member projecting inwardly from the outer wall portion to at least partially divide the internal cavity into at least two internal cavity portions, at least one led light source located in one of the internal cavity portions and a power source for the light source located in a further one of the internal cavity portions, the casing member having one or more apertures in the outer wall portion, said one or more apertures being arranged so as to pennit light emitted by said at least one light source to pass therethrough.

One or more of the end closure members may be removably mounted to the easing member.

The, or each, removably mounted end closure member may be mounted to the casing member by means of a twist fit engagement, which may be in the form of a screw thread or a bayonet type fitting.

A seal may be provided between the casing member and the, or each, removably mounted end closure member.

The casing member may have a circular boss at one end at least to which an end closure is mounted. The end closure may be in the form of an end cap.

The at least one led light source may be mounted on or attached to the, or a, transverse member.

The at least one led light source may comprise at least one bar-type led light source. There may be one or more elongate aperture in the outer wall portion of the casing member through which light emitted from the one or more bar-type led light sources can pass. The transverse member may comprise a central mounting portion to which the one or more bar-type led light sources are mounted, portions of the transverse member either side of the central mounting portion subtending an angle between themselves. The angled portions of the transverse member may fonn, or have mounted thereto, reflective surfaces for directing light emitted from the one or more bar-type led light sources through the one or more apertures.

The at least one led light source may comprise at least one spot type led light source. In which case, an aperture may be provided in the outer ease through which light from the, or each, spot type light source, can pass. The, or each, aperture may be circular.

In one embodiment, the casing member includes a single transverse member extending across the internal cavity between generally opposing regions of the outer wall portion dividing the internal cavity into two separate compartments, a forward compartment in which the at least one light source is located and a rear compartment in which the power source is located. There may be a layer of insulation between the battery pack and the transverse member.

In an alternative embodiment, the casing member includes a pair of spaced transverse members extending across the internal cavity between generally opposing regions of the outer wall portion to divide the internal cavity into three compartments, a forward compartment in which the at least one light source is located, a rear compartment in which the power source is located and a central compartment between the forward and rear compartments. One or more openings may be provided in generally opposed regions of the outer wall portion in between the spaced transverse members to allow air to flow through the central compartment. The casing member may have one or more formations on its outer surface configured to guide air into the central compartment through the one or more openings when an air flow passes over the casing member.

The outer wall portion of the casing member may be substantially circular in lateral cross-section, The, or each, aperture in the casing member may be closed by a transparent or translucent cover. The cover may comprise a collimating lens. The cover may be part of a lens and reflector assembly.

At least one end closure member may be adjustably mounted to the casing member and may comprise a control means for controlling at least one output parameter of the at least one light source. The control means may comprise a Hall sensor or a potentiometer or the like.

The casing member may be made of aluminium and may have cooling fins on the outer surface of the outer wall portion.

The lighting unit may be a cycle light.

In accordance with a second aspect of the invention, there is provided a method of manufacturing a casing member for an led lighting unit, the method comprising: a. extruding a length of material having a profile defining an outer wall portion surrounding an internal cavity and at least one transverse member at least partially dividing the internal cavity into at least two internal portions; b. forming one or more openings in generally opposed regions of the outer wall portion in between the spaced transverse members.

The method may comprise forming a twist fit mounting formation for an end closure member on at least one end of the extruded length. The method may comprise forming a twist fit mounting formation for an end closure member at both ends of the extruded length. The, or each, twist fit mounting formation may be a screw thread. The method may comprise machining a circular boss at least one end of the extruded length and forming the twist fit mounting formation on the circular boss.

The method may comprise extruding a length of material having a profile defining an outer wall portion surrounding an internal cavity and a pair of spaced transverse members fully dividing the internal cavity into three compartments, a forward compartment, a rear compartment and a central compartment between the forward and rear compartments.

The method may also comprise forming one or more openings in generally opposed regions of the outer wall portion in between the spaced transverse members. The method may comprise removing the material forming the outer wall portion only in a central region of the casing member.

The material may be aluminium.

According to a third aspect of the invention, there is provided a led lighting unit comprising a housing defining a first compartment housing a light source and second compartment housing a power source, the housing defining a duct between the first and second compartments through which air can flow. The housing may be shaped to encourage air to enter and pass through the duct when the housing is subject to an air flow passing over it. The housing may have one or more guide formations for directing air into the duct when a flow of air passes over the housing in a first direction. The first compartment may be located in front of the rear compartment. The housing may be shaped to encourage a flow of air through the duct when the lighting unit is moved in a forward or a rearward direction, The lighting unit may be a cycle light.

According to a fourth aspect of the invention, there is provided a led lighting unit comprising a housing including an extruded casing member having an outer wall portion defining an internal cavity, the housing also including closure members mounted to the casing member at either end, in which the outer wall portion of the casing member is substantially circular and a circular boss is provided at at least one end of the casing member to which an end closure is mounted. The end closure may be mounted to the boss by means of a twist fit connection such as a screw thread or a bayonet type connection.

Detailed Description of the Invention

In order that the invention may be more clearly understood several embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a front view of an end region of a first embodiment of a lighting unit in accordance with the invention; Figure 2 is a lateral cross-sectional view through the lighting unit of Figure 1, taken on line A-A; Figure 3 is a front view of an end region of an extruded casing member forming part of the lighting unit of Figure 1; Figure 4 is a cross-sectional view through the casing member of Figure 3 taken on line B-B; Figure 5 is a view similar to that of Figure 3 but showing the casing member before a light aperture is formed; Figure 6 is a view similar to that of Figure 2 but illustrating an alternative embodiment of a lighting unit in accordance with the invention; Figure 7 is an exploded view from the front of an end region of a further embodiment of a lighting unit in accordance with the invention; Figure 8 is a lateral cross-sectional view through the lighting unit of Figure 7, taken on line C-C; Figure 9 is a cross-sectional view through an extruded casing member forming part of the lighting unit of Figure 7, taken on line C-C, but showing the casing member before a light aperture is formed; Figure 10 is a longitudinal cross-sectional view through an end region of a lighting unit in accordance with the invention incorporating a control arrangement;

S

Figure 11 is a front view of a further embodiment of a lighting unit in accordance with the invention; Figure 12 is a perspective view from one end of the lighting unit of Figure 11; Figure 13 is a perspective view from the front and to one side of the lighting unit of Figure 11; and Figure 14 is a somewhat schematic lateral cross sectional view through the lighting unit of Figures 11 to 13 taken on line D-D.

The same reference numerals but increased by 100 in each case will be used to identify the same features or features that perform the same function in each of the embodiments described below.

Figures 1 to 5 illustrate a lighting unit 10 in accordance with a first embodiment of the invention. Only one end region of the lighting unit 10 is shown in Figure 1 but it should be understood that the lighting unit has a second, opposite end region that is substantially a mirror image of the end region shown. The length of the lighting unit between the end regions can be selected as desired.

The lighting unit 10 includes a housing, indicated generally at 12, which comprises a casing member 14, two end closure members 16 (only one of which is shown) and a transparent/translucent cover 13. The casing member 14 is an extruded component which, prior to subsequent machining, has substantially constant cross-sectional profile along its length, as shown in Figure 5. The casing member 14 and the end closure members 16 can be manufactured from any suitable materials, such as metals, polymers, plastics and the like but advantageously are manufactured from aluminium (including aluminium alloys). Aluminium has the advantages of being relatively strong whilst also being light weight and resistant to corrosion. The use of a metallic material such as aluminium is also advantageous for dissipating heat generated when the lighting unit is in use, as will be discussed in more detail below.

FigureS shows the cross-sectional profile of the extrusion from which the easing member 14 is produced. The easing member has an outer wall portion 18 which is substantially circular and defines an inner cavity 20. Radial cooling fins 22 are provided over the majority of the outer surface of the outer wall portion apart from an area at the front. The cooling fins 22 could be provided over the entire outer surface outer wall portion and/or other cooling formations can be used.

A transverse member 24 extends between opposed regions of the outer wall portion 18 across the cavity 20 dividing it into a front portion 20a and a rear portion 20b.

The transverse member 24 has a central mounting portion 26 conected to the outer wall portion 18 on either side by means of further portions 28 which subtend an angle between themselves. In the arrangement shown in Figure 2, the angled. further portions 28 connect directly to the outer wall portion 18. Figure 5 illustrates a variation in which the angled, further portions 28 are connected to the outer wall portion by means of aligned vertical portions 30. Either of these arrangements, or indeed many different variations, can be adopted.

As illustrated in Figure 2, the rear portion2Ob of the internal cavity forms a compartment for housing a power supply such as a battery pack 32. The battery pack may be a Li-ion battery pack but any suitably power supply can be used. Thermal insulation 34 is positioned between the battery pack 32 and the transverse member 24 to thermally isolate the two, at least to an extent. A light source 36 in the form of one or more bar-type led lights are attached to the mounting portion of the transverse member 24 in the front portion 20a of the cavity where it is isolated from the battery pack by the transverse member 24. The light source 36 directs light forwardly and an aperture 38 is formed in the outer wall portion 18 to allow the light to pass through in a forward direction. The aperture 38 is machined in to the casing member 12 after extrusion. In the present embodiment, a single elongate aperture 38 extends over the niajority of the length of the easing member apart from regions at either end. However, more than one aperture 38 could be formed spaced along the length of the casing member. The aperture 38 is closed by the transparent/translucent cover 13 which is affixed over the aperture to form a water tight seal. The cover 13 can be attached in any suitable manner such as by bonding or by use of fixings such as screws. A seal may be provided between the cover 13 and the casing member 14. The cover 13 may be in the form of a lens and/or could be coloured.

The angled ftirther portions 28 of the transverse member 24 are configured to direct light emitted from the light source 18 towards the aperture 38 in the manner of a reflector. The front surfaces of the further portions 28 may be treated (e.g. polished or burnished) or coated so that they reflect the light or reflective materials can be attached to the surfaces.

The light source 36 is connected to the battery pack 32 by means of suitable wires or other connectors 40 which can be routed through openings formed in the transverse member 24 after extrusion. Control circuitry for the light, which may include a PCB can also be mounted inside either or both of the front and rear portions of the internal cavity.

The end closure members 16 are mounted to either end of the casing member 14 to form a fully weather proof enclosure. In the present embodiment, both end closure members 16 are in the form of an end cap removably mounted to the casing member by means of a screw thread. However, in an alternative embodiment one or both of the end closure members 16 could be non-removably mounted to the casing member, for example by means of welding or bonding, and so may not be in the form of an end cap.

To provide a mounting for the end caps 16, each end region of the casing member extrusion is machined to form a circular boss 42. A groove 44 is formed in an inner region of the boss to receive an 0-ring (245 in figure 7) or other seal member and a screw thread 46 is formed on an outer portion of the boss. Each end closure cap 16 has a corresponding internal thread 48 so that it can be screwed onto the boss 42 with part of the cap contacting the 0-ring to form a water tight seal, With both end caps 16 in position, the housing forms a weather proof and robust housing for the lighting unit.

Rather than a screw thread, other types of twist fit connections can be used to mount one or both of the end caps 16, such as a bayonet type connection.

A control switch for the lighting unit may be incorporated into one of the end caps 16 or elsewhere in the housing and a connection to allow the battery pack to be re-charged can also be incorporated in to housing if required.

The lighting unit 10 is compact and lightweight whilst being robust and weatherproof. The lighting unit 10 is also easy to manufacture. The casing member 14, which is the main component, is produced by extruding the basic profile and cutting into lengths. Each length is then machined to form the, or each, aperture 38, the end cap mounting bosses 42 and other features. The use of an extrusion having a substantially circular outer wall portion 18 is advantageous as it makes machining of the extrusion easier, particularly the formation of the end cap bosses 42. For example, the circular outer profile is more readily located in a machine chuck than other non-circular profiles.

A further advantage of the lighting unit 10 is that the light source 36 and the battery pack 32 are thermally isolated from one another to an extent in their separate compartments 20a, 20b by the transverse member 28. Heat generated by the light source is conducted along the transverse member 28 on which it is mounted to the outer wall portion 18 which is cooled by the surrounding air. The provision of cooling fins 22 on the outer surface of the outer wall portion 18 aids transfer of the heat into the ambient air.

This helps to prevent overheating of the battery pack 32 and the lighting unit in general.

In the embodiment shown in Figure 2, the cover 13 is curved to match the generally circular profile of the outer wall portion. However, as illustrated in Figure 6, in an alternative embodiment 110, the casing member 114 can be adapted to receive a generally flat cover 113. In this embodiment, the outer wall portion 118 has a thickened region 150 at the front which is machined out to form an elongate recess about the aperture 138 in which a flat cover 113 can be mounted in a water tight manner. The transverse member 128 in this case extends straight across the internal cavity 120 and the cover forms part of an assembly which includes a reflector 152 for directing light from the light source out through the aperture 138 and the cover. A combined cover and reflector assembly could also be used where the cover is curved as in the first embodiment.

Figure 6 also illustrates how formations 154 for mounting the lighting unit 110 to a mount or other support can be formed as part of the extruded outer profile of the casing member 114. In this case, the formations 154 take the form of undercut groves which are adapted to receive a correspondingly shaped mounting member (256, Figure 9) with a sliding fit. The mounting member is adapted to be affixed to a support, which may be part of a bicycle, so that it can be introduced into the undercut groove 154 and the casing member 114 slid on to the mounting member. The mounting formations 154 may only extend over part of the length of the easing member to allow the mounting member to be inserted. This can be achieved by removing one or more sections of the formations 154 as part of the machining process after extrusion. Alternatively, one or both of the end closure members may be dimensioned and/or profiled to allow the mounting member to be inserted from one end of the casing member, In the embodiment shown in Figure 6, two mounting formations 154 are provided, one at the rear and one at the bottom of the casing member 114 to allow the lifting fixture to be mounted from behind or below, However, only one mounting formation 154, or more than two as illustrated in Figures 8 and 9, can be provided.

The lighting unit 110 illustrated in Figure 6 is otherwise constructed and operated in much the same way as the lighting unit 10 of the first embodiment described above, to which the reader should refer. Whilst the outer wall portion 118 has a thickened region at the front, it is otherwise generally circular to allow for the formation of a circular boss at one or both ends for mounting an end cap and for ease of machining generally.

Figures 7 to 9 illustrate a further embodiment of a lighting unit 210 in accordance with the invention. The lighting unit 210 is substantially constructed and operated in the same manner as the lighting units 10, ito of the first and second embodiments described above, to which the reader should refer, and so only the differences will be described in detail.

The lighting unit 210 differs from the previous embodiments in that it incorporates one or more spot type leds 236 as the light source rather than bar type leds.

The present embodiment has at least two spot type leds as illustrated in Figure? but there could be only one or any number as desired. The casing member 214 in this embodiment has a basic profile which is similar to that of the second embodiment 114 as shown in Figure 6. Accordingly, the transverse member 228 in this embodiment extends substantially straight across the internal cavity 220 to divide it into a front portion 220a and a rear portion 220b. The outer wall portion 218 has region of increased thickness 250 along the front into which a circular light aperture 238 is formed for each spot type led 236. Each of the apertures is closed by a circular cover 213 which forms part of an assembly including a generally conical reflector 252 for directing the light from the led 236 through the cover. The cover 213 in this ease may be or include a collimating lens and may be transparent or translucent and/or may be coloured. Each cover 213 is held in position by means of a threaded collar 256 which engages with a corresponding thread 258 formed in a side wall region of a recess about each of the apertures. However, any suitable means of holding the cover 213 in position can be used including any of those discussed above in relation to the first and second embodiments.

As with the previous embodiments, a power source 232, which may be in the form of a battery pack and more particularly a Li4on battery pack, is located in the rear portion 220b of the cavity and the led light sources 236 are located in the front portion 220a so as to be separated by the transverse member 228. A layer of thermal insulation 234 is positioned between the power source 232 and the transverse member 228. A PCB 259 forming part of the control circuitry is mounted to the transverse member 228 in the front portion. The provision of a straight transverse member 28 provides a suitable location point for the PCB but it could be positioned at any suitable location.

Mounting formations 254 for co-operation with a mounting member 256 for attaching the lighting unit to a support are provided on the outer surface of the outer wall portion 218 in a manner similar to that described above in relation to the second embodiment 110.

Figure 10 illustrates how a control may be incorporated into one of the end caps of a lighting unit 310. This arrangement can be adopted in any of the embodiments described herein.

The end cap 316 in this arrangement is similar to the end caps in the previously described embodiments but has a slightly longer or deeper side wall region 360. The end cap 316 is in screw threaded engagement with the threaded boss 342 on the end of the easing member 314. A clearance 362 is proved between the axial end of the side wall region of the cap and a lip 364 on the easing member at the end of the circular boss 342 to allow the axial position of the end cap to be adjusted relative to casing member using the screw thread. Axial movement of the end cap 316 is limited by means of one or more abutments 366 on the end cap which project inwardly into a recess 368 in the circular end boss 342, The abutments 366 may be in the form of screws that can be removed or retracted to allow the end cap 316 to be fully unscrewed. A spring 370 is mounted between the end cap 316 and the casing member 214 to eliminate or reduce backlash in the thread.

A magnet 372 is mounted to the inner surface of the end wall of the end cap and a hall effect sensor 374 is supported inside the casing member facing the magnet such that the sensor is able to detect movement of the magnet 372 in an axial directions towards or away from it caused by twisting the end cap 316. The sensor 374 is connected to the control circuitry and the arrangement can be used to control the brightness of the light in the manner of a dimmer switch or some other output parameter.

This is only one example of how a control arrangement can be incorporated into the lighting unit and it will be appreciated that other arrangements could be used. For example, rather than a Hall effect sensor, an alternative proximity type sensor could be used. In a further alternative, a potentiometer can be used as part of the dimmer switch and connected such that axial movement of the end cap relative to the casing members varies the voltage to the light source. A similar arrangement can also be used to provide an on/off switch for the lighting unit, This might be archived, for example, by incorporating a mechanical switch which is activated by screwing the end cap 316 in and out.

Figures 11 to 14 illustrate a further embodiment of a lighting unit 410 having additional cooling means and which is particularly suited to applications where the unit is moved during use or otherwise subject to an air flow, such as in a light for a bicycle.

The lighting unit 410 according to this embodiment is generally constructed and operated in the same manner as the previous embodiment 310 described above, to which the reader should refer, and accordingly only the significant differences will be described.

The casing member 414 of the lighting unit has two spaced transverse members 428a, 428b which extend across the internal cavity in a generally parallel path. The transverse members divide the internal cavity into a front portion 420a in which the light sources 436 are mounted, a rear portion 420b in which the battery pack 432 is mounted and a third central portion 420c between the two transverse members. This arrangement is in itself advantageous as it provides for a greater degree of thermal separation between the light sources 436 and the battery pack 432 as the air in the central cavity portion 420c acts as a thermal break. However, to further improve cooling one or more apertures 478 are formed in opposed regions of the outer wall portion between the two transverse members 428a, 428b to allow air to circulate through the central cavity portion 420c.

In the embodiment 410 shown in Figures 11 to 14, substantially all the material in the generally opposed regions of the outer wall portion 418 between the transverse member s428a, 428b is removed over substantially the entire length of the casing member 414 except for regions at either end so that the central cavity portion 420c effectively forms a duct through which air can flow.

The lighting unit 410 as illustrated is intended to be moved in a forward direction in use (as indicated by arrows 479 in Figure 12), such as would be the case for a front light on a bicycle. Forward in this context refers to the direction in which the light is emitted from the unit. The transverse members 428a, 428b are shaped so that the opening or openings into the duet at one end, in this case the lower end, faces slightly to the front of the casing member and that the opening or openings at the other, upper end faces slightly to the rear to encourage air to flow through the duct as the lighting unit is moved in a forward direction as indicated by the arrows 480. Guide formations 482, 484 in the form of lips project from the outer wall portion either side of the lower, inlet opening to the duct to guide air into the duct whilst a further guide formation 486 in the form of a lip projects from the outer wall portion at the leading edge of the upper, outlet opening to deflect the air exiting the duct so that it is entrained in the air flow 488 over the lighting unit to further encourage air flow through the duct.

For use in a lighting unit which will be moved in a rearward direction in use, such as would be the case for a rear light on a bicycle, the shape of the transverse members and the guide formations can be modified to encourage air to flow through the central cavity duet when the unit is moved through the air in a rearward direct.

The air flow guides illustrated in Figures 11 to 14 can also be adopted for use with lighting units which are not intended to be moved in use but which may be subject to an air flow over the housing. For example, light units intended for use as emergency lighting out of doors may be subject to an air flow over the housing and the housing can be shaped to encourage air flowing over the housing to enter and pass through the duet.

To ensure the front cavity portion 420a and the rear cavity portion 420b are water tight, the end cap arrangements are adapted so that water entering the central cavity duet 420c is not able to enter either of the front or rear cavity portions past the end cap. For example, a seal member may be provided which locates between the end face of the cap the axial end of the easing member and so abuts the axial end of the transverse members 428a, 428b to prevent water leaking into the front and rear cavity portions.

Figure 14 illustrates part of the easing member 414 where the material has been removed. The dashed lines 490 indicate the path of the outer wall portion before removal of the material, from which it can be seen that the outer wall portion 418 is generally circular when extruded. The end regions where the material is not renioved will retain their generally circular configuration to allow for machining of circular end bosses to receive end caps in the manner described above.

Whilst the cooling duct arrangement illustrated in Figures 11 to 14 is particularly effective for use with high powered spot type led light sources, it could equally be adopted for use in a lighting unit having one or more bar type led light sources as in the first and second embodiments 10, 110 as described above.

The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims. Whilst the embodiments described are particular suitable for use as small portable lighting units for bicycles and the like the same basic principles and arrangements can also be applied to lighting units for other applications such as inspection and emergency lighting.

Claims

CLAIMSI. A led lighting unit comprising a housing including an extruded easing member having an outer wall portion defining an internal cavity, the housing also including closure members mounted to the easing member at either end, the easing member having at least one transverse member projecting inwardly from the outer wall portion to at least partially divide the internal cavity into at least two internal cavity portions, at least one led light source located in one of the internal cavity portions and a power source for the light source located in a further one of the internal cavity portions, the casing member having one or more apertures in the outer wall portion, said one or more apertures being arranged so as to permit light emitted by said at least one light source to pass therethrough.
2. A led lighting unit as claimed in claim I, wherein at least one of the end closure members is removably mounted to the casing member.
3. A led lighting unit as claimed in claim 1 or claim 2, wherein the, or each, removably mounted end closure member is mounted to the easing member by means of a twist fit engagement.
4, A led lighting unit as claimed in claim 3, wherein the, or each, removably mounted end closure member is mounted to the casing member by means of a screw thread.
5. A led lighting unit as claimed in any one of claims 1 to 4, wherein a seal is provided between the casing member and the, or each, removably mounted end closure member.
6. A led lighting unit as claimed in claim 3 or claim 4, in which the casing member has circular boss at one end at least to which an end closure in the form of an end cap is mounted.
7. A led lighting unit as claimed in any one of the preceding claims, wherein the at least one led light source is mounted on or attached to the, or a, transverse member.
8. A led lighting unit as claimed in any one of the preceding claims, wherein the at least one led light source comprises at least one bar-type led light source.
9. A led lighting unit as claimed in claim 8, wherein one or more elongate aperture is formed in the outer wall portion of the casing member through which light emitted from the one or more bar-type led light sources can pass.
10. A led lighting unit as claimed in claim 8 or claim 9,wherein the transverse member comprises a central mounting portion to which the one or more bar-type led light sources are mounted, portions of the transverse member either side of the central mounting portion subtending an angle between themselves.
11. A led lighting unit as claimed in claim 10, wherein the angled portions of the transverse member form, or have mounted thereto, reflective surfaces for directing light emitted from the one or more bar-type lcd light sources through the one or more apertures.
12. A led lighting unit as claimed in any one of claims 1 to 7, wherein the at least one led light source comprises at least one spot type led light source.
13. A led lighting unit as claimed in claim 12, wherein an aperture is provided in the outer wall of the casing member for the, or each, spot type light source.
14. A led lighting unit as claimed in claim 13, in which the, or each aperture is circular.
15. A led lighting unit as claimed in any of the preceding claims, wherein the casing member includes a single transverse member extending across the internal cavity between generally opposing regions of the outer wall portion fully dividing the internal cavity into two compartments, a forward compartment in which the at least one light source is located and a rear compartment in which the power source is located.
16. A led lighting unit as claimed in any one of claims I to 14, wherein the casing member includes a pair of spaced transverse members extending across the internal cavity between generally opposing regions of the outer wall portion to divide the internal cavity into three compartments, a forward compartment in which the at least one light source is located, a rear compartment in which the power source is located and a central compartment between the forward and rear compartments.
17. A led lighting unit as claimed in claim 16, wherein one or more openings are provided in opposed regions of the outer wall portion in between the spaced transverse members to allow air to flow through the central compartment.
18. A led lighting unit as claimed in claim 17, wherein the casing member comprises a lip formation on its outer surface configured to guide air flow passing over the casing member into the central compartment through the one or more openings in one of the opposed regions of the outer wall portion.
19. A led lighting unit as claimed in any of the preceding claims, wherein the outer wall portion of the easing member is substantially circular in lateral cross-section.
20. A led lighting unit as claimed in any one of the preceding claims, wherein the, or each, aperture in the casing member is closed by a transparent or translucent cover.
21. A led lighting unit as claimed in claim 20, wherein the cover comprises a collimating lens.
22, A led lighting unit as claimed in claim 20 or 21, wherein the cover is part of a lens and reflector assembly.
23. A led lighting unit as claimed in any one of the preceding claims, wherein at least one end closure member is adjustably mounted to the casing member and comprises a control means for controlling at least one output parameter of the at least one light source.
24. A led lighting unit as claimed in claim 23, wherein the control means comprises a 1-Jail sensor or a potentiometer.
25. A led lighting unit substantially as herein before described, with reference to and as illustrated in the accompanying drawings.
26. A method of manufacturing a casing member for an led lighting unit, the method comprising: a. extruding a length of material having a profile defining an outer wall portion surrounding an internal cavity and at least one transverse member at least partially dividing the internal cavity into at least two internal portions; K forming one or more apertures in the outer wall portion partially encircling one of the internal portions of the cavity each component length.
27. A method as claimed in claim 26, wherein the method comprises forming a twist fit mounting formation for an end closure member on at least one end of the extruded length.
28. A method as claimed in claim 27, wherein the method comprises forming a twist fit mounting formation for an end closure member at both ends of the extruded length.
29. A method as claimed in claim 27 or claim 28, wherein the, or each, twist fit mounting formation is a screw thread.
30. A method as claimed in any one of claims 27 to 29, wherein the method comprises machining a circular boss at at least one end of the extruded length and forming the twist fit mounting formation on the circular boss.
31. A method as claimed in any one of claims 26 to 30, wherein the method comprises: a. extruding a length of material having a profile defining outer wall portion surrounding an internal cavity and a pair of spaced transverse members fully dividing the internal cavity into three compartments, a forward compartment, a rear compartment and a central compartment between the forward and rear compartments.
32. A method as claimed in claim 31, the method comprising forming one or more openings in generally opposed regions of the outer wall portion in between the spaced transverse members.
33. A method as claimed in claim 32, in which the method comprises removing the material forming the outer wall portion only in a central region of the easing member.
34. A method of manufacturing a led lighting unit substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.