Luminaire

Abstract

The luminaire comprises an elongate casing having elongate first and second parts, and a mounting bracket 17 for attachment to a mounting surface. At least a portion of the second part is transparent.

Description

The invention relates to a luminaire. In some embodiments, the invention relates to a type of luminaire that is sometimes referred to as an “anticorrosive” luminaire; “non-corrosive” luminaire; “corrosion-proof” luminaire; or a “vapour proof” luminaire (hereinafter “anticorrosive luminaire”). Anticorrosive luminaires are often used in warehouses, factories, workshops and car parks where the anticorrosive luminaire may be exposed to water, dust and impacts. The luminaires are typically elongate. For example, historically anticorrosive luminaires used fluorescent bulbs for illumination whereas in recent times the bulbs have been replaced by a solid state lighting device, such as an LED lighting device, to improve the efficiency and longevity of the light source. Typically, anticorrosive luminaires are installed in one of three ways: 1. attached to a suspended cable; 2. surface mounted to a ceiling or beam; and 3. surface mounted to a BESA box. During installation, mounting brackets are attached to the ceiling, the suspended cable or the BESA box and then the anticorrosive luminaire is attached to the brackets. The anticorrosive luminaire includes an elongate casing and the brackets engage the luminaire towards the ends of the casing. In some instances, the position of the bracket may be adjustable by a limited amount to provide limited adjustment. However, difficulties can occur when the ceiling is not entirely flat or that there are obstacles adjacent the area where the luminaire is to be installed or where the distance between the BESA boxes is less than the distance between the mounting positions on the luminaire. If any of these issues occurs, it may not be possible to install the luminaire at all or it may be necessary to devise a unique mounting solution for the situation, which can be time consuming and expensive. Accordingly it is desirable to have a luminaire that is arranged such that is easier to install, or to at least provide the installer with greater installation flexibility so that it can be installed in more circumstances. Accordingly, the invention seeks to provide a luminaire that addresses at least one of the above-mentioned problems, or at least provides an alternative to known luminaires. According to one aspect, there is provided a luminaire according to claim 1. The mounting bracket can be positioned anywhere along the length of the mounting rial. Since the mounting rail extends along at least 70% of the length of the first part of the casing, the installer has a very high level of flexibility for positioning the luminaire during installation. The invention enables the installer to install the luminaire in situations where prior art devices cannot be installed, or where it would be very difficult to install prior art luminaires. According to another aspect of the invention there is provided a luminaire. The luminaire can include an elongate casing having a first elongate part and a second elongate part. At least a portion of the second elongate part can be optically transparent. The luminaire can include at least one lighting device located within the elongate casing. The lighting device can be a solid-state lighting device, such as an LED lighting device. The LED lighting device can include at least one printed circuit board (PCB). The LED lighting device can include at least one LED. The LED lighting device can include at least one LED driver. The luminaire can include a mounting bracket. The mounting bracket can be arranged to attach the elongate casing to a mounting surface. The first elongate part of the casing can include a mounting rail. The mounting rail can have a length that extends longitudinally along at least 70% of the length of the first elongate part of the casing. Increasing the length of the mounting rail increases the installation flexibility. In some embodiments the mounting rail can extend longitudinally along at least 75% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 80% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 85% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 90% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 95% of the length of the first part of the elongate casing, or the mounting rail that extends longitudinally along around 100% of the length of the first part of the elongate casing. The mounting bracket can be arranged to engage the mounting rail. The position of the mounting bracket can be adjustable with respect to the mounting rail. The mounting bracket can be arranged to slide along the mounting rail. In some embodiments, the mounting bracket can be arranged to slide along the full length of the mounting rail. The mounting bracket can be releasably attachable to the mounting rail. Typically, the mounting rail passes through a central portion of the first elongate part of the casing. The mounting rail can be arranged with respect to the first part of the casing, such that the centre of the mounting rail in a longitudinal direction is coincident with the centre of the first part of the casing in the longitudinal direction. The mounting rail has a length RL, and the mounting rail can extend outwards from the centre of the first part of the casing, in the longitudinal direction, by a distance RL / 2 towards a first end of the first part of the casing. The mounting rail can extend outwards, in the longitudinal direction, from the centre of the first part of the casing by a distance RL / 2 towards a second end of the first part of the casing. The mounting rail can have a first lateral side that runs longitudinally along the mounting rail. The mounting bracket can include a first part that is arranged to engage the first lateral side of the mounting rail. The first lateral side of the mounting rail can include a first engagement formation. The first engagement formation can comprise at least one first rib that extends longitudinally along at least part of the length of the first lateral side of the mounting rail and / or a first recess that extends longitudinally along at least part of the length of the first lateral side of the mounting rail. The mounting bracket can be arranged to engage the first engagement formation. The first rib can extend along the full length of the first lateral side of the mounting rail. The first rib can extend along a part of the length of the first lateral side of the mounting rail. The first recess can extend along the full length of the first lateral side of the mounting rail. The first recess can extend along a part of the length of the first lateral side of the mounting rail. The first engagement formation can comprise a plurality of first ribs which are aligned in the longitudinal direction. Each first rib can extend along a different portion of the first lateral side of the mounting rail. The first ribs in at least one pair of adjacent first ribs can be separated in the longitudinal direction by a gap. In some embodiments, the first ribs in each pair of adjacent first ribs are separated by a gap. Typically, the gaps have the same size. The bracket can be sized and shaped to bridge the gap between the pair of adjacent first ribs. The gap can have a gap length. The bracket can have a bracket length. The bracket length can be greater than the gap length. This feature helps to ensure that the mounting bracket is able to slide over a gap between two ribs without disengaging the mounting rail. The gap length is the distance, in the longitudinal direction of the mounting rail, between adjacent ends of the first ribs in the pair of first ribs. The bracket length is the dimension of the bracket in the longitudinal direction of the mounting rail. The bracket length can be at least 1.5 times larger than the gap length, can be at least 1.8 times larger than the gap length, and can be at least 2 times larger than the gap length. The larger the bracket length in proportion to the gap length the better the transition from one rib to another. The or each first rib can have an engagement surface that faces generally towards the second elongate part of the casing. The first part of the mounting bracket can be arranged to engage the engagement surface. The first recess can be located below the or each first rib and at least part of the first part of the mounting bracket can be arranged to fit with the first recess. The first part of the mounting bracket can be resilient. The mounting bracket can include resilient material. The mounting bracket can include metal, for example spring steel. The first part of the mounting bracket can include a wall that tapers inwards. The wall that tapers inwards can be prised outwards to disengage the first engagement formation. The first part of the mounting bracket can include a finger grip portion. The finger grip portion can be arranged to enable a user to manually disengage the first part of the mounting bracket from the first engagement formation. The mounting rail can have a second lateral side that runs longitudinally along the mounting rail. The mounting bracket can include a second part that is arranged to engage the second lateral side of the mounting rail. The second lateral side of the mounting rail can include a second engagement formation. The second engagement formation can comprise at least one second rib that extends longitudinally along at least part of the length of the second lateral side of the mounting rail and / or a second recess that extends longitudinally along at least part of the length of the second lateral side of the mounting rail. The mounting bracket can be arranged to engage the second engagement formation. The second rib can extend along the full length of the second lateral side of the mounting rail. The second rib can extend along a second part of the length of the second lateral side of the mounting rail. The second recess can extend along the full length of the second lateral side of the mounting rail. The second recess can extend along a second part of the length of the second lateral side of the mounting rail. The second engagement formation can comprise a plurality of second ribs. The second ribs can be aligned in the longitudinal direction. Each second rib can extend along a different portion of the second lateral side of the mounting rail. The second ribs in at least one pair of adjacent second ribs can be separated in the longitudinal direction by a gap. In some embodiments, the second ribs in each pair of adjacent second ribs can be separated by a gap. Typically, the gaps have the same size. The bracket can be sized and shaped to bridge the gap between the pair of adjacent second ribs. The gap can have a gap length. The bracket can have a bracket length The bracket length can be greater than the gap length. This feature helps to ensure that the mounting bracket is able to slide over a gap between two ribs without disengaging the mounting rail. The gap length is the distance, in the longitudinal direction of the mounting rail, between adjacent ends of the second ribs in the pair of second ribs. The bracket length is the dimension of the bracket in the longitudinal direction of the mounting rail. The bracket length can be at least 1.5 times larger than the gap length, can be at least 1.8 times larger than the gap length, and can be at least 2 times larger than the gap length. The or each second rib can have an engagement surface that faces generally towards the second elongate part of the casing. The second part of the mounting bracket can be arranged to engage the engagement surface. The second recess can be located below the or each second rib. At least part of the second part of the mounting bracket can be arranged to fit with the second recess. The mounting bracket can include a third part that connects the first and second parts of the mounting bracket together. The third part can sit transversely across the mounting rail in a condition wherein the mounting bracket engages the first and second engagement formations. The third part of the mounting bracket can include at least one mounting formation, such as an aperture or a protrusion, which can be arranged to engage a mounting surface or a mounting device. For example, the mounting formation can be arranged to receive a screw element to fix the mounting bracket to a mounting surface or a mounting device. The third part of the mounting bracket can include a plurality of mounting formations. The second part of the mounting bracket can be resilient. The second part of the mounting bracket can include a wall that tapers inwards. The wall can be prised open to disengage the second engagement formation. The second part of the mounting bracket can include a finger grip portion. The finger grip portion can be arranged to enable a user to manually disengage the second part of the mounting bracket from the second engagement formation. At least one first rib can include a set of ridges arranged transversely to the length of the first rib. The ridges provide the rib with strength and stiffness, and helps to ensure that the rib can be formed correctly, for example during a manufacturing process, such as a moulding process. At least one second rib can include a set of ridges arranged transversely to the length of the second rib. The ridges provide the rib with strength and stiffness, and helps to ensure that the rib can be formed correctly, for example during a manufacturing process, such as a moulding process. The luminaire can include at least one further mounting bracket. The or each further mounting bracket can be arranged according to any configuration described herein. Each mounting bracket can be similarly arranged. In some embodiments, the luminaire includes a plurality of mounting brackets, for example the luminaire can include: two mounting brackets, three mounting brackets, four mounting brackets, five mounting brackets, six mounting brackets, seven mounting brackets or eight mounting brackets. Each mounting bracket can be slidable along at least a portion of the mounting rail. It will be appreciated that when an embodiment includes a single mounting bracket, the mounting bracket is slidable along the full length of the of the mounting rail. When an embodiment includes a plurality of mounting brackets, while each mounting bracket individually can be capable of sliding along the full length of the mounting rail, when a plurality of mounting brackets are mounted on the mounting rail, in some embodiments they can interfere with one another. For example, a first mounting bracket may limit the movement of a second mounting bracket along the mounting rail, and the second mounting bracket may limit the movement of the first mounting bracket along the mounting rail. The length of the first part of the elongate casing can be at least o.6m long, at least o.8m long, at least i.om long, or at least 1.2m long. The first part of the elongate casing can have a width to length ratio of at least 1:10, preferably at least 1:15, and more preferably at least 1:20. The width is the maximum width of the first part of the casing. The length is the maximum length of the first part of the casing. The first elongate part of the casing can comprise a first moulded component, and can include plastics material, such as polycarbonate. Typically, at least part of the first elongate part of the casing is optically opaque. The second elongate part of the casing can comprise a second moulded component, and can include plastics material, such as polycarbonate. Typically, at least part of the second elongate part of the casing is optically transparent. The luminaire can comprise an anticorrosive luminaire. The luminaire can have a high Ingress Protection (IP) rating for protection against water ingress and dust. For example, the luminaire can have an IP rating of at least IP65. This enables the luminaire to be used in damp or humid conditions without the luminaire malfunctioning. The luminaire can have a high Impact Protection (IK) rating. For example, the luminaire can have an IK rating of at least IK08. Embodiments of the invention will now be described by way of example only with reference to the drawings, wherein: Figure 1 is an isometric view of a luminaire according to a first embodiment of the invention; Figure 2 is an isometric view of the embodiment of Figure 1 from a different angle; Figure 3 is a plan view of an underside of the embodiment of Figure 1; Figure 4 is a side view of the embodiment of Figure 1; Figure 5 is a plan view of a top side of the embodiment of Figure 1; Figure 6 is an enlarged isometric view of a first end of the embodiment of Figure 1; Figure 7 is an enlarged isometric view of a second end of the embodiment of Figure 1; and Figure 8 is an enlarged end view of the second end of the embodiment of Figure 1. Figures 1 to 8 show a luminaire 1 (sometimes referred to as a “light fitting” or “light fixture”), according to an embodiment of the invention. Typically, the luminaire 1 is of a type that that is sometimes referred to as: an “anticorrosive luminaire. The luminaire i includes an elongate casing 3 having a first elongate part 3a and a second elongate part 3b. The length CL of the elongate casing 3 is typically at least 0.6m, for example the length maybe: 0.6m, 0.7m, 0.8m, 0.9m, 1.0m, 1.1m, 1.2m, 1.3m, 1.4m, 1.5m, 1.6m, 1.7m, 1.8m, 1.9m, 2m. The width CW of elongate casing is typically at least 70mm, and can be greater than or equal to 80mm, 90mm or 100mm. Typically the width CW of the casing is less than or equal to 150mm, and is typically less than or equal to 140mm. Typically, the luminaire 1 has a high IP rating (Ingress Protection), typically at least IP65 or IP66 rated for protection against water ingress and dust, which enables the luminaire 1 to be used in damp or humid conditions without the luminaire malfunctioning. Preferably the luminaire has a high IK rating (Impact Protection), for example IK08 to IK10 rated for good impact resistance. The high IP rating can be achieved, for example by providing suitable seals at joints and apertures. The high IK ratings can be achieved by selecting a suitable material for the casing, such as plastics material for example polycarbonate, and / or wall thickness for the casing 3. In a condition where the first elongate part 3a is mounted to the second elongate part 3b, the casing 3 forms an enclosure that houses a lighting device (not shown), which is typically a solid-state lighting device having an arrangement of LEDs mounted on one or more PCBs and at least one LED driver. The first elongate part 3a is separable from the second elongate part 3b and is releasably attachable to the second elongate part 3b. The luminaire 3 includes a plurality of fasteners 5 that are arranged to releasably attach the first elongate part 3a to the second elongate part 3b. The fasteners 5 are distributed along the length CL of the first elongate part 3a and that are located on each lateral side 3ai,3a2 of the first elongate part 3a. In Figure 1, 12 fasteners 5 are provided, six fasteners 5 located on each lateral side 3ai,3a2 of the first elongate part 3a of the casing for a luminaire 1 having a casing length CL of approximately 1.5m, however it will be appreciated that the number of fasteners 5 can be increased or decreased according to requirements. Also, the number of fasteners 5 can be different for different casing lengths CL, for example a casing length of 1.2m may have 10 fasteners 5 distributed along the length of the first elongate part 3a. Each faster 5 can be of any suitable type for releasably attaching the second elongate part 3b of the casing to the first elongate part 3a of the casing. For example, in some embodiments, each fastener 5 comprises an over centre type fastener. Typically, each fastener 5 comprises a fastening member 5a that is moveable, translationally and / or pivotably, between a locking position, in which the fastening member 5a engages the second elongate part of the casing and clamps the second elongate part 3b of the casing to the first elongate part 3a of the casing, and a non-locking position, in which the second elongate part 3b of the casing is disengaged and is not clamped to the first elongate part 3a of the casing. When all of the fastening members 5a are in their respective non-locking positions, the second elongate part 3b of the casing can be separated from the first elongate part 3a of the casing. The first elongate part 3a of the casing includes a mounting rail 7. The mounting rail 7 extends along a substantial part of the length CL of the first elongate part 3a of the casing. The mounting rail 7 passes through a central portion of the mounting rail in a longitudinal direction. Typically, the mounting rail length RL is at least 70% of the length CL of the first elongate part 3a of the casing and can be up to 100% of the length CL of the first elongate part 3a of the casing. In some arrangements, the mounting rail length RL is at least 75% of the length CL of the first elongate part 3a of the casing, at least 80% of the length CL of the first elongate part 3a of the casing, at least 85% of the length CL of the first elongate part 3a of the casing, at least 90% of the length CL of the first elongate part 3a of the casing, at least 95% of the length CL of the first elongate part 3a of the casing, or 100% of the length CL of the first elongate part 3a of the casing. The greater the mounting rail length RL, the greater the flexibility that the installer has to attach the luminaire 1 to a mounting device or mounting surface, since there are more positions that mounting brackets can be located on the casing in order to better attach the luminaire to the mounting device or mounting surface. Typically, the mounting rail 7 is arranged with respect to the first part of the casing 3a, such that the centre of the mounting rail 7 is coincident with the centre of the first part of the casing in the longitudinal direction. That is, the mounting rail 7 extends outwards from the centre of the first part of the casing 3a by a distance RL / 2 towards a first end of the first part of the casing 3a, and the mounting rail 7 extends outwards from the centre of the first part of the casing 3a by a distance RL / 2 towards a second end of the first part of the casing 3a. The mounting rail 7 comprises a body 7a, which is typically an elongate central part of the first elongate part 3a of the casing, and is therefore aligned with a central elongate axis Z-Z of the first elongate part 3a of the casing. A plurality of ribs 9 protrude outwards from the body 7a. At least one rib 9 protrudes outwards from a first lateral side 731 of the body 7, wherein the at least one rib 9 runs along the full length RL of the mounting rail, or at a least a substantial part of the length RL of the mounting rail. For example, one rib 9 can be arranged to run along the full length of the first lateral side 7ai of the body 7, or substantially along the full length of the first lateral side 7ai of the body 7. Alternatively, a plurality of ribs 9 can protrude outwards from the first lateral side 7ai of the body and the plurality of ribs 9 are arranged to approximate to a single rib 9 which runs along the full length RL of the first lateral side 731 of the body 7. For example, the plurality of ribs 9 can be arranged such that each rib 9 is elongate, each rib 9 is axially aligned, and each rib 9 is spaced apart from an adjacent rib 9 by a respective gap 11. The at least one rib can protrude perpendicularly outwards from the first lateral side 7ai of the body 7. At least one rib 9 protrudes outwards from a second lateral side 732 of the body 7, wherein the at least one rib 9 runs along the full length RL of the mounting rail, or at a least a substantial part of the length RL of the mounting rail. For example, one rib 9 can be arranged to run along the full length of the second lateral side 7a2 of the body 7, or substantially along the full length of the second lateral side 7a2 of the body 7. Alternatively, a plurality of ribs 9 can protrude outwards from the second lateral side 732 of the body and the plurality of ribs 9 are arranged to approximate to a single rib 9 which runs along the full length RL of the second lateral side 732 of the body 7. For example, the plurality of ribs 9 can be arranged such that each rib 9 is elongate, each rib 9 is axially aligned, and each rib 9 is spaced apart from an adjacent rib 9 by a respective gap 11. The gap length GL between two adjacent ribs 9 is the distance between two adjacent ribs 9 generally in the direction of axis Z-Z (see Figure 5). Typically, all gaps 11 have the same gap length GL. The at least one rib can protrude perpendicularly outwards from the second lateral side 732 of the body 7. Having 3 plurality of ribs 9 on each lateral side 731,732 of the mounting rnil body 7, rather thnn hnving 3 respective single rib 9 which runs nlong the full length RL of each lateral side 731,732 of the mounting rail body 7, improves the manufacturability and performnnce of the luminaire 1. The inventors have found that respective single ribs 9 running the full length of the respective lateral sides 731,732 of the mounting rail body have an incrensed risk of warping nfter the moulding process. By having 3 plurality of ribs 9 separated by gaps 11 on each lateral side 731,732 of the mounting rail body, the tendency for warping is significnntly reduced. Since each rib 9 is shorter than n rib 9 that runs along the full length of the mounting rail, typically, the shorter ribs 9 are stiffer. Typically, st least three ribs 9, nnd preferably at least four ribs 9, are provided on each lateral side 731,732 of the mounting rail body. In the embodiment of Figure 1, five ribs 9 are provided on each lateral side 731,732 of the mounting rail body. A first recess 15 is provided beneath the ribs 9 on the first lateral side 731 and a second recess 15 is provided beneath the ribs 9 on the second lateral side 732. The ribs 9 and / or recesses 15 provide engagement formations. Each rib 9 can include an arrangement of ridges 13, which protrude outwards from an upper surface of rib. The ridges 13 improve the rigidity of the of the ribs 9. The luminaire 1 includes at least one, and preferably a plurality, of mounting brackets 17. Each mounting bracket 17 is arranged to engage the mounting rail 7 and is arranged to connect with a mounting surface, such as a ceiling, wall or beam, or a mounting device, such as a bracket, cable or frame. Two mounting brackets 17 are shown in the Figures, however any practicable number of mounting brackets can be used, for example one mounting bracket 17, two mounting brackets 17, three mounting brackets 17, four mounting brackets 17, five mounting brackets 17, six mounting brackets 17, seven mounting brackets 17, or eight mounting brackets 17. The position of each mounting bracket 17 is adjustable with respect to the mounting rail 7. For example, each mounting bracket 17 can be slidably mounted to the mounting rail 7. This enables the position of each mounting bracket 17 to be continuously adjustable along the length of the mounting rail 7. It will be appreciated that if there is a single mounting bracket 17, it will be adjustable along the full length RL of the mounting rail 7. For embodiments including a plurality of mounting brackets 17, the position of a first mounting bracket 17 on the mounting rail 7, may limit the available positions of a second mounting bracket 17 mounted on the mounting rail 7. Each mounting bracket 17 can comprise a first part 17a that is arranged to slidably engage ribs 9 located on the first lateral side 7ai of the mounting rail, a second part 17b that is arranged to slidably engage ribs 9 located on the second lateral side 732 of the mounting rail, and a third part 17c that connects the first and second parts 17a, 17b of the bracket. Each of the first and second parts 17a,17b are shaped to engage undersides of the ribs 9, that is, faces of the ribs 9 that face generally downwards towards the second elongate part 3b, the casing 3. Typically, the undersides of the ribs 9 are smooth to enable the brackets 17 to move continuously with respect to the ribs. However, in some embodiments, it is possible to include location formations on ribs 9 to facilitate discrete positions of the brackets 17 along the mounting rail 7, and the brackets 17 can include location formations that are arranged to engage the location formations on the ribs 9 in or to select the discrete positions. Each bracket 17 can be removably attachable to the mounting rail 7. For example, at least the first and second parts of the bracket 17a,17b can be sufficiently resilient to enable the separation between the first and second parts 17a,17b to be increased to prise the bracket 17 open and disengage the ribs 9. The first and second parts 17a,17b can each include a wall 17c that tapers inwards towards the mounting body 7a and a lip i7f that engages the underside of the ribs 9 and that is located in the recess 15. Each tapering wall 17c can be arranged to flex in order to enable its respective lip I7f to disengage the ribs 9. Each bracket 17 can be made from plastics material and / or metal. For example, each bracket can be made from steel, such as spring steel. At least one of the first and second parts 17a,17b of the bracket can include a finger grip formation 17g to enable the first and second parts 17a,17b to be prised apart. The bracket length BL, which is the dimension of the bracket 17 that is generally in line with the mounting rail axis Z-Z (see Figures 5 and 7), is greater than the gap length GL. Thus each bracket 17 is sufficiently long such that the bracket 17 is able to bridge the gaps 11. That is, when sliding the bracket 17 along the mounting rail 7 and traversing gaps 11, the bracket 17 remains engaged with the currently engaged ribs 9 until the adjacent ribs 9 are engaged. Typically, the bracket length BL is at least 1.5 times the gap length GL, and preferably at least twice the gap length GL, to ensure there is a good connection between the bracket 17 and the currently engaged ribs 9 whilst traversing the gaps 11. If the gaps 11 have different gap lengths GL, typically the bracket length BL is at least twice the maximum gap length GL. The third part is typically planar or includes a planar mounting portion. The third part 17c can include at least one mounting formation i7d, such as an aperture or protrusion, that is arranged to enable the bracket 17 to be attached to the mounting surface or mounting device. For example, as shown in Figure 6, the third part 17c of the bracket can include an arrangement of apertures I7d, each of which can receive a fixing member, such as a protruding member from a mounting device or a screw element to fix the bracket 17 to the mounting surface or mounting device. Optionally, the luminaire 1 can include a first gland 19 located at a first end 4 of the casing 3. Optionally, the luminaire 2 includes a second gland 19 located at a second end 6 of the casing 3. Typically, the first gland 19 is attached to the first part of the casing 3a. Typically, the second gland 19 is attached to the first part of the casing 3a. The glands 19 enable cables to enter and exit the luminaire 1 in a sealed manner. Optionally, the casing 3 can include at least one zone of weakness 21 in the first part of the casing 3a. The zone of weakness 21 allows an aperture to be formed in the first part of the casing 3a, for example to receive additional electrical wiring. Typically, the casing 3 includes a plurality of zones of weakness distributed along the length of the first part of the casing 3a. For example, at least one of the first lateral side 3ai of the first part of the casing 3a, the second lateral side 332 of the first part of the casing 3a, and an upper surface of the mounting rail 7 can include includes a plurality of zones of weakness distributed along the length of the first part of the casing 3a. For example, each of the first and second lateral sides 3ai,3a2 of the first part of the casing 3a can include n zones of weakness 21, wherein n is in the range 3 to 10. The upper surface of the mounting rail 7 can include m zones of weakness 21, wherein m is in the range 3 to 15. The larger the number of zones of weakness 21 the greater the installation flexibility. In the Figures, the lateral sides have five zones of weakness 21 and the upper surface of the mounting rail includes nine zones of weakness 21. When the luminaire 1 is installed, typically it will either be: 1. suspended; 2. surface mounted to a ceiling or beam; or 3. surface mounted to a BESA box. During installation, the mounting brackets 17 are typically attached to the ceiling or beam, the suspended cable or the BESA box, for example the brackets 17 can be screwed to the ceiling, beam or BESA box. The mounting rail 7 of the luminaire 1 is then clipped onto the mounting brackets 17 such that the mounting brackets 17 engage the mounting rail 7 and support the casing 3. Since the mounting brackets 17 can be positioned anywhere along the length of the mounting rail 7, this gives the installer a large degree of flexibility to position the mounting brackets 17 on the mounting surface, wherever it is convenient to do so. It will be appreciated by the skilled person that modifications can be made to the above embodiments that fall within the scope of the invention, for example the second elongate part 3b of the elongate casing can be pivotally attached to the first elongate part 3a along one side, and can have a plurality of fasteners located on an opposite side. This arrangement provides access to the interior of the casing, but the first and second elongate parts 33,3b of the casing are not entirely separable from one another. At least some of the fasteners 5 can be located on the second elongate part 3b of the casing. In this arrangement, each fastener 5 that is located on the second elongate part 3b of the casing fastener 5 comprises a fastening member 5a that is moveable between a locking position, in which the fastening member 5a engages the first elongate part 3a of the casing and clamps the first elongate part 3a of the casing to the second elongate part 3b of the casing, and a non-locking position, in which the first elongate part 3b of the casing is disengaged and is not clamped to the second elongate part 3b of the casing. In some embodiments at least one of the fasteners 5 is mounted on the first elongate part 3a of the casing and at least one fastener 5 is mounted on the second elongate part 3b of the casing. While the embodiment of Figure 1 has the gaps 11 on the first lateral side 731 of the mounting rail longitudinally aligned with the gaps 11 on the second lateral side of the mounting rail 7a2, it is possible to have the gaps 11 on the first lateral side longitudinally offset from the gaps 11 on the second lateral side 732. The description presents exemplary embodiments and, together with the drawings, serves to explain principles of the invention. However, the scope of the invention is not intended to be limited to the precise details of the embodiments or exact adherence with all method installation steps, since variations will be apparent to a skilled person and are deemed also to be covered by the claims. Terms for components used herein should be given a broad interpretation that also encompasses equivalent functions and features. In some cases, several alternative terms (synonyms) for structural features have been provided but such terms are not intended to be exhaustive. Descriptive terms should also be given the broadest possible interpretation; e.g. the term "comprising" as used in this specification means "including" such that interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner. Directional terms such as “vertical”, “horizontal”, “up”, “down”, “upper” and “lower” maybe used for convenience of explanation usually with reference to the illustrations and are not intended to be ultimately limiting if an equivalent function can be achieved with an alternative dimension and / or direction. The description herein refers to embodiments with particular combinations of configuration steps or features, however, it is envisaged that further combinations and cross-combinations of compatible steps or features between embodiments will be possible. Indeed, isolated features may function independently as an invention from other features and not necessarily require implementation as a complete combination. Any feature from an embodiment can be isolated from that embodiment and included in any other embodiment. The term “at least one of” is to be interpreted in the sense of “and / or”. For example, the term “at least one of the first bracket part and the second bracket part” is to be interpreted as meaning any one of the following: the first bracket part alone; the second bracket part alone; or the combination of the first and second bracket parts. As another example, the term “at least one of the first part, the second part and the third part” is to be interpreted as meaning any one of the following: the first part alone; the second part alone; the third part alone; the combination of the first part and the second part; the combination of the first part and the third part; the combination of the second part and the third part; or the combination of the first part, the second part and the third part.

Claims

1. A luminaire, comprising: an elongate casing having a first elongate part and a second elongate part, wherein at least a portion of the second elongate part is optically transparent; at least one lighting device located within the elongate casing; and a mounting bracket arranged to attach the elongate casing to a mounting surface; wherein the first elongate part of the casing includes a mounting rail having a length that extends longitudinally along at least 70% of the length CL of the first elongate part of the casing, the mounting bracket is arranged to engage the mounting rail and the position of the mounting bracket is adjustable with respect to the mounting rail.

2. The luminaire of claim 1, wherein the mounting rail extends longitudinally along at least 75% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 80% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 85% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 90% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 95% of the length of the first part of the elongate casing, or the mounting rail that extends longitudinally along around 100% of the length of the first part of the elongate casing.

3. The luminaire of claim 1 or 2, wherein the mounting bracket is arranged to slide along the mounting rail.

4. The luminaire of any one of the preceding claims, wherein the mounting bracket is releasably attachable to the mounting rail.

5. The luminaire of any one of the preceding claims, wherein the mounting rail is arranged with respect to the first part of the casing, such that the centre of the mounting rail in a longitudinal direction is coincident with the centre of the first part of the casing in the longitudinal direction.

6. The luminaire of any one of the preceding claims, wherein the mounting rail has a first lateral side that runs longitudinally along the mounting rail, and the mounting bracket includes a first part that is arranged to engage the first lateral side of the mounting rail.

7. The luminaire of claim 6, wherein the first lateral side of the mounting rail includes a first engagement formation, such as at least one first rib that extends longitudinally along at least part of the length of the first lateral side of the mounting rail and / or a first recess that extends longitudinally along at least part of the length of the first lateral side of the mounting rail, and the mounting bracket is arranged to engage the first engagement formation.

8. The luminaire of claim 7, wherein the first engagement formation comprises a plurality of first ribs which are aligned in the longitudinal direction, wherein each first rib extends along a different portion of the first lateral side of the mounting rail, and the first ribs in at least one pair of adjacent first ribs are separated in the longitudinal direction by a gap.

9. The luminaire of claim 8, wherein the bracket is sized and shaped to bridge the gap between the pair of adjacent first ribs.10.The luminaire of claim 9, wherein the gap has a gap length, the bracket has a bracket length, and the bracket length is greater than the gap length.

11. The luminaire of claim 10, wherein the bracket length is at least 1.5 times larger than the gap length, is preferably at least 1.8 times larger than the gap length, and more preferably still is at least 2 times larger than the gap length.12.The luminaire of any one of claims 7 to 11, wherein the or each first rib has an engagement surface that faces generally towards the second elongate part of the casing, and the first part of the mounting bracket is arranged to engage the mounting surface.13.The luminaire of any one of claims 7 to 12, wherein the first recess is located below the or each first rib and at least part of the first part of the mounting bracket is arranged to fit with the first recess.14-The luminaire of any one of claims 7 to 13, wherein the first part of the mounting bracket is resilient.

15. The luminaire of any one of claims 7 to 14, wherein the first part of the mounting bracket includes a finger grip portion, which is arranged to enable a user to manually disengage the first part of the mounting bracket from the first engagement formation.16.The luminaire of any one of claims 6 to 15, wherein the mounting rail has a second lateral side that runs longitudinally along the mounting rail, and the mounting bracket includes a second part that is arranged to engage the second lateral side of the mounting rail.

17. The luminaire of claim 16, wherein the second lateral side of the mounting rail includes a second engagement formation, such as at least one second rib that extends longitudinally along at least part of the length of the second lateral side of the mounting rail and / or a second recess that extends longitudinally along at least part of the length of the second lateral side of the mounting rail, and the mounting bracket is arranged to engage the second engagement formation.18.The luminaire of claim 17, wherein the second engagement formation comprises a plurality of second ribs which are aligned in the longitudinal direction, wherein each second rib extends along a different portion of the second lateral side of the mounting rail, and the second ribs in at least one pair of adjacent second ribs are separated in the longitudinal direction by a gap.19.The luminaire of claim 18, wherein the bracket is sized and shaped to bridge the gap between the pair of adjacent second ribs.

20. The luminaire of claim 19, wherein the gap has a gap length, the bracket has a bracket length, and the bracket length is greater than the gap length.21.The luminaire of claim 20, wherein the bracket length is at least 1.5 times larger than the gap length, is preferably at least 1.8 times larger than the gap length, and more preferably still is at least 2 times larger than the gap length.

22. The luminaire of any one of claims 17 to 21, wherein the or each second rib has an engagement surface that faces generally towards the second elongate part of the casing, and the second part of the mounting bracket is arranged to engage the mounting surface.

23. The luminaire of any one of claims 17 to 22, wherein the second elongate part of the casing includes a second recess located below the or each second rib and at least part of the second part of the mounting bracket is arranged to fit with the second recess.

24. The luminaire of any one of claims 17 to 23, wherein the mounting bracket includes a third part that connects the first and second parts of the mounting bracket together, wherein the third part sits transversely across the mounting rail, when the mounting bracket engages the first and second engagement formations.25.The luminaire of claim 24, wherein the third part of the mounting bracket includes at least one mounting formation, such as an aperture or a protrusion, which is arranged to engage a mounting surface or a mounting device.

26. The luminaire of any one of claims 17 to 25, wherein the second recess is located below the or each second rib and at least part of the second part of the mounting bracket is arranged to fit with the second recess.27.The luminaire of any one of claims 17 to 26, wherein the second part of the mounting bracket is resilient.

28. The luminaire of any one of claims 17 to 27, wherein the second part of the mounting bracket includes a finger grip portion, which is arranged to enable a user to manually disengage the second part of the mounting bracket from the second engagement formation.

29. The luminaire of any one of the preceding claims, including at least one further mounting bracket.04 12 24AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWS:-CLAIMS1. A luminaire, comprising: an elongate casing having a first elongate part and a second elongate part, wherein at least a portion of the second elongate part is optically transparent; at least one lighting device located within the elongate casing; and a mounting bracket arranged to attach the elongate casing to a mounting surface; wherein the first elongate part of the casing includes a mounting rail having a length that extends longitudinally along at least 70% of the length of the first elongate part of the casing, the mounting bracket is arranged to engage the mounting rail and the position of the mounting bracket is adjustable with respect to the mounting rail; wherein the mounting rail has a first lateral side that runs longitudinally along the mounting rail, the first lateral side of the mounting rail includes a first engagement formation, and the mounting bracket is arranged to engage the first engagement formation, the first engagement formation comprises a plurality of first ribs which are aligned in the longitudinal direction, wherein each first rib extends along a different portion of the first lateral side of the mounting rail, and the first ribs in at least one pair of adjacent first ribs are separated in the longitudinal direction by a gap, and the bracket is sized and shaped to bridge the gap between the pair of adjacent first ribs.

2. The luminaire of claim 1, wherein the mounting rail extends longitudinally along at least 75% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 80% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 85% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 90% of the length of the first part of the elongate casing, the mounting rail that extends longitudinally along at least 95% of the length of the first part of the elongate casing, or the mounting rail that extends longitudinally along around 100% of the length of the first part of the elongate casing.

3. The luminaire of claim 1 or 2, wherein the mounting bracket is arranged to slide along the mounting rail.04 12 244- The luminaire of any one of the preceding claims, wherein the mounting bracket is releasably attachable to the mounting rail.

5. The luminaire of any one of the preceding claims, wherein the mounting rail is arranged with respect to the first part of the casing, such that the centre of the mounting rail in a longitudinal direction is coincident with the centre of the first part of the casing in the longitudinal direction.

6. The luminaire of any one of the preceding claims, wherein the gap has a gap length, the bracket has a bracket length, and the bracket length is greater than the gap length.

7. The luminaire of any of the preceding claims, wherein the bracket length is at least 1.5 times larger than the gap length, is preferably at least 1.8 times larger than the gap length, and more preferably still is at least 2 times larger than the gap length.

8. The luminaire of any one of the preceding claims, wherein each first rib has an engagement surface that faces generally towards the second elongate part of the casing, and a first part of the mounting bracket is arranged to engage the engagement surface.

9. The luminaire of claim 8, wherein the first engagement formation includes a first recess that extends longitudinally along at least part of the length of the first lateral side of the mounting rail, and the first recess is located below the or each first rib and at least part of the first part of the mounting bracket is arranged to fit with the first recess.10.The luminaire of claim 8 or 9, wherein the first part of the mounting bracket is resilient.

11. The luminaire of any one of claims 8 to 10, wherein the first part of the mounting bracket includes a finger grip portion, which is arranged to enable a user to manually disengage the first part of the mounting bracket from the first engagement formation.04 12 2412.The luminaire of any one of the preceding claims, wherein the mounting rail has a second lateral side that runs longitudinally along the mounting rail, the second lateral side of the mounting rail includes a second engagement formation and the mounting bracket is arranged to engage the second engagement formation.13.The luminaire of claim 12, wherein the second engagement formation comprises a plurality of second ribs which are aligned in the longitudinal direction, wherein each second rib extends along a different portion of the second lateral side of the mounting rail, and the second ribs in at least one pair of adjacent second ribs are separated in the longitudinal direction by a gap, wherein the bracket is sized and shaped to bridge the gap between the pair of adjacent second ribs.14.The luminaire of claim 13, wherein the gap has a gap length, the bracket has a bracket length, and the bracket length is greater than the gap length.

15. The luminaire of claim 14, wherein the bracket length is at least 1.5 times larger than the gap length, is preferably at least 1.8 times larger than the gap length, and more preferably still is at least 2 times larger than the gap length.16.The luminaire of any one of claims 13 to 15, wherein the or each second rib has an engagement surface that faces generally towards the second elongate part of the casing, and a second part of the mounting bracket is arranged to engage the engagement surface.

17. The luminaire of claim 16, wherein the second engagement formation includes a second recess that extends longitudinally along at least part of the length of the second lateral side of the mounting rail, and the second recess is located below the or each second rib and at least part of the second part of the mounting bracket is arranged to fit with the second recess.18.The luminaire of claim 16 or 17, wherein the second part of the mounting bracket is resilient.04 12 2419-The luminaire of any one of claims 16 to 18, wherein the second part of the mounting bracket includes a finger grip portion, which is arranged to enable a user to manually disengage the second part of the mounting bracket from the second engagement formation.

20. The luminaire of any one of claims 16 to 19 when dependent on claim 8 or any other claim dependent on claim 8, wherein the mounting bracket includes a third part that connects the first and second parts of the mounting bracket together, wherein the third part sits transversely across the mounting rail, when the mounting bracket engages the first and second engagement formations.21.The luminaire of claim 20, wherein the third part of the mounting bracket includes at least one mounting formation, such as an aperture or a protrusion, which is arranged to engage a mounting surface or a mounting device.

22. The luminaire of any one of the preceding claims, including at least one further mounting bracket.

23. The luminaire of any one of the preceding claims, having an Ingress Protection (IP) rating for protection against water ingress and dust of at least IP65.

24. The luminaire of any one of the preceding claims, having an Impact Protection (IK) rating of at least IK08.

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