An LED luminaire (10) comprising: a main body portion (12) adapted, in use, to house an LED light panel (24); a mount (14) for securing, in use, the luminaire (10) to a surface; a driver unit (62); and a hinge (16, 42, 44) adapted to hingedly connect the main body portion (12) to the mount (14), wherein the hinge (16, 42, 44) comprises a, hollow interior volume for accommodating the driver unit (62), and wherein the driver unit (62) comprises a water-resistant housing.

CROSS REFERENCE TO RELATED APPLICATION

The present application is the U.S. national stage application of International Application PCT/GB2015/050754, filed Mar. 16, 2015, which international application was published on Sep. 17, 2015 as International Publication WO 2015/136313 A1. The International Application claims priority of Great Britain Patent Application 1404632.0, filed Mar. 14, 2014.

FIELD OF THE INVENTION

This invention relates to luminaires, and in particular, but without limitation, to LED luminaires suitable for use outdoors.

BACKGROUND

LED luminaires are becoming an increasingly popular choice for lighting installations due to their favourable power consumption, longevity and light quality properties, compared with conventional incandescent, cold cathode and gas discharge lighting systems of equivalent specifications. Unlike, for example, incandescent bulbs, which can operate directly from an AC mains power supply, most LEDs require a relatively low-voltage, DC power source. Moreover, because the longevity of LEDs is closely related to the power (voltage and/or current) supplied to the LEDs over time, careful consideration needs to be given to powering LED lighting systems.

It is therefore commonplace for LED luminaires to comprise a light panel, comprising one or more LEDs (connected together in series, parallel, or a combination thereof) and a driver unit that is interposed between an available power supply and the light panel to condition the power to the light panel. In most applications, the driver unit is connected to a switched mains power supply at its input, and to one or more light panels at its output. The driver unit usually comprises a step-down transformer and a rectifier (for stepping-down the mains voltage to a suitable low voltage, and to convert it from AC to DC, respectively), or in certain applications, a more sophisticated inverter is used, which, whilst being generally more expensive than a transformer-rectifier unit, generally offers better control over the output to the light panel, and can improve the quality of the light emitted by the LEDs and/or their longevity.

Given that a driver unit is generally necessary in most LED lighting applications, the end user has two basic choices:

First, a shared driver unit can be used to provide power to a plurality of LED light panels. This option is generally favoured where a number of LED light panels will be relatively closely spaced, and/or where the cabling to the luminaires needs to be “low-voltage” for safety reasons. However, shared driver units result in dual wiring systems being present, i.e. mains wiring to the driver unit, and low voltage wiring between the driver unit and the light panels. Whilst such a system is not uncommon, and in certain cases, desirable, it does increase the likelihood human error when retrofit modifications are made, for example, it is possible to confuse the low-voltage and mains voltage cables.

Second, a dedicated driver unit can be provided for each LED light panel. Such a configuration greatly simplifies installation because only mains wiring is present on site, but incorporating a driver unit into each LED luminaire increases the size and weight of the luminaires, which can make them unattractive. Moreover, because LED light panels have high cooling requirements, it is usually undesirable to co-locate the driver (which generates heat itself) with the LED light panel. Thus, co-locating the driver unit and LED light panel can complicate cooling considerations, especially where passive air cooling is needed. The main commercial drawback, however, of using integrated drivers and LED panels, is that the LED luminaires tend to appear quite “boxy” and unattractive.

One known solution to this problem is provided by the present applicant's FUSION product, upon which the present invention is based. The FUSION product provides a luminaire with separate LED panel and driver housing, which are hingedly connected to one another. The driver unit is located within a hollow interior portion of the hinge and the hinge is IP-rated to withstand the elements. However, it has been found that due to the relative movement of the hinge components, a seal is difficult to achieve and thus the hinge portion is susceptible to filling with rainwater when the unit is used outdoors, or in a submerged installation, meaning that that driver unit can be subject to wet conditions and/or submersion, even when the surrounding environment is dry. Obviously, this can lead to problems over time, such as ingress of water into the driver unit. Moreover, the need for additional sealing of the hinge components can limit the dimensions of the driver, since the driver needs to be accommodated within the hinge. Using an under-sized driver is mostly undesirable because the driver may then need to work at, or beyond, its duty cycle (compared with a larger driver unit). A further problem that is often encountered with known luminaires is that of correctly affixing the luminaire to a surface, such as a wall or ceiling, which operation is often carried out at height, e.g. using a ladder or a “cherry picker”. Because the cabling for a luminaire is usually installed during a “first fix” installation, but the luminaires themselves are installed subsequently, during a “second fix” installation, the installer often has to work with relatively short lengths of cable. However, because one of the objectives of second fix installations is to conceal as much of the cabling as possible from view, the cabling enters the luminaire through the mounting, which means that the luminaire hangs from the wall, by its cable, during installation. A need therefore exists for a luminaire mounting system that provides a temporary, or a secondary, connection between the mounting and the luminaire itself, which permits an installer to use both hands, i.e. without having to support the luminaire with one hand; and/or without simply allowing the luminaire to dangle from its cable during installation of the mount.

A need therefore exists for an improved and/or an alternative LED luminaire, which addresses one or more of the above problems.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided an LED luminaire comprising: an main body portion adapted, in use, to house an LED light panel; a mount for securing, in use, the luminaire to a surface; a driver unit; and a hinge adapted to hingedly connect the main body portion to the mount, wherein the hinge comprises a hollow interior volume for accommodating the driver unit and wherein the driver unit comprises a water-resistant housing.

Suitably, the water-resistant housing is waterproof and/or the driver is IP-rated. Suitably, the driver unit is an IP-rated driver unit.

By locating a waterproof driver unit within the hollow interior volume of the hinge, physical and/or thermal separation of the driver unit and the LED light panel can be achieved. Suitably, such a configuration may enable the sealing and thermal requirements of the LED light panel and the driver unit to be considered independently. This may be useful, where, for example, the LED light panel comprises encapsulated LEDs and circuitry, which require no additional sealing from the environment, but where the driver unit is of a more conventional design, or vice-versa. Additionally or alternatively, by physically separating the driver unit from the LED light panel, the housing can be provided with cooling fins, ribs or other cooling means that are dedicated to cooling the LEDs. Additionally or alternatively, by physically separating the driver unit from the LED light panel, the heat emitted by the LEDs or the LED light panel may not be transferred to the driver unit.

Thus, the invention may open up a range of new design options and/or thermal configurations that are not possible, or available, in a conventional LED luminaire where the LEDs/LED light panel and the driver unit are co-located.

A second aspect of the invention provides a rotatable connection, suitable for connecting a mount to a luminaire, comprising a bayonet-type connector, the bayonet-type connector comprising at least two pairs of axially- and circumferentially-offset lugs adapted to engage, in use, behind a corresponding set of axially offset circumferential ribs, wherein circumferential ribs each comprise cut-outs configured to allow the respective pairs of lugs to pass therethrough, wherein the bayonet-type connection provides a first rotatable connecting position in which a first pair of lugs engage one of the circumferential ribs and a second rotatable connecting position in which two pairs of lugs engage their respective circumferential ribs.

Thus, the invention provides a connection providing first and second, axially offset rotatable connections between the mount and the luminaire.

Suitably, releasable locking means (e.g. a locking screw) is provided for locking the relative rotation of the mount and luminaire at a desired position.

The mount suitably comprises a tubular stub and a corresponding bayonet portion that fit together one inside the other. The stub suitably comprises two or more sets of axially offset lugs, a first set of which is relatively close to the end of the stub, and the other set of which is set back from the end of the stub by a certain distance. Each set of lugs suitably comprises a pair of diametrically opposing lugs, which may all be substantially the same shape and size, The two sets of lugs are suitably also circumferentially offset by a certain angle.

The bayonet portion suitably comprises an annular disc portion having a series to through holes therein through which mounting screws for the luminaire can extend, in use, to affix it to a surface. The bayonet portion suitably comprises a tubular boss which may comprise a set of radially projecting ribs.

A first one of the radially projecting ribs suitably comprises a circumferential rib that projects radially outwardly from the boss, and which has a pair of diametrically opposed cut-outs shaped to allow the lugs to pass therethrough, when correctly aligned.

A second one of the radially projecting ribs suitably comprises a second radially projecting rib, which comprises a circumferential rib that projects radially outwardly from the boss, and which has a second pair of diametrically opposed cut outs shaped to allow the lugs to pass therethrough, when correctly aligned.

The second set of cut-outs are suitably circumferentially offset by an angle equal to the offset angle of the lugs.

The boss may further comprise a set off axial ribs, which may provide rotational end stops for the lugs.

The boss may further comprise a cable cut-out to permit cabling for the luminaire to pass into the boss. Where provided, the cable cut-out suitably extends axially below the lower edge of the stub, when in the second position.

The boss may further comprise a cable channel to permit cabling for the luminaire to pass into the boss.

The main body portion is adapted, in use, to house an LED light panel. The LED light panel suitably comprises a circuit board to which one or more LEDs are electrically affixed. The LED light panel suitably comprises a transparent or translucent lens portion that overlies the LEDs, and which can be used as a primary optic, or a secondary optic, for the LEDs, i.e. to configure the LED's light output in a desired manner. Where the LED light panel comprises a lens portion, the lens portion can be sealingly affixed to the circuit board, for example, by welding, or adhering, it to the circuit board, and/or by mechanically affixing it to the circuit board with a seal interposed therebetween. Such a configuration can render the LED light panel water- and/or weather-proof. Suitably, the LED light panel is “IP-rated” from IPOO to IP68, with IP65 to IP68 being preferred.

Additionally or alternatively, the main body portion may comprise a sealed, hollow interior portion to provide protection from the elements and a transparent window behind which the LEDs or LED light panel is located.

A thermal bridge means is suitably provided between the LEDs and/or the LED light panel and the main body portion to transfer heat (by convention, but preferably conduction) from the LEDs to the main body portion, which in such an embodiment, is suitably manufactured from a thermally conductive material, such as metal (e.g. aluminium, steep, copper, etc.). The thermal bridge means, where provided, may comprise a thermally-conductive insert physically connecting the exterior of the LEDs or LED light panel to the interior main body portion, or in more sophisticated embodiments, the thermal bridge means may comprise one or more heat pipes, a forced-air cooling system and/or a heat exchanger, depending on the thermal requirements of the luminaire.

The main body portion suitably comprises heat sink elements, such as integrally formed ribs, grooves or protrusions to increase the surface area of the exterior of the main body portion, thereby making it more conducive to heat exchange with the surrounding environment (e.g. water or air).

The LEDs or LED light panel are suitably connected to the driver unit by cabling. The cabling, where provided, may comprise conventional cabling (e.g. twin core +/− earth cabling), a ribbon cable or individual cable cores. A seal, such as a cable gland, bead of sealant, bead of adhesive, etc., is suitably provided where any such cabling enters of leaves the sealed hollow interior volume of the hinge.

The mount suitably comprises a flange portion having one or more through holes therein through which holes, mounting screws can extend to affix the mount, and hence the luminaire to a surface, such as a wall, floor or ceiling. The flange portion may be integrally formed with the mount, or it may be detachably affixable thereto, for example, using a bayonet or threaded connection.

The driver unit suitably comprises an inverter, and/or a step-down transformer and/or a rectifier circuit, for converting an available power supply, such as a mains power supply, into a suitably-conditioned DC power source for powering the LED or LEDs or the LED light panel.

The hinge is adapted to hingedly connect the main body portion to the mount and suitably comprises a plurality of, generally cylindrical tube portions. In one embodiment, one cylindrical tube portion is formed integrally with the main body portion and another cylindrical tube portion is formed integrally with the mount. The respective tube portions may be sealingly connected to one another, for example, using an 0-ring seal, a resiliently deformable member, or a sealing strip interposed between abutting, or overlapping, portions of the respective tube portions.

The hinge suitably comprises end caps for closing off the ends of the tube potions, thereby forming an enclosed hollow interior portion for the driver unit to be housed within. The end caps are suitably removable, for example, by the provision of bayonet-type fittings, or screw threads, and a seal is suitably provided, such as an 0-ring seal, to seal the end cap or caps to the tube portions. In another embodiment, the end caps comprise circular discs (or components having a substantially circular outer periphery) that seat against internal flange portions of the tube portions. Again, a seal is suitably provided between the end cap plates and the flange portions to form a seal, in use. The flanges, where provided, are suitably rebated such that the end caps are flush with the ends of the tube portions, when fitted. The discs (or end caps) can be affixed to the tube portions using mechanical fasteners, such as retaining screws or grub screws.

Thus, the invention provides a hollow interior portion of the hinge, which may be a sealed hollow interior portion, for accommodating the driver unit. Such a configuration means that the hinge portion and/or the driver unit can be IP-rated in its own right (for example, both the hinge and the driver unit could be IP-rated, as a double-failsafe measure) because it can be sealingly contained within the hollow, and/or sealed hollow interior portion of the hinge.

Where the hinge portion is sealed from the environment, further advantages may flow therefrom. For example, by sealing the interior of the hinge, and hence the driver unit contained within it, from the environment, the driver unit is not subject to wet or dirty conditions and more space is available to provide convective cooling airflow within the hinge. Additionally or alternatively, the overall dimensions of the hinge can be reduced thereby improving the aesthetic of the luminaire.

DETAILED DESCRIPTION

InFIGS. 1 to 4of the drawings, a luminaire10comprises a main body portion12, a mount14and a hinge16interposed between the main body portion12and the mount14. The main body portion12is able to pivot relative to the mount14, about the axis18of the hinge16, between first and second positions, as shown particularly inFIGS. 3 and 4.

The main body portion12is manufactured from cast aluminium and is provided with a series of integrally formed cooling ribs20on a rear surface thereof, which ribs20increase the surface area of the main body portion12thereby facilitating passive convection of heat away from it, in use.

As can been seen particularly inFIG. 6of the drawings, the main body portion12comprises an integrally formed cavity22into which an LED light panel24is installed. The LED light panel comprises (although not shown in the drawings for simplicity), a PCB to which are electrically connected a number of surface-mount LEDs (an 8×3 array of 24 LEDs in the illustrated embodiment, although more or fewer LEDs may be provided), which each comprise an integrally formed lens (a “primary optic”) and which sit behind respective individual lens portions (“secondary optics”) of a transparent plastics (or glass) cover lens26. The cover lens26seals against the PCB via a bead of adhesive or sealant, thus the LEDs are sealingly encased in the LED light panel between the cover lens26and the PCB. A power cable28sealingly extends from the LED light panel and passes through a side wall30of the cavity22, via a sealing gland32.

The peripheral edge of the cavity22is provided with a part-circular rebate (not visible) into which seats an O-ring seal or gasket34. A planar cover plate36, manufactured from transparent plastics or glass, overlies the cavity22and its rear face seats against, and seals with the 0-ring seal or gasket34to form a watertight cavity within the main body portion12into which the LED light panel is received.

A generally rectangular bezel38overlies the cover plate36and clamps it in situ via retaining grub screws (not shown) which engage with suitably arranged receiving holes40of the bezel38and the main body portion12.

The LED light panel's power cable28extends into the hollow interior of the hinge portion16of the luminaire, via a gasket plate (not shown for clarity).

The hinge portion16, as is best shown inFIGS. 5, 6 and 7of the drawings, is made up of three main components: a central, generally tubular portion42, which is integrally formed with the mount14, and a pair of spaced-apart lateral generally tubular portions44, which are integrally formed with the main body portion12of the luminaire10. As can be seen fromFIGS. 5 and 6in particular, the width48of the central tubular portion42is substantially the same as (in fact, slightly smaller than) the lateral spacing50between the spaced-apart lateral tube portions44, such that when the respective components are brought together coaxially, the central tube portion42nests neatly between the lateral tube portions44, for which seeFIG. 2.

The central tube portion42is connected to the lateral tube portions44via a pair of tubular plastics bearings52. The bearings52have a castellated end54comprising a series of cut outs56, which engage with complementarily-shaped ridges58formed on the interior side wall of the central portion42. Thus, as the central portion42rotates relative to the lateral portions44, the bearings52rotate in unison with the central portion42. The bearings52additionally comprise a smooth, continuous end portion60, which provides a contact surface against which the interior side walls of the lateral tube portions44seat. Optionally, a bead of layer of sealant or grease, for example, can be applied to the contact surface to form a seal between the bearings52and the lateral tube portions44.

Adhesive is used to sealingly affix the bearings52to the central tube portion42, and a dynamic seal (not shown) is optionally interposed between the continuous end portions60of the bearings52and the interior side wall of the lateral tube portions44to form a seal therebetween. Thus, the hinge16provides a tubular cavity for accommodating a driver unit62(as shown inFIG. 7), whilst providing a relatively moveable connection between the mount14and the main body portion12of the luminaire. Further, a sealed arrangement is provided to inhibit and/or prevent the ingress of particulates (e.g. dust, dirt) and liquids (e.g. water) into the hollow interior of the hinge16.

The ends of the hinge16are sealingly closed off at their opposite ends by a semi-permanently connected end plate64and by a removable end plate assembly66. The semi-permanently connected end plate64comprises a part-tubular projection68carrying a set of radially outwardly extending lugs70that engage with complementarily, L-shaped receiving grooves72of one of the lateral tube portions44of the hinge16. The semi-permanently connected end plate64can be provided with a bead of sealant (not shown) and offered up to the end of the hinge16, inserted and rotated bayonet-wise, to semi-permanently connect it thereto. As can be seen fromFIG. 1, the end plate64lies flush with the end of the lateral tube portion44, thus providing a neat finish.

The removable end plate assembly66affixes to the other lateral tube portion44of the hinge16and comprises a disc-shaped end plate74whose peripheral edge75seats against a corresponding flange of the lateral tube. An 0-ring seal76is provided for sealing the end plate74to the interior side wall of the lateral tube portion44. An axial locking screw78is provided as well, which sealingly extends through a cylindrical part80of the end plate assembly66to engage with a correspondingly positioned, threaded receiving aperture (not visible) of the driver unit62. Thus, the removable end plate assembly66provides two functions: first, it sealingly closes-off the end of the tubular hinge16of the luminaire10; and second, it locates and stabilises the driver unit62within the hollow interior of the hinge16.

The driver unit62comprises a waterproof housing, which is suitably IP-rated. The IP-rating of the driver unit62is suitably selected to meet the requirements and installation location of the luminaire, for example, submersible (IP6-8), splash-proof (IP6-4) etc.

The mount14is shown inFIGS. 8, 9 and 10of the drawings, and is made up of: the central tubular portion42of the hinge and an integrally formed, tubular stub82, which extends radially outwardly from the tubular portion42; and a bayonet-fitting flange portion83that detachably affixes to the stub82. The stub82has an inner side wall84, which is provided with two sets of axially offset lugs86,88, a first set86of which is relatively close to the end of the stub82, and the other set88of which is set back from the end of the stub82by a distance90. Each set of lugs86,88comprises a pair of diametrically opposing lugs, which are all substantially the same shape and size, but the two sets of lugs86,88are circumferentially offset by an angle92, as can be seen inFIGS. 11 to 14of the drawings.

The bayonet-fitting flange portion83comprises an annular disc portion94having a series to through holes96therein through which mounting screws (not shown) for the luminaire10can extend to affix it to a surface (also not shown). Extending axially from the annular disc portion94is a tubular boss96which comprises a set of radially projecting ribs98,100,102having a configuration described below.

A first radially projecting rib98comprises a circumferential rib that projects radially outwardly from the boss96, and which has a pair of diametrically opposed cut-outs104shaped to allow the lugs86,88to pass therethrough, when correctly aligned. Thus, the stub82can be offered up to the boss96and the first set of lugs86aligned with the cut-outs104before being pushed axially into engagement therewith. The first set of lugs86thus pass through the cut-outs104, and the subsequent relative rotation of the stub82and boss96forms a temporary connection between the mount and the luminaire. However, the stub82and boss96are not “pushed home” at this stage and the luminaire10can be rotated relative to the mount14to facilitate installation. In other words, the luminaire10is loosely, and temporarily connected to the mount14by the first set of lugs86engaging behind the first radially projecting rib98.

The boss96additionally comprises a second radially projecting rib100, which also comprises a circumferential rib that projects radially outwardly from the boss96, and which has a second pair of diametrically opposed cut outs106shaped to allow the first set of lugs86to pass therethrough, when correctly aligned. The second set of cut-outs106are circumferentially offset by an angle92equal to the offset angle92of the lugs (as shown inFIG. 11).

As such, the stub82can be moved to a second, installed position by aligning first set of lugs86aligned with the second set of cut-outs106before pushing the stub82axially into engagement therewith yet further. The first set of lugs86thus pass through the cut-outs106, whilst the second set of lugs88pass through the first set of cut outs104and subsequent relative rotation of the stub82and boss96forms an installed connection between the mount and the luminaire. In the second position, the luminaire10can also be rotated relative to the mount14so that it can be rotated to a final position with the first set of lugs86engaging behind the second radially projecting rib100, and the second set of lugs88engaging behind the first radially projecting rib98.

The installation can be locked by tightening a locking screw108, which forms a releasable mechanical connection between the stub82and the boss96.

It will be noted that the boss96additionally comprises a set off axial ribs102that provide rotational end stops for the lugs86,88, thereby limiting the extent of rotation of the luminaire10relative to the mount14; and a cable cut-out110to permit the (mains) cabling for the luminaire10to pass into the boss96. The cable cut-out110extends axially below the lower edge of the stub82, when in the second position, as can be seen inFIG. 2, in particular.

A cable channel112is also provided, in the illustrated embodiment, to enable a cable (not shown) to pass from the interior of the mount14into a mounting surface (not shown) in a concealed manner.

The invention is not restricted to the details of the foregoing embodiment, which is merely exemplary of the invention. For example, the shape and configuration of the various components thereof, the materials and methods of manufacture etc. could be changed without departing from the scope of the invention.