GB2559961B

GB2559961B - Improved downlight with a detachable electronic module

Info

Publication number: GB2559961B
Application number: GB1702524.8A
Authority: GB
Inventors: Kelley Robert
Original assignee: Aurora Ltd
Current assignee: Aurora Ltd
Priority date: 2017-02-16
Filing date: 2017-02-16
Publication date: 2019-07-17
Anticipated expiration: 2037-02-16
Also published as: GB201702524D0; GB2559961A

Description

Improved Downliqht with a Detachable Electronic Module Field of the invention

This invention relates to improvements in a lighting unit, and in particular to a fire rated downlight using LED light source technology.

Background to the invention LED Downlight fittings or downlighters are a form of lighting unit becoming more and more widely used as light sources in domestic and commercial environments. They offer significant energy savings when compared with traditional incandescent lighting, whilst being particularly neat and unobtrusive in their appearance, since almost the entire downlight fitting is concealed behind a ceiling or other suitable panel or surface, whilst giving out a pleasing light. However, LED downlights suffer from a number of disadvantages. LED’s generate significant amounts of heat. It is important to prevent overheating of the LEDs, and associated control circuitry, since overheating will have obvious detrimental effects on the light output and service life of these components. Indeed, excessive temperatures will cause LEDs and electronic components to fail leading to premature failure of the lighting unit. To this end it is known to provide LED lighting units with cooling means in the form of a heat sink. In addition, there is a consumer driven demand for LED downlights to produce greater and greater amounts of light for a given energy input, so an output of 100 lumens per watt is common today, and this lumen per watt output is expected to rise over time. The result of this trend is that larger and larger heat sinks are required to dissipate the greater amount of heat generated in use.

As part of a further new trend, light fittings and luminaires, including downlight fittings, are increasingly becoming more intelligent as a result of the Internet of Things (loT), miniaturisation of sensors, cameras and the like, and the advent of Cloud computing. This requires additional control and communication software and hardware within a luminaire fitting, all of which takes up space as well as producing additional heat.

These developments can cause or exacerbate several problems. Firstly there is the issue of inventory management. For a particular luminaire range, a wide range of colour temperatures and colours of LEDs are required, as well as lens beam angles.

Added to that is the range of different sensors required and different communication protocols needed to communicate data from those sensor(s). Furthermore there is potentially a problem of lack of space. Downlights are usually fitted into a ceiling void, which void has a limited and fixed depth and there is not always the depth available to accommodate a downlight fitting.

It is an object of the present invention to overcome or mitigate some or all of the disadvantages outlined above.

Summary of the Invention

According to the present invention there is provided a downlight assembly according to Claim 1. A downlight assembly is described comprising a light emitting portion and a driver/control portion, wherein the light emitting portion comprises a first housing and the power/control portion comprises a second housing, the housings being attachable to and detachable from each other in use by means of an attachment means comprising a latch type arrangement, the downlight assembly further comprising a pluggable connecting cable adapted to form an electrical/data connection between the light emitting portion and the power/control portion, such that the power/control portion and the light emitting portion can be completely separated from each other in a disassembled configuration and attached together in an assembled configuration as and when required.

By constructing the downlight assembly in two separate parts, and by providing a pluggable, and therefore unpluggable, cable connection between those parts the power/control portion can be detached completely from the light emitting portion. This provides a number of advantages. There is a major cost saving advantage in terms of inventory management that has not been possible before, and reduces the number of Stock Keeping Units (SKU) required to stock a complete range. Different light emitting portions and different power/control portions can be paired together in any desired 'mix and match' combination to meet the specific needs of the customer.

Preferably the light emitting portion and/or the power/control portion incorporate a plug socket and the pluggable connecting cable is configured to be inserted into the plug socket in the light emitting portion or the power/control portion, or both. More preferably both the light emitting portion and the power/control portion incorporate a plug socket and the connecting cable incorporates a corresponding plug at each end.

Preferably the downlight assembly latch type mechanism comprises a resiliently deformable latch mechanism.

Preferably the connecting cable is housed substantially within the housings when the luminaire assembly is in its assembled configuration. It will be understood that the connecting cable may be an assembly of cables including one or more power cables and one or more data/control cables. Alternatively all the necessary connecting wires may be accommodated within a single cable.

Preferably the downlight assembly further comprises at least one cable tidy clip adapted to arrange the connecting cable within the body of the luminaire assembly, and more preferably the first housing and/or the second housing further comprise a channel adapted to accommodate part of the connecting cable when the luminaire assembly is in its assembled configuration. These one or more cable tidy clips and/or channel ensure that the connecting cable may be safely stowed away when the downlight is in an assembled configuration.

Preferably the light emitting portion comprises a collar having a front side and a rear side with an inwardly directed flange on the rear side, a solid state lighting element closing off the rear side of the collar, and a heat sink in direct contact with the solid state lighting element. Preferably the collar is made from a material with a melting point above about 900 degrees centigrade, such as mild steel.

Preferably the solid state lighting element comprises a PCB and preferably the PCB is formed from a material that melts below 900°.

Preferably the light emitting portion is fire resistant. By fire resistant it is meant that the light emitting portion is able to withstand specific temperatures for a specific period of time without failing. For example, Building Regulations in the UK for certain types of buildings require ceilings, and therefore downlights, to withstand temperatures of around 1000° centigrade for a specified period of time. The regulations in other countries may vary in both the temperature and the length of time that the ceiling/fitting must withstand that temperature. One method of achieving this fire resistance is to incorporate intumescent material adapted to expand inside the light emitting portion in the event of a fire and blocking the path of the fire. This provides the required level of fire protection by preventing any fire from getting beyond the light emitting portion.

Preferably the connecting cable between the light emitting portion and the power/control portion is of sufficient length that the power/control portion may be placed separately alongside the light emitting portion when the luminaire assembly is installed in a surface is a disassembled configuration.

The present invention also included a method of installing a luminaire assembly in a surface including the steps of> a) Providing a downlight assembly as disclosed above; b) Making an aperture of the appropriate size in the surface in which the downlight assembly is to be installed; c) Making electrical and control connections to the power/control portion as necessary; d) Disconnecting the two portions of the downlight assembly whilst retaining the electrical connections between the light emitting portion and the power/control portion; e) Inserting the power/control portion through the aperture and placing to one side of the aperture; f) Fitting a fixing ring to the light emitting portion if required; g) Inserting the light emitting portion into the aperture in the usual fashion, making sure that any springs do not foul the nearby power/control portion; h) Fitting a suitable decorative bezel to the front of the light emitting portion as and if required

Brief Description of the Drawings

Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying Figures wherein:-Figures 1 to 4 show a view from above, a view from below, a perspective view and a perspective disconnected view of a luminaire assembly according to a first embodiment of the present invention;

Figure 5 shows an enlarged view of the perspective disconnected view shown in Figure 4;

Figure 6A shows a perspective view of a luminaire with a collar at the front of a light emitting portion and Figure 6B shows a perspective view of a fixing ring prior to attachment to the collar in Figure 6A.

Description of the preferred embodiments

Luminaire assemblies in the form of downlights having a separate light emitting portion and a separate power/control portion are known from GB2543664A (Aurora Limited) the entire text of which is hereby imported by reference and is intended to form an integral part of this disclosure. Referring to Figure 3, this shows a luminaire assembly in the form of a downlight assembly 10 in its assembled configuration. Figure 1 shows a view from the back or looking down on the assembly from the rear, with the light emitting front face pointing into the page. Figure 2 shows a view from below or looking up into the light emitting front face. The assembly comprises two main parts or portions, as shown in Figures 4 and 5, being a light emitting portion 11 and a power/control portion 12, both portions being substantially tubular in cross section in this example. The components that make up the downlight assembly are shown in more detail in the perspective view illustrated in Figure 5.

The light emitting portion 11 and the power/control portion 12 are connected by a pluggable connecting cable 42. In this example the cable 42 has a plug 43, 44 at each end and these plugs are adapted to engage with corresponding sockets 45, 46 in the light emitting portion and the power/control portion respectively. Lugs 48 on the plugs engage with clips 47 on the sockets to retain the plug in its socket once fully inserted. This avoids a plug becoming accidentally detached from its socket in use or over time. It will be understood that the connecting cable may be an assembly of cables including one or more power cables and one or more data/control cables. Alternatively all the necessary connecting wires may be accommodated within a single cable as shown in this example. It will also be understood that the plug and socket arrangement could be the other way round, with the socket or female parts being on the end of the connecting cable and the plugs, or male parts, being integrated in the light emitting portion and the power/control portion as required.

There are several variations of this plug and socket arrangement that might be adopted by a person skilled in the art. For example, the connecting cable could have a plug at one end and a socket at the other end, with a corresponding socket and plug in the respective portions. Or the connecting cable may be permanently connected at one end to either the light emitting portion or the power/control portion, with a plug or socket at the other end of the connecting cable.

The end result of these various connecting cable arrangements is such that the power/control portion and the light emitting portion can be completely separated from each other in a disassembled configuration and attached together in an assembled configuration as and when required. By constructing the luminaire assembly in two separate parts, and by providing a pluggable, and therefore unpluggable, cable connection between those two parts the power/control portion can be detached completely from the light emitting portion. This provides a number of advantages, especially a major cost saving advantage in terms of inventory management that has not been possible before, and reduces the number of Stock Keeping Units (SKU) required to stock a complete range. This is because different light emitting portions and different power/control portions can be paired together in any desired 'mix and match' combination to meet the specific needs of the customer, dramatically reducing the number SKUs required to be held.

Separating the power/control portion of the downlight from the light emitting portion in use also serves to reduce the overall temperature of the product as the two main heat sources are separated and not contributing to one another and therefore the total running temperature of the product is reduced. The result of this new design is a downlight, and particularly a fire rated downlight, which has an attached driver which can also be taken off to reduce the overall height of the fitting. Fire rating may be achieved by the strategic placement of intumescent material within the collar region 21, such as an annular ring of intumescent material (not shown). This intumescent material is adapted to expand inside the light emitting portion in the event of a fire. This provides the required level of fire protection by preventing any fire from getting beyond the collar region 21 of the light emitting portion.

This design allows the product to be covered with insulation in a ceiling void without a separate insulation guard/cover being required to keep the insulation away from the product. This has the advantage that loose or “blown in” insulation (commonly used in France and the USA) may be used around the product instead of the usual rolls of fibreglass or Rockwool (RTM) insulation. The cover or end cap 15 at the top of the power/control portion therefore serves as an insulation cover when the downlight is installed in its “out of the box” assembled configuration (i.e. both parts together).

There are various ways in which the connecting cable connecting the light emitting portion to the power/control portion may be accommodated in the space provided. A chamber 40, on the back of the light emitting portion, can be designed to accommodate the connection cable 42. Cable clips may be provided, along with directional arrows, (not shown) so that the cable can be clipped snugly into the chamber in a pre-determined route when the two portions are connected together in their assembled configuration. Alternatively a simple channel and clip arrangement may be provided (not shown). When the two portions are clipped together in the assembled configuration the connecting cable is held in a channel on the underside of the power/control portion. Any excess cable can be accommodated in a corresponding channel on the top of the light emitting portion. When the two portions are clipped together in the assembled configuration the channels are preferably substantially aligned with each other.

Clips 60, 61 are provided to latch the light emitting portion to the power/control portion. In this example a clip and latch arrangement comprising a lever which when pressed releases a latch from engaging with a shoulder 60B (not shown), 61B on the power/control portion. However, these attachment means can take a wide variety of forms and any suitable type of attachment means can be used, including a twist and lock mechanism.

In practice, when a shallow ceiling void is encountered, once an electrical connection to a suitable power supply has been made to the power/control portion, the two portions of the downlight assembly are disconnected from each other. In this disassembled configuration the power/control portion is inserted through the aperture in the ceiling first, and placed to one side of the aperture. A fixing ring assembly (see below) is attached to the front of the light emitting portion, which is then inserted into the aperture in the usual fashion making sure that the springs 14 do not foul the nearby power/control portion. A suitable decorative bezel is then fitted to the front of the fixing ring as required and the installation is complete. The connecting cable 42 is designed to be of sufficient length that the power/control portion may be placed separately alongside the light emitting portion when the luminaire assembly is installed in a surface is a disassembled configuration. A new type of fixing ring assembly 128 is shown in Figure 6B. This fixing ring arrangement is applicable to a wide range of luminaire assemblies and downlights, not just the particular downlight assemblies described above. The fixing ring assembly comprises a substantially tubular body 129 adapted to fit inside the collar 121 of a light emitting portion. The tubular body 129 is preferably held in engagement with collar 121 by a 'twist and lock' mechanism 130 and 131 (131 is not shown) that engages with lugs 138 or other deformations (only one of which is shown) on the inside of collar 121. It should be noted that the pin 138 is long enough to accommodate both the fixing ring assembly and a bezel or other decorative accessory designed to cover an outwardly extending flange 121 A, attached to the end of tubular body 129, which forms a flange around the end of the collar 121 once the fixing ring assembly is attached to the collar.

Importantly at least one fixing means is provided and adapted to ensure that once the collar and the fixing ring are fully engaged the tubular body portion of the fixing ring assembly becomes non-detachable from the collar. That is to say, the fixing ring cannot be rotated further in the direction of attachment, and cannot be rotated in the reverse direction required to detach it. One method by which this non- detachable arrangement can be achieved is by the fixing ring assembly incorporating resiliently deformable lugs 132, 133 (only 132 is shown in Figure 6B), resiliently biased to extend outwardly from the tubular body. Corresponding recesses 134, 135 are provided in the collar 121, adapted to accommodate the lugs when the collar and the fixing ring are assembled and rotated to the full extent allowed by the twist and lock mechanism. The recesses may advantageously take the form of apertures. Preferably the lugs are located on the fixing ring and the corresponding recesses/apertures are located in the collar as shown in Figure 6, although the opposite arrangement is also possible. Once the fixing ring assembly has been rotated to the extent that one or both lugs are located in a corresponding recess, rotation of the fixing ring in either direction is prevented and the two components become substantially non-detachable.

In the case of a fire rated luminaire assembly the fixing ring assembly is preferably made from a thin sheet metal such as mild steel sheet that will withstand the conditions of the UK Fire Rating tests in the appropriate section of BS 476. This provides sufficient flexibility in the lugs that they can flex back substantially into the plane of the tubular portion 129 when the fixing ring assembly is offered up to the inside of the collar 121. This arrangement works particularly well if the lugs depend downwards in a direction from the top of tubular portion 129 towards the flange 121A. The end edge of collar 121 meets the narrowest part of the lug as the two parts are pushed together, flexing the lugs as the fixing ring assembly is pushed fully into the collar 121. In this example it will be an edge of the lug that contacts the edge of a corresponding recess.

Where the downlight is not required to be fire rated, other materials, such as plastics materials or a lower melting metal such as aluminium, can be used in the construction of the fixing ring assembly.

In summary it will be appreciated that this arrangement prevents any subsequent rotation of the tubular portion in an anticlockwise direction with respect to the collar 121. In a similar manner, the twist and lock mechanism prevents any rotation in a clockwise direction. In this way the collar 121 and thus the light emitting portion, and the fixing ring assembly once assembled become a unitary component and are substantially non-detachable one from another. It should also be noted that this is only one example of a number of ways and fixing means that can be used to make the fixing ring assembly non-detachable from a collar, once assembled. It is intended that this disclosure extends to include and encompass other mechanical equivalents.

The fixing ring assembly described above provides a means for attaching a number of decorative finishing accessories to the outside face of the luminaire assembly such a decorative bezels and the like. The fixing ring assembly itself may also take a variety of forms, such as a baffle attachment or a trimless attachment. All of these attachments incorporate a fixing means of the type described above and become substantially non-detachable from the light emitting portion or collar 121 once assembled.

Claims

1. A downlight assembly comprising a light emitting portion and a power/control portion, wherein the light emitting portion comprises a first housing and the power/control portion comprises a second housing, the housings being attachable to and detachable from each other in use by means of an attachment means comprising a latch type arrangement, the downlight assembly further comprising a pluggable connecting cable adapted to form an electrical/data connection between the light emitting portion and the power/control portion, such that the power/control portion and the light emitting portion can be completely separated from each other in a disassembled configuration and attached together in an assembled configuration.

2. A downlight assembly according to Claim 1 wherein the light emitting portion and/or the power/control portion incorporate a plug socket and the pluggable connecting cable is configured to be inserted into the plug socket in the light emitting portion or the power/control portion, or both.

3. A downlight assembly according to Claim 2 wherein both the light emitting portion and the power/control portion incorporate a plug socket and the connecting cable incorporates a corresponding plug at each end.

4. A downlight assembly according to any preceding claim wherein the latch type mechanism comprises a resiliently deformable latch mechanism.

5. A downlight assembly according to any preceding claim wherein the connecting cable is housed substantially within the housings when the downlight assembly is in its assembled configuration.

6. A downlight assembly according to any preceding claim wherein the connecting cable is housed within a cable chamber.

7. A downlight assembly according to Claim 5 or Claim 6 further comprising at least one cable tidy clip adapted to arrange the connecting cable within the downlight assembly.

8. A downlight assembly according to Claim 5, Claim 6 or Claim 7 wherein the first housing and/or the second housing further comprise a channel adapted to accommodate part of the connecting cable when the downlight assembly is in its assembled configuration.

9. A downlight assembly according to any preceding claim wherein the light emitting portion comprises a collar having a front side and a rear side with an inwardly directed flange on the rear side, a solid state lighting element closing off the rear side of the collar, and a heat sink in direct contact with the solid state lighting element.

10. A downlight assembly according to Claim 9 wherein the solid state lighting element comprises a PCB.

11. A downlight assembly according to Claim 10 wherein the PCB is formed from a material that melts below 900°.

12. A downlight assembly according to any preceding claim wherein the light emitting portion is fire resistant.

13. A downlight assembly according to Claim 12 wherein the light emitting portion further comprises intumescent material adapted to expand inside the light emitting portion in the event of a fire.

14. A downlight assembly according to any preceding claim wherein the connecting cable between the light emitting portion and the power/control portion is of sufficient length that the power/control portion may be placed separately alongside the light emitting portion when the downlight assembly is installed in a surface is a disassembled configuration.

15. A downlight assembly according to any preceding claim wherein said first housing comprising a substantially tubular body portion adapted to accommodate a lamp, and the downlight assembly further comprises a separate fixing ring, attachable to the first housing in order to form a flange at the front of the first housing, and fixing means adapted to secure the fixing ring to the tubular body portion.

16. A downlight assembly according to Claim 15 wherein once attached to the tubular body portion the fixing ring becomes non-detachable.

17. A downlight assembly according to Claim 15 or Claim 16 wherein the fixing means incorporates a resiliently deformable lug and a corresponding recess adapted to accommodate the lug when the first housing and fixing ring are assembled.

18. A downlight assembly according to Claim 17 wherein the lug is located on the fixing ring and the corresponding recess is located in the first housing.

19. A downlight assembly according to Claim 17 or Claim 18 wherein, once the lug is located in the recess, rotation of the fixing ring in either direction is prevented.

20. A downlight assembly to any of Claims 17 to 19 inclusive wherein the recess takes the form of an aperture.

21. A method of installing a downlight assembly in a surface including the steps of> a) Providing a downlight assembly according to any of Claims 1 to 20 inclusive; b) Making an aperture in the surface in which the downlight assembly is to be installed; c) Making electrical and control connections to the power/control portion of the downlight assembly as necessary; d) Disconnecting the two portions of the downlight assembly whilst retaining the electrical connections between the light emitting portion and the power/control portion; e) Inserting the power/control portion through the aperture and placing to one side of the aperture; f) Fixing a fixing ring to the light emitting portion; g) Inserting the light emitting portion into the aperture, making sure that any springs do not foul the nearby power/control portion.