GB2503732A

GB2503732A - Luminaire diffuser arrangement

Info

Publication number: GB2503732A
Application number: GB201212059A
Authority: GB
Inventors: Michael Allcock
Original assignee: FW Thorpe PLC
Current assignee: FW Thorpe PLC
Priority date: 2012-07-06
Filing date: 2012-07-06
Publication date: 2014-01-08
Also published as: GB201212059D0

Abstract

A luminaire has a diffuser 36 mounted in a frame 38 at an edge region 40. The material of the frame 38 is a light diffuser material such as the same material as the diffuser 36. A catch feature 42 is integral with the material of the frame 38 and is deflectable between a position which allows the diffuser to be introduced to the frame 38, and a position which retains the diffuser 36.

Description

lmrjrovements in or relating to luminaires and luminaire diffusers The present invention relates to improvements in or relating to luminaires and luminaire s diffusers.

It is common for lurninaires to include a diffuser arrangement for diffusing the light output of the luminaire, in order to avoid glare, harsh shadows and the like. One style of luminaire is used as part of a suspended ceiling which consists primarily of an array of ic ceiling tiles. The array is interrupted periodically by the omission of a tile and the installation of a luminaire in its place. Previous proposals for this style of luminaire have resulted in diffuser arrangements which adversely affect the aesthetics of the ceiling.

Examples of the present invention provide a luminaire diffuser arrangement comprising: is a diffuser, and a frame to which the diffuser is mounted, in use, wherein at least one catch arrangement is provided to retain the diffuser mounted to the frame, the catch arrangement comprising at least one catch feature which is integral with the material of the frame or the diffuser and is deflectable between a position which allows the diffuser to be introduced to the frame, and a position which retains the diffuser.

The catch feature may be deflected between the positions by engagement with the diffuser as the diffuser is introduced to the frame.

The or each catch feature may be resiliently deflectable to allow the diffuser to be introduced to the frame, and to relax to a position which retains the diffuser. Thö or each catch feature may be a resilient projection. The resilient projection may project from the frame. The projection may be formed of the same material as the frame.

The frame may provide at least one catch feature to retain the diffuser when mounted to the frama The diffuser and an edge region of the frame adjacent to the diffuser, in use, may be s made of substantially the same diffuser material. Substantially the whole of the frame may be made of the diffuser material.

The diffuser and the frame may comprise formations which fit together to place the material of the diffuser and the frame in intimate contact. The fitting formations may be io complementary channel formations which fit together by resting the diffuser against the frame. In use, the fitting formations may prevent movement of the diffuser, relative to the frame, in a direction parallel with the plane of the diffuser. The fitting formations may be made of the same material.

is The diffuser may be a panel framed by the frame. The frame mayprovide at least one support formation against which the diffuser rests for support. The frame may provide a ledge br supporting the diffuser. The ledge may extend around substantially the whole periphery of the diffuser.

Examples of the present invention also provide a luminaire diffuser arrangement comprising: a diffuser, and a frame to which the diffuser is mounted, in use, the frame having an edge region which is adjacent to the diffuser, in use, and wherein the material of the frame, at least in the edge region, is a light diffuser material.

The diffuser may be a panel framed by the frame. The frame may provide at least one support formation on which the diffuser rests for support. The frame may provide a ledge for supporting the diffuser. The ledge may extend around substantially the whole periphery of the diffuser.

The periphery of the diffuser, and the support formation, may comprise formations which fit together to place the diffuser and the support formation in intimate contact. The fitting formations may be complementary channel formations which fit together by resting the diffuser on the frame, to prevent horizontal movement of the diffuser relative S totheframe.

The fitting formations may be made of the same material.

The frame may provide at least one catch to retain the diffuser when mounted to the io frame. The or each catch may be resiliently deflectable to allow the diffuser to move past the catch as the diffuser is introduced to the frame, and to relax to a position which retains the diffuser. The or each catch may be a resilient projection formed of the same material as the frame.

is The diffuser and the edge region of the frame may be made of substantially the same diffuser material. Substantially the whole of the frame may be made of the diffuser material.

Examples of the present invention also provide a luminaire comprising: a housing defining an aperture for light output, and a diffuser mounted on the housing by means of a mounting arrangement, the diffuser, in use, serving to diffuse light leaving the housing through the aperture, the mounting arrangement comprising a frame which lines the aperture and projects from the aperture to an edge at which the diffuser is mounted.

The housing may have formations for supporting the housing, in use, on a supporting framework.

The material of the frame, at least in the edge region, may be a light diffuser material.

Each of these examples of the present invention may incorporate any of the features or any combination of the features of any of the examples set out above.

Examples of the present invention will now be described in more detail, by way of s example only, and with reference to the accompanying drawings, in which: Fig. 1 and Fig. 2 are, respectively, a partial section view (on an enlarged scale) and a plan view from below, illustrating a luminaire arrangement; Fig. 3 and Fig. 4 are, respectively, a partial section view (on an enlarged scale) and a plan view from below, illustrating a luminaire arrangement according to a first example of the invention; Fig. 5 is an isometric view of a diffuser panel and associated frame from the is arrangement of Fig. 3; Fig. 6 is a section through a frame member of the arrangement of Fig. 3; Fig. 7 shows part of the exposed face of the diffuser panel of the arrangement of Fig. 3; and Fig. 8 and Fig. 9 are partial sections at a vertical plane, respectively showing the diffuser panel prior to and after assembly with the frame.

Previous prorosal Fig. 1 and Fig. 2 illustrate a previous proposal of luminaire arrangement 10. This is for use as part of a suspended ceiling. The ceiling is supported by a square lattice of horizontal members 12. generally known as I-bars. The T-bars 12 are arranged in a square lattice and are inverted, so that the crossbar 14 provides two ledges running alongside the leg 16 of the T-bar 12. The leg 16 extends upwardly and is supported from the structure of the building by appropriate support mechanisms (not shown). Most of the openings in the lattice of the T-bars 12 accommodate ceiling tiles 18, the edges of which have rebates 20 to allow the tiles 18 to rest on the ledges provided by the T-bar 12. This provides the ceiling with a neat appearance of square tiles separated by lines defined between the edges of adjacent ceiling tiles 18.

Some of the tiles 18 are omitted and replaced by a luminaire arrangement 10. This has a housing 22 with external flanges 24 to rest on the T-bars 12, generally at 26.

Appropriate light sources (not shown in detail) are accommodated within the housing 22 io to provide light down from the housing 22. A diffuser 28 is provided to defuse the light output of the luminaire 10. The diffuser 28 is in the form of a panel or sheet of diffuser material such as acrylics, polycarbonates or PETO (polyethylene terephtbalate glycol-modified). The material of the diffuser 28 is clouded, obscured or otherwise treated to create diffusion as light passes through.

The diffuser 28 is supported on the housing 22 by means of a metal frame 30 which is secured to the housing 22 and provides a ledge 32 on which the diffuser 28 can rest.

The frame 30 therefore extends into the area of the diffuser 28 and also extends across part of the lower surface of the T-bar 12, to provide an appearance which has no visible gaps, as can be seen from Fig. 2. However, as can also be seen from Fig. 1 and Fig. 2, the dimensions of the exposed area of the diffuser 28 are smaller than the dimensions of the exposed area of neighbouring tiles 18, which are exposed right up to the edge of the T-bar 12. The visible edge 33 of the diffuser 28 is spaced from the T-bar 12 by a distance which is noticeable by eye.

Overview of first example Turning first to Fig. 3, the remaining drawings illustrate a luminaire diffuser arrangement 34 comprising a diffuser 36, and a frame 38 to which the diffuser 36 is mounted, in use.

The frame 38 has an edge region 40 which is adjacent the diffuser 36, in use, as can be seen particularly from Fig. 9. The material of the frame 38, at least in the edge region 40, is a light diffuser material. In particular, the material of the frame 38, at least in the edge region 40, may be the same light diffuser material as the diffuser 36. At least one catch arrangement 42 is provided to retain the diffuser 36 mounted to the frame 38.

The catch arrangement 42 in this example is a catch feature which is integral with the material of the frame 38 and is deflectable between a position which allows the diffuser 36 to be introduced to the frame 38, and a position which retains the diffuser 36.

The term "integral" is used here to mean that the catch features 42 are provided by the same body of material as the other features of the frame 38.

The luminaire 34 further comprises a housing 43 defining an aperture 44 for light output, and the diffuser 36 is mounted on the housing 43 by means of a mounting arrangement 46 to be described. The diffuser 36, in use, serves to diffuse light leaving, the housing 43 through the aperture 44. The mounting arrangement 46 comprises the frame 38 which lines the aperture 44 and projects from the aperture 44 to an edge 40 at which the diffuser 36 is mounted.

Detailed description

In more detail, the housing 43 has peripheral flanges 50 which serve as formations for supporting the housing 43, in use, on the supporting framework of the t-bars 12. This arrangement can be seen in Fig. 3 and allows the aperture 44 to be open across the whole of the gap between the T-bars 12 on opposite sides of the luminaire 34. Thus, the aperture 44 has the same dimensions as the exposed portion of a conventional tile 18.

Appropriate light sources (not illustrated in detail) are housed within the housing 43, above the aperture 44.

The diffuser 36 is a panel or sheet of diffuser material similar to that described above in relation to Fig. 1 and in this example, is a square panel (Fig. 5). The frame 38 is formed around all four sides of the diffuser 36 by four identical frame components, as can be seen from the exploded view of Fig. 5.

The members of the frame 38 have a profile which is illustrated in the section of Fig. 6.

A main wall 52 extends generally upwardly when the frame 38 is installed. The lower edge 40 of the frame 38 has a support formation 54 in the form of a ledge on which the diffuser 36 can rest for support. The ledge 54 extends along the whole length of each member of the frame 38 and thus around the entire periphery of the frame 38, allowing the diffuser 36 to be supported on the ledge 54 around the entire periphery of the diffuser 36. The lower edge of the frame 38 also has a chamfer 55, facing in the opposite direction to the ledge 54.

The ledge 54 has an upper surface which is in the form of a channel section having an upstand 56 separated from the main wall 52 by a channel 58. The profile of the upstand 56 and the channel 58 is complementary to the profile of a groove 60 formed around the periphery of the diffuser 36 (Fig. 7). That is, the lower face of the diffuser 36 has a groove 60 formed near its edge, to receive the upstand 56 and to leave a narrow bead 62 along the extreme edge of the diffuser 36. The diffuser 36 can be rested on the ledge 54 with the upstand 56 received in the groove 60, and with the bead 62 received in the channel 58. Thus, these formations fit tQgether by resting the diffuser 36 onthe ledge 54 of the frame 38. The fitting together of the formations will bring the surfaces of the diffuser 36 and the ledge 54 into intinlate contact and will hold the diffuser 36 against horizontal movement relative to the frame 38.

The walls 52 of the frame 38 are also provided with the catch features 42. Several catch features 42 are spaced along each side of the frame 38. The catch features 42 project away from the inwardly facing surface 66 of the frame 38, over the channel 58.

The catch features 42 are formed of resilient material or are resiliently mounted, in either case allowing the catch features 42 to be resiliently deflectable. Consequently, the diffuser 36 can be assembled to the frame 38 by first introducing the diffuser 36 from above (Fig. 8), moving the diffuser 36 down toward the catch features 42. The

S

diffuser 36 can then be pushed down, past the catch features 42, engaging and deflecting the catch features 42 as the diffuser moves. The groove no and bead 62 engage with the upstand 56 and channel 58 as the diffuser 36 moves past the catch features 42. At the point that the diffuser 36 becomes fully engaged on the ledge 54, the s diffuser 36 moves clear of the catch features 42. The resilience of thecatch features 42 causes them to snap back to their proud position (Fig. 6), resulting in the edge of the diffuser 36 being trapped between the catch features 42 and the ledge 54. This retains the diffuser 36 in the mounted position on the frame 38.

The edge region 40 of the frame 38 is made of substantially the same diffuser material as the diffuser 36. Thus, the fitting formations 56, 58, 60 and 62 are made of the same material, which is diffuser material. The whole of the frame, or substantially the whole of the frame is desirably made of the diffuser material. The catch projections 42 are also made of diffuser material, desirably the same material as the rest of the frame and is of the diffuser. Furthermore, as noted above, the frame 38 lines the aperture 44 and projects from the aperture 44 to the edge 40 at which the diffuser 36 is mounted. The significance of these features can now be described, with particular reference to Fig. 9 and Fig. 3.

When the luminaire 34 is installed on the T-bars 12, with the frame 38 installed in the aperture 44, and the diffuser 36 mounted to the frame 38, as just described, the chamfer 55 is exposed at the edge of the aperture 44, extending down to the lower, f tat face of the ledge 54, which is coplanar with the lower face of the diffuser 36. This outline is substantially or exactly the same as the outline of a tile 18, as can be seen from Fig. 3. Accordingly, when the installed luminaire 34 is viewed from the room below, the tines which are apparent to the eye and are created by the edges of the luminaire 34 are aligned with the corresponding lines created by the edges of tiles 18, creating clean, aesthetically pleasing lines which continue uninterrupted across the whole of the ceiling.

This arises, in part, because the frame 38 is positioned at the extreme edges of the gap between the T-bars 12, and because the outline at the bottom of the frame 38 (particularly the chamfers 55) is substantially or exactly the same as the outline of the tiles 18.

The aesthetic appearance is further improved by the choice of material for the frame 38, and by the manner in which the diffuser 36 and the frame 38 are assembled. Since the diffuser 36 and the frame 38 are made of the same material (a diffuser material), and are assembled by the simple snap fit described above (without the use of any adhesives or additional components), the boundary between the diffuser 36 and the frame 38 is expected to be virtually invisible to the eye, or at least to be unobtrusive. This is io expected to be true whether the luminaire 34 is illuminated or not. The eye will see an item having the same size and form as a tile 18, but made of diffuser material rather than tile material. When the luminaire 34 is illuminated, the diffuser material chosen for the frame 38 allows light to leave the luminaire 34 through the chamfer 55, as well as through the lower face of the diffuser 36. That is, light can leave the luminaire 34 through the whole of the exposed lower face of the frame and diffuser. This, in conjunction with the outline and dimensions of the diffuser and frame being the same as those of the tiles 18, results in the illuminated luminaire 34 having the appearance of an illuminated tile. The visible edges of the diffuser and frame will be at the edges of the T-bars 12.

This contrasts with the arrangement of Fig. 1 and Fig. 2, in which the presence of the frame 30 changes the position of the visible edge 33 of the diffuser 28. The exposed face of the diffuser 28 is smaller than the lower face of a tile 18, causing a visual disturbance of the lines perceived by eye across the ceiling.

Many variations and modifications can be made to the examples described above, without departing from the scope of the present invention. Shapes, sizes and relative shapes and sizes of the various components could be varied. In particular, the visible outline of the diffuser 36 and the frame 38 can be varied to match the outline of tiles 18 alongside which the luminaire 34 is to be installed. Other materials could be used, including other diffuser materials. Acrylic diffuser materials may be considered, but some may be too brittle for the resilient latch function.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

CLAIMS1. A luminaire diffuser arrangement comprising: a diffuser, and a frame to which the diffuser is mounted, in use, wherein at least one catch arrangement is provided to retain the diffuser mounted to the frame, the catch arrangement comprising at least one catch feature which is integral with the material of the frame or the diffuser and is deflectable between a position which allows the diffuser to be introduced to the frame, and a position which retains the diffuser.
2. An arrangement according to claim 1, wherein the catch feature is deflectable between the positions by engagement with the diffuser as the diffuser is introduced to the frame. -15
3. An arrangement according to claim 1 or 2, wherein the or each catch feature is O resiliently deflectable to allow the diffuser to be introduced to the frame, and to relax to a cv) position which retains the diffuser.
4. An arrangement according to any preceding claim, wherein the or each catch feature is a resilient projection.
5. An arrangement according to any preceding claim, wherein the resilient projection projects from the frame.
6. An arrangement according to claim 5, wherein the projection is formed of the same material as the frame.
7. An arrangement according to any preceding claim, wherein the frame provides at least one catch feature to retain the diffuser when mounted to the frame.
8. An arrangement according to any preceding claim, wherein the diffuser and an edge region of the frame adjacent to the diffuser, in use, are made of substantially the same diffuser material.
9. An arrangement according to any preceding claim, wherein substantially the whole of the frame is made of the diffuser material.
10. An arrangement according to any preceding claim, wherein the diffuser and the frame comprise formations which fit together to place the material of the diffuser and the frame in intimate contact.
11. An arrangement according to claim 10, wherein the fitting formations are complementary channel formations which fit together by resting the diffuser against the CV) frame. -15
12. An arrangement according to claim 10 or 11, wherein, in use, the fitting C formations prevent movement of the diffuser, relative to the frame, in a direction parallel with the plane of the diffuser.C
13. An arrangement according to claim 10, 11 or 12, wherein the fitting formations are made of the same material.
14. An arrangement according to any preceding claim, wherein the diffuser is a panel framed by the frame.
15. An arrangement according to any preceding claim, wherein the frame provides at least one support formation against which the diffuser rests for support.
16. An arrangement according to claim 15, wherein the frame provides a ledge for supporting the diffuser.
17. An arrangement according to claim 16, wherein the ledge extends around substantially the whole periphery of the diffuser.
18. A luminaire diffuser arrangement comprising: a diffuser, and a frame to which the diffuser is mounted, in use, the frame having an edge region which is adjacent to the diffuser, in use, and wherein the material of the frame, at least in the edge region, is a light diffuser material.
19. An arrangement according to claim 18, wherein the diffuser is a panel framed by the frame.Cl)
20. An arrangement according to claim 18 or 19, wherein the frame provides at least y-15 one support formation on which the diffuser rests for support. r0
21. An arrangement according to claim 20, wherein the frame provides a ledge for cv) supporting the diffuser.
22. An arrangement according to claim 21, wherein the ledge extends around substantially the whole periphery of the diffuser.
23. An arrangement according to any of claims 18 to 22, wherein the periphery of the diffuser, and the support formation, comprise formations which fit together to place the diffuser and the support formation in intimate contact.
24. An arrangement according to claim 23. wherein the fitting formations are complementary channel formations which fit together by resting the diffuser on the frame, to prevent horizontal movement of the diffuser relative to the frame.
25. An arrangement according to any claims 23 to 24, wherein the fitting formations are made of the same material.
26. An arrangement according to any of claims 18 to 25, wherein the frame provides at least one catch to retain the diffuser when mounted to the frame.
27. An arrangement according to claim 26, wherein the or each catch is resiliently deflectable to allow the diffuser to move past the catch as the diffuser is introduced to the frame, and to relax to a position which retains the diffuser.
28. An arrangement according to claim 26 or 27, wherein the or each catch is a resilient projection formed of the same material as the frame.Cl)
29. An arrangement according to any of claims 18 to 28, wherein the diffuser and the y-15 edge region of the frame are made of substantially the same diffuser material. rO
30. An arrangement according to any of claims 18 to 29, wherein substantially the whole of the frame is made of the diffuser material.
31. A luminaire comprising: a housing defining an aperture for light output, and a diffuser mounted on the housing by means of a mounting arrangement, the diffuser, in use, serving to diffuse light leaving the housing through the aperture, the mounting arrangement comprising a frame which lines the aperture and projects from the aperture to an edge at which the diffuser is mounted.
32. A luminaire according to claim 31, wherein the housing has formations for supporting the housing, in use, on a supporting framework.
33. A luminarie according to claim 31 or 32, wherein the material of the frame, at least in the edge region, is a light diffuser material.
34. A luminarie diffuser arrangement substantially as described above, with reference to any of Figs. 3 to 9.
35. A luminarie substantially as described above, with reference to any of Figs. 3 to 9.
36. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims. C') r Co