GB2219068A - Lighting unit - Google Patents

Abstract

A lighting unit includes a luminaire 12 comprising a stack of substantially identical hollow generally frustro-conical opaque elements 14 mounted so that each is downwardly, outwardly flaring with one above another and with the uppermost edge of each element at or above the level of the lowermost edge of the next such element. The uppermost edge of each frustro-conical element is said to be located within the lowermost part of the element next thereabove and the wider end of each such element may have a rim 20 extending substantially horizontally. The elements of the luminaire are separable and are held spaced apart supported on a body member by a rods 22 to which each element is attached and which are themselves are releasably attached to the body member. <IMAGE>

Description

LIGHTING UNITS DESCRIPTION The invention relates to lighting units, in particular lighting units for providing ambient, nondirected lighting in domestic and commercial environments.

The effective lighting of the interiors of buildings - in particular used for domestic living accomodation or as a workplaces - requires that, in general, two different lighting needs must be considered.

The first of these is to enable sufficient lighting at specific locations to enable a task to be performed (e.g. sewing, reading) easily by a person, and the second is to provide a level of ambient or background lighting in which people may comfortably move around and perform tasks not requiring a high level of visual acuity.

Traditionally these two needs have been met by providing an ambient light level which is sufficiently high to enable most tasks to be'easily carried out by making use overhead lighting - possibly mounted above or behind diffusers, any necessary further lighting being provided by standard lamps or table lamps at (the height and/or angle of which may be adjustable) at locations where additional lighting is needed.

The traditional approach has led to problems in recent times most notably with the increased use of televisions in the home and computer and other video screens in commercial environments. The traditional solution of providing a high ambient light level leads to light reflections from reflective surfaces in turn giving rise to discomfort for individuals and making the images on television and other video screens difficult for a viewer to discern.

Attempts to overcome this problem have included generally the provision of non-reflective surfaces on desks and other furniture and the use of so-called anti-glare screens which one may place over a television or video screen being viewed. Other proposals have included and the use of so-called uplighters (lamps which direct light upwardly onto a ceiling such that the light is reflected and diffused thereby).

The use of anti-glare screens has the disadvantages of reducing the amount of light coming from the television or video screen being viewed and therefore itself making images thereon difficult for a viewer to discern. The use of uplighters has the disadvantage that the ambient light level provided is highly dependant upon both the height of the ceiling above the uplighter and the reflectance of that ceiling - simply moving the uplighter from one room to another may unacceptably alter the level of illumination that it provides.

Objects of this invention include the provision of a lighting unit which overcomes these disadvantages and provides an even level of diffused light.

In one aspect the invention provides a lighting unit comprising a body member supporting a lamp and a luminaire, which luminaire comprises a plurality of substantially identical hollow generally frustro-conical non-transparent elements mounted in use so that each is downwardly, outwardly flaring with one above another and such that the uppermost edge of each element is at a level which is at or above the level of the lowermost edge of the next succeeding element of the luminaire.

In this specification and in the claims annexed hereto the term luminaire is to be taken as that portion of a lighting unit designed and adapted to distribute the light provided by the lighting unit when it is operational.

Preferably the uppermost edge of each element is located within the lowermost part of the element next thereabove.

The frustro-conical elements of the luminaire are preferably opaque.

Each frustro-conical element may includes a rim portion which in use extends substantially horizontally.

The uppermost frustro-conical element of the luminaire is desirably closed by a reflecting element which is conical and tapers downwardly.

The taper angle of the conical reflecting element may lie in the range 200 to 500.

In this specification and in the claims annexed hereto the taper angle of a conical reflector element is to be taken as the angle by which the wall of the conical reflector diverges from the normal to the plane including it's wider end in running from that end to it's other end.

Desirably the flare angle of the frustro-conical 0 elements is substantially equal to 52 and the taper angle of the conical reflecting element is in the range 280 to 0 43 In this specification and in the claims annexed hereto the term flare angle of a frustro-conical element is to be taken as the angle by which the wall of the frustroconical element diverge from the normal to the plane including it's narrower end in running from that end to it's wider end.

The luminaire may further include a generally circular in section diffuser means axially aligned with and extending between the frustro-conical elements thereof, the outer diameter of the diffuser means being equal to or less than the smallest diameter aperture in each of said elements. The diffuser means may comprise a hollow cylindrical translucent member mounted to extend the length of the luminaire.

The frustro-conical elements of the luminaire are desirably separable one from the other, the frustro-conical elements being held spaced apart and supported on the body member by a plurality of rod members to which each element is attached and which are themselves are releasably attached to the body member.

The body member preferably supports said lamp within or below the lowermost frustro-conical element of the luminaire, such that an observer cannot directly see the lamp.

The body member may support a reflector element beneath the lamp.

Desirably the body member comprises a vertically oriented hollow cylindrical member of opaque material, the luminaire being mounted at the uppermost end thereof.

The length of the body member may be variable.

The lowermost end of the body member may be apertured and the body member support therein electrical fan means enabling air to be drawn along the length thereof.

Additionally, the body member may support therein electrical air heating and/or cooling means enabling air therein to be heated and/or cooled.

The body member may be connectable to an external supply of heated and/or cooled air.

In a second aspect the invention provides an air heating and/or cooling system incorporating a lighting unit having features as noted above.

Other aspects, features and advantages of the invention will become apparent from the following description of embodiments of the invention now made with reference to the accompanying drawings, in which: Figure 1 shows a side view of a first lighting unit embodying the invention, Figure 2 shows at A and B respectively a plan view and an enlarged scrap view of part of the lighting shown in Figure 1, Figure 3 is a schematic sectional side view of a modified form of the lighting unit of Figure 1, Figure 4 shows at A, B and C detailed perspective scrap views of the lighting unit of Figure 1, and Figure 5 is a schematic sectional side view of a second lighting unit embodying the invention.

With reference now to the drawings, Figures 1 to 4 illustrate a lighting unit which may be either for use on a table (as a table lamp) or a standing freely on a floor (as a standard lamp).

The lighting unit comprises an elongate circular cylindrical upstanding body member 10 supporting at it's upper end a luminaire 12 comprising a plurality of (in the example shown seven) substantially identical hollow generally frustro-conical non-transparent elements 14 mounted in use so that each is downwardly, outwardly flaring. The frustro-conical elements 14 are mounted axially aligned one above another and such that the uppermost edge 16 of each element 14 is within the lowermost part 18 of the frustro-conical 14 element next thereabove.

The lowermost, wider end 18 of each frustroconical element 14 is provided with a substantially horizontally extending a rim portion 20 as shown.

The frustro-conical elements 14 of the luminaire 12 are separable one from another and are supported on the body member 10 by three equi-spaced rods 22 each of which passes through an aperture in each element 14. The elements 14 are held spaced apart by hollow clyindrical spacers elements 23 carried by the rods 22 and the ends of which are shaped and adapted to bear on the upper and lower surfaces of the outwardly flaring skirt 24 of each element 14 (see Figure 2B). The upper ends 26 (see detail Figure 4A) of the rods 22 pass through connector elements 28 which are wedge shaped and have an edge resting on the skirt 24 of the uppermost frustro-conical element 14 of luminaire 12. The upper ends 26 of rods 22 are threaded and engaged by nuts 30 which, when tightened, bear on the upper - horizontally extending - surfaces 32 of the connectors 28 (see Figure 4A).

The lowermost ends of the rods 22 are received in elongate clamp elements 34 (see detail Figure 4B) bolted onto the sides of the body 10 and spaced therefrom by spacers 36. The bolts 38 carrying the clamp elements 34 pass through holes (not seen in the Figures) in the lower ends of the rods 22 so that the rods are firmly but releasably held on the body member 10.

The luminaire 12 is supported by the rods 22 such that the rim 20 of the lowermost frustro-conical element 14 of the luminaire 12 lies in a plane below that on the top of the body member 10.

The innermost ends of the connector elements 28 support a reflector element 40 which closes the top of the luminaire 12. Reflector element 40 lies in the upper, smaller aperture in the uppermost frustro-conical element 14 of the luminaire 12, is conical and tapers downwardly as shown.

As can be seen from the Figures the body member 10 comprises a vertically oriented hollow cylinder 42 supported on a base plate 44 by three pillars 46. The pillars 46 are joined to the cylinder 42 by pairs of bolts 48 as shown spacer members 50 being provided such that the pillars 46 lie axially in line with the rods 22 and clamp elements 34 thereabove.

The bottom edge of the body 10 is spaced slightly above the base plate 44 and the base plate 44 carries a small plinth 52 the top of which is located at a level above the bottom of the body 10 and may - as shown - carry an electrical fan 54. If provided fan 54 is arranged to draw air into the body member 10 via the gap between it's bottom edge and the base plate 44 and pass that air up the body member 10 to emerge via the luminaire 12.

At it's upper end the body 10 carries on a inner wall (see Figure 3) a combined bracket and lamp holder 56 in which an electrical bulb 58 may be placed as shown.

It is to be noted that the position of the lamp holder 56 is such that the bulb 58 extends above the top edge of the body 10 - that is to say to a level within the lower part 18 of the lowermost frustro-conical element 14 of the luminaire 12 at which it cannot directly be seen by an observer.

The top of one of the pillars 46 (see detail Figure 4C) includes an electrical switch 60 by means of which the bulb 58 may be connected to an electrical supply.

The same switch 60 - or another (not shown) in another of the pillars may be used to control operation of the fan 54.

The elements of the lighting unit may be of any suitable material, however, it is preferred that the body member 10, the frustro-conical elements 14 of luminaire 12, the rods 22, the connector elements 28, the clamp elements 34, the reflector element 40, the base plate 44, the pillars 46 and the plinth 52 are all of polished metal e.g. steel, copper, brass or the like - or combinations of different metals to provide a pleasing appearance.

It will be appreciated that the distribution of light from the lighting unit depends upon the height of the body member, the flare angle Tf of the frustro-conical elements 14 and the taper angle Tc of the conical reflector element 40.

In order to maintain a pleasant appearance for the lighting unit a flare angle Tf of approximately 520 has been selected for the frustro-conical elements 14 and the taper angle Tc of the conical reflecting element preferably lies in the range 350 to 450.

For a lighting unit having an overall height of say five feet the taper angle Tc of the conical reflecting element is substantially equal to 420 .

The bulb may be replaced (if it should fail) by simply removing the bottom ends of the rods 22 from the clamps 34 and lifting the complete luminaire off the body member 10. Similarly, access may be had to the fan 54 by laying the lighting unit on it's side and separating it from the base 44 which carries the fan.

It will be seen that the arrangement described provides a diffuse, generally downwardly directed light providing ambient lighting with reduced levels of glare and without need for reliance upon any surface outside the lighting unit (e.g. a ceiling). It will also be seen that the arrangement described may be used to provide circulation of air in a room in which the lighting unit is placed - when the fan 54 is activated cooler, denser air may be drawn from the lower parts of the room, passed up the body member 10 and out into the higher parts of the room.

It will be appreciated that the lighting unit so far described may be modified without departing from the scope of the invention. One of these is illustrated in Figure 3 which shows the body member 10 of the lighting unit shown in Figure 3 to be two parts 62 and 64 - the lower end of the upper part 62 being of reduced diameter and fitting within the upper end of the lower part 64. Thus the two parts are movable relative to one another to alter the overall length of the body member 10. The two parts 62 and 64 may be held in in any relative desired position in any suitable way - e.g. by the one friction fitting within the other or by the use of lock bolts 66 which pass through holes in the wall of the part 64 and elongated slots in the wall of the part 62 such as indicated at 68.

The body member 10 may house in addition to the fan 54 and bulb 58 air heating and/or cooling units of known form such that air driven-up the body member 10 by the fan 54 is heated and/or cooled before it is passed back into the room.

Although the lighting unit has been described as including a fan 54 mounted on plinth 52 it will be appreciated that if desired this fan may be mounted on the inner wall of the body member 10 at the same or a higher position therein than is shown and that the fan 54 (and plinth 52) may be omitted if desired.

Figure 5 illustrates another lighting unit embodying the invention which is for floor mounting.

Those parts of this embodiment which perform the same function and have the same configuration as the parts of the lighting unit shown in Figures 1 to 4 are given the same reference numerals and will not further be described.

It is preferred that the materials of the lighting unit now to be described be the same as described with referrence to the earlier Figures.

It will be appreciated that in this arrangement the body member 10 - which is not intended to be as readily moved from place to place as the table and free standing lighting units of Figures 1 to 4 is larger in size being both taller and wider than the body members of those lighting units.

For aesthetic reasons the flare angle Tf of the frustro-conical elements 14 has been retained substantially 0 52 , however, as the lighting unit is taller (say six to eight feet tall) overall than than the lighting units already described the conical reflector element 40 has a taper angle Tc which smaller (preferably in the range 250 to 350 and thus acts to direct more light downwardly than is the case with the lighting units decribed with reference to Figures 1 to 4.For a lighting unit say seven feet tall overall the taper angle Tc of the conical reflecting element is preferably substantially equal to 280 Another difference between the lighting unit now described and that shown in the earlier Figures is that the luminaire 12 includes a diffuser 70 comprising a generally circular in section translucent glass or plastics material cylinder which is axially aligned with and extends upwardly through the smaller apertures in the uppermost edges of the frustro-conical elements 14. Diffuser 70 is held suspended in position being connected in any suitable way at its upper edge to the connector element 28.

The use of diffuser 70 enables a more powerful lamp 58 to be used in the lighting unit.

Yet another difference between the lighting unit now described and that shown in the earlier Figures is that the body member 10 is provided with a parabolic reflector 72 located in the body member 10 just below the bulb 58 to ensure more light from the bulb passes up and into the luminaire 12.

The lighting unit of this embodiment is mounted directly on a base plate 44 which is fixed directly to a floor 74 on which the lighting unit is to stand and houses a larger fan 54 than is used in the lighting units described with reference to Figures 1 to 4. Again, the unit of Figure 5 is provided with an air heating and/or cooling unit 76 and a honeycomb grill 78 of known form the "cells" of which are axially aligned with the body member 10 to produce laminar air flow which may be heated and/or cooled up the body member 10.

Heated and/or cooled air driven up the body member by the fan 54 passes - as in the lighting units described and with reference to the earlier Figures out of the lighting unit via the luminaire - but may also pass out of the body member at a position intermediate it's length via apertures 80 partially hidden by frustro - conical elements 82 similar to the elements 14 of luminaire 12 surrounding the body member 10 and supported (in a manner similar to that of the elements 14) on rods 84 supported on the body member 10 by the clamps 34 wich support the rods 22.

The lighting unit may be connected via apertures in the base plate 44 and floor 74 upon which it stands to parts of a an air heating and/or cooling system shown dotted at 86 in Figure 5, and thus form part of for example an air conditioning system for the building in which it is located.

If such be the case the air heating and/or cooling unit 76 may be omitted from the body member 10.

As before the bulb may be replaced by simply removing the bottom ends of the rods 22 from the clamps 34 and lifting the complete luminaire off the body member 10.

Access may be had to the fan 54 and heating/cooling elements 76 via access doors (not shown) or by providing that the upper part of the body member may be removed from the lower part.

It will be seen once again that the arrangement described with reference to Figure 5 provides a diffuse, generally downwardly directed light providing ambient lighting with reduced levels of glare and without need for reliance upon surfaces outside the unit, which may be used to provide circulation of heated and/or cooled air in a room in which the lighting unit is placed and which may be connected to form part of an air conditioning system.

To one skilled in the art of this invention it will be appreciated that many variations may be made to the described arrangements without departing from the scope of the invention, some of which are now mentioned.

The particular way on which the luminaire is formed and supported on the body member may be varied - desirably providing that the luminaire retains the particularly described disposition of elements 14 and 40. If desired, however, the conical reflector element may be replaced with another having a different form (e.g. flat, rounded concave or rounded convex) or may in certain circumstances be omitted altogether - to provide for uplighting with light from the unit being reflected from a ceiling above the unit. The number of rods which are used to support the luminaire may be increased if desired.

The luminaire may be provided as a single, integral unit incorporating the diffuser, alternatively the diffuser may comprise a number of separate short cylindrical rings extending between adjacent pairs of frustro-conical elements 14 and held in position by the action of the rods (or any other suitable means).

Again, although described with a single bulb it will be appreciated that light in the lighting unit may be provided by a number of bulbs (perhaps of different colours and separately switchable on and off) providing none of them is directly visible to an observer.

Whilst it is considered desirable that the parts of the lighting unit be of metal it will be appreciated that any suitable material may be used for it's construction.

Finally, although the flare angle of the frustroconical elements of the luminaire is the same in both the described embodiments it will be appreciated that this angle may be varied as desired (together with the taper angle of the conical reflector element) to vary the pattern of light output from the lighting unit.

Claims (22)

1. A lighting unit comprising a body member supporting a lamp and a luminaire, which luminaire comprises a plurality of substantially identical hollow generally frustro-conical non-transparent elements mounted in use so that each is downwardly, outwardly flaring with one above another and such that the uppermost edge of each frustro-conical element is at a level which is at or above the level of the lowermost edge of the next succeeding frustro-conical element of the luminaire.

2. A unit as claimed in Claim 1, wherein uppermost edge of each frustro-conical element is located within the lowermost part of the element next thereabove.

3. A unit as claimed in Claim 1 or Claim 2, wherein the frustro-conical elements of the luminaire are opaque.

4. A unit as claimed in any one of claims 1, 2 and 3, wherein the wherein the wider end of each frustro-conical element includes a rim portion which in use extends substantially horizontally.

5. A unit as claimed in Claim 2 and either of claims 3 and 4, wherein the uppermost part of the uppermost frustroconical element of the luminaire is closed by a reflecting element which is conical and tapers downwardly.

6. A unit as claimed in Claim 6, wherein the taper angle as herein defined of the conical reflecting element lies in the range 200 to 500.

7. A unit as claimed in Claim 5 and Claim 6, wherein the flare angle as herein defined of the frustro-conical 0 elements is substantially equal to 52 and the taper angle of the conical reflecting element is in the range 280 to 0 43

8. A unit as claimed any one of claims 1 to 7, wherein the luminaire further includes generally circular in section diffuser means axially aligned with and extending between the frustro-conical elements thereof, the outer diameter of the diffuser means being equal to or less than the smallest diameter aperture in each of said frustro-conical elements.

9. A unit as claimed claims 8, wherein the diffuser means comprises a hollow cylindrical translucent member mounted to extend the length of the luminaire.

10. A unit as claimed in any one of claims 1 to 9, wherein the frustro-conical elements of the luminaire are separable one from the other, the frustro-conical elements being held spaced apart and supported on the body member by a plurality of rod members to which each frustro-conical element is attached and which are themselves are releasably attached to the body member.

11. A unit as claimed any one of claim 1 to 10, wherein the body member supports said lamp within or below the lowermost frustro-conical element of the luminaire, such that an observer cannot directly see the lamp.

12. A unit as claimed claim 11, wherein the body member supports a reflector element beneath the lamp.

13. A unit as claimed any one of claim 1 to 12, wherein the body member comprises a vertically oriented hollow cylindrical member of opaque material, the luminaire being mounted at the uppermost end thereof.

14. A unit as claimed in claim 13 wherein the length of the body member may be varied.

15. A unit as claimed claim 13 or claim 14, wherein the lowermost end of the body member is apertured and the body member supports therein electrical fan means enabling air to be drawn along the length thereof.

16. A unit as claimed claim 15, wherein the body member supports therein electrical air heating and/or cooling means enabling air therein to be heated and/or cooled.

17. A unit as claimed claim 15, wherein the body member includes means enabling is connection to an external supply of heated and/or cooled air.

18. An air heating and/or cooling system incorporating a lighting unit as claimed in Claim 17.

19. A lighting unit as claimed in claim 1 and having a luminaire substantially as herein described with reference to accompanying drawings.

20. A lighting unit as claimed in claim 1 and substantially as herein described with reference to Figures 1, 3 and 4 of the accompanying drawings.

21. A lighting unit as claimed in claim 1 and substantially as herein described with reference to Figures 2, 3 and 4 of the accompanying drawings.

22. A lighting unit as claimed in claim 1 and substantially as herein described with reference to Figure 5 of the accompanying drawings.