GB2452922A

GB2452922A - Adjustable lighting device

Info

Publication number: GB2452922A
Application number: GB0718195A
Authority: GB
Inventors: Bernard Cook
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-09-19
Filing date: 2007-09-19
Publication date: 2009-03-25
Also published as: GB0718195D0

Abstract

A lighting device 10 comprises a light emitting element 12 that transmits light through a directing member 14, a ball-joint 16, and through a second light directing member 18 having a light emitting surface 42, and which is provided on the ball joint 16. The light emitting surface 42 is thereby angularly displaceable via the ball-joint 16. The ball-joint may be transparent, comprise a ball and socket and be mounted at the apex of transparent cone-shaped light guides 14,18 which can opaque surfaces 26,44. The light emitting element 12 can comprise a bulb, a LED or a cluster of LEDs and a heatsink 20. The lighting device may have a housing 30 and be recessed in a ceiling, and provides a spot light source whose angle is adjustable while the lamp is energised.

Description

LIGHTING DEVICE

This invention relates to a lighting device, and more particularly to a lighting device with an angularly adjustable light ernitahie surface.

There is a vast array of lighting devices on the market. It is often a requirement that the direction of the emitted light beam must he changed. However, frequently the adjustable portion becomes extremely hot to the touch, making angular adjustment whilst the light is on difficult. Although of particular relevance to lighting devices which use filament bulbs, this difficulty also occurs, although to a lesser degree, with other types of bulbs, such as light emitting diodes (LEDs) and gas-discharge bulbs.

It is therefore an object of the invention to provide an angularly adjustable lighting device which is not only inexpensive to manufacture, but which spaced the bulb sufficiently from the angularly adjustable portion so that adjustment can take place whilst the device is cncrgiscd.

According to the present invention, there is provided a lighting device comprising a light emitting clement, a first light directing member on or adjacent to which the light emitting clement is mounted, a hall-joint through which light is transmissible and which is in light-transmissible communication with the first light directing member, and a second light directing member having a light emitahle surface and which is provided on the hall-joint in light-transmissible communication therewith, the light emitable surface being angularly displaceable via the hall-joint.

Preferable and/or optional features of the invention are set forth in claims 2 to 12, inclusive.

The present invention will now he more particularly described, by way of example only, with reference to the sole accompanying drawing, which diagrammatically shows an side elevational view of a lighting device, in accordance with the invention.

Referring to Figure I, there is shown a lighting device 10 which comprises a light emitting element 12, a first light directing member 14, a ball-joint 16, and a second light directing member 18.

The light emitting element 12 is at least one filament bulb, light emitting diode (LED), or gas-discharge bulb. Preferably, an LED or cluster of LEDs is utilised, due to the low running costs and relatively low heat output.

The or each light emitting clement 12 is mounted on a heat sink 20 to further dissipate generated heat.

To direct a light beam emitted by the or each light emitting element 1 2, the first light directing member 14 is provided. In this embodiment, the first light directing member 14 is an inverted cone formed of transparent material. The material can he plastics, such as acrylic, or glass. An opening 22 is formed in the base 24 of the cone of the first light directing member 14 to accept the or each light emitting element 12. The light emitting element 1 2 is either mounted in direct contact with the first light directing member 14, or is slightly spaced therefrom to further reduce heat transmission.

The first light directing member 14 may also include an opaque exterior surface 26 to prevent light from escaping. As such, a light transmission path is provided through the first light directing member 14 from the base 24 to the apex 28.

The light emitting clement 12 and any accompanying control circuitry, heat sink 20, and first light directing member 14 arc conveniently housed in a lighting housing 30. The housing 30, and thus the interior components, can be of any required size, hut for example may he dimensioned to fit within the depth of a floor joist, thus allowing positioning in a ceiling. Alternatively, the housing 30 can be placed into a wall, or can be dimensioned to fit within the thickness of, or pass through, a shelf, thus providing an up-or down-lighting effect.

The hall-joint 16 is transparent. A transparent socket 32 of the ball-joint 16 is formed at the apex 28 of the first light directing member 14 and is dimensioned to receive a transparent ball 34 of the ball-joint as a tight push-or snap-fit. The first light directing member 14 and the socket 32 arc formed as one-piece, hut can he formed separately and connected. The lighting housing 30 has an opening 36 on one surface to allow the ball 34 of the ball-joint 16 to access the socket 32, and also a front plate 37 which is fixed to the housing 30. The front plate 37 is solid and can be transparent, translucent or opaque.

The front plate 37 may be attached to or separate of the first light-directing member 14.

The ball 34 of the ball-joint 16 projects through the front plate 37 to connect with the socket 32. The socket 32 is positioned directly at the opening 36 to allow maximum possible angulation of the hall 34.

The second light directing member 18 is also cone-shaped, and is formed with the ball 34 of the hall-joint 16 at its apex 38. The second light directing member 1 8 and balI 34 are formed as one-piece, hut can he formed separately and then connected.

Similarly to the first light directing member 14, the second light directing member 18 is formed of transparent material, such as plastics or glass, and its base 40 forms a light emitahle surface 42. The conical exterior surface 44 is opaque, thus providing a light- transmission path through the second light directing member 18 from the hall 34 at the apex 38 to the light emitahie surface 42 at the base 40.

The hall 34 of the ball-joint 16, when located in the socket 32, allows the second light IS directing member 18 to he angularly oriented so that the light ernitable surface 42 is positionable in almost any direction. The second light directing member 18 can he moved through 360 degrees in a horizontal plane, and substantially 180 degrees in a vertical plane.

In use, the or each cnergised light emitting element 12 emits a light beam into the first light directing member 14. Due to the inverted conical shape of the first light directing member 14. the light energy is directed or funnelled to the socket 32 of the haIl-joint 16.

It passes from the socket 32 to the transparent ball 34, and then into the second light directing member 1 8. Due to the conical shape and the opaque exterior surface 44, the light energy is directed to the light emitable surface 42, at which point it leaves the lighting device 10.

Since the second light directing member 18 is spaced from the light emitting device, and since a heat sink 20 is utilised, very little, if any, heating of the second light directing member 18 occurs. This allows a user to conveniently and safely orientate the light emitable surface 42, even when the or each light emitting element 12 has been energised for some considerable time.

By funnelling the light energy emitted by the or each light emitting element, very little wastage occurs.

The use of a transparent hall-joint significantly reduces the number of parts, when compared to traditional spot lights. Manufacture and assembly is thus substantially IS simplified and more cost-effective.

Although the first light directing member is described as being conical, other shapes are feasible. For example, for larger applications, the first light directing member can be cylindrical or columnar.

Light energy transmission from the light emitting element to the socket of the ball joint may operate on the principle of fibre optics, utilising total internal reflection. Similarly, light energy transmission from the ball to the light einitablc surfiice of the second light directing member may also utilise total internal reflection. In either or both of these cases, the opaque exterior surface may be dispensed with.

The hall-joint can he formed separately of the first and second light directing members.

S

The second light directing member can he interchangeable or selectable based on requirements, thereby allowing an end-user to choose a design of their liking. As such, the second light directing member need not be conical, hut may he cylindrical, columnar or of any shape, such as serpentine or arcuate.

The embodiments described above arc given by way of examples only, and various other modifications will he apparent to persons skilled in the art without departing from the scope of the invention, as defined by the appended claims.

Claims

1. A lighting device comprising a light emitting clement, a first light directing member on or adjacent to which the light emitting clement is mounted, a ball-joint through which light is transmissible and which is in light-transmissible communication with the first light directing member, and a second light directing member having a light ernitable surface and which is provided on the ball-joint in light-transmissible communication therewith, the light emitable surface being angularly displaceable via the ball-joint.

ID

2. A lighting device as claimed in claim 1. wherein the ball-joint is transparent.

3. A lighting device as claimed in claim I or claim 2, wherein the ball-joint comprises a ball and socket, the socket being provided on the first light directing member, and the ball being provided on the second light directing member.

4. A lighting device as claimed in any one of the preceding claims, wherein the first light directing member is cone-shaped, the ball-joint being provided at the apex and the light emitting element being provided at or adjacent to the base.

5. A lighting device as claimed in any one of the preceding claims, wherein the first light directing member is transparent.

6. A lighting device as claimed in claim 5, wherein the first light directing member includes an opaque exterior surface.

7. A lighting device as claimed in any one of the preceding claims, wherein the second light directing member is cone-shaped, the hall-joint being provided at the apex and the light emitable surface being at least part of the base.

8. A lighting device as claimed in any one of the preceding claims, wherein the second light directing member is transparent.

9. A lighting device as claimed in claim 8. wherein the second light directing member includes an opaque exterior surface.

10. A lighting device as claimed in any one of the preceding claims, further IS comprising a heat sink on which the light emitting clement is mounted.

II. A lighting device as claimed in any one of the preceding claims, wherein the light emitting device is at least one light emitting diode (LED).

12. A lighting device as claimed in any one of the preceding claims, further comprising a lighting housing, the light emitting element and the first light directing member being housed in the housing, and the second light directing member being external of the housing.

13. A lighting device substantially as hereinhefore described with reference to the accompanying drawing.