AU2007100796B4 - Lights - Google Patents

Description

TITLE: LIGHTS BACKGROUND OF THE INVENTION 1. Field of the Invention THIS INVENTION relates to lights.

The invention particularly relates, but is not limited to, high power, electronic, energy-saving light bulbs.

2. Prior Art With the need to save the world's resources, considerable energy and research has been directed into developing electrical equipment which has a high energy output relative to the energy input.

One major area of research has been in the area of light bulbs where conventional incandescent bulbs, requiring the heating of tungsten filaments to high temperatures, has been replaced by the "low energy" light bulbs where, eg., an 8 watt low energy light bulb may replace a conventional 40 watt incandescent globe.

To date, the limitation has been that the "low energy" light bulbs, which rely on the excitation of phosphors within glass tubes, can only operate at relatively low light outputs, eg., 15 watts or not greater than watts equivalent.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light bulb, of the type having lighting elements comprising phosphors coated glass tubes, which can provide high power outputs, eg., equivalent to 100 watts.

It is a preferred object of the present invention to provide such 140419_1.DOC 00 2 O light bulbs in two parts where the base containing the electronic controls can d be re-used with a plurality of replaceable heads containing the lighting 00 elements.

It is a further preferred object of the present invention to provide alternative forms of the light bulbs to enable either spot or area illumination.

Other preferred objects of the present invention will become Sapparent from the following description.

In a broad aspect, the present invention resides in a light bulb of the type having a plurality of lighting elements, each lighting element comprising at least one phosphor within a transparent tube, the light bulb including: a base, releasably mountable in an electrical socket connectable to an electricity supply; and a detachable head, having a plurality of the lighting elements, the head having first latch means releasably engageable with complementary second latch means on the base and first electrical contacts engageable with complementary second electrical contacts on the base, wherein: the first and second latching means are arranged to provide a bayonet-type connection therebetween, with the first and second electrical contacts being in electrical engagement when the head is operably connected to the base.

Preferably, the base has a metal body portion with an Edison- 208049_1.DOC 00 O Screw (ES) or Bayonet-Cap (BC) spigot at one end releasably engageable in ,.i a the electrical socket and, at the opposite end, a plastics body portion having 00oO the second latch means at an opposite end; and the head has a body member of plastics material having the lighting elements at one end and the first latch means and first electrical contact means at the other end.

Preferably, the electronics, eg., triodes, which control the operation of the light bulb, are mounted on at least one heat sink mounted in, Sand connected to, the metal body portion of the base; and at least one heat dissipation hole is provided in the metal body portion of the base to allow the escape of heat from the interior of the base.

BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which: FIG. 1 illustrates a first embodiment of the light bulb in both the assembled and disassembled configurations; FIG. 2 is a part-sectional side view of the light bulb of FIG. 1; FIG. 3 illustrates a second embodiment of the light bulb; and FIGS. 4 to 7 illustrate the arrangement and operation of the light bulb of the second embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The light bulbs of the present invention, to be hereinafter described, will preferably have power outputs of at least 100 watts, more preferably in the range of 130 to 300 watts when connected to a 220-250 volt 208049_1.DOC 4 O electricity supply; and will have an operating life of, eg., 10,000 hours.

Referring to the first embodiment of FIGS. 1 and 2, the light bulb 10 has a base 20 and a detachable head 40, to be hereinafter described in more detail.

In the embodiment illustrated in FIGS. 1 and 2, the base 20 has an Edison-Screw spigot engageable in a complementary 220-250 V socket, not shown.

1 The base 20 has a metal body portion 22 which is provided with a plurality of spaced heat dissipation holes 23 in the "frusto-conical" shoulder of the metal body portion 22.

A heat sink 24 is provided within, and fixed to, the metal body portion 20 to enable heat generated in the triodes 25 (which control the operation of the light bulb 20), the triodes being mounted on a support plate 26 fixed to the heat sink 24.

A plastics body portion 27 closes the base 20 at the end opposite to the spigot 21 and is provided with a plurality of spring-loaded electrical contacts 28. The plastics body portion 27 has a peripheral rim 29 and latching members 30 (with inwardly-directed fingers operable to releasably engage the head 40 in a bayonet-type connection to be hereinafter described).

The head 40 has a body member 41 of plastics material in which is mounted a plurality of lighting elements 42 of the type having glass (or other transparent material) tubes internally coated with phosphor material(s) excitable by the flow of electricity therethrough.

140419_.DOC The end of the body element 41 spaced from the lighting ;elements 42 forms a substantially circular projection 43 which incorporates latching members 44 complementary with the latching members 30 on the base 20 and electrical contacts 45 engageable with the electrical contacts 28 on the base 20 when the head 40 is operably engaged with the base 20 as shown in FIG. 2.

Heat insulating material 46 is preferably provided within the N interior of the body member 41 of the head 40 to minimise the transfer of heat from the lighting elements 42 towards the base By forming the body member 41 of the head 40 and the body portion 27 of the base 20 of (heat insulating) plastics material, the transfer of heat from the lighting elements 42 to the base 20 is minimised.

Furthermore, the connection of the heat sink 24 to the metal body portion 22 of the base 20; and the provision of the heat dissipation holes 23 in the metal body portion 22; enables sufficient heat to escape from the base 20 to prevent overheating of the diodes 25 (and other electronic components within the base It will be readily apparent to the skilled addressee that the arrangement of the lighting elements 42 on a particular head 40 may be varied to suit the particular intended application. The light bulb 20 of the first embodiment illustrated in FIGS. 1 and 2 is preferably designed for use within a (substantially tubular) reflector to provide a "spotlight" effect.

As the base 20 is the more valuable portion of the light bulb it may be used with a number of replacement heads 40 before the light bulb 140419_1.DOC is replaced.

Alternatively, different heads 40 may be fitted to the base 20 to suit different intended lighting applications.

FIGS. 3 to 7 illustrate a second embodiment of the light bulb which is intended for area illumination, eg., in a particular area of an office/ warehouse/factory or the like. Normally, a plurality of the light bulbs would be arranged in a regular array to ensure even illumination within the building structure in which they are provided.

The light bulbs 110 of the second embodiment of FIGS. 3 to 7 have a base and detachable head 140, with lighting elements 142, arranged to lie on an axis parallel to the longitudinal axis of the reflector 160; where the lighting elements 142 are arranged in a substantially semi-circle to direct the maximum quantity of light to the mouth of the reflector 160.

The head 140 has a raised portion, equivalent to the circular projection 43 of the head 40, which is slidably received in a channel-like latching assembly in a plastic body portion of the base. (In this embodiment, the head 140 is linearly slid into engagement with the base rather than via the bayonet-type connection between the base 20 and head 40 of the light bulb Once again, alternative heads 140 may be fitted to the light bulb 110 to suit different intended applications or to simply replace lighting elements 142 when they have failed.

With both embodiments of the invention, the provision of the base and detachable head; and the insulating barrier created by the plastics 140419_1.DOC of the plastics body portion of the base and the body element of the head minimise heat transfer from the lighting elements to the base; while allowing effective dissipation of the heat generated in the base by the triodes and/or other electronic components; and the provision of the detachable heads enables one base to be used to create a wide range of lighting effects and/ or operate for a longer period than the effective life of the lighting elements per se.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.

140419_1.DOC

Claims (4)

1. A light bulb of the type having a plurality of lighting elements, 00 each lighting element comprising at least one phosphor within a transparent (N tube, the light bulb including: a base, releasably mountable in an electrical socket connectable to an electricity supply; and a detachable head, having a plurality of the lighting elements, Sthe head having first latch means releasably engageable in complementary second latch means on the base and first electrical contacts engageable with complementary second electrical contacts on the base, wherein: the first and second latching means are arranged to provide a bayonet-type connection therebetween, with the first and second electrical contacts being in electrical engagement when the head is operably connected to the base.

2. A light bulb as claimed in Claim 1 wherein: the base has a metal body portion with an Edison-Screw or Bayonet-Cap spigot at one end releasably engageable in an electrical socket; and at the opposite end, a plastics body portion having the second latch means at an opposite end; and the head has a body member of plastics material having the lighting elements at one end and the first latch means and first electrical contacts at the other end.

3. A light bulb as claimed in Claim 2, wherein: 208049_1.DOC 00 the electronics, such as triodes, which control the operation of Sthe light bulb, are mounted on at least one heat sink mounted in, and 00 connected to, the metal body portion of the base; and at least one heat dissipation hole is provided in the metal body portion of the base to allow escape of heat from the interior of the base.

04. A light bulb substantially as hereinbefore described, with reference to FIGS. 1 and 2; or FIGS. 3 to 7; of the accompanying drawings. 208049 1.DOC