AN IMPROVED LIGHT TUBE ASSEMBLY

FIELD OF THE INVENTION

This invention relates to electrical components. More particularly, although

not exclusively, it discloses an improved fluorescent light tube assembly for

light boxes and signs.

BACKGROUND TO THE INVENTION

With existing fluorescent lamps the tubes are typically mounted between lamp

holders on a light fitting support rail which also carries the ballast, capacitor

and starter components for the tube. There is however no provision in these

lamp assemblies for interconnecting banks of fluorescent tubes as required for

example in illuminated signs or ceiling installations. Consequently each lamp

assembly currently has to be separately connected to the mains supply using

individual plugs and power points which are hard-wired into the sign support

frame or ceiling. Such installations are therefore time consuming and

expensive.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to ameliorate the aforementioned

disadvantage and accordingly a lamp assembly of a type for fitting as

multiples in an illuminated sign, ceiling or other installation is disclosed; said

lamp assembly including a connection means for receiving cable plugs to

interconnect said assembly with a power supply either directly or via another

like assembly in said installation.

Preferably said lamp assembly comprises a fluorescent tube.

It is further preferred that said lamp assembly includes all necessary

components for operating said tube such as ballast, starter and capacitor.

It is farther preferred that said connection means comprises male and female

plug bases for respective incoming and outgoing power cables.

It is further preferred that said plug bases are located one adjacent the other on

a support rail of the lamp assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The currently preferred embodiment of the invention will now be described

with reference to the attached drawings in which:

figure 1 is a schematic perspective view of a fluorescent lamp

according to said invention,

flgure 2 is a side elevation view of the lamp assembly of figure I ₅

figure 3 is a top elevation view of the lamp assembly of figure 1 with

the fluorescent tube omitted,

figure 4 is a detailed perspective view of the plug bases for the lamp

assembly of figure 1,

figure 5 is a schematic circuit diagram showing three interconnected

lamp assemblies according to the invention, and

figure 6 is a schematic perspective view of a fluorescent lamp

assembly according to a second embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to figures 1 to 3 there is a fluorescent light assembly which

comprises a folded metal support rail 1 with lamp holders 2 at each end and a

fluorescent tube 3 extending the length of the rail between said holders. Also

mounted along the rail are a starter 4, ballast 5 and capacitor 6 of conventional

design. The complete wiring circuit for the aforementioned lamp holders,

starter, ballast and capacitor is not shown in detail as it would be familiar to a

person skilled in the ait.

As best shown in figures 2 and 3 spaced apart fixing brackets 7 of any suitable

design may also be fitted to the back of the rail.

The support rail 1 is preferably of reduced width (with this embodiment about

20 mm) to minimise the appearance of shadows or dark areas in sign

illumination as occurs with the wider support rails of prior art lamps.

In accordance with this invention the rail 1 is also fitted with a pair of

connectors 8, 9 as best shown in figures 2 and 4. These are preferably

mounted on a flange 10 which extends up from the side lip 3 1 of the support

rail. Preferably, as shown in figure 5 the upper connector 8 is in the form of a

male three pin plug base which engages a female power-in plug 12 and the

lower connector 9 is in the form of a three pin female plug base which

engages a male power-out plug 13.

During installation of multiple lamp assemblies such as for example in

illuminated signs the light tubes can be quickly and easily connected to mains

power by plug in cables extending between the respective power-out

connectors 9 and the power-in connectors 8 of said assemblies. As shown in

figure 5 the upper lamp assembly is connected directly to mains supply via its

male power-in plug 12. The additional two assemblies are then connected in

tandem using power cables 14 with male/female plugs 16, 17 extending

between the aforementioned power-in and power-out plug bases 8, 9. While

only three lamp assemblies are shown in figure 5 the invention extends to any

number in accordance with installation requirements.

With the second embodiment of the invention shown in figure 6 the main

components which correspond in function to those of figures 1 to 5 are

identified by the same numbers which however are primed ( ^ς ) to distinguish

them.

With this embodiment the mounting fittings at each end for the lamp holders

V are of similar form. They comprise metal straps 18 extending across the

width of the support rail 3 ' and spot welded in place. The straps are folded

upward from the rail into a square U shaped configuration as shown in figure

6 to form planar side and top faces with rectangular apertures 19 to receive the

lamp holders 2'. This allows said lamp holders and the fluorescent tube V to

be fitted either directly in front of the rail 1 ' or to one side. Mounting the tube

to one side as shown reduces the clearance space and thus the required

thickness for illuminated sign boxes.

The power-in and power-out connectors 8' and 9' are mounted to an L shaped

flange 10' and face along the rail 1 ' in the direction of one of the lamp holders

2'. The flange 10' with this embodiment is also spot welded in place across

the width of the rail 1 '. Multiple lamp assemblies according to this second

embodiment (as used for example in sign illumination) can be connected in

tandem in a similar manner to that of the first embodiment shown in figure 5

It will thus be appreciated that this invention at least in the form of the

embodiments disclosed provides novel and improved forms of lamp

assemblies to enable multiple installations without separate hard-wired power

points and plugs. It is envisaged by the inventor that lamp assemblies

according to this invention may reduce installation times and costs by up to

80%. Clearly however the examples described are only the currently preferred

forms of the invention and a wide variety of modifications may be made

which would be apparent to a person skilled in the art. For example the design,

type and placement of the power-in and power-out connectors may be

modified following further development work by the inventors. Also, while

the preferred embodiments relate to a specific design of fluorescent lamp

assembly as used in signage the invention extends to other types of light

assemblies as may be used for example in ceiling installations.