GB2461846A

GB2461846A - Lights suitable for use in potentially hazardous areas

Info

Publication number: GB2461846A
Application number: GB0812608A
Authority: GB
Inventors: Hector Finch
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-07-10
Filing date: 2008-07-10
Publication date: 2010-01-20
Also published as: GB0812608D0

Abstract

A lights suitable for use in potentially hazardous areas such as kitchens, bathrooms and outdoors, where the ingress of dust or water vapour could is undesirable, comprises a protective lamp unit that is fitted onto a light fitting as a component but integral part of that light fitting. The invention employs a device that protects the lamp and the lampholder against the ingress of water, water vapour and dust. This device is a light fitting comprising a lamp holder mount 6, a lampholder 5, a lamp 7 and shade 1 that fit tightly together by way of the shade ring 4 and lens mount ring 2 to form a single unit.

Description

LIGHTS SUITABLE FOR USE IN POTENTIALLY HAZARDOUS AREAS

This invention provides a solution for allowing more choice for lighting in kitchens, bathrooms and outdoors, where the ingress of dust or water vapour could otherwise stop them working or compromise electrical safety.

It is a protective lamp unit that is fitted on to a light fitting as a component but integral part of that light fitting.

1. Background to the invention

Most lights are unsuitable for use outdoors or in potentially hazardous areas indoors like bathrooms and kitchens. They lack the degree of ingress protection that would prevent water vapour or dust entering the light, which could stop them working or compromise their electrical safety.

As a result, the range of lights that you can specify for these locations is limited. For example, a standard wall light with a lampholder that is not entirely enclosed is not suitable for use by a sink, as the electrical components can be exposed to splashes of water. In a situation that the water makes contact with the lampholder or other electrical components, the water becomes a conductor of electricity and the light fitting becomes live' and potentially fatal if touched.,._ There are limited solutions for lights designed specifically for use in bathrooms, outdoors or near the kitchen sink: a. The lights are designed as a sealed unit so that the lamp and electrical connections are entirely enclosed and they run on a regular mains electricity supply of 220 volts.

These can be wall or ceiling mounted fittings.

b. For ceilings, halogen spot-lights that run on a low voltage electricity supply are an alternative solution as the current in use is very low and therefore does not present a safety hazard in the presence of water vapour.

However, to deliver the lower voltage supply they require a remote transformer to be fitted in the wall or ceiling cavity, which adds to the bulk and cost of filling them.

2. Prior art

There have been numerous attempts to invent lights suitable for use outdoors or in potentially hazardous situations as outlined above, A preliminary search has revealed inventions designed to minimise ingress by: o improving the way that a light's casing fits over the lampholder (publication number JP200331 7526) o improving the way that a light's casing attaches to the wall (application number G819870020217) o fitting a collar between the light's lampholder and shade (publication number US6799869) o securing a cap over the light bulb and filling a sealing plug around the cable (publication number FR283881 1).

But each of these inventions proposes a design for a specific light and addresses the problem of minimising ingress for that individual light. We are not aware of another invention that provides a generic method for making all kinds of hard wired lights suitable for use in potentially hazardous locations.

3. Aim The object of this invention is to provide a generic solution to ingress protection, so that virtually any hard-wired light fitting can be used in a potentially hazardous location for example where water vapour or dust might be present.

To enable this generic solution the invention will: o convert a conventional light for use in these conditions simplify the design of new lights for use in these conditions 4. The Protective Light Unit The solution employs a device that protects the lamp and the lampholder against the ingress of water, water vapour and dust. This device is a light fitting (see Figure 1) that comprises a lampholder mount (6), a lampholder (5), a lamp (7) and shade (1) that fit tightly together by way of the shade ring (4) and lense mount ring (2) to form a single unit. The electrical cable or flex (9) enters the base casing (3) by way of a piece of threaded tube (8).

For convenience, we refer'to this device as the Protective Light Unit (PLU).

The PLU functions as a component that is designed to meet the regulatory requirements which apply to the use of lights in locations where ingress of water, water vapour or dust might otherwise compromise electrical safety.

It replaces the lampholder of a light fitting so that the light gains a greater level of ingress protection, subject to approval by the appropriate regulatory and licensing authorities, which may be obtained on a class basis for a specific design of light fitting (see Figure 4).

4. Description

We have established that this invention provides a generic method of making lights suitable for use in potentially hazardous locations, for example where water, water vapour or dust might be present.

We have established that the method relies on replacing the conventional lampholder in a light fitting with an integral unit known as the Protective Light Unit (see Item 3 above) Fitting the PLU inside a host light is straightforward. The PLU screws onto the threaded tube that is present in most conventional light fitting designs (see Figure 4).

The fitting method is similar for a wide range of light fittings, which adds to the generic nature of this invention. For the purposes of illustration, we show a 10mm tube, commonly used in light fittings. The PLU, however, can be made to fit a tube of any size.

The PLU itself is not much bigger than a standard candle lamp of the type you find in a great many lights. This means that it fits inside a wide variety of designs of light fittings.

To change the lamp, the shade can be easily unscrewed and a new lamp fitted into the 2 pin lampholder.

4.1 Generic solution The PLU can be fitted into most light fittings as follows: hanging lights, pendant lights, wall lights, table lights, floor lights, desk lights, outside lights, patio lights, flush fitting lights and chandeliers.

5. Diagrams We describe the invention further in the following paragraphs by way of example with reference to the accompanying diagrams: Figure 1 shows the components of one embodiment of the PLU. The image to the left of the page (Figure 1.1) shows the individual components. The image to the right of the page shows how they fit together and the hidden detail (Figure 1.2).

Figure 2 shows another embodiment of the PLU. In this case the lamp is shown with a candle shape shade, one of a wide variety of embodiments that the PLU can take.

Figure 3 shows in detail the housing of the device, which provides protection against the ingress of dust and water vapour.

Figure 4 shows how the device is incorporated into a host light fitting, to provide ingress protection.

Figure 5 shows a variety of lights fitted with a PLU instead of a conventional lampholder. For example, Figure 5.1 shows a chandelier fitted with seven PLUs, one on each branch of the chandelier in place of a conventional lampholder. Figure 5.2 shows a wall light fitted with two PLUs. Figure 5.3 shows a table lamp fitted with a single PLU; and Figure 5.4 shows a pendant, a hanging light fitted with a single PLU.

5.1 Detailed description

Figure 1 As illustrated in Fig 1, the device comprises: a shade 1, with an integral mounting ring 2, which screws onto the threaded lampholder mount 6; a a shade ring 4, which screws onto the lampholder mount; this is designed to secure a conventional lamp shade in place if desired (not shown); a a lamp 7 and lampholder 5 (we show a 40W halogen G9 lamp and matching lampholder for the purposes of illustration); o the lampholder sits inside a lampholder mount 6, which threads into a base casing 3; o an electrical flex 9 enters the lamp through a tight-fitting hole in the bottom of the base casing; this flex carries the electricity supply to the lampholder.

Figure 2 As shown in Fig 2, the PLU can take a wide variety of embodiments; in this case the lamp is shown with a candle-shape shade. Other shade shapes are possible.

Figure 3 Fig 3 shows the PLU without its lampholder, lamp and lampholder mount. This is in order to highlight the protective housing of the device, which comprises a shade I with an integral mounting ring 2 and a base casing 3. An optional shade ring 4 secures a conventional lampshade in place if desired.

The components of the housing fit tightly together to form the PLU, The connection between electricity supply and lampholder occurs within this housing, which provides protection against the ingress of dust or water vapour, which otherwise could compromise electrical safety.

Figure 4 Fig 4 shows the main steps involved in fitting a wall light (for the sake of this illustration) with a PLU in place of a conventional lampholder to provide ingress protection. These steps are: o the conventional lampholder is unscrewed from filling and removed together with its electrical flex (Figure 4.1) o the wiring for the PLU is introduced through the arm of the light fitting and played through the tube at the top of the arm (Figure 4.2) o the PLU is attached in place of the conventional lampholder; the PLU base casing screws onto the threaded tube, which is present in most conventional light fittings (Figure 4.3). We show a 10mm tube, commonly used in conventional light fittings, for the purposes of illustration, o the PLU is fitted with (in this case) a 09 halogen lamp.

o the PLU shade is screwed onto the lampholder mount o a shade ring is fitted onto the lampholder mount to allow use of a conventional lamp-shade, if desired.

In this figure, we show a wall light as the host for the PLU for the purposes of illustration.

The method of installation is similar for a wide range of host lights, for example hanging lights, pendant lights, table lights, floor lights, desk lights, outside lights, patio lights, flush fitting lights and chandeliers.

Figure 5 Figure 5 shows a variety of lights fitted with a PLU instead of a conventional lampholder. In use, the PLU replaces a conventional lampholder and provides protection against the ingress of dust or water vapour, which otherwise could compromise electrical safety.

o Figure 5.1 shows a chandelier fitted with a PLU in place of a conventional lampholder on each branch of the chandelier o Figure 5.2 shows a wall mounted light ° Figure 5.3 shows a table lamp Figure 5.4 shows a pendant, a hanging light.

Claims

CLAIMSA light fitment comprising: a a cup-shaped base member having a base end arid an open end, the base end comprising an opening for receiving an electrical cable, the cup-shaped member having engagement means on an interior surface of the cup-shaped base member; o a lampholder mount having electrical connections at a first end for connection to an electrical cable and having co-operable engaging means on an exterior surface for engagement with the engaging means of the cup-shaped member, the lampholder mount being sized to extend into and be received by the open end of the base member, and further comprising at a second end bulb mounting means comprising electrical connections for mounting and electrically connecting a lampholder to the lampholder mount; o a lampholder comprising at a first end mounting means for attachment and electrical connection to the bulb mounting means of the lampholder mount and comprising at a second end means for receiving and electrically connecting to a light bulb; and o a light transmissive cover having attaching means for attaching the light transmissive cover to the lampholder mount, such that in use the attaching means of the light transmissive cover abuts the cup shaped base member, wherein in use, the light transmissive cover in combination with the cup shaped base member define an enclosed space which contains the lampholder mount, a lampholder and a bulb mounted in said holder and their electrical connections such that, in use, the enclosed space is protected from the environment outside of the cover and the base member.
2. The light fitment of claim 1 wherein the lampholder mount has a threaded exterior surface and wherein the attaching means of the light transmissive cover comprises a mounting ring, said mounting ring having an interior thread for threaded engagement with the lampholder mount, and an exterior portion for engagement with the light transmissive cover.
3. The light fitment of claim I wherein the lampholder mount has a threaded exterior surface and wherein the attaching means of the light transmissive cover comprises a threaded surface provided on an interior surface of the light transmissive cover for threaded engagement with the lampholder mount.
4. The light fitment of any preceding claim wherein the attaching means ofthe light trarismissive cover further comprises a shade ring for mounting a light shade on said light fitment, wherein the shade ring is adapted to fit onto the lampholder mount between the light transmissive cover and the base.
5. A method of assembling the light fitment in accordance with any preceding claim, said method comprising: o engaging the lampholder mount in the open end of the cup-shaped member; o mounting a lampholder on the lampholder mount; and ° attaching said light transmissive cover to said lampholder mount so as to abut the cup-shaped member and thereby form an enclosed space.
6. The method of claim 5 further comprising the steps of: passing a free end of an insulated electrical cable though said opening in the base end of the cup-shaped member; and connecting said electrical cable to said lampholder mount.
7. A method for fitting a light fitment according to any one of claims 1 to 4 to a lighting unit comprising an existing light fitment and an existing electrical cable which electrically connects a power supply to the existing light fitment, said method compnsing: Hector Finch July 2008 ° disconnecting the existing electrical cable from the power supply; o removing the existing light fitment from the lighting unit; o removing the existing electrical cable from the lighting unit; o assembling the light fitment according to 6 so as to form an enclosed space protected from the environment; a passing a free end of the insulated electrical cable through the lighting unit; o fitting said base member to said lighting unit; and o electrically connecting the free end of the insulated electrical cable to the power supply.
8. A light fitment substantially as hereinbefore described with reference to figures 1 to 6.
9. A method for assembling a light fitment as hereinbefore described with reference to figures 1 to6.