GB2382934A

GB2382934A - An electrical connector having a coloured background and contrasting coloured terminal indicators.

Info

Publication number: GB2382934A
Application number: GB0129354A
Authority: GB
Inventors: Henry Horton
Original assignee: Get PLC
Current assignee: Get PLC
Priority date: 2001-12-07
Filing date: 2001-12-07
Publication date: 2003-06-11
Anticipated expiration: 2021-12-07
Also published as: GB0129354D0; GB2382934B

Abstract

An electrical wiring accessory (10) comprising:<BR> a front plate (18) having a front face (12) and a rear face (20);<BR> a contact housing (22) mounted on said rear face;<BR> and terminals (24) being present in said contact housing,<BR> wherein each terminal of the contact housing is provided with a terminal designation consisting of a substantially white marking disposed on a substantially grey background. In a second embodiment the terminal designations are located on an upwardly oriented surface.

Description

Safety System For Electrical Wiring Accessories This invention relates to a safety system for electrical wiring accessories and particularly, but not exclusively, to system for wall mounted electrical sockets and switches.

A common form of wall mounted electrical socket, as illustrated in Fig. 1, includes a front plate having apertures in its front face for the pins of one or more electrical plugs and a contact housing mounted on the rear face of the front plate. The contact housing provides a structure for holding an arrangement of electrical contacts for the pins of a plug received in the socket apertures. The contact housing possesses a series of terminals by which electrical wiring connections can be made to the contacts.

In order to allow the socket to be mounted on the wall a wiring box is firstly recessed into the wall and secured.

Typically such wiring boxes are 35mm deep, in the case of sockets, and 25mm deep, in the case of switches. This depth is required to accommodate the contact housing of the socket together with any additional electrical wiring.

To install a socket it is necessary to align the front plate of the socket with the wiring box and connect the electrical wiring which protrudes from the wall and through the wiring box to the terminals of the contact housing. Once the connection is made the front plate of the socket can then be secured to the wall by any suitable fixing means. Clearly an opposite mode of operation is required to remove the socket.

With the current arrangement there is a considerable safety risk on installing and removing such sockets and

switches, aside from the inherent danger from working with mains supply electricity, there is a danger that wiring will be connected incorrectly to the wrong terminals which could result in serious damage if the socket or switch is allowed to be used in such a condition. As there has been a significant increase in the number of people undertaking D-I-Y (Do-ItYourself) the above-mentioned risk of incorrect electrical connections is increased.

The above-mentioned dangers are heightened since the operation of making these electrical connections usually necessitate working in poor ambient light conditions which result from the contact housing being at least partially immersed into the cavity defined by the wiring box when the connections are being worked on. Sockets in particular are typically installed into a lower portion of a wall which means that any person installing or removing same is positioned above and looks over the socket thus reducing the passage or any ambient light from above yet further.

It is an object of the present invention to provide sockets and switches which are safer to install and remove.

In a first aspect of the present invention there is provided a safety system for an electrical wiring accessory comprising a front plate having a front face and a rear face, a contact housing mounted on said rear face and terminals being present in said contact housing characterised in that each terminal of the contact housing is provided with a terminal designation consisting of a substantially white marking disposed on a substantially grey background.

In a second aspect of the present invention there is provided a method for improving safety during installation and removal of an electrical wiring accessory comprising the steps

of introducing the electrical wiring accessory into a wiring box, wherein a contact housing possessing terminals mounted on a rear face of said electrical wiring accessory is introduced into a cavity defined by the wiring box, and electrical wiring is connected to the terminals thus making electrical contacts characterised in that each terminal of the contact housing is provided with a terminal designation consisting of a substantially white marking disposed on a substantially grey background.

The present invention solves the problem with known electrical wiring accessories by providing an accessory which has terminal designations that are easy to view by a person installing or removing a socket in low ambient light conditions. Anyone using an electrical wiring accessory of the present invention will no longer be mistaken as to which terminal houses which electrical connection. The inventor has surprisingly found that the combination of substantially white terminal designations disposed on a substantially grey background results in exceptional clarity of contrast when viewing the designation, particularly when low ambient light levels are present.

Preferably the whole of the contact housing is substantially grey. The preferred grey of the present invention is any shade of grey within the following range of shades from the darkest shade consisting of the component colours Black 37.5%, Blue 12.5% and White 50% to the lightest shade consisting of the component colours Black 3.9%, Blue 2.3% and White 93.8%. The most preferred range of shades have the darkest shade consisting of the component colours Black 18.8%, Blue 6.2% and White 75% to the lightest shade consisting of the component colours Black 7.8%, Blue 4.7% and

White 87.5%. The most preferred shade of grey for the present invention is RAL 7046-Telegrey 2.

Ideally each substantially white terminal designation is provided on a terminal, however, it is alternatively possible for each designation to appear adjacent to a terminal.

In addition to the terminal designations consisting of substantially white markings, further markings may be provided on the terminals which are colour coded to the colour of the electrical wire which they are intended to be connected to.

For example, fixed electrical wiring in the United Kingdom possess the colour coding of red for the live wire, black for the neutral wire, green and yellow for the earth wire. In this instance the corresponding terminals of the contact housing would possess identical colour markings disposed on the grey background.

In a third aspect of the present invention there is provided a safety system for an electrical wiring accessory comprising a front plate having a front face and a rear face, a contact housing mounted on said rear face and terminals being present in said contact housing characterised in that each terminal of the contact housing is provided with a terminal designation which is disposed on an upwardly oriented surface of the contact housing.

This is advantageous as the terminal designations are disposed so that as a person views the electrical wiring accessory from above, as is customary when installing and removing same, the designations can be viewed immediately thus decreasing the possibility for the person to incorrectly connect the accessory to the electrical wiring.

In a preferred embodiment of this aspect of the present invention the terminal designations are disposed on an upper surface of the contact housing. The disposal of the terminal designations on the upper surface of the contact housing improves the view of any person installing or removing the accessory to further increase the safety with which they can perform the operation. Ideally each terminal is provided in a wedged shaped protrusion extending away from the contact housing and the terminal designation can be provided on the upper surface of this protrusion. Each terminal is provided with locating screws to form and secure electrical connections and the protrusion can be formed to allow the locating screws to be viewed and accessed by a person looking at the upper surface of the contact housing.

It can be envisaged that electrical wiring accessories possessing a combination of at least two of the features of a substantially grey contact housing; substantially white terminal designations; colour coded terminal designations; and upwardly facing terminal designations could provide accessories which are safer to install and remove than known accessories. Other aspects of the invention include any of the above possible combinations.

Embodiments of the invention are described below, by way of example, with reference to the accompanying drawings in which: Fig. 1, illustrates a perspective view of a known wall mounted electrical socket;

Fig. 2, illustrates a perspective view of a wall mounted socket in accordance with an embodiment of the present invention ; and Fig. 3, illustrates a plan view of a wall mounted socket in accordance with an embodiment of the present invention.

In Fig. 1 a known socket is illustrated and it can be seen that it consists of a plate 10 having a rear face 12 to which a contact housing 14 is mounted. The front face of the front plate has three apertures (not shown) arranged to receive the live, neutral and earth pins of a standard UK 240v plug (British Standard BS1363) and two further apertures (not shown) towards the side edges of the plate for the passage of screws (not shown) used to mount the socket on a standard 25mm wiring box.

The contact housing 14 holds an arrangement of contacts (not shown) adapted to engage the pins of a plug received in the apertures in the front face of the plate 10 in a conventional manner. The housing also supports corresponding terminals 16, electrically connected to respective ones of the neutral, earth and live contacts, for connection to e. g. the wiring of a ring main in a building.

A pair of rocker switches (not shown) project through the front face of the plate 10 and can be used to isolate respective live contacts of the contact housing from the corresponding terminals.

In the known socket shown in fig. 1 the terminals 16 are recessed into the contact housing 14 and are located toward the lower extremity of the housing 16 away from a person installing or removing the socket. Once this socket is immersed into the cavity in the wall defined by the wiring box

(not shown) the ambient light levels will be minimised and the person working on the socket will be presented with the difficult task of mentally assigning the correct terminal designations to each terminal.

An embodiment of the present invention is illustrated by way of the socket as shown in fig. 2. In this embodiment it can be seen that the socket consists of a plate 18 having a rear face 20 to which a contact housing 22 is mounted. As with the known socket, the contact housing 22 holds an arrangement of contacts (not shown) adapted to engage the pins of a plug (not shown) received in the apertures in the front face (not shown) of the plate 18 in a conventional manner. The contact housing 18 is uniformly provided in the shade of grey corresponding to RAL 7046.

The contact housing 22 possesses a series of terminals 24 which correspond to the neutral, earth and live electrical wires to which a series of electrical connections are to be made. In order to increase the safety with which these electrical connections are made each terminal is provided with a terminal designation (not shown) which is provided by a substantially white marking on or adjacent to the corresponding terminal.

The terminals 24 are located on an upper extremity of the housing 22 and are orientated such that the terminals 24 can by viewed easily and directly by a person looking down on to the socket. Fig. 3 shows that each terminal 24 is provided in the form of a wedged shaped protrusion which extends away from the main body of the contact housing 22. The protrusion is orientated such that locating screws 26, which are used to form and secure the electrical connections, are accessible

from the top of the socket and are in the line of sight of a person looking down on to the socket.

The particular contrast created between the RAL 7046 grey housing 22 and the substantially white markings of the terminal designations is particularly distinct resulting in the recognition of each terminal 24 being readily apparent, even in low ambient light conditions.

Although not shown in fig. 2 or fig. 3, the substantially white markings of the terminal designations are accompanied by a colour coded marking which corresponds to the colour of the wiring it is intended to be connected to, i. e. for fixed electrical wiring in the United Kingdom possess the colour coding of red for the live wire, black for the neutral wire, green and yellow for the earth wire.

As will be apparent to the skilled person, numerous modifications and variations can be made to the embodiments specifically described above without departing from the invention. For instance, although the use of an accessory has been illustrated and described in the context of switches and sockets which are viewed by a person from above, if a particular socket or switch is to be installed or removed so that the person performing that task would be beneath and looking up at same, then the contact housing 22 could be orientated so that the terminals are reversed, i. e. present on a lower extremity with the protrusions and markings thereon facing downwards, to increase the safety of such a task.

Claims

CLAIMS: 1. An electrical wiring accessory comprising: a front plate having a front face and a rear face; a contact housing mounted on said rear face; and terminals being present in said contact housing, wherein each terminal of the contact housing is provided with a terminal designation consisting of a substantially white marking disposed on a substantially grey background.
2. A method for installation of an electrical wiring accessory comprising the steps of: introducing the electrical wiring accessory into a wiring box; wherein a contact housing possessing terminals mounted on a rear face of said electrical wiring accessory is introduced into a cavity defined by the wiring box ; and electrical wiring is connected to the terminals thus making electrical contacts, wherein each terminal of the contact housing is provided with a terminal designation consisting of a substantially white marking disposed on a substantially grey background.
3. The electrical wiring accessory of claims 1-2, wherein the whole of the contact housing is substantially grey.
4. The electrical wiring accessory of claim 3, wherein the grey of the contact housing is any shade of grey within the following range of shades from the darkest shade consisting of the component colours Black 37.5%, Blue

12.5% and White 50% to the lightest shade consisting of the component colours Black 3.9%, Blue 2.3% and White

93.8%.
5. The electrical wiring accessory of claim 3, wherein the grey of the contact housing is any shade of grey within the following range of shades from the darkest shade consisting of the component colours Black 18.8%, Blue

6.2% and White 75% to the lightest shade consisting of the component colours Black 7.8%, Blue 4.7% and White

87.5%.

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6. The electrical wiring accessory of claim 3, wherein the grey of the contact housing is RAL 7046-Telegrey 2.
7. The electrical wiring accessory of claims 1-6, wherein each substantially white terminal designation is provided on a terminal.
8. The electrical wiring accessory of claims 1-6, wherein each substantially white terminal designation is provided adjacent to a terminal.
9. The electrical wiring accessory of claims 1-8, wherein the terminal designations comprise further markings provided on the terminals which are colour coded to the colour of the electrical wire which they are intended to be connected to.
10. An electrical wiring accessory comprising: a front plate having a front face and a rear face; a contact housing mounted on said rear face and terminals being present in said contact housing' wherein each terminal of the contact housing is provided with a terminal designation which is disposed on an upwardly oriented surface of the contact housing.
11. The electrical wiring accessory of claim 10, wherein the terminal designations are disposed so that as a person views the electrical wiring accessory from above the designations can be viewed immediately.
12. The electrical wiring accessory of claims 10-11, wherein the terminal designations are disposed on an upper surface of the contact housing.
13. The electrical wiring accessory of claims 10-12, wherein each terminal is provided in a wedged shaped protrusion extending away from the contact housing, the terminal designation being provided on the upper surface of this protrusion.
14. The electrical wiring accessory of claim 13, wherein each terminal is provided with locating screws to form and secure electrical connections and the protrusion are formed to allow the locating screws to be viewed and accessed by a person looking at the upper surface of the contact housing.

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15. An electrical wiring accessory according to claims 1,3-9 and claims 10-14.
16. An electrical wiring accessory according to claims 2-9 and claims 10-14.
17. An electrical wiring accessory substantially as hereinbefore described with reference to, and as illustrated in, Figures 2 and 3 of the accompanying drawings.
18. A method for installation of an electrical wiring accessory substantially as hereinbefore described with reference to, and as illustrated in, Figures 2 and 3 of the accompanying drawings.