GB2433356A

GB2433356A - Two pin power socket with fuse or switch

Info

Publication number: GB2433356A
Application number: GB0525630A
Authority: GB
Inventors: David Banes
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-12-16
Filing date: 2005-12-16
Publication date: 2007-06-20
Also published as: GB0525630D0

Abstract

A two-pin mains power socket comprises an automatic circuit breaking means (eg a fuse) and/or an on/off switch. The socket, with power contacts 1, 2, and optional earth contacts 3, may have a built-in fuse 5 in a socket 8 for each socket. Alternatively, or in addition, it may have an on/off switch 4 for each socket.

Description

P1u socket This invention relates to mains (domestic) power sockets. In

particular, it relates to a two-pin mains power plug socket that is provided with an automatic circuit breaking means andlor an onloff switch.

Domestic AC power plugs and sockets are well known, they allow a connection between mains electricity (usually single-phase, AC electrical power) and appliances commonly used in homes, offices.

Power plugs comprise male contacts (prongs), usually brass and often tin or nickel plated, that interface mechanically and electrically to the mains. Such plugs have at least a live contact and a neutral contact. A power plug socket provides a connection point that delivers mains electricity to a plug that is inserted into it. A socket is the opposite of a plug, and has only female contacts. a.. *

Electrical plugs and their sockets differ by country in shape, size and features. ** *

In the United Kingdom plugs are governed by British Standard (BS) 1363. Thi plug, has three rectangular prongs (live, neutral and earth) that form a triangle. The livr. **S*

and neutral prongs are 4 x 6 x 18 mm with 9 mm of insulation (the insulation being * : :: provided to prevent a user touching any live part of the prongs whilst unplugging an appliance), and spaced 22 mm apart. The earth prong is 4 x 8 x 23 mm.

BS 1363 plugs are fused so as to protect a flex linking the plug and an applicance.

The earth pin is operable to open shutters that may be provided on the socket to cover the live and neutral female contacts. The majority of UK plug sockets further comprise a switch that is provided to shut off the power supply to the live female contacts of the plug socket. UK plug sockets are generally fixed to walls using screws. It is regarded as one of the safest systems in the world.

The majority of European countries use the CEE 7/16 standard plug (Europlug).

This is an unearthed two-wire plug that features two round 4mm pins. It will mate with any socket that accepts 4.0mm round contacts spaced 19mm apart.

A variant also commonly found in European countries is the CEE 7/4 standard plug ("Schuko plug"), which is similar to the Europlug except that it features two grounding clips on the side of the plug. It has two 4.8mm round contacts spaced 19mm apart.

Unlike BS 1363 plug sockets, the CEE 7/16 and CEE 7/4 sockets do not feature switches and are not fixed to walls using screws. The European plugs are not as safe as BS 1363 plugs.

The present invention arose in a bid to improve the safety of European style 2-pin plugs by the provision of an improved plug socket compatible with CEE 7/16 or CEE 7/4 standardplugs. U... *

In some European countries (outside the UK) and elsewhere, mains circuits are U...'.

separated according to the type of device or appliance to be connected. For example a * heavy-duty (higher current) circuit may be specifically intended for large demand kitchen appliances such as washing machines or cookers and a separate lower current circuit m:::, be provided for lamps, charging devices and so on. The individual circuits might be * * protected by a (central) fuse or circuit breaker. Problems could then arise if a large current requiring' device is inadvertently plugged into a lower demand' circuit. The mains circuit itself may be damaged and a fire or electrical shock risk.

The present invention also seeks to provide an improved circuit configuration which might provide greater safety.

According to a first aspect of the present invention there is provided a two-pin mains power plug socket comprising an automatic circuit breaking means.

The circuit breaking means is preferably a fuse, rated at a chosen ampage, but may alternatively be a solid state circuit breaker or other circuit breaker means. If an appliance requiring more current than the circuit then the circuit to which the socket is attached, is plugged in to a socket according to the invention, then the fuse, or other load-limiting device will blow safely.

According to a second aspect of the present invention there is provided a two-pin mains power plug socket comprising an on/off switch.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a wiring diagram showing a first embodiment of the invention; Figure 2 is a wiring diagram showing a second embodiment of the invention; Figure 3 is a front view of a single socket according to the invention; and Figure 4 is a front view of a double socket according to the invention. * 11$ * * Referring to Figure 1, there is shown a wiring diagram that represents a first embodiment of the invention. The socket represents a development of a CEE 7/4 socket There is provided a live female contact 1 and a neutral female contact 2, for receiving tI ** live and neutral pins of a CEE 7/16 or CEE 7/4 plug, and two grounding clips 3. The *...* * S. * socket is connected to the mains power supply through a live wire connector 6 and a neutra& a* wire connector 7. Between the live wire connector 6 and the live female contact I there is provided an on/off switch 4 and a fuse 5 that are connected in series.

Referring to Figure 2, there is shown a wiring diagram that represents a second embodiment of the present invention. The socket illustrated is a double socket that features female contacts 1, 2 for two plugs. Whilst the socket is shown without grounding clips, it should be noted that a double socket according to the invention may be provided with clips 3 in the same manner as the first embodiment. In such a case, all of the grounding clips would preferably share a common earth connection. The double socket is provided with one live wire connector 6 and one neutral wire connector 7. Between the live wire connector 6 and the live female connectors I a pair of on/off switches 4 and a pair of fuses are provided. The switches 4 and the fuses 5 are connected in parallel, so that between the live wire connector 6 and each live female connector there is provided a switch 4 and a fuse 5 connected in series.

Referring to Figure 3 there is shown a front view of a single plug socket according to the invention. The plug socket features a base plate 10 that may be fixed directly to a wall, via screws 9, with elements of the socket fixed to a rear face of the base plate and received by a void in the wall. A fuse socket 8 is mounted on the plate 10 to allow a user to access the fuse 5 without removing the plate 10 from the wall.

Referring to Figure 4 there is shown a double plug socket according to the invention. The plug socket features a base plate 10 that forms part of a housing ii. The housing 11 may be mounted to a wall using screws (not shown) with the base plate mounted to the housing 11 using screws 12. The double socket depicted features grounjrij I..

clips 3. * *

S.....

The single or double sockets may be embodied in either mounting configuration may or may not feature grounding clips.

S *5*S

The invention may of course be used with triple (or greater) sockets, each beings: *: : protected by a sigle fuse, or all being protected by one fuse. Similarly, one or a plurality of switches may be provided.

Claims

Claims 1. A two-pin mains power plug socket comprising an automatic

circuit breaking means.

2. A socket as claimed in claim 1, wherein the circuit breaking means comprises a fuse.

3. A socket as claimed in claim I or 2, wherein the socket comprises an on/off switch.

4. A socket as claimed in claim 3, wherein the circuit breaking means and switch are arranged in series. * * *

5. A socket as claimed in any preceding claim, comprising two or more sets of femal: contacts, such that two plugs may be attached to the mains power supply. * .

S.....

S

6. A socket as claimed in claim 5 wherein each set of female contacts is associated:*. .. * 5*

with a respective switch. S... * S...

7. A socket as claimed in claim 5 or 6 where each set of female contacts is associai'c: with a respective circuit breaking means.

8. A socket as claimed in any preceding claim that may be attached to a wall using screws.

9. A socket as claimed in any preceding claim, wherein the socket is grounded.

10. A two-pin mains power plug socket comprising an on/off switch.

11. A socket substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.