EP1485972B1

EP1485972B1 - Switched mains socket

Info

Publication number: EP1485972B1
Application number: EP03708347A
Authority: EP
Inventors: Lawrence Murray Lonergan; Carl Lee Dunford
Original assignee: Eaton Electric Ltd
Current assignee: Eaton Electric Ltd
Priority date: 2002-03-15
Filing date: 2003-03-12
Publication date: 2007-08-01
Anticipated expiration: 2023-03-12
Also published as: GB2386480A; EP1485972A1; GB0206205D0; WO2003079501A1; CN1643745A; GB2386480B; ATE368949T1; DE60315269D1; CN1643745B; AU2003212527A1

Abstract

A switched socket outlet comprising a housing containing at least one switch contact mechanism in a predetermined position, and a corresponding actuating mechanism including an operating member [12,14] which is adapted to be mounted in alternative positions relative to the housing. The actuating mechanism may include a reversible rocker arm [24] which carries the operating member [12] at one end, or alternatively, the rocker arm [24] may have a mounting for an operating member [12] at at least two alternative positions so that the operating member [12] can be mounted at either one of the positions. The switched socket outlet may also comprise spring biased safety shutters [34] which co-operates with the mains plug and switch mechanism in such a way that the operating member [12] is locked into the "off" position when the plug is removed from the socket.

Description

This invention relates to socket for mains voltage supply circuits, and particularly to sockets incorporating switches, and having improved safety features.
The invention is especially (although not exclusively) applicable to the construction of "twin sockets", that is to say, outlets which incorporate two circuits in a single unit. These are usually intended to be wall mounted, each of the outlets having a respective control switch which is adapted to connect it to, or isolate it from, the mains supply circuit. Conventionally, such "twin socket outlets" incorporate a pair of rocker style switch members, which are mounted on the front plate just above, and between, the positions of the sockets themselves, as illustrated in Figure 1.
However, the arrangement of the two switches in the adjacent positions can lead to the user accidentally actuating the wrong switch, and thus, (for example) switching off an appliance which was intended to be left switched on.
Accordingly, there has recently been a requirement for socket outlets of the kind illustrated in Figure 2, in which the switches are mounted "outboard" of the sockets, so that a user can easily distinguish them, even when the socket is located in relatively inaccessible position (such as behind a piece of furniture) or when the user is elderly or lacking in manual dexterity.
Unfortunately, however, because of the complexity of the plastic moulding which forms the internal housing for the socket and switch mechanisms, it is expensive for manufacturers to produce such modified mechanisms, so as to enable alternative switch/socket layouts, for example as illustrated in Figure 2, to be easily produced. Accordingly, one aim of the present invention is to provide a switch/socket mechanism which is easily reconfigurable, so that the or each actuating switch can be arranged to the left or right of its respective socket, that is to say, in the case of a twin socket outlet, in either a "inboard" or a "outboard" position.
The document " EP-A-0 125 141 " discloses a switched socket outlet according to the preamble of claim 1.
To this end the present invention provides a switched socket outlet comprising a housing containing at least one switch contact mechanism in a predetermined position, and a corresponding actuating mechanism including an operating member which is adapted to be mounted in alternative locations relative to the housing.
It is a second aim of the present invention to provide a socket outlet with safety shuttering, which is so arranged as to provide an interlock between the shutter and the switch, so that the switch is locked into the "off" position in the absence of the plug. Preferably, the arrangement is such that, when the plug is removed, the switch automatically reverts to the "off" position.
Some embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a twin socket outlet front plate, incorporating "inboard" switches;
Figure 2 is a perspective view of a twin socket outlet front plate, incorporating "outboard" switches;
Figure 3 is a perspective view of a reconfigurable switch mechanism in accordance with a first embodiment of the present invention, showing the switches in a "inboard" position;
Figure 4 shows the same mechanism as Figure 3, but with the switch members arranged in the "outboard" position;
Figure 5 shows the same mechanism as Figures 3 and 4, but with the switch members arranged in "staggered" positions, that is to say, one "inboard" and one "outboard",
Figure 6 shows a perspective view of a switch mechanism in accordance with a second embodiment of the invention, including a switch/shutter interlock mechanism.
Figure 7 is a longitudinal cross-section of a twin socket mechanism, showing the rocker switch and interlock mechanism in a first position; and
Figures 8 to 11 are cross-sections corresponding to the cross-section of Figure 7, showing the mechanism in different successive positions.

Referring firstly to Figure 3, the illustration shows the internal face of a moulding 2 which, in use, will be mounted behind a front plate of the general kind illustrated in Figure 1. The moulding includes formations indicated generally at 4 and 6, which provide shuttered socket outlets, as well as respective mountings 8 and 10, above each of the sockets, for the operating members of rocker switch assemblies referenced generally as 12 and 14 respectively.
As shown in the drawing, the moulding includes recesses 16 and 18 to receive the live and neutral pins of a mains plug, in a conventional side-by-side arrangement, as well as a corresponding recess 20 for the earth pin.
Above the position of each socket is a recess for a switch mechanism of a generally known kind, incorporating metal blades, which is not illustrated in detail, but is adapted to be actuated by a plunger 22 which is mounted on a rocker arm 24.
Each rocker arm carries a pair of spaced apart projections 26 and 28 which are adapted to cooperate with mating recesses on the rear face of the front plate of the socket assembly, and the operating member 14 is mounted on one end of the rocker arm, so that the mechanism can be toggled between the on and off switch positions in the usual way, by pressure on the upper or lower parts of the front face of the member 14. The inboard end of each rocker arm 24 is located in a suitably shaped inboard bracket member 30 (only the one for the lefthand rocker arm 24 being visible in the view of Figure 3) so that in the assembled condition as shown, the rocker arm and the actuating member are accurately located by a combination of the inboard bracket 30 at the inner end of the assembly, and the two projections 26 and 28 along the length of the rocker arm.
A corresponding outboard bracket 32, is also arranged at each of the extreme left and right-hand sides of the housing, and the arrangement is such that during assembly, the rocker arm 24 can either be positioned as shown in Figure 3, with its operating member 14 or 12 closest to the centre of the assembly, or, in effect by rotating it through 180° about the position of the actuating plunger 22, to an alternative "mirror image" position, in which each operating member 12 or 14 is outboard of the plunger 22. Figure 4 illustrates the corresponding arrangement, in which the two rocker arms 24 have been mounted in the housing, so that the operating members 12 and 14 are in the "outboard" positions. It will be appreciated that the rocker projections 26 and 28 are symmetrically arranged relative to the position of the plunger 22, as are their co-operating recesses in the rear surface of the front plate, so that the projections and the recesses will still co-operate in the same way. Again, as illustrated in Figure 5, it is also possible to arrange one rocker arm 24 so that its actuating member 12 is in the "inboard" position, whilst the other rocker arm is arranged so that its operating member 14 is in the "outboard" position.
It will, of course, also be clear from the drawings, that it is possible to construct a single socket outlet, comprising just the left-hand half or the right-hand half of the moulding illustrated in Figures 3 to 5, which similarly allows the switch operating member to be positioned either to the left or to the right of the socket.
In the embodiment of Figures 3 to 5, the shutters 34 of the three pin socket are of a generally conventional kind, in which the insertion of the earth pin caused the shutter to slide upwardly, in a pair of guide channels 36, against the action of a centrally mounted spring (not shown). This moves the wings 38 of the shutter upwardly, so as to open the apertures for the insertion of the live and neutral pins of the plug. However, the housing is also formed with additional pairs of guide grooves 40 to allow the incorporation of a more sophisticated shutter mechanism of the kind illustrated in Figure 6. This is designed to provide an interlock between the shutter member 42 and an alternative form of rocker arm 44, so that the mains switch will be automatically returned to the "off' position, if the plug is removed without the user switching off the supply first. Similarly, the supply cannot be switched on again, unless a plug has been inserted.
This arrangement works in the following way: in addition to conventional "wings" 38 for closing the live and neutral pin apertures, the shutter also comprises a frame structure 46 which extends upwardly and outwardly from each side of the shutter and cooperates with the guide grooves 40, and also with a separate interlock member 48 which is adapted to engage beneath the lower edge of the corresponding end of the rocker member 44.
As will be appreciated from the drawing, the rocker arm 44 of the Figure 6 embodiment is considerably longer than the rocker arm 24 of the embodiment shown in Figure 3 to 5, so that one end fits into each of its associated end brackets 30 and 32, rather than being "reversible" as in the case of rocker arm 24. In order to enable an actuating member to be positioned at either the "inboard" or the "outboard" position, the rocker arm 44 is provided with a pair of upwardly and downwardly extending wings 50, 52 at each end. A suitably formed operating member (not shown) which has co-operating downwardly and upwardly extending channels on its rear surface, can be slid onto the wings, from the "inboard" side, to occupy an actuating position at the desired end of the rocker arm 44. It will be appreciated that in use, the actuating member will then be effectively located in position, by a correspondingly shaped aperture in the front plate, after assembly of the complete socket.
The outwardly extending structures 46 of the shutter are each arranged to co-operate with an interlocking member 48 which, in turn, engages with the operating member 12 or 14, in such a way that the operating member can only be moved to the on position when a plug has been inserted, that is to say, when the interlocking members 48 are in their disengaged positions, as explained in more detail below. When the plug is removed, the shutter mechanism moves downwardly, under its spring loading, and the corresponding movement of the interlocking members 48 causes the rocker arm 44, which is also spring loaded, to revert to the "off" position.
Once again, as in the case of the embodiment of Figures 3 to 5, it will be appreciated that this construction can also provide a single socket having alternative actuator member positions at either side of the socket, together with an interlocking mechanism between the shutter and the actuator member. Because of the symmetrical construction of the actuator member 44 the interlocking mechanism is particularly reliable, and unlikely to become jammed, because the operating forces on the sliding and rotating parts are completely balanced, relative to the centreline of the socket, and the correspondingly centrally mounted switch mechanism 54.
Figures 7 to 11 illustrate the operation of the switch contacts and interlock mechanism in more detail.
Figure 7 shows the switch mechanism in the 'ON' position, in which movable contact 50 is brought into contact with fixed contact 52 by a conventional overcentre action, when the rocker arm 44 has moved the plunger 22 to its upper rotational position. Similarly, when plunger 22 is moved to its lower rotational position by movement of the rocker arm in the opposite direction, the movable contact 50 is disengaged from the fixed contact as shown in Figure 8 so that the switch is "OFF".
Figure 9 shows the position of the interlock mechanism in the "OFF" condition, i.e. with the shutter closed. The shutter frame 46 carries an enlarged extension 54 at its upper end forming an abutment which faces a corresponding projection 56 on the interlock member 48 when the shutter is down. This blocks the movement of the lower end of the operating member 12 towards the "ON" position.
When the shutter slides to the upward position shown in Figure 10, on the other hand, following the insertion of a mains plug, a recess 58 in the extension of the shutter frame is brought into alignment with the projection 56 so that the extension no longer blocks movement of the interlock member This allows the operating member 12 to be moved to the "ON" position as shown in Figure 11.
It will also be apparent from Figure 11 that when the plug is subsequently withdrawn from the socket, the switch will be automatically returned to the "OFF" position, because the recess 58 is shaped so as to provide as sloping cam surface 60 which urges the projection 56 outwardly, as the shutter frame 46 slides downwardly.

Claims

A switched socket outlet comprising a housing containing at least one switch contact mechanism in a predetermined position, and a corresponding actuating mechanism including an operating member characterised in that the operating member is adapted be mounted in alternative locations relative to the housing.
A switched socket outlet according to claim 1 in which the actuating mechanism includes a reversible rocker arm carrying the operating member at one end.
A switched socket outlet according to claim 1 in which the actuating mechanism includes a rocker arm having a mounting for an operating member at at least two alternative positions so that the operating member can be mounted at one of the positions.
A switched socket outlet according to any preceding claim in which the housing can be fitted with alternative front panels formed with openings corresponding to the different positions of the operating member.
A switched socket outlet according to any preceding claim further comprising a spring-loaded movable safety shutter which is adapted to co-operate with the pins of a mains plug and also with the switch mechanism in such a way that the operating member is locked into the "off' position in the absence of the plug.
A switched socket outlet according to claim 5 in which the shutter carries an abutment member which is moved to a position in which it blocks movement of the switch operating member towards the "ON" position when the shutter is closed, in the absence of the plug, and is moved to an alternative position in which it releases the operating member when a plug is inserted so as to open the shutter.
A switched socket outlet according to claim 5 or claim 6 in which the shutter carries a cam surface which coacts with the operating member to return it to the "OFF" position when the plug is removed.