GB2580435A

GB2580435A - Safety plug

Info

Publication number: GB2580435A
Application number: GB1901213.7A
Authority: GB
Inventors: Stephen Tetlow Luke
Original assignee: Lst Engineering Ltd
Current assignee: Lst Engineering Ltd
Priority date: 2018-12-28
Filing date: 2019-01-29
Publication date: 2020-07-22
Also published as: GB201918917D0; WO2020136580A1; GB201901213D0; GB2580543A; GB201821280D0

Abstract

An electrical plug 1 comprises a body, neutral pin 10, live pin 12, live and neutral terminals 2, 3, and a first openable connection (51, Figure 2) between one of the terminals and an inner end of the corresponding pin. Preferably, there is a first openable connection between the live terminal and live pin, and a second openable connection between the neutral terminal and neutral pin. The connection is held in an opened position preventing operation of the plug, and may be biased towards the opened position by biasing means 6. Actuation means 5, which may comprise a physical or magnetic key 4, a locking mechanism (13, Figure 15) or combination lock (15, Figure 16), close the connection between the terminal and pin, allowing operation of the plug. An electrical plug in which one or more pins are movable such that the pins are misaligned with a socket, and a further electrical plug comprising a retractable pin or shaft movable such that it blocks the plug from being inserted into a socket, are also provided.

Description

TITLE Safety Plug

FIELD OF INVENTION

The present invention relates to electrical plugs for use with sockets. The invention is particularly useful with conventional mains plugs and sockets but can be utilised with substantially any electrical plug and socket combination.

BACKGROUND

Many electrical apparatus require connection to an electrical supply, either to power the apparatus during normal use or to charge the apparatus when battery power has become depleted. Electrical power is normally obtained from a mains electrical supply or other electrical supply from a power socket. Apparatus can be connected to the electrical supply by means of a plug inserted into the power socket.

At present there is no product or plug design, being a mains plug or other similar plug, wherein the plug itself can be locked or otherwise temporarily put in a non-functioning state stopping someone taking an electrical appliance to an uncovered live socket and plugging it in. There are only addition products that are added to the plug. Providing such a plug would be advantageous as it would provide extra safety to potentially dangerous electrical devices such as hand blender, hair straighteners, power tools etc. This would be mainly to prevent injury to children and even teenagers who may be old enough to find and understand the use of the electrical device but may not fully understand the dangers of its use.

Once a plug is locked the appliance would no longer cause electrical or physical danger as no current could flow beyond the plug, or the plug simply could not be able to be plugged into a live socket and therefore could not be used This would mean no more need to lock away or hide possible dangerous electrical appliances as it would not be possible to use the appliance without first unlocking the attached plug. In most cases this would be only a very low-cost modification but provide ultimate protection from unwanted users. Never again would you have to worry about potentially dangerous electrical items being used unsupervised There are many safety devices for electrical plugs and socket but all of these require a product to be added to the plug or socket that prevents its use. The present invention provides a lockable plug that can be locked in a non-functioning state so that it cannot be used, thus no extra device is needed and the plug can be simply locked by a mechanism built into the plug body. In embodiments of the invention is not necessary to have a key that could be lost, there could be a child lock feature built into the plug or a combination design fitted or any other mechanism for temporarily locking the plug in a non-functioning state

SUMMARY OF INVENTION

A first aspect of the present invention provides an electrical plug for connection to an electrical cable and socket comprising: a body; a live pin extending from the body; a neutral pin extending from the body; a live terminal for connection to a live wire located within the body; a neutral terminal for connection to a neutral wire located within the body; a first openable connection either between the live terminal and an inner end of the live pin located within the body or between the neutral terminal and an inner end of the neutral pin located within the body; and an actuation means for closing the first openable connection; wherein in a rest state of the electrical plug the first openable connections is held in an opened position.

That is, in a rest state one of the neutral or live pins is disconnected, thereby rendering the plug non-functional. This can prevent a user operating any apparatus that is connected to the plug. This can be particularly beneficial for any potentially hazardous apparatus that might cause harm to a child or other user.

However, as will be readily appreciated, if only one of the live or neutral pins is disconnected there remains a possibility that a user may be exposed to an electric shock. Therefore, it is preferable that in a rest state both the live and the neutral terminals are disconnected. Thus in a preferred embodiment of the first aspect of the invention the plug comprises: a first openable connection between the live terminal and an inner end of the live pin located within the body; and a second openable connection between the neutral terminal and an inner end of the neutral pin located within the body; wherein when operated the actuation means acts to close the first and second openable connections; and in a rest state of the electrical plug the first and second openable connections are held in an opened position.

This embodiment is advantageous in that it is only when the first and second openable connections are closed by the actuation means that the plug will operate. In a rest state the plug will not operate and will not pose a risk to a user. Further, as both the neutral and the live pins are disconnected a user cannot get an electric shock.

In embodiments of the invention the first and/or the second openable connections may be biased towards the opened position by biasing means. Suitable biasing means will be apparent to the person skilled in the art and include, but are not limited to, springs and other similar components.

In embodiments of the invention the actuating means is a key that is removably insertable into the body, such that when the key is inserted into the body it acts to close the first openable connection and the second openable connection (if present) and when the key is removed from the body the biasing means acts to open the first openable connection and the second openable connection (if present). For example, the key may be a cooperatively formed component that fits into a receiving aperture formed within the body of the plug.

In embodiments of the invention wherein the actuating means is a key, the key may physically press on the first openable connection and the second openable connection Of present) when inserted into the body. Alternatively, the key may act magnetically on the first openable connection and the second openable connection (if present) when inserted into the body.

In embodiments of the invention the actuating means may be a lock mechanism formed within the body of the plug. Any suitable lock mechanism apparent to the person skilled in the art may be used. A lock mechanism may be key operated or may be a combination lock mechanism that is operated by a switch or button In embodiments of the invention the actuating means may be a child safety switch, lock or process A second aspect of the present invention provides an electrical plug for connection to an electrical cable and socket comprising: a body; a live terminal for connection to a live wire located within the body; a neutral terminal for connection to a neutral wire located within the body; a live pin extending from the body; and a neutral pin extending from the body; wherein in a first position the pins are aligned for use with a cooperating socket; one or more pins of the plug is movable between the first position and a second position in which the one or more of pins is misaligned with the cooperating socket; and the one or more pins can be locked in the second position.

In the second aspect of the invention the pins may be misaligned in any manner apparent to the person skilled in the art. For example, the pins may be twisted, rotated, laterally moved between a first position and a second position. This may be achieved in any manner apparent to the person skilled in the art.

A third aspect of the present invention provides an electrical plug for connection to an electrical cable and socket comprising: a body; a live terminal for connection to a live wire located within the body; a neutral terminal for connection to a neutral wire located within the body; a live pin extending from a first side of the body; a neutral pin extending from the first side of the body; and a retractable pin/shaft located in the body of the plug; wherein the retractable pin/shaft is movable from a first position in which it is positioned substantially within the body and a second position in which it extends from the first position within the body to the second position blocking the plug from being inserted into the socket.

In the third aspect of the invention the retractable pin/shaft can prevent the plug being inserted into a socket when it is in the second position. The retractable pin/shaft can be moved from the second position to the first position. When the retractable pin/shaft is in the first position in which it is positioned substantially within the body the plug may be inserted into a socket.

In embodiments of the third aspect of the invention it may be advantageous that the retractable pin/shaft can be locked in the second position This can be achieved using any suitable locking means.

As will be readily appreciated, any embodiment of a plug according to the present invention may comprise an earth pin in addition to the live and neutral pins. If a plug according to the present invention comprises an earth pin it may additional comprise an earth terminal located within the body for connection to an earth wire.

Further any embodiment of the present invention may be formed in the manner of any pin, standard or otherwise, that is currently in use. In advantageous embodiments of the present invention the plug is formed in the manner of a standard mains plug as used in any country or region of the world.

Further features and advantages of the present invention will be apparent from the specific description set out below.

Drawings Figures 1 shows a first embodiment of a first aspect of the present invention; Figures 2 shows a basic electrical schematic of Figure 1 of the present invention; Figures 3 shows an alternative embodiment of a first aspect of the present invention; Figures 4 shows a basic electrical schematic of Figure 3 of the present invention; Figures 5 shows an alternative embodiment of a first aspect of the present invention; Figures 6 shows an alternative embodiment of a first aspect of the present invention; Figures 7 shows a basic electrical schematic of Figure 5 of the present invention; Figures 8 shows a basic electrical schematic of Figure 6 of the present invention; Figures 9 shows a basic electrical schematic of an alternative embodiment of a first aspect of the present invention; Figures 10 shows a basic electrical schematic of an alternative embodiment of a first aspect of the present invention; Figures 11 shows a basic electrical schematic of an alternative embodiment of a first aspect of the present invention; Figures 12,13 and 14 shows a further alternative embodiment of a first aspect of the present invention; Figures 15 shows show an alternative embodiment of a first aspect of the present invention; Figures 16, 17 and 18 show alternative embodiments of a first aspect of the present invention; Figure 19 show an embodiment of a second aspect of the present invention; Figure 20 shows a further embodiment of a second aspect of the present invention; Figure 21 shows a further embodiment of a second aspect of the present invention; Figure 22 shows a further embodiment of a second aspect of the present invention, Figure 23 shows a further embodiment of a second aspect of the present invention; and Figure 24 shows a combination of embodiments one and two of the present invention; and Figure 25 shows an embodiment of a third aspect of the present invention; An embodiment of the first aspect of the present invention consists of a basic UK plug 1 with a natural pin 10, an earth pin 11 and a live pin 12. In this embodiment, only live and neutral terminals 2, 3 being disconnected. Figures 1 shows such an embodiment, which is a very basic design for the UK standard plug 1 but could be modified to suit any standard plug from any country. The main features of this design are a removeable key 4 that could be made from any material and be any shape. Once inserted into the plug 1 it pushes an actuation means 5 in to place and locks it there which closes the live and neutral terminals 2, 3. Once removed a spring 6 causes the actuation means 5 to return to its beginning position disabling the plug 1 and live and neutral terminals 2, 3. In the top drawing of Figure 1, the plug 1 is shown without the removeable key 4 inserted, in this position a circuit of the plug 1 is open and no power could flow. The bottom image shows the plug 1 with the removeable key 4 inserted, pushing the actuation means 5 in to place closing the live and neutral terminals 2, 3. In this position the live and neutral terminals 2, 3 are connected to the live and neutral pins respectively and power could flow from a socket.

Figure 2 shows a basic electrical schematic for Figure 1. Consisting of neutral pin 10, earth pin 11 and live pin 12. The new terminals 2 and 3 and the openable connections 51, depicted as a basic switch symbol all with in the plug boundary 50.

Figures 3 shows an alternative embodiment with live, neutral and earth terminals 2, 3, 7 all disconnected in the top drawing. In Figure 3 top drawing, actuation means 5 is in a first position in which the live, neutral, and earth terminals 2, 3, 7 are disconnected from their respective pins and power cannot flow. In Figure 3 bottom left the live, neutral, and earth terminals 2, 3, 7 are connected with their respective pins and power can flow. The actuation means 5 of this embodiment consists of a sliding/moving block with conducting strips mounted thereon. However, it is to be understood that an actuation means 5 can be formed in any appropriate manner.

Figure 4 shows a basic electrical schematic for Figure 3. Consisting of neutral pin 10, earth pin 11 and live pin 12. The new terminals 2, 3 and 7. The openable connections 51, depicted as a basic switch symbol all with in the plug boundary 50.

Figure 5 shows an alternative embodiment showing a plug 1, same as Figure 1, except with only the live terminal having an openable connection with new terminal 2.

Figure 6 shows an alternative embodiment showing a plug 1, same as Figure 1, with only the neutral terminal having an openable connection with new terminal 3 Figure 7 shows a basic electrical schematic for Figure 5. Consisting of neutral pin 10, earth pin 11 and live pin 12. The new terminal 2 The openable connection 51, depicted as a basic switch symbol all with in the plug boundary 50 Figure 8 shows a basic electrical schematic for Figure 6. Neutral pin 10, earth pin 11 and live pin 12. The new terminal 3. The openable connection 51, depicted as a basic switch symbol all with in the plug boundary 50.

Figure 9 shows a basic electrical schematic for a 2-pin plug. Consisting of neutral pin 10 and live pin 12. The new terminal 2 and 3. The openable connections 51, depicted as a basic switch symbol all with in the plug boundary 50.

Figure 10 shows a basic electrical schematic for a 2-pin plug. Consisting of neutral pin 10 and live pin 12. Only the new live terminal 2. The openable connection 51, depicted as a basic switch symbol is only between the live connection. All with in the plug boundary 50.

Figure 11 shows a basic electrical schematic for a 2-pin plug. Neutral pin 10 and live pin 12. Only the new live terminal 2. The openable connection 51, depicted as a basic switch symbol is only between the live connection. All with in the plug boundary 50.

In an alternative embodiment shown in Figures 12 to 14, a removeable key 14 can act magnetically. There is a magnet 8 located in the actuation means 5 of the plug 1. A removeable magnet key 14 is used to move the actuation means 5 into position using a magnetic force thought an outer wall of the plug 1. A groove 9 is formed in a side of the plug 1 from which the live, neutral, and earth pins 10, 11, 12 protrude to allow the removeable magnet key 14 to be appropriately positioned and moved. Many variations to this can be achieved, When used the magnetic key 14 is slid into the groove 9 formed in the plug 1 which attracts the magnet 8 in the actuation means within the plug 1. The magnetic key 14 is slid into a position in which it is held in in position by the groove 9 thereby moving the actuation means 5 to complete the circuit within the plug 1. In particular, as shown in Figure 6, the magnetic key 14 is positioned in a lower end of the groove 9 and then moved upwards towards the earth pin 12. At an upper end of the groove 9 the magnetic key 14 is held in position by the groove 9. Importantly there is no physical connection between the magnetic key 14 and the magnet 8 within the actuation means 5, rather the magnetic key 14 acts on the magnet 8 through a wall of the plug 1.

Figures 15 shows an alternative embodiment of a plug 1 in which a locking key (not shown) that is not left fitted to the plug 1 is used to lock the plug 1. This is achieved using a suitable locking mechanism 13 formed in the plug 1. The locking mechanism 13 will act to move the actuation means 5 when operated. In such an embodiment a spring or returning mechanism is not an essential feature, the locking mechanism 13 can be either open or closed. In the embodiment of Figures 15 the locking mechanism is a rotatable cylinder lock that is attached to the actuating means 5 by means of a pivot rod 40. In a first position shown in the top image of Figure 15 the locking mechanism 13 is in a first rotational position that acts on the actuation means 5, via the pivot rod 40, to hold the actuation means in an open position. In a second position shown in the bottom drawing of Figure 15 the locking mechanism 13 is in a second rotational position that acts on the actuation means 5, via the pivot rod 40, to hold the actuation means in a closed position. As will be readily appreciated, a key (not shown) is required to move the locking mechanism 13 from the first rotational position to the second rotational position.

A further alternative embodiment is shown in Figure 16 in which a combination lock 15 is used to open and close the live, neutral, and earth connections 2, 3, 7. A plug 1 with a combination lock 15 that has an activation feature like a switch or button 16 that can only be activated once the correct combination is applied. Once applied the plug 1 can be activated so the circuits can be closed and the current can flow from the pins 10, 11, 12 to a device. No need for any key but still fully prevents the plug 1 from drawing power from a socket even when plugged in. This may be a good option for a replacement plug 1 sold as a single item. The combination lock 15 is preferably located on the same side of the plug 1 as the pins 10, 11, 12 to avoid anyone being able to switch off the plug 1 whilst it is plugged in to a socket as this could cause an electrical arc.

In a further alternative embodiment shown in Figures 17 a child safety mechanism 17 is used with no removeable or external key required. Like the combination lock 15 of the previous embodiment there is a safety switch 18 attached that could only be activated if a set process was completed. This could be a force that needs to be applied to a switch 18 before it could slide.

As shown in Figure 18, there also could be a hidden release button 19 located somewhere on the plug 1 that has to be pressed first before the switch could be activated. The main benefit of this embodiment is that the plug 1 would be in an unusable state with no power until an activation process is completed that would activate the plug 1, allowing power to flow and allowing it to be used. Only the person who owns the plug 1 will know the sequence or how to activate the plug 1 and would not be an obvious method a child could figure out. This is similar to the lid of a bleach bottle (not shown) that has to be forced down before it can be turned or a safety lighter (not shown) that has a switch that needs to be pressed before it can be lit. As will be readily understood, there are many ways in which such a child safety mechanism could be implemented.

According to a second aspect of the invention a plug 1 may comprise one or more pins 10, 11, 12 that can be moved from a first position in which they are aligned with a socket to a second position in which they are misaligned with the socket.

As shown in Figure 19, one method is a tilting pin 10 that when locked cannot be straightened so cannot be plugged into a plug socket. This design could be applied to any live and neutral mains plug 1 from any country. This same principle could also tilt the live pin 11 and even both the live pin 11 and the neutral pin 12 at the same time.

In the embodiment of Figure 19 a locking mechanism 13 is provided. The locking mechanism is a rotational cylindrical lock that can be moved through from a first rotational position shown in the larger of the left-hand images to a second rotational position shown in the larger of the right-hand images.

A first embodiment is shown in the upper two of the larger images of Figure 19. In this embodiment only the neutral pin 10 is tilted. The neutral pin 10 is biased towards a usable position in which it is aligned with a socket and the neutral pin 10 is pivotally mounted within the plug 1 at an inner end. When the locking mechanism 13 is in the first rotational position a tab 41 on the locking mechanism acts on the inner end of the neutral pin 10 to tilt it out of the usable position. When the locking mechanism 13 is in the second rotational position the tab 41 on the locking mechanism 13 is moved out of engagement with the inner end of the neutral pin 10 and the neutral pin returns to the usable position.

A second embodiment is shown in the two larger images of Figure 20. In this embodiment both the neutral pin 10 and the live pin 11 are tilted. The neutral pin 10 and the live pin 11 are biased towards a usable position in which they are aligned with a socket and the neutral pin 10 and the live pin 11 are pivotally mounted within the plug 1 at an inner end. When the locking mechanism 13 is in the first rotational position two tabs 41 on the locking mechanism acts on the inner end of the neutral pin 10 and the inner end of the live pin 11 respectively to tilt the pins out of a usable position. When the locking mechanism 13 is in the second rotational position the two tabs 41 on the locking mechanism 13 are moved out of engagement with the inner end of the neutral pin 10 and the inner end of the live pin and the pins return to the usable position.

In a similar manner to the first aspect of the invention and as shown in Figure 21 the neutral pin 10 may be locked in the second position by means of a child safety mechanism 17 including a switch 18 and a side activation button 19 or any other suitable child safety mechanism. In the embodiment of Figure 21 a switch 18 operated by a child safety button 19. In a first position, shown in the left-hand of the large images a tab 41 on the switch 18 acts to tilt the neutral pin 10 out of a usable position in a similar manner to the embodiments of Figure 19. When the side activation button 19 is pressed the switch 18 can be moved upwards to move the tab 41 out of engagement with the neutral pin 10 to allow it to move back to the usable position. The neutral pin 10 is biased towards a usable position in which it is aligned with a socket and the neutral pin 10 is pivotally mounted within the plug 1 at an inner end.

In addition, or instead of tilting the or each pins 10, 11, 12, the or each pin 10, 11, 12 may be twisted. This is shown in the embodiment Figure 22 in which a single pin 10 is twisted. That is, another method of locking the plug 1 would be if one or more of the pins 10, 11, 12 were rotational. In a locked position the pin 10, 11, 12 would be angled so that it could not be inserted into a live socket until the activation process is completed. In the embodiment of Figure 22 the activation mechanism is a locking key 21 with meshing gears that turn the pin 10 within a body of the plug 1. The pin 10 cannot be straightened until a key is used. A potential issue with this design is that it would only work on mains plugs from countries with rectangular/square pins not circular.

In a further embodiment of the invention shown in Figure 23 a locking mechanism of a plug 1 comprises a slidable lid 22 that is locked in position using two rubber blocks 23. When locking in position the neutral pin 10 is locked in an angled position and the plug 1 cannot be used. To unlock and use the plug 1 an operator has to squeeze the lid 22 and a base 24 of the plug, forcing the lid 22 from a first position into a second position in which it presses against the rubber blocks 23. This motion straightens the neutral pin 10 and allows the plug Ito be inserted into a socket. As the rubber blocks 23 act to bias the lid 22 to the first position an external force is necessary to hold the lid 22 in the second position. This means that in order to insert the plug 1 into a socket it is necessary to be squeezing the plug to move the lid 22 into the second position whilst doing so. This is a child locking process that keeps the plug 1 locked from use until the process is activated.

In particular, when the lid 22 is slid from a first position, shown in the central image of the top row, to a second position in the image marked 'X', shown in the top right of the bottom 4 drawings, two prongs 45 formed on the lid 22 push into the rubber blocks, thereby providing a resistance to the movement of the lid 22. The lid 22 has protrusion 46 that act to rotate the neutral pin 10 as the lid 22 is moved from the first position to the second position. The first position is also illustrated in the bottom left-hand image of Figure 22 and the second position is illustrated in the right-hand image of Figure 22.

As will be readily appreciated by the person skilled in the art, there are many different designs that will achieve the aims of the present invention. Further, unless otherwise indicated by context all the locking methods in the first aspect of the invention can be modified and used in the second aspect. Further any embodiment of the first aspect may be combined with any embodiment of the second aspect of the present invention. This can be done in any manner apparent to the person skilled in the art.

A further embodiment of the second aspect of the invention is shown in Figure 24. This embodiment is essentially a combination of the embodiments of Figure 22 and of Figures 15. A rotational locking mechanism 21 acts, via a pivot rod 40, to move an actuation means 5 from a first position in which a circuit is open to a second position in which the circuit is closed. In addition, the same locking mechanism 21 acts to rotate the neutral pin 10 from a first rotational position in which it is rotationally misaligned with a socket to a second rotational position in which it is rotationally aligned with a socket.

In a third aspect of the present invention a retractable pin/shaft 30 is used to prevent a plug 1 being inserted into a socket. Figure 25 shows an embodiment of a plug 1 where a modification to the plug base 31 to add a pivot pin 30 that is activated using a side lock 32. When the lock 32 is activated to pivot pin 30 that is connected via a shaft 33 turns 90 degree out of the base 31 and protruded from a face of the base 31. While this pin 30 is in the locked position the plug 1 cannot be plugged into a socket. Only when the side lock 32 is deactivated dose the pin 30 return within the base 31 and the plug can be used. This could also be a spring-loaded pin that protruded vertically or for an American plug could be on a sliding switch.

The above description of specific embodiments is not intended to be limiting. Rather, they are illustrative of the concepts of the present invention only. The skilled person will readily appreciate which features of each embodiment can be combined with other embodiments. The scope of the invention is defined in the claims.

Claims

CLAIMS1 An electrical plug for connection to an electrical cable and socket comprising: a body; a live pin extending from the body; a neutral pin extending from the body, a live terminal for connection to a live wire located within the body; a neutral terminal for connection to a neutral wire located within the body; a first openable connection either between the live terminal and an inner end of the live pin located within the body or between the neutral terminal and an inner end of the neutral pin located within the body; and an actuation means for closing the first openable connection; wherein in a rest state of the electrical plug the first openable connections is held in an opened position.
2 An electrical plug according to claim; 1, comprising: a first openable connection between the live terminal and an inner end of the live pin located within the body; and a second openable connection between the neutral terminal and an inner end of the neutral pin located within the body, wherein when operated the actuation means acts to close the first and second openable connections; and in a rest state of the electrical plug the first and second openable connections are held in an opened position
3 An electrical plug according to claim 2, wherein the first and second openable connections are biased towards the opened position by biasing means
4 An electrical plug according to claim 3, wherein the actuating means is a key that is removably insertable into the body, such that when the key is inserted into the body it acts to close the first and second openable connections and when the key is removed from the body the biasing means acts to open the first and second openable connections
5. An electrical plug according to claim 4, wherein the key physically presses on the first and second openable connections when inserted into the body.
6. An electrical plug according to claim 4, wherein the key acts magnetically on the first and second openable connections when inserted into the body.
7 An electrical plug according to claim 1 or claim 2, wherein the actuating means is a lock mechanism formed within the body of the plug.
8. An electrical plug according to claim 7, wherein the lock mechanism is key operated.
9. An electrical plug according to claim 7, wherein the lock mechanism is a combination lock mechanism that unlocks the plug.
10. An electrical plug according to claim 1 or claim 2, wherein the actuating means is a child safety switch, lock or mechanical process.
11. An electrical plug according to any preceding claim, further comprising an earth pin extending from the body.
12. An electrical plug according to claim 11, further comprising an earth terminal located within the body for connection to an earth wire
13 An electrical plug for connection to an electrical cable and socket comprising: a body; a live terminal for connection to a live wire located within the body, a neutral terminal for connection to a neutral wire located within the body; a live pin extending from the body; and a neutral pin extending from the body; wherein in a first position all pins of the plug are aligned for use with a cooperating socket; one or more pins of the plug is movable between the first position and a second position in which the one or more of pins is misaligned with the cooperating socket; and the one or more pins can be locked in the second position.
14 An electrical plug for connection to an &ectrical cable and socket comprising: a body; a live terminal for connection to a live wire located within the body; a neutral terminal for connection to a neutral wire located within the body; a live pin extending from a first side of the body; a neutral pin extending from the first side of the body; and a retractable pin/shaft located in the body of the plug; wherein the retractable pin/shaft is movable from a first position in which it is positioned substantially within the body and a second position in which it extends from the first position within the body to the second position extending from the first side of the body thereby blocking the plug from being inserted into the socket.
15. An electrical plug according to claim 14, wherein the retractable pin/shaft can be locked in the second position.
16. An electrical plug according to claim 13, wherein the movement of the pin is achieved by a child safety switch, lock or mechanical process.
17. An electrical plug according to claim 14 or claim 15, wherein the movement of the retractable pin/shaft is achieved by a child safety switch, lock or mechanical process.
18. An electrical plug according to claim 13, wherein the lock mechanism is a combination lock mechanism that unlocks the plug.
19 An electrical plug according to claim 13 or claim 14, wherein the method used to move the one or more pins or the retractable pin/shaft from the first position to the second position is one or more of the physical insertion of a key into the body of the plug; a combination or key-operated lock mechanism formed in the body of the plug; or child safety switch, lock or mechanical process.
20. An electrical plug according to claim 1, 13 or 14 further comprising a locking mechanism that allows the plug to be locked in a non-functional state.