GB2480867A

GB2480867A - Electrical power lead

Info

Publication number: GB2480867A
Application number: GB201009371A
Authority: GB
Inventors: Anthony Hines
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-04
Filing date: 2010-06-04
Publication date: 2011-12-07
Also published as: GB201009371D0

Abstract

An electrical Power lead for an electrical appliance comprises a cable 11 having a connector 14 secured to one end thereof. The cable includes live and neutral conductors 15, 17 and the connector includes live and neutral connector terminals (24, 25, Fig 2) coupled to those respective conductors. The electrical power lead also includes an adaptor 71 provided with mains power connection means 74, 75, 76 for engagement with a mains power supply terminal specific to the territory in which the appliance is to be used. The connector and the adaptor are configured to interconnect the cable to the mains power connection means. Optionally, the electrical power lead may be furnished with retention means adapted to prevent inadvertent disconnection of the connector and the adaptor, and the connector may include means to change the voltage and/or rectify AC to DC.

Description

ELECTRICAL POWER LEAD

The present invention relates to a power ead for an electrica appance and in particular to a power lead that includes a standard connector for use in any country.

Most electrical appliances include an electrical power cable having a plug fitted to its free end for connection to the socket of a power point. There are at least thirteen different types of plugs and power sockets adopted around the world so the particular type of plug fitted to the appliance depends on the type of power socket adopted by the country to which the appliance is to be shipped. As such, each appliance produced by a manufacturer and intended for worldwide to distribution must be available in thirteen different models, each mode having a different type of plug. This can add increased strain to many manufacturers as it causes greater financia and logistical burdens, particuarly for smaller manufacturers with limited resources.

n an ideal world, al countries would adopt a common pug and power socket so that only one model of appliance would be required for worldwide distribution, rather than thirteen. However, in view of the number of appiances already in circulation with a particuar type of plug and the number of buildings fitted with corresponding power sockets, any proposed change is unlikely to be welcome since the replacement of plugs and power sockets could be highly inconvenient and expensive.

ft is a principal object of the present invention to provide a solution to the above problem borne by eectrical appliance manufacturers, by providing a solution that does not require the replacement of existing power sockets and plugs on existing appiances.

According to the invention, there s provided an electrical power lead for an electrical appance, the lead comprising: -a cable having a live conductor and a neutral conductor; -a connector secured to the cable and including: a live connector terminal electrically coupled to the live conductor and defining a live connector contact; and a neutral connector terminal electrically coupled to the neutral conductor and defining a neutral connector contact; and -an adaptor comprising: mains power connection means for engagement with a mains power supply terminal specific to the territory in which the appliance S to be used; a live adaptor terminal electrically coupled to the main power connection means and defining a live adaptor contact; and a neutral adaptor terminal electrically coupled to the main power connection means and defining a neutral adaptor contact, whereby the connector and the adaptor are configured to interconnect so as to cause the live connector contact to be electrically coupled to is the live adaptor contact and also to cause the neutral connector contact to be electrically coupled to the neutral adaptor contact.

Preferably the connector may also include an earth connector terminal defining an earth connector contact and the cable may also include an earth conductor electrically connected to the earth connector terminal. This is particularly advantageous when the electrical power lead is to be used with appliances requiring an earth connection.

In one arrangement the electrical power lead may also comprise retention means adapted to prevent the connector and the adaptor being inadvertently disconnected. The retention means may include an elastically deformable member provided on one of the adaptor and the connector and which engages a suitably profiled portion provided on the other of the adaptor and the connector.

Engagement of the member and the profited portion may occur automaticay as the adaptor connects to the connector but disengagement of those parts to permit disconnection of the adaptor and the connector may require manual release. The retention means may instead comprise fasteners, such as screws to effect a more secure connection between the adaptor and the connector.

Preferably there is also provided aUgnrnent means to permit interconnection of the connector and the adaptor only when the contacts of the connector are properly aligned with the respective contacts of the adaptor. This ensures that the live contact terminal always connects to the live adaptor termina' rather than to the neutral adaptor terminaL The agnment means may comprise any feature provided on the connector and the adaptor that permits connection of those parts in only one orientation. For instance, each connector contact may be a uniquely shaped pin and each adaptor contact may be a uniquely shaped recess arranged is to receive the corresponding pin. Alternatively, the connector may include a rectangular block having the connector contacts arranged in a row along its upper face and the adaptor may include a rectangular socket having a row of adaptor contacts arranged along its upper face for engagement with the row of connector contacts.

In one arrangement, the adaptor includes a cover configured to shield the adaptor contacts when not engaged by the connector contacts so as to prevent young children directly or indirectly touching the adaptor contacts and potentially getting an electric shock. The cover may include a panel arranged to move between an open position whereat the adaptor contacts are accessible and a closed position whereat the adaptor contacts are concealed. The panel may be biased towards its closed position when the connector and adaptor are disconnected and which may be manual'y urged to the open position against the bias to permit the connector to be connected. Alternatively, the cover could be removed automaticaUy as the connector and adaptor are interconnected.

Advantageously, the adaptor may include a switch to control the flow of electrica' current to the adaptor contacts.

Most countries of the world supply single phase mains AC electrical power at around 230 volts and at 50Hz, but there are a small selecUon of countries and regions where electncal power is supplied at around 120 volts and at 60Hz, io including Canada, US, Central America, parts of South America and ndonesia.

So as to avoid damaging appliances designed to run off mains AC power at 120 volts, those appliances should be clearly labeUed as such. In one embodiment of the invention, the adaptor or the connector may include a transformer for adjusting the voltage of electricity transmitted from the mains power supply to the is conductors. Most preferably, the transformer comprises a step-down transformer disposed within the adaptor for reducing the voltage across the adaptor contacts.

Additionally or alternatively, there may also be provided a converter for converting the mains AC electricity to DC electricity.

Further, the end portions of the conductors may be secured to the terminals by screws or alternative means. For instance, each termina' may comprise a metallic block having a bore to which a screw threadingly engages, and each conductor may be clamped between the block and the screw. Alternatively, each connector may include a metallic surface and the conductor is clamped between that surface and part of the connector. In a different arrangement, the terminals include metallic surfaces to which the conductors are soldered.

By way of example only, one embodiment of the present invention will now be described in detail, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a cable and a connector assembly forming part of the invenUon; Figure 2 is a perspective view of the cab'e and part of the connector shown in Figure 1; Figure 3 is a perspective view of the cable and connector assembly shown in Figure 1, but with the lid of the connector removed; Figure 4 is a perspective view of the lid; io Figure 5 is a perspective view of an adaptor; Figure 6 is a perspective view of an adaptor fitted with the connector and cab'e assembly of Figures 1 to 4; Figure 7 is a perspective view of a second embodiment of the adaptor; and Figure 8 is a perspective view of a third embodiment of the adaptor.

is Referring initially to Figure 1, there is shown an assembly, genera'ly indicated 10, comprising a cable 11 having a first end 1 2 adapted to connect to an electrical app'iance (not shown) and a second end 13 secured to a connector 14.

A cable Ii of this type is well known in the art and consists of a live conductor 15 provided with a brown insulating sleeve 16, a neutral conductor 17 provided with a blue insulating sleeve 18 and an earth conductor 19 provided with a green and yellow insulating sleeve 20, the three conductors 1 5,17,19 being bound together in an outer insulating sheath 21. The cable 11 is selected according to the power consumption of the electrical appliance (not shown) so as to ensure that the cable 11 can safely carry the maximum current drawn by the appliance.

Referring to Figures 1 and 2, there are shown three terminals 24,25,26 each comprising a rectangular body having a cavity (not shown) in one of its end faces 27,28,29 for receiving a bare end of a conductor 15,17,19 and a threaded bore (not shown) in its upper face 31,32,33 arranged to intersect the cavity. A screw 35,36,37 threadingly engages each bore so as to clamp the conductor 15,17,19 in place and provide a good electrical contact between the conductor and the terminal 25,25,26. A flange 40,41,42 depends downwardly from the lower face of the body so as to define a contact surface 44,45,46. The left hand terminal 25 is connected to the neutral conductor 17, the middle terminal 24 connects to the live conductor 15 and the right-hand terminal 26 connects to the earth conductor 19.

As best shown in Figures 3 and 4, the connector 14 comprises a rectangular body having a base 50, side waU 51 upstanding from the base and a lid 52 adapted to rest on the top of the side wa to enclose an interior is compartment. Two partitions 54 upstand from the base 50 to define, in combination with the sidewall 51, three ceUs for accommodating the three terminals 24,25,26. Three openings (not shown) are formed through the base 50 of the connector 14 in the region of the ces such that the flanges 40,41,42 of the terminals project through the openings when located in their cells. The width of each opening corresponds to its respective cell and is sized to form a snug fit with the flange 40,4 1,42.

A recess 55 is formed through the side wall 51 at the rear end to define a cable guide through which the cable 11 extends when the lid 52 is fitted and the cable 11 is connected to the terminals. The cable is clamped to the base 50 by a bar 56 located adjacent the inside face of that end wall 51. The lid 52 includes a peripheral lip 58 that rests on the upper surface of the side waH 51, part of the id bcating inside the compartment. The lower face of the id bears against the upper face of the terminals 24,25,26 so as to prevent displacement of the terminals during use. The lid is secured to the connector body by screws 60.

The connector 14 is also furnished with a locking mechanism 65 to prevent inadvertent removal of the connector from a receptacle 70 (discussed in more detail below in relation to Figure 5). The locking mechanism 65 includes an arm having a forward portion 66 mounted to an exterior face of the side walt 51 of the connector 14 and a rear portion 67 that extends rearwardly and outwardly from the io forward portion 66. A recess 68 is provided on an outer face of the arm for engagement with a projection (not shown) provided in the socket 70.

Referring now to Figures 5 and 6, there is shown an adaptor 71 for interfacing the cable and connector assembly 10 with a conventional UK mains power supp'y socket (not shown). The adaptor 71 comprises a body 72 having a is front face 73 from which three pins 74,75,76 extend for engagement with three correspondingly shaped and spaced openings (not shown) provided on a conventional UK mains power supply socket. Provided on the lower wall of the body is the receptacle 70 for receiving the connector 14 and which has a cross-section corresponding to that of the connector so as to form a snug fit therewith.

In this embodiment the receptacle is generally rectangular and has three channels 80,81,82 defined in one surface for receiving the three flanges 40,41,42 of the three terminals 2425,26 and a single channel 85 in an adjacent side for receiving the arm of the locking mechanism 65.

The left hand channel 81 includes a metallic strip (not shown) electrically connected through the inside of the body 73 to the neutral pin 74, the middle channel 80 includes a metallic strip (not shown) electrically connected through the inside of the body 73 to the live pin 75 and the right hand channel 82 includes a metallic strip (not shown) electrically connected through the inside of the body 73 to the earth pin 76. In this way, when the connector 14 is inserted into the socket 70 and each contact 44,4546 engages its respective strip, an electrical path is created between the neutral conductor 17 and the neutral pin 74, the live conductor 15 and the live pin 75 and also the earth conductor 19 and the earth pin 76.

The single channel 85 includes a formation (not shown) arranged for io cooperation with the locking mechanism 65. Specifically, as the connector 14 is inserted into the receptacle 70 the arm slides through the single channel 85 and deflects inwardly as it rides over the formation. When the connector 14 is fully inserted into the receptacle 70 the formation aligns with and locates in the recess 68 and the arm returns to its usual position. To withdraw the connector 14 from is the receptacle 70, the rear portion 67 of the arm must be urged towards the connector 14 so as to disengage the formation from the recess 68.

The cable connector assembly 10 is intended for use with many different types of adaptors 71 having differently configured pins 74,75,76. For instance, any appliance fitted with the standard cable connector assembly 10 described above may be operated in a country other than the UK by using an adaptor configured specifically for the mains power supply sockets of that country. Figure 7 shows a different second embodiment of adaptor 90 that may be used to interface the cable connector assembly 10 with a European mains power supply terminal since it includes the standard receptacle 70 for receiving the connector 14 and also the pins 91,92 and rebates 93,94 for cooperation with that mains power supp'y terminaL indeed, a range of adaptors cou'd be provided so that any appance fitted with the above described cab'e connector assemb'y 10 may be used in any country.

In some instances it is necessary to a'ter the vo'tage of the eectrica power transmitted to the app'iance, possib'y because the app'iance was designed in the US and thus requires 120 vo'ts, or possibly because it is a iow power appliance.

n that case a third embodiment of adaptor 100 (shown n figure 8) incorporating an appropriate'y configured step-down transformer (not shown) shou'd be used to interface the cable connector assemb'y 10 to the mains power supp'y.

Claims

CLAtMS 1. An electrical power lead for an electrical appliance, the lead comprising: -a cable having a live conductor and a neutral conductor; -a connector secured to the cable and including: a live connector terminal electrically coupled to the live conductor and defining a live connector contact; and a neutral connector terminal electrically coupled to the neutral conductor and defining a neutral connector contact; and -an adaptor comprising: mains power connection means for engagement with a mains power supply terminal specific to the territory in which the appliance is to be used; a live adaptor terminal electrically coupled to the main power io connection means and defining a live adaptor contact; and a neutral adaptor terminal electrically coupled to the main power connection means and defining a neutral adaptor contact, whereby the connector and the adaptor are configured to interconnect so as to cause the live connector contact to be electrically coupled to the live adaptor contact and also to cause the neutral connector contact to be electrically coupled to the neutral adaptor contact.
2. An electrical power lead as claimed in claim 1, wherein the connector also includes an earth connector terminal defining an earth connector contact.
3. An electrical power lead as claimed in claim 2, wherein the cable includes an earth conductor electrically connected to the earth connector terminal.
4. An electlcai power lead as claimed In any preceding claim and further comprising retention means adapted to prevent the connector and the adaptor inadvertently being disconnected.
5. An electrical power lead as claimed in any preceding claim, and further comprising alignment means to permit interconnection of the connector and the adaptor only when the contacts of the connector are properly aligned with the respective contacts of the adaptor.
6. An electrical power lead as claimed In any preceding claims, wherein one of the connector contacts and the adaptor contacts comprise pins and the other of the connector contacts and the adaptor contacts at least partially define a socket for receMng the pIns and creatIng an electrical connection between those parts.
7. An electrical power lead as claimed in any preceding claim, wherein one of the connector and the adaptor defines a recess In which at least a portion of the other of the connector and adaptor locates.t An electrical connector as claimed In any precedIng claim, whereIn the adaptor Includes a cover confIgured to shield the adaptor contact when not engaged by the connector contacts.9. An electrical connector as claimed In any preceding claim and wherein the is configured to alter the voltage of electricity transmitted from the mains power stçpiy to the cable.10. An eectrca connector as daimed in any other c'aim, and further comprising a converter for converting the mains AC electricity to DC electncty.11. An electrical adaptor as claimed in claim 1 and substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.