GB2268840A

GB2268840A - Devices for use with multi-pin plugs and sockets

Info

Publication number: GB2268840A
Application number: GB9313874A
Authority: GB
Inventors: Richard Stanley Amor
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-07-04
Filing date: 1993-07-05
Publication date: 1994-01-19
Anticipated expiration: 2013-07-05
Also published as: GB2268840B; GB9313874D0

Abstract

A device for use with a multi-pin plug or socket comprises a moulded plastic disc (10), the centre portion of which is formed with an array of apertures (30) positioned to receive the plug terminals. The disc (10) is provided with markings to identify the colours of the wires to be fitted to the plug and socket terminals and is formed integrally with a sleeve(11) which is a close fit in the cylindrical portion of a socket. A cutout(12) on the sleeve (11) defines the angular position of the device on a socket. <IMAGE>

Description

DEVICES FOR USE WITH MULTI-PIN PLUGS AND SOCKETS Field of the Invention This invention relates to devices for use with multi-pin electrical plugs and sockets, for example, the standard sevenpin plugs and sockets which are used to connect the power supply of an agricultural tractor to a trailer vehicle so as to provide power for the tail lights, indicator lights and brake lights of the trailer vehicle. Similar seven-pin plugs and sockets are also used in connection with the towing of caravans and between lorries and trailer vehicles.

It is obviously important that, when wiring a multi-pin plug or socket, the correct wires should be connected to each of the plug and socket terminals and it is an object of the present invention to provide a device which is so designed as to facilitate the correct wiring of a multi-pin plug or socket.

It is a further object of the present invention to provide a device which can be used to ensure the rapid identification of each of the terminals of a multi-pin plug or socket.

A standard seven-pin socket used for, for example, agricultural vehicles comprises a moulded plastics body which includes a generally cylindrical portion within which the array of seven terminals is located and the body carries a springloaded cover which, when the socket is not connected to a plug, closes the open end of the cylindrical portion to protect the terminals. The reverse side of the body includes a well within which the ends of the terminals are located, which terminal ends are provided with screw-threaded fasteners for holding the wires securely in contact with the terminals.

It is an object of one specific aspect of the present invention to provide a device for use with a seven-pin socket to facilitate identification of the socket terminals either when viewed from the front thereof, for example, when testing circuits connected to the socket, or when viewed from the reverse thereof, i.e. when connecting wires to the terminals.

A standard seven-pin plug used with such a socket also comprises a moulded plastics body which includes a generally cylindrical portion within which the array of seven complementary terminals is located and the arrangement is such that the cylindrical portion of the plug can be fitted into the cylindrical portion of the socket to cause interengagement of the terminals, the spring-loaded cover of the socket including a lug formation which engages behind a flange of the plug when the terminals are fully interengaged.

A further object of the present invention is the provision of a device for use with a seven-pin plug to facilitate identification of the plug terminals either for testing the circuits connected to the plug or for wiring the plug.

It is to be appreciated that, although specific reference has been made to seven-pin plugs, the invention is of application to plugs and sockets having any number of pins and terminals.

Summary of the Invention According to the present invention there is provided a device for use with a multi-pin plug or socket, which device comprises a disc of such size and shape that it can either engage with a cylindrical portion of the socket or fit on to the terminals of the plug, which disc is marked so as to provide indications of the colours of the wires to be connected to the terminals of the plug or socket and of the functions of the circuits connected to said terminals.

If the disc is intended to engage with a cylindrical portion of the socket, the disc is preferably formed integrally with a sleeve which is a close fit in the cylindrical portion of the socket, the sleeve being provided with a locating formation shaped for cooperation with a locating formation of the socket such that the disc can be engaged with the socket in only one angular position of the disc relative to the socket.

If the disc is intended to be engaged with the terminals of the plug, the disc will be formed with an array of apertures positioned so as to receive the plug terminals, the disc preferably being marked so as to indicate the angular orientation at which it is to be engaged with the plug.

The disc may be intended to be engaged alternatively with either the cylindrical portion of the socket or with the terminals of the plug. In such case, the disc will be formed with an integral sleeve and with an array of apertures, each as specified above.

The disc, if intended to be used with the socket, may be sold or supplied in combination with the socket and will be of such size that, when the spring-loaded cover has been pivoted clear of the terminals to allow the disc to be placed in position, the disc and cover will interengage in such manner that the cover serves to hold the disc in position while the disc serves to maintain the cover in its open position.

Brief Description of the Drawings Figure 1 is a plan view of a disc for use in the manner described above, Figure 2 is an underneath plan view of the disc, and Figure 3 is a side view of the disc.

Description of the Preferred Embodiment The disc 10 shown in the drawings is formed as a plastic moulding and is printed or otherwise marked to provide the colours and indications mentioned below.

The disc 10 is intended to be used for the wiring, testing and terminal identification of a standard seven-pin socket or plug and is of generally annular form. The annular disc 10 is formed integrally with a cylindrical sleeve 11 which is formed with a cut-out 12. The angular position of the cutout 12 is appropriately related to the markings on the disc 10 to ensure that, when the disc 10 is engaged with a plug or socket, as explained below, the markings on the disc 10 are in register with the correct terminals of the plug or socket The sleeve 11 is intended to fit within a cylindrical well of the seven-pin socket around the array of seven terminals. The socket has a locating formation in the form of a lug which extends inwardly from a wall of the well at a position diametrically opposite to the pivot mounting for the dust cover of the socket.This locating formation is provided to ensure that, when a plug is engaged with the socket, the plug and socket are in the required angular alignment and, when the sleeve 11 fits within the well of the socket, the cut-out 12 receives the inwardly projecting lug.

The dust cover for the socket is spring-loaded and the disc 10 is of such size that, when the sleeve 11 is fully engaged within the well of the socket, an edge of the disc 10 diametrically opposite to the cut-out 12 engages beneath a rib of the spring-loaded cover to hold the cover in its fully open position.

The disc 10 is marked on each of its sides to indicate the colours of the wires which are to be connected to the terminals and the associated circuit functions. The markings are as shown in the drawings. The marking for terminal 1, to which a yellow wire is connected, is indicated as 20. In the wiring diagram, this wire is referred to as L and the associated circuit is that of the left-hand indicator of the trailer. The marking 20 for terminal 1 thus comprises a yellow sector 21, the terminal number 1, the letter L and the circuit identification L. H. INDICATOR.

The markings for the other terminals are spaced angularly around the disc 10 and are repeated on both sides of the disc 10, that for the centre terminal being of less angular extent than the markings for the other terminals. Each marking includes a coloured sector, with the colours corresponding to the colours of the wires connected (or to be connected) to the respective terminals. By providing the markings on both sides of the disc 10, terminal identification is facilitated when viewed from either front or rear of the socket. Wiring and testing of the socket circuits can thus readily be effected with minimum risk of error.

The disc 10 can also be used when wiring the plug terminals. The centre portion of the disc 10 is provided, as shown, with an array of apertures 30 whose size and spacing correspond to those of the plug terminals. The plug insert is separated from the body of the plug and is placed above the disc 10, with the terminals appropriately oriented, and the terminals are then pressed into the apertures 30.

When the plug insert is in position, the end formations of the terminals (to which the wires are to be connected) project through the apertures 30 and are disposed adjacent the appropriate colour code markings. The likelihood of incorrect wiring is thereby reduced or avoided.

The disc 10 can be used for a number of other purposes, in addition to wiring of the plug or socket. For example, the disc can be engaged with the terminals of a plug on a trailer lighting circuit for checking the continuity of the trailer lights. The sleeve 11 will be located on the side of the disc 10 remote from the plug and will serve to protect the protruding pins against short circuits while the test is being carried out.

To test the voltages of the circuits of the socket of a towing vehicle, the disc 10 is engaged with the socket so that the sleeve 11 fits within the socket. The markings on the disc 10 thus identify the circuits of the towing vehicle to facilitate testing thereof. The disc 10 again serves to reduce the risk of short circuits while the testing is being carried out.

In a similar way, the disc 10 can be engaged with the pins of a plug on a trailer. The terminals of the plug pass through the apertures 30 in the disc and the markings on the disc 10 thus identify the trailer circuits being tested.

In a modified form of disc, specifically for use with a plug, the sleeve 11 is omitted and the disc, with markings as described above, is then used for identifying the plug circuits when carrying out testing or rewiring operations.

It is to be appreciated that the detailed description given above is by way of example only and that many variations or modifications thereof can be effected without departing from the scope of the invention as defined in the appended claims.

Claims

Claims:

1. A device for use with a multi-pin plug or socket, which device comprises a disc of such size and shape that it can either engage with a cylindrical portion of the socket or fit on to the terminals of the plug, which disc is marked so as to provide indications of the colours of the wires to be connected to the terminals of the plug or socket and of the functions of the circuits connected to said terminals.

2. A device as claimed in Claim 1, and for engagement with a cylindrical portion of a socket, in which the disc is formed integrally with a sleeve which is a close fit in the cylindrical portion of the socket.

3. A device as claimed in Claim 2, in which the sleeve is provided with a locating formation for cooperation with a locating formation of the socket such that the disc can be engaged with the socket in only one angular position of the disc relative to the socket.

4. A device as claimed in Claim 1, and for engagement with the terminals of a plug, in which the disc is formed with an array of apertures positioned so as to receive the plug terminals, the disc being marked so as to receive the plug terminal.

5. A device as claimed in Claim 4, in which the disc is marked so as to indicate the angular orientation at which it is to be engaged with the plug.

6. A device as claimed in Claim 1, in which the disc is formed integrally with a sleeve for fitment in the cylindrical portion of a socket and with an array of apertures positioned so as to receive the terminals of a plug.

7. A device for use with a multi-pin plug or socket, said device being constructed substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

8. A method of testing the wiring of a multi-pin plug or socket which comprises the use of a device as claimed in any one of the preceding claims.

9. A method of identifying the terminals of a multi-pin plug or socket which comprises the fitment of a device as claimed in any one of Claims 1 to 7 to the plug or socket.