GB1587197A - Electrical connector - Google Patents

Description

(54) ELECTRICAL CONNECTOR (71) We, IJJCAS INDUSTRIES LIMITED, a British Company of Great King Street, Birmingham, B19 2XF, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to electrical connectors and is particularly concerned with electrical connectors of the type which are mounted on a tractor unit of an articulated road vehicle or on a road goods vehicle or private motor car con verted to tow a caravan or other trailer, to enable electrical connection to be made to lamps on the caravan or other trailer.

It is common practice to use a so-called seven-pin electrical connector assembly which consists of a socket connector having seven male pins mounted on the tractor unit and an electri cal connector plug mounted on the trailer unit for connection to the socket connector when the trailer unit is connected up to the tractor unit.

In the electrical connector assembly two of the pins are employed as a power supply to res pective direction indicator lamps on the trailer unit and another of the connector pins is em ployed for earth return from the direction indi cator lamps, the stop lamps and the tail lamps of the trailer unit. The remaining pins in the con nector are used as current supply for the stop lamps and the tail lamps and for an auxiliary power supply, such as for internal lighting pur poses.

A flasher device is provided on the tractor unit to turn the direction indicator lamp on and off at the required rate when the direction indi cator switch is operated.

This is effected using a coil-operated, make and-break mechanism operates depending upon the state of an electronic circuit. The coil of a second coil-operated, make-and-break mechanism carries the lamp filament current which is switched by the first mechanism and the mech anism is mechanically set such that it will oper ate when all the direction indicator lamps on one side of the tractor unit are flashing but will not operate when the coil current is reduced due to the failure of one or more of the filament lamps on that side of the vehicle. The contacts on this second, mechanism influence the state of the electronic circuit such that when the second mechanism is operating, the first mechanism is operating at a rate of about 90 cycles/ minute but when the second mechanism is not operating due to the failure of a lamp filament, the first mechanism operates at a significantly increased rate.

When a trailer unit is connected, the second make-and-break mechanism is reset such that again it will operate when all the lamps, on one side of the tractor/trailer, combination are flashing, but will not operate when one or more of the lamps have failed. The mechanism is reset electrically by using a "back off' coil which opposes the main coil, which is now carrying increased lamp current, until the resultant magnet field is effectively as before.

In order to ensure that the back-off coil is only brought into circuit when the trailer unit is connected it is normally necessary to provide an electrical connector assembly having an extra pin, namely an eight-pin electrical connector assembly. This is inconvenient as it does not allow the use of a standard seven-pin electrical connector plug of the trailer unit.

An object of the present invention is to obviate or mitigate the above disadvantage in a neat and economical fashion.

According to the present invention there is provided an electrical connector comprising a body having a recess at one end portion thereof for receiving a complementary connector, a plurality of elongate electrical connector elements mounted in spaced relationship in the recess to project from the bottom of the recess towards the open end of the recess, and terminals electrically connected with the connector elements to enable said elements to be connected to electrical leads, wherein at least one of the connector elements has two conductive portions which are electrically insulated from each other, and each conductive portion is connected to a respective one of the terminals.

In this manner, only seven electrical connector pins need be provided in the connector so that a standard seven-pin connector can be provided on the trailer unit; the complementary cor nector pin which engages said at least one of the connector pins serves to bridge the two conductive portions thereof so that the two terminals associated with the two conductive portions are interconnected. Thus, one of these terminals can be used as the earth return for the direction indicator lamps inter alia, and the other terminal can be connected with the back-off coil whereby the back-off coil is only connected to earth when the trailer unit is connected up to the tractor unit.

Preferably, the connector pins of the electrical connector are of the male type.

Also according to the present invention there is provided an electrical connector assembly comprising an electrical connector as defined in the last preceding paragraph but two in combination with a complementary electrical connector engaged with said electrical connector, said complementary electrical connector having a connector element which engages the or a respective one of said at least one of the connector elements so as to connect electrically the said two conductive portions thereof.

The present invention has the advantage that, with very slight modification, a standard sevenpin, tractor unit-mounted electrical connector can be employed.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a front view of an electrical connector according to the present invention, Figure 2 is a side view of the electrical connector of Figure 1, and Figure 3 is a view of one of the connector pins of the electrical connector illustrated in Figures 1 and 2, shown partly in axial section.

Referring to the drawings, the electrical connector illustrated therein is for mounting on a motor car converted to tow a caravan or other light trailer or niutatis mutandis on the tractor unit of an articulated road vehicle and forms part of an electrical connector assembly of which the other part is a completely standard seven-pin complementary electrical connector which is mounted on the trailer unit of the articulated road vehicle. The electrical connector comprises a die-cast metal sleeve 10 with integral mounting flange 11, an apertured electrically insulating bush 12 mounted in the sleeve 10 so that the sleeve 10 and bush 12 together define a recess 13 of circular cross-section in one end portion of the sleeve 10, the base of the recess 13 being defined by one end of the bush 12.

Like the sleeve 10, the bush 12 is of circular cross-section and has seven axially extending bores therethrough in which are located respective electrical pins P which extend upwardly from the base of the recess 13 towards the open end of the sleeve 10. As can be seen in Figure 1, the arrangement and sizes of the pins P correspond exactly to the arrangement and size of the pins in a conventional seven-pin electrical connector and the bush 12 has the numbers 1 to 7 marked thereon (as shown in Figure 1) which is the standard coding for the individual pins P to enable the electrical pins P to be wired in accordance with international coding. Pins 1, 2, 4, 5, 6, and 7 are completely standard pins in that they each have a continuous, electrically conductive surface exposed within the recess 13. Each of these completely standard pins is provided with a completely standard terminal 14 mounted externally at the opposite end of the sleeve 10 to the open end thereof. The electrical pin P which is cose numbered 3 in the case of caravans (as shown) or 1 in the case of commercial vehicles, on the bush 12 is not a standard pin and takes the form illustrated in Figure 3. Referring now particularly to Figure 3, the pin P illustrated therein comprises an electrically conductive end portion 15 having a shank 16 extending integrally and axially therefrom to terminate in a screw-threaded portion 17 which projects externally of the sleeve 10 at the end thereof at which the terminals 14 are provided. This pin also comprises an electrically conductive sleeve 18 which is mounted on the shank 16 but electrically insulated therefrom by an electrically insulating sleeve 19. In an alternative embodiment (not shown) instead of the electrically insulating sleeve 19, there may be provided a pair of cup-shaped insulating members disposed at opposite ends of the sleeve 18 and arranged to hold the latter in spaced relationship from the shank 16. The inner end of the end portion 15 and the outer end of the sleeve 18 are electrically insulated from each other by an electrically insulating spacer 20a mounted on the shank 16. Thus, within the recess 13 in the sleeve 10, the electrical connector pin P code numbered 3 (or 1 as the case may be) has two conductive portions defined by portion 15 and part of the sleeve 18 electrically insulated from one another. The sleeve 18 projects externally of the sleeve 10 to terminate in an externally screw threaded portion 20. The screw threaded portions 17 and 20 provide respective terminals for the end portion 15 and sleeve 18. A nut 21 and washers 22 are mounted on the screw threaded portion 20 whilst nuts 23 and washers 24 are mounted on the screw threaded portion 17. An insulating washer 25 serves to prevent the washers 24 from coming into electrical contact with the adjacent end of the screw threaded portion 20. As can be seen from Figure 2, a connector 26, which can be crimped to a bared end of a lead (not shown), is mounted on the screw threaded portion 20 and firmly secured in position by tightening down nuts 21 so that the connector 26 is electrically connected with the sleeve 18. A further connector 27 is mounted on the screw threaded portion 17 and firmly located in position between the nuts 23 and washers 24 so that the connector 27 is electrically connected with the end portion 15. In the illustrated embodiment, the connector 27 takes the form of an annular flange through which the screw-threaded portion 17 passes, panda U-shaped part integral with the flange. The U-shaped part is crimped to the bared end of a lead wire in use. However, the connector 27 may alternatively take the form of a conventional "bullet" connector engaged over the portion 17 and being received, in use, in a female connector to which a lead is electrically connected.

A pair of apertured lugs 28 are provided on the flange 11 and are integral therewith. A cover plate (not shown) is pivotally mounted on the flange 11 by way of the lugs 28 in a manner well known with this type of electrical connector. The cover plate serves to close off the recess 13 to prevent ingress of moisture and dirt when the complementary connector is not inserted into the recess 13 and also serves to prevent accidental disengagement of the electrical connector and complementary electrical connector when mutually engage, also in a manner well known with this type of electrical connector assembly.

The complementary electrical connector, i.e.

the electrical connector mounted on the trailer unit is of a completely standard and well known type which consists basically of a plug having a series of seven female-type connector pins which are coded 1 to 7 and engage over the respective pins P in use. All of the female-type pin connectors of the complementary connector are simply in the form of plain sleeve so that, when the female-type pin connector coded 3 of the complementary connector engages over the male-type pin connector P coded 3 (or 1 as the case may be) of the illustrated electrical connector, the end portion 15 is electrically connected with the sleeve 18 whereby the connectors 26 and 27 are electrically interconnected. In this embodiment, connector 26 is connected with the bared end of a lead to earth whereby all of the lights in the trailer unit are connected with the tractor unit earth when the electrical connections are made.

The terminal 27 is connected to a bared end of a lead connected with the back-off coil previously mentioned in this specification. Thus, when the complementary connector is not engaged in the electrical connector illustrated in the drawings, the electrical circuit through the back-off coil is not made but when the complementary connector is engaged in the electrical connector, the connectors 26 and 27 are interconnected thereby completing the circuit through the back-off coil for the purpose mentioned in the preamble to the specification.

In the above description, the code numbering in relation to the connector assembly for use on a combination of towing vehicle and caravan or light trailer corresponds to the code numbering in British Standards Institution BS AU 149: 1969.

It is to be appreciated that the present invention is not restricted to the use of the electrical connector, and an assembly including the electrical connector in conjunction with the directior indicator circuitry of a tractor/trailer combination but may also be used, for example, in conjunction with the automatic switching off of high intensity rear lamps on the tractor unit when the trailer unit is coupled thereto so that only high intensity lamps on the trailer unit are brought into operation under, for example, foggy conditions.

WHAT WE CLAIM IS: 1. An electrical connector comprising a body having a recess at one end portion thereof for engaging a complementary connector, a plurality of elongate electrical connector elements mounted in spaced relationship in the recess to project from the bottom of the recess towards the open end of the recess, and terminals electrically connected with the connector elements to enable said elements to be connected to electrical leads, wherein at least one of the connector elements has two conductive portions which are electrically insulated from each other, and each conductive portion is connected to a respective one of the terminals.

2. An electrical connector as claimed in Claim 1, wherein the connector elements of the electrical connector are of the male type.

3. An electrical connector assembly comprising an electrical connector as claimed in Claim 1 or Claim 2, in combination with a complementary electrical connector engaged with said electrical connector, said complementary electrical connector having a connector element which engages the or a respective one of said at least one of the connector elements so as to connect electrically the said two conductive portions thereof.

4. A connector element substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. through which the screw-threaded portion 17 passes, panda U-shaped part integral with the flange. The U-shaped part is crimped to the bared end of a lead wire in use. However, the connector 27 may alternatively take the form of a conventional "bullet" connector engaged over the portion 17 and being received, in use, in a female connector to which a lead is electrically connected. A pair of apertured lugs 28 are provided on the flange 11 and are integral therewith. A cover plate (not shown) is pivotally mounted on the flange 11 by way of the lugs 28 in a manner well known with this type of electrical connector. The cover plate serves to close off the recess 13 to prevent ingress of moisture and dirt when the complementary connector is not inserted into the recess 13 and also serves to prevent accidental disengagement of the electrical connector and complementary electrical connector when mutually engage, also in a manner well known with this type of electrical connector assembly. The complementary electrical connector, i.e. the electrical connector mounted on the trailer unit is of a completely standard and well known type which consists basically of a plug having a series of seven female-type connector pins which are coded 1 to 7 and engage over the respective pins P in use. All of the female-type pin connectors of the complementary connector are simply in the form of plain sleeve so that, when the female-type pin connector coded 3 of the complementary connector engages over the male-type pin connector P coded 3 (or 1 as the case may be) of the illustrated electrical connector, the end portion 15 is electrically connected with the sleeve 18 whereby the connectors 26 and 27 are electrically interconnected. In this embodiment, connector 26 is connected with the bared end of a lead to earth whereby all of the lights in the trailer unit are connected with the tractor unit earth when the electrical connections are made. The terminal 27 is connected to a bared end of a lead connected with the back-off coil previously mentioned in this specification. Thus, when the complementary connector is not engaged in the electrical connector illustrated in the drawings, the electrical circuit through the back-off coil is not made but when the complementary connector is engaged in the electrical connector, the connectors 26 and 27 are interconnected thereby completing the circuit through the back-off coil for the purpose mentioned in the preamble to the specification. In the above description, the code numbering in relation to the connector assembly for use on a combination of towing vehicle and caravan or light trailer corresponds to the code numbering in British Standards Institution BS AU 149: 1969. It is to be appreciated that the present invention is not restricted to the use of the electrical connector, and an assembly including the electrical connector in conjunction with the directior indicator circuitry of a tractor/trailer combination but may also be used, for example, in conjunction with the automatic switching off of high intensity rear lamps on the tractor unit when the trailer unit is coupled thereto so that only high intensity lamps on the trailer unit are brought into operation under, for example, foggy conditions. WHAT WE CLAIM IS:

1. An electrical connector comprising a body having a recess at one end portion thereof for engaging a complementary connector, a plurality of elongate electrical connector elements mounted in spaced relationship in the recess to project from the bottom of the recess towards the open end of the recess, and terminals electrically connected with the connector elements to enable said elements to be connected to electrical leads, wherein at least one of the connector elements has two conductive portions which are electrically insulated from each other, and each conductive portion is connected to a respective one of the terminals.

2. An electrical connector as claimed in Claim 1, wherein the connector elements of the electrical connector are of the male type.

3. An electrical connector assembly comprising an electrical connector as claimed in Claim 1 or Claim 2, in combination with a complementary electrical connector engaged with said electrical connector, said complementary electrical connector having a connector element which engages the or a respective one of said at least one of the connector elements so as to connect electrically the said two conductive portions thereof.

4. A connector element substantially as hereinbefore described with reference to the accompanying drawings.