WO2014045269A1

WO2014045269A1 - Apparatus and a method for preventing unauthorised access to an electrical pin and sleeve socket connector

Info

Publication number: WO2014045269A1
Application number: PCT/IE2013/000019
Authority: WO
Inventors: Gerard Patrick LAMBERT
Original assignee: Lambert Gerard Patrick
Priority date: 2012-09-20
Filing date: 2013-09-20
Publication date: 2014-03-27
Also published as: IES86339B2; GB2520469A; IES20120413A2; GB201504897D0; GB2520469B

Abstract

An assembly (1) comprises a pin and sleeve socket connector (3) and apparatus (5) comprising a closure element (17) engageable with the pin and sleeve socket connector (3) for closing an open mouth (11) of a sleeve (9) of the pin and sleeve socket connector (3) to prevent unauthorised access thereto. The closure element (17) comprises a tubular element (19) defining a hollow interior region (23) which is closed at one end by an end cap (22) and terminates in its other end in an open mouth (24) to the hollow interior region (23). The tubular element (19) is engageable with the pin and sleeve socket connector (3) with a socket block (12) thereof extending through the open mouth (24) of the tubular element (19) into the hollow interior region (23) and with the forward portion (25) of the tubular element (19) located between the socket block (12) and the sleeve (9) of the pin and sleeve socket connector (3). Pincher elements (37) of a clasp (18) engage an eye bracket (33) of the tubular element (19) and embrace a hinge (16) of a closure cap (15) of the pin and sleeve socket connector (3) for securing the closure element (17) in the pin and sleeve socket connector (3). A padlock (45) secures and retains the clasp (18) in the closed state, thereby preventing unauthorised access to the pin and sleeve socket connector (3).

Description

"Apparatus and a method for preventing unauthorised access to an electrical pin and sleeve socket connector"

The present invention relates to apparatus for preventing unauthorised access to an electrical pin and sleeve socket connector. The invention also relates to a method for preventing unauthorised access to an electrical pin and sleeve socket connector. The invention further relates to an assembly comprising the apparatus and an electrical pin and sleeve socket connector. The invention also relates to an electrical pin and sleeve plug connector, and to an assembly comprising the pin and sleeve plug connector and a pin and sleeve socket connector. Further the invention relates to a receiver for attaching to a pin and sleeve plug connector, and to a method for adapting a pin and sleeve plug connector for securing to a pin and sleeve socket connector. Electrical pin and sleeve plug and socket connectors are commonly used in the industrial, commercial and leisure industries, and may be used in both indoor and outdoor locations. For example, in the leisure industry such pin and sleeve socket connectors are provided in caravan parks, marinas and the like. Additionally, such pin and sleeve socket connectors are commonly used to provide a temporary electrical power supply both indoors and outdoors, for example, on a building site. Additionally, such pin and sleeve socket connectors are provided on motor vehicles for providing an electrical power supply from the motor vehicle to a trailed vehicle, for example, a trailer, a caravan, a boat or the like. With the exception of the use of such pin and sleeve socket connectors on motor vehicles, in general, the electrical power supply which is provided by a pin and sleeve socket connector is an AC mains electricity supply, and may be a single phase supply or a three phase supply.

Such pin and sleeve socket connectors comprise a base mounting element which is secured to a wall, a post or other suitable support. A sleeve, typically of circular transverse cross-section extends from the base mounting element and defines a hollow interior region which terminates in an open mouth. A socket block, which in the case of a single phase electrical supply comprises three hollow electrically conductive contact elements, is located concentrically in the hollow interior region defined by the sleeve, and is spaced apart from the sleeve. The three hollow contact elements are configured to receive three corresponding electrically conductive pins of a pin and sleeve plug connector. One of the hollow contact elements of the pin and sleeve socket connector provides a live component of the power supply, another of the hollow contact elements provides a neutral component of the power supply, and a third of the hollow contact elements provides an earth connection. In the case of a three phase electrical supply the pin and sleeve socket connector comprises four hollow electrically conductive contact elements, three of which provide the three phases of the electrical supply and a fourth of which provides a neutral component of the electrical supply

A closure cap is hingedly connected to the sleeve of the pin and sleeve socket connector adjacent the open mouth thereof, and is hingeable between an open state providing access to the hollow interior region, and in turn to the socket block, through the open mouth, and a closed state closing the open mouth. Typically, such closure caps are spring urged into the closed state.

Pin and sleeve plug connectors comprise an elongated sleeve also of circular transverse cross-section which extends between a first end and a second end and defines a hollow interior region. The first end defines an open mouth to the hollow interior region. A pin block is located concentrically within the sleeve spaced apart inwardly from the open mouth. In the case of a pin and sleeve plug connector suitable for a single phase electrical supply three electrically conductive pins are provided extending from the pin block through the hollow interior region towards the open mouth for engaging the corresponding hollow contact elements of a socket block of a pin and sleeve socket connector. A cable from the pin block for carrying the power supply from the three pins of the pin block extends through the hollow interior region and through a cable accommodating opening in the second end of the sleeve. In the case of pin and sleeve plug connectors suitable for a three phase electrical supply four electrically conductive pins extend from the pin block to engage the corresponding hollow contact elements of the pin and sleeve socket connector.

To engage a pin and sleeve plug connector into a pin and sleeve socket connector, the closure cap of the pin and sleeve socket connector is first pivoted from the closed state to the open state. The pin and sleeve plug connector is then engaged in the sleeve of the pin and sleeve socket connector with the sleeve of the pin and sleeve plug connector engaged within the sleeve of the pin and sleeve socket connector and located between the socket block and the sleeve of the pin and sleeve socket connector and with the pins of the pin and sleeve plug connector engaged in corresponding ones of the hollow contact elements in the socket block of the pin and sleeve socket connector. A problem with such pin and sleeve socket connectors is that it is not possible to prevent unauthorised use of the pin and sleeve socket connectors. Thus, unauthorised third parties can gain access to the electrical supply provided by such pin and sleeve socket connectors by merely urging the closure cap into the open state and connecting a suitable pin and sleeve plug connector into the pin and sleeve socket connector. This is undesirable. A further problem with such pin and sleeve socket connectors is that when a pin and sleeve plug connector is legitimately coupled to a pin and sleeve socket connector, an unauthorised third party can readily remove the pin and sleeve plug connector which is legitimately coupled to the pin and sleeve socket connector and couple an unauthorised pin and sleeve plug connector into the pin and sleeve socket connector.

The unauthorised use of such pin and sleeve socket connectors can result in significant unauthorised draw-off of electricity, which in turn can result in significant monetary losses to those providing electricity through such pin and sleeve socket connectors. Additionally, the unauthorised use of such pin and sleeve socket connectors can lead to unsafe practices, thereby raising serious safety issues.

There is therefore a need for a method and apparatus for preventing unauthorised access to an electrical pin and sleeve socket connector, and there is also a need for an assembly comprising such a pin and sleeve socket connector and the apparatus, which addresses at least some of the problems of known pin and sleeve socket connectors. Additionally, there is a need for a pin and sleeve plug connector as well as an assembly of a pin and sleeve plug connector and a pin and sleeve socket connector which addresses at least some of the problems of such pin and sleeve socket connectors.

The present invention is directed towards providing a method and apparatus for preventing unauthorised access to an electrical pin and sleeve socket connector, and the invention is also directed towards providing such a pin and sleeve plug connector, as well as an assembly of such a pin and sleeve plug connector and a pin and sleeve socket connector which addresses at least some of the problems of pin and sleeve socket connectors. The invention is also directed towards a receiver for a pin and sleeve plug connector.

According to the invention there is provided apparatus for preventing unauthorised access to an electrical pin and sleeve socket connector of the type comprising a socket block and a sleeve extending around the socket block and spaced apart therefrom, the apparatus comprising a closure element, the closure element comprising an elongated tubular element extending between a first end and a second end and defining a hollow interior region, the first end defining an open mouth to the hollow interior region, the tubular element being configured to be engageable in the pin and sleeve socket connector with the socket block extending through the open mouth of the tubular element into the hollow interior region thereof and with the tubular element engaged between the socket block and the sleeve of the pin and sleeve socket connector, and a receiver extending outwardly from the tubular member, the receiver being configured to receive a releasable securing means with the securing means releasably retaining the closure element in engagement with the pin and sleeve socket connector.

Preferably, the second end of the tubular element is closed by an end cap.

In one embodiment of the invention the hollow interior region of the tubular element is configured to house a pin block of an electrical pin and sleeve plug connector.

In another embodiment of the invention a pin block of a pin and sleeve plug connector is located in the hollow interior region of the tubular element and is configured to electrically engage the socket block of the pin and sleeve socket connector when the tubular element is engaged in the pin and sleeve socket connector. Preferably, a cable accommodating opening is provided in the tubular element for accommodating an electrical cable from the pin block of the pin and sleeve plug connector. Advantageously, the cable accommodating opening is located adjacent the second end of the tubular element. Ideally, the second end of the tubular element defines the cable accommodating opening.

In one aspect of the invention the receiver comprises an eye bracket defining a receiving opening for receiving the securing means. Preferably, the receiver extends radially from the tubular element. Advantageously, the receiver is non-removably mounted on the tubular element. Ideally, the receiver is mounted fast on the tubular element. Preferably, the receiver is integrally formed with the tubular element.

Advantageously, the receiver is spaced apart from the first end of the tubular element. Preferably, the receiver is located on the tubular element intermediate the first and second ends thereof.

In another aspect of the invention a portion of the tubular element extending from the receiver to the second end of the tubular element is configured for holding and gripping the closure element during insertion thereof into and removal thereof from the pin and sleeve socket connector.

In another aspect of the invention an alignment element is located on the tubular element and is configured to engage a complementary alignment element of the pin and sleeve socket connector for aligning the closure element with the pin and sleeve socket connector. Preferably, the alignment element is located on the tubular element adjacent the first end thereof extending outwardly from the tubular element. Advantageously, the alignment element extends radially outwardly from the tubular element. Preferably, the alignment element is axially spaced apart from the receiver. Advantageously, the alignment element is circumferentially spaced apart from the receiver. Ideally, the alignment element is circumferentially spaced apart from the receiver at an angle of approximately 180°. In another aspect of the invention a stop member is located on the tubular element for engaging the pin and sleeve socket connector with the tubular element engaged in the pin and sleeve socket connector with the socket block located within the hollow interior region of the tubular element and with the tubular element located between the socket block and the sleeve of the pin and sleeve socket connector. Preferably, the stop member is located intermediate the receiver and the first end of the tubular element. Advantageously, the stop member extends outwardly of the tubular element. Preferably, the stop member extends radially outwardly from the tubular element. Ideally, the stop member extends circumferentially around the tubular element.

In one aspect of the invention the tubular element is of circular transverse cross- section. In another aspect of the invention the tubular element comprises one of a plastics material and a metal material. Preferably, the receiver comprises one of a plastics material and a metal material. Advantageously, the alignment element comprises one of a plastics material and a metal material, and is integrally formed with the tubular element. Preferably, the stop member comprises one of a plastics material and a metal material, and is formed integrally with the tubular element.

In another embodiment of the invention the apparatus further comprises the securing means. In one aspect of the invention the securing means comprises a clasp operable between an open state and a closed state, and being configured in the closed state for engagement by a retaining means for retaining the securing means in the closed state. In another aspect of the invention the clasp comprises a pair of pivotally connected pincher elements terminating in respective distal ends, the pincher elements being pivotal between the open state and the closed state, and being configured to embrace a portion of the pin and sleeve socket connector in the closed state for releasably engaging the pin and sleeve socket connector with at least one of the pincher elements engaged in the receiver for preventing removal of the closure element from the pin and sleeve socket connector. Preferably, the pincher elements are configured so that each pincher element engages the receiver in the closed state. Advantageously, the pincher elements are configured to embrace a hinge of the pin and sleeve socket connector which hingedly couples a closure cap to the pin and sleeve socket connector for preventing access to the pin and sleeve socket connector. Preferably, the pincher elements are configured to embrace the hinge of the pin and sleeve socket connector when the closure cap is in an open state with the pincher elements located between the closure cap and the pin and sleeve socket connector. Advantageously, the pincher elements are of arcuate shape. In another aspect of the invention a pair of lugs extend from the respective pincher elements, the lugs being configured for engagement by the retaining means with the pincher elements in the closed state. Preferably, each lug comprises a lock engaging opening, the lock engaging openings of the respective lugs being aligned when the pincher elements are in the closed state for engaging the retaining means for retaining the pincher elements in the closed state. Advantageously, the lugs extend from the pivotal connection connecting the pincher elements on the opposite side of the pivot connection from the side of the pivot connection from which the pincher elements extend. In another embodiment of the invention the apparatus further comprises the retaining means engageable with the securing means. Preferably, the retaining means comprises a padlock.

The invention also provides an assembly comprising an electrical pin and sleeve socket connector, the pin and sleeve socket connector comprising a socket block, and a sleeve extending around the socket block and spaced apart therefrom, and the apparatus according to the invention with the tubular element of the closure element thereof engaged in the pin and sleeve socket connector, with the socket block of the pin and sleeve socket connector extending into the hollow interior region of the tubular element, and with the tubular element located between the socket block and the sleeve of the pin and sleeve socket connector. Further the invention provides an assembly comprising an electrical pin and sleeve socket connector, the pin and sleeve socket connector comprising a socket block, and a sleeve extending around the socket block and spaced apart therefrom, and apparatus for preventing unauthorised access to the pin and sleeve socket connector, the apparatus comprising a closure element, the closure element comprising an elongated tubular element extending between a first end and a second end and defining a hollow interior region, the first end defining an open mouth to the hollow interior region, the tubular element being engaged in the pin and sleeve socket connector with the socket block extending through the open mouth of the tubular element into the hollow interior region thereof, and with the tubular element engaged between the socket block and the sleeve, a receiver extending outwardly from the tubular member, and a securing means releasably engaged with the receiver and with a portion of the pin and sleeve socket connector for releasably retaining the closure element in engagement with the pin and sleeve socket connector.

In one aspect of the invention a pin block of a pin and sleeve plug connector is located in the hollow interior region of the tubular element and is electrically engaged in the socket block of the pin and sleeve socket connector. In another aspect of the invention the receiver comprises an eye bracket defining a receiving opening and the securing means is engaged in the receiving opening.

In another aspect of the invention an alignment element is located on the tubular element and is engaged in a complementary alignment element of the pin and sleeve socket connector for aligning the closure element with the pin and sleeve socket connector.

Preferably, a stop member is located on the tubular element, the stop member engaging the pin and sleeve socket connector.

In a further aspect of the invention the securing means comprises a clasp operable between an open state and a closed state, and being configured in the closed state for engaging a retaining means for retaining the securing means in the closed state. Preferably, the clasp comprises a pair of pivotally connected pincher elements terminating in respective distal ends, the pincher elements being pivotal between the open state and the closed state, and embracing a portion of the pin and sleeve socket connector in the closed state for releasably engaging the pin and sleeve socket connector, and at least one of the pincher elements engaged in the receiver for preventing removal of the closure element from the pin and sleeve socket connector. Advantageously, the receiver is engaged by both of the pincher elements of the clasp in the closed state. In another aspect of the invention the pin and sleeve socket connector comprises a closure cap for preventing access to the pin and sleeve socket connector, the closure cap being hingedly coupled to the pin and sleeve socket connector by a hinge, and the pincher elements of the clasp embrace the hinge of the pin and sleeve socket connector.

Advantageously, the pincher elements of the clasp embrace the hinge of the pin and sleeve socket connector when the closure cap is in an open state with the pincher elements of the clasp located between the closure cap and the pin and sleeve socket connector.

Preferably, a pair of lugs extend from the respective pincher elements of the clasp, the lugs being configured for engagement by the retaining means with the pincher elements in the closed state. Advantageously, each lug comprises a lock engaging opening, the lock engaging openings of the respective lugs being aligned when the pincher elements are in the closed state for engaging the retaining means for retaining the pincher elements in the closed state.

In one aspect of the invention the assembly further comprises the retaining means engaged in the lock engaging openings of the lugs of the securing means. In one embodiment of the invention the retaining means comprises a padlock. Additionally, the invention provides a method for preventing unauthorised access to an electrical pin and sleeve socket connector of the type comprising a socket block and a sleeve extending around the socket block and spaced apart therefrom, the method comprising releasably securing a closure element in the pin and sleeve socket connector, the closure element comprising an elongated tubular element extending between a first end and a second end and defining a hollow interior region, the first end defining an open mouth to the hollow interior region, engaging the tubular element in the pin and sleeve socket connector with the socket block extending through the open mouth of the tubular element into the hollow interior region thereof and with the tubular element engaged between the socket block and the sleeve, and releasably securing the closure element in the pin and sleeve socket connector by a securing means releasably engageable with a portion of the pin and sleeve socket connector and with a receiver extending outwardly from the tubular member. In one embodiment of the invention a pin block of a pin and sleeve plug connector is located in the hollow interior region of the tubular element, and the method further comprises electrically engaging the pin block with the socket block of the pin and sleeve socket connector when the tubular element is being engaged in the pin and sleeve socket connector.

In another aspect of the invention the receiver comprises an eye bracket defining a receiving opening for receiving the securing means.

In another aspect of the invention the method further comprises engaging the securing means with the receiver and with the pin and sleeve socket connector, and engaging the retaining means with the securing means.

The invention also provides an electrical pin and sleeve plug connector comprising a housing, and a receiver extending from an outer surface of the housing for receiving a reieasable securing means to secure and releasably retain the pin and sleeve plug connector in engagement with a pin and sleeve socket connector. In one aspect of the invention the receiver comprises an eye bracket defining a receiving opening for receiving the securing means. Preferably, the eye bracket extends radially from the housing of the pin and sleeve plug connector.

Advantageously, the receiver is substantially non-removably mounted on the housing. Preferably, the receiver is mounted fast on the housing. Advantageously, the receiver is located on the housing intermediate respective first and second ends thereof.

In one embodiment of the invention the receiver is integrally formed with the housing.

In an alternative embodiment of the invention the receiver comprises an abutment means for abutting the housing. Preferably, the abutment means of the receiver comprises a base member configured to engage the outer surface of the housing. Advantageously, the eye bracket extends substantially perpendicularly from the base member.

In a further embodiment of the invention the electrical pin and sleeve plug connector further comprises an attachment means for securing the base member to the housing.

In one aspect of the invention the attachment means comprises an elongated ligature for securing the base member to the housing. Preferably, the receiver defines a ligature accommodating opening for

accommodating the ligature of the attachment means extending therethrough with the ligature extending around the housing for securing the base member to the housing. In one aspect of the invention the ligature comprises a cable tie.

Further the invention provides an assembly comprising an electrical pin and sleeve plug connector according to the invention releasably secured to a pin and sleeve socket connector by a securing means.

In one aspect of the invention the securing means comprises a clasp operable between an open state and a closed state, and being configured in the closed state for engaging a retaining means for retaining the securing means in the closed state.

Advantageously, the assembly further comprises the retaining means engaged with the securing means. The invention also provides a receiver for attaching to a housing of a pin and sleeve plug connector, the receiver being configured to be engageable by a securing means for securing the pin and sleeve plug connector to a pin and sleeve socket connector, and comprising an abutment means for abutting a housing of the pin and sleeve plug connector, and an eye bracket extending from the abutment means and defining a receiving opening therethrough for engagement by the securing means.

Preferably, the abutment means comprises a base member.

In one embodiment of the invention the receiver further comprises an attachment means for securing the abutment means to the housing of the pin and sleeve plug connector.

In one aspect of the invention the attachment means comprises an elongated ligature configured to extend around the housing of the pin and sleeve plug connector.

The invention further provides a method for adapting a pin and sleeve plug connector for securing to a pin and sleeve socket connector by a securing means, the method comprising attaching the receiver according to the invention to a housing of the pin and sleeve plug connector by the attachment means.

The advantages of the invention are many. A particularly important advantage of the apparatus according to the invention is that by inserting and securing the closure element of the apparatus into a pin and sleeve socket connector, unauthorised access to an electrical supply provided to the pin and sleeve socket connector is prevented. A particularly important advantage of the invention is that it allows unauthorised access to the electricity supply of a pin and sleeve socket connector to be prevented without having to retrofit any complex security devices to the pin and sleeve socket connector. The closure element is readily engageable in the pin and sleeve socket connector by merely urging the closure cap of the pin and sleeve socket connector into the open state and engaging the closure element of the apparatus in the pin and sleeve socket connector. Thereafter all that is required is to secure the closure element to the pin and sleeve socket connector with the securing means. The provision of the securing means in the form of a clasp comprising a pair of pivotally coupled pincher elements which embrace a hinge of the closure cap of the pin and sleeve socket connector and engage the receiver of the closure element of the apparatus provides a relatively simple, quick and inexpensive means of coupling the closure element to the pin and sleeve socket connector, which can then be readily secured by a padlock.

A further and particularly important advantage of the invention is achieved when a pin block comprising pins of a pin and sleeve plug connector is located in the hollow interior region of the closure element with a cable extending from the pin block through the closure element, since in this case the closure element effectively becomes a pin and sleeve plug connector, and can thus be secured to a pin and sleeve socket connector to thereby prevent unauthorised removal therefrom. An advantage of providing a pin and sleeve plug connector with the receiver is that the pin and sleeve plug connector can be readily secured to a pin and sleeve socket connector, and unauthorised removal of the pin and sleeve plug connector from the pin and sleeve socket connector is prevented. Similar advantages are achieved by the use of the methods and the assemblies according to the invention as are achieved by the apparatus and the receiver according to the invention.

The invention will be more clearly understood from the following description of some preferred embodiments thereof, which are given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an assembly according to the invention which comprises apparatus also according to the invention for preventing unauthorised access to an electrical pin and sleeve socket connector,

Fig. 2 is a side elevational view of the assembly of Fig. 1 ,

Fig. 3 is a cross-sectional side elevational view of the assembly of Fig. 1 ,

Fig. 4 is an exploded perspective view of the assembly of Fig. 1 , Fig. 5 is a perspective view of a portion of the apparatus of Fig. 1 ,

Fig. 6 is a cross-sectional side elevational view of the portion of Fig. 5 of the apparatus of Fig. 1 , Fig. 7 is a cross-sectional side elevational view of the portion of Fig. 5 of the apparatus of Fig. 1 with the portion of Fig. 5 differently configured,

Fig. 8 is a cross-sectional side elevational view of an assembly comprising the apparatus of Fig. 7 and a pin and sleeve socket connector,

Fig. 9 is a partly cut-away side elevational view of a pin and sleeve plug connector according to the invention, and Fig. 10 is a perspective view of a receiver also according to the invention of the pin and sleeve plug connector of Fig. 9.

Referring to the drawings and initially to Figs. 1 to 6 thereof, there is illustrated an assembly according to the invention, indicated generally by the reference numeral 1 , which comprises an electrical pin and sleeve socket connector, indicated generally by the reference numeral 3, and apparatus according to the invention, indicated generally by the reference numeral 5, for preventing unauthorised access to the electrical pin and sleeve socket connector 3. Before describing the assembly 1 and the apparatus 5 in detail, the electrical pin and sleeve socket connector 3 will first be described.

Referring in particular to Fig. 4, the pin and sleeve socket connector 3 is a conventional pin and sleeve socket connector, which will be well known to those skilled in the art, and comprises a housing 6 having a base mounting element 8 which is adapted for mounting on a wall, post or other suitable support structure. A sleeve 9 of circular transverse cross-section extends from the base mounting element 8 and defines a hollow interior region 10 and terminates in an open mouth 11 to the hollow interior region 10. A socket block 12 is concentrically mounted in the hollow interior region 0 of the sleeve 9 and is spaced apart from the sleeve 9 within the hollow interior region 10. Three spaced apart hollow tubular electrically conductive contact elements 14 are located in the socket block 2 for providing a single phase AC mains electricity supply to corresponding pins of a pin and sleeve plug connector. In this embodiment of the invention the tubular electrical contact elements 14 are configured so that the contact element 14a carries the live component of the electricity supply, the contact element 14b carries the neutral component of the electrical supply, while the contact element 14c provides an earth connection. A closure cap 15 is hingedly coupled to the sleeve 9 by a hinge 16, and is spring urged by a torsion spring (not shown) from an open state illustrated in Fig. 4 providing access to the socket block 12 through the open mouth 11 to a closed state (not shown) closing the open mouth 1 1. Such a pin and sleeve socket connector will be known to those skilled in the art, and further description should not be required. Referring again to Figs. 1 to 6, the apparatus 5 of the assembly 1 for preventing unauthorised access to the pin and sleeve socket connector 3 will now be described. The apparatus 5 comprises a closure element 17 which is engageable with the pin and sleeve socket connector 3 for closing the open mouth 11 thereof in order to prevent unauthorised access to the socket block 12 of the pin and sleeve socket connector 3 in order to prevent unauthorised use of electricity from the pin and sleeve socket connector 3. A securing means, which in this embodiment of the invention comprises a clasp 18, which is described in detail below, releasably secures the closure element 17 to the pin and sleeve socket connector 3. The closure element 17 comprises a tubular element 19 of circular transverse cross- section extending between a first end 20 and a second end 21. The tubular element 19 is closed at the second end 21 by an end cap 22 and defines with the end cap 22 a hollow interior region 23. The first end 20 is open and defines an open mouth 24 to the hollow interior region 23.

A forward portion 25 of the tubular element 19 is of internal and external diameter to extend through the open mouth 11 of the pin and sleeve socket connector 3 into the sleeve 9 between the sleeve 9 and the socket block 12 to a closed state closing the open mouth 11 in order to prevent access to the socket block 2. A stop means, namely, a stop member, which in this embodiment of the invention comprises a stop ring 27 extends circumferentially around the outer surface of the tubular element 19 and is spaced apart from the open mouth 24 such that when the closure element 17 is fully engaged with the pin and sleeve socket connector 3 in the closed state with the forward portion 25 located within the sleeve 9 and between the sleeve 9 and the socket block 12, the stop ring 27 engages the sleeve 9 of the pin and sleeve socket connector 3 adjacent the open mouth 1 .

An alignment element 30 extends radially outwardly from the forward portion 25 of the tubular element 19 adjacent the first end 20 for engaging a corresponding complementary alignment element, namely, an alignment recess 31 formed in the sleeve 9 of the pin and sleeve socket connector 3 for aligning the tubular element 19 with the pin and sleeve socket connector 3. The alignment element 30 extends a short distance along the forward portion 25 of the tubular element 19 from the first end 20.

A receiver comprising an eye bracket 33 is mounted on and extends radially from and longitudinally along the tubular element 19 rearwardly from the stop ring 27. The eye bracket 33 defines a receiving opening 34 which is engageable by the clasp 18 as will be described below. The eye bracket 33 is spaced apart circumferentially around the tubular element 19 from the alignment element 30 an angular distance of approximately 180°, so that when the alignment element 30 is engaged in the alignment recess 31 of the pin and sleeve socket connector 3, the eye bracket 33 is substantially aligned with the hinge 16 for facilitating engagement of the receiving opening 34 of the eye bracket 33 by the clasp 18 for in turn retaining the closure element 17 in engagement with the pin and sleeve socket connector 3. The stop ring 27 is located on the tubular element 19 between the eye bracket 33 and the alignment element 30.

A rear portion 35 of the tubular element 19 extends rearwardly from the eye bracket 33 in order to facilitate holding and gripping the closure element 17 during insertion of the closure element 7 into the pin and sleeve socket connector 3 and removal of the closure element 17 therefrom.

In this embodiment of the invention the tubular element 19 is of plastics material, as is the stop ring 27, the alignment element 30 and the eye bracket 33, and the tubular element 19, the stop ring 27, the alignment element 30 and the eye bracket 33 are integrally formed together in one piece by injection moulding.

Turning now to the clasp 18, the clasp 18 comprises a pair of pivotally connected pincher elements 37 which are pivotally connected together by a pivot pin 38. The pincher elements 37 are of arcuate shape terminating in distal ends 39, and are pivotal about the pivot pin 38 between an open state (not shown) with the distal ends 39 spaced apart from each other, and a closed state with the distal ends 39 overlapping each other. The arcuate shaping of the pincher elements 37 allow the clasp 18 to be operated in the closed state with the pincher elements 37 embracing the hinge 16 which hingedly couples the closure cap 15 to the sleeve 9 of the pin and sleeve socket connector 3, and with the distal ends 39 of the pincher elements 37 extending through the receiving opening 34 of the eye bracket 33 and in overlapping relationship with each other for securing the closure element 17 in engagement with the pin and sleeve socket connector 3 closing the open mouth 11. The arcuate shaping of the pincher elements 37 of the clasp 18 is such that when the pincher elements 37 are in the closed state embracing the hinge 16, the clasp 18 is retained captive on the pin and sleeve socket connector 3 between the closure cap 15 and the housing 6 of the pin and sleeve socket connector 3. A pair of lugs 40 extend from the respective pincher elements 37 on the opposite side of the pivot pin 38 to that from which the pincher elements 37 extend. Each lug 40 is provided with six lock engaging openings 43 which are alignable with each other when the clasp 18 is in the closed state for accommodating a retaining means, namely, a locking element 44 of a padlock 45 for retaining and securing the clasp 18 in the closed state for in turn securing the closure element 17 in the pin and sleeve socket connector 3 closing the open mouth 1 1 thereof.

The clasp 18 is of a metal material, and typically will be of stainless steel or aluminium, and in certain cases, may be of a hardened metal to further enhance the security of the apparatus.

In use, when it is desired to prevent unauthorised access to an electrical pin and sleeve socket connector 3, the closure cap 15 is operated from the closed state to the open state. The closure element 17 is offered up to the open mouth 11 of the pin and sleeve socket connector 3 and is orientated until the alignment element 30 of the tubular element 19 is in alignment with the alignment recess 31 of the pin and sleeve socket connector 3. The forward portion 25 of the tubular element 19 is then urged through the open mouth 1 1 of the sleeve 9 of the pin and sleeve socket connector 3 into the hollow interior region 10 so that the socket block 12 of the pin and sleeve socket connector 3 extends into the hollow interior region 23 of the tubular element 9 through the open mouth 24 thereof and with the forward portion 25 of the tubular element 19 located between the socket block 12 and the sleeve 9. With the alignment element 30 engaging the alignment recess 31 , the eye bracket 33 is appropriately positioned and aligned with the hinge 16 of the closure cap 15 of the pin and sleeve socket connector 3. The clasp 18 with the pincher elements 37 in the open state is then located between the closure cap 15 and the sleeve 9 of the pin and sleeve socket connector 3 adjacent the hinge 16 with the distal ends 39 of the pincher elements 37 aligned with the receiving opening 34 of the eye bracket 33. The pincher elements 37 of the clasp 18 are then urged from the open state to the closed state with the pincher elements 37 embracing the hinge 16, and the distal ends 39 of the pincher elements 37 overlapping and engaged in the receiving opening 34 of the eye bracket 33. In the closed state the lock engaging openings 43 of the lugs 40 are aligned with each other. The locking element 44 of the padlock 45 is then engaged through any one of the aligned pairs of the lock engaging openings 43 of the lugs 40, and the padlock 45 is locked for in turn securely retaining the closure element 17 in engagement with the pin and sleeve socket connector 3 closing the open mouth 11 thereof.

To gain access to the pin and sleeve socket connector 3, the padlock 45 is unlocked and disengaged from the lock engaging openings 43 of the lugs 40 of the clasp 18. The pincher elements 37 of the clasp 18 are then operated into the open state, disengaging the receiving opening 34 of the eye bracket 33 and thereby permitting disengagement of the closure element 17 from the pin and sleeve socket connector 3.

Referring now to Figs. 7 and 8, there is illustrated a pin and sleeve plug connector also according to the invention, indicated generally by the reference numeral 50, for engagement with a pin and sleeve socket connector 3 to form an assembly also according to the invention and indicated generally by the reference numeral 56 and illustrated in Fig. 8. The pin and sleeve socket connector 3 is similar to the pin and sleeve socket connector 3 described with reference to Figs. 1 to 6, and similar components are identified by the same reference numerals. The pin and sleeve plug connector 50 in this embodiment of the invention comprises a closure element 51 which is substantially similar to the closure element 17 described with reference to Figs. 1 to 6, and similar components are identified by the same reference numerals. In this embodiment of the invention a plug block 52 comprising three electrically conductive pins 53 extending therefrom is located in the hollow interior region 23 of the closure element 51. An inwardly extending flange 54 extends inwardly from the tubular element 9 into the hollow interior region 23 for engaging and locating the plug block 52 in the hollow interior region 23. Screws (not shown) secure the plug block 52 to the flange 54. The flange 54 is located relative to the open mouth 24 of the tubular element 19, so that the plug block 52 is spaced apart inwardly from the open mouth 24 with the electrically conductive pins 53 extending from the plug block 52 towards the open mouth 24 of the tubular element 19. The plug block 52 is oriented in the hollow interior region 23 of the tubular element 19, so that when the alignment element 30 is aligned with the alignment recess 31 of the pin and sleeve socket connector 3, the electrically conductive pins 53 are correctly aligned with the appropriate ones of the tubular electrical contact elements 14 of the socket block 12 of the pin and sleeve socket connector 3.

A cable accommodating opening 55 in the end cap 22 of the tubular element 19 accommodates a cable 57 from the plug block 52 for providing an electrical supply from the pin and sleeve plug connector 50 when coupled to the pin and sleeve socket connector 3.

In use, when it is desired to couple the pin and sleeve plug connector 50 to a pin and sleeve socket connector 3, the closure cap 15 of the pin and sleeve socket connector 3 is urged into the open state, and the pin and sleeve plug connector 50 is offered up to the pin and sleeve socket connector 3 with the alignment element 30 aligned with the alignment recess 31 of the pin and sleeve socket connector 3. The pin and sleeve plug connector 50 is engaged in the pin and sleeve socket connector 3 with the electrically conductive pins 53 engaged in the corresponding electrically conductive contact elements 14 of the socket block 12, and with the socket block 12 extending into the hollow interior region 23 of the tubular element 19 through the open mouth 24 thereof, and with the forward portion 25 of the tubular element 17 located between the socket block 12 and the sleeve 9 of the pin and sleeve socket connector 3. The clasp 18 is then operated to secure and retain the pin and sleeve plug connector 50 in engagement with the pin and sleeve socket connector 3 with the distal ends 39 of the pincher elements 37 extending through the receiving opening 34 of the eye bracket 33 and with the pincher elements 37 embracing the hinge 16 of the pin and sleeve socket connector 3. The padlock 45 is engaged in one of the aligned pairs of the lock engaging openings 43 in the lugs 40 of the clasp 18 and locked. Thus the pin and sleeve plug connector 50 is secured in the pin and sleeve socket connector 3 by the clasp 8 and the padlock 45, thereby preventing unauthorised removal of the pin and sleeve plug connector 50 from the pin and sleeve socket connector 3, and in turn unauthorised use of the pin and sleeve socket connector 3.

Referring now to Figs. 9 and 10, there is illustrated a pin and sleeve plug connector also according to the invention, indicated generally by the reference numeral 60, for use with a pin and sleeve socket connector 3, which is similar to the pin and sleeve socket connector 3 described with reference to Figs. 1 to 6. In this embodiment of the invention, the pin and sleeve plug connector 60 comprises a housing 62 comprising a tubular element 63 which is closed at one end by an end cap 64 which defines with the tubular element 63 a hollow interior region 65. The other end of the tubular element 63 terminates in an open mouth 66. A plug block 67 is located in the hollow interior region 65 spaced apart inwardly from the open mouth 66. Three electrically conductive pins 68 extend from the plug block 67 towards the open mouth 66 of the tubular element 63. A cable 69 from the plug block 67 extends through the end cap 64 for providing an electrical supply from the pin and sleeve plug connector 60.

An alignment element 70 extends radially outwardly from a forward portion 71 of the tubular element 63 adjacent the open mouth 66 thereof for aligning the pins 68 of the pin and sleeve plug connector 60 with corresponding contact elements 14 of the pin and sleeve socket connector 3. A stop ring 73 extending circumferentially around and radially outwardly from the tubular element 63 is spaced apart from the open mouth 66 for engaging the sleeve 9 of the pin and sleeve socket connector 3 adjacent the open mouth 11 thereof when the pin and sleeve plug connector 60 is fully engaged in the pin and sleeve socket connector 3. Up to here the pin and sleeve plug connector 60 is similar to a conventional pin and sleeve plug connector and will be well known to those skilled in the art.

A receiver also according to the invention and indicated generally by the reference numeral 72 is secured to the tubular element 63 of the pin and sleeve plug connector 60 for engagement by a clasp similar to the clasp 18 described with reference to Figs. 1 to 6, for in turn securing the pin and sleeve plug connector 60 to a pin and sleeve socket connector similar to the pin and sleeve socket connector 3 in order to prevent unauthorised removal of the pin and sleeve plug connector 60 from the pin and sleeve socket connector 3. The receiver 72 comprises an abutment means, which comprises a base member, namely, an arcuate base plate 74 which is adapted for abutting and engaging an outer surface 75 of the tubular element 63 of the pin and sleeve plug connector 60. An eye bracket 76 substantially similar to the eye bracket 33 of the closure element 15 extends from the base plate 74, so that when the base plate 74 is secured to the tubular element 63 of the pin and sleeve plug connector 60, the eye bracket 76 extends radially outwardly from and axially along the tubular element 63 of the pin and sleeve plug connector 60. The eye bracket 76 defines a receiving opening 78 which is engageable with the pincher elements 37 of the clasp 18 in a similar manner as already described with reference to the assembly 1 of Figs. 1 to 6 for securing the pin and sleeve plug connector 60 in the pin and sleeve socket connector 3. The receiver 60 is of plastics material and is formed by injection moulding.

An attachment means for securely attaching and retaining the receiver 72 on the tubular element 63 comprises a cable tie 79 which extends through a portion 80 of the receiving opening 78 of the eye bracket 76 and which extends around the tubular element 63 of the pin and sleeve plug connector 60 for securely mounting the receiver 72 on the tubular element 63 with the base plate 74 abutting the outer surface 75 of the tubular element 63. When securing the receiver 72 onto the tubular element 63 of the pin and sleeve plug connector 60, the base plate 74 is located on the tubular element 63 with the eye bracket 76 extending radially outwardly from and axially along the tubular element 63 and spaced apart circumferentially around the tubular element 63 an angular distance of approximately 180° from the alignment element 70 so that the eye bracket 76 is substantially aligned with the hinge 16 of the closure cap 15 of the pin and sleeve socket connector 3 when the alignment element 70 is engaged in the alignment recess 31 of the pin and sleeve socket connector 3.

Once the receiver 72 has been secured to the tubular element 63 of the pin and sleeve plug connector 60 by the cable tie 79, engagement of the pin and sleeve plug connector 60 with the pin and sleeve socket connector 3 and securing of the pin and sleeve plug element 60 to the pin and sleeve socket connector 3 by the clasp 18 and the padlock 45 is similar to that described with reference to Figs. 1 to 6 and Figs. 7 and 8. Additionally, while the receiver 72 has been described as comprising an arcuate base plate, the base plate could be planar and of a flexible material so that it could be shaped to take up the arcuate profile of the outer surface of the housing of the pin and sleeve plug connector;

While the attachment means for attaching the receiver to the tubular element 63 of the pin and sleeve plug connector 60 has been described as comprising a cable tie, any other suitable attachment means for securely attaching and retaining the receiver 72 on the tubular element 63 of the pin and sleeve plug connector 60 may be used. For example, it is envisaged that the attachment means may comprise an adhesive which would be used to bond the base plate 74 of the receiver 72 to the tubular element 63. The receiver may be provided with the base plate 74 pre-coated with a suitable adhesive, which could be protected by a "peel-off protective sheet. Needless to say, any other suitable attachment means may be provided. Indeed, it is envisaged that in certain cases the base plate may be constructed to extend completely around the tubular element of the pin and sleeve plug connector 60, and in certain cases, where the base plate is adapted to extend completely around the tubular element of the pin and sleeve plug connector 60, the base plate may be split intermediate its ends and a suitable securing device would be provided for securing the ends of the base plate together for in turn securely attaching and retaining the receiver on the tubular element 63 of the pin and sleeve plug connector 60.

While the closure elements of the apparatus which are described with reference to Figs. 1 to 6 and Figs. 7 and 8 have been described as comprising a tubular element of circular transverse cross-section, any other suitable closure element may be provided of any suitable transverse cross-section. It is also envisaged that the closure element may be constructed of a material other than plastics material, for example, metal or the like.

While the securing means has been described as comprising a clasp, any other suitable securing means for securing the closure element and the pin and sleeve plug connector 60 to the pin and sleeve socket connector may be used.

Furthermore, any other suitable retaining means besides a padlock may be used for retaining and securing the securing means in a closed state.

Claims

1. Apparatus for preventing unauthorised access to an electrical pin and sleeve socket connector of the type comprising a socket block and a sleeve extending around the socket block and spaced apart therefrom, the apparatus comprising a closure element, the closure element comprising an elongated tubular element extending between a first end and a second end and defining a hollow interior region, the first end defining an open mouth to the hollow interior region, the tubular element being configured to be engageable in the pin and sleeve socket connector with the socket block extending through the open mouth of the tubular element into the hollow interior region thereof and with the tubular element engaged between the socket block and the sleeve of the pin and sleeve socket connector, and a receiver extending outwardly from the tubular member, the receiver being configured to receive a releasable securing means with the securing means releasably retaining the closure element in engagement with the pin and sleeve socket connector.

2. Apparatus as claimed in Claim 1 in which the second end of the tubular element is closed by an end cap.

3. Apparatus as claimed in Claim 1 or 2 in which the hollow interior region of the tubular element is configured to house a pin block of an electrical pin and sleeve plug connector.

4. Apparatus as claimed in Claim 3 in which a pin block of a pin and sleeve plug connector is located in the hollow interior region of the tubular element and is configured to electrically engage the socket block of the pin and sleeve socket connector when the tubular element is engaged in the pin and sleeve socket connector.

5. Apparatus as claimed in Claims 3 or 4 in which a cable accommodating opening is provided in the tubular element for accommodating an electrical cable from the pin block of the pin and sleeve plug connector.

6. Apparatus as claimed in Claim 5 in which the cable accommodating opening is located adjacent the second end of the tubular element.

7. Apparatus as claimed in Claim 5 or 6 in which the second end of the tubular element defines the cable accommodating opening.

8. Apparatus as claimed in any preceding claim in which the receiver comprises an eye bracket defining a receiving opening for receiving the securing means.

9. Apparatus as claimed in any preceding claim in which the receiver extends radially from the tubular element.

10. Apparatus as claimed in any preceding claim in which the receiver is non- removably mounted on the tubular element. 11. Apparatus as claimed in any preceding claim in which the receiver is mounted fast on the tubular element.

12. Apparatus as claimed in any preceding claim in which the receiver is integrally formed with the tubular element.

13. Apparatus as claimed in any preceding claim in which the receiver is spaced apart from the first end of the tubular element.

14. Apparatus as claimed in any preceding claim in which the receiver is located on the tubular element intermediate the first and second ends thereof.

15. Apparatus as claimed in any preceding claim in which a portion of the tubular element extending from the receiver to the second end of the tubular element is configured for holding and gripping the closure element during insertion thereof into and removal thereof from the pin and sleeve socket connector.

16. Apparatus as claimed in any preceding claim in which an alignment element is located on the tubular element and is configured to engage a complementary alignment element of the pin and sleeve socket connector for aligning the closure element with the pin and sleeve socket connector.

17. Apparatus as claimed in Claim 16 in which the alignment element is located on the tubular element adjacent the first end thereof extending outwardly from the tubular element. 8. Apparatus as claimed in Claim 16 or 17 in which the alignment element extends radially outwardly from the tubular element.

19. Apparatus as claimed in any of Claims 16 to 18 in which the alignment, element is axially spaced apart from the receiver.

20. Apparatus as claimed in any of Claims 16 to 19 in which the alignment element is circumferentially spaced apart from the receiver.

21. Apparatus as claimed in Claim 20 in which the alignment element is circumferentially spaced apart from the receiver at an angle of approximately 180°.

22. Apparatus as claimed in any preceding claim in which a stop member is located on the tubular element for engaging the pin and sleeve socket connector with the tubular element engaged in the pin and sleeve socket connector with the socket block located within the hollow interior region of the tubular element and with the tubular element located between the socket block and the sleeve of the pin and sleeve socket connector.

23. Apparatus as claimed in Claim 22 in which the stop member is located intermediate the receiver and the first end of the tubular element. 24. Apparatus as claimed in Claim 22 or 23 in which the stop member extends outwardly of the tubular element.

25. Apparatus as claimed in any of Claims 22 to 24 in which the stop member extends radially outwardly from the tubular element.

26. Apparatus as claimed in any of Claims 22 to 25 in which the stop member extends circumferentially around the tubular element.

27. Apparatus as claimed in any preceding claim in which the tubular element is of circular transverse cross-section.

28. Apparatus as claimed in any preceding claim in which the tubular element comprises one of a plastics material and a metal material.

29. Apparatus as claimed in any preceding claim in which the receiver comprises one of a plastics material and a metal material. 30. Apparatus as claimed in any preceding claim in which the alignment element comprises one of a plastics material and a metal material, and is integrally formed with the tubular element.

31. Apparatus as claimed in any preceding claim in which the stop member comprises one of a plastics material and a metal material, and is formed integrally with the tubular element.

32. Apparatus as claimed in any preceding claim further comprising the securing means.

33. Apparatus as claimed in Claim 32 in which the securing means comprises a clasp operable between an open state and a closed state, and being configured in the closed state for engagement by a retaining means for retaining the securing means in the closed state.

34. Apparatus as claimed in Claim 33 in which the clasp comprises a pair of pivotally connected pincher elements terminating in respective distal ends, the pincher elements being pivotal between the open state and the closed state, and being configured to embrace a portion of the pin and sleeve socket connector in the closed state for releasably engaging the pin and sleeve socket connector with at least one of the pincher elements engaged in the receiver for preventing removal of the closure element from the pin and sleeve socket connector.

35. Apparatus as claimed in Claim 34 in which the pincher elements are configured so that each pincher element engages the receiver in the closed state.

36. Apparatus as claimed in Claim 34 or 35 in which the pincher elements are configured to embrace a hinge of the pin and sleeve socket connector which hingedly couples a closure cap to the pin and sleeve socket connector for preventing access to the pin and sleeve socket connector.

37. Apparatus as claimed in Claim 36 in which the pincher elements are configured to embrace the hinge of the pin and sleeve socket connector when the closure cap is in an open state with the pincher elements located between the closure cap and the pin and sleeve socket connector.

38. Apparatus as claimed in any of Claims 34 to 37 in which the pincher elements are of arcuate shape.

39. Apparatus as claimed in any of Claims 34 to 38 in which a pair of lugs extend from the respective pincher elements, the lugs being configured for engagement by the retaining means with the pincher elements in the closed state.

40. Apparatus as claimed in Claim 39 in which each lug comprises a lock engaging opening, the lock engaging openings of the respective lugs being aligned when the pincher elements are in the closed state for engaging the retaining means for retaining the pincher elements in the closed state.

41. Apparatus as claimed in Claim 39 or 40 in which the lugs extend from the pivotal connection connecting the pincher elements on the opposite side of the pivot connection from the side of the pivot connection from which the pincher elements extend.

42. Apparatus as claimed in any of Claims 33 to 41 further comprising the retaining means engageable with the securing means.

43. Apparatus as claimed in Claim 42 in which the retaining means comprises a padlock.

44. An assembly comprising an electrical pin and sleeve socket connector, the pin and sleeve socket connector comprising a socket block, and a sleeve extending around the socket block and spaced apart therefrom, and the apparatus as claimed in any preceding claim with the tubular element of the closure element thereof engaged in the pin and sleeve socket connector, with the socket block of the pin and sleeve socket connector extending into the hollow interior region of the tubular element, and with the tubular element located between the socket block and the sleeve of the pin and sleeve socket connector.

45. An assembly comprising an electrical pin and sleeve socket connector, the pin and sleeve socket connector comprising a socket block, and a sleeve extending around the socket block and spaced apart therefrom, and apparatus for preventing unauthorised access to the pin and sleeve socket connector, the apparatus comprising a closure element, the closure element comprising an elongated tubular element extending between a first end and a second end and defining a hollow interior region, the first end defining an open mouth to the hollow interior region, the tubular element being engaged in the pin and sleeve socket connector with the socket block extending through the open mouth of the tubular element into the hollow interior region thereof, and with the tubular element engaged between the socket block and the sleeve, a receiver extending outwardly from the tubular member, and a securing means releasably engaged with the receiver and with a portion of the pin and sleeve socket connector for releasably retaining the closure element in engagement with the pin and sleeve socket connector.

46. An assembly as claimed in Claim 45 in which the second end of the tubular element is closed by an end cap.

47. An assembly as claimed in Claim 45 or 46 in which the hollow interior region of the tubular element is configured to house a pin block of a pin and sleeve plug connector.

48. An assembly as claimed in Claim 47 in which a pin block of a pin and sleeve plug connector is located in the hollow interior region of the tubular element and is electrically engaged in the socket block of the pin and sleeve socket connector.

49. An assembly as claimed in Claims 47 or 48 in which a cable accommodating opening is provided in the tubular element, and an electrical cable extending from the pin block of the pin and sleeve plug connector extends through the cable accommodating opening.

50. An assembly as claimed in Claim 49 in which the cable accommodating opening is located adjacent the second end of the tubular element.

51 . An assembly as claimed in Claim 49 or 50 in which the second end of the tubular element defines the cable accommodating opening.

52. An assembly as claimed in any of Claims 45 to 51 in which the receiver comprises an eye bracket defining a receiving opening and the securing means is engaged in the receiving opening.

53. An assembly as claimed in any of Claims 45 to 52 in which the receiver extends radially from the tubular element.

54. An assembly as claimed in any of Claims 45 to 53 in which the receiver is non-removably mounted on the tubular element.

55. An assembly as claimed in any of Claims 45 to 54 in which the receiver is mounted fast on the tubular element.

56. An assembly as claimed in any of Claims 45 to 55 in which the receiver is integrally formed with the tubular element. 57. An assembly as claimed in any of Claims 45 to 56 in which the receiver is spaced apart from the first end of the tubular element.

58. An assembly as claimed in any of Claims 45 to 57 in which the receiver is located on the tubular element intermediate the first and second ends thereof.

59. An assembly as claimed in any of Claims 45 to 58 in which a portion of the tubular element extending from the receiver to the second end of the tubular element is configured for holding and gripping the closure element during insertion thereof into and removal thereof from the pin and sleeve socket connector.

60. An assembly as claimed in any of Claims 45 to 59 in which an alignment element is located on the tubular element and is engaged in a complementary alignment element of the pin and sleeve socket connector for aligning the closure element with the pin and sleeve socket connector.

61 . An assembly as claimed in Claim 60 in which the alignment element is located on the tubular element adjacent the first end thereof extending outwardly from the tubular element. 62. An assembly as claimed in Claim 60 or 61 in which the alignment element extends radially outwardly from the tubular element.

63. An assembly as claimed in any of Claims 60 to 62 in which the alignment element is axially spaced apart from the receiver.

64. An assembly as claimed in any of Claims 60 to 63 in which the alignment element is circumferentially spaced apart from the receiver.

65. An assembly as claimed in Claim 64 in which the alignment element is circumferentially spaced apart from the receiver at an angle of approximately 180°.

66. An assembly as claimed in any of Claims 45 to 65 in which a stop member is located on the tubular element, the stop member engaging the pin and sleeve socket connector.

67. An assembly as claimed in Claim 66 in which the stop member is located intermediate the receiver and the first end of the tubular element.

68. An assembly as claimed in Claim 66 or 67 in which the stop member extends outwardly of the tubular element.

69. An assembly as claimed in any of Claims 66 to 68 in which the stop member extends radially outwardly from the tubular element.

70. An assembly as claimed in any of Claims 66 to 69 in which the stop member extends circumferentially around the tubular element. 71. An assembly as claimed in any of Claims 45 to 70 in which the tubular element is of circular transverse cross-section.

72. An assembly as claimed in any of Claims 45 to 71 in which the tubular element comprises one of a plastics material and a metal material.

73. An assembly as claimed in any of Claims 45 to 72 in which the receiver comprises one of a plastics material and a metal material.

74. An assembly as claimed in any of Claims 45 to 73 in which the alignment element comprises one of a plastics material and a metal material, and is integrally formed with the tubular element.

75. An assembly as claimed in any of Claims 45 to 74 in which the stop member comprises one of a plastics material and a metal material, and is formed integrally with the tubular element.

76. An assembly as claimed in any of Claims 45 to 75 in which the securing means comprises a clasp operable between an open state and a closed state, and being configured in the closed state for engaging a retaining means for retaining the securing means in the closed state.

77. An assembly as claimed in Claim 76 in which the clasp comprises a pair of pivotally connected pincher elements terminating in respective distal ends, the pincher elements being pivotal between the open state and the closed state, and embracing a portion of the pin and sleeve socket connector in the closed state for releasably engaging the pin and sleeve socket connector, and at least one of the pincher elements engaged in the receiver for preventing removal of the closure element from the pin and sleeve socket connector.

78. An assembly as claimed in Claim 77 in which the receiver is engaged by both of the pincher elements of the clasp in the closed state. 79. An assembly as claimed in Claim 77 or 78 in which the pin and sleeve socket connector comprises a closure cap for preventing access to the pin and sleeve socket connector, the closure cap being hingedly coupled to the pin and sleeve socket connector by a hinge, and the pincher elements of the clasp embrace the hinge of the pin and sleeve socket connector.

80. An assembly as claimed in Claim 79 in which the pincher elements of the clasp embrace the hinge of the pin and sleeve socket connector when the closure cap is in an open state with the pincher elements of the clasp located between the closure cap and the pin and sleeve socket connector.

81. An assembly as claimed in any of Claims 77 to 80 in which the pincher elements are of arcuate shape.

82. An assembly as claimed in any of Claims 77 to 81 in which a pair of lugs extend from the respective pincher elements of the clasp, the lugs being configured for engagement b the retaining means with the pincher elements in the closed state.

83. An assembly as claimed in Claim 82 in which each lug comprises a lock engaging opening, the lock engaging openings of the respective lugs being aligned when the pincher elements are in the closed state for engaging the retaining means for retaining the pincher elements in the closed state.

84. An assembly as claimed in Claim 82 or 83 in which the lugs extend from the pivotal connection connecting the pincher elements on the opposite side of the pivot connection from the side of the pivot connection from which the pincher elements extend.

85. An assembly as claimed in any of Claims 82 to 84 further comprising the retaining means engaged in the lock engaging openings of the lugs of the securing means. 86. An assembly as claimed in Claim 85 in which the retaining means comprises a padlock.

87. A method for preventing unauthorised access to an electrical pin and sleeve socket connector of the type comprising a socket block and a sleeve extending around the socket block and spaced apart therefrom, the method comprising releasably securing a closure element in the pin and sleeve socket connector, the closure element comprising an elongated tubular element extending between a first end and a second end and defining a hollow interior region, the first end defining an open mouth to the hollow interior region, engaging the tubular element in the pin and sleeve socket connector with the socket block extending through the open mouth of the tubular element into the hollow interior region thereof and with the tubular element engaged between the socket block and the sleeve, and releasably securing the closure element in the pin and sleeve socket connector by a securing means releasably engageable with a portion of the pin and sleeve socket connector and with a receiver extending outwardly from the tubular member.

88. A method as claimed in Claim 87 in which the second end of the tubular element is closed by an end cap.

89. A method as claimed in Claims 87 or 88 in which the hollow interior region of the tubular element is configured to house a pin block of a pin and sleeve plug connector.

90. A method as claimed in Claim 89 in which a pin block of a pin and sleeve plug connector is located in the hollow interior region of the tubular element, and the method further comprises electrically engaging the pin block with the socket block of the pin and sleeve socket connector when the tubular element is being engaged in the pin and sleeve socket connector.

91. A method as claimed in any of Claims 87 to 90 in which the receiver comprises an eye bracket defining a receiving opening for receiving the securing means.

92. A method as claimed in any of Claims 87 to 91 in which the receiver extends radially from the tubular element.

93. A method as claimed in any of Claims 87 to 92 in which the receiver is non- removably mounted on the tubular element.

94. A method as claimed in any of Claims 87 to 93 in which the receiver is mounted fast on the tubular element. 95. A method as claimed in any of Claims 87 to 94 in which the receiver is integrally formed with the tubular element.

96. A method as claimed in any of Claims 87 to 95 in which the receiver is spaced apart from the first end of the tubular element.

97. A method as claimed in any of Claims 87 to 96 in which the receiver is located on the tubular element intermediate the first and second ends thereof.

98. A method as claimed in any of Claims 87 to 97 in which a portion of the tubular element extending from the receiver to the second end of the tubular element is configured for holding and gripping the closure element during insertion thereof into and removal thereof from the pin and sleeve socket connector.

99. A method as claimed in any of Claims 87 to 98 in which an alignment element is located on the tubular element and is configured to engage a

complementary alignment element of the pin and sleeve socket connector for aligning the closure element with the pin and sleeve socket connector.

100. A method as claimed in Claim 99 in which the alignment element is located on the tubular element adjacent the first end thereof extending outwardly from the tubular element. 101. A method as claimed in any of Claims 87 to 100 in which a stop member is located on the tubular element for engaging the pin and sleeve socket connector with the tubular element engaged in the pin and sleeve socket connector with the socket block located within the hollow interior region of the tubular element and with the tubular element located between the sleeve and the socket block of the pin and sleeve socket connector.

102. A method as claimed in any of Claims 87 to 101 in which the tubular element is of circular transverse cross-section. 103. A method as claimed in any of Claims 87 to 102 in which the securing means comprises a clasp operable between an open state and a closed state, and being configured in the closed state for engaging a retaining means for retaining the securing means in the closed state.

104. A method as claimed in Claim 103 in which the clasp comprises a pair of pivotally connected pincher elements terminating in respective distal ends, the pincher elements being pivotal between the open state and the closed state, and being configured to embrace a portion of the pin and sleeve socket connector in the closed state with at least one of the pincher elements engaged in the receiver for preventing removal of the closure element from the pin and sleeve socket connector.

105. A method as claimed in Claim 104 in which the pincher elements embrace a hinge of the pin and sleeve socket connector which hingedly couples a closure cap to the pin and sleeve socket connector for preventing access to the pin and sleeve socket connector.

106. A method as claimed in Claim 05 in which the pincher elements embrace the hinge of the pin and sleeve socket connector when the closure cap is in an open state with the pincher elements located between the closure cap and the pin and sleeve socket connector. 07. A method as claimed in any of Claims 104 to 106 in which the pincher elements are of arcuate shape.

108. A method as claimed in any of Claims 104 to 107 in which a pair of lugs extend from the respective pincher elements, the lugs being configured to engage the retaining means with the pincher elements in the closed state. 09. A method as claimed in Claim 108 in which each lug comprises a lock engaging opening, the lock engaging openings of the respective lugs being aligned when the closure elements are in the closed state for engaging the retaining means for retaining the pincher elements in the closed state. 10. A method as claimed in any of Claims 103 to 109 in which the method further comprises engaging the securing means with the receiver and with the pin and sleeve socket connector, and engaging the retaining means with the securing means.

111. A method as claimed in Claim 110 in which the retaining means comprises a padlock.

112. An electrical pin and sleeve plug connector comprising a housing, and a receiver extending from an outer surface of the housing for receiving a releasable securing means to secure and releasably retain the pin and sleeve plug connector in engagement with a pin and sleeve socket connector. 13. An electrical pin and sleeve plug connector as claimed in Claim 1 12 in which the receiver comprises an eye bracket defining a receiving opening for receiving the securing means. 114. An electrical pin and sleeve plug connector as claimed in Claim 1 13 in which the eye bracket extends radially from the housing of the pin and sleeve plug connector.

115. An electrical pin and sleeve plug connector as claimed in any of Claims 112 to 114 in which the receiver is substantially non-removably mounted on the housing.

116. An electrical pin and sleeve plug connector as claimed in any of Claims 12 to 115 in which the receiver is mounted fast on the housing. 117. An electrical pin and sleeve plug connector as claimed in any of Claims 112 to 116 in which the receiver is located on the housing intermediate respective first and second ends thereof.

118. An electrical pin and sleeve plug connector as claimed in any of Claims 112 to 117 in which the receiver is integrally formed with the housing.

1 19. An electrical pin and sleeve plug connector as claimed in any of Claims 2 to 117 in which the receiver comprises an abutment means for abutting the housing.

120. An electrical pin and sleeve plug connector as claimed in Claim 1 19 in which the abutment means of the receiver comprises a base member configured to engage the outer surface of the housing.

121. An electrical pin and sleeve plug connector as claimed in Claim 1 19 or 120 in which the eye bracket extends substantially perpendicularly from the base member.

122. An electrical pin and sleeve plug connector as claimed in any of Claims 1 19 to 121 further comprising an attachment means for securing the base member to the housing.

123. An electrical pin and sleeve plug connector as claimed in Claim 122 in which the attachment means comprises an elongated ligature for securing the base member to the housing.

124. An electrical pin and sleeve plug connector as claimed in Claim 122 or 123 in which the receiver defines a ligature accommodating opening for accommodating the ligature of the attachment means extending therethrough with the ligature extending around the housing for securing the base member to the housing.

125. An electrical pin and sleeve plug connector as claimed in any of Claims 122 to 124 in which the ligature comprises a cable tie. 126. An assembly comprising an electrical pin and sleeve plug connector as claimed in any of Claims 1 12 to 123 releasably secured to a pin and sleeve socket connector by a securing means.

127. An assembly as claimed in Claim 126 in which the securing means comprises a clasp operable between an open state and a closed state, and being configured in the closed state for engaging a retaining means for retaining the securing means in the closed state.

128. An assembly as claimed in Claim 126 or 127 in which the securing means comprises a pair of pivotally connected pincher elements terminating in respective distal ends, the pincher elements being pivotal between the open state and the closed state, and being configured to embrace a portion of the pin and sleeve socket connector in the closed state with at least one of the pincher elements engaged in the receiver for preventing removal of the pin and sleeve plug connector from the pin and sleeve socket connector. 29. An assembly as claimed in Claim 128 in which the pincher elements are configured to embrace a hinge of the pin and sleeve socket connector which hingedly couples a closure cap to the pin and sleeve socket connector for preventing access to the pin and sleeve socket connector.

130. An assembly as claimed in Claim 128 or 129 in which the pincher elements are configured to embrace the hinge of the pin and sleeve socket connector when the closure cap is in an open state with the pincher elements located between the closure cap and the pin and sleeve socket connector.

131. An assembly as claimed in Claims 128 to 130 in which the pincher elements are of arcuate shape.

132. An assembly as claimed in any of Claims 128 to 131 in which a pair of lugs extend from the respective pincher elements, the lugs being configured to engage a retaining means with the pincher elements in the closed state.

133. An assembly as claimed in Claim 132 in which each lug comprises a lock engaging opening, the lock engaging openings of the respective lugs being aligned when the pincher elements are in the closed state for engaging the retaining means for retaining the pincher elements in the closed state.

134. An assembly as claimed in Claim 132 or 133 in which the lugs extend from the pivotal connection between the pincher elements on the opposite side of the pivot connection from the side of the pivot connection from which the pincher elements extend.

135. An assembly as claimed in any of Claims 132 to 134 further comprising the retaining means engaged with the securing means.

136. An assembly as claimed in Claim 135 in which the retaining means comprises a padlock.

137. A receiver for attaching to a housing of a pin and sleeve plug connector, the receiver being configured to be engageable by a securing means for securing the pin and sleeve plug connector to a pin and sleeve socket connector, and comprising an abutment means for abutting a housing of the pin and sleeve plug connector, and an eye bracket extending from the abutment means and defining a receiving opening therethrough for engagement by the securing means.

138. A receiver as claimed in Claim 137 in which the abutment means comprises a base member.

139. A .receiver as claimed in Claim 137 or 138 further comprising an attachment means for securing the abutment means to the housing of the pin and sleeve plug connector.

140. A receiver as claimed in any of Claims 137 to 139 in which the attachment means comprises an elongated ligature configured to extend around the housing of the pin and sleeve plug connector.

141. A method for adapting a pin and sleeve plug connector for securing to a pin and sleeve socket connector by a securing means, the method comprising attaching the receiver as claimed in any of Claims 137 to 140 to a housing of the pin and sleeve plug connector by the attachment means. 1/5

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30 14c

Fig.4 3/5

Fig.6 4/5

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