EP2232648A1

EP2232648A1 - Electrical connector

Info

Publication number: EP2232648A1
Application number: EP08875675A
Authority: EP
Inventors: Scott Horner; Geof Hunter
Original assignee: Wlucy&co Ltd
Current assignee: Wlucy&co Ltd
Priority date: 2007-12-22
Filing date: 2008-12-22
Publication date: 2010-09-29
Also published as: GB0725129D0; GB2455808B; WO2010072987A1; GB2455808A

Abstract

An electrical cut-out comprises (in its first aspect) a base unit and a removable link unit, the base unit including at least two contacts each having a cable termination, the link unit being seatable on the base and including a conductor arranged to bridge the at least two contacts when the link unit is so seated, wherein the base unit and the link unit each comprise an eye for receiving a tamper-evident seal, at least one of the two eyes being defined by a first and second limbs projecting from a side face of the base unit and/or the link unit at spaced locations, the first limb having a substantially planar upper face and the second limb having a substantially planar lower face that is not below the substantially planar upper face of the first limb, the first and second limbs being joined at a location spaced from the side face thereby to define an eye. Thus, an eye to provide for the necessary security tag can be provided as part of an injection moulding arrangement with no re-entrant parts and no post-moulding fabrication steps. A modern injection mould employing one or more sliding members can create such a shape and permit its removal from the mould.

Description

Electrical Connector

FIELD OF THE INVENTION

The present invention relates to an electrical connector.

BACKGROUND ART

Electrical connectors are required for a wide range of contexts, and generally their design varies according to their intended purpose. The constraints of space, environment, access, and the necessary electrical functionality and rating mean that each context calls for a different design.

One such context is the so-called "House Service Cut-Out" (HSCO). This is a unit housing a removable link at the demarcation point between a utility and a customer, just before a meter. As the name suggests, it is primarily applied to domestic customers but could also be used for small commercial customers. Its purpose is to provide a break point in the supply that can be removed in order to completely isolate the live connection if required. A fuse is sometimes incorporated in the removable link.

To achieve the necessary electrical functionality, an HSCO is usually provided with a base unit having cable terminations to each of a pair of contacts, one for the incoming supply and one for the outgoing supply. The removable link will then be seatable on or in the base unit and will contain one or more conductors which, when the removable link is seated on or in the base unit, make contact with and bridge the pair of contacts. Thus, then the removable link is in place, the customer's meter is made live but removal of the link cuts all power to the customer.

An HSCO must be secure against tampering, since if not then access could be gained to the electrical supply ahead of the meter. This would facilitate theft of the electricity. Thus, a tag point is usually provided in order to accept a tamper-evident seal.

SUMMARY OF THE INVENTION

In its first aspect, the present invention therefore provides an electrical cut-out comprising a base unit and a removable link unit, the base unit including at least two contacts each having a cable termination, the link unit being seatable on the base and including a conductor arranged to bridge the at least two contacts when the link unit is so seated, wherein the base unit and the link unit each comprise an eye for receiving a tamper-evident seal, at least one of the two eyes being defined by a first and second limbs projecting from a side face of the base unit and/or the link unit at spaced locations, the first limb having a substantially planar upper face and the second limb having a substantially planar lower face that is not below the substantially planar upper face of the first limb, the first and second limbs being joined at a location spaced from the side face thereby to define an eye.

Thus, an eye to provide for the necessary security tag can be provided as part of an injection moulding arrangement with no re-entrant parts and no post- moulding fabrication steps. A modern injection mould employing one or more sliding members can create such a shape and permit its removal from the mould.

In a second aspect, the present invention provides an electrical cut-out comprising a base unit and a removable link unit, the base unit having a housing including at least three contacts each having a cable termination, the housing comprising an aperture adjacent each contact and an opening for the removable link unit, the link unit being seatable on the base unit thereby to cover the opening and including a conductor arranged to bridge at least two of the contacts when the link unit is so seated, the base unit including at least one blanking element disposed so as to block one of the apertures; the blanking element being accessible for removal via the opening.

Thus, any unused contacts can be covered so as to prevent access, both for safety reasons and to prevent theft of electricity.

The blanking element is preferably disposed within the aperture, thereby to block it. This allows the blanking element to be expelled via the aperture, through an outward force exerted on the rear of the blanking element accessed via the opening.

The base unit preferably includes an internal wall, which at least partially covers the contacts and has an access space positioned so that an elongate object extending through the space to the blanking element lies generally transverse to the aperture. This allows a suitable object such as a screwdriver to be inserted and used to lever the blanking element out.

We also prefer that the outermost extremity of the blanking element is recessed relative to the outermost extent of the aperture, thereby to inhibit extraction of the blanking element via the aperture. This will make it more difficult for unauthorised persons to remove the blanking element and gain access to the live and unmetered contacts. The outermost face of the blanking element can be made substantially smooth to reduce the prospect of gaining any purchase on the blanking element in order to remove it. The blanking element can also comprise an outwardly extending lip for engagement with the base unit, thereby to inhibit removal.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the present invention will now be described by way of example, with reference to the accompanying figures in which; Figure 1 shows in schematic form the location of the electrical cut-out of the present invention in a typical home or small commercial electrical supply;

Figure 2 shows a perspective view of the cut-out;

Figure 3 shows the security eye from above;

Figure 4 shows the security eye from the side;

Figure 5 shows the security eye from beneath;

Figure 6 shows the electrical cut-out in disassembled form; and

Figure 7 shows a vertical section through the electrical cut-out.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Figure 1 shows, in schematic form, the general context in which the electrical cut out of the present invention is located. An electrical supply conduit 10 will deliver live 12 and neutral 14 conductors to an electrical junction box 16 at the edge of domestic or small commercial establishment 18. Within the junction box 16 there will be an electrical meter 20 which measures the total electrical consumption of the unit 18. It is necessary to provide an electrical cut out ahead of the meter 20, so that the supply can be disconnected and to provide a demarcation point between the local electricity supply company and the customer, and this is achieved by way of a cut out generally designated as 22.

The electrical cut-out 22 comprises an incoming electrical bus 24 and an outgoing electrical bus 26 that each have a plurality of contacts. In this embodiment, two contacts 24a, 24b and 26a, 26b are provided on each electrical bus. The two buses are bridged by a linking piece 28 that is removable. Thus, in a default arrangement the incoming live cable 12 is connected to one of the contacts 24a of the incoming electrical bus 24 and a live connection is made to the outgoing electrical bus 26 on one of the contacts 26a. That outgoing live cable then leads to the electrical meter 20. When a supply connection is to be made, the linking piece 28 is fitted which provides an electrical conduction path between the two buses 24, 26 and thereby connects the unit 18 to the electrical power supply.

A plurality of incoming and outgoing contacts are provided on each of the buses 24, 26 so that there is a degree of redundancy to allow for future breakage or damage, and also to allow for the possibility that more than one outgoing connection may need to be made. The possibility also remains to allow for redundant incoming cabling. However, this introduces the potential difficulty that there are a plurality of spare live electrical contacts available upstream of the meter 20. If the customer chooses to make an electrical connection to one or more of these, they can effectively obtain free electricity. Whilst this is a criminal offence in most jurisdictions and can be dealt with accordingly if detected, it would in principle be more convenient to prevent it happening in the first place.

One way in which this can be done is to prevent removal of the linking piece 28 other than by authorised service personnel. Another is to limit access to the contacts 26a, 26b and 24a, 24b. Both of these measures are adopted in embodiments of the present invention, as will become apparent from the following description.

Figure 2 shows a perspective view of an electrical cut-out according to the present invention. The cut-out 22 generally comprises a base unit 30 consisting of a lower base section 32 and an upper base section 34, and a removable link unit 36 which is insertable into the upper base unit 34. The lower base unit 32 contains electrical contacts, bus bars and conductors according to the above schematic description and has a pair of apertures 38, 40 at one end, duplicated 42, 44 at the other end. The necessary contacts 24a, 24b, 26a, 26b are accessible through the apertures 38, 40, 42, 44. The upper base section 34 is permanently fixed to the lower base section 32 during manufacture and contains an internal wall at its lower extremity, generally covering the contacts. Gaps are provided in the internal wall so as to provide the necessary access, as will be described later. The upper base section 34 is open, thereby allowing insertion of the link unit 36 into the opening 46 that is thus defined in the top of the lower base section 34. The link unit 36 comprises electrical conductors to bridge the two buses within the lower base section 32, as will be described later.

The link unit 36 is removable from the upper base section 34. To prevent undetected unauthorised removal, a pair of eyes 48, 50 are provided at either end of the link unit 36 and the upper base section 34, respectively. These eyes 48, 50 are co-aligned so as to allow a security tag to be threaded between the two eyes, tightened, and secured with a tamper-evident seal. As and when the meter is read, that seal can be checked to be sure that it has not been disturbed. If it has been disturbed, this will indicate that the electrical cut-out has been accessed in an unauthorised manner. Authorised service personnel will of course be able to replace the seal with a fresh example.

It is relatively straight forward to mould the eye 50 on the upper base unit 34, in this example, since this lies on an extremity of the device and can therefore be moulded using a suitable moveable core that provides an aperture in the middle of the eye 50. However, the eye 48 on the link unit 36 presents a little more difficulty in that it is not at one extremity of the device; there are further parts of the link unit 36 which extend into the opening 46 in order to locate the link unit 36 in place and secure it against lateral movement, as can be seen in figure 6. This means that moulding such an eye is somewhat more problematic.

Figures 3, 4 and 5 show the design of eye that is adopted in order to overcome this. A pair of limbs 52, 54 project from the side of the link unit 36, one slightly above the other. Each is generally rectangular in cross section as can be seen in figure 4, and each contributes towards a portion to the overall shape of the eye as can be seen in figures 3 and 5. The uppermost limb of the two 52 extends outwardly and has a curved outer edge 56 to define the eye shape, but ends at a vertical face 58 approximately half way around the loop of the eye 48. Meanwhile, the lower limb 54 has an upper face 60 generally aligned with the lower face 62 of the upper eye 56 and therefore fits underneath the upper limb 52. It continues past the end face 58, beneath the upper limb 52, and has its own lower end face 64 which is generally parallel to the side face 66 of the link unit 36.

The upper and lower limbs 52, 54 overlap so that, together, they define an eye in that a hole region 68 is enclosed on all sides by a combination of the side face 66, the upper limb 52 and the lower limb 54. However, the design allows two sliding parts within a moulding tool to define the upper and lower limbs 52, 54 without the need for any more complex mould parts such as a central mandrel.

Figure 6 shows the cut-out 22 in exploded form. The lower base unit 32 includes the four apertures 38, 40, 42, behind each of which are located one of four contacts 24b, 26b within an interior space of the lower base unit 32. These employ generally conventional screw-threaded cable clamps so as to make a secure electrical connection with the conductor of a cable inserted via the associated aperture.

The interior space of the lower base unit 32 is closed by the upper base unit 34. This comprises a cover section 70 at its lower extremity which closes the lower base unit 32 to prevent unintended access, and which includes the necessary access ports to permit necessary access, such as to remove blanking plates (as will be described later) and to permit access for conductors to the contacts 24a, 24b, 26a, 26b. A rivet 72 holds the upper base unit 34 in place over the lower base unit 32.

A set of four side walls 74, 76, 78, 80 extend upwardly from the cover section 70, to act as a socket for the link unit 36. This has a lower portion 82 sized to fit snugly within the interior region defined by the side walls 74, 76, 78, 80. The two contacts 84, 86 depend downwardly from the lower portion 82 and each include a pair of outwardly biased leaf contacts 88, 90. When the link unit 36 is fitted in place on the upper base unit 34, these extend through openings in the cover section 70 and fit between like pairs of contacts. Thus, the contact 84 fits between the incoming contacts 24a, 24b and the contact 86 fits between the outgoing contacts 26a, 26b. The outward biasing of the leaf contacts means that each makes a conductive electrical connection with the relevant contact.

Within the link unit 36, the contacts 84, 86 are connected via any fuses, overload protectors or the like as are considered necessary for the context in which the device is to be fitted. Thus, when the link unit 36 is in place, an electrical connection is made between the incoming contacts 24a, 24b and the outgoing contacts 26a, 26b.

Fig 7 shows a vertical section through the base unit, showing the apertures 40, 44 leading to the respective contacts 24b, 26b. Each aperture comprises an elongate conduit section 92 formed with a narrowing aspect so that the inner end of the conduit section proximate the contact 24b is narrower than the open end into which cables will be inserted. This assists in guiding cables toward the contact 24b and also assists in hindering removal of a blanking element 94. The blanking element 94 is a correspondingly-shaped plug which rests in the conduit section in front of the contact 24b and prevents access being gained to the contact 24b for illicit use as described above and for safety reasons. The blanking element 94 is somewhat shorter than the conduit section 92 so that its outer extent is still within the conduit section 92. This means that, viewed from the outside, the blanking element 94 is recessed and difficult to gain purchase on. To further assist in this regard, the front face is substantially flat, being completely smooth other than a raised line detail to indicate the orientation of the blanking element 94.

To remove the blanking element 94 and thereby gain access to the contact 24b in order to connect a cable, it is necessary to remove the link unit 36 (thereby removing any seal placed on the eyes 48, 50). This exposes the cover section 70 and a port 96 therein through which the rear face of the blanking element 94 is accessible. This permits an elongate tool such as a screwdriver blade 98 to be inserted behind the blanking element to lever it out be expelling it through the conduit section 92. A lip 100 extends transversely from the blanking element 94 to engage behind the end of the conduit section 92 and resist expulsion; this can be easily overcome via the tool 98 but prevents the blanking plate 94 from falling out.

The blanking element 94 also includes a raised longitudinal ridge 102 which fits within a corresponding slot 104 in the conduit section 92, to orient the blanking plate 94. The correct orientation can be confirmed by inspection of the raised line detail (above). The interaction of the ridge 102 and the slot 104 hinders rotation of the blanking element 94, thereby further resisting removal by hindering any attempt to gain purchase on the element 94 such as might permit unauthorised removal.

A similar arrangement can be provided for each of the apertures 38, 40, 42, 44. As supplied, the cut-out may be provided with four blanking elements, one for each aperture, or it may be provided with only two in the expectation that all such cut-outs will be fitted with at least two cables, one incoming and one outgoing, thereby meaning that at least two apertures will always be used and hence will not require a blanking element.

It will of course be understood that many variations may be made to the above-described embodiment without departing from the scope of the present invention.

Claims

1. An electrical cut-out comprising a base unit and a removable link unit, the base unit including at least two contacts each having a cable termination, the link unit being seatable on the base and including a conductor arranged to bridge the at least two contacts when the link unit is so seated, wherein the base unit and the link unit each comprise an eye for receiving a tamper-evident seal, at least one of the two eyes being defined by a first and second limbs projecting from a side face of the base unit and/or the link unit at spaced locations, the first limb having a substantially planar upper face and the second limb having a substantially planar lower face that is not below the substantially planar upper face of the first limb, the first and second limbs being joined at a location spaced from the side face thereby to define an eye.

2. An electrical cut-out comprising a base unit and a removable link unit, the base unit having a housing including at least three contacts each having a cable termination, the housing comprising an aperture adjacent each contact and an opening for the removable link unit; the link unit being seatable on the base unit thereby to cover the opening, and including a conductor arranged to bridge at least two of the contacts when the link unit is so seated, the base unit including at least one blanking element disposed so as to block one of the apertures; the blanking element being accessible for removal via the opening.

3. An electrical cut-out according to claim 2 in which the blanking element is disposed in the aperture thereby to block it.

4. An electrical cut-out according to claim 3 in which the blanking element is accessible via the opening thereby to expel it via the aperture.

5. An electrical cut-out according to any one of claims 3 to 4 in which the base unit includes an internal wall at least partially covering the contacts and having an access space positioned in the internal wall so that an elongate object extending through the space to the blanking element lies generally transverse to the aperture thereby to expel the blanking element by a lever action.

6. An electrical cut-out according to any one of claims 3 to 5 in which the outermost extremity of the blanking element is recessed relative to the outermost extent of the aperture thereby to inhibit extraction of the blanking element via the aperture.

7. An electrical cut-out according to any one of claims 3 to 6 in which the outermost face of the blanking element is substantially smooth.

8. An electrical cut-out according to any one of claims 3 to 7 in which the blanking element comprises an outwardly extending lip for engagement with the base unit thereby to inhibit removal.