Abstract
The present invention provides an electrical connector, comprising a shuttle member for receiving a stripped multi-core cable (such as a twin and earth conductor cable), the shuttle member including a core guide means and a resilient clip member for each of the stripped cores to be received. A body portion is configured to support at least one shuttle member in sliding engagement and includes an array of terminal connections, each connection having a shaped contact to receive a respective clip member of the shuttle member. Each shaped contact defines a jaw member operable to compress a respective clip member when the shuttle member is fully engaged with the body portion to thereby grip the stripped cores of the multi-core cable. The electrical connector has particular application as an electrical junction box for lighting circuits.
Claims
1. An electrical connector, comprising: a shuttle member for receiving a stripped multi-core cable, the shuttle member including a core guide means and a resilient clip member for each of the stripped cores to be received; and a body portion configured to support at least one shuttle member in sliding engagement and including an array of terminal connections, each connection having a shaped contact to receive a respective clip member of the shuttle member; wherein each shaped contact defines a jaw member operable to compress a respective clip member when the shuttle member is fully engaged with the body portion to thereby grip the stripped cores of the multi-core cable.
2. The electrical connector of claim 1, wherein the shuttle member has a first end for receiving the multi-core cable and an opposing end adapted to be retained within the body portion.
3. The electrical connector of claim 1, wherein the resilient clip members are integral to the shuttle member.
4. The electrical connector of claim 1, wherein each resilient clip member defines a compressible jaw operable to engage with and grip a stripped core.
5. The electrical connector of claim 1, wherein each resilient clip member is conductive.
6. The electrical connector of claim 1, wherein each resilient clip member has a substantially flattened C-shaped profile.
7. The electrical connector of claim 1, wherein the resilient clip members are disposed adjacent to each other.
8. The electrical connector of claim 1, wherein the shuttle member comprises three resilient clip members.
9. The electrical connector of claim 1, wherein the body portion is substantially elongate.
10. The electrical connector of claim 1, wherein the body portion is configured to support and retain at least two shuttle members.
11. The electrical connector of claim 1, wherein the body portion is operable to lock the shuttle member when the shuttle member is fully engaged with the body portion.
12. The electrical connector of claim 1, wherein the array of terminal connections comprises a spaced arrangement of conductive contacts.
13. The electrical connector of claim 12, wherein the spaced arrangement has a substantially H-shaped configuration.
14. The electrical connector of claim 13, wherein each H-shaped conductive contact corresponds to a respective one of a live, neutral or earth terminal.
15. The electrical connector of claim 1, wherein the core guide means is disposed internally to the shuttle member.
16. The electrical connector of claim 1, wherein the core guide means comprises a baffled channel for each of the stripped cores to be received, each baffled channel being operable to guide the stripped cores into a respective clip member.
17. The electrical connector of claim 16, wherein each baffled channel is configured and dimensioned so as to receive only a single stripped core.
18. The electrical connector of claim 1, wherein the shuttle member further comprises a gripping means for gripping the outer surface of the multi-core cable when the shuttle member is fully engaged with the body member.
19. An electrical circuit, comprising: a power source; and at least one electrical connector according to claim 1.
20. The electrical circuit of claim 19, further comprising at least one light source connected to the power source and at least one of the electrical connectors.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] Embodiments of the present invention will now be described in detail by way of example and with reference to the accompanying drawings in which:
[0051] FIGS. 1(a)-1(e)show an exemplary embodiment of an electrical connector according to the present invention with the shuttle member not fully engaged1(a) cross-section along line C-C of side view of 1(b); 1(c) top plan view and 1(d) cross-section along line B-B; and 1(e) side perspective view;
[0052] FIGS. 2(a)-2(g)show an exemplary embodiment of a shuttle member according to the present invention with the cable not inserted2(a) front view of shuttle member; 2(b) cross-section along line B-B of side view of 2(c); 2(d) top plan view and 2(e) cross-section along line A-A; 2(f) side perspective view; and 2(g) rear end of shuttle member;
[0053] FIGS. 3(a)-3(g)show an exemplary embodiment of a shuttle member according to the present invention with the cable inserted3(a) front view of shuttle member; 3(b) cross-section along line B-B of side view of 3(c); 3(d) top plan view and 3(e) cross-section along line A-A; 3(f) side perspective view; and 3(g) rear end of shuttle member;
[0054] FIG. 4shows a partial cut-away of the electrical connector of FIG. 1(e) with the shuttle member not fully engaged;
[0055] FIG. 5Ashows a close-up view and partial cut-away of an exemplary embodiment of the resilient clip members with the shuttle member not fully engaged;
[0056] FIG. 5Bshows a close-up view and partial cut-away of an exemplary embodiment of the resilient clip members with the shuttle member fully engaged;
[0057] FIGS. 6(a)-6(f)show the electrical connector of FIGS. 1(a)-1(e) with the shuttle member fully engaged6(a) cross-section along line A-A of side view of 6(b); 6(c) top plan view and 6(d) cross-section along line B-B; 6(e) side perspective view; and 6(f) top end view;
[0058] FIGS. 7(a)-7(f)show an exemplary embodiment of an array of terminal connections7(a) side perspective view; 7(b) top plan view; 7(c) side view; 7(d) front view; 7(e) opposing side view; and 7(f) bottom view;
[0059] FIGS. 8(a)-8(f)show another exemplary embodiment of an array of terminal connections8(a) side perspective view; 8(b) top plan view; 8(c) side view; 8(d) front view; 8(e) opposing side view; and 8(f) bottom view;
[0060] FIG. 9shows a schematic view of an example circuit according to the present invention; and
[0061] FIGS. 10A & 10Bshow schematic views of further example circuits according to the present invention.
DETAILED DESCRIPTION
[0062] Referring to FIGS. 1(a)-(e), there is a shown a particularly preferred embodiment of an electrical connector 100 according to the present invention. In exemplary embodiments the electrical connector 100 is in the form of an electrical junction box for an electrical lighting circuit (as shown in FIGS. 9, 10A & 10B), and in the example of FIGS. 1(a)-(e) is being used with a twin and earth (3-core) electrical cable 102. The cable 102 is a flat-type cable in which the 3-cores 102a are arranged adjacent to each other as best shown in FIG. 1(e).
[0063] The electrical connector 100 comprises a body portion 104 configured to support and retain at least one shuttle member 106 in sliding engagement (i.e. for movement back and forth). In the example of FIGS. 1(a)-(e), the body portion 104 is shown with four shuttle members 106, which are not yet fully advanced into or engaged with the body portion 104. For reasons of clarity, only one cable 102 is shown in FIGS. 1(a)-(e), however it is to be appreciated that in practice each shuttle member 106 would have a corresponding cable 102.
[0064] As shown in FIGS. 1(a)-(e), the body portion 104 is substantially elongate in form and is dimensioned so as to be essentially long and thin, with a maximum width dimension not much larger than the width dimension of the shuttle member 106 itself. A major advantage of an elongate body portion 104 is that the present electrical connector is able to pass through, for example, a standard 58 mm hole of a conventional recessed light fitting, and indeed can pass through holes as small as 32 mm in diameter.
[0065] The function of the body portion 104, in addition to retaining the shuttle members 106 in sliding engagement, is to provide a support means for the array of terminal connections 108 (see FIG. 1(d) and FIGS. 7 & 8). The array 108 is disposed within the inner central volume of the body portion 104 and comprises a spaced arrangement of conductive contacts. In the example of FIGS. 1(a)-(e), the spaced arrangement has a substantially H-shaped configuration, with each end portion at the top and bottom of the vertical arms of the H having a shaped contact defining a jaw member 108a (see FIGS. 7 & 8). The jaw member 108a has a substantially arcuate or flattened C-shaped profile, which is configured and dimensioned to receive a respective resilient clip member 110 of the shuttle member 106 (as discussed below in relation to FIGS. 5A & 5B).
[0066] Each H-shaped conductive contact corresponds to a respective one of a Live, Neutral or Earth terminal. In the case of a 3-core mains cable, as shown in FIGS. 1(a)-(e), the terminal connections are arranged such that there are three H-shaped contacts disposed adjacently and spaced apart from each other by an insulated support (see FIGS. 7(a) & 8(a)).
[0067] Referring to FIGS. 2(a)-(g) & 3(a)-(g), there is shown a particularly preferred embodiment of a shuttle member 106 according to the present invention. For clarity of illustration, the shuttle member 106 is shown without the body portion 104. However, it is to be understood that the shuttle member 106 is not intended to be a separate component and is thus always retained within the body portion during use. The shuttle member 106 is configured to receive the previously stripped cable 102, as shown in FIGS. 2(a)-(g), and then afterwards as inserted in FIGS. 3(a)-(g). The shuttle member 106 is substantially rectangular in shape and comprises a first end 106a to receive the cable 102 and an opposing end 106b which is retained within the body portion 104. The shuttle member 106 is operable to slide relative to the body portion.
[0068] The first end 106a comprises an open channel of circular cross-section (see FIG. 2(f)) which is intended to receive and guide the cable 102 towards the core guide means 112 (see FIG. 2(b)). The open channel is dimensioned so as be only slightly larger in width than the width dimension of the cable 102 (see FIG. 3(f)).
[0069] At the opposing end 106b of the shuttle member 106 (i.e. the end retained within the body portion 104), there is disposed a plurality of open slots 114 (see FIG. 2(d)), with one slot for each of the 3 stripped cores 102a to be received. The slots 114 extend parallel to the longitudinal axis of the shuttle member 106 and are disposed adjacent to each other. The resilient clip members 110 are integral to the shuttle member 106 and are arranged such that there is one resilient clip member 110 disposed in each of the slots 114 of the shuttle member 106.
[0070] Each resilient clip member 110 takes the form of a conductive metal contact having a substantially flattened C-shaped profile (see FIGS. 2(e) & 5A). The C-shaped profile of the resilient clip member 110 defines a compressible jaw, which when compressed together is operable to engage with and grip a core 102a of the cable 102. A resilient clip member 110 is disposed in each respective slot 114 such that the open part of the jaw faces inwards towards the centre of the shuttle member 106 (see FIG. 2(e)). Therefore, the closed arcuate shaped part of the resilient clip member (which effectively acts as a hinge for the jaw) faces outwards and is accessible through each respective open slot (see FIGS. 2(d) & 2(f)).
[0071] The core guide means 112 is also disposed internally to the shuttle member 106 and is located at the bottom end of the open channel which receives the cable 102 (see FIG. 2(b)). The core guide means 112 comprises a baffled channel 112a for each of the stripped cores 102a of the cable 102, which in the example of FIGS. 2(a)-(g) means three baffled channelsone each for a Live, Earth and Neutral core of the cable 102. The function of each baffled channel 112a is to guide the stripped cores 102a towards each of the respective clip members 110, which are so arranged such that their open jaws face towards a respective baffled channel 112a (see FIGS. 2(b) & 2(e)).
[0072] As shown in FIG. 2(b), the core guide means comprises a V or delta shaped funnel arrangement with three openings leading to a respective baffled channel 112a. As the cable 102 is inserted into the opening of the shuttle member 106, the adjacently arranged stripped cores 102a then encounter the three openings, which due to the baffle arrangement of the channels 112a, results in each of the stripped cores 102a being guided into a respective one of the channels 112a (see FIG. 3(b)). The core guide means 112 is configured such that the stripped cores 102a of the cable 102 are splayed apart as the cable 102 is inserted into the shuttle member 106, leading to a separation of the stripped cores 102a of at least 3 mmwhich is the regulated minimum separation for 240 Vac.
[0073] Each opening and baffled channel 112a is configured and dimensioned so as to receive only a single stripped core 102a. Therefore, there is no possibility of more than one stripped core 102a being able to enter into the same channel 112a of the core guide means 112. Such a feature therefore advantageously facilitates easy connection of the cable 102 to the connector 100, as the installer need only offer up the stripped cable 102 to the opening of the shuttle member 106 and insert the cable 102, while the core guide means 112 automatically guides the stripped cores 102a to their respective channels 112a and splays the exposed conductors of the stripped cores 102a apart in accordance with the regulated separation.
[0074] In practice, the cable is typically stripped back such that about a 20 mm length is inserted into the shuttle member 106, the 20 mm length consisting of about 15 mm of exposed conductor (e.g. wire) and about 5 mm of insulated or sheathed core. The 5 mm of insulation is necessary to maintain creepage and clearance of the exposed conductors, when they are in place in the shuttle member 106 and to avoid any possibility of electrical shorting between the exposed conductors.
[0075] To assist an installer with the orientation of the cable 102 (to avoid an inadvertent wiring error), the open end 106a of the shuttle member 106 is marked with the polarity of the connection (see FIGS. 2(f) & 3(f)), so that a L for live or a N for neutral is indicated on the body of the shuttle member 106, so that the installer knows which way round the cable 102 needs to be before inserting the cable 102 into the shuttle member 106, as shown in FIGS. 3(a)-(g).
[0076] Once the cable 102 has been inserted into the shuttle member 106, the exposed conductors of the stripped cores 102a then reside in each of a respective open jaw of a resilient clip member 110 (see FIGS. 3(e) & 5A). However, at this stage, since the clip members 110 are not under compression (since the shuttle member 106 has not yet been advanced into its locked position within the body portion 104), and so the exposed conductors of the stripped cores 102a are not yet gripped by the clip members 110.
[0077] As shown in FIGS. 2(c), 2(e) & 2(f) & FIGS. 3(e) & 3(f), the shuttle member 106 further comprises an automatic cable gripping means 116 for gripping the outer surface of the cable 102. The cable gripping means 116 takes the form of a pair of pivotable or hinged arm members attached to the body of the shuttle member 106 with a respective hook at each end. Each arm 116 is disposed on an opposite side of the shuttle member 106, such that the hook can automatically engage with the outer sheath of the unstripped portion of the cable 102 when the shuttle member 106 is slidingly advanced further into the body portion 104 so that it is fully engaged. The arms 116 are then pressed against the cable 102, thereby firmly gripping the cable 102. Thereafter, cable 102 could only be removed with considerable force.
[0078] The shuttle member 106 also comprises a pair of protrudences or elongate arms 118 integral to the body of the shuttle member 106 and which serve as latches for latching the shuttle member 106 to the body portion 104, enabling the body portion 104 to retain the shuttle member 106, and also for gripping the shuttle member during manipulation, e.g. when inserting the cable 102 etc. The protrudences 118 extend along the longitudinal axis of the cable shuttle member 106 and are texturised to facilitate grip of the shuttle member 106 during sliding advancement into the body portion 104.
[0079] The array of terminal connections 108 is arranged within the body portion 104 such that when the shuttle member 106 is advanced further into the body portion 104 by pushing on the cable 102, the resilient clip members 110 of the shuttle member 106 engage with a respective one of the jaw members 108a of the shaped contacts (see FIGS. 4 & 5Ain these figures the body portion 104 has not been drawn for clarity reasons). As the resilient clip members 110 are forced into the jaw members 108a of the shaped contacts, the clip members 110 are then compressed and deflected by the jaw members 108a, causing the open jaws of the clip members 110 to close around a respective exposed conductor of a stripped core 102a of the cable 102, as shown in FIG. 5B.
[0080] It is important, however, to ensure that shuttle member 106 does not advance into the body portion 104 before the cable 102 is fully inserted into the shuttle member 106, since otherwise, if the exposed conductors of the stripped cores 102a are not in their correct positions, the open jaws of the resilient clip members 110 will begin to close without gripping the exposed conductors 102a. However, motion of the shuttle member 106 is at least initially resisted by the resilience of the clip members 110 themselves (i.e. resisting insertion into the jaw members 108a) and by the latching mechanism between the shuttle member 106 and the body portion 104. So only when an installer provides sufficient force, is the shuttle member 106 then able to advance into the body portion 104 towards its fully engaged or locked position, by which time the cable 102 and the exposed conductors of the stripped cores 102a should all be in their correct positions. This action can all be achieved by the installer pushing on the cable 102 with one hand and holding the body portion 104 with his other hand.
[0081] When the shuttle member 106 is locked in position (as shown in FIGS. 6(a)-(f)the cable 102 not being shown for clarity reasons), the resilient clip members 110 then reside within the jaw members 108a of the shaped contacts and a firm grip of the exposed conductors of the stripped cores 102a is then achieved by each respective clip member 110 (see FIG. 5B). The cable 102 is then consequently secured and a safe and reliable electrical connection is made between each respective exposed conductor, clip member 110 and shaped contact of the body portion 104without any risk that the exposed conductors can become lose or otherwise pop out of the shaped contacts.
[0082] To facilitate engagement with the exposed conductors of the stripped cores 102a of the cable 102, each resilient clip member 110 includes a recessed notch 110a at the edge of each jaw member to receive and grip the exposed conductors of the cable 102 as the clip member 110 is compressed. The recessed notch 110a is semi-circular in form (see FIG. 5A).
[0083] As shown in FIG. 5A, the leading edges of the jaw members 108a of the shaped contacts also comprise a lipped portion 108a to narrow the opening of the jaw member 108a to thereby enhance compression of the resilient clip member 110 (see FIG. 5B).
[0084] As described, the body portion 104 is operable to lock the shuttle member 106 into the body portion 104 when the shuttle member 104 is fully engaged. The protrudences 118 on the shuttle member 106 latch against reciprocal detents 120 in the interior of the body portion 104 (see FIG. 6(a)), resulting in a non-reversible connection between the shuttle member 104 and the body portion 106. By non-reversible we mean that the shuttle member 106 cannot now be withdrawn from its locked position without excessive force, resulting in damage to either the shuttle member or body portion, or both the shuttle member and body portion.
[0085] Referring to FIGS. 7(a)-(f) & 8(a)-(f), there is shown example arrangements of the terminal connections for use with the electrical connector of the present invention. As described above, these terminal connections are disposed within the body portion 104 and serve to provide both electrical connectivity between the cables and to compress the resilient clip members 110 of the shuttle member 106 by way of the jaw members 108a.
[0086] As shown in FIGS. 7(a)-(f) & 8(a)-(f), the terminal connections have a substantially H-shaped configuration, with each end portion at the top and bottom of the vertical arms of the H having a shaped contact defining the jaw member 108a. In the example shown, each H-shaped contact corresponds to a respective one of a Live, Earth or Neutral terminal disposed adjacently and spaced apart from each other by an insulated support 122.
[0087] The H-shaped contacts in FIGS. 7(a)-(f) are configured such that a discontinuity or insulated break is formed in one or more of the H-shaped contacts which are then electrically connected to one or more other of the contacts (see FIG. 7(e)), so that the electrical connector can be used as a switch and light junction unit (as shown in FIGS. 9, 10A & 10Bdenoted as a Type 1 electrical connector). By contrast, in FIGS. 8(a)-(f), the H-shaped contacts are configured so that each contact is continuous and conductive throughout the contact, and is isolated from the others, so that the electrical connector can be used as a spur or light junction unit (as shown in FIGS. 9, 10A & 10Bdenoted as a Type 2 electrical connector).
[0088] FIGS. 9, 10A & 10B show example circuit layouts for possible lighting circuits constructed using the electrical connector of the present invention. It should be understood that these circuits are in no way limiting and thus represent merely illustrative examples of how a lighting circuit may be wired up.
[0089] In FIG. 9, there is shown a Type 1 electrical connector 100 in which the junction box acts as a switch and light junction unit 100.sub.1, such that it can receive power from a power source (POWER IN) on cable 102.sub.1 and provide an output power (POWER OUT) on cable 102.sub.2. A switch 124 on cable 102.sub.3 controls the availability of power to a light 126 connected to the unit 100.sub.1 via cable 102.sub.4. Alternatively, one or more additional lights 128 could be connected to the unit 100.sub.1 via an electrical connector 100 acting as a spur/light junction unit 100.sub.2 to thereby extend the lighting circuit.
[0090] An extended lighting circuit is shown in FIG. 10A, in which a spur/light junction unit 100.sub.2 has been connected to a switch and light junction unit 100.sub.1. An additional power line has been taken from the unit 100.sub.1 and acts as the input power for an additional switch and light junction unit 100.sub.1. A further switch 124 serves to control the power to an additional spur/light junction unit 100.sub.2, to which are attached more lights 128.
[0091] In an alternative circuit as shown in FIG. 10B, the lighting can also be extended by taking an additional power line from the spur/light junction unit 100.sub.2, which can then act as the input power for an additional switch and light junction unit 100.sub.1. A further switch 124 serves to control the power through the unit 100.sub.1, to which are attached more lights 128.
[0092] Therefore, as can be appreciated from FIGS. 9, 10A & 10B, there are numerous possibilities and permutations for wiring a lighting circuit using the electrical connector of the present invention. Indeed, it is evident that the circuit is inherently scalable and can be extended whenever a change of lighting is required and/or when a domestic residence or commercial property is altered or changed for some reason.
[0093] Although the electrical connector of the present invention is ideally suited as a low-profile electrical junction box for lighting circuits, it will be recognised that one or more of the principles of the invention may extend to other connector and/or circuit types, whereby it is required to quickly and reliably connect one or more multi-core cables together to ensure a safe and maintenance-free electrical connection.
[0094] Thus, the above embodiments are described by way of example only. Many variations are possible without departing from the invention.
