An improved electrical junction box

Abstract

An electrical junction box assembly having a housing with an inlet for receiving a cable, and a cable retaining mechanism. The cable retaining mechanism comprising an elongate retaining element and a retaining surface arranged for retaining a cable extending through the inlet. The retaining element is cantilevered at a first end to the housing allowing a cantilevered portion, including a free second end, to flex towards and / or away from the retaining surface. The cable retaining mechanism further comprising a prop member that, when the prop is in use, is positionable against the retaining element selectively in any one of a plurality of different positions to provide a fulcrum for the retaining element that is between the first end and the second end. Through controlling the position of the fulcrum, the flexibility of the cantilevered portion can be adjusted. The prop can also hold the cantilevered portion in a flexed state so as to alter the spacing to the retaining surface. This provides means to adjust the retaining mechanism to suit cables of different gauges and stiffnesses.

Description

[0001] An Improved Electrical Junction Box

[0002] The present invention relates to an electrical junction box assembly.

[0003] A regulatory requirement for electrical junction boxes is that they include a means to clamp or otherwise grip the cable to isolate the electrical connections in the box from stress as a result of the cables being pulled and pushed from outside of the box.

[0004] GB2462595 describes a known electrical junction box with a gripping mechanism for this purpose. With reference to Figs 1 and 2 of GB2462595, GB2462595 comprises removeable gripper elements 46 48 arranged to clamp a cable extending through respective passages 22 20 within the box against a central bar 26. The position of the gripper relative to the bar 26 can be changed by moving it between slots 40 and 50 to accommodate different sized cables.

[0005] Generally this works well, however, because the gripper needs to have different strength and flexibility characteristics compared with that required by the box, it has to be manufactured separately from a different material, and then manually inserted into the box during manufacture. Although it is able to retain a relatively broad range of cable gauges, this range could be improved.

[0006] US435839 relates to a cable locking device that fits into an opening of an electrical box to lock into position a cable extending through the opening. In one embodiment, the device includes a generally square retaining element for use where the electrical box has a circular or regular shaped opening.

[0007] According to a first aspect of the invention there is provided an electrical junction box assembly comprising a housing having an inlet for receiving a cable, and a cable retaining mechanism; the cable retaining mechanism comprising an elongate retaining element and a retaining surface arranged for retaining there between a cable extending through the inlet; the retaining element cantilevered about a first end to the housing allowing a cantilevered portion, including a free second end, of the retaining element to move relative to the housing towards and / or away from the retaining surface; and in which the cable retaining mechanism further comprises a prop member selectively positionable against the retaining element to provide a fulcrum for the retaining element that is between the first end and the second end.

[0008] The retaining element and housing may be separate pieces, however preferably at least a part of the housing and the retaining element are comprised from a single integral piece.

[0009] The cantilevered portion may be configured to flex relative to the housing towards and / or away from the retaining surface.

[0010] When the prop member is positioned against the retaining element to provide the fulcrum, the length of the cantilevered portion that is free to flex away from the retaining surface is reduced and the stiffness of the retaining element increased; a virtue of the stiffness of the retaining element being inversely proportional to its length. This improves the retention of wider gauge cables.

[0011] The prop may be configurable, when positioned against the retaining element, to hold the retaining element in a flexed position with the second end closer to the retaining surface to improve the retention of narrower gauge cables, or further from the retaining surface to improve the retention of wider cables.

[0012] The prop thus provides a means to selectively adjust the flexibility of the retaining element and / or position of the second end of the retaining element relative to the retaining surface.

[0013] The cable retaining mechanism may be configured to allow the prop to be positionable against the retaining element selectively in one of a plurality of positions between the first and second end to position the fulcrum at one of a plurality of different positions between the first and second end, and optionally to hold the second end at one of a plurality of different distances from the retaining surface.

[0014] The retaining element may be formed from a single integral piece. Favourably the single integral piece also defines at least a part of the housing. Favourably the single integral piece also defines the prop member. Thus the whole assembly can be manufactured from a single integral piece. Where so, the prop is favourably connected to the housing through a frangible joint that provides a preferential breaking point through which the prop can be separated from the housing and positioned against the retaining element.

[0015] The housing may provide a cavity for holding one or more electrical connection blocks. One or more walls of the housing may comprise an aperture for the cable to extend into the housing, the inlet comprising a channel extending between the aperture and the cavity.

[0016] The one or more walls may comprise multiple apertures that open into the channel. For example, the housing may comprise two walls, each comprising an aperture arranged on either side of an edge where the two walls meet.

[0017] The prop member may comprise a leg portion and a base portion, the leg extending obliquely away from the base portion, and in which the cable retaining mechanism is configurable to hold the prop member selectively in one of two orientations to hold the second, free, end of the retaining element at one of two different distances from the retaining surface. This allows the prop member’s function to change depending upon the orientation in which it is used.

[0018] The housing may comprise two projections that extend into the inlet from a first side, and the retaining element extends into the inlet from a second side such that the second end of the retaining element lies directly between the two projections. This arrangement compels the cable to curve in two opposite directions as it extends through the inlet serving to isolate the electrical connections within the box from pulling forces made on the cable from outside the box.

[0019] The housing may define a second inlet that extends between a second aperture and the cavity. Where so, the assembly may comprise a further cable retaining mechanism comprising a further elongate retaining element and a further retaining surface arranged for retaining there between a further cable extending through the second inlet; the further retaining element cantilevered about a first end to the housing allowing a cantilevered portion, including a second free end of the further retaining element, to move, e.g. flex, relative to the housing towards and / or away from the further retaining surface; and in which the electrical junction box assembly further comprises a further prop member selectively positionable against the further retaining element to provide a fulcrum for the further retaining element that is between the further retaining element’s first end and the second end free end. The housing and the further retaining element may be comprised from a single integral piece.

[0020] The single integral piece may be comprised from a synthetic plastics material. The single integral piece may be an injection moulded single integral piece.

[0021] According to another aspect of the invention there is provided an electrical junction box assembly comprising: a housing, having an inlet for receiving a cable; and a bracket; a fastening mechanism comprising a (optionally tapered) slot and an elongate (optionally tapered) tongue; wherein one of the slot or elongate tongue is provided on or in an outer side of the housing, and the other by the bracket; wherein the slot is configured to receive the tongue when the housing and bracket are mounted together to retain the bracket and housing together with an interference fit.

[0022] The slot and tongue may be shaped in order that once the tongue is received in the slot, the tongue is keyed within the slot to inhibit the tongue passing out of the slot through a longitudinal aperture of the slot. According to a further aspect of the invention there is provided a method of retaining a cable in an electrical junction box, the electrical junction box comprising a housing having an inlet for receiving the cable, and a cable retaining mechanism; the cable retaining mechanism comprising an elongate retaining element and a retaining surface arranged for retaining there between a cable extending through the inlet; the retaining element cantilevered about a first end to the housing allowing a cantilevered portion, including a free second end, of the retaining element to move relative to the housing towards and / or away from the retaining surface; and and in which the method comprises positioning a prop member against the retaining element between the first and second end to provide a fulcrum for the retaining element that is between the first end and the second end.

[0023] According to another aspect of the invention there is provided an electrical junction box assembly comprising a housing having an inlet for receiving a cable, and a cable retaining mechanism; the cable retaining mechanism comprising an elongate retaining element and a retaining surface arranged for retaining there between a cable extending through the inlet; the retaining element cantilevered about a first end to the housing allowing a cantilevered portion, including a free second end, of the retaining element to move relative to the housing towards and / or away from the retaining surface; and in which the cable retaining mechanism further comprises a prop member selectively positionable against the retaining element in one of a plurality of different positions to either hold the free second end at a different spacing to the retaining surface and / or alter the rigidity of the cantilevered portion.

[0024] The invention will now be described by way of example with reference to the following figures in which: Figure l is a perspective view an electrical junction box from a front end;

[0025] Figure l is a perspective view of the electrical junction box from a rear end with the lid hidden to reveal the box’s interior;

[0026] Figure 3 is a perspective view the electrical junction box from a front end with lid hidden;

[0027] Figure 4 is an underside view the electrical junction box illustrating the base of the electrical junction box;

[0028] Figure 5 is a top view the electrical junction box, with lid hidden, with props in their default non-use positions;

[0029] Figure 6 is a top view the electrical junction box, with lid hidden with one prop in use in a first orientation;

[0030] Figure 7 is a top view the electrical junction box with lid hidden and with one prop in use in a second orientation;

[0031] Figure 8 is a perspective view of the electrical junction box with hinged lid open;

[0032] Figure 9 is a perspective view of an electrical junction box assembly comprising the electrical junction box to which is secured a clip to aid mounting the junction box on a wall or other supporting surface;

[0033] Figure 10 is a perspective view of the electrical junction box and clip positioned for mounting on the junction box;

[0034] Figure 11 is a perspective view of the clip; and Figure 12 is a different perspective view of the clip.

[0035] There is illustrated an electrical junction box assembly. The assembly comprises a housing 1 having a base wall 2, front wall 3, rear wall 4 and side walls 5, which between them define a cavity 6. The housing 1 further comprises a lid member 7 for selectively closing off and providing access to the cavity 6. The lid 7 is hinged to the rear wall 4 through a living hinge 7 A (see Fig 8).

[0036] Within a portion of the cavity 6, lying towards the rear of the housing 1, hereafter referred to as the rear portion 6A, are provided a number of bays 8, in this example four. Each bay 8 is sized to retain one or more electrical connector terminal blocks (not shown), such as, for example those supplied under the brand name Wago(RTM). The bays 8 are defined through subdivision of the cavity 6 by a number of bay walls 9, in this example three, extending upwardly from the base wall 2 and laterally inwards from the rear wall 4.

[0037] At the front of the housing 1, four slots are provided through the housing walls. The front wall 3 is provided with two slots 3A. A further slot 5A is provided in each side wall 5.

[0038] Each slot 3A 5A extends substantially vertically, opening to the top face of its respective wall. With the lid 7 open, this allows cables to be slotted through the wall at a point between the cable’s two ends allowing for faster installation compared with the alternative of feeding an end of the cable through a slot from outside the housing 1.

[0039] A central wall 10 extends upwardly from base wall 2 into the cavity 6. The central wall 10 runs parallel with the side walls 5, extending from the front wall 3 , at a point between the two slots 3 A, towards the rear wall 4. Extending on either side of the central wall

[0040] 10 between the central wall 10 and the side walls 5 are two channels 11. Each channel

[0041] 11 interconnects slots 3 A 5A with the rearward portion 6A of the cavity 6 to provide a conduit for the cable between the slots 3 A 5 A and the rearward portion 6A of cavity 6. The junction box assembly comprises a gripping mechanism associated with each channel 11 configured to grip cables lying within the channels 11 to isolate electrical connections between cables within the bays 8 from the stress of forces on the cables from outside of the housing 1. Each gripping mechanism comprises an elongate gripping member 12 and one or more gripping surfaces between which the cables are gripped.

[0042] Each side wall 5 defines three semi-circular internal projections: a front projection 13 a central projection 14 and rear projection 24. The three projections function to stiffen, i.e. reduce flexure of, the side walls. The front and central projections 13,14 are spaced apart giving rise to an interconnecting side wall portion 5C therebetween having an interior face 5D. The front and central projections 13 and 14 each having an arcuate face 13 A, 14A that faces into the cavity 6. The arcuate faces 13 A 14A extend the height of the side wall 5. Circumferentially spaced apart over each arcuate face 13A 14A is a set of tapered gripping ribs 15 that extend substantially the height of the projections 13.

[0043] The arcuate faces 13A, 14A together with gripping ribs 15 and interior face 5D, in combination, provide the one or more gripping surfaces.

[0044] Each gripper 12 has a first end 12A and a second end 12B. Each gripper 12 is cantilevered about its first end 12A from a central position along the central wall 10. The gripper 12 is orientated to extend rearwardly at an oblique angle from the central wall into the channel 11 towards the side wall 5 with the second end 12B positioned directly between the projections 13 14.

[0045] By virtue of its cantilevered arrangement, a cantilevered portion 12C of each gripper, including the second end 12B is free to flex relative to the centre wall towards and away from the side wall 5 it is facing

[0046] The cantilever portion 12C includes a stud 16 located between the first end and second end that protrudes from a side 12D of the gripper member 12 facing the central wall 10. The stud 16 provides an engagement surface 16A that faces towards the first end 12A of the gripper member 12.

[0047] At the second end, the gripper member 12 terminates with a tapered tooth 17. The tapered tooth 17 extends at an oblique angle laterally from a longitudinal axis X-X (see Fig 6) of the gripper member 12 in a direction away from the first end 12A.

[0048] To strengthen the central wall 10, forward and rearward portions 10A 10B of the central wall 10, being forward of and rearward of the mounting position of the gripper member 12 respectively, are provided with strengthening ribs 18, 19. Strengthening ribs 19, of the rearward portion 10B of the central wall 10, are formed to define an indent 20 on either side of the central wall 10 having opening that faces towards the retaining member 12.

[0049] The relative arrangement of the strengthen ribs 19 and stud 16 provides a recessed space 21 that includes indent 20.

[0050] As shown in Figs 2-5, which illustrate the assembly in an as-manufactured unconfigured state also extending upwardly from the base wall 2 in the cavity 6 are two prop members 2223. Each prop member 2223 comprises a relatively long leg member 22A 23A having a first free end 22B 23B and a second end 22C 23C about which it is connected to a relatively short cross piece 22D 23D. The cross piece is orientated skew to the leg member 22 A 23B.

[0051] Each prop member 2223 is connected to the base wall 2 through a frangible connection 22E 23E that facilitates detachment of the respective prop member 2223 from the base wall 2 when required for use.

[0052] The housing 1, gripper member 12 and props 22, 23 are all formed from a single integral piece of injection moulded synthetic plastics material. Gate marks 25 in the base wall 2 are vestiges of the injection moulded process. To manufacture the gripper member 12 such that it is cantilevered, an aperture 26 extending the length of the gripper member 12 is provided in the base wall 2 directly below each gripper member 12

[0053] Further, the lower edge of gripper member 12 is formed to sit slightly above the base wall 2 in order that the lower edge of the gripper elements 12 does not imping against the base wall 2.

[0054] To install a cable, the lid 7 is opened, and the cable slotted into the channel 11 and one of the slots 3 A 5A through the open face such than the end of the cable end lies within the rearward portion 6A of the cavity 6 for connection to an electrical connector.

[0055] Within the channel 11, the cable extends through a gap 27 between the second end 12B of the gripper member 12 and interconnecting side wall portion 5C. The gap 27 is narrower than the gauge of the cable such that the cable is pinched between the second end 12B and face 6D. The oblique orientation of the tapered tooth 17 results in the point of the tooth 17 engaging the cable’s outer sheath at an angle closer to normal increasing the frictional force exerted on the cable.

[0056] To aid in the insertion of cables the gripper member 12 has a height that tapers down towards its free second end 12B so as to provide the gripper member with a sloping top edge 12E that guides cables presented against the top edge towards the gap 27

[0057] The cable may additionally engage against the one or more of the ribs 15 of either or both protrusions 13, 14 to provide additional frictional contact points for gripping the cable.

[0058] When the cable is pulled the cable will naturally try to straighten which causes the cable to urge with greater force against its contact points on the gripper member 12 and projections 13 14 inhibiting movement of the cable. To improve the gripping of wider gauge cables, the assembly comprises additional gripping elements 28 that extend diagonally inwardly and rearwardly from each front corner of the housing 1, between slots 3 A 5 A, to grip the cable before it extends passed the front projection 13. The position of the projection 28 in the corner also aids to stiffen the housing 1 at the corner to compensate for the weakening effect of the slots 3 A 5A.

[0059] One or more further cables may then be installed either in a stacked arrangement on top of the first cable and / or through the second channel.

[0060] Once installed, the lid 7 is closed against the top face of the front wall 3 and side walls 5. The lid 7 is held closed through a clip fasteners 29 integrally formed in the top edge of the front and side walls 3, 5.

[0061] This default configuration illustrated in Figs 2-5 works well for gripping cables of a certain range of gauges. Figures 6 and 7 illustrate the use of the prop member 22 23 in two different in-use orientations to provide improved gripping for wider and narrower gauge cables.

[0062] Fig 6 illustrates use of the prop to configure the gripping member 12 for improved gripping of wider gauge cables compared with the default configuration.

[0063] With the lid 7 open, one of the props 22 23, or both if cables are to be passed through both channels 11, are detached from the base wall 2 through severing of the frangible connectors 22C 23 C.

[0064] The cross piece 22D of the prop 22 is inserted into the recessed space 21 in an orientation inverted from that in which it was connected to the base wall 2. Namely the end through which it was connected to the base wall 2, first. In this arrangement the leg 22A is oriented with its free end 22B disengaged from the gripper member 12. Retained within the recessed space 21, the prop 22 provides a fulcrum about which the gripping member 12 can flex away from the side wall 5 on the opposite side of the channel 11 in reaction to force exerted by a cable within channel 11. The affect is a shortening of the length of the cantilevered portion 12C and thus consequently an increase in the stiffness of the cantilever portion 12C against flexing in the direction away from side wall 5.

[0065] This benefits the gripping of wider cables, where the gripping member may otherwise be vulnerable to flexing against the force of a straightening cable to an extent sufficient to allow for the cable to straighten.

[0066] Fig 7 illustrates use of the prop to configure the gripping member for improved gripping for narrower gauge cables compared with the default configuration.

[0067] As before, with the lid 7 open, one of the props 2223, or both if cables are to be passed through both channels 11, are detached from the base wall 2 through severing of the frangible connectors 22E 23E.

[0068] The cross piece 22D of the prop 22 is inserted into the recessed space 21 in the same orientation by which it was connected to the base wall 2. In this arrangement the free end 22B of the leg 22 A engages against the gripper member 12 at a position between the stud 16 and second end 12B holding the gripper member in a flexed position with second end 12B closer to face 5D narrowing gap 27. To locate the prop 22 in position, it may be necessary to manipulate the gripper member 12 by hand into the flexed position.

[0069] In this configuration, the free end of the leg 22A provides a fulcrum that is closer to the second end of the gripper 12 increasing the gripper’s resistance to flexing.

[0070] Although the above described the positioning of the props prior to insertion of the cable, it is possible instead, and perhaps favourably, to first locate the cable in the channel 11, and then to locate the prop, if needed, into the required position against the gripping member 12. Because the cable is already in position, this order may make it easier to ascertain the most effective position for the prop.

[0071] Figures 9-12 illustrates the junction box 1 and an angle bracket 30 to facilitate mounting of the junction box 1 onto a wall or other supporting surface.

[0072] The bracket 30, illustrated in isolation in Figs 11 & 12, and mounted to the box 1 in Fig 9, is of ‘L’ shaped form, comprising a first plate like side 31 and a second plate like side 32. Provided on an inner face of the first side 31 are two substantially parallel elongate tongues 33 that extend the length of the first side. Each tongue 33 has a width that varies along its length. Each is relatively wide at the end towards the corner of the bracket 30 and gradually tapers (narrows) towards the free end of the side 31. Two slot apertures 34 are provided through the first side 31 between the tongues 33, one opening to the free edge of the first side. A further two apertures 35 are provided in the second face 32. The apertures 34, 35 enable either side 31 32 to be selectively fastened to a wall by means of screws, bolts or other like fasteners. Each aperture 34, 35 is countersunk to receive the head of the fastener.

[0073] For the purpose of being mounted to the bracket 30, the outer facing side of wall 5 of the housing 1 is provided with parallel vertically extending non-through slots or grooves 29. Each extending the height of the wall 5, and opening out at the top and bottom edges of the side walls 5.

[0074] The grooves 29 have a width that narrows gradually along their length from the base 2 to the top edge of side 5

[0075] The grooves 29 are sized and spaced apart by a distance to receive the tongues 33 of the bracket through a sliding action in which the tongues pass into the grooves 29 at one end. The tapered nature of the grooves 29 and tongue 33 provide an interference fit once the tongue 33 are seated within grooves 29 to releasably retain the box 1 to the bracket 30.

[0076] Additionally the grooves 29 and tongues are profiled to key together to inhibit removal of the tongues through the grooves’ 29 elongate longitudinal openings. In the current example, each groove has a width that increases with depth away from its elongate longitudinal opening.

[0077] Variation to the above exampled embodiment is possible. A non-limiting list of example variations are provided below.

[0078] The arrangement of a central wall 10 with supporting ribs 18, 19 reduces the volume of plastic required to form the assembly. However, alternatively, the central wall 10 may be thicker and an indent provided within the wall 10.

[0079] The number of slots provided in the front wall and side wall may differ from two. It is not essential that there is provided slots in both the front wall and the side walls.

[0080] The lid 7 may be hinged to a different wall, though it favourable that that whichever wall is its hinged to does not have a slot equivalent to 3 A formed within it. The lid may not be hinged to the wall at all, though this is less preferred. The lid may be formed from a piece separate, and non-integral, with the housing.

[0081] The gripping mechanism 12 may instead be cantilevered to project into the channels 11 from the side walls, and the central wall provided with equivalent projections to those of 13 & 14.

[0082] The housing 1 may be provided without the central wall 10 to define only a single channel with a single retaining member 12 instead cantilevered to a side wall 5. The projections 13, 14 may take forms other than semi-circular to provide faces shaped other than arcuate.

[0083] Although less preferred, the semi-circular projections may be omitted. Instead the inside face of the side walls 5 may be provided with tapered gripping ribs or teeth. Although less preferred, the function of the projections may instead be provided by projections extending upwardly from the base wall 2 that are close to by separate from the side walls 5.

[0084] It is possible, in principle, to manufacture the single integral piece assembly using an additive manufacture process though at significantly higher manufacturing cost. However, where so, the apertures 26 in the base wall may be omitted.

[0085] Although it is preferred that the prop member is directly attached to a wall of the housing through a frangible connection, the prop member could instead be connected to the housing through a direct connection to the retaining element.

[0086] The bracket 30 could be used to support variant junction boxes having no cable retaining mechanisms or cable retaining mechanisms differing to that described above.

Claims

Claims1. An electrical junction box assembly comprising a housing having an inlet for receiving a cable, and a cable retaining mechanism; the cable retaining mechanism comprising an elongate retaining element and a retaining surface arranged for retaining there between a cable extending through the inlet; the retaining element cantilevered about a first end to the housing allowing a cantilevered portion, including a free second end, of the retaining element to move relative to the housing towards and / or away from the retaining surface; and in which the cable retaining mechanism further comprises a prop member selectively positionable against the retaining element to provide a fulcrum for the retaining element that is between the first end and the second end.

2. An electrical junction box assembly according to claim 1 wherein the housing and the retaining element are comprised from a single integral piece, and in which the cantilevered portion is configured to flex relative to the housing towards and / or away from the retaining surface.

3. An electrical junction box according to claim 1 or 2 wherein the cable retaining mechanism is configured to selectively retain the prop against the retaining element in any one of a plurality of positions to hold the second end at any one of a plurality of different distances from the retaining surface and / or to position the fulcrum at one of a plurality of different positions between the first and second end.

4. An electrical junction box assembly according to any previous claim wherein the prop member is configured, when positioned against the retaining element, to hold the retaining element in a flexed position with the second end closer to the retaining surface.

5. An electrical junction box assembly according to claim 3 or 4 wherein the prop comprises a leg portion and base portion the leg portion extending away obliquely from the base portion and in which the cable retaining mechanism is configurable to allow the prop member to be held selectively in one of two orientations to hold the second end at one of two different distances from the retaining surface.

6. An electrical junction box assembly according to any claim 2-5 wherein the single integral piece defines the prop member, the prop member is connected through a frangible connector to the housing to allow the prop member to be detached from the housing prior to being positioned against the retaining element.

7. An electrical junction box assembly according to any previous claim wherein the housing comprises two projections that extend into the inlet from a first side, and the retaining element extends into the inlet from a second, opposite, side such that the second end lies between the two projections.

8. An electrical junction box assembly according to any previous claim wherein the housing comprises a base wall to which the retaining element is directly connected.

9. An electrical junction box assembly comprising a housing having an inlet for receiving a cable; said housing comprising a side wall provided with a groove having a width that tapers along its length; and further comprising a bracket for supporting the housing to a supporting structure, said bracket comprising aprotrusion having a width that tapers about its length so as to be received in the groove and retained therein by an interference fit.

10. An electrical junction box assembly according to claim 9 in which the slot and the protrusion are shaped in order that once the protrusion is received in the groove, the protrusion is keyed within the groove to inhibit separation of the housing from the bracket.

11. An electrical junction box assembly comprising: a housing, having an inlet for receiving a cable; and a bracket; a fastening mechanism comprising a slot and an elongate tongue; wherein one of the slot or elongate tongue is provided on or in an outer side of the housing, and the other by the bracket; wherein the slot is configured to receive the tongue when the housing and bracket are mounted together to retain the bracket and housing together with an interference fit.

12. An electrical junction box assembly according to claim 11 wherein the slot is tapered along its length, and the tongue is tapered along its length.

13. An electrical junction box assembly according to claim 11 or 12 in which the slot and tongue are shaped in order that once the tongue is received in the slot, the tongue is keyed within the slot to inhibit the tongue passing out of the slot through an longitudinal aperture of the slot .

14. A method of retaining a cable in an electrical junction box, the electrical junction box comprising a housing having an inlet for receiving the cable, and a cable retaining mechanism; the cable retaining mechanism comprising anelongate retaining element and a retaining surface arranged for retaining there between a cable extending through the inlet; the retaining element cantilevered about a first end to the housing allowing a cantilevered portion, including a free second end, of the retaining element to move relative to the housing towards and / or away from the retaining surface; and and in which the method comprises positioning a prop member against the retaining element between the first and second end to provide a fulcrum for the retaining element that is between the first end and the second end.

15. A method according to claim 14 wherein, prior to positioning the prop member against the retaining element, the prop member is detached from the housing through severing a frangible connector through which the prop member is mounted to the housing.

16. A method according to claim 14 or 15 wherein the cable is inserted through the aperture after the prop member is positioned against the retaining element.

17. A method according to claim 14 or 15 wherein the cable is inserted through the aperture prior to the prop member being positioned against the retaining element.

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