GB2323220A - An electrical junction box - Google Patents

Abstract

An electrical junction box comprises a housing (30,30A) which can locate, by means of lugs (18), and contain a length of conventional multi connector strip (12) comprising terminals to which electrical wires (2,4) can be connected while the connector strip is separated from the housing. The housing has arrangements (24A,25A) to provide for exit and egress of the electrical wires (2,4) and is closeable. The housing (30A) can be closed by folding it about an integral hinge (34), Figure 6 or by inverting an identical housing (28) and applying it over the housing (30), Figure 7.

Description

AN ELECTRICAL JUNCTION BOX This invention relates to electrical junction boxes and is particularly but not exclusively concerned with such boxes which are used to contain joints made between electrically conductive cables in a wiring system.

Devices of that type are well-known in the electrical contracting industry and are readily available for such usage as well as for do-it-yourself enthusiasts. Such devices normally comprise an enclosure having provided therein a number of terminals into which the bared ends of cables may be inserted and retained securely therein by means of clamping screws.

In such an arrangement an ingoing and an outgoing cable may be clamped within the same terminal, or alternatively, two or more terminals may be interconnected within the enclosure usually by solid brass connecting strips.

Because of the location of the various terminals within the enclosure and the needs to clamp different cable ends to different terminals , the cables often need to be cut off to different lengths and routed within the same box. When the enclosure, or junction box as they are generally referred to, is fast to a wall or floor of a loft or attic, or to beams or rafters of a building, the threading and clamping of the cables to be joined is difficult and the working position of the contractor or installer is uncomfortable resulting occasionally in a rushed or uncompleted operation.

Sometimes such interconnections are made by using multi connector strips. Such strips normally comprise a plurality of brass tubes forming terminals each with two clamping screws, the tube terminals being received within through passages in a nylon strip which may readily be severed into lengths containing the required number of tube terminals and with the head of the screws retaining the tube terminals within the nylon strip. Such connector strips are available in various ratings e.g. 5, 15 and 30 amps. However such connectors rarely comply with safety regulations as electrically live components are only partially protected from accidental touching, either by persons or other components within the environment.

According to the invention there is provided an electrical junction box comprising a housing which can contain a length of multi-connector strip, can allow exit and egress of electrical cables, which cables are to be electrically connected by the multi-connector strip, and can be closed.

The housing may include means for locating a length of multi-connector strip. Such means may comprise upstanding lugs to engage within slots or grooves formed in the multiconnector strip.

The housing may comprise a main body and a possibly separate cover member. The cover member may be secured to the main body by ties or clips or by inter-engaging parts formed on the body and the cover.

The main body member and the cover may be identical, in use one being inverted for assembly with the other to form a straight-through junction box.

Alternatively, the housing may be provided as two portions joined by an integral hinge portion and folded over to bring the two portions together.

The housing of the junction box may be formed by a plurality of relatively moveable parts, interlocking means may be provided on such parts to provide for interlocking engagement and such interlocking engagement may be disengagable only by a tool acting on at least one of the parts of the housing of the junction box.

In order to allow for rapid opening of a junction box when e.g. further additions are to be made to cable circuitry, and in order to comply with at least some of the stipulations of Standards relating to protection against direct contact by insulation of live parts, means may be provided in form of a key or other tool which can be used readily and safely to open the junction box.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which: Figure 1 is a plan view of a first embodiment of a junction box in accordance with the invention, the box being shown with a cover removed; Figure 2 is a sectional view on line II-II of Figure 1; Figure 3 is a plan view of a second embodiment of a junction box according to the invention; Figure 4 is a sectional view on line IV-IV of Figure 3; Figure 5 is an exploded perspective view of the embodiment of Figures 3 and 4; Figure 6 is a perspective view of a third embodiment of a junction box according to the invention; Figure 7 is an exploded perspective view of a fourth embodiment of a junction box according to the invention; Figure 8 is a scrap section view of part of a jointing device on the embodiment of Figure 7; Figure 9 is a plan view of a fifth embodiment of a junction box according to the invention; Figure 10 is a sectional view on line X-X of Figure 9; Figure 11 is a sectional view on line XI-XI of Figure 10; Figure 12 is a scrap section view on line XII-XII of Figure 10; Figure 13 is a plan view of a sixth embodiment of a junction box according to the invention; Figure 14 is a perspective view of the embodiment of Figure 13 in an opened configuration; Figure 15 is a perspective view of the embodiment of Figure 13 and 14 in a part closed configuration; Figure 16 is a perspective view of the embodiment of Figures 13 to 15 in a fully closed configuration; Figure 17 is a perspective view showing a closed assembly of parts shown in Figures 13 to 16 providing an inline cable jointing arrangement; Figure 18 is a scrap section view showing an arrangement for locking parts of a junction box in assembled position; Figure 19 is a part sectional view, similar to Figure 18; Figures 20 and 21 are views similar to Figure 19 showing parts in various positions during disengagement of the interlocking parts; Figure 22 is an exploded perspective view of the interlocking parts; Figure 23 is a perspective view of an alternative key for use in disengaging the interlocking parts; Figure 24 is a view similar to Figure 20 showing the alternative key in operational use.

Figures 25 and 26 are sectional view on the line XXVI XXVI of Figure 24 showing a method of actuating the alternative key to disengage the interlocking parts; and Figure 27 is a plan view, with part broken away and in-section of an end portion of the junction box.

As can be seen in Figures 1 and 2 two three-core cables 2 and 4 have their individual cores 6A, 6B and 6C connected to cores 8A, 8B and 8C respectively within terminal tubes 10A, 10B and 10C which are insulatingly embedded within a conventional multi-connector block 12.

The bared ends of the manner. The connector block 12 is formed with slots 16 which are arranged to locate around upstanding lugs 18 moulded in one with, and extending upwardly from a base 20 of a junction box 22.

As can be seen clearly in Figures 1 and 2, the ingoing and outgoing cables 2 and 4 enter the box 22 through a common entry 24.

In use, the operation of inserting and clamping the individual cores of the cables within their respective terminals can be effected externally of the junction box 22 and thus without difficulty. The connected connector block 12 is then located around the lugs 18 and the cables laid within the entry 24. A lid 26 is finally placed over the junction box, lips 28 on the lid overlapping upstanding walls 30 of the base member 20.

The junction box may be screwed to the wall or floor of a building utilising holes 32 provided in the base 20 for that purpose.

In the embodiment shown in Figures 3, 4 and 5 the junction box 2A has an entry and exit section 24A somewhat smaller in section than that of the first embodiment, the entry part and the main box part being interconnected by a tapered part 34. Otherwise, the components of the junction box assembly are similar to those seen in Figures 1 and 2, e.g. the connector block 12, terminals 10A, 10B and 10C, walls 30, base 22 with lugs 18, cables 2 and 4, and cover 26 with its lips 28.

In the embodiment shown in Figure 6 the components of the junction box are similar in most respects to those of the embodiment of Figures 3, 4 and 5 with the exception of the construction of the lid 26A which does not have the lips 28 as in the earlier embodiment. Instead, the lid 26A is attached to the main body of the box by a flexible hinge 34 and the peripheral- edges of the lid are formed with channels 36 which, when the box is in its closed position, engage with the upper portion of the upstanding walls 30A of the main body. Similar reference numerals are used for parts which correspond with those parts of Figures 3, 4 and 5.

The junction boxes so far described relate to those uses where the cables enter into and exit from a comnon port at one end of the box.

However, it sometimes occurs that it is desirable that the cables exit from an end of the box disposed opposite the entry port. This is termed a "strait through" type of connection and such a junction box and connector is seen in Figure 7.

In that embodiment the box 22 can be likened to a double-ended version of that seen in Figures 3, 4 and 5. The central portion of the box is formed with upstanding lugs 18 as in the earlier arrangements and the foremost part is tapered at 34 towards an entry port 24A. Rearwardly of the central portion of the box is a further tapered portion 35 leading towards an exit port 25A.

Thus, in use the cores 6A, 6B and 6C from the ingoing cable 2 are interconnected to their respective cores 8A, 8B and 8C by the connector blocks lOA, 1OB and lOC, these latter cores leading rearwardly into the cable 4 and out of the box via the exit port 25A. A lid is fitted over the box 22 after the connector block with the cores attached has been located with respect to the locating lugs 18, the lips fitting outside the upstanding walls 30 of the main body.

In order to enclose and seal the assembled box, in two or more places on the walls are formed recesses 40 and corresponding extensions 42 are formed on the lips 28 of the lid, as seen clearly in Figure 8. The slight spring in the material of the lid enables the extensions to ride over the top of the walls 30'until they snap into recesses 40.

In a further embodiment shown in Figures 9, 10, 11 and 12 a box 22 is constructed differently from the previous arrangements. Thus, a main body portion 50 has a forwardly extending portion 52 leading to an entry port 54, locating lugs 18 being provided as before, and a rearward portion 56 having a tapered portion 58 leading to an exit port 60. The two main portions 50 and 56 are interconnected by an intermediate portion 61 hingedly connected to both portions 50 and 56.

As seen clearly in Figures 9 and 11 the rear peripheral portion of the base 62 is formed with a channel 64 and the front portion of the same base has an upstanding wall 66. Conversely, the front peripheral portion of the base portion 68 is formed with a channel 70 and the rear portion of that same base has a downwardly depending wall'72; Both forward and rearward edges of the intermediate portion 61 are formed with channels 63.

In use the rearmost base portion and the intermediate portion 61 are folded upwardly and forwardly to adopt the position shown in chain lines in Figure 10 whereby the wall 66 engages the channel 70 and the wall 72 engages the channel 64. The intermediate portion 61 thus forms a closed rear end to a single entry type junction box.

A convenient snap-fitting arrangement is shown in Figure 12 whereby lugs 74 formed on the walls 66 and 72 engage within recesses 76 formed on the inside of lips 78 depending from the base portion 68. Similarly (but not shown in the drawings) lugs formed on the wall 72 engage recesses formed on upwardly depending lips on the base portion 62.

Although snap-on fastening devices are illustrated in- Figures 8 and 12 in order to retain the lids on to the side walls of the junction boxes, several alternative forms of fastening may be provided.

For example, readily available so-called cable ties may be passed around an assembled junction box and secured in well-known manner. Alternatively, part of a cable tie may be welded or otherwise fastened to the base part of the assembly and a co-operating part of the tie similarly secured to the lid part. A further known system including an upstanding post formed with a barb at its top portion which is made to pass through a co-operating slot in part of the lid may also be utilised.

In the embodiments shown in Figures 13 to 18 an arrangement is provided which allows one design of junction box to be used in a "single-entry" manner as previously described with reference to Figures 9 and 10, but which, by simply superimposing a second identical component over the top transforms the composite box into a "straight-through" type of connection box. In this way the user can keep a stock of junction box components which may be used according to needs, whether in the "single entry" or the "straight through" mode.

As clearly seen in Figures 13 to 16, this type of junction box is in some respects similar to that seen in Figures 9 and 10, having a main body section 80, formed with locating lugs 82, and having a forwardly extending portion 84 leading to an entry and/or exit port 86. A rearward body section 81 has a portion 88 leading to a further entry and/or exit port 90, the two main body portions 80 and 81 being interconnected by an intermediate portion 92 hingedly connected to both portions 80 and 81.

Depending upwardly from the base 94 at its front edge is a wall 96 and a further wall 98 depends from the front edge of the base 100 of the portion 84. A further wall 102 depends upwardly from the front edge of the base 104 of the port 86. A second upstanding wall 106 is formed adjacent the wall 102 to provide a locating slot 108 therebetween, the purpose of which will become apparent later.

Somewh t similar walls 96A, 98A and 102A are provided towards the rear edge of the bases 94, 100 and 104, the wall' 96A being shorter in length than the walls 98A and 102A. The walls 96A, s 98A and 102A are inset a small distance from the edge of the bases as seen clearly in at least Figure 13.

The intermediate hinged portion 92 is formed with an orthogonal wall 110 inset a small distance from the rearward edge in the same way as the walls 96A, 98A and 102A.

The rearward body portion 81 is formed with upstanding walls 11?, 114 and 116 at its rearmost edge with a further wall 118 adjacent the wall 116 to provide a locating slot 120. Further walls 122, 124 and 126 are provided inset somewhat from the forward edge of the bases 128, 130 and 132 as seen clearly in Figures 13 and 14.

Wnen it is to be used as a "single-entry" junction box, the cables are first attached to the conventional connector strip as before which is then located with respect to the location lugs 82. The intermediate portion is then folded upwardly about its hinge with the base 94 whereby the portion 92 closes the space between the main body portions 80 and 81 and the orthogonal wall 110 locates against the edge of the short wall 96A as seen in Figure 15.

Further downward hinging of the rear portion 81 causes the walls 112, 114 and 116 to locate outside the walls 96A, 98A and 102A. At the same time walls 122, 124 and 126 are caused to locate inside the walls 96, 98 and 102. The wall 102A fits within the slot 120 at the rear of the main body andsimilarly thewall 126 fits within the slot 108 at the front of the main body.

The same component can be used, in duplicate, to provide a "straight-through" junction box by simply keeping the lower member in its extended position as seen in Figures 13 and 14 and then taking an identical component and placing it in an inverted state, on the top of the lower member. The junction box thus adopts the configuration seen in Figure 17 wherein, the walls 112, 114 and 116 overlap the walls 122, 124, and 126 and the walls 96, 98 and 102 overlap the walls 110, 96A, 98 and 102A. The walls 102A and 126 of the inverted covering component fit smoothly in the slots 108 and 120 respectively of the lower component and the walls 102A and 126 of the lower component fit smoothly in the slots 120 and 108 respectively of the upper component providing a rigid box-like structure.

A locking arrangement for retaining the upper and the lower components in assembled condition is shown in Figure 18 and in an upstanding wall 102 are provided three detents 140 which engage a sprag 142 formed on the wall 102A of the upper component of the assembly. Three detents are provided in order to allow a variety of thickness of cable to be accomodated within the entry and exit ports; the detents and sprags are provided in respect of all the wall and slot connections at both entry and exit ports.

Figure 1 shows a junction box provided with holes 32 through which screws may be passed to secure-the box to a surface. Similar arrangements (not shown) may be provided in any of the alternative embodiments or one or more iugs formed on the outer-surfaces of the main body may have similar fixing holes provided.

Various cable clamping arrangements already known in the art, may also be provided within the junction box to prevent accidental pulling out of the cables from the connector block.

The main body and the cover of the junction box is preferably made by an injection moulding process from a suitable plastics material which accords to Building and Fire Safety Regulations.

Referring to Figures 19 to 22, the end portion of a junction box comprises a base 104 and vertical walls 102, 106 and 102A depend upwardly from that base. Thus, a locating slot 108 is formed between the walls 102 and 106.

The upper wall 104 is formed with downwardly depending vertical walls 116, 118 and 126, the walls 116 and 118 defining a slot 120 as seen clearly in Figure 22.

The walls 102 and 116 are formed with detents 140 and the downwardly depending wall 126 and upwardly depending wall 102A have sprags 142 which engage within the detents 140 when the junction box is in its closed position.

To disengage the interlocking parts of the closed junction box a tool T is used. For this purpose the upper wall portion 104 of the cover is formed with holes 150 which are aligned with spaces 152 and 152A formed in the walls 102 and 102A respectively (see particularly Figure 22) As seen in Figures 20 and 21, in order to disengage the interlocking parts of the junction box, the stem T1 of the tool T is inserted through the hole 150 and into the space 152 or 152A and is then rocked to cause the lower end portion P to press onto the inner face of the wall 102 or 102A and flex that wall outwardly until the relevant detents 140 are freed from engagement with the sprags 142.

The upper portion of the junction box may the be raised to provide access to the inside of the box and to the cables therein. The tool T may comprise a conventional electrical screw driver.

An alternative system is shown in Figures 23 to 27, utilising a key K seen in Figure 23. This key has a stem K1 at the lower end of which is formed a cam lobe K2. A handle K3 is provided at the upper end portion of the stem, and the stem extends a short distance below the lobe K2 to locate within a recess 154 formed in the base 104 (see Figure 24). Elongate openings 156 are formed in the upper wall 104 and in the walls 102A and 126.

In use, the stem K1 and the lobe K2 are inserted through the holes 150 spaces 156 and passed downwardly to locate the lower end of the stem in the recess 154, the lobe K2 being in position parallel with the walls 102, 102A. The key K is then rotated about its axis by means of the handle K3 to cause the lobe to exert pressure on the wall and so free the engagement of the detent 140 with the sprag 142 when the upper portion of the junction box may be raised to allow access to its interior.

Other forms of tools or keys may be provided and the two embodiments described and illustrated are intended merely as just two examples.

Claims (8)

1. An electrical junction box comprising a housing which can contain a length of multi-connector strip, can allow exit and egress of electrical cables, which cables are to be electrically connected by the multi-connector strip, and can be closed.

2. An electrical junction box according to claim 1, wherein the housing includes means for locating a length of multi-connector strip.

3. An electrical junction box according to claim 1 or claim 2, wherein the housing comprises a main body and a cover member.

4. An electrical junction box according to claim 3, wherein the cover member is separate to the main body.

5. An electrical junction box according to claim 3, wherein the cover member is coupled to the main body member by an integral hinge.

6. An electrical junction box according to any one of claims 3 to 5, wherein ties or clips are provided to secure the cover member to the main body.

7. An electrical junction box according to claim 4, wherein the cover member is identical to the main body and is interengagable therewith when in an inverted orientation.

8. An electrical junction box substantially as hereinbefore described and illustrated with reference to the accompanying drawings.

8. An electrical junction box according to any one of claims 3 to 7, wherein the main body and the cover are provided with interengaging parts.

9. An electrical junction box according to claim 8 wherein release of the interengaged parts can only be effected by use of a tool.

10. An electrical junction box substantially as hereinbefore described and illustrated with reference to the accompanying drawings.

Amendments to the claims have been filed as foNows 1. An electrical junction box comprising a housing which can contain a length of multi-connector strip, can allow exit and egress of electrical cables, which cables are to be electrically connected by the multi-connector strip, and can be closed wherein the housing incorporates an integral hinge whereby a rear base portion of the housing can be folded over from an open position to a closed position in which it overlies a front base portion and cooperating detents and sprags are provided on walls of the base portions which interengage in the closed position to enable an entry and exit port of the housing to accommodate a variety of thickness of cable.

2. An electrical junction box according to claim 1, wherein the housing includes means for locating a length of multi-connector strip.

3. An electrical junction box according to claim 1 or claim 2, wherein the housing incudes a further integral hinge, the hinge and further hinge joining an intermediate portion of the housing to the rear base portion and the front base portion respectively.

4. An electrical junction box according to any one of claims 1 to 3, wherein ties or clips are additionally provided to secure the housing in the closed position.

5. An electrical junction box according to any one of claims 1 to 4, wherein the housing in the open position can interengage with an identical further housing provided in an inverted orientation to form a closed straight through junction box.

6. An electrical junction box according to any one of claims 1 to 5, wherein the detents are provided in a slot between two walls.

7. An electrical junction box according to claim 6, wherein release of the sprags from the detents can only be effected by use of a tool.