GB2238184A

GB2238184A - Mounting box for electrical terminal

Info

Publication number: GB2238184A
Application number: GB8925875A
Authority: GB
Inventors: Cecil Maurice Appleby
Original assignee: H & L Appleby Ltd
Current assignee: H & L Appleby Ltd
Priority date: 1989-11-15
Filing date: 1989-11-15
Publication date: 1991-05-22
Anticipated expiration: 2009-11-15
Also published as: GB8925875D0; GB2238184B

Abstract

A mounting box comprises a body having first and second interengageable parts, a terminal to which a conductor is in use connected, a receiving formation to receive the terminal when the first and second parts are at least not fully interengaged, the terminal being prevented from being disengaged from the receiving formation when the first and second parts are fully inter-engaged, whereby the terminal may be retained in the receiving formation without the need for any fastenings or the like. As shown, a two-part box (12, 10) with a lid (17) traps a terminal (40) in opposing slots (36) of removable columns (33, 34), the terminal ears (41, 42) of which may snap-engage the slots. Alternatively, the box comprises a base and lid alone. The box supports a rail (30) and recesses (28) for supporting circuit breakers or other accessories and provides supports (50, 52) or (56, 57) for seals (54, 53). The terminal (40) screw interconnects plural neutral or earth leads to the main lead, the live lead feeding the circuit breakers. <IMAGE>

Description

Description of Invention This invention relates to a mounting box for example, for an electrical accessory such as a circuit breaker.

Such mounting boxes are known generally in which the or each circuit breaker is wired up to a live lead of a power supply and to a live line of a circuit, to distribute current to the or each circuit protected by the circuit breaker or breakers.

Means need to be provided conveniently to enable the neutral and/or earth line of each circuit to be connected respectively to a neutral lead of the power supply, or to earth.

According to the invention we provide a mounting box comprising a body having first and second interengageable parts, a terminal to which a conductor is in use connected, a receiving formation to receive the terminal when the first and second parts are at least not fully interengaged, the terminal being prevented from being disengaged from the receiving formation when the first and second parts are fully inter-engaged.

Thus the terminal may be retained in the receiving formation without the need for any fastenings or the like.

If desired though, the termincl may be snap interengageable with the receiving formation.

The first and second parts of the box may together provide a base and the base may present an opening which may be closed by a lid.

Alternatively, the first part may provide a base which presents an opening and the second part may provide a lid to close the opening which lid may be separable from the base or hinged thereto in which latter case the base and lid may be only fully interengaged when the lid is fully closed.

In each case, the first part may have a bottom surface and one or more side walls which extend from the bottom surface to a position of interconnection with the second part.

The receiving formation for the terminal may be provided by one or more pillars which are attached to the first part and extend towards a position of interconnection with the second part. For example the pillar or pillars may be connected to the inside of the bottom surface of the first part. The pillars may each extend in a first direction from the bottom surface of the box in the corners to positions near to the position of interengagement of the first and second parts.

To facilitate this, the bottom of the box on the inside may be provided with a recess in which a fastening may be received to secure the pillar to the bottom surface.

The inside of the bottom surface of the box may have other recesses to receive fastenings to enable an electrical accessory for example such as a circuit breaker to be mounted in the box.

Preferably the box is of generally cuboid configuration and a pair of pillars are provided in at least two adjacent corners of the box. Each of the pillars may have a slot which slots together provide a receiving formation for the terminal which may be received in engagement with the slots and extend between the pillars.

The slots may open in a second direction opposite to the first direction towards the bottom surface of the box.

When the first and second parts are fully interengaged, the terminal may be prevented from becoming disengaged from either of the slots. For example, the second body part may have ct least one formation which contacts, or lies closely adjacent to, the terminal over the top of the receiving formation to prevent the terminal becoming disengaged from the receiving formation when the first and second parts are fully interengaged.

Preferably the first and second parts interengage at a plane of interengagement, and are secured together by securing means such as fixings which may be provided in each corner of the box or intermediate the corners as desired.

Preferably means are provided to enable a seal to be provided between the first and second parts, to indicate when the first and second parts have been separated.

Thus for example, a fixing of the box may have an opening which may be aligned with an opening of the first or second part, to receive a seal so that in the event that the first and second parts are separated, the fixing has to be removed, thereby breaking the seal.

If desired, when the box has a lid, openings may be provided in the lid and in the base, to receive a seal when the lid is fully closed, which seal becomes broken in the event that the lid is subsequently opened.

Such seals are commonly applied by the electricity supply authorities in circumstances where it is desired to deter tampering with the contents of the mounting box.

The means which mount the electrical accessory, where provided, may comprise a rail secured to the inside bottom surface of the box, the rail being adapted to receive the electrical accessory.

A plurality of electrical accessories may be received by the rail if desired.

The electrical accessory, or each electrical accessory may comprise a circuit breaker to which a live lead of a power supply is, in use, connected, and to which a live line of a circuit is connected. The terminal may comprise means to connect a neutral lead of the power supply and a neutral line of the or each circuit thereto.

Alternatively, the terminal may comprise means to connect an earth lead and an earth line of the or each circuit thereto.

Preferably, two separate terminals are mounted in the box, one for the neutral lead and neutral line or lines, and the other to enable an earth line of the or each circuit to be connected to earth.

To facilitate this, a further receiving formation may be provided for the second'terminal, which may thus be mounted in the same manner as the first mentioned terminal.

If desired the terminals may be colour coded or otherwise marked clearly to indicate to an electrician which terminal is for neutral, and which terminal is for earth.

The two terminals may be provided at opposite ends of the box where the box is rectangular.

The invention will now be described with reference to the accompanying drawing which is an exploded perspective view partially cut away of a mounting box in accordance with the invention.

Referring to the drawing, a mounting box 10 comprises a base II comprising a first part 12 and a second part 13 which are adapted to be interengaged and secured together by four fixings indicated at I 5, one in each corner of the generally cuboid box 10.

The second part 13 has an opening ló which is closeable by a lid 17 which is hinged for opening about an axis A, and is retained closed by snap interengaging formations 18 which co-operate with corresponding formations 19 of the second part.

The fixings 15 are entrapped with respect to the second part 13 so that they cannot be lost when undone, and openings 20 of the first part which are threaded internally to receive the fixings 15 are through openings and may receive screws to enable the box 10 to be mounted on a wall for example.

The first part 12 has a bottom surface 21 from which extends four side walls 22,23,24, and 25 which extend upwardly to rim 26 contained in a pldne where the first 12, and second 13, parts of the base 11 interengage.

The inside of the bottom surface 21 of the box, is provided with a plurality of recesses 28 arranged in an array, which recesses are adapted to receive self tapping screws of the correct size to enable articles to be secured to the bottom surface 21 of the box.

In the example shown, a rail 30 is secured to the bottom surface 21 of the box 10 by a pair of fastenings 31 (only one of which is seen) and electrical accessories comprising a pair of circuit breakers 32 are received by the rail 30 so as to be mounted within the box 10. The circuit breakers 32 are in use intended to provide electrical continuity between a live lead of a power supply (not shown) and a live line of a respective circuit which is protected by a respective one of the circuit breakers 32.

in two adjacent corners of the box 10, there are provided a pair of pillars 33 and 34, pillar 34 being shown in its, in use, position. The pillars 33,34, are secured in the corners of the box by fastenings 35 which are received in appropriate recesses 28' in the bottom of the box 10. Each of the pillars 33,34, provides a pair of downwardly openings slots 36,36'.

A terminal 40 is of generally elongate configuration and has a pair of outwardly extending ears 41,42, at each of its opposite ends, ear 41 being arranged in use to be received in one of the slots 36 of the pillar 33, and the ear 42 being adapted in use to be received in one of the slots 36 of the pillar 34 so as to extend between the pillars 33,34, as indicated in dotted lines in the drawing.

The terminal 40 has a plurality of openings 44 each of which is able to receive a conductor, each of the conductors being thereby connected to one another. As is conventional with an electrical terminal, screws 45 may be screwed through the openings 44 so as to entrap the conductors within the respective openings 44.

Thus the terminal 40 may be used to receive a neutral lead of a power supply, and each neutral line of the respective circuits protected by the circuit breakers 32 so as conveniently to connect the neutral conductors together.

The ears 41 and 42 of the terminal 40 may be snap interengagable with the respective slots 36 of the pillars 33,34, although alternatively the ears 41,42, may be loosely received within the slots 36 as desired.

Thus the slots 36 together provide a receiving formation to receive the terminal 40.

It can be seen that the pillars 33 and 34 extend upwardly to a position adjacent the plane of the rim 26 where the first 12, and second 13, parts of the base II interengage. When the terminal 40 is received by the pillars 33,34, the ears 41 and 42 are at a position such that when the second part 13 of the box 10 is interengaged with the first part 12, the downwardly facing edge 45,44, of the second part 13 in the corners of the box 10 either contact, or lie very closely to, the top surfaces of the ears 41 and 42, so as to prevent terminal 40 becoming disengaged from the receiving formation provided by the slots 36.

If desired, a terminal such as terminal 40 may be mounted by respective pillars at the opposite end of the box, or along one of the other two sides. It can be seen that each pillar has a second slot 36a which may be used to receive such ear of a further terminal 40 if desired.

Preferably the box 10 is moulded in a plastics material so as to be self insulating although if desired, the box 10 may be made out of other materials with suitable insulation provided.

As described, the base 11 of the box 10 comprises the first and second parts 12 and 13, which when interengaged prevent the terminal 40 becoming disengaged from the receiving formation provided by slots 36. In an alternative embodiment, the box 10 may simply comprise a base having an opening such as opening 16, and a lid, and the lid when fully closed over the opening i.e. fully interengaged with the base, prevents the terminal 40 becoming disengaged from its receiving formation. In this event, the lid may be hinged to the base in which case by "fully inter-engaged" we mean that the lid must be fully closed with respect to the base.

It can be seen that in figure 1, when the lid 17 is open, access can be gained to the circuit breakers 32 within the box 10 through the opening 16.

If desired, an electrical accessory other than a circuit breaker 32 may be mounted within the box 10, and need not be mounted using a rail such as rail 30 shown. For example, an electrical accessory may be mounted directly on the bottom surface 21 of the box 10 using one or more of the recesses 28 provided for that purpose.

By providing an array of recesses 20 as shown, the position of an electrical accessory within the box 10 can be freely chosen so as to mount the electrical accessory in any desired position.

At least one of the fixings 15 preferably at least two of the fixings 15, has an opening 50, which when the fixing 15 is screwed into its opening 20 in the second part 13, is aligned with an opening 51 of the body part 13. The opening 50 communicates with a top opening 52 which provides a slot for a screwdriver bit, to enable the fixing 1 5 to be screwed and unscrewed. A tail 53 of a seal 54 can be inserted through the aligned openings 50,52, and the seal crimped to the tail 53. Thus it is necessary to break the seal subsequently to separate the body parts 12,13.

Alternatively or additionally, the lid 17 may have an opening 56, and the body part 13 may have an opening 57, through which openings 56,57, a tail 53 of a seal 54 can be threaded, again to enable a seal to be achieved between the lid 17 and base 11 which would need to be broken to permit the lid 17 to open.

In this way the box 10 can be sealed against unsuthorised tampering.

Other modifications may be made without departing from the scope of the invention. For example, the pillars 33,34, need not be secured to the bottom surface 21 of the box 10, but may be secured to a side wall 23-26 or side walls of the box if desired. The arrangement for interengaging the first and second parts 12 and 13 may be different to that shown, although in each case, preferably the second port of the box 10 has a formation such as formation 44 which when the terminal 40 is received in its receiving formation, and the first and second parts are fully interengaged, prevents the terminal 40 being disengaged therefrom.

The features disclosed in the foregoing description or the accompanying drawing, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A mounting box comprising a body having first and second interengageable parts, a terminal to which a conductor is in use connected, a receiving formation to receive the terminal when the first and second parts are at least not fully interengaged, the terminal being prevented from being disengaged from the receiving formation when the first and second parts are fully interengaged.

2. A box according to claim I wherein the terminal is snap interengogeable with the receiving formation.

3. A box according to claim I or claim 2 wherein the first and second parts of the box together provide a base, the base presenting an opening which is closable by a lid.

4. A box according to claim I or claim 2 wherein the first part provides a base which presents an opening and the second part provides a lid to close the opening.

5. A box according to claim 3 or claim 4 wherein the lid is separable from the base.

6. A box according to claim 3 or claim 4 wherein the lid is hinged to the base and the lid is only fully interengaged with the base when the lid is fully closed.

7. A box according to any one of the preceding claims wherein the first part has a bottom surface and one or more side walls which extend from the bottom surface to a position of interengagement with the second part.

8. A box according to claim 7 wherein the receiving formation for the terminal is provided by one or more pillars which are attached to the first part and extend towards the position of interengogement with the second part.

9. A box according to claim 8 wherein the pillar or each pillar is connected to the inside of the bottom surface of the first part.

10. A box according to claim 8 or claim 9 comprising a plurality of side walls, the pillars each extending in a first direction from the bottom surface of the box in corner thereof to positions near to the position of interengagement of the first and second parts.

11. A box according to claim 9 or claim 10 wherein the bottom of the box on the inside is provided with a recess in which a fastener is receivable to secure the pillar to the bottom surface.

12. A box according to claim 11 wherein the inside of the bottom surface of the box has other recesses to receive fasteners for means which mount an electrical accessory.

1 3. A box according to any one of claims 8 to 12 wherein the box is of generally cuboid configuration and a pair of pillars are provided in at least two adjacent corners of the box.

14. A box according to claim 13 wherein each of the pillars has a slot, which slots together provide a receiving formation for the terminal which, in use, is received in engagement with the slots and extends between the pillars.

IS. A box according to claim 14 wherein the slots extend towards the bottom surface of the box and when the first and second parts are fully interengaged, the terminal is prevented from becoming disengaged from either of the slots by at least one formation of the second body part which contacts, or lies closely adjacent to, the terminal above the receiving formation.

16. A box according to any one of the preceding claims wherein the first and second parts interengage at a plane of interengagement, and are secured together by securing means which are provided in each corner of the box or intermediate the corners.

17. A box according to claim 16 wherein means are provided to enable a seal to be provided between the first and second parts, to indicate when the first and second parts have been separated.

18. A box according to claim 17 wherein a fixing of the box has an opening which is capable of being aligned with an opening of the first or second part, to receive a seal so that in the event that the fixing is removed such as to enable the first and second parts to be separated, the seal is broken.

19. A box according to any one of claims 3 to 18 where appendant to claim 3 or claim 4 wherein openings are provided in the lid and in the base, to receive a seal when the lid is fully closed, which seal is broken in the event that the lid is subsequently opened.

20. A box according to any one of claims 12 to 19 where appendant to claim 12 wherein the means which mount the electrical accessory, comprise a rail secured to the inside bottom surface of the box by the fasteners, the roil being adapted to receive the electrical accessory.

21. A box according to claim 20 wherein a plurality of electrical accessories are received by the rail.

22. A box according to claim 20 or claim 21 wherein the electrical accessory, or each electrical accessory comprises a circuit breaker to which a live lead of a power supply is, in use, connected, and to which a live line of a circuit is connected, the terminal comprising either means to connect a neutral conductor of the power supply and a neutral conductor of the or each circuit thereto, or means to connect an earth conductor and an earth conductor of the or each circuit thereto.

23. A box according to claim 22 wherein two separate terminals are mounted in the box, one for the neutral conductors and the other to enable earth conductors of the or each circuit to be connected to earth.

24. A box according to claim 23 wherein a further receiving formation is provided for the second terminal, which is mounted in the same manner as the first mentioned terminal.

25. A box according to claim 23 or claim 24 wherein the terminals are colour coded or otherwise marked clearly to indicate to an electrician which terminal is for neutral, and which terminal is for earth.

26. A box according to any one of claims 23 to 26 wherein the two terminals are provided at opposite ends of the box where the box is cuboid.

27. A mounting box substantially as hereinbefore described with reference to and as shown in the accompanying drawings.