GB2159005A - Electrical accessory closure - Google Patents

Abstract

An electrical accessory eg a conduit box has an enclosure (1) and a closure lid (2) held in position by securing elements eg screws passed through lid apertures (5) engaging in apertures formed in pillars (4). The lid is provided with projections (8) arranged so that when the lid is placed randomly on the enclosure with the lid apertures out of alignment with the pillar apertures, relative rotation of the lid and enclosure engages the projections with the pillars and thereby effects alignment of said lid and pillar apertures to permit passage of said securing elements. <IMAGE>

Description

SPECIFICATION Electrical accessory This invention relates to an electrical accessory of the kind which includes an enclosure and a lid heid in position thereon by at least one securing element, such as a screw, which passes through an aperture in the lid into fixing engagement with a fixing formation, such as a pillar, on a wall of the enclosure.The invention is particularly applicable to an electrical conduit box having openings to receive conduits and providing access to electrical wires housed within the conduits.

In conventional conduit boxes, the lid is commonly in the form of a flat plate which is difficultto position quickly with its fixing aperture orapertures in alignmentwith the respective corresponding fixing formation ofthe enclosure. Moreover, present day conduit boxes and other similar accessories are made increasingly from plastics materials, predominently by injection moulding, and it has been found to be difficult, using such techniques, to form a flat lid with a sufficiently high standard offinish, due primarily to the formation of spruce and other imperfections.

An object of the invention is to provide an improved electrical accessory in which the aforementioned problems are alleviated or avoided.

According to the present invention, the lid of an electrical accessory ofthe aforesaid kind is provided on its normally inner surface with at least one locating projection and the enclosure is provided with a locating formation, said projection and formation being arranged in relation to said lid aperture such that, when the lid is placed on the enclosure, with said lid aperture out of alignment with the fixing formation, rotation ofthe lid brings said projection and formation into engagement, thereby bringing the lid aperture and fixing formation into alignmentto permitthe passage of a securing elementthroughthe lid aperture into the fixing formation.

In one convenient arrangement, the lid is provided with at least one pair of projections spaced so asto be capable of closely embracing the locating formation, surfaces of each projection opposed to those which engage the locating formation being chamfered and the arrangement being such that, with the projections disengaged from the locating formation, said rotation ofthe lid to bring one ofthe projections into engagement with the locating formation causes said one projection to ride up overthe locating formation and become positioned at the other side of the latter, thereby bringing the projections into embracing engagementwith the locating formation and the lid aperture into alignment with the fixing formation for the passage of a securing element through the lid aperture into the fixing formation.

Preferably, the projections are positioned respectively at eitherside of said lid aperture and the fixing formation acts also as the locating formation.

The normally underside of the lid is provided with a circular rim dimensioned to fit closely within a circular mouth ofthe enclosure so asto locate the lid in a desired position relativetotheenclosure,the rim being interrupted by a gap delimited by the projections.

When the enclosure is provided with a pair of opposed internal fixing formations, it can be convenientto provide a further gap in the rim opposite to the first gap, said further gap receiving the fixing formation opposed to that engaged by the projections in orderto provide additional location for the lid.

The invention will now be described, by way of example,with reference to the accompanying drawings in which, Figure 1 is an exploded perspective view of one form of the electrical accessory of the invention in the form of a conduit box and, Figure 2 is a sectional view ofthe accessory of Figure 1.

The drawings illustrate the accessory of the invention intheform of a conduit box having a generally circular body 1 forming an open-mouthed enclosure, the mouth being closed, in use, by a lid 2. The body 1 is provided with a number of inlets3forthe reception of conduits (not shown). In the example illustrated, the body has one pair of opposed inlet3 and a further inlet 3 at right angles to the aforesaid pair, effectively forming a T-configuration. It will be understood, however, that any convenient arrangement of inlets 3 may be provided, according to the requirements of use.

The body 1 is provided internally with a pair of fixing formations in the form of pillars 4 having internally threaded openings 4A capable of receiving fixing screws 4B (Figure 2) passed through corresponding holes 5 the lid 2.

The normally underside ofthe lid 2 has a peripheral projecting rim 6 arranged to fit closely within the mouth ofthe body 1 in orderto locate the lid radially.

The rim 6 is interrupted to form a gap 7 which is delimited by a pair of projections 8, the gap 7 being wide enough to permittheprojections8to embrace closely one ofthe pillars 4. The rim 6 is further interrupted, at a location diametrically opposed to the gap 7, by a further gap 9 having a width corresponding to that ofthe gap 7. The lid 2 can thus be securely held against rotation by one of the projections 4fitting within the gap 7 and the otherwithin the gap 9.

Each ofthe projections 8 is provided with a chamfered external edge portion 8A, such chamfered edge portions being very advantageous in facilitating alignmentoftheholes5withthethreaded openings 4A in the pillars 4 priorto insertion ofthefixing screws 4B.

The lid is normally placed in position on the body 1 with the rim 6 engaged within the mouth ofthe body.

If, as would normally be the case, the projections 8 are not in embracing relationship with one of the pillars 4, the lid may be rotated to bring one ofthe projections The claims were filed later than the date within the period prescribed by Rule 25(1) of the Patents Rules 1982.

into engagement with one of the pillars. Continued rotation then causes a camping action to occur between the appropriate surface 8A ofthe projection 8 and the pillar, causing the lid to ride up over the pillar.

This results in the projection 8 passing over the top of the pillar4 and dropping into position at the far side of the pillarto bring the projections into embracing relationship with the pillar. At the same time, the other pillar4will become engaged within the gap 9. It will be seen thatthis action automatically brings the holes 5 into alignment with the threaded openings 4A in the pillars, enabling rapid insertion of screws to fix the lid in position. The provision of the projections 8 with their chamfered surfaces 8A enablesthe lid to be brought rapidly into a correct position of use, irrespective ofthe position in which it is first placed over the mouth ofthe body.

An additional advantage ofthe projections 8 is that these may be used as the injection points during injection moulding ofthe lid 2, which means that residual sprue and other associated imperfections will occuratthe projections 8, from which they are easily removable, enabling the main surfaces of the lid to be formed with an excellent finish.

Although it is preferred to use the pillars 4 for locstion purposes, as well as for fixing, it will be understood that the or each location formation may alternatively be provided on the body separately from the fixing formations. The projections 8 would then no longer be at either side of a lid aperture 5 but disposed in reiaiior, to that aperture suon t when they re brought into embracing relationship with the location formation, the or each lid aperture 5 is aligned with a respective opening 4A.

In another alternative arrangement, only one pro ejection is provided on the jid for engagement with 2 locating formation on the body, these being arranged in relation to the id aperture such that abutment thereof occurs when said aperture is aligned with the fixing formation

Claims (7)

1. An electrical accessory comprising an enclosure and a lid held in position thereon by at least one securing elementwhich passes through an aperture in the lid into fixing engagement with a fixing formation, the id being provided on its normally inner surface with at least one locating projection and the enclosure is provided with a locating formation, said projection and formation being arranged in relation to said lid aperture such that, when the lid is placed on the enclosure, with said lid aperture out of alignment with the fixing formation, relative rotation between the lid and enclosure brings said projection and formation into engagement, thereby bringing the lid aperture and fixing formation into alignment to perm it the passage of a securing element th rough the lid aperture into the fixing formation.

2. An accessory according to Claim 1 wherein the lid is provided with at least one pair of projections spaced so asto be capable of closely embracing the locating formation, surfaces of each projection opposed to those which engage the locating formation being chamfered and the arrangement being such that, with the projections disengaged from the locat ingformation,said relative rotation to bring one ofthe projections into engagement with the locating forma tion causes said one projection to ride up overthe locating formation and become positioned at the other side of the latter, thereby bringing the projec tions into embracing engagement with the locating formation and the lid aperture into alignmentwith the fixing formation forthe passage of a securing element through the lid aperture into thefixing formation.

3. An accessory according to Claim 2 wherein the projections are positioned respectively at either side of said lid aperture.

4. An accessory according to any one of the preceding claims wherein the fixing formation acts also as the locating formation ofthe enclosure.

5. An accessory according to any one of the preceding claims wherein the normally underside of the lid is provided with a circular rim dimensioned to fit closely within a circular mouth of the enclosure so as to locate the lid in a desired position relative to the enclosure, the rim being interrupted by a gap delimited by the projections.

6. An accessory according to Claim 5 wherein the enclosure is provided with a pair of opposed internal fixing formations and the rim is provided with a further gap oppositetothefirstgap, saidfurthergap receiving the fixing formation opposed to that engaged by the projections in orderto provide additional location forthe lid.

7. An electrical accessory substantially as hereinbefore described with reference to the accompanying drawings.