GB2257850A - Casing for electrical connections. - Google Patents

Abstract

A casing for electrical apparatus comprises a pair of hollow body parts (10, 11) each of which has an edge (17, 18), the edges being contiguous when the parts are assembled together. Each edge is formed with first and second portions (23, 21) which are received in a rebated recess of a tubular connector element (24). The two body parts can be flexed apart to insert contents but are prevented from separating by the edge formations, the first portions (23) resisting separation of the body parts at least when they are partly separated, whilst the second portions (21) prevent lateral removal from the recess of the tubular connector element (24). The body parts (10, 11) may be moulded in one part, and later separated. <IMAGE>

Description

Title - Casings This invention relates to casings particularly, but not exclusively, for use in encasing electrical apparatus such as connections in power distribution systems.

It is known to produce casings for electrical connections in the form of a hollow plastics body in two components, wherein these components are initially produced side-by-side as an integral moulding. The structure is then re-heated along a line between the two components and is folded to bring those components into mutual contact. The resultant hollow body has the advantage that the two components can be flexed apart sufficiently to allow insertion of the electrical connection into the hollow, but thereafter are held together comparatively firmly. Thus, the need to hold the components together by other means (e.g.

manually) is avoided, both during insertion of the electrical connection and in subsequent sealing of the casing.

Casings of this type do however suffer from the disadvantage that they are bulky for transportation between the point of manufacture and the point of use, and for storage prior to use.

Even if transported or stored in the "unfolded" condition where several such items can be nested one within another, the area occupied by the casing is relatively large.

It is an object of the present invention to obviate or mitigate this problem.

According to the present invention, there is provided a casing comprising a hollow body formed in two parts, the parts having respective edges which are contiguous with one another when the parts are assembled together, and a connector element which extends at least partly along said edges and which receives said edges in a rebated recess therein, the edges having respective first portions which abut one another at least when the body parts are flexed apart to resist further flexing of the body parts, the edges also having respective second portions which prevent said edges from being withdrawn laterally from the rebated recess.

Preferably, each said edge is formed on a generally planar flange on the respective body part, the first portions of the edges are in face-to-face abutment at least when the body parts are flexed as aforesaid, and the second portions of the edges extend out of the planes of the flanges, respectively.

The first portions may be coplanar with the flanges or may extend slightly out of the planes of the flanges either towards or away from each other.

Advantageously, a plurality of first and second portions are provided on each edge, and these preferably alternate along the length of that edge.

Conveniently, the connector element is in the form of a split tube, for example of circular cross-section.

The invention will now be further described, by way of example only, with reference to the accompanying drawing, in which: Figure 1 is a perspective view showing a casing according to the present invention during an initial stage of its manufacture; Figure 2 is an enlarged scrap view in the direction of arrow A in Figure 1; Figure 3 is a perspective view showing the casing in a subsequent stage of its manufacture; Figure 4 is an enlarged scrap view in the direction of arrow B in Figure 3; Figure 5 is a perspective view, on a greatly enlarged scale of part of the casing as seen in Figure 3 partly broken away; and Figure 6 is a similar view to Figure 2, but showing an alternative embodiment of the invention.

Referring first to Figure 1, the illustrated casing comprises two components 10, 11 which are initially produced side-by-side as an integral plastics moulding. The component 10 is composed of a hollow body part 12 surrounded by a planar flange 13, while the component 11 is similarly composed of a hollow body part 14 and a flange 15. After the initial moulding operation, the components 10 and 11 are separated by cutting along a line 16: this produces respective edges 17 and 18 on the flanges 13 and 15, respectively. The components are then placed together with the flanges 13, 15 in face-to-face relation (see Figure 3) so that the edges 17, 18 are contiguous with one another and the two body parts 12, 14 co-operate to form a recess 19. This recess is destined to receive electrical apparatus such as a connection in a power distribution system.

As can be seen to advantage in Figure 2, in the initial moulding a series of formations 20 (only one shown) are produced so as to straddle the line 16. In the illustrated embodiment, these formations are of inverted v-shape and, after cutting along the edge 16, form respective projections 21 on the edges 17, 18 which extend out of the plane of the respective flange 13, 15 at an angle of about 45". The formations 20 alternate along the line 16 with flats 22 which, after cutting, form projections 23 on the edges 17, 18 which are coplanar with the respective flanges 13, 15. Each of the edges 17, 18 thus has angled and flat projections alternating along its length.

When the components 10, 11 are placed together as depicted in Figure 3, the angled projections 21 on edge 17 are aligned with the similar projections on edge 18, whilst the flat projections 23 on both edges are similarly aligned and are in face-to-face abutment. A connector element 24 is then slid lengthwise along the edges 17, 18 so that the projections 21, 23 are received in a rebated recess 25 therein - see Figure 5, wherein the element 24 is shown partly cut-away. In the illustrated embodiment, the element 24 is in the form of a split tube of circular crosssection.

Under these conditions, the inherent flexibility of the material from which they are made will allow the components 10, 11 to be flexed apart sufficiently to enable the casing to be placed over the electrical connection, with the connection being received within the recess 19. During this process, the projections 23 will be urged into close contact, thereby resisting further flexing movement of the components 10, 11 and also tending to return those components to their closed condition. At the same time, the angled projections 21 prevent the edges 17, 18 disengaging from the connector element 24.

Once the casing has been placed around the electrical connection, the space between the two components 10, 11 is filled with a cold curing compound for electrical insulation purposes. A strip of sealing tape (not shown) can be provided between the edges 17, 18to prevent leakage of the compound therefrom. The other edges, for example flanges 13, 15, can also be sealed with tape.

Either spring steel clips or a U-shaped plastics or metal extrusion can be used to hold the components during curing of the compound.

In actual usage, the casing can be transported and/or stored after the components 10, 11 have been separated and before they are assembled into their final configuration and before the connector element 24 is engaged with the edges 17, 18, the latter operations being readily performed on-site. During such transportation and/or storage, the components 10, 11 can be nested one within the other, along with components of a number of other similar casings, thereby minimising their overall bulk.

Although not shown, locating means can be provided on the components 10, 11 to prevent relative longitudinal slippage therebetween. For example, this locating means can be in the form of one or more tabs on the edge 17 which locate in corresponding recesses in the edge 18, and/or vice versa.

Additionally or alternatively, raised dimples can be provided on the flange 13 which engage with complimentary recesses or apertures in the flange 15, and/or vice versa.

In the above embodiment, the projections 23 have been described as being normally in face-to-face contact, i.e. even before the components 10, 11 are flexed to open up recess 19. However, it is possible that these projections 23 could be angled slightly so that they are normally out of contact with one another and brought into abutment only when the components 10, 11 have been flexed apart by a small amount. Conversely, the projections 23 can be angled in the reverse direction to provide a certain amount of pre-loading on the components 10, 11. It is also not necessary that the projections 21 and 23 on one flange are exactly aligned with their counterparts on the other flange: all that is necessary is that there is a degree of overlap between the respective projections 23.

The projections 21 can take many different forms other than that specifically described above, e.g. they could be part-circular in cross-sectional shape and/or could be formed by raised ribs.

The connector element 24 can similarly take many other forms, and could, for example, comprise a flat spine from whose edges a pair of integral arms extend at approximately the same angle as the projections 21. It is also possible for the connector element to extend only part way along the edges 17, 18 rather than along the whole length thereof as shown in the illustrated embodiment.

In the case where the initial moulding is produced by vacuum forming, it may be that the distance between the body portions 12, 14 is not sufficient to create an adequate thickness of material in the region of the formations 20 and the flats 22.

Under these conditions,.the area between the body portions can take the form depicted in Figure 6, i.e. wherein the parts which ultimately form the projections 21, 23 are separated by respective land portions 26, 27. Two cuts are then made at either end of these portions, as indicated at 28, with the land portions 26, 27 ultimately being discarded.

Although it is convenient for the components 10, 11 to be produced initially in integral side-by-side relation, this is not essential and the components could be formed individually instead, which may enable the two-component assembly method.

The invention has been described above with respect to a casing for electrical apparatus. However, it will be appreciated that there are many other fields in which a casing according to the invention can be utilised.

Claims (11)

Claims

1 A casing comprising a hollow body formed in two parts, the parts having respective edges which are contiguous with one another when the parts are assembled together, and a connector element which extends at least partly along said edges and which receives said edges in a rebated recess therein, the edges having respective first portions which abut one another at least when the body parts are flexed apart to resist further flexing of the body parts, the edges also having respective second portions which prevent said edges from being withdrawn laterally from the rebated recess.

2 A casing according to claim 1 wherein each said edge is formed on a generally planar flange on the respective body part, the first portions of the edges are in face-to-face abutment at least when the body parts are flexed as aforesaid, and the second portions of the edges extend out of the planes of the flanges.

3 A casing according to claim 2 wherein the first portions are coplanar with the flanges.

4 A casing according to claim 2 wherein the first portions extend slightly out of the plane of the flanges.

5 A casing according to claim 4 wherein the flanges extend out of said plane towards each other.

6 A casing according to claim 4 wherein the flanges extend out of said plane away from each other.

7 A casing according to any preceding claim wherein a plurality of first and second portions are provided on each edge.

8 A casing according to claim 7 wherein the first and second portions alternate along the length of the edge.

9 A casing according to any preceding claim wherein the connector element is in the form of a split tube.

10 A casing according to claim 9 wherein the tube is of circular cross-section.

11 A casing substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.