WO2006075131A1

WO2006075131A1 - An interconnection arrangement and related assemblies

Info

Publication number: WO2006075131A1
Application number: PCT/GB2006/000004
Authority: WO
Inventors: Christiaan Radelet; Ronnie Rosa Georges Liefsoens; Gwen Fouquet
Original assignee: Tyco Electronics Raychem Nv; Tyco Electronics Uk Ltd
Priority date: 2005-01-12
Filing date: 2006-01-05
Publication date: 2006-07-20
Also published as: GB0500508D0

Abstract

An interconnection arrangement (10) for two components (11, 12) having mutually engageable surfaces (13, 14) comprises a flexible strap (23) that is secured at respective locations (24) to the said components (11, 12). The positions of the said locations and the length of the strap therebetween causes the strap (23) to be: (i) taut when the said surfaces (13, 14) of the said components are mutually engaged; and (ii) slack when the said surfaces (13, 14) are disengaged from one another.

Description

AN INTERCONNECTION ARRANGEMENT AND RELATED ASSEMBLIES

This invention relates to an interconnection arrangement, and related assemblies. In particular the invention concerns an interconnection arrangement for interconnecting two components having mutually engageable surfaces.

The principles of the invention claimed herein are very broadly applicable, but one particular example of components having mutually engageable surfaces arises in a cable closure.

A typical design for cable closures comprises two hollow, elongate half shells having end walls one or both of which are perforated to permit cables to pass into the interior of the closure, to form "butt closures" or "in-line closures".

A cable closure typically is used to enclose a splice joining two or more cables together. The closure forms a sealed casing that protects the splice against ingress of contaminants such as dust and moisture, and provides mechanical (eg. impact/stress) protection.

Cable closures are manufactured in large numbers and installed in a great many locations. The need to enclose splices between the lengths of (data) cables or branch cables such as optical cables, cables having metallic conductors (eg. Copper pairs, Coaxial cables and electric power cables) has always existed. Telecom access networks in particular may require the use of large numbers (eg. several tens or hundreds) of the closures and associated terminals. Especially (but not exclusively) in these cases, it is desirable that in addition to providing reliable sealing, the closures 'are quick and simple to use, at the lowest possible cost.

To this end, it has become commonplace to hinge the half shells of the closure one to the other along one elongate edge of the resulting closure structure. This permits the laying of cables, extending lengthwise along the closure, into a lower half shell, without the need to cut the conductors or fibres of the cable. The other half shell may then be pivoted about the hinge to overlie the lower half shell and thereby permit completion of the closure. Since an installer may have to install many of the closures during the course of a day, it is desirable that the hinging arrangement is robust and reliable. At the same time, the need to mass-produce the closures prompts a need to reduce the cost and complexity of the components defining the hinge, while maintaining the structural strength and robustness of the hinge needed to obtain long term, reliable sealing/protection.

Several approaches to the hinging of mutually engageable components have, in the past, arisen in the cable closure art.

One example is shown in Figure I₅ in which the half shells 11, 12 of a cable closure 10 are shown in partly sectioned view in their closed position in which mutually engageable surfaces 13, 14 are shown in contact with one another to define a mating line 16.

The half shells 11, 12 are secured together by means of a conventional hinge 17 in which an alternating series of hinge eyes 18, extending along the length of the side of the cable closure 10 containing the mating line 16, are interconnected by a hinge pin 19 about the longitudinal axis of which hinging of the half shells occurs as signified by the arrow A in Figure 1.

The operation of the hinging arrangement of Figure 1 is well known in the art. The Figure 1 arrangement is mechanically reliable and quick to operate. However it suffers from the disadvantage that it is manufactured from a plurality of parts (ie. the half shells 11, 12 and the hinge pin 19).

The number of components needed therefore increases the cost associated with manufacture of the hinging arrangement. Moreover the need to assemble the parts together (by inserting the hinge pin 19 into the hinge eyes 18, following alignment of the eyes 18 in eg. a jig) increases the manufacturing cost.

Moreover when, as shown by the exemplary profile of the mutually engageable surfaces 13, 14 in Figure 1, it is desired to seal the cable closure the surfaces 13, 14 the profile of the side walls of the closure 10 in the vicinity of the surfaces 13, 14 cause spacing of the hinge pin 19 laterally from the mating line 16. In some designs the length of this spacing is 5-10mm, which (as a result of the secondary bending moment between the mating line 16 and the hinge pin 19) may result in undesirable, permanent deformation of the body of the cable closure 10.

Figures 2 A and 2B show respectively in their open and closed positions the half shells 11, 12 interconnected by an alternative, prior art interconnection arrangement in the form of a living hinge 21.

The living hinge is constituted by a thin web of eg. polymeric material that is moulded integrally with the half shells 11, 12 so as to interconnect them by way of a short, flexible strap.

The material of the living hinge 21 is chosen to permit its repeated bending (representing opening and closing of the half shells) without breaking.

The thinness of living hinge 21 contributes to this characteristic.

The living hinge is more cost-effective than the traditional, mechanical hinge of Figure 1. This is because it requires the manufacture of fewer components, which are in any event automatically created in a joined-together configuration by reason of an integral moulding process.

On the other hand, however, the living hinge 21 is, by reason of its dimensions, of limited strength, and hence limited creep resistance over time. Moreover only certain, highly flexible polymeric materials may be used to define the living hinge 21. This in turn limits the possible range of materials from which the half shells 11, 12 may be manufactured (since as noted in order to attain the advantages of the living hinge the latter must be moulded integrally with the half shells 11, 12).

Moreover, all the bending stresses that the living hinge 21 encounters act through the comparatively short length of the hinge strap. Thus a part of the hinge strap is stressed virtually regardless of the degree of opening of the half shells 11, 12. Another prior art solution is shown in Figures 3A and 3B, in which a connection strap 22 of considerably greater length than the living hinge 21 interconnects the half shells 11, 12 adjacent the mating line 16.

A strap such as strap 22 serves merely to prevent the half shells (or other mateable components) 11, 12 from becoming completely separated from one another e.g. during handling when the closure is open. A further closure arrangement (such as a nut and bolt assembly represented schematically by reference numeral 23) is needed to secure the joint between the half shells 11, 12. The strap does not contribute to the structural behaviour of the closure when it is closed. Thus the strap fails to assist in compressing the seals or keeping the closure shells in place when applying an external or internal load (e.g. internal pressure).

The use of additional fasteners such as the nut and bolt assembly 23 is associated with disadvantages in terms of the cost of inventory, the time needed to assemble the cable closure and the risk of loss of parts.

According to the invention there is provided an interconnection arrangement for two components having mutually engageable surfaces, the interconnection arrangement comprising a flexible strap that is secured at respective locations to the said components, the positions of the said locations and the length of the strap therebetween causing the strap to be:

(i) taut when the said surfaces of the said components are mutually engaged; and (ii) slack when the said surfaces are disengaged from one another.

Such an arrangement is advantageous since it provides the essential advantages of a living hinge (ie. modularity of construction and ease of use) without the constraints of such an arrangement in terms of the materials used and the localised application of bending stresses.

This is because the dimensions of the flexible strap in the arrangement of the invention permit firstly the use of a wide range of polymer types (including those of a greater hardness than traditionally provided in living hinges). Moreover the use of a comparatively elongate strap causes the bending stresses to be distributed over a comparatively greater length of the material of the strap than is the case for known living hinge designs. Such a strap can also be considerably thicker than the prior art arrangements (eg. 1 or 2 mm versus 0.3 to 0.4 mm for a living hinge). This implies much better structural strength, resulting in lower stress and strain in the material of the hinge for a given load.

Moreover, the feature of the strap becoming taut on mating of the mutually engageable surfaces means that the strap contributes effectively to the securing function of the interconnection arrangement, without a need for additional components such as the nut and bolt assembly of Figures 3 A and 3B.

Preferably one or more said location is spaced, in a direction perpendicular to a mating line corresponding to engagement of the said surfaces one with another, from the said mating line.

This feature assures that the flexible strap, when placed in tension by reason of mating of the mutually engageable surfaces promotes a seal between the aforesaid surfaces.

Conveniently the strap is manufactured from or includes a polymeric material, including but not limited to Polypropylene, Polyethylene, Polyamides (eg. "nylon"), or more elastomeric (rubber-like) materials or harder plastics such as ABS (Acrylonitrile Butadiene Styrene), PVC (polyvinyl chloride).

Preferably the thickness of the strap lies in the range 0.5mm to about 3mm. This is considerably thicker than has hitherto been possible in living hinges, the thickness of the strap part of which typically is in the range 0.2 - 0.5mm.

Thus the arrangement of the invention is considerably more robust than the known living hinge arrangements. Moreover the strap of the interconnection arrangement of the invention is noticeably less prone to creep and/or stress relaxation than the prior art living hinge designs. The length of the strap preferably exceeds 1mm, and may if desired exceed 50mm. The precise length of the strap is chosen according to the design of the components requiring securing.

The aforesaid strap lengths are several multiples greater than those typically used in living hinges, with the result as noted that bending stresses distributed over a greater length of strap material than is the case in the prior art; and less strain is induced in the material when hinging.

This in turn permits the use of a broader range of polymers than has hitherto been the case. Additionally it permits separation of the components requiring securing to a greater extent than is possible using eg. the mechanical hinge arrangement of Figure 1 or the living hinge arrangement of Figures 2 A and 2B.

The invention is also considered to reside in a cable closure or support apparatus including two components defining a pair of mutually engageable surfaces and including an interconnection arrangement as defined hereinabove.

Preferably the mutually engageable surfaces define a mating line corresponding to their mutual engagement; and the interconnection arrangement includes a single said strap that overlies a major part of the length of the mating line when the surfaces engage one another.

In an alternative arrangement, the interconnection arrangement includes a plurality of the said straps that are spaced from one another along the length of the mating line.

Thus the interconnection arrangement of the invention is particularly well suited for use in securing the two half shells of a cable closure. As described hereinbelow, however, the arrangement of the invention is additionally applicable in a wide range of other situations.

There now follows a description of preferred embodiments of the invention, by way of non- limiting example, with reference being made to the accompanying drawings in which:

Figure 1 is a partly sectioned view of approximately half of a cable closure including a mechanical hinge of a known type; Figures 2A and 2B are cross sectional views of approximately half of a prior art cable closure including a known living hinge arrangement;

Figures 3 A and 3B are cross sectional views of approximately half of a cable closure including a prior art flexible strap and securing bolt arrangement; Figure 4 is a cross sectional view of approximately half of a cable closure incorporating an interconnection arrangement, according to the invention, shown in its open position;

Figure 5 shows the components of Figure 4 when the parts of the cable closure occupy a closed (mutually engaged) position; Figure 6 shows in perspective, schematic view one way in which the interconnection arrangement of the invention may be applied to a cable closure;

Figure 7 is a perspective view showing an alternative to the Figure 6 arrangement; and

Figure 8 is a perspective view of a further component incorporating an interconnection arrangement according to the invention.

Referring to Figure 4, the half shells 11, 12 of a cable closure 10 of generally the same design as that shown in eg. Figures 2 and 3, and therefore having at least two mutually engageable surfaces 13, 14 that define a mating line 16 when the half shells 11, 12 are closed together, are interconnected by a flexible strap 23.

Strap 23 is secured at respective locations 24, 26 to the material of each half shell 11, 12 as shown.

The length of the flexible strap 23 is such that as shown in Figure 4 it is slack when the half shells 11, 12 are separated from one another such that the cable closure is open. However, when the half shells 11, 12 are pivoted as signified by arrow B in Figure 4 to a closed position, such that the surfaces 13, 14 engage one another to define the mating line 16, flexible strap 23 is in tension.

The locations 24, 26 of attachment of the flexible strap 23 to the respective half shells 11, 12 are spaced, in a direction perpendicular to the mating line 16, from the said mating line. Thus the tension in strap 23 that results on pivoting of the half shells 11, 12 to the configuration shown in Figure 5 serves to draw the two half shells towards one another such that the mating surfaces 13, 14 are firmly in engagement. This confers good sealing properties on the interconnection between the half shells 11, 12.

In the precise arrangement shown in Figures 4 and 5, the mutually engageable surfaces 13, 14 are part of a castellated profile to the mating edges of the half shells 11, 12. This arrangement has been found particularly suitable when it is desired to form a good seal between the half shells 11, 12; but in other arrangements the mutually engageable surfaces 13, 14 may take any of a range of other forms (including completely planar forms).

As noted, the thickness of the flexible strap 23 typically lies in the range 0.5mm to about 3mm. Its length exceeds lmm and in certain embodiments, in which the width of each half shell 11, 12 in the vicinity of the mutually engageable surfaces 13, 14 is significant, may be several millimetres, or even greater than 50mm.

As shown in Figure 6, the flexible strap 23 may if desired extend along the entire length of one side of a cable closure 10 so as to overlie the major part of the length along which the half shells 11, 12 are mutually engageable. In an alternative arrangement a series of flexible straps 23a, 23b, 23c spaced from one another at intervals, may provide for connection at several locations along the length of one side of a cable closure 10. .

Although not shown in the drawings, the cable closures of Figures 4 to 7 typically would include at the locations 27a, 27b mutually engageable detent formations for securing together the opposite sides of the half shells 11, 12 to those having the strap(s) 23 secured thereto.

Preferably but not necessarily the or each strap 23 is manufactured integrally with each half shell 11, 12. In alternative arrangements the strap(s) 23 may be manufactured separately from the half shells and then adhered (eg. using an adhesive compound or by welding) at either end to the half shells 11, 12. In the latter case the manufacturing would preferably involve the use of automated machinery in order to minimise the manufacturing cost. Preferably when the half shells 11, 12 and the flexible strap(s) 23 are moulded integrally one with another, they are made from Polypropylene, Polyethylene, Polyamides (eg. "nylon"), or more elastomeric (rubber-like) materials (which are also suitable for living hinge); or harder plastics such as ABS or PVC.

The engageable surfaces 13, 14 may if desired include interposed therebetween a gasket or a sealing compound such as a gel; or an air gap. Mutual engagement of the surfaces 13, 14 as specified herein embraces such arrangements even though the surfaces 13, 14 are not directly touching one another under such circumstances.

Figure 8 shows another arrangement, in which a support 28 for a pair of parallel cables (not visible in the drawings) is intended for insertion into a slot defined within a cable closure of the general kind shown in Figures 4 to 7.

The support 28 has formed therein a pair of through-going apertures 29 and is of the form of a generally rectangular plate.

Each apertures 29 extending inwardly from its periphery a plurality of deformable fingers 31 for supporting various diameters of cable.

Approximately a third of the circumference of each aperture 29 is defined by a pivotable part 32 which as shown is secured to the remainder of the cable support 28 by a flexible strap 23 of an interconnection arrangement according to the invention.

At its in-use upper end each pivotable part 32 includes a detent member 33 that is receivable in a slot 36 defined in a shoe 34 that also supports a further detent component.

Thus the arrangement of Figure 8 is moveable between the configuration shown in that figure to a further configuration in which each pivotable part 32 is retained by the detents in a location such that each aperture 29 is continuous and complete.

This arrangement facilitates the laying-in of cables into the apertures 29 when the pivotable parts 32 occupy the configuration shown in Figure 8. Thereafter the pivotable parts 32 may be pivoted to a closed position such that each cable is retained in its associated aperture 29. During this process the flexible straps 23 function in the manner described hereinabove, in conjunction with the detents. Thus the flexible straps contribute to the firm securing of the parts of the Figure 8 arrangement in their closed configuration.

As is apparent from eg. Figure 5, in use the flexible strap 23 of the invention is spaced from the mating line 16 of the components with which it is used, by only a comparatively short distance. Therefore the bending moment between a seal at the mating line 16 and the flexible strap that keeps it compressed is smaller than in the case of eg. the mechanical hinge of Figure 1. Consequently the effects of deformation or creep caused by secondary bending moments are less in the arrangement of the invention than in the prior art. In other words, a mechanical hinge as shown in Figure 1 will be loaded by bending rather than pure tensile loads as in the case of a strap. The invention therefore will always result in lower stresses and deformation in the material of the half-shells, resulting in structural advantage.

Although the invention has been described with reference certain embodiments, those of skill in the art will recognise that the principles of the invention are broadly applicable. It follows that a great number of variants on the precise arrangements shown are within the scope of the invention. Moreover the arrangement is useable in virtually any design of component having two sub-components requiring pivotable securing together. Its use is not limited to devices of the same size, mass, complexity or purpose as cable-closures or cable supports.

Claims

1. An interconnection arrangement for two components having mutually engageable surfaces, the interconnection arrangement comprising a flexible strap that is secured at respective locations to the said components, the positions of the said locations and the length of the strap therebetween causing the strap to be:

2. An interconnection arrangement according to Claim 1 wherein one or more said location is spaced, in a direction perpendicular to a mating line corresponding to engagement of the said surfaces one with another, from the said mating line.

3. An interconnection arrangement according to Claim 1 or Claim 2 wherein the strap is manufactured from or includes a polymeric material.

4. An interconnection arrangement according to any preceding claim wherein the thickness of the strap lies in the range 0.5mm to about 3mm.

5. An interconnection arrangement according to any preceding claim wherein the length of the strap exceeds lmm.

6. An interconnection arrangement according to Claim 5 wherein the length of the strap exceeds 50mm.

7. A cable closure or support apparatus including two components defining a pair of mutually engageable surfaces including an interconnection arrangement according to any preceding claim.

8. A cable closure or support apparatus according to Claim 7 wherein the mutually engageable surfaces define a mating line corresponding to their mutual engagement; and the interconnection arrangement includes a single said strap that overlies a major part of the length of the mating line when the surfaces engage one another.

9. A cable closure according to Claim 7 wherein the mutually engageable surfaces define a mating line corresponding to their mutual engagement; and wherein the interconnection arrangement includes a plurality of the said straps that are spaced from one another along the length of the mating line.

10. An interconnection arrangement generally as herein described, with reference to and/or as illustrated in Figures 4 to 8 of the accompanying drawings.

11. A cable closure generally as herein described, with reference to and/or as illustrated in Figures 4 to 8 of the accompanying drawings.