GB2362514A - Metal cable enclosure having ports which can be cut open - Google Patents

Abstract

A method of providing a metal cable splice closure (1) having closed-off cable ports (3) which may be cut open upon installation includes the steps of providing a metal cable splice closure (1) having open cable ports (3) and pre-installing heat-recoverable caps (4) on the cable ports (3). The heat-recoverable caps (4) can easily be cut open in the field. By installing the caps in the factory instead of in the field, the installing can be carried out under controlled conditions, providing a better seal and simplifying the use of the closure in the field.

Description

2362514 METAL CABLE CLOSURES The present invention relates to metal

closures for cable splices. More in particular, the present invention relates to a metal cable splice closure having closed-off cable ports which may be cut open upon installation and to a method of providing a metal cable splice closure having closed-off cable ports which may be cut open upon installation.

Metal cable splice closures are used for enclosing and protecting cable splices in various locations, but especially in locations where the conditions require a closure meeting high specifications. In particular. in sewers and tunnels metal cable splice closures are usually preferred over the usual ones which are e.g. tape wrapped or have a hard plastic casing.

The ports where cables enter and leave the closure must of course be tightly sealed. Heat-recoverable ("heat-shrink") sleeves have proved to be particularly advantageous for this purpose. Often not all ports of a closure are used so the unused ports must be closed off. It is possible to provide the closure with ports which are initially not open. That is, the metal ports may be dead-ended when the closure is manufactured. Upon installation in the field, the ports may be opened as required by cutting open or sawing offthe closed end. However, this proves to be rather difficult and laborious. For this reason, it is preferred to manufacture a metal closure with open-ended ports. In practice, therefore, the unused open ports are closed off in the field by applying a cap, preferably a heat-recoverable cap. This, however, has several disadvantages.

In the first place, the metal closure acts as a heat sink for the heat applied during the heat-recovering process. This requires large amounts of heat to be applied in a very careful manner to achieve a proper shrinkage and sealing of the heat-re coverable cap. The large amounts of heat required and the excellent heat conducting properties of the metal closures may result in other parts of the closure being over- heated. In the second place, the process of heat-shrinking necessarily includes the use of a torch or other heat generating means, which is often considered a disadvantage when installing closures in tunnels, sewer pipes, etc..

1 It is therefore an object of the present invention to eliminate these and other disadvantages of the Prior Art.

It is a further object of the present invention to propose a method of providing a metal cable splice closure which reduces the amount of work in the field.

t is another object of the present invention to propose a method of providing a metal cable splice closure which provides a more reliable sealing.

It is a yet further object of the present invention to provide a metal cable splice closure requiring less work upon installation while having an improved sealing.

These and other objects are met by a method as defined in the preamble which according to the present invention is characterised by providing a metal cable splice closure 15 having open cable ports and pre-installing heat-recoverable caps on the cable ports.

By pre-installing heat-recoverable caps, that is, installing the caps in the factory, it is possible to carry out the heat-recovery process using optimised equipment under controlled conditions. Thus over-heating of the closure can easily be avoided and quality control of the 20 seal attained by the shrunk cap can easily be carried out.

In the field, the heat-shrunk cap can easily be cut if necessary, much easier than a metal port or cap.

The method of the present invention is therefore advantageous in that it ensures a better sealing of the heat-recoverable end caps, avoids over-heating of the metal closure, and greatly facilitates the installation in the field as there is no need to apply heat in the field or to saw off metal ports.

The present invention also provides a metal cable splice closure having closed-off cable ports which may be cut open upon installation, which closure is characterised in that the cable ports are closed ofFby pre-installed heat-recoverable caps.

1 The cable splice closure of the present invention is preferably made of stainless steel- However, other metals, such as aluminium, may also be employed.

The ports are preferably tubular and all ports may be located on one side of the body of the closure, said side of the body preferably being constituted by a separate end plate.

The invention additionally provides a kit-of-parts for forming a cable splice closure as defined above.

The present invention will further be explained below with reference to an exemplary embodiment illustrated in the accompanying drawings, in which:

Figure I schematically shows, in perspective, a metal cable closure according to the present invention.

Figure 2 schematically shows without the port caps.

in perspective, the end plate of the closure of Fig. 1 Figure 3 shows, in perspective, the end plate of Fig. 2 with the port caps applied.

The splice closure 1 shown only by way of nonlimiting example in Fig. 1 comprises a body 2 provided with cable ports 3. The cable ports 3 are shown to be substantially tubular and to project from an end plate 5 constituting a side wall of the closure. The ports 3 are closed off by end caps 4 to prevent the ingress of water into the closure.

In the embodiment shown there are eleven substantially tubular parts. Ten ports 3 have a circular cross-section, while one port 3' is an oval port. All ports are integral with an end plate 5 which constitutes one side of the closure 1. The body 2 of the closure 1, to which the end plate 5 is fitted, is closed off on all sides except the one where the end plate 5 is fitted. Screws 7 secure the end plate 5. The body 2 and the end plate 5 are preferably made of stainless steel, but other metals, such as aluminium, may also be employed.

The end plate 5 and the ports 3, 3's are shown in more detail in Fig. 2. The ports 3, 3' have openings or through-holes 6, 6' respectively which provide access to the interior of the closure when assembled. The ports may be welded onto the end plate 5 or may be integrally moulded. By providing a separate end plate the manufacture of the closure is 5 simplified.

In accordance with the present invention end caps 4, 4' are applied on the ports 3, 3' before the closure is used in the field. The resulting end plate is shown in Fig. 3. Of course the end plate 5 may first be mounted on the body 2 of the closure 1 before the caps are applied. However, it is preferred to apply the caps on a detached end plate as this reduces in the heat loss. If necessary the end plate may be taken from a pre-assembled closure to install the caps. After applying the caps, the end plate may be mounted on the body of the closure.

The caps 4, 4' preferably are heat-recoverable caps. Heat-recoverable materials are well known in the art and there are many Raychem patents describing these materials and their applications in great detail.

When installing the closure of the invention "in the field", that is, in a sewer, tunnel or other desired location, the ends of one or more caps 4, 4' are cut off to provide access to the interior of the closure. Cables may be passed through the opened ports and subsequently the ports are closed off again by applying an appropriate sealing member. Such a sealing member may advantageously be a heat-recoverable sleeve. The preinstalled caps 4, 4' provide a good base material on which to apply a heat-recoverable sleeve or other sealing sleeve or member. In addition, the cap acts as a heat barrier, thus facilitating any heat-recovery process in the field.

It will be understood by those skilled in the art that the present invention is not limited to the embodiments shown and that many additions and modifications are possible without departing from the scope of the present invention as defined in the appending claims.

Claims (10)

1. Claims

   Method of providing a metal cable splice closure (1) having closed-off cable ports (3) which may be cut open upon installation, characterised by the steps of..

   providing a metal cable splice closure (1) having open cable ports (3); and pre-installing heat-recoverable caps (4) on the cable ports (3).
2. 2. Method according to claim 1, wherein the metal closure (1) is made of stainless steel.
3. 3. Method according to claim 1 or 2, wherein at least some ports (3) are substantially 10 tubular.
4. 4. Method according to any of the preceding claims, wherein all ports (3) are located on one side of the body (2) of the closure (1).

   is
5. 5. Metal cable splice closure (1) having closed-off cable ports (3) which may be cut open upon installation, characterised in that the cable ports (3) are closed offby pre-installed heat-recoverable caps (4).
6. 6. Metal cable splice closure according to claim 5, wherein all ports (3) are located on an end plate (5) constituting a side of the closure (1),
7. 7. Metal cable splice closure according to claim 5 or 6, wherein at least some ports (3) are substantially tubular and have a substantially round cross-section.
8. 8. Metal cable splice closure according to claim 5, 6 or 7, wherein at least one port (3) has a substantially oval cross-section.
9. 9. Metal cable splice closure according to any of claims 5-8, made of stainless steel.
10. 10. Kit-of-parts for forming a metal cable splice closure according to any of claims 5-9.