GB2192760A

GB2192760A - Pressure bulkhead cable lead through

Info

Publication number: GB2192760A
Application number: GB08708588A
Authority: GB
Inventors: Cecil Derek Thompson
Original assignee: British Aerospace PLC
Current assignee: BAE Systems PLC
Priority date: 1986-04-29
Filing date: 1987-04-10
Publication date: 1988-01-20
Anticipated expiration: 2007-04-10
Also published as: GB8610482D0; GB2192760B; GB8708588D0

Abstract

A pressure seal device for carrying electrical conductors through pressure retaining structures, eg, pressure bulkheads comprises a cable or cables 10 and conduit 11 sealingly located within a housing. The conduit is itself pressure sealed eg at 13. To introduce an additional cable 15 or cables the sealed portion of conduit is cut away, the cable 15 drawn through by means of a ready installed draw wire and subsequently encapsulated in a suitable sealing compound. <IMAGE>

Description

SPECIFICATION Pressure seal devices for electrical conductor installations This invention relates to pressure seal devices for carrying services such as electrical conductors through pressure retaining walls, e.g.

pressure bulkheads.

It is well known to provide devices, commonly referred to as pressure bungs, for enabling electrical cables to pass through a pressure retaining wall without loss of pressure.

For example, transport aircraft, being pressurised at altitude, include pressure bulkheads and pressure floors through which services frequently pass. In the case of electrical systems, the device may comprise a hollow generally cylindrical housing arrangement located to the-pressure retaining structure and which will accomodate a number of cable runs. When the full compliment of cables is installed an appropriate filling compound is introduced into the device, encapsulating the cables and sealing the interspace thus preventing pressure loss. The shortcoming of this arrangement is that it precludes the ready introduction of additional cables should this need arise because of the difficulty or impossibility of removing the compound and resealing. It is the object of the present invention to provide a solution to this shortcoming.

According to the present invention, an arrangement for carrying electrical conductor means through pressure retaining structures including an opening in said structure, a pressure seal device located to said structure substantially concentric with said opening, said pressure seal device including primary electrical conductor passageway means and at least one sealed supplementary electrical conductor carrying conduit located in said passageway means, characterised in that a pressure reactive sealing compound is introduced into said passageway to sealingly encapsulate primary electrical conductors passing therethrough and said conduit; the arrangement being such that when supplementary electrical conductors are required, the sealed portion of at least one of said conduits is removed to allow the installation of at least one supplementary conductor and thereafter a pressure reactive sealing compound is introduced into said conduit to sealingly encapsulate said supplementary conductor.

Preferably the conduit is of flexible convo luted form and the pressure sealing means is on the pressure side of the pressure retaining structure.

Preferably also a draw wire is inserted through the conduit for secondary conductor installation means and retained therein by conduit sealing means.

One embodiment of the arrangement will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is an elevation on a pressure seal installation arrangement according to the invention.

Figure 2 is a longitudinal cross-section through the arrangement of Fig. 1.

Referring to the drawings, these illustrate the installation in a pressure retaining wall 1 of a pressure seal arrangement according to the invention in which the pressure seal device 2 comprises a hollow cylindrical body portion 3 passing through the pressure wall 1 and to which it is located by means of a concentrically, disposed attachment flange 4 forming an integral part of the body portion 3, the wall including a reinforcement ring 5 of diameter substantially corresponding to the said attachment flange. The device further includes a right-angled body portion 6 rigidly attached to one end of the body portion 3 and includes a fairlead portion 7.The remote end of the body portion 3 includes screw threaded portion 3a for engaging a hollow body portion 8 comprising an internally threaded parallel body portion 8a and a conical intermediate body portion 8b terminating in a parallel portion 8c.

In the arrangement as illustrated, although the filler compound 9 is shown in situ it will be appreciated that this is only introduced after installation of the cables 10. In this embodiment the cables pass through the pressure seal device as illustrated, turned at rightangles at an acceptable radius of curvature and retained in the fairlead portion 7. A predetermined length of convoluted flexible conduit 11 also passes through the pressure seal device and is similarly turned at right angles at an acceptable radius of curvature and retained in the fairlead portion 7. The convolute conduit extends beyond the fairlead portion which is on the pressure side of the pressure retaining wall 1 and to a similar extent beyond the parallel body portion 8c.

With the full compliment of cables installed and the numbers may be greater than that illustrated, a proprietary filling compound 9 is introduced into the pressure seal device encapsulating the cable and the convoluted conduit and sealing the interspace. Similarly, the convoluted conduit is sealed at its extremity 13 on the pressure side of the pressure retaining wall 1 by means of a similar proprietary compound which is restricted in its depth by means 14 which may comprise a tape insert. Prior to this sealing process within the conduit a draw wire 15 is inserted as shown and which is similarly retained by the compound.

By this arrangement the insertion of additional cable runs can be speedily and readily achieved without disturbing the compound within the pressure device. That portion 13 of the conduit containing the compound can be cut away and additional cable runs inserted by means of the draw wire 15. On completion of this operation fresh compound is inserted into the conduit on the pressure side encapsulating the contained cables thus ensuring no pressure loss.

Although in this embodiment a single conduit is depicted, this may be varied by requirement and design. Similarly the arrangement may be equally applicable to installations where the cables and/or the conduit have no angular deviation.

Claims

1. An arrangement for carrying electrical conductor means through pressure retaining structures including an opening in said structure, a pressure seal device located to said structure substantially concentric with said opening, said pressure seal device including primary electrical conductor passagway means and at least one sealed supplementary electrical conductor carrying conduit located in said passageway means characterised in that a pressure reactive sealing compound is introduced into said passageway to sealingly encapsulate primary electrical conductors passing therethrough and said conduit, the arrangement being such that when supplementary electrical conductors are required, the sealed portion of at least one of said conduits is removed to allow the installation of at least one supplementary conductor and thereafter a pressure reactive sealing compound is introduced into said conduit to sealing encapsulate said supplementary conductor.

2. An arrangement according to Claim 1 in which said conduit is of flexible convoluted form.

3. An arrangement according to Claim 1 in which a draw wire extends through and beyond each end of each said conduit and retained therein by conduit sealing means.

4. An arrangement according to Claim 1 in which said sealing means is installed on the pressure side of the pressure retaining structure.

5. An arrangement according to any preceding claim substantially as described with reference to the accompanying drawings.