WO2002037634A1

WO2002037634A1 - Cable sealing apparatus

Info

Publication number: WO2002037634A1
Application number: PCT/GB2001/004819
Authority: WO
Inventors: Alan Platt
Original assignee: Mct Brattberg Limited
Priority date: 2000-10-31
Filing date: 2001-10-31
Publication date: 2002-05-10

Abstract

Cable sealing apparatus comprises a frame (1), defining an aperture (12) in which a plurality of seal members (4, 6, 8) can be located. A removable frame part (2) has an arrangement part (18) with a rib (22) which acts to compress the seal members in the frame.

Description

CABLE SEALING APPARATUS

The present invention relates to cable sealing apparatus.

The invention is particularly although not exclusively, concerned with

a cable sealing apparatus, through which cables and/or pipes enter a cable

housing, providing an enclosure for electrical cables and junctions.

The cable sealing apparatus is located in a portion e.g. a wall of the

housing: Cables enter the housing via sealing sleeves or grommets

disposed in the cable sealing apparatus the grommets having apertures

through which respective cables pass.

Examples of typical cable housings are telecommunication cabinets,

and cable housing for trains, aircraft and control stations.

The term cable as used herein may be taken to refer to an insulated

electrical wire or cable or any pipe/conduit transmitting, e.g. for carrying

fluid e.g. water, gas, etc.

The seals must normally be compressed within the sealing apparatus

using packing pieces also located within the apparatus in order to provide

a sealing relationship between the frame and the seals and each cable so as

to prevent the ingress of liquids {primarily rain) and contaminants into the

housing. However, the problem arises in that the packing pieces occupy a

substantial amount of space with the sealing apparatus which thereby

reduces the space available for cables.

A further problem arises out of the common requirement for a sealing apparatus to cater for differently dimensioned cables or different numbers

of cables. This problem may be compounded in that the precise

type/arrangement of cables to be fitted (or re-fitted) varies substantially and

may often not be known until an engineer is on site (wherever the housing

is located). Thus the space occupied by cables in the cable sealing member

requirements and thus the packaging space also needs to be easily

adaptable to suit specific requirements.

An object of the present invention is to provide cable sealing

apparatus which is easily adaptable to suit a range of cables whilst being

operable to provide a sealing relationship with the cables.

Accordingly, according to one aspect of the invention therefore there

is provided cable access apparatus incorporating a frame for attachment to

a housing, said frame enclosing one or more resilient cable seals with

respective apertures through which respective cables can pass into the

housing and further incorporating compression means for compressing the

seals to provide a sealing relationship between the seals and the said

respective cables and characterised in that the compression means

comprises a portion of the frame.

With this arrangement, the seals may be compressed within the frame

to provide a sealing relationship therebetween (and between the seals and

the cables passing through the seals). However, because the compression

means is integral to the frame, space within the frame can be filled substantially entirely with seals.

The cable is preferably insulated electrical cable, however, the

invention is not intended to be restricted to this. Accordingly, the cable

may comprise any form of conduit, pipe, ducting, e.g. for carrying fluids

such as water, gas etc.

The frame may take any suitable shape and may, for example, have

a generally square or rectangular construction.

Preferably, the frame is a perimeter frame which surrounds/encloses

a region which, in use, is occupied by the seals.

The frame may be constructed from any suitable material which may

also be a fireproof material.

In one embodiment the frame is constructed from a thermoset plastic

e.g. GRP (glass reinforced plastic) or PVC (polyvinyl) chloride. Such

plastics are desirable as it is relatively inexpensive, robust, UV stable, and

will not rot/rust. Also the surface finish can be easily made flat for neat

interconnections.

The frame may have means for interlocking with the housing -or even

with another frame.

To this end, the frame may be constructed with its external sides

configured with either male and/or female interlocking portions (e.g. in a

tongue and groove arrangement).

In this way a housing may be fitted with a plurality of interlocking frames without the need for additional tools to enable said interlocking of

the frames.

Preferably, the compression means comprises all or part of a wall or

side or perimeter portion of the frame.

The compression means may comprise a first portion of the frame

which is movable relative to a second (or other) portion (s) of the frame so

as to compress the seals therein.

Preferably the compression means is movable in a direction towards

the second portion so as to compress the seals.

The first portion is preferably movable in a direction away from the

second portion so as to de-compress the seals.

The first portion may be movable and/or removable relative to the

second portion(s) of the frame so as to enable location of the seals within

the frame.

The first portion may be securable in position relative to the other

portions of the frame so as to compress the seals therewithin.

Thus, in one embodiment the compression means can be removed

from the frame to allow the seals to be fitted and is then replaced and

secured in a position in which it compresses the seals within the frame.

The first frame portion may incorporate a seal engagement means for

engaging the or each seal enclosed within the frame and located adjacent

the first frame portion to contact and so exert a compression force on said seal.

The seal engagement means may include a portion which protrudes

into the region enclosed by the frame.

The seal engagement means may be configured to engage with a

corresponding portion of the or each said adjacent seals. For example, the

seal engagement means may be/have a protruding portion e.g. edge/lip/rib

etc., which corresponds with a channel/slot/aperture etc. on each of the

adjacent seals.

The corresponding portions of the seal and seal engagement means

may extend along a whole or part of the seal/seal engagement means.

With this arrangement, the engagement means can contact the seal(s)

so as to exert a compression force thereon, but without reducing the space

within the frame for storage of seals.

Advantageously, the seals are arranged in mutually transverse rows

and columns within the frame.

Where there are insufficient seals to fill the space within the frame,

'blank' or 'blind' seals (i.e. without apertures) may be used.

The cable sealing apparatus may include one or more seal location

members which locate the seals in position within the frame.

The or each seal location member may take any suitable form for

example it may comprise an elongate bar or rod.

With this. arrangement very little space is taken up by the location member.

The location member may be used to transmit the compression force

to successive rows of seals.

The frame may include a portion which inter-engages with the or

each seal location member.

The frame may incorporate portions, for example, a groove or

grooves for inter-engagement with the seal location member. Thus, in one

embodiment opposing internal frame walls incorporate respective

longitudinal grooves with which respective end portions of the seal location

member slidably engage.

The frame may include a flange portion around at least a part of the

outer portion of the frame. Preferably, the flange portion extends generally

parallel to the direction in which cables lie when disposed in the frame.

The frame portion may incorporate apertures to allow fasteners to be

inserted therethrough for fixing purposes.

The cable seals may incorporate one or more portions e.g. one or

more grooves or channels or the like for inter-engagement with the or each

seal location member.

Advantageously the or each seal has inter-engaging portions on a

plurality of faces/sides of the seal so that the seal may be orientated in

more than one position and still be able to engage the location member.

The seals may take any suitable form, however, they are preferably resilient.

The seals may be of any suitable shape, but are preferably generally

square or rectangular to facilitate close packing within a generally square or

rectangular frame.

The seals preferably incorporate an aperture for receiving a cable.

The aperture may be any suitable shape to suite the cable. Preferably, the

aperture is generally circular (in cross section)

The or each seal may comprise two portions which inter-engage to

provide the seal.

The or each seal may include removable portions (e.g. tear-off

portions) which are configured to lie within and thereby affect the shape

and/or size of the seal aperture.

With this arrangement, different sized cables can be accommodated

by adapting the seal without the requirement of differently sized seals, or

in so far as the removable portions can be removed by hand, without tools.

Accordingly, in a second aspect the invention provides a seal for use

with a cable sealing apparatus such as the above described apparatus, the

seal includes an aperture for receipt of a cable therethrough, and further

includes one or more removable portions which are configured for location

adjacent or within the aperture and thereby modify the shape and/or size of

the aperture.

The removable portions may take any suitable form and may be circumferential strips, configured for location within a circular aperture in

the seal.

The seal may incorporate a locking groove to prevent lateral

movement of the or each removable portion relative to the seal, once in

place.

The or each seal may take any suitable form and may comprise a

sleeve. The seal(s) may be an 'open' grommet in which the aperture is

preformed or a 'blind' grommet in which the cable is pushed through a

membrane in the grommet to form the aperture.

The or each seal is preferably flexible and may comprise any suitable

resilient material e.g natural or synthetic rubber, or synthetic material e.g.

EPDM (i.e. ethylene propene).

Other preferred features of the seal are as described in relation to the

seals described in the first aspect of the invention.

Preferably, the compression means is secured in position by fasteners

accessible externally of the frame (thereby allowing ease of access thereto).

The fastener may be configured so that when located to secure the

compression means in position, the fastener does not protrude into the

space enclosed by the perimeter.

In this way, the fastener does not occupy space which could

otherwise be occupied by seals (and cables).

The fastener may engage the compression means (i.e. the first portion of the frame) and the second of the frame perimeter in any way so

as to secure these components together or in any way. For example, the

fastener may engage the frame portions by means of corresponding

threaded portions.

The fastener may pass through an aperture in the first portion and

then into engagement with e.g. aperture, through-hole, slot or the like of

the second portion of the frame.

The invention will now be described in detail, by way of example only

and with reference to the accompanying drawings in which:-

Fig. 1 is a perspective view of a frame of a cable sealing apparatus

according to one form of the invention.

Fig. 2 is a part sectional view of part of the frame of fig. 1 , showing

a fastening arrangement.

Fig. 3a and 3b are sectional views of a wall of the frame of Fig. 1.

Fig. 4 is a location member to be used with the frame of Fig. 1.

Figs. 5a and 5b are side views of seals for use in the apparatus of

Fig. 1.

Fig. 6 is a 'blank' or 'blind' seal for use in the apparatus of Fig. 1.

Fig. 7 is a plan view of a seal with removable portions according to

the invention.

Fig. 8 is a perspective view of the seal of Fig. 7;

Fig. 9 is a perspective view of an alternative frame according to the invention.

Referring to the drawings, a cable sealing apparatus is illustrated, the

apparatus located in a wall of a cable housing such as a telecommunications

cabinet (not shown). Electrically insulated cables (not shown) enter the

housing via the sealing apparatus as described below.

The cable apparatus comprises a frame 1 , shown in fig. 1 , with

compression means 2, comprising a removable portion of the frame 1 which

is secured in place using the fastening arrangement of Fig. 2.

Cable seals 4, 6, 8 (shown in Figs. 5 - 8) enclosed in the frame 1 and

located with stay bars 10 (one shown in Fig. 4).

The frame perimeter 1 is a one-piece moulding of glass reinforced

plastics (GRP) having a square shape, and defines a region 12 within the

frame, in which the seals 4, 6, 8 are arranged depending on the cabling

requirements. The removable portion 2 is also constructed from glass

reinforced plastic.

The frame 1 has three internal walls, each providing a longitudinal

channel 16 extending along the length of each wall and including an

elongate groove 14, in the centre of the channel 16.

The removable frame portion 2 providing the further wall 20 and this

incorporates seal engagement portion 18 having a longitudinal bar 22 (made

^"rom metal).

The outer portions of the frame incorporate channels 24 or there may be protrusions 26 shown in Fig. 3.

The side wall 28, 30 of the frame include respective threaded

apertures 32 for receipt of threaded bolts which secure the portion 2 in

place in the frame 1 (see Fig. 2).

Referring now to Figs. 5 - 8, the seals comprises two halves, each

having a central body portions 34 (one shown at Fig. 8) which is generally

box shaped and including a channel 36, generally semi-circular in cross

section.

Extending laterally from each side of the box portion are semi-circular

tear-off strips 38 of progressively decreasing thickness, as more clearly

shown in Fig. 7.

Within the channel 36 there is a central circumferential slot 40.

At opposing ends of this slot 40, there are radially directed locking

portions 42, more clearly seen in Fig. 5.

When two corresponding seal halves 4 are placed together to define

a single seal or sealing sleeve (not shown) the corresponding channels 36

define an aperture through which a cable may pass.

Fig. 6 shows a 'blank' portion 6 which may be used to seal off the

aperture of a seal to provide a 'blind' seal;

On each of the external faces of the seal's main body 36 are grooves

44.

Fig. 4 shows a stay bar comprising a thin elongate metal bar which is the same length as the distance between two opposing grooves 1 on

the internal walls 28, 30 of the frame 1.

. In use, seals are placed within the frame's central region 12, in rows.

Between each row, a stay bar 10 is inserted and slides into position by

means of the grooves 14 on the frame 1. The stay bar 10 is configured to

engage the grooves 44 on the seals 4.

The frame's middle region may ^' be filled entirely with seals.

Alternatively if, for example, only a few cables are to enter the housing via

the apparatus, blind seals can be used in place of open seals (i.e. seals with

apertures for cable receipt). A mixture of blind and open seals can be

placed together in the frame, in any configuration, allowing far more control

over the position of cables relative to the frame.

The removable portion 2 is then located into the frame top and

secured into position using the fastening arrangement as described above.

As the bolts 30 are turned the portion 2 moves down in a direction

toward the seals as does the seal engagement portion 18. The longitudinal

bar 22 of this portion engages with the external grooves 44 the seals in the

uppermost row.

As the seal engagement portion is moved downwards on the seals

these are compressed. Compression of the seals provides a sealing

relationship between the frame seals and cables so as to prevent the ingress

of liquids (e.g. rain) and contaminants within the housing. The seals may be modified in shape/size (before or after fitting in the

frame) by tearing off an appropriate strip 38 from the seal body and

inserting this in the slot 40. The radial locking portion 42 prevents lateral

slipping of the inserted piece when the cable is passed through the seal.

A plurality of frames may be used and the configurations of the

frames' external walls facilitates this. Frames may have interlocking male

and female sections 24 and 26 in a dovetail configuration.

Alternatively, the frames may all have 'female' channels and a

separate interlocking member 50 used to lock the frames together (see Fig.

3). With this arrangement, no additional tools are required to interlock

adjacent frames together.

Fig. 9 shows an alternative arrangement in which the frame includes

an outer flange portion 60. The flange has apertures 62 to allow fasteners

to be inserted therethrough, to enable fixing of the frame relative to e.g. a

cable housing, or advantageously in an aggregate block wall.

It is of course to be understood that the invention is not intended to

be restricted to the details of the above embodiment which are described

by way of example only.

Claims

1. Cable sealing apparatus comprising a frame (1 ) for attachment to a

housing and enclosing one or more resilient cable seals (4, 6, 8) with

respective (36) through which respective cables can pass into the housing, and compression means (2) for compressing the seals (4, 6,

8) to provide a sealing relationship between the seals (4, 6, 8) and

the respective cables, characterised in that the compression means

(2) comprises a portion (2) of the frame.

2. Cable sealing apparatus according to claim 1 , characterised in that said portion (2) of the frame comprises all or part of a wall or side or

perimeter portion of the frame (1).

3. Cable sealing apparatus according to claim 2, characterised in that

said portion (2) of the frame is moveable relative to other portions of

the frame (1 ) so as to compress the seals (4, 6, 8) therein.

4. Cable sealing apparatus according to claim 3, characterised in that

said portion (2) is moveable towards the other portions of the frame so as to compress the seals (4, 6, 8) and away from the other

portions of the frame so as to de-compress the seals (4, 6, 8).

5. Cable sealing apparatus according to claim 4, characterised in that

the position (2) can be removed from the frame (1 ) to allow the seals

(4, 6, 8) to be fitted and then replaced and secured in a position

wherein it compresses the seals (4, 6, 8) within the frame (1 ).

6. Cable sealing apparatus according to any proceeding claim,

characterised in that said portion (2) of the frame incorporates a seal

engagement portion (18) for engaging the or each seal (4, 6, 8)

enclosed within the frame (1 ) to contact and so exert a compression

force on said seal (4, 6, 8).

7. Cable sealing apparatus according to claim 6, characterised in that

said engagement portion (18) has a protruding portion (22) which

corresponds with a recess (44) in each of the adjacent seals.

8. Cable sealing apparatus according to claim 7, characterised in that

the frame (1) is capable of holding the seals (4, 6, 8) in mutually

transverse rows and columns within the frame, and that where there

are insufficient seals to fill the space (12) within the frame, blank or

blind seals (6) without apertures are used.

9. Cable sealing apparatus according to claim 8 characterised in that

one or more seal location menu (10) are provided to locate the seals

(4, 6, 8) in position within the frame (1).

10. Cable sealing apparatus according to claim 9 characterised in that the

frame (1) has one or more portions which interengage with the or

each seal location member (10).

1 1. Cable sealing apparatus according to any preceeding claim,

characterised in that the frame (1) comprises a flange portion (60)

around at least the outer portion of the frame, and extending generally parallel to the directions in which cables lie when disposed

within the frame.

12. Cable sealing apparatus according to any preceding claim,

characterised in that the seals (4, 6, 8) are generally square or

rectangular in cross-section and incorporate an aperture to receive a

cable.

13. Cable sealing apparatus according to claim 12 wherein the seals

comprise two portions which interengage to provide the seal and

have removable portions which lie within and effect the shape and/or

size of the seal aperture.

14. Cable sealing apparatus according to claim 1 , characterised in that it

comprises one or more seals (4, 6, 8) which each comprise an aperture for receiving a cable therethrough, and one or more

removable portions configured for location adjacent to or within the

aperture to thereby modify the shape and/or size of the aperture.

15. Apparatus according to claim 14 characterised in that the removable

portions are circumferential strips, configured for location in a circular aperture in the seal.

16. Apparatus according to claim 15, characterised in that the seal

incorporates a locking groove to prevent movement of the or each

removable portion relative to the seal, once in place.

17. Apparatus according to claim 16, characterised in that each seal is in the form of a sleeve either with a preformed aperture, or a closed

aperture closed by a membrane through which the cable is pushed to

form the aperture.