GB2340896A

GB2340896A - Edge seal assembly

Info

Publication number: GB2340896A
Application number: GB9818489A
Authority: GB
Inventors: Alan William Gimbert; Robert Paul Whitham
Original assignee: TARMAC UK Ltd; Tarmac Heavy Building Materials UK Ltd
Current assignee: TARMAC UK Ltd; Tarmac Heavy Building Materials UK Ltd
Priority date: 1998-08-26
Filing date: 1998-08-26
Publication date: 2000-03-01
Anticipated expiration: 2018-08-26
Also published as: GB9818489D0; GB2340896B

Abstract

An edge seal assembly comprises: first and second members, 11 and 18 respectively, having curved inner 12, 19 and outer 13, 20 surfaces; and a gasket 25 for use in a recess 24 between the two members 11 and 18. The thickness of the gasket 25 decreases from a thicker region, by the inner or outer curved wall, to a thinner region, by the outer or inner curved wall respectively. The thicker region of the gasket is preferably positioned closer to the curved wall experiencing greater fluid pressure. A second invention for use when both inner and outer curved walls experience high fluid pressure is also disclosed (see fig 4).

Description

2340896 PATENTS ACT 1977 DJL/A9262GB Title: Edge Seal Assembly

Description of Invention

This invention relates to an edae seal assembly and more particularly but c) not exclusively to such an assembly for a tunnel lining or pipeline which is made u of members alTanged edge to edge, which edge joint requires sealing p C C C against the ingress or egress of fluid, usually liquid.

0 0 0 It will be appreciated that in a typical tunnel lining application, an extrados side surface of the lining may be subjected to substantial fluid pressure and the joints between adjacent tunnel lining members must be able to prevent the ingress of such fluid.

It is com-mon practice to provide scaling material between the edges of adjacent members, sucli as a rubber or sirnilar gasket. As the members are urged togetlier the gasket is subjected to compression forces in the direction in 4) t> vhlch the members are brought together and thus an ed(,e seal is effected.

C> 0 t) However in use the gasket is subjected to fluid pressure in a transverse direction and sometimes fluid can leak past the gasket.

It is an object of the present invention to provide a new or improved jedge seal assembly whicli overcomes or reduces this problem.

According to one aspect of the itivention v,.e provide an edge seal assembly comprising a first incinber liaving Mt-rados and extrados side surfaces and a first ed-e bet,eeii the side surfaces, and a second member havinc, 0 In intrados and extrados side surfaces and a second edge between the side C surfaces. each of the first and second edoes in use facing one another and at 0 t> least one of the edges lia,iiig a recess. and there being a gasket receivable 1 C) 2 between the first and second edges and being receivable in part in the recess characterised in that the thickness of the gasket decreases from a thicker region which is positioned more closely adjacent the intrados or extrados side surfaces, to a thinner region which is positioned more closely adjacent the extrados or intrados side surfaces respectively.

Thus by providing the gasket in such configuration improved sealing > C against the ingress or egress of fluid can be achieved.

Where the intrados or extrados side surfaces of the assembly are adapted to be exposed in use to a greater fluid pressure than the extrados or intrados side surfaces respectively, the gasket may be arranged such that the thickness of the gasket decreases from a side more closely adjacent to the intrados or extrados side surfaces which are in use exposed to the greater fluid pressure.

Alternatively where each of the intrados and extrados side surfaces are adapted to be exposed in use to fluid pressure, the first and second members being operative to maintain the fluids separate, the gasket may thus comprise a first pail the thickness of which decreases fi-om a thicker region which is positioned more closely adjacent to the intrados side surfaces to the thinner region, and a second pail the thickness of which decreases from a thicker region which is positioned more closely the adjacent the extrados side surfaces C> such that the gasket has a minimum thickness in a region between the thicker regions and a maximum thickness or thicknesses towards the intrados and extrados side surfaces.

In each case the effect of the fluid pressure from the extrados or intrados surface is to urge the thicker reolon or i-e,,loiis of the--asket towards the thinner I-C,(-,1011 thereof Preferably the recess in the edge of the first or second member decreases in depth from a side more closely, adjacent to intrados and/or extrados side surface x,,liicli is in use exposed to fluid pressure. Thus the thicker region or 3 regions of the gasket is/are urged into a decreasing smaller r ecess, volume by the fluid, to aid sealing.

Generally, the recess in the edge of the first and/or second member may be configured generally to correspond to the cross-sectional profile of the gasket.

Preferably the gasket comprises in the main, a length of an elastic material such as rubber although if desired in addition to the elastic material of the gasket, hydrophillic sealing, material may be provided between the edges of the first and second members, arain to aid sealing.

In one example the hydrophillic material is separate from the gasket but preferably is attached to the gasket or integral with the gasket. For example where the gasket comprises an extrusion, the hydrophillic material may be coextruded with the gasket.

In each case if necessary, the recess in the edge of the first or second 0 member may be particularly configured so as to accommodate the hydrophillic material therein.

To aid deformation of the gasket particularly as compressive forces are applied as the first and second members are positioned adjacent one another, the gasket may have at least one internal chamber.

In one embodiment, in cross-section, the gasket may comprise a first m Jor surface which extends,,,,enerally parallel to the edges of the first and ai C> In second members, a second major surface which is inclined to the edges of the 0 first and second members, and side faces between the first and second major surfaces. To fuillier aid sealing the side face of the gasket towards the intrados or extrados side surfaces froin where the thickness of the gasket decreases, may comprise a pair of inclined face parts.vh1ch may meet on a line towards the adjacent side surfaces with at least one of the face parts inclined away from the line..

4 The line where the pair of face pails ineet may be located within the recess of the edge of the first or second member.

In each case, the gasket may comprise a symmetrical or non-symmetrical cross-sectional configuration.

According to a second aspect of the present invention we provide a tunnel lining or pipeline including an edge seAl assembly according to the first aspect of the invention.

According to a second aspect of the invention we provide a gasket for an edge seal assembly accordino to the first aspect of the invention.

0 The invention will now be described with reference to the accompanying drawings in which:- FIGURE 1 is a diagrammatic exploded perspective view of an edge seal assembly in accordance with the invention.

FIGURE 2 is a plan view of pail of the assembly of Figure 1 0 FIGURE 3) is an enlarged cross-sectional view through a gasket for use in the assembly of Figure 1 and FIGURE 4 is a view similar to Figure 2, but showing an alternative configuration.

Referrino to Figure 1, an edge seal assembly 10 comprises a first C C 0 member 11 which has intrados 12 and extrados 13) side surfaces, and a first edge 15 between the side surfaces, and a second member 18 having an intrados 19 and extrados 20 side surfaces and a second edge 21 between the side surfaces 19 and 20, the first and second edges 15 and 21 facing one another in use.

The first and second inembers 11 and 18 are in this example, tunnel lining inembers. In this example, the ttinnel extends generally in the direction - c of arrow A sucli that the members 11 and 18 each have a curvature extending c away from their respective edges 15 and 21, the edoes 15 and 21 being generally planar and linear.

The edge 15 of the first member 11 comprises a recess 24 which is adapted to receive a gasket 25 such that as the first 11 and second 18 members are brought together the gasket 25 which projects from the recess 24, forms a seal between the adjacent edges 15 and 21. It will be appreciated that a substantial compressive force may be applied to the gasket 25 so that it provides a seal.

In a typical tunnel lining application, where the inside of the tunnel is C> intended to be dry, the tunnel lining members 11 and 18 form a barrier to fluid from the extrados side surfaces 133 and 20 entering the tunnel, and the edge seal between the first and second members 11 and'18 thus needs to be substantially fluid tight. The fluid pressure to which the extrados side surfaces 13 and 20 exposed, may be can be substantial.

Referring now also to Figures 2 it can be seen that the recess 24 and the gasket 25 are each of a non-syrninetrical but generally corresponding configuration. The general thickness of the gasket 25 decreases from a thicker region 26 to a thinner re(fion 27, the thicker re-ion 26 being located more 0 C C closely to the extrados side surfaces 13 and 20 than the intrados side suifaces 12 and 19 of the first and second members 11 and 18.

The recess 24 in the edge 15 of the first inernber 11 is correspondingly configured, decreasing in deptli fi.om a deeper region 28 to a shallower region C. C> C:1 29. Thus as fluid exerts pressure on the exti-aoos side surfaces 13) and 20 of the members 11 and 12 and on the gasket 25, the thicker region 26 of the gasket 25.will be urged sideways in the recess 24 towards the lower volume shallower recess i.co i on 29. Thus increasing fluid pressure merely, improves the scaling C 0 effectiveness of the gasket 25.

Referrina now also to Figure -33, it can be seen that the gasket 25 C C> comprises a generally, elongate lengtli of preferably elastic material, havin...

C5 1,, i n this example three, internal chambers 30 which aid deformation of the gasket particularly as conipressive forces are exerted in the directions of the arrows 6 B and C in Figure 2, as the first and second members 11 and 12 are brought together, as well as in response to fluid pressure at the extrados side surfaces 13 and 20.

In this example, the gasket 25 comprises a first major surface 32 which extends generally parallel to the side edges 15 and 21 of the first and second members 11 and 18, and which may be received in a recess in the edge 21 of the second member 18 if desired. Further, the gasket 25 comprises a second major surface 33 which is inclined to the side edges 15 and 21 of the first and second members 11 and 18, and to ther first major surface -332, and the gasket comprises side faces 34 and -335 between the first and second major surfaces 3 52 and 33. Each of the side faces J4 and 35 comprises a pair of inclined face pails 36 and 37, and 38 and 39. The side faces 36 and 37 meet on a line 40 and the face pails 36 and 37 incline away fl-om th.e adjacent extrados side surfaces 13 and 20. It can be seen from Figure 2 that the line 40 is located within the C71 recess 24 of the edge 15 of the first member 11. It has been found that such an arrangement further enhances the sealing effect achieved by, the gasket 25 in C response to fluid pressure exerted on the extrados side surfaces 13) and 20 and on the gasket 25.

Further to aid sealing, as the first and second members 11 and 12 are brought togetlier, the second major surface 33) of the gasket 35 comprises a pair of recesses 43).

If desired, in addition to the rubber gasket 25, alternative sealing material may be provided bet\,.eeii the edges 15 and 21 of the members 11 and 12. In figure -33 it can be seen that the gasket 25 is co-extruded with such C additional material 45 and 46, the material 45, 46 beinghydrophillic material C which swells when subjected to liquid. Thus the hydrophillic material 45 mid 46 is integral with the reniainder of the generally elastic rubber gasket 25, C although hydrophillic material 45, 46 could be provided in addition to the 0 gasket 25 in an alteniative arrangement. Preferably the oasket 24 in the ed.e Z- 0 C 7 of the first member 11 is configured in any event, to accommodate such hydrophillic material 45 and 46 where provided, and where necessary.

As mentioned above, if desired the edge 21 of the second member 12 may have a recess to receive the first major surface 32 of the gasket 25, or the first major suiface -332 may simply engage the otherwise plain edge 21 of the 0 member 12.

Various other modifications may be made within departing from the scope of the invention.

The assemblies 10 so far described are particularly suitable to an application where there is fluid pressure on only the extrados 13, 20 side surfaces of the members 11 and 12, and the object is to prevent such fluid entering the inside of a tunnel. In another application, such as a pipeline, fluid pressure may be exerted on the intrados side surfaces 12 and 19 of the members 11 and 12, the object being to prevent such fluid escaping frorn the pipeline to C C1 the extrados side surfaces 1 3 3 and 20. In that event it would be appreciated that the recess 24 would need to be of an opposite configuration such that the C thicker region 26 of the gasket 25 would need to be accommodated closer to the intrados side surfaces 12 and 19 than the thinner region 27 which would be located closer to the extrados side surfaces 13 and 20.

If desired, the gasket 25, instead of having a major surface 352 which is t> generally parallel to the edges 15 and 21 of the menibers 11 and 12, may also 0 be inclined relative to the edges in which case, a recess of corresponding 1 C configuration would need to be provided in the edge 21 of the second member 1 - 0 12 in addition to the recess 24 in the edge 15 of the first nieniber 11, to receive C the---asket 25 0 In yet another application, the first and second nienibers 11 and 12 lilay. serve to separate fluids on the extrados 13) and 20 side surfaces and the intrados 12 and 19 side surfaces of the nienibers 11 and 12.

8 Thus fluid pressure may be exerted in both opposite directions on the gasket 25 generally normal to the directions of arrows B and C shown in Figure 2 and Figure 4.

Referring now to Figure 4, an alternative form of edge seal assembly for such application is illustrated. Again, the general thickness of the gasket decreases from a thicker region 26 closer adjacent to the extrados 13 and 20 side surfaces towards a thinner region 27 located closer adjacent to the intrados 12 and 19 side surfaces, but the thickness of the gasket 25 then again increases towards a further thicker region 26'which is closer adjacent to the intrados side surfaces 12 and 19 compared to the thinner region 27 which is now located closer to the extrados side surfaces 13) and 20. Thus the thinner region 27 comprises a waist in the gasket 25. Recesses 24 and 24' are provided in each of the edges 15 and 21 of the first and second members 11 and 12 to accommodate the gasket 24. Again it can be seen that side faces 34 and 34a of the gasket 25 between first 32 and second 333 major surfaces, each comprise a pair of inclined face pails which ineet at a line 40, 40' and the face pails are inclined away from the lines 40, 40'.

The gasket 25 shown in Figure 4, when exposed to fluid pressure on the 0 extrados surfaces 1-35 and 20, urges the thicker region 26 of the gasket 25 towards the lower volurne thinner region of the recess 24, and when subjected C? to fluid pressure on the intrados side surfaces 12 and 19, the thicker region 26, is urged towards the thinner lower volume re-lon 27 so that sealing is improved whether the fluid pressure is applied to the extrados 13), 20 and/or intrados 12 and 19 side surfaces.

Ag,ain the gasket 25 shown in Figure 4 could include or be attached to or be integn-al with eleinents of anothet. sealiii,,.,, material such as hydrophillic material located between the ed-es 15 and 21 of the first and second members 11 and 1 8 9 It will be appreciated that the actual configuration of the gasket 25and corresponding recesses 24 may be changed to suit different applications although in each case, there will be a thicker gasket region closer adjacent to one of the side surfaces which may be subjected to a fluid pressure greater than the pressure at an opposite side surface of the assembly.

The features disclosed in the foregoing description, or die following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing, the disclosed function, or a method or process for attaining the disclosed result. as appropriate, may, separately, or in any combination of such features, be udlised for i. ealisiii,,,, the Diventioii in diverse forms thereof

0

Claims

1. An edge seal assembly comprising a first member having intrados and extrados side surfaces and a first edge between the side surfaces, and a second member having intrados and extrados side surfaces and a second edge between the side surfaces, each of the first and second edges in use facing one another and at least one of the edges having a recess, and there being a gasket receivable between the first and second edges and being receivable in part in 0 the recess characterised in that the thickness of the gasket decreases from a thicker region which is positioned inore closely adjacent the intrados or extrados side surfaces, to a thinner region which is positioned more closely adjacent the extrados or intrados side surfaces respectively.

2. An assembly according to claim 1 wherein the intrados or C> extrados side surfaces of the assembly are adapted to be exposed in use to a greater fluid pressure than the extrados or intrados side surfaces respectively, the thickness of the gasket decreasing fl.om the thicker region which is 0 positioned more closely adjacent the intrados or extrados side surfaces which are in use exposed to the greater fluid pressure.

c n J. An assembly according to claim 1 wherein each of the intrados and extrados side suifaces are adapted to be exposed in use to fluid pressure, the First and second inembers bemo operative to maintam the fluids separate, the gasket comprising a fli-St part the thickness of which decreases fl-olil a thicker region which is positiotied more clearly adjacew the intrados side surfaces, to the thinner region, aiid a secorid part the thickness of which decreases from a C thicker region which is positioned more closely adjacent the extrados side W surfaces such that the gasket has a mininium thickness in a region between the thicker regions and a maximum thickness or thicknesses towards the intrados and extrados side surfaces.

4. An assembly according to claim 2 or claim 3 wherein the recess in the 0 edge of the first or second meinbei. decreases in depth from a side more closely adjacent to intrados and/or extrados side surface which is in use exposed to fluid pressure.

5. An assembly according to claim 4 wherein the recess in the edge of the first and/or second member is confioured generally to correspond to the crosssectional profile of the gasket.

6. An assembly according to any, one of the preceding claims wherein the :> C gasket comprises in the main, a Icii,(itli of an elastic material.

7. An assembly according to clairn 6 wherein the material fl-om which the 0 gasket is made comprises in the rnain, rLibber.

8. An assembly, according to claim 6 or claiin 7 wherein in addition to the 0 elastic material of the gasket, hydrophillic sealing material is provided between the edges of the first and second menibers.

c) 9. An assembly according to claini 8 wherein the hydrophillic material is attached to or inteoral with the -asket.

0 C" 10. An asseinbly accoi-(11'ii,, to claiiii 9 wherein the gasket comprises an extrusion and the hydrophillic niaterial is co-extruded with the gasket.

12 11. An assembly according to any one of claims 8 to 10 wherein the recess in the edge of the first or second member is configured so as to accommodate the hydrophillic material therein.

12. An assembly according to any one of the preceding claims wherein the gasket has at least one internal clianiber.

14. An assembly according to any one of the preceding claims wherein in 0 cross-section the gasket comprises a first major surface which extends generally parallel to the edges of the first and second members, a second major surface I which is inclined to the edges of the first and second members, and side faces between the first and second major surfaces.

15. An assembly according to claim 14 wherein the side face of the gasket towards the intrados or extrados side surfaces from where the thickness of the gasket decreases, comprises a pair of inclined face pails.

16, An assembly accoi-dim, to claim 15 wherein the pair of face parts meet 0 on a line towai-ds the adjacew side surfaces and at least one of the face parts is inclined away fi-om the line.

17. An assembly according to claim 16 wherein the line where the pair of face parts meet is located within the recess of the edge of the first or second CD member.

18. An assembly accot-dim-, to any oiie of the pi-eceding clanns wherein the ID 1 Z_ gasket comprises a symmetrical or non-symmetrical cross-sectional configuration.

13 19. An edge seal assembly substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

20. A tunnel lining or pipeline including an edge seal assembly according to any one of the preceding claims.

21. A tunnel lining or pipeline substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

C> 22. A gasket for an edge seal assembly accordinp to any one of claims 1 to c 0 20.

23. A gasket substantially as liereinbefore described with reference to and as shown in the accompanying drawings.

24. Any novel feature or novel combinatior) of features described herein and or shown in the accompanying drawings- C Z:>