WO1992008021A2

WO1992008021A2 - Drainage system

Info

Publication number: WO1992008021A2
Application number: PCT/GB1991/001866
Authority: WO
Inventors: Graeme Staniforth
Original assignee: Hepworth Building Products Limited
Priority date: 1990-10-26
Filing date: 1991-10-25
Publication date: 1992-05-14
Also published as: WO1992008021A3; AU8763791A

Abstract

An adjustable rainwater gutter bracket consists of a bracket arm (1) with horizontal teeth (17) at its rear, a mounting block (3) with horizontal teeth (37) at its front, and a locking slide (5) housed in the mounting block. Lugs (21) on the bracket arm can enter a channel in the mounting block to retain the bracket arm loosely while allowing the teeth to be inter-engaged at different relative heights. The locking slide can lock a hook (57) provided on the bracket arm, to hold the bracket arm against the mounting block with the teeth firmly inter-engaged. This enables the height of the gutter to be easily adjusted. The mounting block is installed first, the bracket arm is fitted to it subsequently. A gutter seal strip (69) may have an integral resilient pad (91) at its end, to be trapped between the gutter edge and a rigid retaining clip (77) of a gutter fitting, to retain the gutter reliably without requiring accurate moulding of the gutter fitting. The seal strip may have a non-uniform external cross-section with a rib (75) engageable in a recess provided in the fitting, to retain the seal strip without requiring an end lip on the fitting. The seal strip may incorporate stiffer edge regions (83, 85).

Description

DRAINAGE SYSTEM

This specification relates to rainwater drainage systems.

Rainwater drainage equipment is now universally made of plastics material, in general PVC, and comprises extruded gutter sections, and injection-moulded fittings. The fittings comprise, among others, support brackets, unions, corner pieces, downpipe connectors and so on.

Conventional guttering systems have a number of deficiencies and in particular are not easy to install, because of the need for accurate placing and levelling of the one-piece support brackets by which the gutters are attached to a building or other structure.

The provision of an improved rainwater drainage system is therefore very desirable.

A first aspect of the present invention resides in an improved manner of supporting the gutter and fittings and attaching them to a building. More specifically, there is provided a guttering system for rainwater comprising at least one support adapted to be secured to or incorporated in a structure, at least one length of gutter, and at least one gutter fitting adapted to engage with and to support the gutter, the said fitting(s) and support(s) having mutually inter-engageable configurations whereby the fitting(s) can be mounted on and supported by the support(s).

For the avoidance of doubt it is here stated that the term " fitting" herein includes gutter support brackets as well as fittings which actually form part of the gutter channel, unless the context requires otherwise.

Such a system has practical advantages, because it will usually be easier to install and level the support or supports, than is currently the case with conventional gutter systems. Furthermore, a common design of support can be used in conjunction with fittings and guttering of a range of different profiles.

A separate support, individually attached or attachable to a structure, may be provided for each gutter fitting. Such support may be designed to restrain the associated fitting from moving horizontally in a direction generally parallel to the line of the gutter, or it may be such as to permit limited sliding movement of the fitting parallel to the line of the gutter, to facilitate placing of the fitting correctly relative to the gutter. Short lengths of a support rail or bar each provided with a suitable inter-engagement configuration may be interconnected by integral or separate flexible lines in an arrangement resembling a "washing line", to be attached to a fascia board or other element of a structure. This can provide a multiplicity of fitting mounting points in a compact form.

Our British patent application 9023316.4 sets forth rainwater systems as outlined above.

The present specification concerns, inter alia, improvements in such rainwater systems.

According to one aspect of the present invention there is provided a gutter support bracket or gutter fitting comprising a first element engageable with a gutter, a second element adapted to be mounted on a building or other structure, these elements having complementary readily inter-engageable and disengageable locating formations adapted to define, when inter-engaged, the vertical relative positions of the elements, and releasable fastening means, having a first position in which the said formations are held inter-engaged, and a second position in which the said formations can be disengaged.

In use, the second element is fixed to a structure, with the two elements separated. Subsequently the first element is engaged with the fixed element, and the fastening means are operated to prevent the elements from becoming disengaged.

Preferably, the inter-engageable formations are so designed that the elements can be inter-engaged selectively at different relative vertical positions. As a result of this feature, errors in the initial vertical positioning of the element fixed to the structure are of little or no importance, because the requisite vertical level of the gutter can be adjusted by selectively engaging the elements together at the appropriate relative heights.

The inter-engageable formations are preferably horizontal teeth, which may for example be of saw-tooth profile. Alternatively, there may be only a single such formation on each element. In this case, vertical adjustment of the elements is not possible, nevertheless installation is easier than with a conventional gutter fitting or bracket, because a relatively simple element is first fixed to the structure, and the other element, which is the gutter fitting proper or a gutter-supporting bracket element, can be fitted subsequently to the fixed element.

In a preferred embodiment, the first and second elements are shaped so that they can be relatively loosely connected to one another while remaining capable of movement such as to engage and disengage the said formations.

A second aspect of the present invention concerns the provision of a seal between a gutter and a gutter fitting.

Conventionally, a seal strip is trapped between the gutter and gutter fitting, under pressure exerted by a clip integral with the fitting, or a separate clip. These clips comprise rigid integral lips under which the gutter edges are pushed. This is inconvenient, difficult to manufacture accurately, and liable to cause damage to the lips or the gutter. The lips must be capable of yielding sufficiently to allow the gutter to be inserted under them, yet at the same time the lips must exert enough pressure to ensure sealing between the gutter, seal strip and gutter fitting. Combining these requirements is difficult in practice.

According to the second aspect of the present invention, sealing is effected by a seal strip and rigid or semi-rigid lips under which the gutter is clipped, but a resilient member, e. g. a resilient pad, buffer, or spring, is additionally provided between at least one edge of the gutter and the corresponding lip.

This resilient member provides most or all of the relative yielding movement necessary to allow the gutter to be engaged under the lip, and provides all or part of the resilience necessary to cause the gutter to exert pressure on the seal strip.

The resilient member can be a pad made of a relatively soft material; it can be relatively thick, compared with the retaining lips, and consequently can accept a substantially greater degree of relative movement of the gutter and lip, while exerting adequate sealing pressure; the result is a dramatic reduction in the accuracy with which the gutter and lips have to be made in order to achieve satisfactory sealing. Manufacturing tolerances can therefore be relaxed.

The resilient member can be a separate element, or it can be attached to the clip for example by an adhesive or co-moulding, but preferably, it is a pad formed integrally or otherwise provided on one end of a seal strip, as a local increase in the seal strip thickness projecting towards the interior of the gutter.

According to another aspect of the present invention, a gutter seal strip may have, in cross-section, a profile with regions of different depth, and gutter fittings have transverse seal-receiving recesses of matching profile, such that the gutter fitting and seal strip inter-engage in a manner resisting movement of the seal strip in the longitudinal direction of the gutter.

In particular, the seal strip may have, at one edge, an outwardly (downwardly) projecting bead or lip, engageable with a corresponding internal groove provided in a gutter union or other fitting. Preferably this groove and lip are placed to be at that side of the seal strip which is further from the end of the union or fitting. According to yet another aspect of the present invention, a seal strip may comprise, in cross-section, at least two regions of different stiffness or mechanical strength namely at least one edge region of greater stiffness or strength, and at least one further region of lower stiffness, and greater flexibility and compressibility.

Preferably there are two stiffer edge regions, and an intervening softer and more flexible and resilient region. The edge region or regions provide mechanical strength while the further region provides the resilience and flexibility required for sealing.

The said regions can be united with one another in any convenient way for example by an adhesive or by co-extrusion, but preferably they are made by co-moulding, in particular injection moulding.

Conventionally, gutter seal strips are made by extrusion, being of uniform cross-section throughout the length of the strip.

We have found that the production of seal strips by injection moulding instead of extrusion has a number of practical advantages. It makes it relatively easy to combine different materials or different properties in a single seal strip. It makes it possible to provide a cross-section which is not constant throughout the length of the strip: thus, a seal strip with an integral resilient pad or buffer at one end, as described above, can be produced by injection moulding but not by extrusion; an injection moulded strip can have a cross-section which varies along its length, which in turn can provide enhanced sealing at different positions along the length of the strip, for example to cope with variations in sealing pressure and/or variations in gutter profile, as described for example in our British patent application 9025328.7.

Rainwater guttering components embodying the features of the present invention will now be described with reference to the accompanying drawings in which: -

Figure 1 is an exploded perspective view of a gutter bracket embodying the invention.

Figure 2 is an exploded view of a fixing element shown in Figure 1. Figures 3 and 4 are views on a vertical section line, showing how the components illustrated in Figures 1 and 2 interact.

Figure 5 is an exploded perspective view of a gutter union and seal strips, and

Figure /is a detail, in longitudinal cross-section of the seal strip assembled into the gutter union.

Figures 1 to 4 shown an adjustable gutter bracket. This comprises three elements, conveniently made of injected moulded plastics, namely a bracket arm 1, a mounting block 3, and a locking slide 5.

The arm 1 includes a flat member 7, with an internal profile corresponding to that of the gutter to be supported, which in the illustrated embodiment is an ogee profile. Overhanging the front and rear upper ends of the member 7 are integral retaining lips 9, 11, under which the front and rear edges of the gutter are clipped in order to retain the gutter in the bracket arm.

The arm is stiffened by a rib 13 below and integral with the profile member 7. Integral with the upright rear portion of the profile member 7 and with the rear of the rib 13 is a locating plate 15, of which the upper region is wider than the member 7 and carries, on its rear face, a plurality of projecting horizontal ribs or teeth 17 each of saw-tooth profile, with the steeper face facing downwards in the normal position of use. In the illustrated embodiment, these lower steeper faces are substantially perpendicular to the rear surface of the plate 15.

Integral with the upper rear end of the member 7 is a rearward extension 19, extending rearwardly from the lip 11. At the rear extremity of this extension, laterally spaced rearwards from the profile member 7 and plate 15, is a pair of circular cylindrical integral lugs 21, one on each side of the extension 19.

The mounting block 3 is a vertically elongate injection-moulded plastics member of which the upper portion 23 is of substantially rectangular profile, in end view or plan, whereas the lower portion 25 is of trapezium profile. These regions 23, 25 correspond broadly to the wider upper and narrower lower regions of the plate 15 of the arm 1. The upper region 23 is of channel section, comprising a back wall 27 in which is a hole 29 for a screw or nail (Figure 2 ) , forwardly extending sidewalls 31, and inwardly extending front flanges 33 spaced by a vertical gap 35 of a width substantially equal to that of the extension 19. On the forward surface of the region 23, extending from above the lower end of the gap or slot 35 to the upper end of the lower portion 25, is a multiplicity of recessed horizontal grooves or teeth 37 having saw-tooth profiles complementary to the teeth 17, that is to say, with their steeper faces facing upwards.

The number of teeth 37 is greater than the number of teeth 17. This is a necessary condition to permit the teeth 17 to be engaged with the teeth 37 at different vertical relative positions, because the teeth 37 are formed by recessing the front face of the block 3, and therefore the teeth 17 must always be within the vertical range of the group of teeth 37. In the extreme case, there may be only a single tooth 17, however we prefer to provide more than one tooth Cthree in the illustrated case) for additional strength.

If the teeth 37 were formed by projections from the front face of the block 3, it would no longer be necessary that the number of teeth 17 be significantly less than the number of teeth 37 to permit vertical adjustment; indeed, it would be possible to use an inverse arrangement with a larger number of teeth on the plate 15 than on the block 3.

At the lower end of the slot 35 is a horizontal internal wall 39.

The lower region 25 has a front wall 41 penetrated by a vertical slot 43, oblique side walls 45, and a rear wall 47 extending over only the lower part of the height of region 25.

The locking slide 5 has an external cross-sectional profile corresponding to the internal profile of the region 25, with an enlarged lower end 49 which acts as a hand grip and as a stop. The mounting block 3 is penetrated by a vertically extending slot 51, at the upper end of which is a horizontal lip 53. When the locking slide 5 is inserted into the mounting block 3, the slot 51 is generally in register with the slot 43, but the lip 53 can adopt different vertical positions relative to the slot 43, as the locking slide 5 is free to slide vertically within the mounting block 3. A rearwardly projecting lip or tab integral with the locking slide 5 prevents the locking slide 5 from being separated from the mounting block 3, by engaging the upper edge of the rear wall 47, the shape, dimensions and flexibility of the element 55 being such that it can be pushed upwards past the wall 47 when the locking slide 5 is initially fitted into the mounting block 3, but is thereafter captive.

Integral with and projecting rearwardly from the plate 15, approximately where the width of the plate 15 reaches its narrowest, is an upwardly facing hook 57, shaped and dimensioned to extend through the slots 43, 51 when the plate 15 rests against the front walls 33, 41 of the block 3. In this position, the lip 53 of the locking slide 5 can engage the hook 57 as shown in Figures 3 and 4.

In use, the mounting block 3, preferably with the locking slide 5 already inside it, is fastened to a structure, for example a fascia or fascia board, by a single screw or nail through the hole 29, with its length vertical and region 23 uppermost. Then, the support arm 1 is offered up to the mounting block 3, so that the lugs or rollers 21 enter the upper end of the mounting block 3, behind the front walls or flanges 33, with the extension element 19 passing downwardly into the slot 35. The insertion of the arm 1 into the mounting block 3 will normally be done with the arm tilted slightly forwards and upwards as shown in Figure 1, to make insertion easier.

After the arm has been initially engaged with the mounting block 3 in this manner, it is swivelled downwardly and rearwardly to bring the teeth 17 into engagement with the teeth 37. Once the teeth are engaged, the vertical position of the arm on the mounting block 3 is defined, and in particular the arm cannot move downwards. Because teeth are provided at different levels, the arm can be set at different heights relative to the mounting block 3.

Before or as the teeth are brought into engagement, the locking slide 5 is raised by hand, so that the hook 57 enters the slots 43, 51 below the lip 53. The plate 15 then rests substantially flush against the front surface of the mounting block 3.

Finally, with the arm 1 placed at its selected height on the mounting block 3, the locking slide 5 is moved downwards or allowed to drop under its own weight, so that the lip 53 engages in the hook 57, preventing the arm 1 from moving forwards relative to the mounting block 3. By this means, the arm is positively located and cannot move in any direction relative to the mounting block 3. It can of course easily be released, if the locking slide 5 is lifted so that the lip 53 is clear of the hook 57.

Optionally, to prevent accidental release after installation, the locking slide 5 may finally be fixed into position, for example by a pin or nail inserted through it into the fascia or fascia board.

Because the final height of the arm 1 is adjustable and is not fixed by the initial fitting position of the mounting block 3, the level or fall of the gutter can easily be selected or adjusted, and errors in the initial placing of the mounting block 3 (within reasonable limits) do not make it impossible to obtain a satisfactory fall of the gutter.

The height and/or fall of the gutter can be re-adjusted after installation. The described bracket is very easy to install and, if necessary, to adjust or dismantle.

Figures 3 and 4 show the gutter support arm set respectively at its highest and lowest position relative to the mounting block 3,. the locking slide 5 being correspondingly at different heights to engage the hook 57. The permissible range of movement of the locking slide 5 is defined by the wall 39 and the top of the wall 47. The top position is such that the hook 57 can be inserted below the lip 53, in the highest possible position of the arm 1. The lowest position of the locking slide 5 corresponds to the position of the hook 57 in the lowest possible position of the arm 1, accordingly the hook is chamfered so that in this position, it will engage the lip 53 and lift the locking slide 5 as the hook is inserted through the slots 43, 51. The wall 39 also acts as a bottom stop for the extension 19, so that the arm cannot be placed in a position lower than the lowest position in which the teeth^' 17, 37 will engage satisfactorily.

It should be noted that Figures 3 and 5 show a slightly modified shape of the plate 15, compared with Figure 1. In Figures 3 and 4, the plate 15 extends upwardly to a position level with the top of the extension 19, and is chamfered at the rear of its top edge. This has been found to make it easier to fit the arm 1 initially to the mounting block 3.

The gutter bracket shown in Figures 1 to 4 can be used with any suitable shaped gutter and gutter fitting.

A common support block and slide can be used with a variety of different arms for different gutter profiles.

Figure 5 shows a gutter union suitable for use with such a bracket.

The gutter union comprises an injection moulded plastics ogee channel section body 61, with a central region 63 of profile matching the gutter and axially adjacent recesses or steps 65 to accommodate the ends of lengths of gutter. The region 63 is of a shape and size to fit into a gutter bracket as shown in Figure 1, but is substantially longer than the width of the profile member 7. Accordingly, when the union shown in Figure 5 is fitted into a bracket as shown in Figure 1, the union can move longitudinally relative to the bracket. This has a number of advantages. It enables the guttering to expand and contract longitudinally; it enables the guttering to be adjusted longitudinally; and it means that the gutter brackets do not have to be very precisely placed, in the longitudinal direction of the guttering. Adjacent the regions 65, are further enlarged end regions 67 for accommodating seal strips 69, which in use are trapped between the internal surfaces of the regions 67 and the external surfaces of the end regions of lengths of gutter inserted in the union 61. the profile of the end region of the union is shown on a larger scale in Figure 6. The region 67 has, adjacent the shoulder 71 which defines the outer side of the gutter seat and stop region 65, a shallow groove or recess 73 intended to provide axial location for the seal ring 69. For this purpose, one side of the seal strip is provided with an external lip or rib 75 of a profile matching the groove 73.

The union has at its ends overhanging lips 77, 79 to engage the edges of the gutter. To enable the union to be injection moulded without the use of collapsable cores, these lips do not overhang the deeper grooves 73, but only the portions of the seal seat region 67 extending outwardly of the grooves 73, as can be seen in Figure 5. The major part of the width of the seal strip is seated in this outer part of the region 67, in register with the lips 77, 79, so as to be compressed by the force exerted on the gutter by the lips. This arrangement provides excellent sealing while preventing axial movement of the seal strip, which with conventional seal strips can arise from thermal creep, eventually causing the seal strip to be expelled from the union in extreme cases. The seal strip can be extruded with an integral lip 75. However, Figure 6 illustrates an injection-moulded seal strip, made by co-moulding a relatively soft elastomeric central strip 81 with directly bonded stiffer edge strips 83, 85 for example of thermoplastic material. The edge regions 83, 85 are stiffer than the region 81, providing strength for the seal strip, limiting the degree to which the region 81 can be compressed, to the thickness of the regions 83, 85, and providing shape retention for the seal strip. In the embodiment shown in Figure 6, it will be seen that the locating side rib 75 is formed partly of the stiff edge strip 85 and partly of a portion of the elastomeric region 81, in order to accommodate tolerance and movement between the lip 75 and groove 73.

Figure 6 also shows the seal profile comprising three internal beads 87 and one external bead 89 on the elastomeric region 81. This profile has been found to provide particularly reliable compression sealing while permitting adequate thermal movement of the guttering.

Conventionally, lips corresponding to the lips 77, 79 make direct contact with the gutter edges. Figure 5 shows, in contrast, a seal strip incorporating at one end an integral resilient buffer or pad 91. In particular, this is formed integrally with the elastomeric portion 81 of the seal strip by injection moulding. The pad 91 conforms to the under-surface of the rear lip 77 and in use, overlies the rear edge of the gutter, while the front edge of the gutter is engaged directly under the forward lip 79 in conventional manner. The provision of this intervening resilient pad or buffer 91 makes it much easier for the user to engage the gutter under the lips, because the pad permits more movement than would a conventional stiff plastics lip contacted directly by the gutter. Because the lip itself does not have to provide both sufficient flexibility for insertion of the gutter, and sufficient rigidity and pressure to compress the seal strip between the gutter and union, the lips do not have to be moulded to the high tolerances required in conventional unions. Furthermore, the pad or buffer 91 provides a greater range of tolerance or flexibility to accommodate tolerances in the moulding of the gutter, union and seal strip, not to mention accommodation of thermal expansion and contraction.

The sealing of ogee guttering tends to present problems because of the inflected curvature of the cross-sectional profile. As a result, sealing strips of conventional manufacture, with uniform thickness along the length, cannot provide satisfactory sealing. To overcome this, the thickness of the seal strip, or at least of its elastomeric region 81, may vary along the length of the seal strip, being thicker in regions of the ogee profile at which the sealing pressure is commonly lower than elsewhere, or where gaps tend to open up in practice. This variation in thickness along the length of the seal strip can be achieved by injecting moulding the seal strip instead of extruding it as is conventional.

The guttering system described herein has numerous significant practical advantages compared with systems currently on the market. Some of these have already been described. Another is that the use of a single screw hole solely in the upper part of the bracket provides a combination of very easy installation (the screw hole being readily accessible) with maximum mechanical strength relative to the weight loading placed on the bracket.

Claims

CLAI MS

1. A rainwater gutter support bracket or gutter fitting comprising a first element engageable with a gutter, a second element adapted to be mounted on a building or other structure, these elements having complementary readily inter-engageable and disengageable locating formations adapted to define, when inter-engaged, the vertical relative positions of the elements, and manually releasable fastening means, having a first position in which the said elements are held with their said formations retained inter-engaged, and a second position in which the elements can be moved apart so that the said formations can be disengaged.

2. A gutter support bracket or fitting as claimed in Claim 1 in which the two elements can be completely separated when the fastening means are in the second position.

3. A gutter support bracket or fitting as claimed in Claims 1 or 2 in which the inter-engageable formations are so designed that the elements can be inter-engaged selectively at different relative vertical positions.

4. A gutter support bracket or fitting as claimed in Claims 1 or 2 having a single such formation on each element.

5. A gutter support bracket or fitting as claimed in Claims 1, 2, 3 or 4 in which the inter-engageable formations are horizontal teeth.

6. A gutter support bracket or fitting as claimed in Claim 5 in which the teeth are of saw-tooth profile with steeper faces arranged to prevent downward movement of the first element relative to the second element.

7. A gutter support bracket or fitting as claimed in any of Claims 1 to 6 in which the first and second elements are shaped so that they -can be relatively loosely connected to one another while remaining capable of movement such as to engage and disengage the said formations.

8 . A rainwater gutter support bracket or gutter fitting as claimed in claim 7, in which the second element is shaped to receive an upper rear portion of the first element in a manner permitting the first element to pivot forwardly relative to the second element for engaging and disengaging the said formations.

9. A rainwater gutter support bracket or gutter fitting as claimed in any of the preceding claims in which the releasable fastening means comprise a receptacle in one of the said elements, a projection on the other said element, so arranged that the said projection is received in the receptacle when the said formations are inter-engaged, and a locking member movably retained by one said element, having a first position in which it retains the projection in the receptacle, and a second position in which it permits separation of the projection from the receptacle.

10. The rainwater gutter support, or gutter fitting as claimed in claim 8 in which the said projection is provided on the rear of the first element, and the locking member is a slide carried by and movable vertically relative to the second element, having a normal rest position such as to engage and retain the said projection when received in the receptacle.

11. A rainwater gutter support bracket substantially as herein described with reference to figures 1 to 4 of the accompanying drawings.

12. A rainwater gutter fitting comprising a channel-shaped body having front and rear upper edges, clips provided on the said edges for engaging over and retaining the edges of a gutter inserted in the channel, a resilient seal element trapped between the channel and the gutter, and a resilient member underlying at least one of the said clips and arranged to be trapped between the said clip and the corresponding gutter edge.

13. A gutter fitting as claimed in claim 12 in which the resilient member is provided on an end of the seal element.

14. A rainwater gutter fitting as claimed in claim 13 in which the resilient member is a pad formed integrally with an end of the seal element.

15. A gutter fitting and seal strip, substantially as herein described with reference to figure 5 of the accompanying drawings.

16. In combination, a gutter seal strip having, in cross-section, a profile with regions of different depth on its outer side, and a gutter fitting having an internal transverse seal-receiving recess of matching profile, such that the gutter fitting recess and seal strip inter-engage in a manner resisting movement of the seal strip in the longitudinal direction of the gutter.

17. The combination claimed in Claim 16 in which the seal strip has, at one edge, an outwardly (downwardly) projecting bead or lip, engageable with the matching recess provided in the gutter fitting.

18. The combination claimed in claim 17 in which the groove and lip are placed to be at that side of the seal strip which is further from the end of the fitting.

19. The combination claimed in claim 17 or 18 in which the seal strip comprises, in cross-section, a softer region and a stiffer edge region, the said bead or lip being provided at least partly on the said stiffer edge region.

20. The combination claimed in any of claims 16 to 19, the gutter fitting having no seal- retaining formation between the seal strip and the end of the fitting.

21. The combination of a gutter fitting and seal strip, substantially as described with reference to figure 6 of the accompanying drawings.

22. A gutter seal strip comprising, in cross-section, at least two regions of different stiffness or mechanical strength namely at least one edge region of greater stiffness or strength, and at least one further region of lower stiffness but greater flexibility and compressibility.

23. A seal strip as claimed in claim 22 having two stiffer edge regions, and an intervening softer and more flexible and resilient region.

24. A seal strip as claimed in claim 22 or 23 in which the said regions are united with one another by co-moulding.

25. A seal strip substantially as herein described with reference to figures 5 and 6 of the accompanying drawings.