GB2250042A - Seal for gutter - Google Patents

Abstract

A joint between a gutter fitting 2 and a gutter 4 is sealed by means of a resilient sealing strip 6 and a groove in the gutter fitting 2. The sealing strip 6 projects by a greater amount in an intermediate portion of the groove than in the end portions of the groove. The gutter fitting comprises two clips 12, which engage respective edges of the gutter portion 4; thus compression of the sealing strip is greatest at the intermediate portion. The seal can also be used between two gutter fillings. <IMAGE>

Description

SEAL This invention relates to a seal for sealing joints between combinations of rainwater guttering and associated fittings.

Many conventional seal systems for plastics rainwater guttering incorporate a polymer or elastomer seal in a groove moulded into a plastics fitting. This groove and seal are normally of constant depth and extend over virtually the entire cross-sectional length of the fitting. Each fitting further includes a static retaining clip or lip located at each end of each groove.

Upon assembly a length of guttering is inserted into a fitting and the cross-sectional profile of the guttering is capable of limited flexing for adapting to the inner cross-sectional profile of the fitting. The clips are provided so as to act on the respective adjacent edge of guttering, once inserted into the fitting, and thereby retain the guttering.

Different samples of plastics guttering generally have varying dimensions due to tolerances in manufacturing processes. As a result of these tolerances the cross-sectional length of the guttering varies and different pieces of guttering will adapt to a fitting to different degrees.

In practice, once a length of gutter is inserted into the fitting, the action of the clips causes it to compress the seal which is located between the outer surface of the guttering and the inner surface of the fitting. In the case of a gutter having a half-round profile, for instance, the compression of the seal at the sides of the fitting is relatively constant, even with guttering of different cross-sectional lengths, because the degree of compression at the sides can be controlled by the shape of the retaining clips used.

Furthermore, leakage at the sides is rarely a serious problem.

Preventing leakage at the base of the gutter is however very important, and this requires a certain minimum degree of compression of the seal by the guttering. To ensure that there is always adequate compression of the seal under the bottom of the guttering, at a tolerance corresponding to the shortest cross-sectional profile length of the guttering, would mean that at the opposite tolerance, namely maximum cross-sectional length of the guttering, it would become difficult or even impossible to fit the guttering inside the fitting under the retaining clips, the positions of which are fixed.

Similar considerations apply to the tolerances arising in the manufacture of the fittings. Conversely, ensuring that the guttering can always be easily inserted in the fitting and under the clips has the result that, at the tolerance corresponding to minimum cross-sectional length of the guttering (or maximum cross-sectional length of the fitting) there will be insufficient compression between the base of the guttering and the seal, and leakage will arise. As a result, conventional half-round and similar gutters not uncommonly leak at the base, particularly after they have been in use for some time, with relative movements caused in use by temperature changes accentuating any initial looseness at the seal.

These problems are not only experienced with gutters having a half-round profile. Almost any plastics rainwater guttering which uses this sort of seal is susceptible to an inhomogenous quality of sealing around the gutter profile and will demonstrate better sealing at certain points of the gutter profile than at others.

Of particular note, in this respect, is guttering whic has a U-shaped profile, a so-called "ogee" profile, a quarter round profile or a square profile.

A gutter system having an ogee profile can be particularly difficult to seal due to its complex profile (consisting of a lower concave arc which inflects into a convex arc which then inflects into an upper concave arc) and the associated manufacturing tolerances. It has been found that an ogee profile is particularly susceptible to leakage about the inflection between the convex arc and the upper concave arc. This is because with normal manufacturing tolerances it is almost impossible to produce guttering or gutter supports which have accurately consistent profiles in this region. It is not uncommon for guttering having an ogee profile to leak at this part of a seal.

The present invention sets out to provide a rainwater seal which allows guttering to be easily connected to fittings and effects a reliable watertight seal when connected.

According to the present invention there is provided so combination, a sealing strip and a gutter fitting adapted to receive a gutter portion or a portion of a second gutter fitting to fit closely within the first gutter fitting; the said gutter fitting comprising a groove extending over substantially the entire inner cross-sectional length of an inner surface of the said first gutter fitting, and further comprising two clips comprising abutment surfaces, a respective said cttp being disposed adjacent each end of the said groove lN such a position as to engage respective edges of tre gutter portion or the second gutter fitting, causing the said sealing strip to be compressed between the said first gutter fitting and the said gutter portion or the said portion of the said second gutter fitting; the said sealing strip being disposed in the groove and projecting therefrom relative to the inner surface of the fitting by a greater amount in an intermediate portion of the groove than in the end portions of the groove.

In one embodiment of the invention the groove is deeper at the end portions thereof than in the intermediate portion thereof and the sealing strip is of substantially constant cross-section along its length.

In another embodiment of the invention the groove is of constant depth and a filler piece is inserted in the groove between a bed of the groove and the sealing strip. The filler piece is adhered in place or is resilient (eg of rubber), to prevent leakage between itself and the bottom of the groove.

In another embodiment of the invention the sealing strip has a greater thickness in a portion thereof for location in the intermediate portion of the said groove than in a portion thereof for location in one of the ed portions of the groove.

Generally, an embodiment of the invention provides relative configurations of a sealing strip and its respective accommodating groove in a gutter fitting which reduce leakage throughout the whole of the gutter profile. The thickness of the strip or the depth of the groove can be made to vary in as many places as necessary, thus even improving the quality of seal for a complicated gutter profile such as an ogee profile, which could otherwise have several regions susceptible to leakage about the extent of its cross-sectional profile.

The present invention will be described by way of example with reference to the accompanying drawings in which: - Figure 1 is a perspective view of a seal incorporated in a gutter end fitting and sealing a join between a stop end fitting and a portion of gutter; Figure 2 is a plan view of part of a gutter fitting; Figure 3 is a section taken along A-A in figure 2; Figure 4 is a view of part of the gutter fitting shown in Figure 2 viewed in the direction of the arrow C; Figure 5 is an enlarged view of a detent means which forms part of the gutter fitting shown in Figure 2; and Figure 6 corresponds to part of a section along the line B-B of Figure 2 but additionally showing a sealing strip fitted into a groove.

The illustrated embodiment of the present invention is a seal formed by a gutter fitting 2, a length of gutter 4 and a sealing strip 6.

The gutter 4 is part-circular in cross-section and is moulded from a resilient plastics material, such as PVC.

The gutter fitting 2 is in the form of a gutter stop end and has a circularly arcuate inner surface 8. A groove 10 is formed in the inner surface 8 of the fitting and extends over substantially the entire inner cross-sectional length. At each end of the groove 10 a detent clip 12, which has an abutment surface 14 defining the respective end of the groove, is disposed so as to be integrally formed with the edge of the inner surface of the fitting and project radially inwardly.

The abutment surface 14 extends across the full width of the groove 10 from a point within the innermost side of the groove 10 past the outermost side of the groove to the open end 11 of the fitting into which the gutter is to be inverted. The distal end 13 of each detent clip 2 further includes a retention lip 16. The retention lip extends along the length of the underside of the detent clip 12 in a direction perpendicular to the groove but does not extend over the part of the detent clip directly overlying the groove 10.

A resilient polymer sealing strip 6 is located within the groove 10 and extends from close to one detent clip 12, along the length of the groove 10, to a point close to the second detent clip 12. The sealing strip 6 is substantially I-shaped in cross section, however cross-sections in the form of an H or a figure of eight may be successfully used. The sealing strip is of constant cross-section and can be made by conventional extrusion.

The depth of the groove 10 varies along its length, being deeper at its ends 20 than in the centre 22 which defines its shallowest region. The change in depth is gradual with distance from the centre of the groove 10.

The distance d shown in Figure 2 viz the groove depth at its ends is therefore greater than the depth s at the groove base, shown in figure 3.

An example of a fitting which has been found to be particularly effective has an inner cross-sectional diameter of 115mm. The groove has a depth of 4. ohm n a central portion, disposed at the base of the fitting, and a groove depth of 5.0mum at the end portions of the groove, disposed at respective sides of the fitting.

As a result of the difference in the depth of the groove 10, the sealing strip 6 projects from the inner surface 8 of the fitting by a greater amount in the region of the base 22 of the groove than it does in the region of the ends 20 of the groove.

The relationship between the depth of the groove 10 at the ends 20 of the groove and the depth of the groove in the centre 22 is selected to reduce the compression of the sealing strip 6 at the ends to the minimum value which corresponds to that experienced at the base of the fitting, as caused by a gutter of the minimum cross-sectional length.

The variation in depth of the groove facilitates the fitting of a length of gutter 4 into the fitting 2 because the stress exerted by the sides of the gutter upon the fitting is reduced for a given cross-sectionai length of gutter. The above described reduction in stress is accompanied by a corresponding increase in stress at the base of the fitting in the region of thn centre 22 of the groove 10. This increase in stress has the dual effect of causing greater compression of the sealing strip in the region of the centre 22 of the groove 10, thereby effectively preventing leakage and also providing improved ease of fitting due to reduced friction at the edge of the gutter.Although the compression of the sealing strip 6 at the ends 20 at the groove 10 may be much lower than in known arrangements, the increased compression in the centre of the strip 6 means that the seal does not leak.

The gutter is fitted into the fitting by simply slotting into the fitting in a direction perpendicular to the length of the seal 6. The action of the gutter edges against the retaining clips and the compression of the seal serve jointly to hold the join together.

The seal may also be used for effecting a seal between fittings in a gutter system. Furthermore, the fitting can be any appropriate fitting such as a connector for a down pipe or running outlet, a union to effect a joint between two lengths of gutter, an angle portion or a stop end outlet, for example.

Furthermore, each seal can comprise a plurality of spaced parallel grooves such as the one described above.

A seal groove of varying depth as described above can due produced relatively easily by minor modification of conventional injection moulding equipment.

Because of the presence of the clips 12, a conventional fitting as illustrated is normally made by injection moulding using a collapsible core to produce the groove, the core comprising a central member which forms the base region of the groove, together with a pair of moveable wings which form the end regions of the groove and the undersides of the clips. To produce a groove of which the depth is greater at its ends, it is only necessary to modify slightly the wings and/or the central member of the core, without affecting the rest of the mould tooling.

Rather than having a groove of varying depth as described above, the fitting could comprise a groove of constant depth and also include a tapered insert which fits into the groove between the bed of the groove and the sealing strip. Such an insert has the effect of raising the bed of the groove in the centre. Such an insert can be used to adapt existing fittings; however the insert is an additional component, which would lead to increased production costs and be more time-consuming to manufacture. The insert must itself prevent leakage, eg by being resilient or by being adhered in place.

Alternatively, the sealing strip itself can be made to have tapered thickness, thereby giving rise to the same differences in projection from the inner surface of the fitting described above, but without the need for a groove of varying depth. Typically, the sealing strip would have a relatively thicker cross-section in a central portion and a relatively thinner cross-section at each end portion. However, it would be difficult to form such a sealing strip by extrusion and it would, therefore, be necessary to resort to injection moulding, at a penalty of increased manufacturing costs.

While the invention has been described in relation to half-round guttering, it is also applicable to guttering of other profiles eg quarter round, ogee and square.

Claims (16)

Claims

1. In combination, a sealing strip and a gutter fitting adapted to receive a gutter portion or a portion of a second gutter fitting to fit closely within the first gutter fitting; the said gutter fitting comprising a groove extending over substantially the entire inner cross-sectional length of an inner surface of the said first gutter fitting, and further comprising two clips comprising abutment surfaces, a respective said clip being disposed adjacent each end of the said groove in such a position as to engage respective edges of the gutter portion or the second gutter fitting, causing the said sealing strip to be compressed between the said first gutter fitting and the said gutter portion or the said portion of the said second gutter fitting; the said sealing strip being disposed in the groove and projecting therefrom relative to the inner surface of the fitting by a greater amount in an intermediate portion of the groove than in the end portions of the groove.

2. A combination according to claim 1, wherein the sealing strip and groove are so designed that, in use, the said sealing strip is compressed by said gutter portion or said portion of said second gutter fitting by substantially the same degree over substantially its entire length.

3. A combination according to Claim 1 or 2, wherein the said intermediate portion is the base portion of an arcuate portion.

4. A combination according to claim 1, 2 or 3 wherein the said groove is deeper at the end portions thereof than in the said intermediate portion thereof and the sealing strip is of substantially constant cross-section along its length.

5. A combination according to claim 1, 2 or 3 further comprising filler means, wherein the said groove is of substantially constant depth and the said filler means is inserted in the said intermediate portion of the said groove between a bed of the groove and the said sealing strip.

6. A combination according to claim 5, wherein the sad filler means is adhered in place in the groove.

7. A combination according to claim 5 or 6, wherein. the said filler means is resilient.

8. A combination according to claim 1, 2 or 3, wherein the said sealing strip has a greater thickness in a portion thereof for location in said intermediate portion of the said groove than in a portion thereof for location in one of the said end portions of the said groove.

9. A gutter fitting and seal substantially as herein described with reference to the accompanying drawings.

10. A sealing strip for a gutter fitting, comprising an intermediate portion having a relatively greater cross-sectional thickness than an end portion of the sealing strip.

11. A sealing strip according to claim 10, wherein in use the said intermediate portion thereof locates in an arc in a groove in a gutter fitting into which the sealing strip is to be fitted.

12. A sealing strip for a gutter fitting according to Claim 10 and substantially as herein described.

13. A gutter fitting comprising a groove for receivlng a sealing strip and extending over substantially the entire inner cross-sectional length of an at least partially arcuate inner surface of the said gutter fitting and retaining clips disposed at each end of te said groove; the said groove being deeper at end portions thereof than in an intermediate portion thereof,

14. A gutter fitting substantially as herein described with reference to figures 3 and 4 of the accompanying drawings.

15. A filler strip for insertion between a sealing strip and a groove, the said groove being formed within a gutter fitting and extending over substantially the entire inner cross-sectional length of an inner surface of the said gutter fitting; the said filler strip 'serving, in use, to cause the said sealing strip to project from the said groove relative to the inner surface by a greater amount in an intermediate portion of the groove than in the end portions of the groove.

16. A filler strip for insertion between a sealing strip and a groove in a gutter fitting substantially as herein described.