Such drainage gutters may for instance be used, when a window is to be mounted in a roof structure with an underroof.

To make room for a window to be mounted in the roof structure, the horizonal battens between the two rafters are cut through and an aperture is made in the underroof tacked to the rafters.

To prevent water from melting, penetrating drift snow or other kind of moisture from running down the upper surface of the underroof and reaching the window through the aperture, it is necessary to provide a gutter which may guide the water away from the aperture to the intact underroof away from the aperture.

This is typically done by ending a length of underroof above the window in such a way that it overlaps a length positioned below, in which an aper- ture for the window has been cut out.

The length positioned uppermost is then provided with two slots extending substantially perpendicular to the bottom edge of the underroof length along the two rafters, between which the window is positioned, such that a tongue is provided between the places where the length is attached on the respective rafters.

The gutter may be shaped in situ from the cut out tongue by bending the free end of the tongue into U- shape up in front of the mounted underroof, following which the free end is attached to a slat mounted between the rafters above the tongue.

To make this gutter function satisfactorily, a great deal of care is needed, as on one hand the gutter must have a suitable slope and on the other hand it must be so suitably tightly secured to the slat that the produced gutter neither sags in the middle nor collapses. The latter is in particular a problem in very flexible underroofs.

Alternatively, a prefabricated, substantially U- shaped gutter may be used, said gutter being mounted with a suitable slope transversely between the respect- ive rafters, one leg of the U-shape penetrating the slots in the upper membrane such that the tongue ends down in the U-shape.

In this connection the problem exists that a flexible underroof may sag, a pocket, in which water may gather, being formed behind the gutter. If suffi- cient water gathers in the pocket, it may become so heavy that it pulls the tongue up from the gutter and down behind it. This is in particular problematic in connection with very flexible underroofs.

To avoid this problem it is necessary to provide the gutter with a support in the form of a batten, which makes it possible to attach the underroof by means of nails or the like which penetrate both under- roof, gutter, and batten.

Fastening of the tongue in the gutter by adhesive tape or the like is in practice impossible on account of the prevailing environment, viz. the gutter being for one thing subjected to temperature variations from e. g.-20°C to +70°C and for the other may either be filled with water or exposed to too low air humidity.

The necessary support presents the problem that the craftsman to mount the gutter is to have a piece of wood of a suitable length at hand. This piece of wood is typically to be brought up from or fetched on the

ground, which takes costly time. Often there will be pieces of wood available for the support in the form of the battens cut out to give room for the window. These pieces of wood are, however, necessarily shorter than the distance between two rafters and thus cannot be used straight away, but have to be joined to form one support, which is also time-consuming.

As the gutter, moreover, is designed to be pene- tratable for nails or the like, partly with a view to the fastening of the underroof, partly with a view to being itself mounted on the support, the gutter is typically made from plastic or thin aluminium, for which reason it is not sufficiently strong to be self- supporting.

Moreover, a consequence of the nailing of the underroof in the drainage gutter will be that the underroof is not immediately movable. Should an undesired folding in the underroof have occurred during the nailing, then nails have to be removed first by use of tools, the folding smoothed out and the underroof nailed anew.

It is the object of the invention to provide a drainage gutter of the kind mentioned by way of intro- duction which does not suffer from the above drawbacks.

This object is met by a drainage gutter of the type mentioned by way of introduction which is charac- terized in comprising at least one holding means which, without damaging the underroof, may retain the under- roof in the drainage gutter.

In an advantageous embodiment the holding means comprises a second profile of substantially U-shaped cross section, said holding means being adapted to lockingly engage the gutter member and, in the locking engagement to retain the underroof, the underroof being

clamped between respective U-legs of the gutter member and the holding means.

This makes the fastening of the underroof in the drainage gutter simple and easy to carry out.

It is in particular advantageous if the first U- leg of the holding means is manufactured from a resil- ient and flexible material so as to allow the clamping of underroofs of different thicknesses.

It is furthermore advantageous if the second U-leg of the gutter member ends in a bending or folding facing the interior of the U-shape, and that the second U-leg of the holding means is designed for springy engagement behind the bending or the folding.

In this way a good locking is obtained between the gutter member and the holding means.

Advantageously, the second U-leg of the holding means may also end in a bending or folding.

This offers the advantage that the holding means is easy to insert and remove, for instance if the underroof is not positioned as planned in the drainage gutter. In particular this is feasible without any risk of damage to the fingers of the hands. It is, however, also feasible straight away even though gloves are worn.

In an advantageous embodiment of the drainage gutter the respective first U-legs are longer than the respective second U-legs of both the gutter member and the holding means.

In this way it is easy to mount the holding means and at the same time a considerably freedom of choice is given as to the positioning of the underroof rela- tive to the gutter member.

In another advantageous embodiment of the drainage gutter the two U-legs of the holding means are substan- tially of the same length.

In this way a holding means with a symmetrical, U- shaped cross section is obtained, such that the holding means at the mounting may uncritically be turned 180° in the longitudinal direction without any influence on its function.

In an advantageous embodiment of the invention the gutter member constitutes a telescopic element and therefore also comprises at least one third profile of substantially U-shaped cross section, said profile being adapted to longitudinally displaceable engagement with the first profile.

In yet an advantageous embodiment the gutter member and/or the holding means comprises an antislip protection. Acccording to an advantageous embodiment, this antislip protection comprises a coating of anti- slip material or, according to another embodiment, impressions in the gutter member.

Hereby the advantage is obtained that thin and/or smooth types of underroof may be more safely retained.

It is a further object of the invention to indi- cate the use of a drainage gutter which is character- ized in that it has such a rigidity that, at least in case of mounted holding means, it may be mounted in a roof structure comprising at least two rafters and an underroof laid out on top thereof without any other support than the subjacent rafters at the respective ends of the drainage gutter.

Hereby a reduction of the time required for the mounting is obtained relative to the above-referenced prior art.

The invention will now be described in detail by means of an example of an embodiment and with reference to the schematic drawings, in which Fig. 1 is a perspective view of a telescopic embodiment of a drainage gutter according to the

present invention, but without the securing member being mounted, Fig. 2 a perspective view of a holding means according to the invention, Fig. 3 a sectional view through the telescopic drainage gutter according to Fig. 1 with mounted holding means according to the Fig. 2, Fig. 4 a sectional view through another embodiment of the drainage gutter according to the invention, with mounted holding means and with retained underroof, Fig. 5 a sectional view through the drainage gutter according to Fig. 4, with mounted holding means but with a thicker underroof, and Fig. 6 an alternative embodiment of a holding means.

In Fig. 1 a telescopic embodiment of a drainage gutter according to the invention is shown in perspec- tive. The telescopic drainage gutter comprises two substantially U-shaped, elongate profiles 3 and 4, in the following termed third and first profiles, respect- ively, which are designed such that they are longitudi- nally displaceable relative to one another. By dis- placement of two profiles 3 and 4 relative to one another, the total length of the drainage gutter may be adapted to the given mounting condition without the use of tools therefor. This means in practice that the length may be adapted to the distance between the two rafters, on which it is desired to mount the drainage gutter.

Preferably, the legs 31,41 of the U-shape, in the following called the rearmost U-legs, which are to abut the rafters, designed in such a manner that they are longer than the U-legs 32,42 facing away from the rafters, said U-legs 32,42 being in the following called the foremost U-legs. This makes it easier to

mount the gutter by use of for instance nails through the rearmost U-legs 31,41. Furthermore, the placing in the gutter of the tongue cut out in the underroof is facilitated, as the tongue then rests on top of the comparatively long, rearmost U-legs and can easily be held by the fingers until a holding means 2 is mounted.

The comparatively long U-legs further make it easier to place the tongue with its usually horizontally cut lower end in the drainage gutter, which necessarily has to be mounted obliquely without the risk that the tongue does not reach far enough at one side, whereas it is too long at the other side.

The holding means 2 is shown in perspective in Fig. 2. The holding means 2 comprises an elongate, substantially U-shaped profile, in the following termed second profile, which is made from a suitable resilient material, such that the two legs of the U-shape are springy. The mounting of the holding means is carried out by pressing it down into the U-shape of the pro- files 3,4, whereby the U-legs of the holding means get into resilient abutment in the rearmost and the fore- most U-legs of the gutter members. It should, however, be noted that the resilient abutment at the rearmost U- legs will normally not be direct, but through the intermediate underroof which is to be secured. In the following the U-legs for the holding means are called foremost and rearmost in accordance with the U-legs of the profiles 3,4, on which they abut.

As will be seen from Fig. 3 both the holding means 2 and the first profile 4 are provided with respective locking means 22b, 42a to secure the holding means 2 in the profiles 3,4.

In the embodiment shown, the locking means of the first profile 4 comprises a bending or folding 42a of the foremost U-leg against the interior of the U-shape.

Correspondingly, the foremost U-leg of the holding means is bent inwards towards the U-shape such that an area 22b with a suitable rounding is provided for resiliently clamping behind the bending or folding 42a.

After the rounding, the foremost U-leg 22 of the holding means 2 is bent in the opposite direction, such that it substantially extends in the general direction of the U-leg.

Preferably, the foremost U-leg 22 of the holding means is longer than the foremost U-legs 32,42 of the profiles, such that it protrudes out above the pro- files. This makes it possible to remove the holding means 2 again without the use of tools. This is done by pressing the foremost U-leg 22 of the holding means inwards into the U-shape, such that the engagement is loosened. To ensure a good finger grip, which even by use of gloves makes this pressing-in possible, the foremost U-leg 22 of the holding means may end in a smooth bending or folding 22a. This bending leaves no sharp edges, such that the use of gloves mentioned above is not necessitated by the handling of the drainage gutter but instead by other factors like for instance the weather.

In the telescopic embodiment it is advantageous if the bending or folding 42a of the foremost U-leg 42 of the first profile 4 in addition to providing the locking means also provides an engagement with the foremost U-leg 32 of the third profile 3, such that the mutual displacement can only take place in the longi- tudinal direction of the profiles. In the same manner, the rearmost U-leg 31 of the third profile 3 may have a bending or folding 31a for engagement with the rearmost U-leg 41 of the first profile 4. It should, however, be noted that this bending or folding 31a is to face away from the interior of the U-shape.

To provide friction, such that the two profiles 3, 4 are not inadvertently displaced relative to each other, the rearmost U-leg 41 of the first profile is at the upper end provided with a slight bending 41a, such that the upper edge of the U-leg is pressed against the backside of the rearmost U-leg 31 of the third profile within the bending 31a.

In Figs 4 and 5, a non-telescopic drainage gutter 1 is shown, which gutter may, in principle, be designed completely like the first profile 4 in the telescopic embodiment according to Figs 1 and 3. Similarly, also the holding means 2 shown is identical with the one shown in Figs 2 and 3.

Furthermore, it has been illustrated in Figs 4 and 5 that the holding means 2 is designed in such a manner that it may secure underroofs 54,55 of different thicknesses.

In Fig. 4 the clamped underroof 54 is for instance a flexible underroof membrane 54 with a thickness of approximately 1 to 2 mm, whereas in Fig. 5 it is a rigid underroof sheet 55 with a thickness of for instance 5 mm.

To make this securing of different types of underroofs with different thicknesses and properties possible, the rearmost U-leg 21 in the holding means 2 is provided with a sharp bending approximately half way up the U-leg 21, such that the upper end, when the holding means has been mounted, is pressed against the underroof 54,55, which is in turn pressed against the rearmost U-leg 11 of the drainage gutter. The securing at the upper end of the comparatively long, rearmost U- leg 21, contributes to remedying the above-mentioned problems in respect of positioning a horizontally cut tongue in an obliquely mounted gutter.

In an alternative embodiment, the holding means 2 may be designed with a substantially symmetrical U- shaped cross section, viz. such that the foremost U-leg 22 is a mirror image of the rearmost U-leg 21. In this way the holding means 2 may freely be turned in the longitudinal direction without any influence on its securing function.

In the cases, where very thin underroof membranes are used, for instance foils of the type TYVEK, which have a thickness of 0.1-0.5 mm, the underroof may be placed in the gutter member such that it follows its U- shape.

In this manner the U-shaped holding means may be pressed down into the U-shaped gutter member, the underroof being thereby clamped both between the fore- most and the rearmost U-legs. In this manner an optimum securing of the underroof is ensured.

As a supplementary or alternative way to ensure optimum securing of the foil, particularly in case of thin foils, the elongate gutter member of the drainage gutter or the holding means 2 may be provided with antislip means. These antislip means may for instance be a friction coating on at least a part of the intro- verted surface of the gutter member or at least on a part of the extroverted surface of the holding means 2.

Another example of the design of antislip means is embossments in the gutter member, preferably in the form of small protrusions or impressions.

In the embodiments shown, the profiles 1,3,4 are made from 1 mm bent aluminium, or from 0.5 mm-0.7 mm spring steel or galvanized steel. These material thicknesses are sufficient for making the drainage gutter self-supporting and even walkable. By this is meant that during work on a roof structure, on which the drainage gutter has been mounted, the drainage

gutter may be trod upon without any risk of the person doing so falling dawn.

The holding means according to the embodiment shown has a length which in respect of size corresponds to the shortest lengths of the profiles, viz. the length of the profiles of the gutter member in the telescopic embodiment when they have been telescoped completely into each other. The holding means is preferably made from bent aluminium, spring steel or galvanized steel with thicknesses corresponding to that of the gutter member and contributes, when mounted, further to the strength of the drainage gutter. Holding means with a size adapted to the rafter distance in question and thus to the length of the drainage gutter may of course also be used.

In the cases, in which the strength of the drain- age gutter is less important, several holding means of shorter length may be used instead of one long, elon- gate holding means. It could in particular be the question of holding means with a length which is shorter than the height of the rearmost U-leg. In practice, they will thus be like clips. Alternatively, the holding means may in this case be designed as a spring clip as shown in Fig. 6.