A roof window with a diverter rail

Technical Field

The present invention relates to a roof window comprising a frame defining a frame opening, a sash, a pane element, and a covering assembly, the covering assembly comprising a diverter rail, where said pane element has an interior surface configured for facing an interior of a building and an opposite exterior surface configured for facing away from an interior of a building, where the frame comprises a top frame member and the sash comprises a top sash member, said top frame member and said top sash member extending in parallel in a length direction, and where the covering assembly comprises a top flashing member extending along the top frame member in the length direction and a top sash covering extending along the top sash member in the length direction.

Background Art

When installing windows in a roof, it is first and foremost vital to ensure that the roof window itself is watertight, and this may be particularly difficult when the inclination of the roof is either very high or very low. A special challenge relates to watertightness at the top of roof windows, where water draining off the roof surface ends up on the gutter-shaped top flashing member, from where it is directed to the sides of the window and drained off via side flashing members. When big volumes of water come off the roof above the roof window the top flashing member may overflow so that water enters between the sash and frame of the roof window.

Summary of Invention

With this background, it is therefore an object of the invention to provide a roof window by which it is possible to improve the watertightness at the top of a roof window.

This and further objects are achieved with a roof window of the kind mentioned in the introduction which is furthermore characterised in that a diverter rail extends along the top frame member in the length direction, said diverter rail having a proximal edge attached to the top frame member and an exposed diverter surface facing away from the top frame member, and projecting from the top frame member, the exposed diverter surface forming a diverter angle of 45-89 degrees with respect to a plane defined by the exterior surface of the pane.

The exposed diverter surface is exposed to wind and weather and faces away from the top frame member and hence forms a surface facing wind and water coming down off the roof above the roof window. The exposed diverter surface thus faces in a direction counter to a direction of water flow coming down from the roof above the roof window.

The angling of the diverter rail results in the formation of whirls between the diverter rail and top flashing member when big volumes of water come off the roof above the roof window. When more water comes off the roof above the roof window, these whirls have been shown to deflect the water so that water skips over the top of the diverter rail and onto the exterior surface of the pane. In this way the amount of water to be drained off via the flashing members is reduced, and the risk of water entering between the sash and frame of the roof window is also reduced.

The exposed diverter surface is a major surface of the diverter rail, hence a projection of the exposed diverter surface onto the exterior direction measures at least 10 mm, preferably at least 20 mm.

For optimum effect of the whirls, it is presently considered advantageous that a distance measured perpendicular to the exterior surface of the pane between a most exterior point on the diverter rail seen in the exterior direction and a most exterior point of the top frame member seen in the exterior direction is less than 10 mm, preferably less than 5 mm. It is, however, noted that several factors such as the design of the sash and the top sash covering and the distance between the diverter rail and the pane element measured in parallel to the exterior surface of the pane will also be of importance.

The shape of the diverter rail will have a big influence on the formation of the whirls.

In one embodiment, the exposed diverter surface of the diverter rail, forms an internal angle of 80-135 degrees with respect to an adjoining surface of the diverter rail, which adjoining surface extends away from the top frame member. In this way the diverter rail forms a channel extending in the length direction, which may help in diverting water to the sides of the window. The optimum size of the internal angle will depend on factors such as the inclination of the roof and the amount of water to be drained off, which in turn depends on factors such as climate and the area of the roof above the roof window.

In a further development of the preceding embodiment, a ratio of the diverter angle to the internal angle is in interval 0.30-0.95, preferably in the interval 0.50-0.90. Such ratios are advantageous to the formation of whirls and water diversion.

In one embodiment, the diverter rail comprises a main body extending from the proximal edge, and having a distal edge opposite the proximal edge, and a head flange projecting from the main body at the distal edge towards the top flashing member. The head flange will both contribute to the formation of the whirls and hinder overflow. As the skilled practitioner will understand, the direction toward the top flashing member is also a direction away from the top frame member. In a further development, the head flange comprises the adjoining surface to the exposed diverter surface forming internal angle.

The head flange may further project towards the top frame member, thereby forming a guiding surface for water skipping over the whirls and at least partially covering a gap between the main body of the diverter rail and the top sash covering.

The diverter rail may further or alternatively comprise a diverter flange between the proximal edge and the distal edge, said diverter flange projecting away from the top frame member. Such a diverter flange may result in the formation of primary and secondary whirls below and above the diverter flange or in the formation of whirls only above the diverter flange in the exterior direction, leaving the water below the diverter flange more calm and able to flow more freely towards the sides of the window. In a further development, the diverter flange comprises the adjoining surface to the exposed diverter surface forming the internal angle.

The diverter rail may be kept in place by being attached to the top flashing member or the top sash covering, possibly even being integral with one or them. Attached to the top flashing member or the top sash covering may for example be achieved by providing it with a bent edge adapted for receiving the proximal edge of the diverter rail.

Alternatively, or in addition, the proximal edge of the diverter rail may be inserted into a groove in the top frame member or in an interface unit attached thereto. In one embodiment, the proximal edge of the diverter rail is inserted in a bent edge of the top flashing member, which is then inserted into a groove in an interface unit.

Sealing strips and/or sealing members may be employed to waterproof the joint between the diverter rail and the top flashing member, the top sash covering, top frame member, and/or an interface unit.

As also mentioned above, the inclination of the roof will be of importance for the function of the diverter rail and the amount of water ending up on the top flashing member. To be able to use a roof window in different roofs it may be advantageous that the diverter angle is adjustable and/or that the diverter rail is detachable and/or replaceable.

In one embodiment, the diverter rail is in engagement with a sealing lip on an interface unit on the top frame member. This provides additional water-proofing by hindering water penetration along the outer side of the top frame member.

To collect and drain off any water, which may nonetheless penetrate along the outer side of the top frame member the diverter rail may be provided with a drainage gutter. This may of course also be advantageous if there is no sealing lip engaging the with diverter flange.

In one embodiment an extension element is attached to the diverter rail, preferably raising the most exterior point on the diverter rail in relation of the exterior surface of the pane element, thereby helping to lift water even further. The extension element is preferably angled in relation to the exposed diverter surface, extending bag towards the top frame member. The extension element may be a plate-shaped rail and/or may be made from metal or a polymer.

A sealing gasket may be is provided on the diverter rail and/or on the extension element, if present, and covering a gap between the diverter rail and a top sash covering, thereby hinder water penetration along an outer side of the top frame member. The sealing gasket as well as any sealing members and/or sealing lip are preferably made from one or more elastomers.

Brief Description of Drawings

In the following description, embodiments of the invention will be described with reference to the schematic drawings, in which

Fig. 1 is a perspective view of a roof window with a covering assembly;

Fig. 2 is a perspective, partially cut-away view of a top flashing member;

Fig. 3 corresponds to Fig. 2, only seen from a different angle;

Fig. 4 is a cross-sectional view of the top flashing member in Fig.2 and 3;

Fig. 5 is a cross-sectional view corresponding to a cross section along the line V-V in Fig. 1 and an enlarged detail thereof;

Fig. 6 is a cross-sectional view of the top of another roof window with a covering assembly;

Fig. 7 is a cross-sectional view of the top of a covering assembly; and

Fig. 8 is an enlargement of the detail marked VIII in Fig. 7;

Fig. 9 shows the diverter rail when in use;

Fig. 10 shows another embodiment of the diverter rail in use; and

Fig. 11 a cross-sectional view corresponding to a cross section along the line XI-XI in Fig. 1 .

Description of Embodiments

Referring initially to Fig. 1 , a roof window 1 is shown with a covering assembly 10, where the right-hand side of the top flashing member 1011 is shown in a state of delivery, before adaptation to the shape of a roofing material (not shown) used alongside the roof window.

The left-hand side of the top flashing member 1011 in the state of delivery is shown in more detail in Figs 2-4.

As may be seen, the top flashing member comprises a flange 1017, which will project substantially in parallel with the exterior surface 4e of the pane element 4 of the roof window 1 in the mounted state, and a diverter rail 103 being attached to this flange. In this embodiment, the diverter rail has a bent edge 1036 fitting over the flange 1017 on the top flashing member, but it might also be a flange of the diverter rail fitting into a bent edge of the top flashing member, or the diverter rail might be an integral part of the top flashing member.

The diverter rail 103 extends in a length direction L of the top flashing member and will thus extend along the top frame member of the roof window 1 in the mounted state.

In Fig. 5 a top flashing member 1011 and a diverter rail 103 as those shown in Figs. 2-4 are shown attached to a roof window 1 mounted in a roof structure 11 , the roof window being illustrated only by a top frame member 21 , an interface unit 8 and an insulating frame 7 and the roof structure only by a lath 111 and an underroof 113.

As is best seen in the enlargement at the top of Fig. 5, the flange 1017 of the top flashing member 1011 and the bent edge 1036 of the diverter rail 103 are inserted into a groove 85 in the interface unit 8, but it could also have been inserted into a groove in the top frame member 21 .

In the embodiments in Figs 2-5, the diverter rail 103 comprises a main body 1031 having a distal edge 1033 and a head flange 1034 projecting from the main body at the distal edge. The head flange 1034 gives the diverter rail the overall shape of the letter T, having a first section 10341 projecting towards the top flashing member 1011 (and thus away from the top frame member 21 ) and a second section 10342 projecting towards the top frame member 21.

The diverter rail 103 projects from the top frame member 21 and has an exposed diverter surface 103d forming a diverter angle A of approximately 80 degrees with respect to a plane C defined by the exterior surface 4e of the pane element 4, and the head flange 1034 comprises a surface which is an adjoining surface to the exposed diverter surface 103d and forms an internal angle B of 90 degrees with the exposed diverter surface 103d. The relationship between the diverter angle A and the internal angle B is here 0.89.

The most exterior point 103e on the diverter rail 103 seen in the exterior direction E is located at a distance D above plane C defined by the exterior surface 4e of the pane element 4.

In the embodiments shown in the drawing, the most exterior point 103e on the diverter rail 103 seen in the exterior direction E is located at level with the most exterior point 21 e of the top frame member 21 , but in some cases there may be a distance between them.

Turning now to Fig. 6 an alternative embodiment of the diverter rail 103 is shown. In this embodiment, the head flange 1034 projects only towards the top flashing member 1011 (and thus away from the top frame member 21 ) but is located on a section of the diverter rail, which is bent back towards the top frame member 21 in relation to the main body 1031. The diverter rail 103 further comprises a diverter flange 1035 projecting away from the top frame member 21 , the function of which will be described below with reference to Fig. 10. In Fig. 6 the diverter angle A is approximately 70 degrees. Internal angle B is here 110 degrees formed at the diverter flange 1035 which comprises an adjoining surface to the exposer diverter surface 103d, and the relationship between the diverter angle A and the internal angle B is 0.64.

A still further embodiment of the diverter rail 103, where the diverter angle A is approximately 60 degrees, is shown in Fig. 7. As is seen in the enlargement in Fig. 8, the joint between the bent edge 1036 of the diverter rail and the flange 1017 of the top flashing member is here sealed by a sealing strip 1037. The internal angle B is here 120 degrees, and the relationship between the diverter angle A and the internal angle B is 0.50.

In the embodiments shown, the diverter rails 103 are made from one piece of sheet metal, such as stainless steel, which has been bent into shape. It is, however, also possible to make them from two or more pieces, or to make them by other means, such as moulding or extrusion.

T urning now to Figs 9-10 the function of the diverter rails 103 is shown.

Due to the angling of the diverter rail, whirls 12 are formed between the diverter rail 103, specifically the exposed diverter surface 103d, and the top flashing member 1011 when water flow from the roof above the roof window is high. When more water comes, it will be deflected by the whirls as shown by the double-arrows and thus forced upwards over the head flange and onto the top sash covering 1021 s as shown in Fig. 10, from where it may drain onto the exterior surface 4e of the pane element. The distance D may help create this effect.

The uppermost whirl in Fig. 10 between the head flange 1034 and the diverter flange 1035 will usually only form when the water load is very high. When less water is present, the channel formed between the head flange 1034 and the diverter flange 1035 may serve as a channel directing water towards the sides of the roof window. The channel formed between the diverter flange 1035 and top flashing member 1011 may also serve to direct water towards the sides of the roof window and in some instances the flow of water in this channel may be relatively calm, while a whirl is present between the head flange 1034 and the diverter flange 1035.

For further water-proofing, the diverter rail 103 is in all embodiments shown as being in contact with a sealing lip 892 on the interface unit 8 on the top frame member 21 , and the diverter rails are all provided with a drainage gutter 1038 for draining off any water passing between this sealing lip and the diverter rail. These features are considered advantageous but not strictly necessary. The drainage gutter 1038 is seen to be formed in a part of the diverter rail 103 which is not exposed to wind and weather, whereas the exposed diverter surface 103 faces away from the top frame member and is exposed to wind and weather.

Another embodiment of the diverter rail 103 is shown in Fig. 11. Here the diverter rail is provided with an extension element 1039 extending upwards at an angle with respect to the second section 10342 of the head flange and back towards the top frame member at an angle to the exposed diverter surface 103d. In this way the most exterior point 103e on the diverter rail 103 is located higher than when using the diverter rail without the extension element, increasing the distance D and also lifting the most exterior point 103e with respect to the top sash covering 1021 s. Thereby the effect described with reference to Fig. 9 may be strengthened.

In the embodiment shown, the extension element 1039 is attached to the diverter rail by having a bent edge fitting over the first section 10341 of the head flange 1034, but other means of attachment are possible, including welding and the use of adhesives.

The extension element 1039 may extend over the entire extend of the diverter rail 103 or be shorter, for example being present only where the water load is the highest. It is also possible to provide two separate extension elements at a distance from each other on the diverter rail.

To further improve the water-proofing, a sealing gasket 10391 is provided on the extension element 1039. Here the sealing gasket is retained by being inserted in a fold on the extension element, but other means of attachment are possible, including the use of adhesives. This sealing gasket 10391 engages the top sash covering 1021 s and thus supplements the sealing already provided by the contact between the sealing lip 892 on the interface unit 8 and the diverter rail 103. In the embodiment shown, the sealing gasket has a tubular part 103911 , shown in its undeformed state, engaging with the top sash covering 1021 s. The large internal volume of the tubular part allows a large deformation and hence allows considerable movement of the extension element 1039 relative to the top sash covering with losing the sealing effect. Such movement may for example result from wind loads and/or water loads on the diverter rail and/or the extension element. Other embodiments of the sealing gasket are, however, also possible.

Even though the extension element 1039 and the sealing gasket 10391 are shown only in use with a diverter rail 103 having a head flange 1034, it is to be understood that a similar extension element and/or sealing gasket could also be used with diverter rails without head flange and/or with diverter rails having a diverter flange.

Other details of the embodiment in Fig. 11 corresponds to those described with reference to the previous embodiments.

List of reference numerals

1 Roof window

10 Covering assembly 1011 Top flashing member 1017 Flange of top flashing member 1021s Top sash covering 103 Diverter rail 103d Exposed diverter surface 103e Most exterior point 1031 Main body 1033 Distal end 1034 Head flange 10341 First section 10342 Second section 1035 Diverter flange 1036 Bent edge 1037 Sealing strip 1038 Drainage gutter 1039 Extension element 10391 Sealing Gasket

11 Roof structure 111 Lath 113 Underroof

12 Whirl 21 Top frame member 21e Most exterior point

31 Top sash member 4 Pane element 4i Interior surface of pane element 4e Exterior surface of pane element

7 Insulating frame 8 Interface unit

85 Groove 892 Sealing Lip

A Diverter angle of diverter rail B Internal angle of diverter rail D Distance C Plane defined by exterior surface of pane element E Exterior direction L Length direction