The present invention relates to a window adapted for being mounted in an inclined surface of a building, said window comprising

a frame structure including a plurality of frame members and a sash structure including a plurality of sash members, where the frame structure and the sash structure each defines a substantially rectangular unit with an inner opening, a lower edge intended to face downwards in the mounted state of the window, an upper edge intended to face upwards in the mounted state of the window, and two side edges extending between the lower and upper edges, and where said edges of the frame structure meets at four corners of the window,

a pane element in connection with the sash structure and including at least two sheet elements, such as sheets of glass, separated by one or more spacer members, an interior sheet element forming an interior side of the pane element intended to face the interior of the building in the mounted state of the window and an exterior sheet element forming an exterior side of the pane element intended to face the exterior in the mounted state, each of the interior and the exterior sheet elements having a lower edge intended to face downwards in the mounted state of the window, an upper edge intended to face upwards in the mounted state of the window, and two side edges extending between the lower and upper edges,

a condensation drainage opening in the sash and/or frame structure at a lower edge of the pane element, and

at least one operator arranged at the lower edge of the frame structure on an outer side thereof opposite the inner opening.

The invention further relates to a method for draining condensation from such a window.

Windows with condensation drainage openings in the sash structure are well known in the art. One example is DE4320321A1 , where an opening is provided in a sealing gasket used between a sash bottom member and the lower edge of the pane, and where condensed water is drained off onto a covering member on the exterior surface of the sash bottom member and from there onto a flashing member. In other cases water is led away via systems of channels and openings formed in sash and/or frame members and from there onto covering and flashing members. Many of these systems work very well in structurally simple windows, but in more complex windows where for example motors or like operators are arranged on the outer side of the sash and frame structures to be concealed for the user of the window as described for example in EP2472043A1 , the drainage path too may become complex. Moreover, the system of covering and flashing members used for protecting such motors and like devices arranged on the outer side of the frame structure is also relatively complex.

It is therefore the object of the invention to provide a window with an alternative covering of an operator arranged on the lower outer side of the window and with an alternative drainage system.

This is achieved with a window wherein at least one sheet element of the pane element projects over the lower edges of the sash structure and the frame structure away from the inner opening, and which further includes a first drainage element and a second drainage element, said drainage elements being arranged so that water may drain off from the first drainage ele- ment and onto the second drainage element, where the first drainage element extends substantially in parallel with the lower edge of the interior sheet element of the pane element and has the shape of a gutter, which is arranged with the concave side of the gutter facing the lower edge of the interior sheet element, and where the second drainage element is arranged at a corner of the window and extending substantially in parallel with a side edge of the frame structure, away from the inner opening.

The projecting sheet or sheets of the pane element covers the space between the sash and frame structures and depending on the length of the projection potentially also cover the entire exterior side of the operator and like devices arranged below the frame structure in the mounted state.

The first drainage element being arranged underneath the lower edge of the pane collects any condensed water forming on the interior side of the pane. Water condensating on the part of the pane projecting over the sash and frame structures may drip directly onto the first drainage element, while water on the inner side of the sash structure reaches the first drainage element via a drainage opening in the sash structure. It is presently preferred that the drainage opening is embodied substantially as described in DE4320321A1 , i.e. as an opening in a sealing gasket used between a sash bottom member and the lower edge of the pane, but other embodiment are of course possible as will also be elaborated below.

If the amount of condensed water is low, it may simply be caught in the first drainage element and stay there until it evaporates. Usually, however, it will run along the length of the gutter and eventually reach the corners of the window. Here the water will run off the first drainage element and onto the second drainage element, which will lead it away from the pane and onto a flashing member or a surface of the building, which is resistant to water, e.g. a roofing.

The first flashing element may be formed as an open-ended gutter so that the water simply run over its edge, but it may also have one or both opposite ends partially closed and/or be provided with holes either at the ends or in the bottom of the gutter away from the ends.

To make the construction as continuous and structurally simple as possible, the first drainage element extends from one side edge of the pane to the other, and may project even further to provide an overlap with the second drainage element.

Second drainage elements being provided at both opposite ends of the first drainage element means that proper draining may be achieved regardless of any inclination of the first drainage element and other factors influencing the flow of water along the first drainage element.

In addition to being attached to the outer side of a bottom member of the frame structure, the first drainage element may also be attached to win- dow mounting brackets, which are typically positioned at the corners of the frame structure.

The first drainage element has a cross-sectional shape including three legs, a first leg extending substantially perpendicularly to the plane of the pane element and a second leg extending substantially in parallel thereto, said first and second legs forming the gutter, and a third leg extending substantially perpendicularly to the plane of the pane element and being attached to the frame structure.

The second drainage elements are preferably arranged in connection with a mounting bracket connected to the frame structure at a corner of the window, but it is also possible to attach a second drainage element directly to the frame structure, particularly if using mounting brackets, which are not lo- cated at the corners of the window.

The window system may further include a third drainage element arranged at the interior side of the pane element and extending at least partially across an exterior surface of a sash bottom member, preferably projecting over the lower edge of the sash structure to span a gap between the sash structure and the frame structure and/or between the sash structure and the first drainage element. Two third drainage elements are preferably arranged one at each side edge of the interior sheet element, where there the risk of condensation is typically the highest. The third drainage element may be arranged in continuation of an interruption of the sealing strip known for exam- pie from DE4320321 A1 so that water passing the sealing strip drains off onto the third drainage element. To secure the draining function the third drainage element is preferably provided with local distance keepers intended to come into engagement with the interior side of the pane element and prevent the intended drainage surface from sticking to the interior sheet element.

The pane element may be a standard two-layer insulating pane, but in an advantageous embodiment it is a so-called stepped pane, where the exterior sheet element is larger than the interior sheet element, so that the exterior sheet element projects further over the sash structure than the interior sheet element. Preferably, the exterior sheet element of the pane element extends across the first drainage element so that its lower edge is located on the opposite side of the first drainage element from the inner opening of the sash structure. This allows the exterior sheet element to cover the operator and other components located on the outer side of the frame structure, while the interior sheet element, which is typically the seat for condensation, ends above the first drainage element. Other advantages of using a stepped pane will be explained below.

As the ideal position of the first drainage element is often directly above the operator motor, the first drainage element may be provided with an opening through which a chain or rod of the operator may project. To reduce the risk of water entering through this operator opening, the opening is advantageously provided with upwards bent edges and the end edges of the first drainage element may likewise be provided with downwards bent edges to guide the water in the intended direction. The downwards bent edges may be formed as a local lip to concentrate and direct the stream of water.

In the following the invention will be described in closer detail with reference to the drawing where

Fig. 1 is a perspective view showing three windows installed as a group with one common covering and flashing assembly,

Fig. 2 shows one of the windows in Fig. 1 with associated flashing members,

Fig. 3 is a cross-sectional view along the line Ill-Ill in Fig. 2,

Fig. 4 shows a lower corner of a window, where the mounting brackets and most of the covering and flashing assembly have been removed,

Fig. 5 is a perspective view of a third drainage element arranged on a sash structure,

Fig. 6 is a cross-sectional view along the line IV-IV in Fig. 1 , but where side members of the sash and frame and side coverings members have been removed, and

Fig. 7 is a perspective view of a frame extension element adapted for serving as a first drainage element.

A series of three window systems, in the following also referred to as windows only, is shown in Fig. 1 and the centre window system is shown from a slightly different angle in Fig. 2. Each window system comprises a pane element 1 encased in a sash structure 2, which is connected to a frame 3. A covering and flashing assembly 4 includes a plurality of flashing members 41 - 46 used for bridging the gap between the windows and the building surface (not shown) in which they are mounted, and a plurality of covering members 51 -54 used for covering exterior surfaces of the windows. Mounting brackets 6 are provided at each corner of the window, only two being visible in Fig. 2.

In the embodiment shown the flashing members 41 -46 and the mounting brackets 6 are adapted for installation of the windows on a so-called upstand (not shown), which is a load-bearing frame construction typically formed on a roof with limited inclination as described for example in EP2472027. It is, however, to be understood that the present invention works equally well in other installation situations, where the flashing assembly and mounting brackets are of a different configuration.

Turning now to Figs 3, which shows a sectional view of the bottom parts of the centre window of Fig. 1 , the operator 7 is seen on the outer side of the frame bottom member 31 at the lower edges of the pane element 1 . The operator includes an operator housing 71 , a motor 72 and a chain 73. The chain transmits forces from the motor to a transverse element forming a yoke 25, which in the embodiment shown has a supporting function in addition to the traditional sash structure 2, but which may even provide the sole supporting function to the pane element 1 at the lower edge of the window system.

When mounting window systems in groups as in Fig. 1 it is common to make some of the windows as passive units without hinges and operators to reduce both the initial price and cost for maintenance and repairs. In a group of three windows as in Fig. 1 , the centre window will typically be an active window with operator, whereas the left and right windows will be passive but other configurations are of course possible. In such cases the space occupied by the operator housing 71 in active windows may be filled with an insulating member in the passive windows. Accordingly, the outlines of the operator housing in Figs 4 and 6 may also be seen as representing such an insulating member.

In Figs 3, 4 and 6 the pane element 1 includes two sheet elements 1 1 , 12 separated by a spacer 13. The interior sheet element 1 1 , which for safety reasons consists of laminated glass, just projects over the lower surfaces of the sash bottom member 21 and the frame bottom member 31 , while the exterior sheet element 12 projects somewhat further and covers the oper- ator 7. A pane element of this type is known as a stepped pane.

In the embodiment shown the lower edge of the interior sheet element 1 1 abuts a glazing support 14 arranged on the yoke 25. When the window is mounted with a steep inclination the provision of the glazing support 14 allows the yoke 25 to carry at least some of the weight of the pane ele- ment, thereby minimizing or even eliminating the forces on the actual sash members.

It is to be understood that the invention also applies to windows, where only one sheet element of a stepped pane element 1 projects over the sash 2 and frame 3, and to windows with a traditional non-stepped pane ele- ment. In the first case the interior sheet element 1 1 may then be arranged to abut the sash bottom member 21 as described for example in DE10059849A1 , and in the latter case the yoke 25 will be on the interior side of the interior sheet element. The use of a traditional none-stepped pane element has the advantage that this type of pane is cheaper than a stepped pane, but as will be apparent from Fig. 6 there will then be less room for the operator, or alternatively other elements of the window system would have to be designed differently. As an example the sash members could be higher to make room for the yoke, but this would make the window construction more bulky.

A bottom sash covering comprising two covering members 51 , 52 is provided at the lower edge of the exterior sheet element 12. One covering member 51 has the shape of an L and is attached with its longer leg 51 1 to the exterior surface of the exterior sheet element 12 by means of an adhesive. The shorter leg 512 of the L envelopes the lower edge of the exterior sheet element 12 and projects downwards towards a flashing member 41 , which is embodied substantially as described in EP2472027 and which will therefore not be described in further detail here. If designed appropriately, this first covering member 51 might in principle be sufficient, but in the embodiment shown, a second covering member 52 is attached to its shorter leg.

The second covering member 52 is here attached to the first covering member 51 by a snap-locking engagement with a pair of barbed legs 513, 514 thereon, but it will be understood that other means of attachment, including adhesives and even welding, are also possible. A two-part covering with a releasable interconnection is presently preferred, since it eases installation and allows removal of the second covering member 52 for maintenance of the connection between the operator chain 73 and yoke 25.

The second covering part 52 shown in Figs 3 and 6 has two legs

521 , 522 projecting towards the flashing member 41 and overlaps a frame extension element 35, which projects from the frame bottom member 31 , over the operator housing 71 and almost up to the lower edge of the exterior sheet element 12 of the pane element. This overlap means that wind blowing against the window from the left in Figs 3 and 6 will thus have to come up between the second leg 522 of the second covering member and a first leg 351 of the frame extension member 35, and turn at the distal end edge thereof in order to enter the window structure.

Here the flashing member 41 has an upstanding leg 41 1 , the end of which is held in a bend at the distal end of a first leg 351 of the frame extension element, thus providing a very reliable and water tight connection, but this need not be the case. Flashing connectors 45, which are seen most clearly in Fig. 1 , are here also provided with a leg 451 held in the bend in a similar manner as shown in Fig. 6. In this embodiment, which is shown in more detail in Fig. 7, the frame extension element 35 has the overall shape of a Z with a second leg 352 extending over the operator housing 71 substantially in parallel to the pane element 1 and a third leg 353 being used for attachment to the outer surface 31 1 of the frame bottom member 31 .

The third leg 353 is here provided with two longitudinal projections 354 and a series of openings 355, which allows it to be attached to the frame bottom member by means of screws, rivets or the like, but it will be understood that other means of attachment are possible. It is also to be understood that the third leg 353 may be left out entirely and that the second leg 352 may then be attached to the exterior surface 312 of the frame bottom member or even to the operator housing 71 if designed appropriately.

The frame extension element 35 is here, as will also be seen from Figs 3 and 7, provided with an opening 356 in a second leg 352 through which the operator chain 73 may pass, but it is also possible to simply interrupt the second leg 352 or even the entire frame extension member 35 at this place. In passive windows the frame extension element 35 may be continuous without openings or interruptions.

At the distal end of the first leg 351 the frame extension element 35 is split in two so that the two end edges 357, 358 form a longitudinal groove and a sealing element 55 is arranged with a projection 551 in the groove as shown in Figs 3 and 6. The sealing element 55 further improves the tightness of the construction by sealing the small gap left between the frame extension member 35 and the covering members 51 , 52 and/or the pane element 1 .

In the above the different elements used for water proofing the window has been described primarily with reference to the cross-sections in Figs 3 and 6, but is it to be understood that the covering and sealing elements extends substantially in parallel with the frame bottom member over substan- tially the entire length thereof. Likewise it is to be understood that separate end closure elements may be provided at the corners of the window, but the overlap of the side covering members 54 shown in Fig 1 will often be sufficient.

The structure described above with reference to the drawing provides excellent tightness, but water may nonetheless occur on the interior side, primarily due to condensation on the pane element. In addition, many other window structures are made with less focus on tightness and in such cases particularly snow may enter the structure, leading to a need for draining off melt water and the like.

For the purpose of drainage of water, attention is now drawn to especially Fig. 4. Here it is seen how the frame extension element 35 functions as a first drainage element. In the following the frame extension element will be referred to only as the first drainage element.

As mentioned above, the first drainage element is arranged underneath the lower edge of the interior sheet element 1 1 of the pane element 1 , and extends substantially in parallel with the lower edge of the interior sheet element 1 1 . Its first and second legs form as a gutter 361 , which is arranged with its concave side facing the lower edge of the interior sheet element 1 1 .

In this way the first drainage element 35 is able to collect and lead condensed water forming on the interior side of the pane element 1 , away from the interior of the window. When condensation is accumulated on the interior side of the part of the pane element 1 projecting over the sash and frame structures, it may simply drip directly onto the first drainage element 35. The water will then be led parallel along the length of the first drainage element 35 towards the end thereof. Here the water will run off the first drainage element 35, as shown by the arrow w8 in Fig. 4, and onto a second drainage element 8, which is arranged at a corner of the window and extends substantially in parallel with a side edge of the window. From here the water will be led onto a flashing member (not shown) or a surface of the building (not shown). The end of the second drainage element closest to the window frame 3 may further receive water from the side members of the sash and/or frame and/or from additional drainage elements (not shown) arranged in connection therewith.

If the amount of condensation water is low, it may simply be caught in the first drainage element 35 and stay there until it evaporates, and the first drainage element 35 should therefore be made from a material, which is ca- pable of withstanding exposure to water over an extended period of time. Examples of such materials are polymers, such as aluminium, polyvinylchloride (PVC), polyethylene (PE) or polypropylene (PP), metals, composites and combinations thereof.

Both opposite ends of the first drainage element 35 are here com- pletely open and second drainages elements 8 are provided at both ends. It is, however, to be understood that the ends may be partially closed, for example to improve insulation properties of the window, as long as the drainage is not hindered. Likewise, it is noted that the gutter 361 does not have to be formed by two straight legs, but that it may have a curved cross-sectional shape.

To facilitate draining, downwards bent edges 359 in the form of local lips projecting away from the interior side of the interior sheet element 1 1 towards a second drainage element 8 are provided at both ends at the corner where the first and second legs 351 ,352 meet. Here the two legs 351 ,352 are shown as meeting at an inclined section 361 , but to concentrate the flow this section may also be formed as a groove, which may lead the water along the length of the gutter.

The first drainage element 35 extends from one side edge of the window to the other and depending on the design of the window, it may project even further to provide an overlap with the second drainage element 8 or a first drainage element 35 of a neighbouring window. Though the invention is here described with reference to embodiments, where second drainage elements 8 are provided at both ends, it is to be understood that one may suffice, for instance if the first drainage element 35 is made and/or mounted with an inclination towards one side of the window.

As described earlier, the first drainage element 35 is formed as a Z profile, where the legs 351 , 352 is arranged such as to form the gutter 361 of the first drainage element 35, and where an opening 356 is arranged for the purpose of arranging a window operator therein. To reduce the risk of condensed water penetrating through this operator opening 356, the sides of the opening 356 is provided with an elevation 362 comprising upwards bent edges, best illustrated on Fig. 7. In this way water will be led around the opening 356, thereby preventing water from entering the space occupied by the window operator 7.

The second drainage element 8 of the window system may additionally function as a connector element which is used for securing a bottom flashing member 41 to a window frame 3. The connector element 8 may ride on the mounting bracket 6 (only illustrated in Fig. 2), which is intended for interconnecting the window frame 3 to a load-bearing structure. The connector element 8 has a substantially H-shaped cross-sectional shape, with two upper legs 83, 82 forming a gutter 81 , in which the water drained from the first drainage element 35 may be led away. A more detailed description of the connector element 8 and its connection to the frame 3 can be found in EP2472029 and in the applicants own EP application titled "A connector element for use in a flashing assembly for roof windows mounted side-by-side and a method for mounting a flashing assembly" filed on 30 August 2013. Other embodiments of the second drainage element 8, including elements attached directly to the window frame or integrated in the flashing assembly may also be used.

The second drainage element 8 may be made from plastic, such as acrylonitrile butadiene styrene (ABS), polyethylene (PE), polypropylene (PP) or polyvinylchloride (PVC), but other materials including metals and composites and combinations thereof may of course be employed as long as they are able to withstand the conditions on a roof.

Further illustrated in the embodiment of Fig. 4 is the possibility of the window system having a third drainage element 9, which is here arranged at the interior side of the pane element 1 and extending at least partially across an exterior surface of a sash bottom member 21 so that it projects over the lower edge of the sash structure and spans a gap between the sash structure and the frame structure.

As may also be seen in Fig. 5 the third drainage element here extends from a side sealing strip 93 running along the lower side of the interior sheet element 1 1 down towards the first drainage element 35 and a bottom sealing strip 96 is interrupted to give room for the third drainage element 9.

The third drainage element 9 is here provided with a groove 91 extending from the lowermost end of the side sealing strip 93 in continuation of a similar groove in the side sealing strip. Water led along the side sealing strip 93 further up the pane element 1 will thus be drained over the third drainage element 9 and onto the first drainage element 35.

In this embodiment the third drainage element 9 further comprises a drainage surface 92 arranged adjacent to the groove 91 and in connection with the bottom sealing strip 96. As may be seen the bottom sealing strip 96 is interrupted at a distance from the inner side of the side sash member 23, the side sealing strip 93 extends past the end of the bottom sealing strip 96 and both the side and bottom sealing strips overlap the drainage surface 92. Water condensating on the interior side of the interior sheet element 1 1 will typically collect at the corner of the pane element 1 and pass between the end of the bottom sealing strip 96 and the side of the side sealing strip 93 and run onto the third drainage element 9. From here it may be led towards the first drainage element 35, as illustrated by the arrow w92 in Fig. 4, and further down the gutter of the second drainage element 8 as illustrated by the arrow w8. Preferably third drainage elements 9 are arranged at each side of the pane, where it facilitates an efficient drainage along the corners of the window.

To facilitate drainage the lower end of the third drainage element 9 is illustrated with a slightly rounded shape at the end pointing towards the second leg 352 of the first drainage element 35. The third drainage element 9 may, however, also be straight or provided with two sections arranged at different angles. In Fig. 6 a different shape of the third drainage element 9 is indicated by the broken line extending down to the first drainage element 35. In this respect it is noted, that the third drainage element 9 should not be in direct contact with the first drainage element 35, since this might cause water to be drawn backwards into the structure due to capillary suction or the third drainage element 9 might become stuck to the first drainage element 35 if the window is not opened for a long time. Also with reference to Fig. 6 is it noted that the glazing support 14 shown does not extend over the entire width of the window, as is also seen in Fig. 4, and that it is therefore not in contact with the third drainage element 9, but that in other embodiments the third drainage element may be made shorter or with a different shape to avoid such contact.

The third drainage element 9 may in one embodiment as illustrated in Figs 4 and 5 furthermore comprise two local distance keepers 94, 95 intended to come into engagement with the interior sheet element 1 1 of the pane element 1 , where it prevents the intended drainage surface from sticking to the interior sheet element 1 1 .

Above the invention is described with reference to embodiments, where the third drainage element is a separate element arranged on the exterior side of the bottom sash member, but it is to be understood that it may al- so be arranged on the outer side therefore, possibly at a distance from the exterior side an in connection with a drainage hole or channel in the sash member, and/or provided as an integrated part of the sash bottom member.

The third drainage element may be made from soft polymers, such as ethylene propylene diene monomer (EPDM), EDPM cross-linked with pol- ypropylene, silicone, synthetic rubber and polyvinyl chloride (PVC) and compositions thereof, but other materials including composites may also be employed. It should be noted that different arrangement of the third drainage element 9 could also be possible and that the presence of the third drainage element 9 is not needed for the water to be drained efficiently from the win- dow.

Furthermore should it be noted that the above description of the presently preferred embodiments serves only as an example, and that a person skilled in the art will know that numerous variations are possible without deviating from the scope of the claims.