Roof window frame with a water draining channel

The subject of the invention is a roof window frame provided with a channel draining water from vapor condensed on the cold, external parts of the window, which water is flowing down and is collected in a recess located at the lowest element of the window frame.

The roof window frame has the form of a multipart framing, usually rectangular, fixed on an inclined roof. Along its internal circumference, the frame is provided with a faying face arranged on a single plane, below the upper external surface of the frame. Depending upon the window type, the faying surfaces of the frame are arranged along all elements of the window frame, forming of a closed loop, or are made only along the lower half of the circumference of the frame, starting at the place of the hinges.

The manufacturers of roof windows aim at achieving maximum tightness of the window when closed. Therefore modern windows are provided with venting channels and a gap-opening facility of the leaf, which safeguard the required venting of the room when the window is closed.

In winter, when the temperature of open air is much lower than the room air temperature, warm and damp inner air flows out due to infiltration or partial opening of the window, and moisture contained in the seeping out air condensates on the cold parts of the window frame and the window leaf, as well as on the bottom parts of the metallic shielding parts, which protect the window against wind, rain, and snow. Condensed water flows down on the window and is collected along the length of the bottom element of the window frame, in the recess with the faying face, and then seeps into the room. This can lead to moistening the walls and damaging the paint finish, causing distortion of parts of the window, due to their wetting, especially when they are made of wood.

In order to prevent these undesirable effects, condensed water has to be led off and its accumulation in the recess of the lower part prevented.

A roof window (WO2005/049951) is known, which is provided with circumferential draining grooves on the upper and both side elements of the window frame. The draining grooves are arranged along the external part of the tight contact surface between the leaf and the frame, while the draining grooves along the side elements of the window frame are not arranged in one plane but are bent up in their lower section, so that they are joining the upper, external surface of the lower element of the frame. Water flowing down in the side grooves flows out on the sheet metal roof covering through the upper, external surface of the lower element of the window frame.

Such an execution can be advantageously applied in window frames made of plastics using a casting technology, but not in windows manufactured by a technology applying longitudinal machining, especially wooden ones.

The window frame according the invention consists of longitudinal elements connected into a frame, usually a rectangular one. The framing, on part of its inner circumference or on its whole length, has faying faces arranged in a single plane, below the upper external surface of the frame. The faying faces of the frame mate with the corresponding faying surfaces of the frame of the window leaf and the gasket located between them. In the bottom element of the window frame, advantageously on the extension of the side faying faces, transversal through channels are made, having their inlet hole on the surface of the inner side wall of that element. The outlet hole of the channel is provided with a throating protruding out of the external side wall of the bottom element and is located above the upper surface of the rafter, so that water being drained-off flows onto the insulating foil of the primary covering, which is located beneath the proper roofing.

The roof window frame is shown in an the example of execution in the drawing, the Fig. 1 of which presents the view of the window frame with a through channel, and

the Fig. 2 a part section of the bottom element of the frame, which is provided with a through channel.

The roof window frame has the form a rectangular wooden framing, consisting of the upper element 1, the bottom element 2, and two side elements 3, connected together be means of flat dovetails.

Along the inner circumference of the frame are flat faying faces 4 arranged on one plane, below the external, upper surface of the window frame. In the bottom element 2, at the connection with the side elements 3, in the inner corners of the frame are fitted cubicoid elements 5 with a through channel 6, constituting a prolongation of the faying face 4 and inner wall 7 of the element 3.

The upper surface of the element 5 is located below the upper, external surface of the lower element 2 of the window frame. The inlet hole of the channel 6 is located on the plane of the inner wall of the side element 2, and the outlet hole is provided with a throating 8, protruding out of the external side wall of element 2, above the upper surface of the rafter.

Between the throating 8 and the external wall of the window frame a primary roofing foil is being inserted, on which condensed vapor water is let out from the window.

The element 5 is made of water and low temperature resistant material, and constitutes a part of the upper dovetail 9 of the side element 3 of the window frame.