DK202470169A1

DK202470169A1 - Roof window with an adjustment system comprising a worm gear

Info

Publication number: DK202470169A1
Application number: DKPA202470169A
Authority: DK
Inventors: Galsgård Holm Michael; Øhlenschlæger Terkel
Original assignee: Vkr Holding As
Priority date: 2024-06-18
Filing date: 2024-06-18
Publication date: 2026-01-08
Also published as: EP4667694A1

Abstract

A roof window (100), particularly for installation in or on a roof surface having an inclination, comprising a primary frame (1), at least one secondary frame (2), a lifting device (10) comprising a sledge (12), a sledge guide (13), a set of arms (14, 15, 16), an adjustment system (17), and a spring assembly (11), wherein the spring assembly (11) is configured to be coupled to the sledge (12) and in that the adjustment system comprises a worm gear.

Description

DK 2024 70169 A1 1

Title of Invention

Roof window with an adjustment system comprising a worm gear.

Technical Field

The present invention relates to a roof window, particularly for installation in or on a roof surface having an inclination, comprising a primary frame, at least one secondary frame, a lifting device comprising a sledge, a sledge guide, a set of arms, an adjustment system, and a spring assembly, wherein the spring assembly is configured to be coupled to the sledge.

Background Art

Windows for installation in an inclined roof surface may be provided in a number of varieties and include more or less complicated operational structures to allow opening of the sash and to fulfil other functions, such as ventilation. Such roof windows include the type hinged at or near the middle (generally designated “pivoting roof windows”), the top-hinged type, and finally the roof windows that are top-hinged during normal operation but in which the sash is able to perform a rotating movement substantially at a centre axis near the middle of the sash, either for cleaning of the outside of the pane mounted in the sash or for providing an alternative manner of operation. Roof windows of the top-hinged type have a first axis of rotation provided by a top hinge arrangement to provide a first operational condition, whereas rotation of the sash in a second operational condition is performed by means of an intermediate frame in which the sash is hinged to provide a secondary axis of rotation. Typically, one hinge of the hinge arrangement will be located at either side of the roof window to define a substantially horizontal axis of rotation.

Examples of top-hinged windows with a second operational condition are for instance disclosed in Applicant's WO-A-89/10460, EP 0 733 126 B1, EP 1 873 323

B1, EP 2 762 665 A2, and WO 2019101281 A1. To make it possible to rotate the window sash approximately 180° to a convenient cleaning position of the pane, the

DK 2024 70169 A1 2 sash structure is connected with an intermediate frame with frame arms, which in the closed position of the window are positioned between the upper parts of the frame and sash side members, and which during normal use of the window as a top- hung window follow the sash side members.

Furthermore, the opening of a roof window and the force required to operate the window is majorly affected by the inclination of the roof, where the window is installed.

In roof windows in which the operation takes place either entirely or partially about an axis of rotation at the top, it is known to balance at least part of the weight of the movable components by means of a lifting device which includes a spring to generate the forces needed to balance the weight of the pane carrying sash. The purpose of this arrangement is to facilitate opening of the window, and the dimensions may be chosen so that the spring can retain the top-hinged sash in equilibrium in a desired opening position.

Such a lifting device is for instance disclosed in the Applicant's WO 2019/101281 Al where a spring assembly acts as a force balancing element to the pane-carrying frame by operating on a lifting arm attached to the frame.

However, although the lifting device in the above example is to some extent capable of providing the desired force balance, there is still room for improvement.

Summary of Invention

With this background it is an object of the present invention to provide the roof window with an increased design flexibility including a lifting device with the desired movement pattern and a simple structure.

This is achieved with a roof window of the kind mentioned in the introduction, which is further characterised in that the adjustment system comprises a worm gear.

In general, when referred to an exterior side, this relates to a side of a roof window in the mounted condition facing the outdoors or external side of the building. Conversely, an interior side refers to a side facing the internal side of the

DK 2024 70169 A1 3 building, i.e. typically a subjacent room including any light shaft. Terms such as “outwards” and “inwards” are directions generally perpendicular to an interior- exterior direction, taking as its base point a centre of the roof window.

The primary frame comprises side frame members extending in a length direction L, and a top frame member extending in a width direction W perpendicular to the length direction L. A height direction H extends perpendicular to the length direction L and width direction W in parallel with interior-exterior direction.

Generally, a worm gear comprises a threaded worm and a worm wheel configured to rotate around perpendicularly extending axes by arranging the thread- ing of the threaded worm between cogs of the worm wheel.

The worm gear has the potential advantage of providing a lifting device that can be adjusted from a side of the lifting device from which the user does not have to place themselves or their tools directly between the side frame member of the primary frame holding the spring assembly and the side sash member being held open by the lifting device, thereby providing a lifting device that is safer to operate.

Additionally, the worm gear has the potential advantage of reducing the size of the lifting device by allowing a user to operate the adjustment system from the side ra- ther than e.g. from between two parts of the lifting device.

The worm gear may be configured to be operated by means of a tool en- gaging with the threaded worm along the width direction and providing an adjust- ment of the adjustment system in a direction perpendicular to the width direction.

The adjustment system may further comprise a threaded adjustment screw and a bushing.

The bushing is configured to move translationally along a screw shaft of the adjustment screw when the threaded worm is rotated by means of a tool. This has the potential advantage of providing a compact adjustment system that may be ar- ranged in an opening in an arm of the set of arms, while still being accessible for the user without the user having to place themselves or their tools directly between the side frame member of the primary frame holding the spring assembly and the side sash member being held open by the lifting device.

DK 2024 70169 A1 4

The adjustment system may be configured for adjusting the position of a connection point between an arm comprised in the set arms and one of another arm of the set arms, the secondary frame, the sledge, or the sledge guide. By providing a lifting device for which the position of a connection point can be adjusted, the win- dow can be configured to be balanced for a range of roof inclinations.

The roof inclination is measured in relation to a horizontal plane. “Balanced” is to be understood as in that the lifting device provides a pulling force that balances the gravitational pull on the window in its open position and which pulls it towards a closed configuration. When the window is balanced a user can open the window to a specific opening degree without the window opening fur- ther or closing.

In this context, a connection point is defined as a pivot point between two elements which during normal operation of the roof window i.e. during opening and closing of the window, is configured to perform only a rotating movement.

The adjustment system may be configured to provide a balanced roof win- dow for roof inclinations in the range of 10 to 65 degrees by adjustment of the ad- justment system. The adjustment system is particularly well suited for providing a balanced roof window for roof inclinations in the range of 15 to 60 degrees by ad- justment of the adjustment system, such as a roof inclination of 15, 20, 25, 30, 35, 40, 45, 50, 55 or 60 degrees. It is conceivable that a balanced roof window for a roof inclination lower than 10 degrees and/or higher than 65 degrees can be achieved by changing a component of the spring assembly e.g. by changing the spring to a spring with a different spring constant.

The set of arms may be arranged in different ways to translate a pull from the spring assembly to an opening of the secondary frame. Similarly, the adjustment system may be arranged at any one such connection point, wherein the adjustment system is configured to adjust the position of the connection point e.g. by a transla- tional movement of the connection point.

The set arms may comprise a lifting arm, a sledge arm, and a push arm, wherein the sledge arm is attached to the sledge in a connection point and the lift-

DK 2024 70169 A1 ing arm in another connection point, and the push arm is attached to the sledge guide in yet another connection point and the lifting arm in yet another connection point, and the lifting arm is additionally attached to the secondary frame in yet an- other connection point. The inventors have found that the set of arms as described 5 are particularly suited for providing a balanced roof window for up to 50 degrees opening relative to a closed configuration of the roof window and particularly suited for opening degrees up to 45 degrees opening.

Each connection point is a pivot point between two elements during nor- mal operation, and the adjustment system is configured for changing the position of a connection point during adjustment of the adjustment system.

The adjustment system may be configured for adjusting the connection point between the lifting arm and the sledge arm.

The bushing may be the connection point between the lifting arm and the sledge arm, and the bushing may be configured to move translationally along the shaft of the adjustment screw providing a translational movement of the pivot point during adjustment of the adjustment device.

The worm gear may be arranged in an opening in the lifting arm.

The lifting arm may comprise a first lifting arm part and a second lifting arm part.

The first lifting arm part and the second lifting arm part may directly abut each other.

The lifting arm parts each form half a shell element which together form a closed shell element with a hollow interior.

This has the potential advantage of providing a lighter lifting device while saving material. Sufficient strength is retained in each lifting arm part by a bent edge spanning the entire circumference of the lifting arm part.

The first lifting arm part comprises at least one opening configured for re- ceiving a collar comprised in the second lifting arm part, wherein the opening and collar are configured for providing means for fixing the first lifting arm part and sec- ond lifting arm part together.

DK 2024 70169 A1 6

Other presently preferred embodiments and further advantages will be apparent from the subsequent detailed description and drawings.

Brief Description of Drawings

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

Fig. 1 is a perspective view of a roof window in an embodiment according to the disclosure;

Fig. 2 is a partial perspective side view of a lifting device of a roof window in an embodiment of the disclosure, in an open position;

Fig. 3 is a partial side view of the lifting device of Fig. 2;

Fig. 4 is a perspective view of the lifting device of Figs. 2 and 3 in an open position;

Fig. 5A is close-up view of a part of Fig. 4.

Fig. 5B shows the area from Fig. 5A of an alternative embodiment of a lifting device according to the disclosure.

Fig. 5C shows the area from Fig. 5C of yet another alternative embodiment tof a lifting device according to the disclosure.

Fig. 6 is perspective view of an adjustment system of a lifting device according to the disclosure.

Fig. 7 is a perspective view of a lifting arm of a lifting device according to the disclosure.

Fig. 8 is a back view of a lifting device according to the disclosure.

Description of Embodiments

In the following detailed description, a preferred embodiment of the present invention will be described. However, it is to be understood that features of the different embodiments are exchangeable between the embodiments and may be combined in different ways, unless anything else is specifically indicated. It may also be noted that, for the sake of clarity, the dimensions of certain components

DK 2024 70169 A1 7 illustrated in the drawings may differ from the corresponding dimensions in real-life implementations.

It is noted that terms such as “up”, “down”, “left-hand”, “right-hand”, “exterior”, “interior”, “outer”, “inner” are relative and refers to the viewpoint in question. In general, when referred to an exterior side, this relates to a side of a roof window in the mounted condition facing the outdoors or external side of the building. Conversely, an interior side refers to a side facing the internal side of the building, i.e. typically a subjacent room including any light shaft. Terms such as “outwards” and “inwards” are directions generally perpendicular to an interior- exterior direction, taking as its base point a centre of the roof window. A longitudinal direction is, if nothing else is mentioned, longitudinal along the length of a frame member of the roof window. It is to be understood that the arrangement shown in a horizontal orientation is not the normal orientation as the roof window is installed in an inclined roof.

General description of roof window

In the following, details relating to a general embodiment of a roof window 100 such as the one shown in Fig. 1 will be described. The roof window 100 is intended to be installed in or on an inclined roof surface (not shown).

The roof window 100 comprises a primary frame 1 and at least one secondary frame 2 which is moveable relative to the primary frame 1. The primary frame 1 is configured to be mounted to a roof structure (not shown) defining the inclined roof surface and is stationary once mounted. In the embodiment shown in

Fig. 1, two secondary frames are provided, namely an intermediate frame 3 and a sash 2 carrying a glazing element in the form of a pane 4. However, embodiments are conceivable in which only a single secondary frame is present, such as for instance a pane-carrying sash.

The primary frame 1 comprises a set of frame members including in this embodiment a top frame member, two side frame members and a bottom frame member. Correspondingly, the sash 2 comprises a set of sash members including a top sash member, two side sash members and a bottom sash member. While the

DK 2024 70169 A1 8 primary frame 1 and sash 2 are described as rectangular structures, some principles of the presented concepts may be applicable to other geometrical shapes as well.

In the embodiment shown, the intermediate frame 3 comprises two arms extending from the top frame member and to a position approximately at the longitudinal centre of the respective side sash member. Embodiments are conceivable in which the intermediate frame forms a coherent U-shape including arms and a cross-bar, or is substantially rectangular, i.e. including four frame members as the primary frame 1 and sash 2.

The sash 2 of the roof window 100 is openable relative to the primary frame 1 to obtain one or more open positions. In such open position(s), the sash 2 and pane 4 are moved out of the plane of the roof window 100 defined by the primary frame 1. The roof window 100 is operated using an operating assembly, here including a handle 5 at the bottom sash member configured to interact with a locking device or striking plate at the bottom frame member. Additional or alternative operating assemblies are conceivable.

The sash 2 of the roof window 100 is top-hung in at least a first operational condition which may correspond to a normal use. That is, in this first operational condition, the sash 2 is rotated about a substantially horizontal axis of rotation A at or near the top frame member and top sash member, by means of a hinge assembly comprising a top bearing 60 connecting the primary frame 1 with the secondary frame(s). In the embodiment shown in Fig. 1, the top bearing 60 connects the intermediate frame 3 to the primary frame 1, and the sash 2 is rotatable about the axis of rotation A at the top bearing 60 via the intermediate frame 3. Thus, the sash 2 is rotated about the substantially horizontal first axis of rotation A at or near the top frame member and top sash member between a closed position and an open position. The hinge assembly including the top bearing 60 will be discussed in greater details below.

In the embodiment shown, the sash 2 is able to rotate through approximately 180° in a second operational condition, about a second horizontal axis of rotation B here positioned approximately half-way between the top and

DK 2024 70169 A1 9 bottom of the roof window 100. This offers the possibility of utilising the roof window 100 as a pivoting roof window but also provides easy access to the exterior surface of the pane 4 from the interior of the building in which the roof window 100 is installed for cleaning of the window. To achieve this second operational condition, the roof window 100 is provided with a set of a pivot hinge fittings of which a sash hinge part 8 and a frame hinge part 9 of opposite side members of the sash 2 and primary frame 1, respectively, are indicated in Fig. 1.

It is however conceivable to apply some principles of the presented concepts for roof windows on different types of windows having other opening patterns.

In the following, the sash 2 will represent the secondary frames and reference will be made to the sash 2 only, even if the secondary frame structure may involve the intermediate frame 3 as shown in Fig. 1 as well.

The side frame members extend in a length direction L, and the top frame member extends in a width direction W perpendicular to the length direction L. A height direction H extends perpendicular to the length direction L and width direction W. References to the length, height, and width in relation to a lifting device 10 is to be understood as in that the lifting device 10 is arranged in the roof window as intended. Thus, the length, height, and width may also be defined according to the lifting device, such as the length direction L being defined by the sliding direction of a sledge 12 in a sledge guide 13 of the lifting device 10, as will be apparent throughout the description.

The roof window 100 is provided with the lifting device 10 to balance at least part of the weight of the movable components of the roof window 100 and facilitate operation of the window.

Lifting device

Referring now also to Figs. 2 to 4, the lifting device 10 is shown from various sides. In Figs. 2 and 3 the lifting device is shown in an open position of a roof window for a 45-degree pitch. The lifting device 10 comprises a spring assembly 11 configured to be coupled to the sledge 12. In turn, the sledge 12 is configured to

DK 2024 70169 A1 10 slide in the sledge guide 13. The sledge guide 13 comprises a first rail 131 and a second rail 132 which are both shown in Fig. 4. In Figs. 2 and 3 the first rail 131 of the sledge guide 13 is removed to improve the readability of the drawing figures.

Each of the rails 131, 132, comprises flanges configured to retain the sledge 12 in the sledge guide 13. The two rails 131, 132 together form a track of the sledge guide 13, wherein the sledge 12 is configured to slide in the track of the sledge guide.

Looking first at Figs. 2 and 3, the lifting device 10 furthermore comprises a lifting arm 14, a sledge arm 15, and a push arm 16.

The lifting arm 14 is inserted between the primary frame 1 and the sash 2 and extends between a first end 14.1 and a second end 14.2. The lifting arm 14 is rotatably connected to the sash 2 by its second end 14.2 at a distance from the top bearing 60. The lifting arm 14 is connected to the sledge guide 13 via the push arm 16. The push arm 16 is shown with a first end 16.1 rotatably connected to the sledge guide 13 and a second end 16.2 rotatably connected to the lifting arm 14 at a distance from the first end 14.1 of the lifting arm 14.

The sledge arm 15 comprises a first sledge arm part 15a and a second sledge arm part 15b arranged on the outside of the lifting arm 14. Correspondingly, the push arm 16 comprises two parts located on the outside of the lifting arm 14 of which one push arm part 16a is shown in Fig. 2.

Even though only a single lifting device 10 for one side of the roof window is shown, it is understood that a similar lifting device may be arranged on the other side of the roof window as well. By having a lifting device 10 installed on each side frame member an even lift of the sash is provided.

To adjust the roof window 100 according to a specific roof inclination for a selected spring assembly 11, the lifting device 10 further comprises an adjustment system 17.

The adjustment system 17 is connected to the sledge 12 and in turn to the spring assembly 11 by means of the sledge arm 15. The sledge arm 15 extends between a first end 15.1 which is rotatably connected to the sledge 12 and a second end 15.2 which is connected to the adjustment system 17 (shown in Fig. 3).

DK 2024 70169 A1 11

The adjustment system 17 is also connected to the lifting arm 14, and the connection between the sledge arm 15 and the lifting arm 14 via the adjustment system 17 will be described in more detail in the following.

First, the general functionality of the lifting device 10 will be described in some detail. In Figs. 2 to 4, the sledge 12 is coupled to the spring assembly 11 which is arranged to exert a force on the sledge 12 and thereby act as a force balancing element. The sledge 12 may be uncoupled from the spring assembly 11. This may, as an example, be an advantage during installation of the roof window where a spring force acting on the sledge 12 may make it difficult to handle the roof window. In the cases where the lifting device 10 is installed in the roof window according to its intended use, the sledge 12 and the spring assembly 11 are initially in an uncoupled state. The spring assembly 11 and the sledge 12 are then coupled by opening the roof window resulting in the sledge 12 sliding towards a coupling device such as a hook 11.1 attached to the spring assembly 11. Such a coupling may for example be realised by the sledge 12 comprising a hook plate 12.1 inserted into side flanges of the sledge 12 for coupling the sledge 12 to the spring assembly 11. Opening the roof window results in the sledge 12 engaging with the hook 11.1 and once the roof window is subsequently closed, the sledge 12 will slide in a direction away from the spring assembly 11 towards the top bearing 60 of the roof window while the spring assembly 11, now coupled to the sledge 12, will exert a pulling force on the sledge 12 and provide a resistance against the closing of the roof window, thereby biasing the spring assembly 11. The pulling force of the spring assembly 11 and the weight of the roof window are preferably balanced such that the roof window can be positioned in an open position without forcing it to close due to its own weight or forcing it to open further due to the pulling force applied by the spring assembly.

This balance is affected by the inclination of the roof that the roof window is installed in.

The configuration of the spring or springs in the spring assembly 11 may be dependent on a specific roof inclination. If the roof window is installed on a roof with a roof inclination different than the intended inclination, the spring force from

DK 2024 70169 A1 12 the spring assembly 11 acting on the sledge 12 will not balance the weight of the roof window. In one example, the spring assembly 11 may exert too much force on the window thereby forcing the window to open further. In another example, the spring assembly may be too weak, and the window will close due to its own weight.

In both cases, the window may be difficult for the user to operate and potentially hazardous. To easily adjust the roof window according to roof inclination, the adjustment system 17 is used. The adjustment system 17 can be used to adjust the roof window for roof inclinations in the range of 15 to 60 degrees.

As previously mentioned, the top sash member and top frame member are connected by a hinge assembly at least in the first operational condition. A top bearing fitting 6 facilitates this connection. The top bearing fitting 6 comprises a frame attachment section 6.1 a guide attachment section 6.2 extending from the frame attachment section 6.1, as best seen in Fig. 5A. The top bearing 60 is connected to the frame attachment section 6.1. The guide attachment section 6.2 comprises means for attaching the top bearing fitting 6 to the sledge guide 13. The sledge guide 13 is securely fixed to the side frame member the top bearing fitting 6 facilitates the connection between the sash and the frame via the sledge guide 13.

In Figs. 2 to 5 the top bearing fitting 6 is arranged between the first rail 131 and second rail 132 of the sledge guide 13. The top bearing 6 is also fixed to both rails 131, 132, which provides an even load transfer from the spring assembly 11 to the top bearing 6 through the sledge guide 13. However, the lifting device 10 is configured for a selection of different top bearing fittings 6 that serves different purposes, thereby allowing the lifting device 10 to be installed in different types of windows. Fig. 5B shows an alternative top bearing fitting 6' which is only attached to the second rail 132. This top bearing fitting can e.g. be used for retrofitting other window models with a lifting device according to this disclosure. Fig. 5C shows the lifting device 10 from Fig. 5A modified with yet another alternative top bearing fitting 6”, where the top bearing fitting 6” comprises a hook element 6.3 providing additional attachment to the primary frame 1. This top bearing fitting 6” can e.g. be used when the roof window is installed with a heavy sash such as a 3-layered pane

DK 2024 70169 A1 13 carrying sash. A top bearing fitting that is attached only to the first rail 131 may also be envisioned.

Adjustment system with worm gear

In the embodiment shown in Figs. 2 to 4, the adjustment system 17 is configured to adjust the roof window 100 to a specific roof inclination by changing the relative position of a connection point between the lifting arm 14 and the sledge arm 15.

In the embodiment shown, the connection point is a bushing 17.1. In this context, a connection point is defined as a pivot point between two elements such as between the lifting arm and the push arm, which during normal operation of the roof window i.e. during opening and closing of the window, is configured to perform only a rotating movement. The adjustment system is configured to perform a translational movement of the connection point during adjustment of the adjustment system. In principle, the adjustment system may be configured to perform a translational movement of any one or more connection points between any one of the sledge 12, sledge arm 15, lifting arm 14, sash 2, or push arm 16.

The adjustment system 17 comprises an adjustment screw 17.2 with a threaded screw shaft 17.3, a worm wheel 17.4, and a screw top 17.5, as best shown in Fig. 6. The adjustment system 17 further comprises a threaded worm 17.6 coupled to the adjustment worm wheel 17.4. The threaded worm 17.6 and the worm wheel 17.4 forms a worm gear configured to allow adjustment of the adjustment system 17 from a side of the lifting device from which the user does not have to place themselves or their tools directly between the side frame member of the primary frame holding the spring assembly and the side sash member being held open by the lifting device i.e by inserting a tool in the threaded worm 17.6 from a direction parallel to the width direction W, as indicated by the arrow in Fig. 5A, said tool being configured for rotating the threaded worm 17.6 around an axis extending in the width direction w, thereby rotating the worm wheel 17.4 and screw shaft 17.3 around an axis perpendicular to the width direction resulting in a translational movement of the bushing 17.1, as indicated by the arrows in fig. 6.

DK 2024 70169 A1 14

The first end of the sledge arm 15.1 is coupled to the bushing 17.1 and the second end 15.2 of the sledge arm 15 is rotatably fixed to the sledge 12. The adjustment system 17 is adjusted by rotating the adjustment screw 17.2 such that the bushing 17.1 moves along the length of the screw shaft 17.3 thereby changing the position of the bushing 17.1 and thereby the connection point between the lifting arm 14 and sledge arm 15. This change in position shifts the weight distribution of the lifting device making it possible to adjust the force balance according to the roof inclination.

The lifting arm 14 comprises an opening 14.3 in proximity to its first end 14.1 to accommodate the adjustment screw 17.2. This opening 14.3 is rectangular- shaped in this embodiment. The worm wheel 17.4 is accommodated in a separate opening (not indicated) in the lifting arm 14. In the embodiment shown, the adjustment screw 17.2 is connected to the lifting arm 14 via the screw top 17.5.

Structure — asymmetrical configuration and material/resource savings

As indicated in Fig. 2, the lifting arm 14 comprises two lifting arm parts 14a and 14b. The lifting arm parts 14a, 14b are fitted together to move as a single lifting arm 14. The lifting arm parts 14a, 14b are formed from metal plates with a thickness of 1.5 mm. As best shown in Fig. 7, the lifting arm part 14a comprises a plurality of openings 14.4 each configured for receiving a collar 14.5 from lifting arm part 14b.

The lifting arm part 14b and collars 14.5 are uniformly formed from the same metal plate. Each collar has a collar height larger than the thickness of the lifting arm part 14a. To secure the lifting arm parts to each other, each collar 14.5 is inserted in the corresponding collar receiving opening 14.4 until a part of the collar 14.5 extends from the collar receiving opening on the opposite side from which it was inserted.

The extending parts of the collars are deformed in a manner that restricts the collars from being retracted from the openings. The lifting arm parts 14a, 14b are thereby fitted together without the use of rivets and the combined surface area of contact between the two lifting arm parts is increased, which reduces wear and tear on the respective parts.

The shape of the lifting arm parts 14a, 14b and the position and form of the

DK 2024 70169 A1 15 openings 14.4 have been carefully selected to optimize strength properties and reduce material consumption. The lifting arm parts 14a, 14b, directly abut each other, and each lifting arm part forms half a shell element which together form a closed shell element with a hollow interior. Sufficient strength is retained in each lifting arm part by a bent edge spanning the entire circumference of the lifting arm part while reducing the total weight and material consumption of the lifting device.

Turning to Fig. 4, the lifting device of Figs. 1 — 3 is shown from a different angle with both rails 131, 132 of the sledge guide 13 being visible.

The first rail 131 extends substantially the entire length in a length direction | of the side frame member to which the lifting device is attached. The first rail 131 is formed from a metal plate having a thickness of 1 mm. The first rail 131 is firmly fixed directly to the side frame member and forms part of a side frame reinforcement element. The first rail 131 forming part of the sledge guide 13 and part of the side frame reinforcement serves at least three purposes. Firstly, by having the first rail 131 as a side frame reinforcement element, a separate frame reinforcement element can be dispensed with compared to the wooden roof windows in production today which have a separate metal reinforcement plate situated at the exterior frame side, thereby reducing the material consumption of the roof window. Secondly, the first rail 131 can be arranged closer to the side frame member of the primary frame compared to windows with a separate reinforcement element arranged between the lifting device and the side frame member, thereby reducing the torque on said side frame member. Thirdly, the combined width of the lifting device and side frame reinforcement in the width direction W is reduced making the side sash frame less bulky.

The second rail 132 is here substantially shorter than first rail 131 and extends the travelling length of the sledge when the window moves from a closed configuration to a completely open configuration. The second rail 132 is formed from a metal plate having a thickness of 1 mm.

The width of the lifting device 10 in the width direction W from the first rail 131 to the second rail 132 is substantially 30 mm.

DK 2024 70169 A1 16

Turning now to Fig. 8, the lifting device 10 from figs. 2 — 4 is shown from an end of the lifting device 10 looking in the length direction L along the rails 131, 132 of the sledge guide 13. The top bearing is arranged at a distance from the first rail 131 and second rail 132 by means of spacers 18. The top bearing fitting 6 is arranged between the first rail 131 and second rail 132 and is arranged closest to the second rail 132. The top bearing fitting 6 is arranged in a plane P defined by the height direction H and length direction L. Correspondingly, the set of arms and sledge are arranged symmetrically with respect to the plane P. By arranging the set of arms, top bearing fitting 6 and sledge 12 closest to the second rail 132, there is sufficient space for installing two roof windows as indicated by a spring assembly 11’ of a neighbouring window, each roof window having a lifting device 10 according to the disclosure, next to each other, while still having room for roof cover elements covering the sash and frame elements.

DK 2024 70169 A1 17

List of reference numerals 1 primary frame 2 secondary frame / sash 3 secondary frame / intermediate frame 4 pane operating assembly / handle 6, 6, 6” top bearing fitting 6.1 frame attachment section 6.2 guide attachment section 8 sash hinge part 9 frame hinge part lifting device 11, 11 spring assembly 11.1 hook 12 sledge 12.1 hook plate 13 sledge guide 14 lifting arm 14a first lifting arm part 14b second lifting arm part 14.1 first end of lifting arm 14.2 second end of lifting arm 14.3 opening for adjustment screw 14.4 openings for collars 14.5 collar sledge arm 15a first sledge arm part 15ab second sledge arm part 15.1 first end of sledge arm 15.2 second end of sledge arm 16 push arm 16a first push arm part 16.1 first end of push arm 16.2 second end of push arm 17 adjustment system 17.1 bushing 17.2 adjustment screw 17.3 screw shaft 17.4 worm wheel

DK 2024 70169 A1 18 17.5 screw top 17.6 threaded worm 18 Spacer 60 Top bearing 100 Roof window 131 First rail of sledge guide 132 Second rail of sledge guide

A First axis of rotation

B Second axis of rotation

L Length direction

W Width direction

H Height direction

P Plane

Claims

DK 2024 70169 A1 19 Claims

1. A roof window (100), particularly for installation in or on a roof surface having an inclination, comprising a primary frame (1), at least one secondary frame (2), a lifting device (10) comprising a sledge (12), a sledge guide (13), a set of arms (14, 15, 16), an adjustment system (17), and a spring assembly (11), wherein the spring assembly (11) is configured to be coupled to the sledge (12), characterized inthat the adjustment system comprises a worm gear.

2. A roof window according to claim 1, wherein the adjustment system (17) is configured for adjusting the position of a connection point between an arm com- prised in the set arms and one of another arm of the set arms, the secondary frame, the sledge, or the sledge guide.

3. A roof window according to any one of the preceding claims, wherein the set of arms (14, 15, 16) comprises a lifting arm (14), a sledge arm (15), and a push arm (16), wherein the sledge arm (15) is attached to the sledge (12) and the lifting arm (14), and the push arm (16) is attached to the sledge guide (13) and the lifting arm (14), and the lifting arm is additionally attached to the secondary frame (2).

DK 2024 70169 A1 20

4. A roof window according to claim 3, wherein the adjustment system is configured for adjusting the connection point between the lifting arm (14) and the sledge arm (16).

5. A roof window according to any one of claims 3 to 4, wherein the worm gear is arranged in an opening (14.3) in the lifting arm (14).

6. A roof window according to any one of claims 3 to 5, wherein the lifting arm (14) comprises a first lifting arm part 14a and a second lifting arm part 14b di- rectly abutting each other.

7. A roof window according to any one of claims 3 to 6, wherein the first lifting arm part (14a) comprises at least one opening (14.4) configured for receiving acollar (14.5) comprised in the second lifting arm part (14b), wherein the opening (14.4) and collar (14.5) are configured for providing means for fixing the first lifting arm part (14a) and second lifting arm part (14b) to- gether.