FITTING FOR A REVERSIBLE STRUCTURE AND A REVERSIBLE WINDOW STRUCTURE COMPRISING A

FITTING

The current invention relates to a fitting for a reversible window structure having a window frame, a window sash and a window pane arranged in said window sash. The fitting comprises a first link, a second link and a third link. The first link has a first connection point connectable to the window frame in the upper portion of the window frame and a second connection point connected to a first connection point of the second link arranged in the middle portion of the second link. The second link also has a second connection point connectable to the window sash at a pivot point located in the middle portion of the window sash and a third connection point connected to the third link. And the third link has a first connection point connectable to the window frame in the lower portion of the window frame and a second connection point connected to the third connection point of the second link.

A reversible window structure as mentioned in the opening paragraph is a type of window in which the window pane can be "reversed". In this specification, the meaning of the term "reversed" should be understood in that when the window is "reversed" the surface of the window pane which faces outwards during normal use, faces inwards and the surface which faces inwards during normal use, faces outwards. This can be very useful, for example when cleaning windows. In the window cleaning example, the window can be pivoted by, for example, 170 degrees, thereby giving a person who is cleaning the window access to the "outside" surface of the window pane when the person is standing on the inner side of the window structure. In this way, it is not necessary to clean the windows from the outside of the window structure. This is especially useful in tall buildings, where window cleaning of the outer surface of the windows can be expensive and/or dangerous.

It is to be noted that the terms "outside" and "inside" when used in this specification, should be understood in the context of a normal window mounted in a wall of a house. The "outside" surface of the window is that

surface which faces outwardly and is exposed to the elements. The "inside" surface is that surface of the window which faces inwardly.

Description of related art

Some good examples of reversible window structures are given in WO 2006/042438, EP 0 141 000, US 4 658 474, GB 2 294 727 and GB 2 387 199. The closest prior art for the invention as claimed in the current claim set is the embodiment described in figures 3-6 of EP 0 141 000 as it has the most technical features in common with the current invention.

However, figures 3-6 of EP 0 141 000 disclose a single window and a single fitting for said window. The fitting which is disclosed is optimised for the window structure shown in the figures in order to achieve an almost horizontal motion of the centre of gravity of the window pane and window sash. In this way, the motion of the window is smooth since the force required to reverse the window is relatively constant since the centre of gravity does not move up or down very much. The almost straight line motion of the centre of gravity also reduces the amount of energy needed by the user of the window to reverse the window since the user doesn't need to "lift" the centre of gravity of the window pane very much.

However, according to EP 0 141 000, a unique fitting has to be manufactured for each size window. If, for example, the fitting as shown in EP 0 141 000 in figures 3-6 were used for a window which was 10% larger, the motion path of the centre of gravity of the window pane would no longer be optimized. In fact, at the point where the window pane is roughly horizontal, the centre of gravity would drop quite significantly. This can be seen in for example figure 6 of EP 0 141 000 where the motion path shows a considerable downward trend towards the end of its travel. If the window were made larger, then the downward motion would be even greater if the same fitting were used. Since

a typical window producer has windows of many different sizes, it is very expensive and complicated to make a separate fitting for each window size.

Summary of the invention

One aspect of the current invention is therefore to provide a fitting for a reversible window structure which can be used for a larger number of different sized window structures while maintaining an essentially horizontal motion path for the centre of gravity of the window pane.

This aspect is solved in part by providing a fitting where, when mounted on a reversible window structure, the vertical distance Di from the middle of the window frame to the first connection point of the first link and the vertical distance D ₂ from the middle of the window frame to the second connection point of the third link are essentially equal in the closed position of the window structure. In this way, a fitting is provided which ensures an essentially horizontal linear motion for a larger number of window size variants. Please note that "essentially equal" should not be interpreted as exactly equal. Essentially equal should be understood as being similar in length which has the effect that the fitting is essentially centred on the window frame. By making the fitting such that it is essentially centred on the middle of the window frame, the forces experienced by the fitting are also reduced.

It should be mentioned that the term "vertical distance" should be interpreted as the vertical distance between the two points, not the actual distance between the two points. Furthermore, the orientation "vertical" should be understood as that direction which is vertical in the figures.

In a preferred embodiment, the ratio between the vertical distance D-i and the vertical distance D2 can be between 0.8 and 1.2, preferably between 0.9 and

1.1 and most preferably between 0.95 and 1.05. All of these ratio's should be considered as comprised with the term "essentially equal" for the sake of this specification.

Since the first link is arranged as a link in tension, it can be made quite thin. This allows the window sash and the window frame to be mounted very close together. In many prior art fittings, it is necessary to have a large cut-out on the frame or sash in order to accommodate the fitting. In a preferred embodiment of a fitting the thickness of the first link can be between 0.1 mm and 2mm.

The invention also relates to a window structure comprising a window frame, a window sash, a window pane arranged in said window sash and at least one fitting according to the invention. In a typical setup, the window structure can comprise two fittings wherein the two fittings are arranged one on each side of the window sash. Typically the window structure will be arranged such that it pivots about its top edge and swings outwards when opened.

In a preferred embodiment, the window structure or the fitting can further comprise a track arranged along the sides of the window frame and where the top portion of the window sash is slideably connected to said track, such that the top portion of the window sash is slideable along the sides of the window frame in a vertical direction. It should be noted that the track could either be integrated into the frame, it could be integrated as a part of the fitting, or it could be a separate discrete unit which is mounted to the frame independently of the fitting.

In one embodiment, the first end of the second link can be attached to the window sash at a connection point which can be located essentially at the middle of the window sash. In one particular embodiment, the first end of the second link can be attached to the window sash at a connection point which

can be located essentially in line with the centre of gravity of the window sash. In this case, the motion of the centre of gravity follows the connection point between the sash and the fitting. Since the window pivots about the connection point, when the centre of gravity is aligned with the connection point, then the pivot motion of the window does not result in inertia moments about the connection point. This further smoothes the motion of the window pane when it is being opened and closed.

In another embodiment, the first end of the second link can be attached to a connection point of the window sash which is located at a point which is closer to the top of the window sash than to the bottom of the window sash. This is useful when using the fitting together with sash elements having flanges which hide a part of the fitting from the outside.

Furthermore, the length of the links of the fitting and the connection points can be arranged such that when the window structure is in the reversed position, then the top of the sash is arranged above the connection point between the second link and the third link. Again, this is useful when using sash elements having flanges which hide a part of the fitting from the outside.

It should be emphasized that the term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Brief description of the drawings

In the following, the invention will be described in greater detail with reference to embodiments shown by the enclosed figures. It should be emphasized that the embodiments shown are used for example purposes only and should not be used to limit the scope of the invention.

Figure 1 shows a perspective view of a first embodiment of a reversible window structure comprising a fitting according to the invention.

Figure 2 shows a partial perspective exploded view of the right side of the window structure shown in figure 1 when looking at the window from the outside.

Figure 3 shows a partial perspective exploded view of the left side of the window structure shown in figure 1 when looking at the window from the outside.

Figures 4a-4e show perspective views of the window structure of figure 1 in different positions, starting with figure 4a where the window structure is in a closed position and ending with figure 4e where the window structure is in a reversed position.

Figure 5 shows a schematic side view of the window structure of figure 1 in a slightly open position.

Figure 6 shows a sequence of schematic side views of the window structure of figure 1 in a number of different positions.

Figure 7 shows the path of the centre of gravity of the window pane when moving the window pane of the window structure of figure 1 from the closed position to the reversed position.

Figure 8 shows a schematic side view of a second embodiment of a window structure comprising a fitting according to the invention in its reversed position.

Figure 9 shows schematic side views of the embodiment shown in figure 5 in a number of different positions.

Figure 10 shows the path of the pivot point of the window sash when moving the window pane of the window structure of figure 8 from the closed position to the reversed position.

It should be obvious to the person skilled in the art, that the window structure according to the invention can be installed in many different orientations which would make the terms of orientation used in this specification meaningless. Therefore, please note that all references to orientations in this specification, for example horizontal, vertical, upper, lower, top, bottom, etc shall be understood with reference to the orientations shown in the figures.

Detailed description of the embodiments

The reversible window structure 1 shown in figures 1-6 comprises a window frame 2, a window sash 3, a window pane 4 and two fittings 5 for a reversible window, one fitting mounted on the left side of the window structure and one fitting mounted on the right side of the window structure.

It should be understood for the purpose of this specification that the window frame is the element which is fastened to the opening in the wall and does not move during normal operation of the window structure. The window sash should be understood as that part of the window structure which surrounds the window pane and swings in and out together with the window pane. It should also be noted that in certain cases, the window sash is an integral part of the window pane. It should be obvious to the person skilled in the art that the window pane could be made from many different types of materials. In some cases it could be glass, in other cases it could be a plate of metal. Many other different materials could be imagined, for example, plastic,

aluminium, wood, etc... Furthermore, for the rest of this specification, when reference is made to the window sash, then the window pane is also included. For example, the phrase "the centre of gravity of the window sash", should be understood as the centre of gravity of the unit which comprises the window sash and the window pane.

It should also be understood for the purpose of this specification that the term "fitting" should be understood as a mechanical assembly which performs a certain function. The fitting can comprise a number of elements.

Each of the fittings 5 comprises three links 6,7,8. The first link 6 has a first connection point 9 which is pivotably connected to the window frame 2 in the upper portion of the frame and a second connection point 10 which is connected to a first connection point 11 of the second link 7. The second link 7 furthermore has a second connection point 12 which is connected to the window sash 3 and a third connection point 13 which is connected to the third link 8. Furthermore, the first connection point 11 of the second link is arranged between the second and third connection points 12,13 of the second link. The third link 8 has a first connection point 14 which is connected to the frame 2 in the lower portion of the frame and a second connection point 15 which is connected to the third connection point 13 of the second link 7.

It should be noted that the portions referred to above, middle, upper and lower portions, should not be interpreted narrowly. For example, the term

"middle portion" should be understood as comprising a portion of the link which is centred on the centre of the link and is at least 50% of the length of the link. Also, the upper portion should be interpreted as that portion of the frame which is located above the centre point of the frame and the lower portion should be interpreted as being that portion of the frame which is located below the centre point of the frame.

The frame 2 of the window structure is made up of four elements, two side elements 2a, 2b, an upper element 2c and a lower element 2d. The frame 2 furthermore comprises a track 16 arranged on the inner side of both side elements 2a, 2b of the frame. Slider elements 17 mounted to the window sash 3 in the vicinity of the top edge 18 of the window sash 3 are arranged to engage with the track 16 and to slide along the track. In this way, the top edge 18 of the window is constrained to move along the track 16 arranged in the frame 2. The top edge 18 of the window sash is therefore slideable up and down in a vertical direction.

Due to the dimensions and arrangement of the fitting and track, when the window sash 3 is pivoted outwards, the fitting 5 moves the centre of gravity 19 of the window sash outwards along a roughly horizontal line, while the top edge 18 of the window slides downwardly in the track.

Figures 4a-4e show the sequence when the window sash is moved from the closed position (figure 4a) to the reversed position (figure 4e). It is to be noted that while the window sash is being pivoted from the closed position (figure 4a) to the horizontal position (figure 4c) the centre of gravity is moving outwardly and when the window sash is being pivoted from the horizontal position (figure 4c) to the reversed position (figure 4e) the centre of gravity of the window sash is moving inwards.

The schematic side views of the window structure 1 shown in figures 5-6 are simplified views of the window structure shown in figure 1. The reference numerals of figures 5 and 6 are the same as the reference numerals of figure 1. The dotted line marked with the reference numeral 20 represents the middle of the window structure.

As can be seen from figure 5, when the window structure 1 is in its closed position , the vertical distance Di between the first connection point 9 of the first link and the centre 20 of the window structure 1 is essentially equal to the vertical distance D ₂ between the second connection point 15' of the third link and the centre 20 of the window structure 1. In figure 5, the ratio between D1 and D2 is approximately 1.04.

Furthermore, from figures 1 and 5 it can also be seen that the second connection point 12 of the second link 7 is attached approximately at the centre of gravity 19 of the window sash. This means that the pivot point 21 of the window sash is located approximately at its centre of gravity 19.

In addition, it can be seen that the third link 8 is quite a bit longer than known in the prior art. In fact the ratio between the length of the third link and the length of the second link is about 0.40. This ratio in the prior art is below 0.30. By increasing the length of the third link, the maximum size of window which can be managed by the fitting is increased. This is because the maximum size window which can be managed by the fitting is dependent on the summed length of the second and third links. Due to the constraints of the window frame, the second link cannot be increased over a certain length, but the third link can be increased significantly when compared to the prior art.

It can also be seen that in the closed position of the window structure, the fitting is quite long when compared to the height of the window structure. In fact, in the case where the fitting being used is mounted in the smallest possible window, the length of the fitting is almost as long as the height of the window structure. That is to say that the first connection point of the first link

6 is very close to the top of the frame and the second connection point 15 of the third link is very close to the bottom of the frame. By making the entire fitting longer, the links of the fitting can be made longer which also

contributes to making a more straight line trajectory. It could be said that in the examples shown, the length of the fitting is at least 80% of the height of the window structure. It should be noted, that the length of the fitting should be understood as the distance between the connection points of the links. The track should not be considered a part of the fitting when considering the length of the fitting since the track will always run the entire height of the window pane.

From the sequence shown in figure 6, and from the trajectory plot of the pivot point 21 shown in figure 7, it can be seen that the pivot point 21 moves along an almost horizontal line. Since the pivot point 21 is arranged approximately at the centre of gravity 19 of the window sash and window pane unit, the centre of gravity also moves along an essentially horizontal line. In this way, the centre of gravity does not move up or down very much which makes the motion of the window smoother. Furthermore, it should be noted that the inertia moment about the pivot point is quite small since the centre of gravity is arranged essentially at the pivot point.

Figure 7 shows the trajectory of the pivot point 21 of the window pane and window sash unit. It should be noted that the trajectory of the pivot point 21 is also the trajectory of the second connection point 12 of the second link 7 of the fitting 5. As the lengths of the three links 6,7,8 are fixed, the trajectory of the second connection point 12 of the second link 7 follows a predefined path. The extent of the travel along the predefined path is defined by the size of the window to which the fitting is mounted. If the fitting is mounted on a larger window, then the travel of the fitting will be larger than if the fitting is mounted on a smaller window. This effect is shown in figure 7. The trajectory marked with the reference "B" shows the trajectory for the second connection point 12 of the second link 7 for the window shown in figure 3. The point with the reference numeral 22 represents the position of the second connection

point 12 of the second link 7 when the window is closed. The point with the reference numeral 23 represents the point when the window is horizontal.

The trajectory for the second connection point 12 of the second link 7 for a window which is 10% smaller than the window structure shown in figure 3 is shown by the trajectory with the reference A and which is located between the points 22 and 24. The trajectory for the second connection point 12 of the second link 7 for a window structure which is 10% larger than the window structure shown in figure 3 is shown by the trajectory with the reference C and which is located between the points 22 and 25. Note that the fittings used in the three trajectories A, B, C is the same, only the window structure's size has been changed.

Returning to figure 1-3, a number of extra details can be observed with the fitting which further improve the function of the fitting. For example, the thickness of the three links 6,7,8 has been optimized at certain places such that the fitting when folded up can be made very thin. Furthermore, the geometry of the links has been optimized such that the links can abut each other without overlapping. This makes it possible to make the links thick and strong without simultaneously increasing the total thickness of the fitting.

In particular, from figure 3, note the recess 26 in the second link just below the first connection point 11. This recess 26 is placed in the link such that the point of connection between the third link 8 and the frame 2 can fit inside the recess in the closed position of the fitting.

Another detail is the bends 27, 28 in the third link which offset the main body of the third link from the line which connects the first and second connection points of the third link. This allows the main body of the third link to abut the main body of the second link instead of overlapping the third link.

Also note the thinner area 29 around the third connection point 13 of the second link 7 and the thinner area 30 around the second connection point 15 of the third link 8. In this way, even though the two links 7,8 do overlap, the total thickness is not very large.

Also note that the frame comprises two members a wooden frame member

31 which is connected to the wall opening and an aluminium frame member

32 which is fastened to the front of the wooden frame member 31. The aluminium frame member 32 comprises the track 16 as well as the connection fittings 33 which connect the links to the frame.

Figure 8 shows a schematic side view of a second embodiment 101 of a window structure and fitting 105 according to the invention in its reversed position. As with the first embodiment 1 , the second embodiment 101 comprises a window frame 102, a window sash 103 and two fittings 105. In the simplified schematic view of figure 8, only one fitting can be seen. However, the general arrangement and operation of the second window structure 101 is very similar to the first window structure 1.

As with the first embodiment 5 of the fitting, the second embodiment 105 of the fitting again comprises three links. The general arrangement of the connection points of the links of the second embodiment is similar to the arrangement of the connection points of the links of the first embodiment.

Again it should be noted that in the closed position of the window structure, the vertical distance D1 between the first connection point 109 of the first link 106 and the centre of the window is essentially equal to the vertical distance D2 between the second connection point 115' of the third link and the centre of the window 120.

However, it should also be noted that in contrast to the first embodiment of the window structure 1 , in the second embodiment of the window structure the pivot point 121 of the window sash and window pane unit is not connected exactly at the centre of gravity 119 of the window sash 103 and window pane. In this way, in the reversed position, the top edge 118 of the window sash is located above the connection point 113, 115 between the second 107 and third links 108. This is useful for window sash elements which have a flange protruding from the sash which prevents the window sash from passing the third link.

It should also be mentioned, that for this current embodiment, when the fitting 101 is mounted on a window which is larger than the one shown in the figures, then the fitting will not be centred anymore, but will be mounted slightly above the centre point. The first connection point 109 of the first link 106 will still be connected at the top portion of the window frame 102. In other words, in the closed position of the window, the distance between the first connection point 109 of the first link 106 and the pivot point 121 of the window frame will be constant no matter what the size of the window. This means that the ratio between D1 and D2 will be slightly less than 1 when the fitting is mounted on a window structure which is larger than the window structure it was designed for.

Figure 9 shows a sequence of moving the window from its closed position to its reversed position. As can be seen, the pivot point 121 moves along an essentially horizontal line. Figure 10 shows the trajectory path for the pivot point 121 of the window sash 103 and window pane unit. The trajectory between points 122 and 123 is the trajectory for the window shown in figure 8. The trajectory for the pivot point of a window structure which uses the same sized fitting as the one shown in figure 8 but which is slightly larger than the window structure shown in figure 8, will be the same.

It should be noted that in the above examples, the track has been an integrated part of the frame's side elements, however, it should be obvious to the person skilled in the art, that the track 17, 117 could be a separate element which is attached to the frame, via for example screws, clips, etc. Furthermore, the track could also be an integral part of the fitting and be mounted to the frame via the fitting.

It should also be noted that in the above examples, the first connection point 9,109 of the first link and the first connection point 14, 114 of the third link have been connected directly to the frame. However, it should be obvious to the person skilled in the art that the fitting could further comprise a fourth link which connects the first and third links and which is then mounted directly to the frame.

It is to be noted that the figures and the above description have shown the example embodiments in a simple and schematic manner. The mechanical details have not been shown in great detail since the person skilled in the art should be familiar with these details and they would just unnecessarily complicate this description.