A window, a window system comprising a plurality of sizes, and a method of providing a window with a displaced hinge axis. The invention relates to a window comprising a number of components including a frame and a sash, said window having dimensions corresponding to one predetermined size in a range of sizes, said sash being connected with the frame by means of a hinge de- vice defining a hinge axis of the window, the frame and the sash each including a first pair of mutually opposite members, and a second pair of mutually opposite members, said hinge device connecting a respective frame and sash member of the second pair of frame and sash members, a centre line being defined substantially midway between the one and the other of the members of said first pair. Windows of the pivoting or centre-hung type have found widespread acceptance, especially as roof windows, inter alia because this kind of window facilitates easy window cleaning, as the sash comprising the pane can be turned essentially 180° to allow cleaning of the outside surface of the pane from inside the building. A further advantage of this type of window it that it can be fully opened to a position where the sash is turned approximately 90° in which position air inlet is essentially unrestricted. Eventually, pivoting window provides for an easy operation, partly due to the position of the operating means at the top member of the sash, partly because the weight of the sash is substantially balanced with the hinge axis situated close to the centre line of the window.
On the other hand, the opening area restricted by the frame bottom and side members and the intersection with the sash including the window pane at the hinge axis is, of course, substantially smaller than in a top-hung window of the same size. This entails, i.a., that pivoting windows are not or only rarely used when a large opening area as defined in the above is desired. Such desired applications may e.g. include the use of the window as an emergency escape or emergency access. In the prior art, there are numerous examples of windows in which it has been sought to combine the advantages of top-hung and pivoting windows. EP publications Nos . 679774, 679775, 679776 and 972885 each discloses a window, in which a sash is carried in an auxiliary frame or a set of arms. The auxiliary frame or each arm is at one end hingedly connected with the frame top member and at its other end with the sash. The sash is furthermore connected with the frame by means of cooperating sliding means. In this manner, the window may serve as a top-hung window, in which the arms move synchronically with the sash, which is thus rotated about the hinge connection at the frame top member, or as a tilting win- dow. The above-mentioned solutions comprise designs having a number of special or additional elements and are thus rather elaborate . Additionally, it is known, i.a. from EP patent No. 733 146 to provide a top-hung window with an intermediate frame, which renders turning of the glass- carrying sash possible, in order to allow cleaning of the outside surface of the pane. Although this solu-
tion makes it possible to combine the advantages of top-hung and pivot windows, the pivoting function is only intended to be used when cleaning the outside of the window, which in most cases will be much more seldom than the use for e.g. ventilating purposes. Furthermore, the intermediate frame renders the manufacture and assembly of the window more expensive. With this background it is the object of the present invention to provide a window, in which the advantages of a top-hung and a pivoting window are combined, but which at the same time is of a simple structure and which may furthermore be produced in a cost-effective manner. This object is attained by the provision of a window of the kind mentioned in the introduction, which is furthermore characterized in that the hinge device comprises a set of pivot hinges mounted in such a position that the hinge axis is situated between said centre line and said one member of said first pair, and that at least one component of the window of said predetermined size is replaced by a corresponding component of a window of another size in said range of sizes, thereby determining said position. By simply moving the hinge axis towards one member of the frame and sash, respectively, preferably towards the top of the window, a substantially larger opening is obtained, while at the same time, the window is easy to operate. By the provision of a larger opening, it becomes possible to utilize the window as an emergency escape. In a traditional pivoting window, this would have required either choosing a larger model of the window, which is not always
feasible or desirable, or a top-hung window with the disadvantages listed in the above. The fact that the window is composed by components of a window of a particular size and of another size within a range of sizes, entails that it is not required to intervene in the manufacturing process more than strictly necessary, as windows will usually be available in a range of sizes at any rate. In turn, this provides for a particularly simple and inexpensive window, as the number of different components to be kept in store is not or only slightly increased. This is particularly pronounced in relation to windows in which the components are to some extent custom-made in order to attain the particular position of the hinge axis. In an advantageous embodiment, the exchangeable component comprises the cladding of the window. In pivotal windows, the cladding of a side is traditionally formed from two pieces, of which one extends from the bottom of the window to the hinge axis, and the other from the hinge axis to the top of the window. Thus, each individual size of a traditional pivot window has its own lengths of cladding pieces. By replacing the lower piece by the piece of a lar- ger, i.e. taller window, and the upper piece by that of a smaller, i.e. shorter window, it is thus possible to obtain a displaced hinge axis by positioning the hinge device accordingly on the side members of the sash and the frame. Additionally or alternatively, the component may comprise positioning means for the hinge device. Such hinge device positioning means may comprise a recess formed in the side of the members of
the second pair of frame and sash members. The recess may e.g. be formed by a milling cutter tool, which forms the recess in the sash and frame members at a predetermined position. In order to apply the meas- urements of the window of another size to the particular window, the tool may be set to form the recess correspondingly, or the side member of the window of a larger size, with an already formed recess, is cut into the appropriate length. Alternatively, the hinge device positioning means may comprise at least one striking list connected with the side of the members of the second pair of frame and sash members. Eventually, it is of course possible to let the component comprise a positioning means only, such positioning means comprising means for positioning a number of drillings. In another aspect of the invention, a window system comprising a plurality of windows is provided. Each window of the window system has dimensions corresponding to a predetermined size, and the plurality comprises a range of sizes, each window comprising a number of components. The window system is characterized in that said window system further comprises at least one window of a predetermined size including partly components of the window of said predetermined size, partly one or more components of a window of another size in said range of sizes. In order to provide windows having a horizontal hinge axis, which is displaced with respect to the centre line, the dimension determining the size is the height of the window. The range of available sizes and the difference
between the individual sizes may of course vary to a wide extent, but preferably, the height of one window of one size deviates from the height of a window of an adjoining size by a predetermined increment. In a preferred further development of this embodiment, the height varies between approximately 0.8 m and 1.8 m, and the increment is approximately 0.2 m. These values provide for a suitable range and differentiation between the sizes. Still another aspect presents a method for providing a window with a hinge axis situated between a centre line and one member of a first pair of members of the window, characterized in the following steps: determine a dimension of the required opening, deter- mine the corresponding overall dimension, select a predetermined window size with a dimension corresponding to the corresponding overall dimension, replace at least one component of the selected window by a corresponding component of a window of another size in a range of sizes to achieve the required opening, and assemble the window from said components . In a preferred further development of this method, the first pair of members constitutes the top and bottom members of the frame and sash, and said dimensions are heights measured in the direction from the bottom member to the top member of the frame and sash, respectively. The invention will be described in further de- tail with reference to the schematic drawings, in which Fig. 1 shows a perspective view of a window according to the invention,
Fig. 2 shows a diagrammatic side view of the window of Fig. 1, Fig. 3 shows an exploded perspective view of the sash of a window in an embodiment of the inven- tion, and Fig. 4 shows a perspective view of the frame of a window in an embodiment of the invention. The window shown in Fig. 1 comprises a number of components, including a frame 1 with a first and a second pair of mutually opposite frame members. The first pair consists of one member in the form of a top member 3 and another member in the form of a bottom member 4. The two members of the second pair constitute side members 5 and 6, each extending between the top and bottom members 3 and 4 to form a substantially rectangular frame 1 intended to be built-in in e.g. an inclined roof (not shown) . A sash generally designated 2 is constructed in a similar manner with a top member 7, a bottom member 8 and side members 9, 10. In the sash 2 a window pane 11 of any type, e.g. an insulating unit, is enchased. The window is protected against the weather by an arrangement of cladding pieces and flashing elements (not shown) , of which only the cladding pieces 110a and 110b protect- ing the sash side member 10 will be referred to. The sash 2 is connected with the frame 1 by means of a hinge device, which in the embodiment shown comprises a set of hinges, of which one hinge 12 is shown in Fig. 1, at corresponding side members 5 and 9, and 6 and 10, respectively, of the frame 1 and sash 2. The set of hinges may be designed e.g. as disclosed in Applicant's European patent No. 1038083, the contents of which are incorporated herein by ref-
erence. Each hinge 12 thus includes a first plate for connection with the frame side member 5, 6 and a second plate for connection with the sash side 9, 10 member of the second pair, and the hinge 12 includes cooperating pins and guides as disclosed in further detail in the above-mentioned European patent. The use of a pivot hinge makes it possible to establish an overlap between the sash and the frame in the closed position of the window, without the use of elaborate devices such as linkage mechanisms. This is a particularly important feature in windows installed in a roof. The set of hinges 12 define a hinge axis 13 and are positioned between the top members 3 and 7 of the frame 1 and the sash 2, respectively, and a centre line 14 of the window. The centre line 14 is situated substantially midway between the top and bottom members 3 and 4 of the frame 1, corresponding in substance to the position midway between the top and bottom members 7 and 8 of the sash 2. The determination of the position of the hinge axis 13 will be described in further detail in the following, but the position will normally be such that a suitable balance between ease of operation of the window and a suitable opening defined by the bottom member 4, the side members 5 and 6, and the intersection of the sash 2 including the pane 11 at the hinge axis 13 is obtained. In order to bring the window from the closed position to an open position, e.g. a ventilating position, operating means are provided. Such operating means are known per se and may comprise a ventilating flap on the sash top member, or a handle at the sash
bottom member, cooperating with locking means on the frame. Furthermore, an auxiliary opening device may be provided, including e.g. one or more pressure medium operated cylinders or a torsion spring connected with the hinge device. The window described in the above forms part of a window system comprising a plurality of windows of different sizes. Each window within one size has dimensions corresponding to that particular size and the plurality comprises a range of sizes. As hinted at in the above, each window comprises a number of components, and as will be described, each window comprises partly components of the window of the predetermined size, partly one or more components of a window of another size in the range of sizes. Furthermore, there are components that are common to all sizes of the window system. If a window having a horizontal hinge axis is to be utilized as an emergency escape and access, it is the opening defined by the bottom member 4, the side members 5 and 6, and the sash 2 including the pane 11 at the hinge axis 13 that is crucial. In comparison with a top-hung or a traditional, centre-hung pivot window, the window according to the invention has the same width of the opening, whereas the height of the opening along the frame side members 5 and 6 is to be designed as having a required lowest value. Consequently, the following part of the description will relate to the height dimensions only, whereas it is to be understood that the window system may comprise windows having different widths, and all combinations of width/height are of course conceivable. In the window system, the height of a window of
one size preferably deviates from the height of a window of an adjoining size by a predetermined step or increment. In other words, if the height of a window of a particular size is denoted hx, then the heights of the adjacent window sizes are hx_ι and hx+ι, respectively. The height of an arbitrary window of a size n away from the window of the size hx is thus hx+n = hx + n*s, s being the increment. For instance, in the described embodiment the height varies between approximately 0.8 m and 1.8 m, and the increment is approximately 0.2 m. It is noted that the term 'height' is understood as a dimension measured between the top member and the bottom member of the sash or frame of the window. The sash will tradition- ally have somewhat smaller overall dimensions than the frame . Referring now in particular to Fig. 3, the exchangeable component comprises the cladding of the window. As described in the above the cladding of a side sash member 10 is formed from two pieces, of which the lower cladding piece 110a is fastened to the side sash member 10 and extends from the bottom sash member 8 substantially up to the hinge axis 13, and the upper cladding piece 110b from the hinge axis 13 to the top of the window. As the upper portion of the sash 2 turns inwards during opening, cf. Fig. 1, the upper cladding piece 110b must be fastened to the frame side member 6. By replacing the lower cladding piece of the selected window by the piece of a larger, i.e. taller window, and the upper piece by that of a smaller, i.e. shorter window, it is thus possible to obtain a displaced hinge axis by positioning the hinge device
accordingly on the side members of the sash and the frame. In the above-mentioned specific example, it is possible to move the hinge axis in the direction towards the top of the window by approximately 0.1 m (half the increment) or e.g. 0.3 m (by utilizing components from a window three sizes above the selected window) . The component determining the position of the hinge axis may also comprise positioning means for the hinge device on the sash and/or the frame. In this case, the sash cladding pieces are chosen from the window size match the changed distance between the bottom member and the hinge axis, and between the hinge axis and the top, respectively. Alternatively, they may be supplied as a standard length (e.g. corresponding to the largest window size) and then cut to the appropriate length. Referring again to Fig. 3, the hinge device positioning means comprises, in the embodiment shown, a moulding in the form of a striking list 109c, 110c connected with the outer side of the respective side sash member 9, 10. As is the case with the cladding pieces, each window size in the window system has its individual length of striking list. Each striking list 109c, 110c is provided with a rounded end 109d,110d, which defines the position of the respective hinge. A similar striking list may be positioned on the opposite side of the hinge, above the hinge axis, such that the striking lists on each side form a recess. With respect to the frame 1, this component may be provided with hinge device positioning means as well. In the embodiment shown, see Fig. 4, the posi-
tioning means comprise a recess 106a formed in the inner side of the respective side frame member 5,6. The recess 106a may e.g. be formed by a milling cutter tool, which forms the recess in a predetermined position. In order to apply the measurements of the window of another size to the particular window, the tool may be set to form the recess correspondingly, or the side frame member of the window of a larger size, with an already formed recess, may be cut into the appropriate length. Although not shown, it is of course possible to let the component comprise a positioning means only, such positioning means comprising means for positioning a number of drillings. Referring now to Fig. 2, the method for providing a window with a hinge axis 13 situated between the centre line 14 and the top of the window is, in practice, carried out as follows: The dimension of the required opening is deter- mined. As explained in the above, only the height dimension will be contemplated. The required opening height may thus e.g. constitute the minimum requirements for allowing the window as an emergency opening. The preferable corresponding overall dimension, e.g. the maximum possible height, is then determined. This is carried out with due respect to i.a. installation conditions. A predetermined window size is then selected from the range of sizes in the window system. Consequently, the window is chosen with a height hx corresponding to the preferable overall height. At least one component of the selected window
size is then replaced by a corresponding component of a window of another size in the range of sizes, and the available opening dimensions 1 within this window size is evaluated by means of the formula: 1 = hx+n /2. For instance, for a window size having hx = 1.0 m in the above-mentioned example of a window system, in which s = 0.2 m, with n = 2, then 1 = 0.7 m. In other words, it is possible to displace the hinge axis 13 a distance d = 0.2 m from the centre axis 14. If this opening height is acceptable, then the predetermined window size hx and the opening height 1 are selected as indicated in the above. The components corresponding to the size hx and hx+2 are then selected and the window is assembled from these components. The ratio r between the position of the hinge axis and the height of the window is thus r = 1 - 1/ hx. The possible values of this ratio r in the embodiment shown in the drawings thus range from virtually 0 (corresponding to a top-hung window) to 0.5 (corresponding to a pivot window having a central hinge axis) . Preferably, the ratio r lies in the interval 0.1 to 0.4, more preferably 0.17 to 0.33, and most preferably 0.25. The invention should not be regarded as being limited to the embodiments described in the above, but various modifications and combinations may be carried out. For instance, the window may be built-in in a facade, and the sash may be hingedly connected with the frame with the hinge axis extending in par- allel with the side members of the frame and the sash.