Coupled window

Abstract

 A coupled window comprises an outer sash (2) adapted for being hinged upon a window frame (3), an inner sash (5) hinged upon the outer sash (2), a recess (16) in the inner sash (5) limited by a first face (17) extending crosswise to the inner sash (5) and a second face (18) extending crosswise to the first face (17), and a double-glazing (8) attached to at least the second face (18) of the recess (16) by gluing. The coupled window further comprises a clearance (19) between the periphery (20) of the double-glazing (8) and the first face (17) of the recess (16), a access opening (19') of the clearance (19) placed opposite to the first face (17) of the recess (16), and a cover list (24) with a cover (25) for covering at least an area of the outer side of the double-glazing (8) at the access opening (19') of the clearance (19) and an anchor (26) for anchoring the cover list (24) in the clearance (19). The coupled window of the invention has a simple, inexpensive and strong structure, which has a low U-coefficient, a high Net Energy Gain value and allows a relatively large quantity of incident light to pass.

Description

[0001] The present invention relates to a coupled window which comprises an outer sash adapted for being hinged upon a window frame, an inner sash hinged upon the outer sash, a recess in the inner sash limited by a first face extending crosswise to the inner sash and a second face extending crosswise to the first face, a double-glazing attached to at least the second face of the recess, a clearance between the periphery of the double-glazing and the first face of the recess, and an access opening to the clearance.

[0002] The invention also relates to a method for producing the coupled window.

[0003] The term "coupled window" is used herein for a window, which comprises an outer sash hinged on a window frame and an inner sash hinged on the outer sash.

[0004] The term "thickness" is used for a dimension extending crosswise the coupled window and the term "width" for a dimension extending crosswise the thickness.

[0005] Enormous quantities of fossil fuels like e.g. coal, oil and gas are yearly combusted for generating heat for heating buildings. Therefore, the buildings are insulated for both reducing the serious contamination of the environment caused by combusting such fuels and also in order to reducing the relatively high costs used to heat the buildings.

[0006] The energy consumption for the space heating of buildings was in 2007 about 40 % of Denmark's total energy consumption, of which approximately 25 % are assumed to be heat loss through windows. There is therefore a considerably energy saving potential in developing new and better low-energy windows both for use in renovation of the existing building mass and for use in new buildings.

[0007] A windows rate of heat loss, i.e. it's thermal conductivity is indicated in terms of the U-coefficient (U-value/U-factor). The lower the U-coefficient, the greater a window's resistance to heat flow and the better its insulating properties.

[0008] However, the U-value takes no account of the positive benefits of windows - i.e. they let in both light and heat. Furthermore, the actual area and geometry of a window has a great influence on the overall window energy performance. This is due to the fact that a smaller window has a relatively greater frame fraction than a bigger window if using the same frame dimension. A small window dimension can therefore be expected to have a higher overall U-value and a lower total solar energy transmittance since the relative glazing area has been reduced.

[0009] New standards will therefore be applied in the future, based on both the heat loss coefficient (U-value) and the solar energy transmittance (g_w), i.e. the Net Energy Gain: E_ref = I*g_w - D*U_w [kWh/m²].

[0010] Where I is the solar radiation calculated for a reference house and D is the degree hour number during the heating season in Denmark. U_w is the total thermal transmittance and g_w is the total solar energy transmittance of the window. It is seen that the net energy gain will be negative when energy is lost, and it is therefore desirable to have a relatively high Net Energy Gain value - E_ref.

[0011] Further information on the net energy gain equation is described in Nielsen T. R., Duer K and Svendsen S, (2000), Energy performance of glazings and windows. Solar Energy, Vol. 69 (Suppl.), Nos. 1-6, pp. 137-143.

[0012] A coupled window having a low U-coefficient, is known from the applicant's own Danish patent no. 176456 B1. This known coupled window comprises an outer sash for being hinged upon a window frame and an inner sash which is hinged upon the outer sash whereby each sash is mounted with a single glass pan.

[0013] The two sashes of said known coupled window can pivot in relation to each other about their common hinges between a mutually closed and open state.

[0014] A sealing strip, which is attached to one of the sashes, seals a gap between the two sashes when they are in their mutually closed state. Said sealing strip is permeable for air whereby an airflow is passing between the two glass pans of the window.

[0015] This air, which is something hot because the air is taken from the heated room, keeps advantageously dew away from the glass pans in the closed state of the coupled window.

[0016] Said DK Patent No. 176456 B1 is included in the present patent application by reference.

[0017] Other double-glazing windows having a low U-coefficient is known from the UK Patent Applications GB 2044832 and GB 2440245 describing windows with two glass pans spaced apart by means of a spacer.

[0018] However, the rising need for being environmental by reducing the amount of fossil fuels to be combusted for heating buildings and also for reducing the high prices of said fuels causes a great demand for windows having an even lower U-coefficient than the above-mentioned known windows.

[0019] By combining the coupled window known from DK Patent No. 176456 B1 with the double-glazing window known from e.g. the UK Patent Applications GB 2044832 or GB 2440245 is obtained a window with a substantially lower U-coefficient than said windows have separately.

[0020] Such improved coupled window already exists in form of an outer sash with a single glass pan and an inner sash with a double-clazing. The inner sash is conventionally rectangular or quadratic with four bars having each a base and also a rib extending from the base. The base and the rib of the bar together form a recess in the bar with a first face on the base and a second face on the rib. The two faces are forming a right angle with each other. In mounted state the double-glazing is placed in said recess with a clearance between the periphery of the double-glazing and the first face of the recess.

[0021] The double-glazing and the material of the inner sash have normally different coefficients of thermal expansion. This causes the double-glazing and the inner sash to expand differently when being influenced by heat. Such different expansion is however allowed to take place owing to the presence of said clearance.

[0022] A glass bead of e.g. wood, which is attached to the base of each bar of the inner sash, is securing the double-glazing to the inner sash. A first rubber strip is moreover placed between the glass bead and the double-glazing while a second rubber strip is placed between the double-glazing and the second face on the rib of the bar.

[0023] The thickness of the inner sash is the sum of the thickness of the glass bead, the thickness of the first rubber strip, the thickness of the double-glazing, the thickness of the second rubber strip and the thickness of the rib of the bar.

[0024] Therefore, the thickness of the inner sash is unfortunately rather large whereby the known double-glazing window is imparted a unpleasant appearance which is not acceptable with an otherwise esthetic architecture.

[0025] For soften that unpleasant appearance and meeting the demands of a thinner window, the double-glazing is made relatively thin. This will result in a correspondingly high U-coefficient of the double-glazing and accordingly an increased loss of heat through the window and higher cost for heating.

[0026] The structure of the inner sash for mounting the double-glazing need to be strong enough to prevent deformation of the sash when being influenced by e.g. heavy wind loads, otherwise the sash will not be able to fit tightly to the window frame.

[0027] It is further important that the sash is able to securely maintain its rectangular or quadratic form, thereby effectively preventing that the required clearance between the periphery of the double-glazing and the first face of the recess in the bars is dislocated. This could namely cause the bars to collide with the periphery of the double-glazing and, if occasion should arise, resulting in that the window is more or less destroyed.

[0028] Therefore, the bars of the inner sash needs to have a sufficiently large bending moment and a corresponding large width for being able to resists forces acting onto the inner sash in the sash's plane. Each of the bars of the inner sash therefore needs to be relatively width whereby the free area of the double-glazing is correspondingly reduced with the result that the incident light is diminished.

[0029] The structure of the above-mentioned known coupled window in form of an outer sash with a single glass pan and an inner sash with a double-clazing also is complicated and costly.

[0030] The above-mentioned disadvantages of the prior art windows is according to the invention remedied by, in a first aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph, which has a simple and inexpensive structure,

[0031] in a second aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph, which has a lower U-coefficient than hitherto known,

[0032] in a third aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph, which allows relatively large quantities of incident light to pass,

[0033] in a fourth aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph, which seen in section is more narrow than hitherto known,

[0034] in a fifth aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph, which has a strong structure,

[0035] in a sixth aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph, which has a nice appearance,

[0036] in a seventh aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph, which is equipped with means for protecting sensitive parts of the window against UV-rays, and

[0037] in an eight aspect of the invention providing a coupled window of the kind mentioned in the opening paragraph with an advantageous net energy gain to the house still maintaining a long lifetime and an architectural attractive form.

[0038] Other aspects of the invention will be apparent during the course of the following description.

[0039] The novel and unique wherein the above mentioned features are achieved consists in the fact, that the coupled window comprises a cover list with a cover for covering at least an area of the outer side of the double-glazing at the access opening of the clearance and an anchor for anchoring the cover list in the clearance.

[0040] By means of the above-mentioned structure is advantageously obtained a simple and inexpensive structure of a coupled window of that kind which is mounted with a double-glazing in the inner sash of the window.

[0041] The thickness of the inner sash of the coupled window of the invention is substantially smaller than the thickness of the inner sash of the previously mentioned known coupled window owing to the fact that the thickness of the inner sash of said known window needs to be at least the sum of the thickness of the glass bead for securing the double-glazing to the sash, the first rubber strip, the double-glazing, the second rubber strip and the rib of each bar of the known sash, while the thickness of the inner sash of the window according to the invention only needs to be the sum of the relative thin cover of the cover list plus the thickness of the double-glazing and optionally a rib.

[0042] The inner sash of the invention therefore is very narrow which is not only cost saving but is also imparting the coupled window a nice and esthetic appearance.

[0043] The thickness of the double-glazing of the invention can according to the invention also be thicker than the double-glazing of the known coupled window, whereby a lower U-coefficient and a higher E_ref-value can be obtained, and accordingly a better protection against heat loss through the window.

[0044] According to the invention the double-glazing can be attached to the inner sash by gluing whereby the double-glazing and the sash together form a very stiff and strong unit which allows the inner sash of the invention to have a substantially smaller width than the sash of the known coupled window which has only the inner sash, which is not supported by the double-glazing, to withstand forces acting in the plane of the sash.

[0045] The double-glazing of the invention can therefore also have a larger extension than the double-glazing of the known coupled windows, and accordingly a lower U-coefficient.

[0046] In an advantageous embodiment according to the invention the double-glazing in the inner sash has a substantially larger extension than the glass pan in the outer sash, thereby ensuring that more incident light is allowed to pass the coupled window according to the invention than is allowed to pass the known coupled window.

[0047] As mentioned above the double-glazing according to the invention can be attached to the inner sash by gluing. This operation can more precisely take place by applying glue to the second face and/or the first face of the recess in each bar and then place the double-glazing in said recess in contact with said glue whereby the doubled-glazing and the sash quickly and easily will be secured to each other and in a very inexpensive way too.

[0048] For better being able to determine the thickness of the layer of applied glue, the glue can instead be applied to the double-glazing according to the invention, which thereafter is placed in the recess of each bar where the glue on the double-glazing comes in contact with the second face and/or the first face of the recess in each bar.

[0049] A very secure and strong connection between the double glazing and the sash is according to the invention obtained by applying glue on both the double-glazing and the first an second face of the recess in each bar.

[0050] In the mutually closed state, the outer and inner sash of the coupled window according to the invention will form a gap. Said gap will, like the coupled window known from DK 176456 B1, be tightened by means of a sealing strip.

[0051] This sealing strip can in one embodiment have a closed cellular structure and in another embodiment an open cellular structure.

[0052] In the last-mentioned case the sealing strip is permeable for air whereby a current of air is passing the space between the outer glass pan and the inner glass pan of the double-clazing. This current of air is advantageously keeping dew away from the window in the mutually closed state of the two sashes.

[0053] In both embodiments the sealing strip according to the invention is attached to the outer side of the cover of the cover list.

[0054] The cover list with its cover and anchor can according to the invention be made of a material which can be extruded to a stiff and/or rigid cover list and the sealing strip can continuously be attached to the cover of the extruded cover list. This will ensure that the sealing strip easily, quickly and precisely can be attached to the cover list and in an extremely inexpensive way too.

[0055] According to the invention can the cover list with the attached permeable sealing strip be mitred into lengths fitting to each their side of the inner sash and the anchor of the cover list can be placed into the clearance between the periphery of the double-glazing and the first face of the recess in the inner sash of the couple window.

[0056] The anchor of the cover list can according to the invention moreover be barbered so that the anchor easily and quickly can be secured in the clearance when having being introduced through the access opening of the clearance.

[0057] In another embodiment according to the invention can the anchor with or without barbs be secured in the clearance by gluing.

[0058] In a preferred embodiment according to the invention the cover of the cover list can be curved, seen in cross-section, and the concave side of the cover list can face the area covered by the cover so that the longitudinal edges of the cover tightly abuts the outer side of the double-glazing and the inner sash even if said outer sides are not complete plane.

[0059] The cover list can according to the invention furthermore be made of a material, which is impervious to UV-rays for protecting possible sensitive parts of the window against irradiation of UV-rays.

[0060] According to the invention the cover list can furthermore easily, quickly and safely be connected with the inner sash by introducing the anchor of the cover list via the access opening into the clearance, so that the cover of the cover list at the access opening of the clearance is covering an area on the outer side of both the double-glazing and the inner sash.

[0061] The invention will be explained in greater details below where further advantageous properties and example embodiments are described with reference to the drawings in which,

Fig. 1 shows a horizontal cross section, seen from above, of a coupled window according to the invention in the closed state of the window,

Fig. 2 shows the same, but with the window in an opened state,

Fig. 3 shows in a lager scale a fragment of the window shown in fig. 1,

Fig. 4 shows in a still larger scale a cover list of the window shown in fig. 1, seen in section,

Fig. 5 shows fragmentarily a length of the cover list shown in fig. 4, and

Fig. 6 is a fragmentarily front view taken along the line VI - VI in fig. 1.

[0062] An advantageous embodiment of a coupled window 1 is seen in fig. 1 where the window is closed and in fig. 2 where the coupled window 1 is open.

[0063] The outer sash 2 of the coupled window is hinged on the window frame 3 by means of a hinge 4 while the inner sash 5 is hinged on the outer sash 2 by means of another hinge 6.

[0064] The outer sash is formed in the same way as the outer sash of the coupled window known from the DK 176456 B1 in which the outer sash is mounted with a single glass pan 7.

[0065] The inner sash 5 is mounted with a double-glazing 8 whereby the coupled window of the invention advantageously is imparted a very little U-coefficient so that loss of heat through the coupled window of the invention is considerably reduced in proportion to the loss of heat through a conventional coupled window of e.g. the kind known from the earlier mentioned DK patent 176456.

[0066] The double-glazing 8 of the coupled window of the invention consists, as best seen in fig. 3, of an inner glass pan 9 and an outer glass pan 10. The two glass pans 9,10 are kept apart by means of a spacer 11, which airtight is attached to the two glass pans 9,10 by means of a glue 12.

[0067] The inner sash 5 consists, as seen in fig. 6, of fours bars 13 which together form a rectangle. Each bar 13 consists of a base 14 and a rib 15, which as seen in fig. 3, together form a recess 16 with a first face 17 on the base 14 and a second face 18 on the rib 15. The two faces 17,18 are in this case forming a right angle with each other.

[0068] The double-glazing 8 is placed in the recess 16 with a clearance 19 in between the periphery 20 of the double-glazing 8 and the first face 17 of the recess 16. This clearance serves for allowing the double-glazing and the bars of the inner sash to expand differently when being influenced by heat so that the risk of getting the window more or less destroyed when being influenced by heat effectively is eliminated.

[0069] The double-glazing 8 is moreover attached to the second face 18 and partly also to the first face 17 of the recess 16 in the bar 13 of the inner sash 5 by means of a glue 21 whereby the double glazing and the inner sash together form an integral unit which becomes so stiff and strong that the width of the bar can be relatively small and the two-dimensional extension of the double-glazing correspondingly larger.

[0070] As seen in fig. 1 is the double-glazing in the inner sash thus substantially larger than the glass pan in the outer sash whereby more incident light advantageously is allowed to pass the coupled window of the invention.

[0071] When the inner and outer sashes 2 and 5 is closed in relation to each other is a gap 22 formed between the sashes like in the coupled window known from the patent DK 176456 B1 and said gab 22 is, as best seen in fig. 3, likewise tightened by a sealing strip 23.

[0072] Said sealing strip 23 has an open cellular structure, which allows an air current to pass the space between the inner and outer glass pan 9,10 of the double-clazing via the sealing strip 23 so that dew is kept away from the opposite sides of the two glass pans 9,10.

[0073] The sealing strip 23 is, as seen in fig. 3, 4 and 5, according to the invention attached to the outer side of a cover list 24, which consists of a cover 25 and an anchor 26.

[0074] The cover list 24 is mounted onto the inner sash by anchoring the anchor 26 of the cover list 24 in the clearance 19 formed between the periphery of the double-glazing 8 and the first face 17 of the recess 16 in the bar 13, so that the cover 25 of the cover list 24 at the access opening 19' of the clearance 19 is covering an area on the outer side of both the double-glazing 8 and the inner sash 5.

[0075] As seen in fig. 4 is the cover 25 of the cover list 24 slightly curved whereby the cover 25 is forced to abut the outer sides of the double-glazing 8 and the inner sash 5 with its longitudinally extending edges 27 for thereby securing that the cover 25 fits tightly to said outer sides of the double-glazing 8 and the inner sash 5.

[0076] As previously mentioned are the two glass pans 9,10 of the double-glazing 8 kept apart by means of a spacer 11, which airtight is attached to the two glass pans 9,10 by means of a glue 12 and the double-glazing 8 is itself attached to the recess 16 in the bar 13 of the inner sash 5 by means of a glue 21.

[0077] Since said glues 12 and 21 can be more or less destroyed when being irradiated by UV-rays is the cover list 24 according to the invention made of a material, which is impervious to UV-rays whereby the cover 25 of the cover list 24 protects the glues against such harmful irradiation.

[0078] The anchor 26 is in the embodiment shown in fig. 3 and 5 secured in he clearance 19 by means of barbs 28 which are adapted in such a way that they allow air in the clearance to get past the bars during introducing of the anchor in the clearance through the access opening 19'. The anchor may be further secured in the clearance by gluing.

[0079] In a preferred embodiment according to the invention is the cover list 24 extruded (not shown) while a self-adhesive sealing strip 23 continuously is attached upon the outer side of the cover 25 of the cover list 24.

[0080] In this way is effectively secured that the sealing strip 23 precisely is positioned on the cover list and in an extremely inexpensive way too.

[0081] The extruded cover list 24 with the attached sealing strip 23 is cut in gearing in length fitting to each their side of the inner sash, as seen in fig. 6.

[0082] The thickness of the inner sash 5 is the sum only of the thickness of the cover 25 of the cover list 24, the thickness of the double-glazing 8 and the thickness of the rib 15 of the bar 13 of the inner sash 5.

[0083] The thickness of the inner sash of the invention therefore is substantially smaller than the thickness of the inner sash of a conventional coupled window of the same kind and even if the thickness of the double-glazing of the invention is considerably larger than the thickness of said conventional coupled window.

[0084] By way of example can be mentioned that the thickness of the sash and the double-glazing of the coupled window according to the invention and of the sash and the double-glazing of a conventional coupled window of the kind described on page 4 of this application, has been measured to have the following values.

Dimensions

	Invention	Conventional
sash	30 mm	45 mm
glazing	18 mm	14 mm

[0085] The relative little thickness of the inner sash of the invention is imparting a nice and esthetic appearance to the coupled window according to the invention.

[0086] The relative large thickness of the double-glazing is moreover imparting a low U-coefficient to the coupled window of the invention so that loss of heat through the window is substantially reduced.

[0087] This is also reflected in the fact that the Net Energy Gain is significantly higher than for the conventional windows.

[0088] In the paper "Energy performance of windows based on net energy gain by Svend Svendsen, Jesper Kragh, and Jacob B. Laustsen from DTU, a comparison of calculated energy properties of five different windows can be found for a standard window of 1.23, x 1.48m. All five windows had in said paper an E_ref-value between -45 and -51 kWh/m². Compared to this can be mentioned that the E_ref-value of a standard window according to the present invention has a E_ref-value of -11, i.e. a significantly better Net Energy Gain.

[0089] The invention is above described and on the drawing shown with a single glass pan in the outer sash. Within the scope of the invention can the coupled window however instead have a double-glazing in the outer sash.

Claims

1. A coupled window comprising,

- an outer sash (2) adapted for being hinged upon a window frame (3),

- an inner sash (5) hinged upon the outer sash (2),

- a recess (16) in the inner sash (5) limited by a first face (17) which is extending crosswise to the inner sash (5) and a second face (18) extending crosswise to the first face (17),

- a double-glazing (8) attached to at least the second face (18) of the recess (16),

- a clearance (19) between the periphery (20) of the double-glazing (8) and the first face (17) of the recess (16), and

- an access opening (19') into the clearance, characterized in that the window further comprises,

- a cover list (24) with a cover (25) for covering at least an area of the outer side of the double-glazing (8) at the access opening (19') of the clearance (19) and,

- an anchor (26) for anchoring the cover list (24) in the clearance (19).

2. A coupled window according to claim 1, characterized in that the double-glazing (8) is attached to at least the second face (18) of the recess (16), by gluing.

3. A coupled window according to claim 1 or 2, characterized in that a sealing strip (23) is attached to the cover list (24) and is tightening a space between the inner and outer sashes (3;5) in their mutually closed position.

4. A coupled window according to claim 3, characterized in that the sealing strip (23) is air permeable.

5. A coupled window according to any of the claims 1 - 4, characterized in that the cover (25) of the cover list (24) is covering both an area of the outer side of the double-glazing (8) and an area of the outer side of the inner sash (5) at the access opening (19') of the clearance (19).

6. A coupled window according to any of the claims 1 - 5, characterized in that the cover (25) of the cover list (24) is curved, seen in cross-section, and that the concave side of the cover (25) is facing the area covered by the cover (25) of the cover list (24).

7. A coupled window according to any of the claims 1 - 6 characterized in that the cover list (24) is made of a material, which is impervious to UV-rays.

8. A coupled window according to any of the claims 1 - 7, characterized in that the anchor (26) of the cover list (24) is barbed.

9. A coupled window according to any of the claims 1 - 8, characterized in that the anchor (26) of the cover list (24) is adapted to allow air in the clearance (19) to get past the barbs (28) of the anchor (19) during introducing of the anchor (19) in the clearance via the access opening (19') of the clearance.

10. A method for producing a coupled window according to any of the claim 1 - 9, characterized in extruding the cover list (24) and continuously attaching the air permeable sealing strip (23) to the cover (25) of the cover list (24) during extrusion of the cover list.

11. A method according to claim 10, characterized in mitring the cover list (24) and the attached permeable sealing strip (23) into length fitting each their side of the inner sash (5).

12. A method according to claim 10 or 11, characterized in applying glue (21) to at least the second face (18) of the recess (16) in each bar (13) and placing the double-glazing (8) in said recess (16) in contact with said glue (21).

13. A method according to claim 10 or 11, characterized in applying glue (21) to the double-glazing (8) and placing the double glazing (8) in the recess (16) of each bar (13) with the glue (21) in contact with at least the second face (18) of the recess (16).

14. A method according to claim 10 or 11, characterized in applying glue (21) to both the at least second face (18) of the recess (16) in each bar (13) and to the double-glazing (8), and placing the double glazing (8) in the recess (16) of each bar (13) in such a way that the glue (21) on the at least second face (18) of the recess (16) and the glue (21) on the double glazing (8) becomes in contact with each other.

15. A method according to any of the claims 10 - 14, characterized in placing the anchor (26) of each of the mitred length of the extruded cover list (24) with the attached permeable sealing strip (23) into the clearance (19) in such a way that the cover (25) is covering an area of at least the outer side of the double-glazing (8) at the access opening (19') of the clearance (19).

Drawing