WO2020048848A1

WO2020048848A1 - Window and assembly comprising a frameless sash flush with a fixed frame

Info

Publication number: WO2020048848A1
Application number: PCT/EP2019/072985
Authority: WO
Inventors: Pierre Schneider; Amélia DESMEDT
Original assignee: Agc Glass Europe
Priority date: 2018-09-07
Filing date: 2019-08-28
Publication date: 2020-03-12
Also published as: EP3847335A1; TW202026514A

Abstract

The present invention concerns a window comprising a frameless sash (10) defined by an inner surface and an outer surface, the frameless sash having a thickness, W10, and a fixed frame (20) having an inner face and an outer face comprising, °a fixed frame profile (21) defining a frame opening, having an outer side bounded by an outer frame perimeter mating the outer glazing perimeter and an inner side bounded by an inner frame perimeter mating the inner glazing perimeter, ° receiving elements for coupling the frameless sash to the fixed frame in a closed position, ° a cover plate (22) coupled to and covering at least 10% of a surface area of the outer side over substantially a whole of an outer perimeter of the fixed frame profile, wherein the fixed frame (20) has a thickness, W20, which is equal to the sum of thicknesses, W21 and W22, of the fixed frame profile and of the cover plate (i.e., W20 = W21 + W22), characterized in that, ° the thickness, W20, of the fixed frame is equal to the thickness, W10, of the frameless sash, within a tolerance of ± 5% (i.e., W20 = W10 (1 ± 5%)), in that ° when the frameless sash is in the closed position, the inner and outer faces of the fixed frame are flush with the inner and outer surfaces of the inner glazing (10n), respectively, and in that ° the thickness ratio, W21 / W20, of the fixed frame profile (21) to the fixed frame (20) is at least 80%.

Description

WINDOW AND ASSEMBLY COMPRISING A FRAMELESS SASH FLUSH WITH A FIXED FRAME

TECHNICAL FIELD

[0001] The present invention is in the field of windows in the broad sense of the term, incl uding openable windows such as casement windows, tilting windows, sliding 5 windows and glass doors in general as well as non-openable windows. The windows com prise a sash coupled to a fixed frame mounted i n an opening or tunnel of a wall or similar. The present invention concerns more particularly high-performance windows comprising a frameless sash defined by an inner surface bounded by an inner glazing perimeter and by an outer surface bounded by an outer g lazing perimeter, wherein the 0 in ner surface and the outer su rface are made of an inner glazi ng and an outer glazing, the inner and outer glazings comprising no outer frame profile. The present invention proposes a novel concept of windows facilitating maintenance and cleaning of the windows, increasing the openi ng ratio, and offering new design opportun ities with new aesthetic aspects available to the designers. 5 BACKGROUND OF THE INVENTION

[0002] Windows are typically composed by a sash coupled to a fixed frame mounted in an opening or tunnel of a wall or similar. The sash comprises one, two, or more glazings coupled to frame profiles extendi ng over a part or a whole of a glazi ng peri meter. The frame profiles are typically made of wood, metal, polymer, or composite material. A0 glazing can consist of a sing le glass pane or of multiple glass panes. The frame profiles can be inner frame profiles or outer frame profiles. The term “inner frame profile” is herein understood to mean the frame profiles which are encased between at least two glazings so as not to extend beyond the glazings perimeters. The term “outer frame profile” by contrast, is understood to mean the frame profiles which are fixed to the inner5 surface and /or the outer surface of the glazing facing an inner and /or an outer environment of the window, respectively. The outer frame profiles are always visible at least from one of the inner or outer environment of the window. Typically, sashes comprising one or more glazings with no outer frame profile are designated as“frameless sashes”. Frameless sashes have been available on the market for several years and are generally characterized by larger transparent see-through areas than corresponding sashes of same dimensions provided with an outer frame. Frameless sashes comprise an inner glazing defining the whole of the inner surface of the sash, and an outer glazing defining the whole of the outer surface of the sash, the inner and outer surfaces being 5 bounded by inner and outer glazing perimeters. The inner and outer glazings are maintained separated and parallel to one another by at least one gap defined within a peripheral spacer and comprise no outer frame profile. Frameless sashes actually comprise an inner frame profile, which is encased between the inner and outer glazings and within the peripheral spacer(s) and the inner and outer glazing perimeters. It is 0 formed by profiles which ends are coupled to one another to form the inner frame profile.

The inner frame profile is designed to accommodate the hardware required for locking the frameless sash in a closed or a semi-open position (e.g., tilting). For casement windows, the hinges allowing opening and closing of a sash can also be enclosed within the inner frame profile so as not to be visible from either side of the window. 5 [0003] EP3228795 describes a frameless sash window, comprising an inner frame profile made of wood encased between an outer and inner glazing. EP2436865 describes a frameless sash window comprising an inner frame profile made of polymer or aluminium encased between an outer and inner glazing.

[0004] The frameless sash is coupled to a fixed frame, itself being sealingly coupled to0 a perimeter of a tunnel defined by an opening in a wall, with an inner face of the fixed frame facing an inner environment and an outer face of the fixed frame facing an outer environment, such that the inner environment is separated from the outer environment by the wall and the window when the frameless sash is in the closed position.

[0005] The fixed frame can typically be formed by fixed frame profiles made of5 aluminium, wood, polymer, or a composite material. Aluminium has the advantage of being extremely weathering resistant, unlike wood and polymers in general, which are sensitive to UV. Because of the high thermal conductivity of aluminium and although aluminium fixed frames are provided with a thermal barrier generally consisting of a polymer bloc, typically a thermoplastic bloc such as a polyamide bloc sandwiched0 between two aluminium elements to reduce the thermal conductivity across a thickness of the fixed frame, aluminium fixed frames yield the worst heat transfer coefficients, Uf, of all materials currently used as fixed frames. It follows that aluminium fixed frames are not an optimal choice for highly energy-performant windows.

[0006] When using weathering-sensitive materials, such as wood and some polymers, it is current to apply a cover plate over at least a portion of the outer side of the fixed frame, extending over the whole perimeter thereof. This cover plate must be made of a weathering-resistant material, such as metal (e.g., aluminium, (stainless) steel), UV-resistant polymers or composites, or even ceramics. Such cover plates are visible in the Figures of EP3228795, with a wooden fixed frame profile, and of EP2436865 with a polymeric fixed frame profile. Similarly, EP2436865 describes a four glazing frameless sash coupled to a fixed frame profile made of wood or of a polymeric profile. The outer side of the fixed frame profile is protected by a cover plate.

[0007] The cover plate used to protect the outer side of fixed frame profiles made of a weather-sensitive material, however, forms areas where dirt can accumulate which are difficult to clean properly. Furthermore, the cover plate generally overlaps with the frameless sash. This results in a frame opening of smaller area, wherein the frame opening is the opening defined by the fixed frame (i.e., without the frameless sash) fixed to a tunnel in a wall. In the literature, the frame opening is also sometimes called window opening, the two terms being considered herein as synonyms. The frame opening area can be quantified relative to the tunnel area by an opening ratio, A0 = Af / At, of the area of the frame opening to the area of the tunnel in the wall.

[0008] The present invention proposes a highly energy-performant window comprising a frameless sash coupled to a fixed frame comprising fixed frame profiles made of a weathering-sensitive material, which is of easy maintenance and cleaning, and which enhances the opening ratio. Furthermore, the present invention opens the door to new aesthetic concepts in the building industry. These and other advantages are described in more details in the following sections.

SUMMARY OF THE INVENTION

[0009] The present invention is defined in the appended independent claims. Preferred embodiments are defined in the dependent claims. In particular, the present invention concerns a window comprising,

(a) A frameless sash comprising

• an inner glazing defining an inner surface bounded by an inner glazing

5 perimeter, parallel to an outer surface of an outer glazing, bounded by an outer glazing perimeter, the inner and outer glazings being separated from one another by at least one gap defined within a peripheral spacer and comprising no outer frame profile,

• an inner frame profile lodged within a volume defined between the inner 0 and outer glazings and between the peripheral spacer and the inner and outer perimeters,

wherein the frameless sash has a thickness, W1 0, measured normal to the outer surface and extending between the outer surface of the outer glazing and the inner surface of the inner glazing, 5 (b) A fixed frame defining a frame opening having an outer face bounded by an outer frame perimeter mating the outer glazing perimeter and an inner face bounded by an inner frame perimeter mating the inner glazing perimeter, said fixed frame comprising,

• a fixed frame profile having an inner side and an outer side, and having a0 thickness, W21 , measured normal to the outer surface when the frameless sash is in a closed position,

• receiving elements for coupling the frameless sash to the fixed frame in the closed position, closing the frame opening, wherein the inner and outer glazing perimeters of the frameless sash are coupled to the inner5 and outer frame perimeters of the fixed frame, respectively,

• a cover plate coupled to and covering at least 1 0% of a surface area of the outer side of the fixed frame profile over substantially a whole of the outer frame perimeter, said cover plate having a thickness, W22, measured normal to the outer surface (1 0a) when the frameless sash is in the closed0 position, wherein the fixed frame has a thickness, W20, measured normal to the outer surface (1 Oa) when the frameless sash is in the closed position, which is equal to the sum of the thicknesses, W21 and W22, of the fixed frame profile and of the cover plate (i.e., W20 = W21 + W22),

5 (c) Sealing elements mounted on the fixed frame and/or on the frameless sash to form a seal between the fixed frame and the frameless sash when the latter is in the closed position, for sealingly closing the frame opening when the frameless sash is in the closed position,

wherein, 0 · the thickness, W20, of the fixed frame is equal to the thickness, W1 0, of the frameless sash, within a tolerance of ± 5%, preferably of ± 2%, in that

• when the frameless sash is in the closed position, the inner face of the fixed frame is flush with the inner surface of the inner glazing, and the outer face of the fixed frame is flush with the outer surface of the outer glazing, and in that 5 · the thickness ratio, W21 / W20, of the fixed frame profile to the fixed frame (20) is at least 80%, preferably at least 90%.

[0010] The receiving elements are suitable for coupling the frameless sash to the fixed frame in one of the following manners,

• the frameless sash is fixedly coupled to the fixed frame in the closed position, or0 · the frameless sash is movingly coupled to the fixed frame such that the frameless sash can reversibly move with respect to the fixed frame from the closed position to an open position wherein the frameless sash leaves open at least a portion of the frame opening, either

o by rotation of the frameless sash about hinges fixed to the fixed frame5 and defining a rotating axis parallel to the outer surface when the frameless sash is in the closed position, or

o by translation of the frameless sash with respect to the fixed frame along a translation vector, wherein the translation vector comprises at least a first component normal to, and a second component parallel to the outer surface (1 0a) when the frameless sash is in the closed position.

[0011] The fixed frame profile can be made of wood, polymer, a fibre reinforced polymer composite or a combination thereof. It preferably has a frame heat transfer coefficient, 5 Uf, of not more than 1 .4 W / m² K. The thickness, W21 , of the fixed frame is preferably not more than 70 mm, more preferably not more than 65 mm and most preferably not more than 60mm.

[0012] In a preferred embodiment, the cover plate can be made of metal, a UV-resistant polymer or a UV-resistant fibre-reinforced polymer composite. The resistance to UV of0 the cover plate should be higher than the resistance to UV of both fixed frame profile and sealing elements. The cover plate thus forms a barrier against water and UV for the sealing elements and at least for part of the fixed frame profile. The thickness, W22, of the cover plate is preferably not more than 1 5 mm, more preferably not more than 1 0 mm and most preferably not more than 7 mm. 5 [0013] In one embodiment, the frameless sash comprises one intermediate glazing forming a three glazing unit formed by an outer-, intermediate-, and inner-glazings separated from one another by two gaps, each gap being defined within a peripheral spacer. In an alternative embodiment, the frameless sash comprises two intermediate glazings forming a four glazing unit formed by an outer-, first intermediate-, second0 intermediate-, and inner-glazings separated from one another by three gaps, each one defined within a peripheral spacer.

[0014] The frameless sash is preferably movingly coupled to the fixed frame. In many embodiments, the inner glazing perimeter is larger than the outer glazing perimeter, wherein in a projection onto the outer surface, the outer glazing perimeter is comprised5 within the inner glazing perimeter.

[0015] The inner glazing and the outer glazing comprise an inner peripheral region and an outer peripheral region extending inwardly from an edge of the inner and outer glazings, along the whole of the inner and outer glazing perimeters, respectively, to preferably at least the peripheral spacer contacting the corresponding glazing. In order to hide the hardware encased in the inner profile, it is preferred that the inner and outer peripheral regions have a visible light transmission, TL, at least 50% lower than the inner glazing and the outer glazing, outside of the respective inner and outer peripheral reqions. The inner and outer peripheral regions are preferably translucent or opaque.

5 [0016] At least one glazing can be provided with at least a heat ray reflection film or a low-emissivity film. Alternatively or additionally, at least one of the glazing can be an interactive glazing, preferably selected among an electrochromic, thermochromic, or photochromic device, a photovoltaic device, a multimedia connection, an antenna, communication means, a TV set, a light source including a LED, a loudspeaker, a sensor 0 including an irradiance-, temperature-, or acoustic- sensor, or a combination thereof.

The window can comprise a mechanically, pneumatically or electrically actuating device for reversibly moving the frameless sash with respect to the fixed frame from the closed position to the open position. A remote-control system, including a receiver integrated in the frameless sash and /or the fixed frame can be provided for actuating the moving 5 of the frameless sash or a functional element.

[0017] The glazings of the frameless sash preferably have a thermal transmittance coefficient, Ug, of not more than l .O W / m² K, more preferably of not more than 0.7 W / m² K.

[0018] The present invention also concerns an assembly comprising: 0 · a wall separating an inner environment from an outer environment and provided with a through opening in the form of a tunnel defined by a tunnel perimeter, and • at least a window as defined supra, wherein the fixed frame is sealingly coupled to the tunnel perimeter, with the inner face of the fixed frame facing the inner environment and the outer face facing the outer environment, such that the inner5 environment is separated from the outer environment by the window when the frameless sash is in the closed position.

[0019] The wall has a thickness, W30, measured normal to the outer surface when the frameless sash is in the closed position. The thickness, W30, is preferably greater than or equal to the thickness, W20, of the fixed frame, W30 > W20. The inner face of the fixed frame is preferably flush with the wall at the inner environment and /or the outer face of the fixed frame is preferably flush with the wall at the outer environment.

BRIEF DESCRIPTION OF THE FIGURES

[0020] For a fuller understanding of the nature of the present invention, reference is 5 made to the following detailed description taken in conjunction with the accompanying drawings in which:

Figure 1 : shows a transverse section of a window according to the present invention comprising a frameless sash made of three glazings separated by two peripheral spacers (a) in a closed position, and (b) in an open position. 0 Figure 2 : shows various types of windows according to the present invention, (a) sliding door / window, (b) casement window with two frameless sashes opening by rotation about vertical axes (= stulp windows) (c) casement window with one frameless sash opening by rotation about a vertical axis, and (d) tilting window opening by rotation about a horizontal axis. 5 DETAILED DESCRIPTION OF THE INVENTION

[0021] As illustrated in Figure 1 (a), the present invention concerns a window comprising a frameless sash (1 0) coupled to a fixed frame (20).

Frameless Sash

[0022] The frameless sash comprises an inner glazing (1 0h) defining an inner surface0 (1 0b) bounded by an inner glazing perimeter, parallel to an outer surface (1 0a) of an outer glazing (1 01 ), bounded by an outer glazing perimeter. The inner and outer glazings are separated from one another by at least one gap (1 31 ) defined within a peripheral spacer (1 21 ) and comprise no outer frame profile. The gap (1 31 ) can also be referred to as an interspace or a cavity. Typically, the peripheral spacer comprises a desiccant and5 has typically a thickness equal to or greater than 6 mm. In general, the gap is filled with a gas which can be selected from the group consisting of air, dry air, argon (Ar), krypton (Kr), xenon (Xe), sulfur hexafluoride (SF6), carbon dioxide or a combination thereof. Said predetermined gas are effective for preventing heat transfer and/or may be used to reduce sound transmission. The frameless sash actually comprises an inner frame profile, (1 1 ) extending over a whole perimeter of the frameless sash. The inner frame profile is lodged within a volume defined between the inner and outer glazings and between the peripheral spacer and the inner and outer perimeters. Because the inner frame profile 5 does not extend beyond the inner and outer glazing perimeters, such sashes are called frameless sashes although they do comprise a frame, albeit an inner frame profile.

[0023] The inner frame profile can be made of wood, polymer, fibre reinforced composite, or metal such as steel or aluminium. It is, however, preferred that the profile is not made of aluminium for reasons of optimized thermal insulation. The inner frame 0 profile encloses hardware required for locking / unlocking the frameless sash in an open or closed position. In a preferred embodiment, hinges for opening the frameless sash by rotation about an axis of rotation defined by the alignment of said hinges, can also be contained within the inner frame profile.

[0024] The frameless sash of the present invention has a thickness, W1 0, measured 5 normal to the outer surface and extending between the outer surface (1 0a) of the outer glazing and the inner surface (1 0b) of the inner glazing. A frameless sash is characterized by smooth inner and outer surfaces over their whole surface areas.

[0025] With the development of new building materials for the walls of buildings, the current trends in the building industry is to reduce the thickness of the walls while0 maintaining high thermal performances of the overall windows and walls. Ten years ago an average outer wall thickness was about 200 mm, when it dropped nowadays to about 1 50 mm. This has inter a/ia Xhe advantage for a building occupying a given outer area on the ground, of increasing the inner floor area defined within the walls of the building, resulting in larger rooms, In a preferred embodiment of the present invention and for5 following the trend of buildings with thinner walls, the thickness, W1 0, of the frameless sash is not more than 85 mm, preferably not more than 75 mm and more preferably not more than 70 mm.

[0026] As shown in Figure 1 , the frameless sash can comprise one intermediate glazing (1 Oi) forming a three glazing unit formed by an outer- (1 01 ), intermediate- (1 Oi = 1 02), and inner-glazing (1 0n = 1 03) separated from one another by two gaps (1 31 , 1 3i = 1 32), each gap being defined within a peripheral spacer (1 21 , 1 2 i = 1 22). In an alternative embodiment, the glazing can comprise two intermediate glazing (1 Oi) forming a four glazing unit formed by an outer- (1 01 ), first intermediate- (l Oi = 1 02), second 5 intermediate- (1 0(i + l ) = 1 03), and inner-glazing (1 0n = 1 04) separated from one another by three gaps (1 31 , 1 3i = 1 32, 1 3(i + l ) = 1 33), each one defined within a peripheral spacer (1 21 , 1 2i).

[0027] In order to hide the inner frame profile and most of the hardware enclosed therein from sight from both inner and outer environments separated by the window, the inner 0 glazing (1 On) and the outer glazing (1 01 ) preferably comprise a inner peripheral region (1 4n) and an outer peripheral region (1 41 ) extending inwardly over a height defined from an edge of the inner and outer glazings, along the whole of the inner and outer glazing perimeters, respectively, to preferably at least the peripheral spacer (1 21 , 1 2i) contacting the corresponding glazing. The inner and outer peripheral regions have a visible light 5 transmission, TL, at least 50% lower than the inner glazing (1 On) and the outer glazing (1 01 ), respectively, outside of the respective inner and outer peripheral reqions, and is preferably opaque. For example, the peripheral region can be enamelled, or etched or sand-blasted to create a texture yielding a translucent peripheral region. The peripheral region can also be made (partially) opaque or translucent by applying a film. The0 peripheral region can also comprise decorative patterns. To increase the transparent see-through area of the frameless sash (i.e., the see-through area of the window when the frameless sash is in the closed position), the height of the peripheral region, measured from an edge toward the centre of a glazing is preferably comprised between 1 0 and 1 00 mm, more preferably between 1 5 and 80 mm, most preferably, between 205 and 60 mm.

Glazing

[0028] The glazing of the present invention can consist of a single glass pane or multiple glass panes. The single or multiple glass panes can be chosen among float clear, extra- clear or coloured glass. In particular and for aesthetic purposes, the glazing can be a0 decorative glazing such as a painted or etched or sand-blasted glazing or a combination thereof. The term“glass” is herein understood to mean any type of glass or equivalent transparent material, such as a mineral glass or an organic glass. The mineral glasses used may be irrespectively one or more known types of glass such as soda-lime-silica, aluminosilicate or borosilicate, crystalline and polycrystalline glasses. The glass pane can 5 be obtained by a floating process, a drawing process, a rolling process or any other process known for manufacturing a glass pane starting from a molten glass composition. The glass pane can optionally be edge-ground. Edge grinding renders sharp edges into smooth edges which are much safer for people who could come into contact with a glass pane, in particular with the edge of frameless sash. Preferably, the glass pane according 0 to the invention is made of soda-lime-silica glass, aluminosilicate glass or borosilicate glass. More preferably and for reasons of lower production costs, the glass pane is made of a soda-lime-silica glass.

[0029] To maintain the high mechanical performance and/or to further improve the safety of the frameless sash, at least one glazing preferably consists of a single 5 pre-stressed glass pane. For example, the inner glazing (1 On) and/or the outer glazing (1 01 ) can be pre-stressed glass panes. A pre-stressed glass is a heat strengthened glass, a thermally toughened safety glass, or a chemically strengthened glass. Aluminosilicate- type glass compositions, such as for example those from the products range DragonTrail^® from Asahi Class Co. or those from the products range Gorilla^® from0 Corning Inc., are also known to be suitable for chemical tempering.

[0030] Preferably, the composition for at least one of the glass panes of the frameless sash of the present invention comprises the following components in weight percentage, expressed with respect to the total weight of glass. Comp. A is an example of a first embodiment of glass composition, and Comp. B is an example of a soda-lime-silicate-5 type glass with a base glass matrix.

[0031] Other preferred glass compositions for at least one of the glass panes of the frameless sash of the present invention comprise the following components in weight percentage, expressed with respect to the total weight of glass:

[0032] Other examples of base glass matrices for glass pane compositions suitable for the present invention are described in WO201 5 / 1 50207, WO201 5 / 1 50403

WO201 6/091 672, WO201 6/ 1 69823, and WO201 8/001 965.

[0033] In a preferred embodiment of the present invention, a glass pane can comprise 0 one or more layers such as low emissivity layers, heat ray reflection layers (solar control layers), anti-reflective layers, anti-fog layers. The one or more layers can be coated or applied as one or more films. At least one glazing (1 01 , 1 Oi, 1 On) preferably comprises a glass pane provided with a heat ray reflection layer or a low emissivity layer for improving the thermal insulating properties of the frameless sash. 5 [0034] Within the present invention and for improving the thermal insulating performance, as well as safety or acoustic performance, at least one of the glazing (1 01 , I B

l Oi, 1 0h) of the frameless sash can be a multiple glazing. In particular, the multiple glazing can be selected among a vacuum insulating glazing (VIC) to yield particularly high insulating properties, or a laminated glazing to enhance safety and acoustic performances.

5 [0035] In a preferred embodiment at least one of the glazings (1 01 , l Oi, 1 0h) of the frameless sash can be an interactive glazing. The term“interactive glazing” is herein understood to mean a glazing integrating functional elements capable of responding to an external stimulation from the environment and/or from a user. For example, the interactive glazing can integrate functional elements including one or more of an0 electrochromic, thermochromic, or photochromic device, a photovoltaic device, a multimedia connection, an antenna, communication means, a TV set, a light source including a LED, a loudspeaker, a sensor including an irradiance-, temperature-, acoustic- sensor, and the like, or a combination thereof. The electrochromic device can be controlled manually, with a switch or a remote control, or it can be coupled to a sensor 5 measuring the light irradiation and by a controller automatically controlling the voltage applied to the electrochromic device as a function of the level of irradiation.

[0036] The windows of the present invention are preferably highly energy-efficient. For this reason, it is preferred that the glazings of the frameless sash (i.e., the transparent see-through area of the frameless sash) have a thermal transmittance coefficient, Ug, of0 not more than LO W / m² K, preferably of not more than 0.7 W / m² K, or even not more than 0.5 W / m² K.

Fixed Frame

[0037] The frameless sash (1 0) is coupled to a fixed frame (20) defining a frame opening. The frame opening has an outer face bounded by an outer frame perimeter of the fixed5 frame, mating the outer glazing perimeter of the frameless sash, and has an inner face bounded by an inner frame perimeter of the fixed frame, mating the inner glazing perimeter of the frameless sash. The frame opening accommodates the frameless sash or sashes when the window is closed and brings in fluid communication the inner and outer environments when the window is open. The fixed frame is formed by one or more fixed frame profiles (21 ) made of a weathering-sensitive material such as wood or some polymers or fibre reinforced polymer composite materials (which are sensitive to UV- radiation or to hydrolysis). The fixed frame profile has an inner side facing the inner environment and comprising the inner frame perimeter of the fixed frame, and an outer 5 side facing the outer environment and comprising the outer frame perimeter of the fixed frame. The fixed frame profile has a thickness, W21 , measured normal to the outer surface (1 0a) when the frameless sash is in a closed position.

[0038] The fixed frame is provided with receiving elements for coupling the frameless sash to the fixed frame in the closed position, closing the frame opening, wherein the0 inner and outer glazing perimeters of the frameless sash are coupled to the inner and outer frame perimeters of the fixed frame, respectively. In particular, the receiving elements are designated to accommodate the hardware of the inner frame profile of the frameless sash.

[0039] The frameless sash can be fixedly coupled to the fixed frame in the closed 5 position and can be designed to not open at any moment. The fixed coupling can be reversible, in that the frameless sash can be dismounted from the fixed frame but cannot open and close like a typical window, while remaining coupled to the fixed frame.

[0040] In another embodiment, the frameless sash can be coupled to the fixed frame such that it can be reversibly moved with respect to the fixed frame (20) from a closed0 position, sealing the frame opening, to an open position, exposing part or the whole of the frame opening either

• by rotation of the frameless sash about hinges fixed to the fixed frame and defining a rotating axis parallel to the outer surface (1 0a) when the sash is in the closed position, or

5 · by translation of the frameless sash with respect to the fixed frame along a translation vector, wherein the translation vector comprises at least a first component normal to, and a second component parallel to the outer surface (1 0a) when the frameless sash is in the closed position.

[0041] The fixed frame profile (21 ), is preferably highly thermally performant. In particular, the heat transfer coefficient, Uf, of the fixed frame profile is not more than 1 .4 W / m² K, preferably not more than 0.7 W / m² K and more preferably not more than 0.5 W / m² K. Because aluminium fixed frames yield the worst heat transfer coefficients, Uf, the fixed frame profile of a window according to the present invention can be made 5 of wood, polymer, a fibre reinforced polymer composite or a combination thereof. In a preferred embodiment of the present invention, the fixed frame profile preferably has a thickness, W21 , of not more than 70 mm, preferably not more than 65 mm, more preferably not more than 60mm. Limiting the thickness of the fixed frame profile allows the available interior volume of a living space to be increased for a given external floor0 area of a building.

[0042] Because the fixed frame profile is made of a highly thermally insulating material which is generally weathering-sensitive, a cover plate (22) is coupled to and covers at least 1 0% of a surface area of the outer side of the fixed frame profile over substantially a whole of the outer perimeter of the fixed frame profile. The cover plate has the function 5 of protecting the fixed frame profile from weathering by exposure to UV and humidity.

A portion of the fixed frame profile can be embedded in the wall and therefore not exposed to the outer environment. The cover plate can therefore preferably cover up to 1 00% of the exposed surface area of the outer side of the fixed frame profile when it is mounted in a tunnel of a wall (i.e., 1 00% of the surface area which is not embedded in0 the wall). The cover plate can cover from 20 to 1 00% of the surface area of the outer side of the fixed frame profile, preferably from 30 to 90%, more preferably form 40 to 80%.

[0043] The cover plate has a thickness, W22, measured normal to the outer surface (1 0a) when the frameless sash is in the closed position. To increase the available interior volume of a living space for a given external floor area of a building, the cover plate5 thickness, W22, is preferably not more than 1 5 mm, preferably not more than 1 0 mm and more preferably not more than 7 mm.

[0044] The cover plate is used to protect the weathering-sensitive material of the fixed frame profile from aggressions by the external environment, especially UV-light, and also for protecting the fixed frame profile as well as the inner frame profile of the0 frameless sash from external moisture and water. The fixed frame has a resistance to UV higher than the resistance to UV of both fixed frame profile (21 ) and sealing elements (3), and forms a barrier against water and UV for the sealing elements (3) and at least for part of the fixed frame profile, preferably the whole of the exposed surface area of the outer side of the fixed frame (i.e. , not embedded in the wall). To fulfil these requirements, 5 the cover plate is made of a weathering-resistant material, such as a metal (e.g., aluminium or steel), UV-resistant polymers or composite materials, or ceramics.

[0045] The fixed frame has a thickness, W20, measured normal to the outer surface (1 0a) when the frameless sash is in the closed position, which is equal to the sum of the thicknesses, W21 and W22, of the fixed frame profile and of the cover plate (i.e., 0 W20 = W21 + W22). The fixed frame profile is made of a material selected for its high insulating properties, whilst the cover plate material is selected for its weathering resistance to exposure to UV and moisture and does not necessarily have good insulating properties. For guaranteeing a high thermal insulation, airtightness and a high acoustic insulation of the window of the present invention, the thickness ratio, W21 / W20, of the 5 fixed frame profile (21 ) to the fixed frame (20) is at least 80%, preferably at least 90%, more preferably at least 95%. The corollary is that the thickness ratio, W22 / W20, of the cover plate (22) to the fixed frame (20) is not more than 20%, preferably not more than 1 0%, more preferably not more than 5%.

[0046] The thickness, W20, of the fixed frame of a window of the present invention is0 equal to the thickness, W1 0, of the frameless sash, within a tolerance of ± 5% (i.e., W20 = W1 0 (1 ± 5%)), preferably of ± 2% (i.e., W20 = W1 0 (1 ± 2%)), such that when the frameless sash is in the closed position, the inner face of the fixed frame is substantially flush with the inner surface of the inner glazing (1 0h), and the outer face of the fixed frame is substantially flush with the outer surface of the outer glazing (1 01 ). With both5 inner and outer surfaces of the frameless sash being substantially flush with the inner and outer faces of the fixed frame (20) continuous smooth surfaces without any protrusion nor any significant recesses extend over the whole area of both sides of the window. Besides obvious aesthetical advantages, this configuration is particularly advantageous in terms of cleaning as, on the first hand, there are no corners, edges, etc.0 wherein dirt can accumulate and become difficult to remove and, on the second hand, the whole of both inner and outer surfaces of the window can be cleaned with a continuous movement of a squeegee, thus substantially facilitating cleaning of the window. Furthermore, since all sealing elements are internal (i.e., located between the inner and outer glazings of the frameless sash when it is in the closed position), rain 5 water or cleaning water flows over the surface of the glazing without substantially contacting any sealing element.

Sealing Elements

[0047] As shown in Figure 1 , the window of the present invention comprises sealing elements (3) for sealingly closing the frame opening when the frameless sash is in the0 closed position, i.e., when the frameless sash closes the frame opening, with the inner and outer glazing perimeters of the frameless sash being coupled to the inner and outer frame perimeters of the fixed frame, respectively.

[0048] The sealing elements can be mounted on the fixed frame, e.g., at an inner edge of the fixed frame profile which is transverse to the inner and outer sides of the fixed5 frame profile, and/or at the cover plate. Alternatively, or concomitantly, the sealing elements can be mounted on the frameless sash at an outer edge transverse to the inner and outer surfaces. When the frameless sash is in the closed position, the sealing elements are deformed as the outer edge of the frameless sash fits into the mating inner edge of the fixed frame, thus forming a seal between the fixed frame and the frameless0 sash when the latter is in the closed position.

Coupling of the Frameless Sash to the Fixed Frame

[0049] The fixed frame comprises receiving elements for coupling the frameless sash to the fixed frame in the closed position, closing the frame opening. As mentioned supra, the frameless sash can be fixedly coupled to the fixed frame, in that the frameless sash5 cannot be open and closed easily (it can possibly be removed from the fixed frame but cannot open the frame opening while still coupled to the fixed frame).

[0050] In a preferred embodiment, the frameless sash is movingly coupled to the fixed frame such that the frameless sash can reversibly move with respect to the fixed frame (20) from the closed position to an open position wherein the frameless sash leaves open at least a portion of the frame opening, with the frameless sash remaining coupled to the fixed frame.

[0051] Figure 2 illustrates different possible configurations of the present invention. Figure 2(a) shows a window according to the present invention (actually a sliding 5 glass-door), comprising a fixed frameless sash (1 Of) and a moving frameless sash (1 0m).

The moving frameless sash can reversibly move with respect to the fixed frame (20) from the closed position to the open position by translation of the frameless sash with respect to the fixed frame along a translation vector. The translation vector comprises at least a first component normal to the outer surface (1 0a) when the frameless sash is in the 0 closed position, in order to offset the moving frameless sash onto a different plane than the fixed sash. It also comprises a second component parallel to the outer surface (1 0a) when the frameless sash is in the closed position, to slide the moving sash (1 0m) parallel to the fixed sash until they are substantially facing each other. To close the sliding glass- door, it suffices to slide the moving sash back along the second component of the 5 translation vector until it does not overlap anymore with the fixed sash, and then push or pull it back along the first component to bring the moving sash on the same plane as the fixed sash and thus close the frame opening in the closed position.

[0052] Figure 2(b) shows a casement window (it could be a glass-door if the frameless sashes extend to the floor), comprising two moving frameless sashes mounted on hinges0 aligned such as to define vertical axes of rotation. This window design can also be referred to as "stulp.” The triangles in dashed lines indicate the direction of opening, with the summit indicating the edge opposite to the hinges and moving away from the fixed frame and the (vertical) base indicating the axis of rotation defined by the positions of the hinges. Figure 2(c) shows a similar casement window as in Figure 2(b) but comprising5 a single frameless sash instead of two frameless sashes.

[0053] Figure 2(d) shows a tilting frameless sash coupled to the fixed frame by hinges located at the lower horizontal edge of the fixed frame. The top edge of the frameless sash can thus be moved away from the top edge of the fixed frame by rotation about a horizontal rotating axis. Most tilting sashes can also be opened by rotation about a0 vertical axis of rotation as discussed with respect to Figure 2(c), thus combining both modes of opening. Such windows are called“tilt and turri’ windows.

[0054] In a particular embodiment and as clearly illustrated in Figure 1 , it is preferred that the frameless sash is movingly coupled to the fixed frame and the inner glazing perimeter of the frameless sash is larger than the outer glazing perimeter, with a projection of the outer glazing perimeter onto the outer surface being comprised within a projection of the inner glazing perimeter. Of course, the fixed frame has a matching geometry with a larger inner perimeter of the frame opening than the outer perimeter of the frame opening. This gives the great advantage of enhancing sealing of the interface between the frameless sash and the fixed frame. Indeed, as illustrated in Figure 1 , several surfaces of both sash and fixed frame, which are substantially parallel to the outer surface, when the frameless sash is in the closed position, can thus face each other and abut when the frameless sash in the closed position. By providing sealing elements between two such facing and abutting surfaces, a tight sealed contact can be formed between the frameless sash and the fixed frame. [0055] The slope formed by a straight line extending between the inner glazing perimeter and the recessed outer glazing perimeter is preferably comprised between 30° and 60° and is preferably equal to 45°± 5° for optimizing the sealing contact between the frameless sash and fixed frame. The same applies for stulp windows, wherein central vertical edges of two frameless sashes contact as illustrated in Figure 2(b). It can be seen in Figure 2(b), that contrary to the frameless sash on the left-hand side characterized by a trapezoidal cross-section according to the discussion supra, the frameless sash on the right-hand side has a parallelogram cross-section, with the inner glazing perimeter being recessed with respect to the outer glazing perimeter at the level of the central vertical edge contacting the left-hand side sash in the closed position. This way, the central vertical edges of the two sashes sealingly meet and mate in the closed position.

[0056] A further advantage of designing a window with the frameless sash and fixed frame being flush along both inner and outer surfaces is the enhancement (i.e., increase) of the opening ratio, A0 = Af / At, of the area of the frame opening to the area of the tunnel in the wall. The opening ratio defines the fraction of a given tunnel area which is masked by the fixed frame. The higher this fraction, the more efficient is the window. To date, in frameless sashes coupled to fixed frame profiles provided with cover plates, the cover plates overlap with the frameless sash, generally for supporting a sealing element squeezed between the cover plate and the outer surface of the frameless sash when it is in the closed position. The free ridge of the cover plate (i.e., bounding the outer perimeter 5 of the frame opening) is therefore the innermost structure of the fixed frame defining the perimeter of the frame opening. The frame opening area is therefore necessarily smaller than the outer surface area and when the frameless sash is opened, the frame opening is smaller than could be expected in view of the dimensions of the frameless sash. This is clearly visible in the Figures of EP3228795 , EP2436865, or EP2436865. 0 [0057] By contrast, with the present invention, the frame opening has the same area as the outer surface. When the frameless sash is in the open configuration, the frame opening thus exposed has same area as the frameless sash, thus increasing the opening ratio with respect to a fixed frame comprising a cover plate overlapping the frameless sash. This effect is far from being negligible. For example, a cover sheet overlapping with 5 the outer glazing perimeter by merely 1 cm, reduces the opening ratio by about 4% for a small dimension 1 00 x 1 00 cm frameless sash, and by about 8% for a 200 x 200 cm frameless sash, compared with a cover plate flush (i.e., not overlapping) with the frameless sash.

[0058] In a preferred embodiment, the window comprises a mechanically, pneumatically0 or electrically actuating device for reversibly moving the frameless sash (1 0) with respect to the fixed frame (20) from the closed position to the open position and reverse. The actuating device can be activated with a switch located on the window or on the wall (30) supporting the window. Alternatively, or additionally, the actuating device can be activated by means of a remote-control system, including a receiver integrated in the5 frameless sash and/or the fixed frame for actuating the moving of the frameless sash.

The remote-control system can preferably also control any functionality of the glazing as discussed supra in the section entitled“glazing”, such as an electrochromic device, a multimedia connection, an antenna, communication means, a TV set, a light source including a LED, a loudspeaker, a sensor, and the like. 0 Window Assembly

[0059] The window of the present invention is used for allowing light to pass through an opening in a wall. In many cases, a window can be opened to bring in fluid communication inner and outer environments separated from one another by said wall. To this purpose, 5 the wall (30), which separates the inner environment from the outer environment, is provided with a through opening in the form of a tunnel (30t) defined by a tunnel perimeter. The fixed frame (20) is sealingly coupled to the tunnel perimeter, with the inner face of the fixed frame facing the inner environment and the outer face of the fixed frame facing the outer environment. When the frameless sash is in the closed position, 0 the inner environment is separated from the outer environment by the window.

[0060] The opening ratio, A0 = Af / At, defined above, wherein Af, and At are the areas of the frame opening and of the tunnel, respectively, depends on the dimensions of the fixed frame. The opening ratio decreases with an increase of the fixed frame height, measured parallel to the outer surface of the outer glazing when the frameless sash is in 5 the closed position. Conversely, the lower the height of the fixed frame, the higher the value of the opening ratio.

[0061] The wall (30) has a thickness, W30, measured normal to the outer surface (1 0a) of the outer glazing when the frameless sash is in the closed position. The thickness, W30, of the wall can be greater than or equal to the thickness, W20, of the fixed frame,0 W30 > W20. In a preferred embodiment, the inner face of the fixed frame is flush with the wall at the inner environment as illustrated in Figure 2(b)&2(c). In an alternative embodiment illustrated in Figure 2(a), 2(c), and 2(d), the outer face of the fixed frame is flush with the wall at the outer environment. In yet a preferred embodiment, for particularly thin walls and for increasing the available interior volume of a living space5 for a given external floor area of a building, both inner and outer faces of the fixed frame are flush with the wall at the inner and outer environments, as illustrated in Figure 2(c).

[0062] The present invention concerning a window comprising a frameless sash coupled to a fixed frame comprising a fixed frame profile made of a weathering-sensitive material, which outer side is protected by a cover plate, and wherein both inner and outer surfaces of the frameless sash are flush with the inner and outer faces of the fixed frame

(includ ing the cover plate), provides particularly aesthetic design opportunities, which have the advantage of low amounts of dirt accumulation and, at the same time, easier cleaning of the window, since both inner and outer surfaces of the window form a continuous smooth surface with no protrusions or recesses where the d irt can accumulate, and which can be cleaned with a continuous driving of a sq ueegee over the surfaces. The opening ratio, AO, is also enhanced with the present invention.

Claims

1 . A window comprising,

(a) A frameless sash (1 0) comprising

• an inner glazing (1 0h) defining an inner surface (1 0b) bounded by an inner

5 glazing perimeter, parallel to an outer surface (1 0a) of an outer glazing (1 01 ), bounded by an outer glazing perimeter, the inner and outer glazings being separated from one another by at least one gap (1 31 ) defined within a peripheral spacer (1 21 ) and comprising no outer frame profile,

• an inner frame profile (1 1 ) lodged within a volume defined between the inner 0 and outer glazings and between the peripheral spacer and the inner and outer perimeters,

wherein the frameless sash has a thickness, W1 0, measured normal to the outer surface and extending between the outer surface (1 0a) of the outer glazing and the inner surface (1 0b) of the inner glazing, 5 (b) A fixed frame (20) defining a frame opening having an outer face bounded by an outer frame perimeter mating the outer glazing perimeter and an inner face bounded by an inner frame perimeter mating the inner glazing perimeter, said fixed frame comprising,

• a fixed frame profile (21 ) having an inner side and an outer side, and having a thickness, W21 , measured normal to the outer surface (1 0a) when the frameless0 sash is in a closed position,

• receiving elements for coupling the frameless sash to the fixed frame in the closed position, closing the frame opening, wherein the inner and outer glazing perimeters of the sash are coupled to the inner and outer frame perimeters of the fixed frame, respectively,

5 · a cover plate (22) coupled to and covering at least 1 0% of a surface area of the outer side of the fixed frame profile over substantially a whole of the outer frame perimeter, said cover plate having a thickness, W22, measured normal to the outer surface (1 0a) when the sash is in the closed position, wherein the fixed frame (20) has a thickness, W20, measured normal to the outer surface (1 0a) when the sash is in the closed position, which is equal to the sum of the thicknesses, W21 and W22, of the fixed frame profile and of the cover plate (i.e., W20 = W21 + W22),

5 (c) Sealing elements (3) mounted on the fixed frame and /or on the frameless sash to form a seal between the fixed frame and the sash when the latter is in the closed position, for sealingly closing the frame opening when the sash is in the closed position, characterized in that,

• the thickness, W20, of the fixed frame is equal to the thickness, W1 0, of the frameless 0 sash, within a tolerance of ± 5%, preferably of ± 2%, in that

• when the frameless sash is in the closed position, the inner face of the fixed frame is flush with the inner surface of the inner glazing (1 On), and the outer face of the fixed frame is flush with the outer surface of the outer glazing (1 01 ), and in that

• the thickness ratio, W21 / W20, of the fixed frame profile (21 ) to the fixed frame (20) is 5 at least 80%, preferably at least 90%.

2. Window according to claim 1 , wherein the receiving elements are suitable for coupling the frameless sash to the fixed frame in one of the following manners,

• the frameless sash is fixedly coupled to the fixed frame in the closed position, or

• the frameless sash is movingly coupled to the fixed frame such that the frameless sash0 can reversibly move with respect to the fixed frame (20) from the closed position to an open position wherein the frameless sash leaves open at least a portion of the frame opening, either

o by rotation of the frameless sash about hinges fixed to the fixed frame and defining a rotating axis parallel to the outer surface (1 0a) when the frameless5 sash is in the closed position, or

o by translation of the frameless sash with respect to the fixed frame along a translation vector, wherein the translation vector comprises at least a first component normal to, and a second component parallel to the outer surface

(1 0a) when the frameless sash is in the closed position.

3. Window according to claim 1 or 2, wherein the fixed frame profile (21 ),

• is made of wood, polymer, a fibre reinforced polymer composite or a combination

5 thereof, and/or

• has a frame heat transfer coefficient, Uf, of not more than 1 .4 W / m² K, and /or

• has a thickness, W21 , of not more than 70 mm, preferably not more than 65 mm and more preferably not more than 60mm.

4. Window according to any one of the preceding claims, wherein the cover plate (22) is 0 made of metal, a UV-resistant polymer or a UV-resistant fibre-reinforced polymer composite, said cover plate having a resistance to UV higher than the resistance to UV of both fixed frame profile (21 ) and sealing elements (3), and forming a barrier against water and UV for the sealing elements (3) and at least for part of the fixed frame profile.

5. Window according to claim 4, wherein the thickness, W22, of the cover plate (22) is not 5 more than 1 5 mm, preferably not more than 1 0 mm and more preferably not more than 7 mm.

6. Window according to any one of the preceding claims, wherein the frameless sash comprises either,

• one intermediate glazing (1 Oi) forming a three glazing unit formed by an outer- (1 01 ), intermediate- (1 Oi = 1 02), and inner-glazing (1 On = 1 03) separated from one another0 by two gaps (1 31 , 1 3i = 1 32), each gap being defined within a peripheral spacer (1 21 ,

1 2i = 1 22), or

• two intermediate glazing (l Oi) forming a four glazing unit formed by an outer- (1 01 ), first intermediate- (1 Oi = 1 02), second intermediate- (1 0(i + l ) = 1 03), and inner-glazing (1 On = 1 04) separated from one another by three gaps (1 31 , 1 3 i = 1 32,5 1 3(i + l ) = 1 33), each one defined within a peripheral spacer (1 21 , 1 2i).

7. Window according to any one of the preceding claims, wherein the frameless sash is movingly coupled to the fixed frame and wherein the inner glazing perimeter is larger than the outer glazing perimeter, and wherein in a projection onto the outer surface, the outer glazing perimeter is comprised within the inner glazing perimeter.

8. Window according to any one of the preceding claims wherein the inner glazing (1 On) and the outer glazing (1 01 ) comprise an inner peripheral region (1 4n) and an outer peripheral region (1 41 ) extending inwardly from an edge of the inner and outer glazings, along the whole of the inner and outer glazing perimeters, respectively, to preferably at least the peripheral spacer (1 21 , 1 2 i) contacting the corresponding glazing, wherein the inner and outer peripheral regions have a visible light transmission, TL, at least 50% lower than the inner glazing (1 On) and the outer glazing (1 01 ), outside of the respective inner and outer peripheral reqions, and is preferably opaque.

9. Window according to any one of the preceding claims, wherein at least one glazing (1 01 , 1 Oi, 1 On) is provided with at least a heat ray reflection film or a low-emissivity film.

1 0. Window according to any one of claims 2 to 9, comprising a mechanically, pneumatically or electrically actuating device for reversibly moving the frameless sash (1 0) with respect to the fixed frame (20) from the closed position to the open position.

1 1 . Window according to any one of the preceding claims, wherein at least one of the glazing (1 01 , l Oi, 1 On) is an interactive glazing, preferably selected among an electrochromic, thermochromic, or photochromic device, a photovoltaic device, a multimedia connection, an antenna, communication means, a TV set, a light source including a LED, a loudspeaker, a sensor including an irradiance-, temperature-, or acoustic- sensor,, or a combination thereof.

1 2. Window according to claim 1 0 or 1 1 , comprising a remote-control system, including a receiver integrated in the frameless sash and /or the fixed frame for actuating the moving of the frameless sash or a functional element. I B. Window according to any one of the preceding claims, wherein the glazings of the frameless sash have a thermal transmittance coefficient, Ug, of not more than 1 .0 W / m² K, preferably of not more than 0.7 W / m² K.

1 4. Assembly comprising:

5 · a wall (30) separating an inner environment from an outer environment and provided with a through opening in the form of a tunnel (30t) defined by a tunnel perimeter, and • at least a window according to any one of the preceding claims, wherein the fixed frame (20) is sealingly coupled to the tunnel perimeter, with the inner face of the fixed frame facing the inner environment and the outer face facing the outer environment, such0 that the inner environment is separated from the outer environment by the window when the frameless sash is in the closed position.

1 5. Assembly according to claim 1 4, wherein the wall (30) has a thickness, W30, measured normal to the outer surface (1 0a) when the frameless sash is in the closed position, which is greater than or equal to the thickness, W20, of the fixed frame, W30 > W20, and wherein the 5 inner face of the fixed frame is preferably flush with the wall at the inner environment and/or the outer face of the fixed frame is preferably flush with the wall at the outer environment.