Glazing Assembly

Abstract

A glazing assembly is disclosed, the assembly comprising first and second toughened glass members. Each member comprises a sheet with first and second flanges projecting from opposite ends of the sheet in a direction substantially perpendicular to the sheet, and the first and second flanges of the first member are joined respectively to the first and second flanges of the second member by first and second connector portions such that the first and second flanges of the first member are substantially coplanar with the first and second flanges of the second member, respectively. A modular glazing array is also disclosed. The array comprises a plurality of glazing assemblies arranged side by side, such that at least one pair of joined, coplanar flanges of each of the plurality of glazing assemblies faces a pair of joined, coplanar flanges of another of the plurality of glazing assemblies.

Claims

1. A glazing assembly comprising: first and second toughened glass members, each member comprising a sheet with first and second flanges projecting from opposite ends of the sheet in a direction substantially perpendicular to the sheet, wherein the first and second flanges of the first member are joined respectively to the first and second flanges of the second member by first and second connector portions such that the first and second flanges of the first member are substantially coplanar with the first and second flanges of the second member, respectively.

2. The glazing assembly according to claim 1, wherein each connector portion comprises first and second channels, and is disposed between two opposing flanges such that an edge of a flange of each of the first and second members is held within each of the first and second channels, respectively.

3. The glazing assembly according to claim 1, wherein each connector portion is disposed along two opposing flange edges of the first and second members.

4. The glazing assembly according to claim 1, wherein each connector portion comprises a thermal insulator.

5. The glazing assembly according to claim 1, wherein each connector portion is bonded to an edge of a flange of each of the first and second members by an adhesive.

6. The glazing assembly according to claim 1, wherein the dimensions of the first member are substantially the same as those of the second member.

7. The glazing assembly according to claim 1, wherein for each member the depth of each flange is between approximately 8% and 30% of the width of the sheet.

8. The glazing assembly according to claim 1, wherein for each member the height of the sheet is greater than 3.3 m, and the width of the sheet is approximately 10% of the height of the sheet.

9. The glazing assembly according to claim 1, wherein the members are attached together so as to define a tube having a substantially rectangular cross section, with sides defined by the flanges and sheets of the first and second members.

10. The glazing assembly according to claim 9, further comprising a closure sealing an end of the tube.

11. The glazing assembly according to claim 1, wherein the volume between the first and second members comprises a thermal insulator.

12. The glazing assembly according to claim 1, wherein the volume between the first and second members comprises an acoustically insulating material.

13. The glazing assembly according to claim 1, wherein the volume between the first and second members comprises a material through which light is diffusely transmitted.

14. The glazing assembly according to claim 11, wherein the material comprises glass fibre.

15. The glazing assembly according to claim 1, wherein an outer surface of a sheet of the assembly comprises a plurality of grooves aligned substantially parallel to the flanges of the assembly.

16. The glazing assembly according to claim 1, wherein an outer surface of a sheet of the assembly has a rough profile which scatters light transmitted through the surface.

17. The glazing assembly according to claim 1, further comprising an internal protective element.

18. The glazing assembly according to claim 17, wherein the internal protective element is formed from a polycarbonate material.

19. The glazing assembly according to claim 17, wherein the internal protective element comprises a sheet portion that is substantially coplanar with the sheet of the first and second members and spans the interior volume defined by the first and second members.

20. A method of producing a glazing assembly, the method comprising: providing first and second toughened glass members, each member comprising a sheet with first and second flanges projecting from opposite ends of the sheet in a direction substantially perpendicular to the sheet, and joining the first and second flanges of the first member respectively to the first and second flanges of the second member using first and second connector portions such that the first and second flanges of the first member are substantially coplanar with the first and second flanges of the second member, respectively.

21. The method according to claim 20, wherein each connector portion comprises first and second channels, and the method further comprises disposing each connector portion between two opposing flanges such that an edge of a flange of each of the first and second members is inserted into and held within each of the first and second channels, respectively.

22. The method according to claim 20, further comprising disposing each connector portion along two opposing flange edges of the first and second members.

23. The method according to claim 20, further comprising bonding each connector portion to an edge of a flange of each of the first and second members using an adhesive.

24. the method according to claim 20, comprising attaching the members together so as to define a tube having a substantially rectangular cross section, with sides defined by the flanges and sheets of the first and second members, and further comprising sealing an end of the tube with a closure.

25. A modular glazing array comprising: a plurality of glazing assemblies according to claim 1 arranged side by side, such that at least one pair of joined, coplanar flanges of each of the plurality of glazing assemblies faces a pair of joined, coplanar flanges of another of the plurality of glazing assemblies.

26. The modular glazing array according to claim 25, wherein the plurality of glazing assemblies comprises three or four glazing assemblies, and wherein the modular glazing array comprises a window within the module.

27. The modular glazing array according to claim 25, wherein a sealant is disposed between adjacent assemblies.

28. The modular glazing array according to claim 25 wherein the normal vectors of the sheets of adjacent assemblies differ by no more than 10.

29. The modular glazing array according to claim 25, wherein the sheets of each of the plurality of assemblies are substantially parallel.

30. A method of installing a glazing assembly according to claim 1, the method comprising: providing a front-loading carrier for receiving the glazing assembly, the carrier comprising a frame having a height corresponding to that of the assembly, a surrounding lip on a rear side of the carrier, and a removably mounted lip on the front side of the carrier, inserting the glazing assembly into the frame from the front side when the removable lip is removed, and mounting the lip on the carrier such that the assembly is prevented from being removed from the frame.

31. A method of installing a modular glazing array according to claim 25, the method comprising: providing a front-loading carrier for receiving the modular glazing array, the carrier comprising a frame having a size and shape corresponding to the height of the array, a surrounding lip on a rear side of the carrier, and a removably mounted lip on the front side of the carrier, inserting the array into the frame from the front side when the removable lip is removed, and mounting the lip on the carrier such that the array is prevented from being removed from the frame.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Examples for the present invention will now be described, with reference to the accompanying drawings, wherein like reference numerals indicate like features, and in which:

[0088] FIG. 1 is a cross section of an example glazing assembly according to the invention;

[0089] FIGS. 2A to 2C show two exploded views and a perspective view of the example glazing assembly according to the invention;

[0090] FIG. 3 is a table containing comparative data indicating various properties of the example glazing assembly according to the invention and glazing assemblies of the prior art;

[0091] FIGS. 4A and 4B show a perspective view and a cross section of an example modular glazing array according to the invention;

[0092] FIGS. 5A and 5B show a perspective view and a cross section, respectively, of a glazing assembly carrier and installation method according to the prior art;

[0093] FIG. 6 is a photograph showing a cross section of part of a front loading carrier for receiving a glazing assembly or modular glazing array according to the invention;

[0094] FIGS. 7A and 7B show a cross section and a perspective view, respectively, of the installation of a modular glazing array according to the invention in a front-loading carrier;

[0095] FIG. 8 is an elevation showing part of a building comprising modular glazing arrays according to the invention seen from the exterior; and

[0096] FIGS. 9A and 9B respectively show a horizontal cross section and a vertical cross section of an example modular glazing array according to the invention wherein the assembly comprises an internal protective element.

DESCRIPTION OF EMBODIMENTS

[0097] Referring to FIGS. 1 to 3, an example glazing assembly according to the invention is now described. Glazing assembly 101 comprises first and second glass U-channels 103, 104. The first U-channel member 103 comprises a planar sheet 115 with first and second perpendicular flanges 117A, 117B which project orthogonally from either side of the sheet 115 and terminate at first and second flange edges 119A, 119B, respectively. Each U-channel is made from low iron cast glass which is enamelled on the inner inside face. In the present example the project-specific width of each U-channel is 404 mm, as measured between opposite outer faces 125, 126 of first and second flanges 117A and 117B. The thickness of the glass, as measured between outer 127 and inner 128 it faces of sheet 115 is 8 mm. The glass is toughened, heat-soak tested cast glass, with enamelled frit on the inner inside face.

[0098] The tensile strength values for the toughened cast glass of the member 103 are 50 Nmm.sup.2 for the sheet in the tension zone, and 115 Nmm.sup.2 for a flange 117A, 117B in the tension zone.

[0099] The compressive strength of the glass is approximately 1,000 Nmm.sup.2. This means that the applied compressive load required to shatter a 1 cm cube of the glass is 10 tonnes.

[0100] When a plane of glass is deflected, one of its faces is subjected to compression, while the other face is in tension. The resistance of the toughened glass to compressive stress is considerably greater than its resistance to tensile stress.

[0101] The resistance of the toughened glass of the member 103 to breakage on deflection is 110-200 Nmm.sup.2. The upper end of this range corresponds to both faces of the sheet having high compressive strength imparted by the glass toughening process. The precise value is dependent upon the thickness, edgework, holes, and notches which may be applied to the member in different variations.

[0102] By contrast, the equivalent resistance value for annealed glass is in the order of 40 Nmm.sup.2.

[0103] Likewise, the second U-channel member 104 is formed from toughened glass, and comprises a central, planar sheet 116 and perpendicular, opposing flanges on either side 118A, 118B. The two U-channels are placed in a flange-to-flange arrangement wherein the edges 119A, 20A of first flanges 117A, 118A of the first and second member 103, 104 are opposing and aligned with each other.

[0104] Similarly, the edges 119B, 120B of second flanges 117B, 118B of the first and second member 103, 104 are also aligned and opposing one another. The first and second U-channels are bonded together by first and second connectors 105, 106. The first connector 105 comprises first and second channels 130A, 130B adapted to receive an edge portion of a U-channel flange. The first and second U-channels are held together by the first and second flanges 117A, 117B of first member 103 being held within the first channels 130A, 131A and first and second flanges 118A, 118B of the second member 104 being held within second channels 130B, 131 B, of the first and second connectors 105, 106, respectively.

[0105] Each connector 105, 106, comprises a fibre-reinforced polyamide thermal extrusion. The polyamide extrusion connector 105, 106 is a TECATHERM 66 GF thermally insulating profile section, comprising polyamide 66 with 25.0 plus or minus 2.5% by weight glass fibres. This may provide a strength of greater than or equal to 110 MPa, a modulus of elasticity in tension of greater than or equal to 6000 MPa, and a thermal conductivity of 0.28 W/m.sup.2K, according to testing standards DIN 53455, 53457, and 52612 respectively. Each bonded flange is held in place with a connector by a respective portion of adhesive 110A, 110B, 111A, 111B, which comprises Dow Corning 993 white structural silicone. Thus the two U-channels are unitised by bonding the flanges into these double-sided bespoke polyamide extrusions 105, 106.

[0106] Empirical tests have shown the effective area moment of inertia of the assembly of the present example to be 420 cm.sup.4. Therefore, a 300% increase in the area moment of inertia is provided with respect to the comparative assembly comprising rubber connectors mentioned above.

[0107] The colour of the polyamide extrusion 105, 106 is refracted through the flange of the U-channel profiles 103, 104. Therefore, the colour of the extrusions should be selected appropriately.

[0108] The overall depth of the assembly, that is between outer faces 127 and 132 of the first and second sheet 115, 116 is 144 mm. The additional depth provided by this arrangement significantly increases the vertical span achievable by the

[0109] U-channel, because the two U-channels are structurally bonded and act in unison. With a typical wind load requirement of 1.5 kN/m.sup.2, a single cast glass U-channel 262 mm wide will achieve a vertical span in excess of 7 m [7 m is generally the longest length of U-channel manufactured within acceptable tolerances, therefore the designer has more freedom with the width of a single U-channel, considering that the wider the U-channel, the shorter the achievable vertical span]. The volume between the two members is filled with Wacotech TIMax GL translucent glass fibre insulation 113. The insulation is installed in the factory at the same time as the bonding of the flanges together. By doing this off-site, that is prior to the delivery of the glazing assembly to the site where it is to be installed, the amount of contamination is minimised during the encapsulation process.

[0110] The assembly process is illustrated at several stages in FIGS. 2A to 2C. The exploded view shown in FIG. 2A contains the elements previously described, as well as Forex thermoformed top and bottom caps 123, 124, in a disassembled state. In FIG. 2B, the first and second U-channels 103, 104 have been bonded together with first and second connectors 105, 106, so as to partially enclose glass fibre insulation 113. This optically white translucent insulation is hung and held at the top in slight compression. This provides the assembly with thermal performance and light transmission levels which provide a quality of diffused white natural light to the interior of a building in which the glazing is installed. The translucent envelope also offers users privacy, and alleviates issues of overlooking that are associated with densely populated, urban environments.

[0111] The height, width, and depth axes which are used to refer to the dimensions of the assembly are indicated in the present figure by the letters H, W, and D, respectively. The relative dimensions of the assembly shown in the present figure are not to scale. Furthermore, although the edges between the flanges 117, 118 and the sheets 115, 116 are illustrated as having a sharp or defined edge, in practice these generally comprise rounded edges, owing to the nature of the casting process and the increased strength or decreased vulnerability which may be achieved by incorporating a more rounded corner to the U-channel profile.

[0112] In assembling the cast glass unit 101, when the U-channels 103, 104 have been attached together in a toe-to-toe arrangement using the two-part structural silicone (not shown) to bond the U-channels with the polyamide extrusions 105, 106, as shown in FIG. 2B, closure caps 123 and 124 are applied to the top and bottom apertures 134, 136 of the approximately rectangular tubular assembly 101. This sealing of the top and bottom edges of the unit with purpose-made thermoformed caps 123, 124 is shown in FIG. 2C. The bottom cap 124 contains a weep hole 137 including an interior insect mesh 138. This provides an outlet for condensation run-off and pressure equalisation of the unit. The resulting, complete cast glass unit 101 is able to be used with a wind load criterion in excess of 2.5 kN/m.sup.2 for a span of 4.2 m, owing to the increased structural strength provided by the toe-to-toe arrangement. This removes the need for any vertical framing or additional vertical support. Glazing assemblies with dimensions corresponding to those indicated in the final column of the table of FIG. 3 have been tested successfully for a 4.2 m vertical span under these conditions. The novel arrangement overcomes the limitations of cast glass U-channels and achieves this vertical span without intermediate support with an overall faade thickness of only 144 mm. Additionally, the structural capabilities of the glazing assembly are particularly beneficial in sections with windows and door openings. The cast glass unit is able to carry the load of a 2000 mm808 mm triple glazed window unit without any additional support, rendering it an integrated cladding element. The glazing assembly structurally supports openable triple glazed windows, and openings with no additional vertical support. The unitised system is adaptable to include additional layers of security to protect against intrusion, by way of hard body impact resistance.

[0113] The assembly represents an innovation in large unitised structural, toughened U-channel cast glass elements that have been fabricated and sealed off-site and installed on-site in modules, thus maintaining quality of workmanship, especially in the silicone, while facilitating a faster on-site installation than any previous U-channel cast glass faade.

[0114] A comparison of the present example of the glazing assembly of the present invention with conventional assemblies available in the prior art is shown in the table of FIG. 3. In particular, columns 1 and 2 contain data relating to the interlocked assemblies, excluding and including interior insulation respectively, wherein U-channels are assembled together with their flanges overlapping and interlocking with one another, rather than being bonded in an edge-to-edge arrangement. The third column indicates the properties of a prior art glazing arrangement wherein two independent layers or tracks of single layer glass U-channels are provided. The final column contains test data for the presently described example of the glazing assembly according to the invention.

[0115] In view of this figure, the limitations of the prior art glazing approaches and the relative advantages now provided may be seen. Using a typical wind load requirement of 1.5 kN/m.sup.2, the interlocked arrangement achieves a vertical span of 3.27 m with 262 mm-wide toughened U-channels, or 2.94 m with 330 mm-wide toughened U-channels. This is as compared to a vertical span in excess of 7 m for the equivalent assembly when arranged according to the present arrangement.

[0116] The interlocking assembly also suffers from thermal insulation limitations, as can be seen from the higher U-values achieved by the assemblies illustrated in the first two columns when compared with that of the present arrangement as shown in the final column. The lack of thermal breaks or isolation with the interlocking assembly, in addition to the requirement of this type of assembly for horizontal and vertical carriers which may themselves conduct heat, makes the channels susceptible to condensation. By providing weep holes in the carrier to drain condensation, there would be a risk of insect penetration introduced, which may be difficult to address owing to the lack of access for cleaning the interior of the assemblies.

[0117] With regard to wind suction, the interlocked assembly is typically supported by top and bottom horizontal carriers. Additional wind anchors or intermediate support to the vertical spans may be used, however these are limited. This is especially the case if the interlocked system is to be used in areas of high wind loads, or at significant height, as the mid-span is held in place only by weathering silicone joints.

[0118] The edges of the U-channels are, as is the case with most glass, and in particular toughened glass, the most susceptible to damage which results in total failure. The interlocked system provides no protection in the case of an impact as the deflection causes the glass of the outer face of one flange to impact or contact the flange of an adjacent U-channel, which may cause failure. The present arrangement alleviates the risk of such impact-induced failure, owing to the first member 103 being separated from, and therefore not contacting upon an impact to one of the sheets 115, for instance, the second member 104.

[0119] In architectural applications, it is preferable for width-to-height ratios of approximately 1 to 10 to be achieved, and this is possible with cast glass U-channel units. Therefore, when the requirement is for a vertical span of 4.2 m, corresponding to a typical floor-to-floor distance on a building, a 262 mm or 330 mm-wide U-channel is not preferable, as these widths are too narrow to achieve the desired proportions. The present arrangement facilitates the creation of cast glass U-channel units that correspond to this desired aspect ratio. Furthermore, by providing a U-channel assembly with increased width, the number of joints between adjacent U-channels arranged side-by-side on a faade, for example is reduced.

[0120] Cast glass is not optically clear. However, glass fibre insulation may still be visible through the glass of a U-channel when pressed up against its interior surface. In order to achieve a light-diffusing finish, and render these fibres invisible to an exterior viewer, various finishes may be applied to the inside face of the U-channels which manufacturers of the U-channel offer.

[0121] The outside face 132 of sheet 116 is provided with a plurality of millimetre-scale grooves in a repeating pattern. The grooves run the entire height of the sheet 116, and are aligned with the height axis. Thus the assembly is suitable for installation in a building with the second member 104 as the outer, or exterior-facing member, such that the grooves are aligned vertically and can provide a self-cleaning function.

[0122] The interior-facing sheet 103 has a roughened, solar surface profile applied to the outer face 127. This presents to building occupants, a surface texture which diffuses light passing through the sheet 103 and renders the fibres of insulation 113 indistinguishable or invisible, and upon which it is possible to write and draw using marking pens.

[0123] The nature of the interlocked assembly, and other assemblies, limits the geometry that can be achieved with a U-channel envelope. The nature of the installation of the assemblies in a linear arrangement or on a single curve with limited radius and the interlocked arrangement are not suited for windows and openings if they are not structurally independent from the U-channels. These elements shall require vertical framing to bridge the gap between the two systems. The structural capability provided by the present arrangement alleviates this issue.

[0124] The comparison shown in FIG. 3, which assumes one particular insulation material and one type and width of U-channel glass, clearly illustrates the advantageous properties provided by the phasing assembly of the present example glazing assembly. The results show that the thermal performance of the glazing envelope, its ability to diffusively transfer daylight and avoid non-beneficial solar gains are critical to helping to achieve compliance with current UK regulations. It also means that the thermal efficiency and comfort of occupants of a building is achieved for those in close proximity to the building envelope without requiring perimeter heating.

[0125] The light transmission at 11% provides a diffused white natural illumination to the interior. In the present example, an illuminance level of 300 lux may be achieved given an overcast sky, at a distance of 4 m back from the interior of a faade comprising the example glazing assembly. The present example glazing assembly removes the glare, and strong, dazzling light to which occupants of buildings utilising prior art glazing assemblies may be subjected. This is particularly beneficial in relation to occupants viewing computer displays. The translucent envelope additionally offers privacy and alleviates overlooking issues associated with inner city densities.

[0126] An example modular glazing array comprising a plurality of glazing assemblies according to the invention is shown in FIGS. 4A and 4B. These drawings show a perspective and cross section view, respectively. The array 202 comprises four glazing assemblies 201, 201, 201 etc., each of which is similar to the example assembly described above. In the present example, five assemblies are shown as being attached in a linear arrangement such that the sheets 216, 216, 216 etc. are substantially coplanar. It is additionally envisaged that alternative arrays may be provided, which may contain different numbers of constituent assemblies, and which may be arranged so as to be aligned in curved as well as straight alignment.

[0127] Nominally 9 mm-wide weather silicone joints 221A, 221B, 222A, 222B are disposed between adjacent cast glass assemblies along the outer edges of the gaps between them. The joints can have variable geometry and can vary between 5 mm and 25 mm wide to enable arrays having curved geometries.

[0128] Attaching the structural cast glass assemblies together to form wider array panels prior to installation in a building allows the rate of installation to be improved. This is particularly apparent with reference to conventional installation methods for U-channel glazing according to the prior art. Such prior art installation methods are illustrated in FIGS. 5A and 5B. These conventional techniques for on-site installation of U-channels is a slow and usually manual process, which involves handheld suckers and a sliding procedure. This involves offering a U-channel 561 into an oversized horizontal top frame 571 and subsequently lowering the U-channel into a bottom horizontal carrier 573. This process is shown in four sequential stages in FIG. 5B. The glazing is then siliconed to provide a weather seal. This technique for manual installation is incompatible with large-scale installations and those at high levels, as well as where site labour costs are high. It can also result in limited overall thermal performance caused by the installation tolerance voids (555) in the top frame, which must be maintained for glass replacement. The manual handling and installation of the U-channels, and the amount of on-site siliconing, make the system susceptible to construction site and insect contamination, inclement weather, as well as to irregular workmanship and quality issues.

[0129] In order to further benefit from the modularised assemblies and arrays of the present invention, one must move entirely away from the conventional sliding installation procedure illustrated in FIG. 5B, and the typical aluminium framing elements shown in FIG. 5A. FIG. 6 shows a thermally broken extruded aluminium profile designed to act as a horizontal carrier for a method of installation according to the invention. The carrier 680 comprises a removable front capping plate 682. The presence of this feature allows individual U-channels and cast glass units to be installed by way of being offered horizontally, rather than being slid into a top carrier and then dropped into the bottom carrier 683. Thus the need for the top carrier to comprise a large void to tolerate the upward and downward sliding movement of the glazing assembly is removed.

[0130] The installation process is illustrated in FIGS. 7A and 7B, which show a cross section and a perspective view of the carrier, respectively. Glazing array 602 is offered up horizontally, in the direction indicated by the arrow, so as to be received by a carrier, and to be held vertically between top and bottom 685, 683 elements of the carrier frame. Removable capping plates 681, 682 may then be affixed to the carrier frame, so as to hold the array 602 in place horizontally.

[0131] In the present example, pre-panelised assembly off-site is facilitated. Individual cast glass units according to the invention may be pre-fabricated, and four cast glass units are assembled together into an array module. The total size of this module is 1.7 m wide4.2 m high, including all of the vertical weathering silicone joints. This is advantageous with respect to windows and other openings being included. Such additional or inset elements may also be included, installed, sealed, and wired off-site. Wiring, for instance, may be present in building management system window contacts and power for controlling external motorised louvers.

[0132] The modularised assembly represents the first time large unitised U-channel cast glass elements have been fabricated and sealed off-site and installed in on-site modules, maintaining the quality of workmanship, in particular in the silicone, and facilitating a rate of installation that is faster than that achievable with any previous U-channel cast glass facade.

[0133] FIG. 8 depicts the exterior of a building in which multiple modular arrays 802, 802, 802 of glazing assemblies are installed vertically above one another. The central one of the three illustrated arrays 802 comprises a rectangular aperture 881. The aperture is formed by cutting through the entire depth of the modularised array. Owing to the structural strength of each assembly, and the resultant structural capacity of the array derived from this, a double- or triple-glazed, openable window unit 883 is held within the aperture, such that the weight of the unit 883 is entirely supported by the array 802.

[0134] A further example modular glazing array comprising a plurality of glazing assemblies according to the invention, similar to that shown in FIG. 4B is shown in FIGS. 9A and 9B. These drawings show a horizontal and vertical cross section view through the centre of the array, respectively.

[0135] The present example contains a glazing assembly 901 that includes an internal protective element 987 disposed in the volume between the first and second toughened glass members 915, 916. The element has the form of a polycarbonate insert that is affixed to the connector portions 905 of the assembly. This layer of impact-resistant material that is provided between the layers or volumes of insulating material 913 achieves intruder resistance in accordance with Clause H11/640. Resistance testing for conformance with this standard is defined in relation to ground-level glazing assemblies, and is carried out in accordance with BSEN356 and achieves P1A resistance class standard.