WO2015082897A1

WO2015082897A1 - Insulating glass units

Info

Publication number: WO2015082897A1
Application number: PCT/GB2014/053567
Authority: WO
Inventors: Mauro Overend; Belarmino Cordero
Original assignee: Buro Happold Limited
Priority date: 2013-12-02
Filing date: 2014-12-01
Publication date: 2015-06-11
Also published as: GB201321255D0

Abstract

Apparatus comprising an insulating glass unitand a gasket (10), the insulating glass unit comprising first and second panes of glass (1, 2) spaced apart from each other, a spacer (3) located between the first and second panes of glass (1, 2) around the outer perimeters thereof to provide a gas-tight barrier around an interior cavity of the insulating glass unit defined by the first pane of glass1, the second pane of glass (2) and the spacer (3), the spacer3being adhesively bonded to the first and second panes of glass (1, 2) to achieve composite structural action with the glass panes (1, 2), the spacer (3) and the gasket (10) being configured to engage with each other to form a seal therebetween, and the gasket (10) being for sealing with an adjacent insulating glass unit or an adjacent gasket.

Description

Insulating glass units

The present invention relates to an apparatus comprising an insulating glass unit (IGU), to a curtain wall apparatus and to methods of making each apparatus.

IGUs consist of two or more panes of glass spaced apart and sealed in a factory with dry air or gas in between. They are used primarily to reduce energy transmission into and out of a building, but they also perform to reduce internal condensation, improve thermal comfort and reduce noise transmission. The design and manufacturing of the sealing along the edge of the unit determines its durability, the extent of thermal bridging through the edge and the proportion of composite structural action between the spacer and the glass panes. To ensure durability, the sealing has to provide low moisture vapour transmission, guarantee material compatibility, have good resistance to water, temperature changes and ultraviolet radiation and be sufficiently flexible to accommodate differential thermal expansion between the glass panes and the spacer and bowing caused by pressure variations. A typical IGU uses metal spacers. Thermal bridging through the edges of the unit is a known issue associated with the use of traditional metal spacers. Moreover, the structural sealants have to be flexible to accommodate the differential thermal expansion between the glass panes and the metal spacer and, therefore, are not stiff enough to mobilise significant composite structural action from the glass panes.

Spacers made of Fibre Reinforced Polymers (FRP), which have a similar coefficient of thermal expansion to glass and low thermal conductivity compared to metals, can be adhesively bonded to the glass panes, thereby achieving composite structural action and low thermal transmittance. Such an IGU may be seen in US

2010/01 1703, US 6401428 or DE 102009057156.

Curved glass panes are appealing not only for aesthetic reasons, but also for enhanced structural efficiency. Curved glass panes are stiffer than non-curved glass panes of the same material and thickness. Thus, when using curved glass panes, it is possible to reduce the thickness of the panes. This leads to using less material and having lighter panes. Cold bending of glass is where an initially flat glass pane is bent into a curved shape at ambient temperature. This is a comparatively inexpensive alternative to traditional sag bending processes wherein the glass is heated beyond its softening temperature. WO 2013/072612 discloses a method of cold-bending an insulating glass unit.

Unitised curtain walls consist of cladding units where panel and frame are pre-assembled in a factory and then easily transported and fitted to the building. The units normally span from floor to floor hanging from pre-fixed brackets along the edge of the upper floor slab and being horizontally restrained by the units below. Unitised curtain walls are typically the facade system of choice for high rise buildings. Given the brittleness of glass and the generally large surface of these facades, glass units are designed to be easily replaced individually.

The joints between units need to accommodate in-plane differential movement between units while providing weather tightness. Typically the joints between adjacent units are sealed during construction of the curtain wall by on-site application of wet sealants to seal the gap between units. This requires external access to the curtain wall/building during construction which reduces the speed of installation. Further, wet sealants may not provide a consistently high-quality seal as their application relies upon the standard of on-site work and so may vary. Further, wet sealants may not sufficiently accommodate larger in-plane differential movements between units.

The frames used in conventional unitised curtain wall systems are inherently inefficient, both thermally and structurally. They are generally made of metal alloys with high thermal conductivities, thereby leading to substantial thermal transmission at joints. The thermal inefficiency has only recently come to the fore as the thermal performance of glass units has steadily increased, such that the thermal performance of contemporary curtain walls is governed by the edge-of-glazing and framing regions. Moreover, the frames are structurally inefficient and, therefore, larger than necessary. This leads to space planning problems and aesthetic weaknesses as the frames protrude into the buildings occupying valuable space and causing visual disruption.

The present invention provides an apparatus comprising an IGU and a gasket, the IGU comprising first and second panes of glass spaced apart from each other, a spacer located between the first and second panes of glass around the outer perimeters thereof to provide a gas-tight barrier around an interior cavity of the IGU defined by the first pane of glass, the second pane of glass and the spacer, the spacer being adhesively bonded to the first and second panes of glass to achieve composite structural action with the glass panes, the spacer and the gasket being configured to engage with each other to form a seal therebetween, and the gasket being for sealing with an adjacent IGU or an adjacent gasket.

Thus, unlike conventional units, the present invention need not have an external or additional frame. Rather the spacer effectively forms at least part of an integral frame of the IGU, the integral frame being formed by the spacer and the glass panels being bonded so as to achieve composite structural action. This increases the structural integrity of the IGU, and removes the need for any additional/external frame work.

Further, with such an arrangement, the gaskets engage directly with the IGU, and not with any external/protruding frame connected to the IGU.

The apparatus may comprise only one gasket, or a plurality of separate gaskets. When only one gasket is used, the gasket may be configured to engage the spacer along substantially the entirety of an edge of the IGU, and preferably around substantially the entirety of the perimeter of the IGU.

With apparatus of the preferred embodiments of the present invention, on-site application of wet sealants to seal the gap between IGUs can be avoided. This can be achieved by the use of a preformed gasket which can be engaged with an IGU to form a seal therewith. As a result of avoiding the use of wet sealants, external access to the IGU/building is not required during construction, higher quality control and speed of installation are achieved and larger in-plane differential movement between units can be accommodated.

Further, the apparatus allows for the gasket to be detached from and reattached to the IGU on site. This eases replacement of IGUs, and of the seals between adjacent IGUs (which may be provided by the gaskets). Due to the gasket and spacer arrangement, the IGUs of the present invention can be easily replaced individually without having to dismount other adjacent IGUs.

The IGU and the gasket may be initially provided separately and then assembled together to form the apparatus. In preferred embodiments, the apparatus is provided with the gasket fixed to the IGU. The apparatus may comprise the gasket in engagement with the spacer to form the seal. On site, another IGU may be brought into engagement with the gasket, to form a seal therewith. Thus a sealed joint is formed between the apparatus and the adjacent IGU. This can be achieved without the use of wet sealants, and achieving the other benefits mentioned above.

The IGU may further comprise an integrated bracket mounted to the IGU for mounting the IGU to a building or structure, preferably via pre-fixed brackets along the edge of floor slabs of a building. The integrated bracket may comprise a first portion which is fixed to the IGU and a second portion for being connected to a building or structure. The first portion may extend generally parallel to the IGU and the second portion may extend outward of the IGU approximately perpendicularly to the first portion and to the general plane of the IGU. The first and/or second portion(s) may be hollow. The integrated bracket may not extend beyond the outer edge of the IGU. The integrated bracket, the spacer and/or one or both of the panes of glass may provide the IGU with a flush outer edge.

Thus, unlike conventional units, the integrated bracket is not connected to an external/protruding frame. Rather the integrated bracket effectively forms part of an integral frame of the IGU, the integral frame being formed by the integrated bracket, the spacer and the glass panels all being bonded so as to achieve composite structural action. This further increases the stiffness of the IGU, and further removes the need for any additional/external frame work. The integrated bracket may be attached to the IGU using a structural adhesive.

The integrated bracket may be fixed to the exterior surface of one of the glass panes, preferably the interior glass pane. The integrated bracket may be fixed to the glass pane by using a structural adhesive and/or by mechanical fasteners, e.g. bolts.

Alternatively, the integrated bracket may be connected to the spacer.

In this case, further to using a structural adhesive, the integrated bracket may be mechanically interlocked to the open groove of the spacer. Preferably, it is the first portion of the bracket which is connected to the open groove of the spacer.

Alternatively, the first portion of the integrated bracket may be positioned within a secondary groove of the spacer. The secondary groove may be situated between the open groove nearest one pane of glass and that pane of glass. In this case, further to using a structural adhesive, the integrated bracket may be

mechanically interlocked to the secondary groove. The secondary groove may not be configured to receive the gasket, for example the width of the secondary groove may not be large enough to accept the gasket. A structural adhesive may also be used to fix the first portion relative to the secondary groove. The secondary groove may only be present in the region of the integrated bracket.

Alternatively, the integrated bracket may be mechanically interlocked within one of the panes of glass. Further, a structural adhesive and/or mechanical fasteners, e.g. bolts, may be used to fix the integrated bracket within the pane of glass.

Alternatively, the integrated bracket may be mechanically interlocked between the spacer and one of the panes of glass. The first portion of the integrated bracket may be positioned between the pane of glass and/or the spacer. In such a case, the first portion of the integrated bracket, located between the pane of glass and the spacer, may substantially replace the adhesive layer of the IGU in the region of the integrated bracket. The first portion may have thickness less than or equal to the thickness of the adhesive layer. Such an arrangement allows the spacer and pane of glass to have the same shape in areas where a bracket is present compared to areas where no bracket is present. A structural adhesive may also be used to fix the first portion relative to the IGU.

In the cases other than when the bracket is fixed to the glass pane, it may be necessary to provide a gap at/near the edge of the IGU for receiving the integrated bracket and to allow the integrated bracket to project outward from the IGU. In order to provide this gap, the IGU may be configured such that the outer edge of the first pane of glass extends beyond the outer edge of the second pane of glass, in a direction perpendicular to the outer edges of the panes of glass, by a distance (D) and the spacer provides a flush finish with the outer edge of the first pane of glass. The gap may then be provided adjacent to the outer edge of the second pane of glass. The integrated bracket extends outward of the IGU through the gap. The integrated bracket preferably has a thickness substantially equal to the distance (D). Alternatively, the integrated bracket may have thickness smaller than distance (D), with the difference in thickness allowing for a small gap between the bracket and the outer edge of the second pane of glass in order to allow for differences in thermal expansion between the bracket and the IGU. Sealant may be placed between the bracket and the spacer and/or second pane of glass.

In a region of the outer edge of the second pane of glass adjacent to the bracket, in the direction of the outer edge of the IGU, the spacer may comprise a filler portion. This filler portion may occupy the gap at the outer edge of the second pane of glass. The filler portion may have a thickness, in a direction perpendicular to the direction of the outer edge, corresponding to the distance (D). Alternatively, the filler portion may have a thickness smaller than distance (D), with the difference in thickness allowing for a small gap between the spacer and the outer edge of the second pane of glass.

The gap along the edge of the IGU may partly be occupied by the filler portion and partly occupied by the integrated bracket.

The compressible gasket of the apparatus may be configured to seal between opposite filler portions of adjacent IGUs, when said filler portions are present.

Preferably, the compressible gasket may be configured to be fixed to the filler portion of the spacer of the IGU. Further, in the region of the integrated bracket, the compressible gasket may be configured to be adjacent to the bracket surface, preferably the compressible gasket is configured to be fixed to the bracket. The second projection of the compressible gasket of the apparatus may be for being compressed against a gasket engaged and sealing with the adjacent IGU, or against the bracket and/or filler portion of the adjacent IGU itself. The bracket may be mounted to the spacer in the same groove as at least part of the gasket.

The IGU may comprise a plurality of integrated brackets. Preferably the integrated brackets may be mounted to the edges of the IGU. Further preferably, the integrated brackets may be mounted close to or at corners of the IGU. The brackets may be used as anchor points configured to force the IGU out of its natural plane, and hence inducing curvature. Thus, curvature, which can be beneficial both aesthetically and structurally, may be induced on site. In this case curvature is only maintained while the IGU is fixed to the building. Alternatively, the curvature can be induced in the factory in coordination with the application and curing of the adhesive between the glass panes and the spacer. The curvature achieved through this process is permanent.

Preferably, there may be one or more bracket(s) mounted to an upper portion of the IGU and one or more bracket(s) mounted to a lower portion of the IGU. The bracket(s) may be mounted to a top edge of the IGU and to a bottom edge of the

IGU. The bracket(s) may be mounted to the side edges of the IGU at a location near the top edge and the bottom edge. The brackets may be approximately 0-100 cm, preferably 0-50 cm, preferably 0-20 cm, preferably 0-10 cm, from the top/bottom edges.

There may be one or more bracket(s) mounted to an intermediate portion of the IGU. This may be advantageous to provide support to the IGU, especially if the IGU is particularly large. The intermediate portion may be between the upper and lower portions. The intermediate portion may be approximately half-way between the upper and lower edges of the IGU.

In use, this allows the IGU to be connected to an upper floor slab and a lower floor slab of the building/structure. The floor slabs may have complementary fixtures, such as additional brackets, to which the brackets may be attached.

This use and positioning of brackets is preferred due to the structural frame of the IGU being an integral part of the IGU. Conventional units are typically supported by an external frame from which the units are detachable. This external frame is typically attached to the building/structure and multiple units can be supported by the frame. Thus, for example, when one unit breaks, it is straightforward to simply remove the unit from the frame whilst keeping the frame, and the remaining units, in place.

Thus, in a conventional system, for example, the units can be hung from an upper floor slab and restrained by the unit below, requiring brackets at the top of the unit only. However, in the present invention, the frame is effectively an integral part of the unit (formed by the structural composite action of the spacer and the panes). Whilst this is advantageous in many respects, the inventors found that having an integral frame is disadvantageous in that removal of an IGU (e.g. when one is broken) necessarily also entails removal of the IGU's structural frame from the system. The inventors have found it is therefore not desirable to provide a structural interlock between adjacent IGUs of the present invention, since such a structural interlock would prohibit individual replacement (if the system relied on structural interlock between adjacent IGUs then individual IGUs would not be easily

removable). The inventors have developed the use brackets fixed to the upper and lower slabs of the building/structure, without structural interlock between the IGUs, to address this issue. In some ways this is actually less efficient than the conventional frame used, but resolves the issue of avoiding structural interlock between adjacent IGUs.

It may also be possible to provide a structural interlock between adjacent

IGUs, provided this structural interlock can be easily removed.

By "upper" and "lower" portions it should be understood that these are the upper and lower portions of the IGU when the IGU is mounted to a building in use.

The one or more brackets may substantially support the weight of the IGU. Thus, the structural support for the IGU may be provided by the bracket(s) and not by the gasket/spacer arrangement that connects adjacent IGUs, i.e. there may be no structural interlock between adjacent units; rather the gasket may only provide a seal.

This may further ease replacement of individual IGUs without having to dismount other adjacent units.

The first and second panes of glass of the IGU may be of substantially the same dimensions and may be positioned parallel to and aligned with each other. The spacer may be located about the entire perimeter of the IGU and may consist of one continuous piece or a plurality of pieces. Further, the glass panes could be monolithic or laminated. The glass panes could also be annealed, heat

strengthened, heat or chemically toughened or be any other type of glass suitable for providing the necessary strength for the IGU. The glass panes could be of any thickness as long as they provide the necessary stiffness for the IGU. The glass panes could be coated, sand-blasted, ceramic-fritted, acid-etched or have any other surface treatment. The glass panes could be rectangular or have any other polygonal shape. The glass panes could be planar or curved. The glass panes could be curved through the process of cold bending or hot bending. The material of the spacer may be fibre reinforced polymer, preferably plastic, further preferably pultruded fibre reinforced polymer/plastic. . The advantageous properties of the fibre reinforced polymer are generally as follows: having enough shear strength to enable significant composite action between the spacer and the glass panes; having a lower thermal conductivity coefficient compared to that of metals, which are typically used as frames/spacers, to limit thermal bridging; and having a similar coefficient of thermal expansion to that of glass to reduce differential thermal expansion with the glass panes. For example, such properties could be having shear strength over 3 MPa in the direction parallel to the edge of the IGU; having a low thermal conductivity in the direction perpendicular to the surfaces of the panes of glass, for example of 0.4W/mK or less, to limit thermal bridging; having a similar coefficient of thermal expansion in the direction parallel to the edge of the IGU (e.g. approximately 8-9x10^"6/K) to reduce differential thermal expansion with the glass panes; having similar dimensional stability against changes in humidity to glass to reduce differential shrinkage or swelling with the glass panes; having a range of working temperatures of at least from about -20°C to about 80°C; and being durable in exposed environments, e.g. when exposed to moisture, UV radiation, salts, cleaning agents, etc.

Thus, using a fibre reinforced polymer spacer reduces the thermal conductivity of the IGU, in comparison to the frames of conventional unitised curtain wall systems.

The spacer may be adhesively bonded to the first and second panes of glass by a first adhesive layer and a second adhesive layer respectively. In such a case, there may be provided a first seal for the adhesive layer, located at the edge of the IGU between the first pane of glass and the spacer, and a second seal for the adhesive layer, located at the edge of the IGU between the second pane of glass and the spacer, to protect the adhesive layers from moisture, salts, cleaning agents, etc. Each such seal may extend longitudinally and parallel to the edge of the IGU, preferably adjacent to the respective adhesive layer. Surface treatment could also be applied on the glass panes to protect the adhesives from UV radiation and/or for aesthetic reasons.

The spacer may be adhesively bonded using a structural adhesive.

The adhesive bond may be sufficiently stiff to mobilise composite structural action between the glass panes and the spacer but may be sufficiently flexible to accommodate differential thermal expansion and pressure variation bowing. The adhesive bond may have a thickness sufficient to accommodate out-of-plane manufacturing tolerances of the glass panes and the spacer, to allow easy application and to achieve suitable stiffness and flexibility for the connection. For example, the thickness may be 1 to 5mm, and preferably 2 to 3 mm.

The adhesives used may be silicones, epoxies, acrylics or any other adhesives with the appropriate properties. These properties should be sufficient to achieve composite structural action between the spacer and the glass panes. These properties are generally having sufficient shear strength to enable significant composite action between the spacer and the glass panes. For example, having shear strength in the range of 3-10 MPa; having high dimensional stability against changes in humidity to reduce differential shrinkage or swelling with the glass panes and the spacer; having a range of working temperatures of at least from about -20°C to about 80°C; being durable in exposed environments, e.g. when exposed to moisture, UV radiation, salts, cleaning agents, etc; displaying limited creep in long term loading, preferably providing visible manifestations of plastic deformation before failure; and being able to be applied through processes that allow an easy execution and reliable quality control, for example by gap filling or tape application processes that allows easy execution and reliable quality control.

The spacer may be configured to support one or more intermediate partitions. The presence of intermediate partitions can add functionality to the IGU such as improving the thermal performance or offering additional aesthetic alternatives. The partitions could be made of glass or other materials. The presence of intermediate partitions may create additional interior cavities which can improve the thermal performance of the IGU. The intermediate partitions may be transparent, translucent or opaque and may have any surface treatment.

The gas-tight barrier around the interior cavity of the IGU may be provided by the spacer having a low permeability layer that may engage the respective panes of glass in a sealing manner. The low permeability layer may comprise a low permeability material, such as a metal foil. The low permeability layer may engage the respective panes of glass in a sealing manner and extend therebetween inwardly of the spacer, i.e. on the face thereof adjacent to the interior cavity. The low permeability layer may have low water and vapour permeability.

Additionally or alternatively, the gas-tight barrier around the interior cavity of the IGU may be provided by at least one gas-tight spacer bar, preferably containing desiccant, the gas-tight spacer bar being sealed (e.g. by a low permeability sealant) to the respective panes of glass, and intermediate partitions if provided, for example to the first and second panes of glass, to one of the first and second panes of glass and an intermediate partition (if provided), or to two intermediate partitions (if provided). An advantage of using such a spacer bar is that the first and second glass panes could be assembled together first by using the spacer bar to form the sealed interior cavity and then by adhering the spacer to the glass panes. Such a two-stage process may therefore make use of an existing IGU supply chain where IGUs comprising only glass panes and spacer bars (i.e. not comprising a spacer adhesively bonded to the glass panes to achieve composite structural action) are manufactured.

The spacer may also comprise desiccant facing the interior cavity of the IGU. Such desiccant removes any residual moisture from within the interior cavity.

The interior cavity of the IGU may contain a gas, which may be dry air. The IGU may contain other inorganic or organic matter in gas, liquid or solid state to provide additional functionality.

The spacer may not extend beyond the perimeter edges of the first and/or second panes of glass, and preferably the spacer may provide a flush finish with the outer edges of the first and second panes of glass. Thus, effectively the structural frame of the IGU may be located between the first and second panes of glass only, and may not protrude beyond the perimeter edges of the first and second panes of glass.

The spacer may not extend beyond the perimeter edges of the first (external, when in use) pane of glass.

The edge of the IGU is the surface which runs around the perimeter of the

IGU.

In certain embodiments, the spacer comprises an open groove along an outer edge of the spacer, and the gasket comprises a first projection configured to at least partly overlap with and engage in the open groove of the IGU. The outer edge of the spacer is the edge of the spacer remote from the interior cavity of the IGU.

The first projection may be configured to be fixed in the open groove of the spacer of the IGU to restrict relative movement in the overlapping direction of the gasket and the IGU. The first projection may be fixed by any suitable means, such as a lip and groove arrangement. The lip and groove may be arranged to interlock to restrict relative movement in the overlapping direction, for example by interlocking in a direction substantially perpendicular to the overlapping direction. The lip may belong to the spacer and the groove to the gasket or vice versa.

Alternatively, the first projection may be configured to allow relative movement in the overlapping direction of the gasket and the IGU.

The gasket may comprise a second projection configured to overlap with and engage in an open groove of the adjacent IGU. Such a second projection may be configured to be fixed in the groove of the adjacent IGU, for example having a lip and groove arrangement as described above in relation to the first projection. In preferred embodiments, however, the second projection is configured to allow relative movement between the gasket and the adjacent IGU.

The first projection and/or second projection of the gasket may be configured to mate with a respective open groove by a friction fit. The first and/or second projection may be hollow and may be formed from a resilient material, such as a suitable polymer, e.g. an elastomer such as EPDM rubber, to allow the gasket to be deformed by the open groove when it overlaps with the open groove in order to form the friction fit. The friction fit can provide a good sealing capability.

The spacer may comprise more than one open groove, which may be parallel to one another and may have different sizes or have substantially identical dimensions to one another. The spacer may comprise only two open grooves.

The gasket may comprise a first gasket body and a second gasket body, spaced apart from each other in a direction in which the first and second panes of glass are spaced.

The gasket may have a gasket cavity at least partly defined by the first and second gasket bodies. The gasket cavity may also be defined by a spacer belonging to the IGU of the apparatus, and/or by the spacer of the adjacent IGU. The gasket is configured such that, when the gasket is used to seal between the apparatus and an adjacent IGU or an adjacent gasket, a gasket cavity is formed between the first and second gasket bodies. The gasket cavity may be at least defined by the first and second gasket bodies

The gasket may also comprise a bridging portion connecting the two gasket bodies. The bridging portion may be configured to be in contact with the edge of the IGU when the gasket is engaged with the IGU. Such a configuration can provide greater structural integrity to the sealed joint formed between two adjacent IGUs. Further, the bridging portion may be off-centred with respect to the gasket bodies, such that the first projection is shorter in length than the second projection.

The gasket is configured such that, when the gasket seals the joint between the apparatus and an adjacent IGU, the gasket cavity is formed between the first and second gasket bodies, the bridging portion, and, on the opposite side of the cavity from the bridging portion, the spacer of the adjacent IGU.

The gasket cavity may be in gas communication with the ambient air such that the cavity is pressure equalised with respect to ambient. The ambient air may be air external of the building or air internal of the building. The ambient air is typically air external to the building, which ensures that the cavity ensures good weather protection. This communication may be provided by at least one small hole extending through the gasket, for example through the first and/or second gasket body(s).

The gasket cavity may also be arranged to permit water to drain under the effect of gravity. The cavity may be suitable for draining water from within the cavity to outside of the cavity.

In certain embodiments, the second gasket body comprises a first projection configured to overlap with and engage in a second open groove of the spacer of the insulating glass unit of the apparatus, and a second projection configured to overlap with and engage in a second open groove of the adjacent IGU.

In certain embodiments, the gasket of the apparatus comprises a second projection configured to be compressed against a gasket engaged and sealing with the adjacent IGU or against the adjacent IGU. The gasket of the apparatus may comprise a compressible gasket, and, when the first and second gasket bodies are present, the first and/or second gasket body(s) may comprise a compressible gasket. The compressible gasket of the apparatus is compressible so as to be able to seal the joint between the IGU and an adjacent IGU. Preferably, it is compressible in the overlapping direction. If a gasket engaged and sealing with the adjacent IGU is provided, this may be substantially identical to the gasket of the apparatus. The gasket engaged and sealing with the adjacent IGU and the gasket of the apparatus may have mirror symmetry with respect to one another (i.e. the cross-sections of the gaskets may be mirror images of each other).

The first projection of the compressible gasket of the apparatus may overlap with the open groove of the spacer. The second projection of the compressible gasket may be for being compressed against a gasket engaged and sealing with the adjacent IGU, against the spacer of the adjacent IGU, against a glass pane of an adjacent IGU or against a bracket of the adjacent IGU.

The compressible gasket of the apparatus may be a kissing gasket (i.e. a gasket configured to engage with a gasket engaged and sealing with an adjacent IGU), or a flipper gasket (i.e. a gasket configured to engage with an adjacent IGU).

The IGU may be configured to be oriented such that the IGU comprises a first edge having a length with a horizontal component and a second edge having a length with a vertical component. The first and second edges may be adjacent to one another. Further, the first edge may be near horizontal or horizontal and the second edge may be near vertical or vertical. The IGU may be rectangular or square.

In one embodiment, when the gasket is configured to seal with a generally upwardly facing first edge of the IGU, the gasket comprises a cover portion, the width of the cover portion substantially corresponding to the width of the generally upwardly facing first edge. The width of the first edge is defined as the distance between the interior and exterior faces of the first and second panes of glass. Such a cover portion can prevent water within the gasket cavity from corroding the adhesive and entering the IGU. The cover portion may interconnect the first and second gasket bodies. The cover portion may extend through the hollow first and second gasket portions.

The upper surface of the cover portion may preferably be inclined, with respect to the horizontal, across the width of the first edge of the IGU. This may be achieved by the first edge of the IGU being non-inclined (i.e. horizontal in a width direction) and the thickness of the cover portion decreasing across the width of the first edge. In some embodiments, the cover portion may comprise the bridging portion. The gasket may also comprise one or more drainage slots through the first and/or second gasket bodies to allow water to flow out from the cavity portion. Such a gasket helps to reduce the problem of water ponding within the gasket cavity.

The gasket may be configured such that, when the gasket is engaged with a first edge, the first edge being lower than and adjacent to a second edge of the IGU, the gasket cavity is open to a gasket cavity of a second gasket engaged with the second edge of the IGU, such that the gasket cavity of the gasket may be in communication with the gasket cavity of the second gasket.

The gasket may be configured such that, when the gasket is engaged with the first edge of the IGU, it projects beyond the first edge of the IGU in the direction of the first edge, so that it may also be engaged with an edge of another IGU adjacent to the IGU. In some embodiments this gasket may be configured to be mated to three or more adjacent IGUs. The gasket may be up to around 12m long.

The gasket may be configured such that it has a length approximately equal to the length of the edge of the IGU to which is configured to engage. Such an arrangement would allow all of the edges of the IGU to be engaged with a respective gasket in the factory, which could ease on-site installation.

The invention also provides a curtain wall apparatus comprising the previously described apparatus and the adjacent IGU, wherein the gasket seals a joint between the IGU and the adjacent IGU.

The invention further provides a method comprising attaching a gasket to a spacer of a first IGU, the spacer being adhesively bonded to first and second panes of glass of the first IGU to achieve composite structural action with the glass panes.

In one embodiment, the gasket is fixedly attached to the IGU so as to restrict relative movement in an overlapping direction between the gasket and the first IGU. In another embodiment, the gasket is attached to the first IGU so as to allow for relative movement in an overlapping direction between the gasket and the first IGU.

The method may also include the step of attaching the gasket to a spacer of a second IGU, the spacer being adhesively bonded to first and second panes of glass of the second IGU to achieve composite structural action with the glass panes.

The method may also include the step of compressing the gasket against a gasket engaged and sealing with a second IGU, one of the panes of glass of a second IGU, the bracket of a second IGU, or the spacer of a second IGU, the spacer being adhesively bonded to first and second panes of glass of the second insulating glass unit to achieve composite structural action with the glass panes.

The method may also include the step of attaching one or more integrated brackets to the IGU. The brackets may be attached in any arrangement previously mentioned. This step may comprise mechanically interlocking the integrated bracket(s) with the IGU, and may also comprise adhesively bonding the integrated bracket(s) to the IGU. This may be performed prior to attaching the gasket to spacer(s) of the first and/or second IGUs.

The method may further comprise attaching the one or more integrated brackets to a building/structure.

At least one integrated bracket may be attached to an upper portion of the

IGU and at least one integrated bracket may be attached to a lower portion of the IGU, and the integrated brackets may be attached to respective upper and lower fixtures on the building/structure. The fixtures may be complimentary brackets attached to the building/structure. The integrated brackets may be fixed to upper and lower floor slabs of the building/structure.

One or more bracket(s) may be attached to an intermediate portion of the IGU. This may be advantageous to provide support to the IGU, especially if the IGU is particularly large. The intermediate portion may be between the upper and lower portions. The intermediate portion may be approximately half-way between the upper and lower edges of the IGU.

Objects of at least the embodiments of this invention are: to provide a multifunctional edge design for high performance IGUs which allows them to be brought together to construct a frameless unitised curtain wall with the following benefits against conventional unitised curtain walls: a reduction of thermal transmission at joints and, therefore, reduction of operational energy and C0₂ emissions; improved structural efficiency and, therefore, material savings and reduction of embodied energy; reduction in structural depth and, therefore, increase of the available internal net floor area; and a flush glazed appearance both to the inside and the outside which represents a substantial refinement in the aesthetics of unitised curtain walls.

Further to these benefits, the high performance IGUs may be designed so that they can be cold-bent easily to achieve a curved frameless unitised curtain wall, which provides a further refinement in the aesthetics of unitised curtain walls and enhanced structural efficiency.

Certain preferred embodiments will now be described by way of example only and with reference to the accompanying drawings, in which

FIGs. 1 , 2 and 4 show horizontal cross sectional views of the vertical edges of two IGUs and the joint between them according to embodiments of the present invention;

FIG. 3 shows a vertical cross sectional view of the horizontal edges of two IGUs and the joint between them according to another embodiment of the present invention; and

FIGs. 5A to 8D show cross sectional views of the edges of two IGUs having integrated brackets and the joint between them.

In more detail, FIG. 1 shows a horizontal cross sectional view of the edge of two IGUs and the joint between them according to the present invention.

Each IGU comprises two glass panes, one external pane 1 and one internal pane 2. The external pane of glass 1 and internal pane of glass 2 are parallel to one another and spaced apart.

Each IGU comprises a spacer 3 which runs along the entirety of the perimeter of the IGUs. The spacer 3 and the two glass panes 1 , 2 together define interior cavities 6 of the IGUs.

The spacer 3 is sufficiently stiff to mobilise composite structural action with the glass panes 1 , 2 when the spacer 3 and the glass panes 1 , 2 are adhesively bonded together. The IGU includes a gas-tight barrier 4 that is positioned between each of the glass panes 1 , 2 and the spacer 3, and that could be a thin metal foil or any other low permeability material. The IGU also comprises a low permeability sealant 5 which is applied between the glass panes 1 , 2 and the gas-tight barrier 4. The function of these elements is to prevent moisture from entering the interior cavities 6.

The spacer 3 incorporates an intermediate partition 7 to create a plurality of interior cavities 6 for improved thermal performance. These intermediate partitions 7 could be made of glass or other transparent, translucent or opaque materials and could have any surface treatment.

The IGU also includes desiccant 8 positioned on the spacer 3 such that desiccant 8 faces the cavities 6 to remove any residual moisture. The cavities 6 could be filled with dry air or any other gases for improved thermal performance. The IGU may contain other inorganic or organic matter in gas, liquid or solid state to provide additional functionality.

The spacer 3 comprises two open grooves 9 facing the edge of the IGU. Further, the joint between the two IGUs is provided by an overlapping gasket 10 which overlaps with and engages in the open grooves 9 of the spacer 3.

The spacer 3 fits within the interior cavity depth to provide a flush finish both to the internal and external glass panes 1 , 2 and does not extend beyond the projection of the glass panes 1 , 2 in elevation.

An adhesive 12 is applied along all of the perimeter of the IGUs to bond the spacer 3 to the glass panes 1 , 2. First and second seal 13 is incorporated between the glass panes 1 , 2, the spacer 3, the adhesive 12 and the perimeter edge of the IGU to protect the adhesive from moisture, salts, cleaning agents, etc.

The adhesive bond is sufficiently stiff to mobilise composite structural action between the glass panes and the spacer but sufficiently flexible to accommodate differential thermal expansion and pressure variation bowing.

As is shown in FIG. 1 , the gasket 10 comprises two gasket bodies 20, 30, each gasket body 20, 30 comprising a first projection 21 , 31. The first projections are fixed in respective open grooves 9 of the IGU to restrict relative movement in the overlapping direction of the gasket and the IGU. The open grooves 9 are parallel to one another and have substantially identical dimensions to one another.

Additionally, each gasket body 20, 30 comprises a second projection 22, 32, the second projection 22, 32 overlapping with and engaging in the open groove 9 of the spacer 3 of another IGU to allow relative movement between the gasket 10 and the another IGU. The first and second gasket bodies 20, 30 are hollow and formed from a resilient material to allow the gasket 10 to be deformed by the open grooves 9 when it overlaps with the open grooves 9 in order to form a friction fit and seal.

A gasket cavity 1 1 is formed between the first 20 and second 30 gasket bodies, and the spacers 3 of the two IGUs. The gasket cavity 11 is in gas communication with the ambient air such that the cavity is pressure equalised with respect to the ambient. This communication is provided by at least one small hole extending through the gasket. The gasket cavity 1 1 is also arranged to permit water to drain. The gasket cavity 11 is suitable for draining water from within the cavity to outside of the cavity.

FIG. 2 also shows a horizontal cross sectional view of the edge of two IGUs and the joint between them according to the present invention. In this embodiment, the first gasket body 20 comprises a compressible gasket. The compressible gasket is compressible so as to be able to seal the joint between the two IGUs. The first projection 21 of the compressible gasket overlaps with the open groove of the spacer. The second projection 22 of the compressible gasket is compressed against a compressible gasket 23 engaged and sealing with the second IGU.

FIG. 3 shows a vertical cross sectional view of the edge of two IGUs and the joint between them according to the present invention. Further, in the FIG. 3 embodiment, the gasket 10 comprises a first gasket body 20 and a second gasket body 30 connected by a bridging portion 40. The first and second gasket bodies 20, 30 and the IGUs are similar to those of the FIG. 1 embodiment. The gasket cavity 1 1 is formed between the spacer 3, the first 20 and second 30 gasket bodies and the bridging portion 40.

Further, in the FIG. 3 embodiment, the gasket is configured to seal with a generally upwardly facing edge of the IGU, and the gasket 10 comprises a cover portion 41. The width (W) of the cover portion 41 substantially corresponds to the width (W) of the generally upwardly facing first edge. The cover portion 41 extends through the first and second gasket bodies 20, 30.

An upper surface 42 of the cover portion 41 is inclined, with respect to the horizontal, across the width of the first edge of the IGU. This is achieved by having a non-inclined (i.e. horizontal in a width direction) edge of the IGU and having the thickness of the cover portion 41 decrease across the width of the edge. The cover portion 41 comprises the bridging portion 40. The gasket 10 also comprises one or more drainage slots (not shown) through the first body 20 to allow water to flow out from the cavity portion.

The gasket 10 is further configured such that, when the gasket 10 is mated with a first edge of the IGU which is lower than and adjacent to a second edge of the IGU, the gasket cavity 1 1 may be open to a gasket cavity 11 of a second gasket 10 mated to the second edge of the IGU, such that the gasket cavity 1 1 of the gasket 10 may be in communication with the gasket cavity 1 1 of the second gasket 10

FIG. 4 shows a horizontal cross sectional view of the edge of two IGUs and the joint between them according to another embodiment of the invention where a conventional IGU edge design is retained with gas-tight spacer bars 15 containing desiccant 8. The gas-tight spacer bars 15 are sealed to the glass panes 1 , 2 and intermediate partition 7 to form the sealed interior cavities 6. A low permeability sealant 5 is applied between the glass panes 1 , 2 and intermediate partition 7 and the spacer bars. The spacer bars 15 are offset from the outer edges of the IGU to leave a gap in which the spacer 3 is inserted and adhesively bonded 12 to the glass panes 1 , 2. This alternative arrangement offers the possibility of splitting the assembly into two stages and makes better use of the existing IGU supply chain. A conventional IGU could be ordered and then the spacer could be incorporated in a different location.

As is shown in the embodiments of FIGs. 5A to 8D, the IGU further comprises an integrated bracket 14 mounted to the IGU for mounting the IGU to a building or structure, preferably via pre-fixed brackets along the edge of floor slabs of a building.

FIGs. 5B, 5D, 6B, 6D, 7B, 7D, 8B, and 8D show a cross-sectional view of an edge of the IGU having an integrated bracket, the cross-section being taken at a position adjacent to where the integrated bracket 14 is present. Hence, the integrated bracket 14 is shown in outline in these FIGs.

The integrated bracket 14 comprises a first portion 16 which is fixed to the

IGU and a second portion 18 for being connected to a building or structure. The first portion 16 extends generally parallel to the IGU and the second portion 18 extends outward of the IGU approximately perpendicularly to the first portion 16.

The integrated bracket 14, the spacer 3, and the exterior (and interior, in some embodiments) pane of glass 2 provide the IGU with a flush outer edge.

The IGU and gasket of the FIG. 5A and 5B embodiment are the same as those of the FIG. 1 embodiment, and the IGU and gasket of the FIG. 5C and 5D embodiment are the same as those of the FIG. 3 embodiment.

As shown in FIGs. 5A to 5D, the integrated bracket 14 is fixed to the exterior surface 19 of the interior glass pane 2. The integrated bracket 14 may be fixed to the glass pane by using a structural adhesive.

As shown in FIGs. 6A to 6D, the integrated bracket 14 is mechanically interlocked between the spacer 3 and the interior glass pane 2. The first portion 16 of the integrated bracket 14 is positioned between the interior pane of glass and the spacer. In such a case, the first portion 16 substantially replaces the adhesive layer

12 of the IGU in the region of the bracket 14. The first portion 16 has a thickness substantially equal to the thickness of the adhesive layer 12. A structural adhesive may also be used to fix the first portion 16 relative to IGU.

As shown in FIGs. 7A to 8D, the integrated bracket 14 is connected to the spacer 3. As shown in FIGs. 7 A to 7D, the integrated bracket 14 is mechanically interlocked within the spacer 3. The first portion 16 positioned within a secondary groove 9' of the spacer 3. The secondary groove 9' is situated between the open groove 9 nearest the interior pane of glass 2 and the interior pane of glass 2. A structural adhesive may also be used to fix the first portion relative 16 to the secondary groove 9'. As can be seen from FIGs. 7B and 7D, the secondary groove 9' is only present in the region of the integrated bracket 14.

As shown in FIGs. 8A to 8D, the first portion 16 of the integrated bracket 14 is mechanically interlocked to the open groove 9 of the spacer. A structural adhesive may also be used to fix the first portion relative 16 to the open groove 9. In this embodiment, the first portion 16 is hollow.

In the FIGs. 6A to 8D embodiments, a gap 60 is provided at the edge of the IGU for receiving the integrated bracket 14 and to allow the integrated bracket 14 to project outward from the IGU. In order to provide this gap 60, the IGU is configured such that the outer edge of the exterior pane of glass 1 extends beyond the outer edge of the interior pane of glass 2, in a direction perpendicular to the outer edges of the panes of glass 1 , 2, by a distance (D) and the spacer 3 provides a flush finish with the outer edge of the exterior pane of glass 1. The gap 60 is provided adjacent to the outer edge of the interior pane of glass 2. The integrated bracket 14 extends outward of the IGU through the gap 60. The integrated bracket 14 has a thickness less than the distance (D). Sealant 13 is placed between the integrated bracket 14 and the spacer 3 and/or interior pane of glass 2. The sum of the thicknesses of the sealant 13 and the integrated bracket 14 is substantially equal to the distance (D).

As can be seen in FIGs. 6B, 6D, 7B, 7D, 8B, and 8D, in a region of the outer edge of the interior pane of glass 2 adjacent to the bracket 14, in the direction of the outer edge of the IGU, the spacer 3 comprises a filler portion 17. This filler portion 17 occupies the gap 60 at the outer edge of the interior pane of glass 2. The filler portion 17 has a thickness, in a direction perpendicular to the direction of the outer edge, substantially corresponding to the distance (D). The gap 60 along the edge of the IGU is thus partly occupied by the filler portion 17 and partly occupied by the integrated bracket 14.

As can be seen in FIGs. 8A to 8D, when one of the open grooves 9 is used to mechanically interlock with the integrated bracket 14, the second gasket body 30 comprises a compressible gasket 33 which is configured to seal between opposite filler portions 17 of adjacent IGUs, when said filler portions 17 are present. The first projection 31 of the compressible gasket 33 is also configured to be fixed to the filler portion 17 of the spacer of the IGU. Further, in the region of the integrated bracket 14, the compressible gasket 33 is configured to be adjacent to the bracket surface. The second projection 32 of the compressible gasket is compressed against a gasket engaged and sealing with the adjacent IGU.

Claims

Claims:

1. Apparatus comprising an insulating glass unit and a gasket, the insulating glass unit comprising first and second panes of glass spaced apart from each other, a spacer located between the first and second panes of glass around the outer perimeters thereof to provide a gas-tight barrier around an interior cavity of the insulating glass unit defined by the first pane of glass, the second pane of glass and the spacer, the spacer being adhesively bonded to the first and second panes of glass to achieve composite structural action with the glass panes, the spacer and the gasket being configured to engage with each other to form a seal therebetween, and the gasket being for sealing with an adjacent insulating glass unit or an adjacent gasket.

2. Apparatus as claimed in claim 1 , wherein the insulating glass unit further comprises an integrated bracket mounted to the insulating glass unit for mounting the insulating glass unit to a building or structure and/or for acting as an anchor point for forcing the insulating glass unit out of its natural plane, and hence inducing curvature.

3. Apparatus as claimed in claim 2, wherein the integrated bracket is mounted to the edge of the insulating glass unit.

4. Apparatus as claimed in claim 2 or 3, wherein the insulating glass unit comprises at least two of the integrated brackets, at least one bracket being mounted to an upper portion of the insulating glass unit and at least one bracket being mounted to a lower portion of the insulating glass unit.

5. Apparatus as claimed in any preceding claim, wherein the spacer comprises fibre reinforced polymer.

6. Apparatus as claimed in any preceding claim, wherein the spacer does not extend beyond the perimeter edges of the first or second panes of glass.

7. Apparatus as claimed in any preceding claim, wherein the gasket comprises a first gasket body and a second gasket body, spaced apart from each other in a direction in which the first and second panes of glass are spaced.

8. Apparatus as claimed in claim 7, wherein the gasket defines a gasket cavity at least partially defined by the first and second gasket bodies.

9. Apparatus as claimed in claim 8, wherein the gasket cavity is in gas communication with ambient air such that the cavity is pressure equalised with respect to ambient.

10. Apparatus as claimed in claim 8 or 9, wherein the gasket cavity is arranged to permit water drainage under the effect of gravity.

1 1. Apparatus as claimed in any preceding claim, wherein the spacer comprises an open groove along an outer edge of the spacer, and the gasket comprises a first projection configured to at least partly overlap with and engage in the open groove of the insulating glass unit.

12. Apparatus as claimed in claim 11 , wherein the first projection is configured to be fixed in the open groove of the spacer of the insulating glass unit to restrict relative movement in the overlapping direction of the gasket and the insulating glass unit.

13. Apparatus as claimed in claim 11 or 12, wherein the gasket comprises a second projection configured to overlap with and engage in an open groove of the adjacent insulating glass unit.

14. Apparatus as claimed in claim 11 or 12, wherein the gasket comprises a second projection configured to be compressed against a gasket of the adjacent insulating glass unit or against an adjacent gasket engaged and sealing with the adjacent insulating glass unit.

15. Apparatus as claimed in any preceding claim, wherein the spacer comprises more than one open grooves.

16. Apparatus as claimed in any preceding claim, wherein the insulating glass unit is configured to be oriented such that the insulating glass unit comprises a first edge having a length with a horizontal component and a second edge having a length with a vertical component.

17. Apparatus as claimed in claim 16, wherein, when the gasket is configured to seal with the first edge of the insulating glass unit, the gasket comprises a cover portion, the width of the cover portion substantially corresponding to the width of the first edge, the cover portion interconnecting the first and second gasket bodies.

18. Apparatus as claimed in claim 17, wherein the upper surface of the cover portion is inclined with respect to the horizontal across the width of the first edge of insulating glass unit.

19. Apparatus as claimed in any of claims 16 to 18, when dependent on claim 8, wherein the gasket is configured such that, when the gasket is engaged with a first edge, the first edge being lower than and adjacent to a second edge of the insulating glass unit, the gasket cavity is open to a gasket cavity of a second gasket engaged with the second edge of the insulating glass unit, such that the gasket cavity of the gasket may be in communication with the gasket cavity of the second gasket.

20. Apparatus as claimed in any of claims 16 to 19, wherein the gasket is configured such that, when the gasket is engaged with the first edge of the insulating glass unit, it projects beyond the first edge of the insulating glass unit in the direction of the first edge, so that it may also be engaged to an edge of another insulating glass unit adjacent to the insulating glass unit.

21. Apparatus as claimed in any preceding claim, wherein the gas-tight barrier around the interior cavity of the insulating glass unit is provided by a gas-tight spacer bar, the gas-tight spacer bar being sealed to the respective panes of glass.

22. A curtain wall apparatus comprising:

the apparatus as claimed in any preceding claim; and

the adjacent insulating glass unit,

wherein the gasket seals a joint between the insulating glass unit and the adjacent insulating glass unit.

23. A method comprising attaching a gasket to a spacer of a first insulating glass unit, the spacer being adhesively bonded to first and second panes of glass of the first insulating glass unit to achieve composite structural action with the glass panes.

24. A method as claimed in claim 23, wherein the gasket is fixedly attached to the first insulating glass unit so as to restrict relative movement in an overlapping direction between the gasket and the first insulating glass unit.

25. A method as claimed in claim 23 or 24 further comprising the step of attaching the gasket to a spacer of a second insulating glass unit, the spacer being adhesively bonded to first and second panes of glass of the second insulating glass unit to achieve composite structural action with the glass panes.

26. A method as claimed in claim 23, 24 or 25 further comprising the step of compressing the gasket against a gasket attached to a second insulating glass unit, the spacer of a second insulating glass unit, the bracket of a second insulating glass unit or a pane of glass of a second insulating glass unit, the spacer being adhesively bonded to first and second panes of glass of the second insulating glass unit to achieve composite structural action with the glass panes.

27. A method as claimed in any of claims 23 to 26 further comprising the step of attaching one or more integrated brackets to the IGU.

28. A method as claimed in claim 27 further comprising attaching the one or more integrated brackets to a building/structure.

29. A method as claimed in claim 28 wherein at least one integrated bracket is attached to an upper portion of the IGU and at least one integrated bracket is attached to a lower portion of the IGU, and wherein the integrated brackets are attached to respective upper and lower fixtures on the building/structure.

30. An apparatus or a method substantially as herein described with reference to figures of the accompanying drawings.