U.S. patent application number 16/484601 was filed with the patent office on 2020-02-06 for glazing assembly.
This patent application is currently assigned to IAN RITCHIE ARCHITECTS LTD.. The applicant listed for this patent is IAN RITCHIE ARCHITECTS LTD.. Invention is credited to Ian RITCHIE.
Application Number | 20200040575 16/484601 |
Document ID | / |
Family ID | 58462507 |
Filed Date | 2020-02-06 |
United States Patent
Application |
20200040575 |
Kind Code |
A1 |
RITCHIE; Ian |
February 6, 2020 |
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.
Inventors: |
RITCHIE; Ian; (London,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IAN RITCHIE ARCHITECTS LTD. |
London |
|
GB |
|
|
Assignee: |
IAN RITCHIE ARCHITECTS LTD.
London
GB
|
Family ID: |
58462507 |
Appl. No.: |
16/484601 |
Filed: |
February 8, 2018 |
PCT Filed: |
February 8, 2018 |
PCT NO: |
PCT/GB2018/050356 |
371 Date: |
August 8, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E04C 1/42 20130101; E04C
2/54 20130101 |
International
Class: |
E04C 2/54 20060101
E04C002/54; E04C 1/42 20060101 E04C001/42 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 8, 2017 |
GB |
1702035.5 |
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.degree..
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
FIELD OF THE INVENTION
[0001] The present invention relates to a glazing assembly
comprising first and second toughened glass members. In particular,
the invention relates to an assembly wherein first and second
toughened glass members are joined together such that the
structural performance of the assembly is improved.
[0002] BACKGROUND TO THE INVENTION
[0003] U-channel cast glass is a low-cost cladding material which
has been available on the market for over four decades. These
U-channels comprise a strip of glass bent or moulded in a U-shape,
typically using a machine rolling process, and generally come in a
set number of profiles and widths which are broadly homogenous
across manufacturers worldwide. Widths available are generally
circa 232 mm, 262 mm and 330 mm. As a general principle, the wider
the U-channel, that is the greater the distance across the central
sheet or between the return flanges, the less vertical distance it
can span. Furthermore, wider U-channels generally require the
return flanges to be more shallow, that is extending less far in
the direction in which they project from the sides of the sheet in
proportion to the width of the sheet.
[0004] In the last decade, advances in the toughening (tempering)
process has improved and removed the need for casting metal wire
support into the channels to strengthen the span. This has also
allowed toughened U-channel glass to be installed at high levels
because it can break safely.
[0005] The dielectric (insulating) properties of glass in buildings
first surfaced as a need in the early part of the 20th century.
Examples of double facades using two layers of single glazing first
appeared in Russia in the 1920s. However, these early examples
failed to account for glass having virtually no dielectric
property, and in such arrangements, the single outer window will
quickly reach the same temperature as the outside.
[0006] At a similar time, the idea of having a sealed unit of two
skins of glass separated by air was put forward, and the first
product was manufactured in 1944 using a welded glass spacer. A
double wall with the outer wall double-glazed provides a thermally
efficient arrangement. However, cost starts rising dramatically.
This, coupled with access between the panes being limited, further
complicates the facade construction and begins to reduce the
useable floor area of the building.
[0007] Today, thermal performance of triple glazed insulated glass
units can achieve insulating properties with U Value of 0.8
W/m.sup.2K. But the cost of production, and the weight of the unit,
which typically includes 12 mm glass+16mm air+6 mm glass+16 mm
air+6 mm glass precludes much use of it. And ultimately with all
insulated glazing units (IGUs) the boundary seals fail over
time.
[0008] Historically, glass facades were used when little thermal
insulation was required and this led to the development, in the
early 1980s, of structural glazing. The system designed by Rice
Francis Ritchie for the Bioclimatic Facades at the Cite des
Sciences, La Villette, France, relies upon an innovative
articulated stainless steel ball-joint fixing through a machined
countersunk hole in the toughened float glass and separated by pure
aluminium washers. The articulation avoids bending stresses in the
glass and the fixing can carry up to 4 tonnes (40 kN). A similar
system but with much less loading capacity (approximately 0.7
tonnes: 7 kN)--is Pilkington Planar, formed of float toughened
glass panels held by fixed bolts--a "point-fixed" system to create
a structural glass "wall". The continued appeal of such a system
among architects focuses on the transparency of the assembly and a
seemingly "frameless" structure.
[0009] By contrast, cast glass U-channels require a series of
support channels connected by movement joints instead of struts or
trusses. Currently, U-channels can be installed in a variety of
ways depending on requirements, vertically or horizontally, in
single profile, wherein glazing consists of a single layer of
U-channels, or an "interlocked" double profile, wherein U-channels
are arranged in two opposing layers typically such that their
flanges are overlapping or abutting.
[0010] Additionally, current manual techniques for installing
U-channels in these arrangements, and the amount of on-site
assembly and sealing that is required, make the system susceptible
to contamination by construction site materials and insects.
[0011] Therefore a need exists for a glazing assembly utilising
glass that can provide increased structural performance, as well as
thermal performance and protection against on-site contaminants,
while being suitable for rapid, large-scale installation and to
allow aluminium-framed windows and external louvers to be
integrated into the module without the need to introduce any
additional structural support element.
SUMMARY OF THE INVENTION
[0012] In accordance with the invention there is provided 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.
[0013] The members may therefore be arranged such that the flanges
of each member are projecting towards, and opposing, the flanges of
the other member, and may be attached together by a first and a
second connector portion between the first and second flanges of
each member, respectively. In other words, the members may be
arranged such that the sheets of the members are opposing, and the
flanges of each member project inwardly towards the flanges of the
other member, and wherein the inwardly facing edge of each flange
of the first member is joined to the inward facing edge of the
opposing flange of the second member by a connector portion. In
this sense, the direction described as inward refers to the
direction pointing towards the centre or centre plane of the
assembly, or equivalently pointing from each member towards the
opposing member.
[0014] Typically, and in particular where a flat or planar glazing
facade or facade components are required, the sheet of one or both
of the first and second member is planar. The sheet of one or both
of the first and second members may be a web. The members may be
arranged such that the sheets of the first and second member are
substantially parallel to one another, as well as the flanges of
the first and second member being aligned. In some embodiments, the
sheets and flanges of the first member are substantially parallel
to the sheet and flanges of the second member, respectively, and an
edge of each of the first and second flanges of each member faces,
and is joined by a connector portion to, and an edge of a flange of
the other member. In other words, the members may be attached
together by first and second connector portions joining the first
and second flanges of the first member to the first and second
flanges of the second member, respectively. In this way, the first
and second members may be attached together by way of a connector
portion joining an edge of each flange of the first member to a
facing edge of each flange of the second member.
[0015] Typically, each member is formed as a U-channel, or U-shaped
channel, or a girder, beam, strut, or other type of elongate member
having a cross section perpendicular to the elongate access that is
substantially U-shaped. U-profile glass, or U-channel glass, is
widely used in architectural applications. These U-shaped sections
generally comprise a central sheet with flanges projecting upwards,
or orthogonally, along either edge of the sheet, with each flange
terminating at an edge face. These edge faces may have a normal
vector parallel to the direction substantially perpendicular to the
sheet, or to the direction in which the first and second flanges
project from the opposite ends of the sheet. The U-channel members
of the present arrangement may therefore be held together in an
opposing arrangement such that the ends, or edge faces of the first
and second flanges of the first member oppose the ends or edge
faces of the first and second flanges of the second member. Thus a
toe-to-toe, or edge-to-edge arrangement may be provided, wherein
the edge faces of the first and second flanges of the first member
are opposing, or are aligned with, the edge faces of the first and
second flanges of the second member, that is the edges of the
flanges of the first member face the edges of the flanges of the
second member.
[0016] Typically, therefore, the flanges of each member do not
overlap the flanges of the other member. The U-channels are
arranged with their flanges edge-to-edge such that the depth of the
glazing assembly includes the total depth of each pair of flanges,
meaning that the assembly depth includes twice the depth of a
single flange if the flanges are the same depth for each of the
first and second member. The term depth is used here to refer to
the extent or linear size of the assembly in the direction
perpendicular to the sheets. Typically, the volume occupied by, or
defined by, each of a single U-channel and the glazing assembly has
dimensions such that the depth as defined in this way is the
smallest dimension.
[0017] The members are arranged such that the flanges of each
member project, in the direction of the depth of the U-channel and
assembly, towards the flanges of the other member, and each flange
of the first member is bonded to a flange of the second member by a
connector portion.
[0018] The assembly is typically installed as glazing on a
building, with the assembly oriented such that the outer face of
the sheet of one member faces outwards from the building, and the
outer face of the sheet of the other member faces towards of the
interior of the building. The outer face of the sheet of each
member in the assembly is that which faces away from the other
member and away from the interior of the assembly. Thus the
assembly can function as a panel in a glazing facade. The issues
inherent to working with U-channel cast glass, for example, have
been addressed by the present arrangement by a way of unitising and
modularising the building envelope. This has been made possible due
to the strength which has been found to be achieved by structurally
bonding the U-channels together with a purpose made polyamide
thermal break. This will allow, subject to wind load criteria,
greatly increased structural spans. Bonding the two U-channels
together in a flange-to-flange arrangement provides increased
structural strength compared with prior art geometric arrangements,
such as those wherein two U-channels are interlocked such that one
of the flanges on each member abuts the sheet of another
member.
[0019] The reason for this improvement is the inherently stronger
structure achieved by attaching the flanges in an edge-to-edge
arrangement. This provides the assembly with increased depth, and a
more square cross section, than the interlocked arrangement formed
from U-channels of the same or equivalent dimensions. This
increases the resistance to force applied to the assembly, for
example wind load, owing to there being more material to resist in
the depth axis of the assembly. This advantageous effect may also
be understood in terms of the additional squareness or depth
provided by arranging two U-channels of given dimensions in a
toe-to-toe arrangement rather than an interlocking arrangement
approximately doubling the depth of the assembly while effectively
halving the thickness of each flange (since the flanges are in
single thickness and non-overlapping). This results in a greater
section modulus, which is related to the strength or load capacity
of the assembly, and its resistance to bending or failure.
[0020] This effect, of increasing the structural capacity of a
hollow rectangular tube formed by an attached pair of glass
U-channels is a key advantage provided by the assembly. This has
previously not been achievable with interlocked arrangements, owing
to the depth of the overall assembly being limited ultimately by
the depth of the flanges, that is their extent in the direction in
which they project from the sheet. The process of casting glass
U-channels and forming the flanges and flange edges inherently
imposes an upper limit upon U-channel depth, that is flange
extent.
[0021] Constructing the assembly from members that are formed from,
or comprise, toughened or tempered glass contributes to the
mechanical strength of the assembly and therefore to the
advantageous structural capability it provides. Such glass may be
produced by way of applying thermal or chemical treatments to the
cast glass U-channels, for example, so as to put the outer surfaces
of the members into compression and the centre or interior of the
member, that is the glass between those outer surfaces, into
tension.
[0022] Typically, the glass members are toughened by way of a heat
treatment process wherein each cast glass member is caused to
travel through a tempering oven. Thus the glass is typically heated
to a temperature in excess of 600.degree. C. Preferably this
comprises raising the glass temperature to 620.degree. C. The glass
then typically undergoes a quenching procedure, which comprises
cooling the glass under high pressure, or pressure in excess of
atmospheric pressure. This typically comprises directing jets or
streams of high-pressure air at the member from an array of nozzles
so as to blast the surface of the glass. This causes the outer
surfaces of the glass to cool at a faster rate than the centre. As
the centre of the glass cools, it pulls back from the outer
surfaces. As a result, the centre remains in tension, and the outer
surfaces remain in compression, which affords tempered glass its
increased strength.
[0023] In some embodiments the glass of the members is toughened by
way of chemical tempering, wherein chemicals are caused to exchange
ions on the surface of the glass in order to create compression,
thereby achieving increased strength. In embodiments comprising
cast glass members, such chemical toughening processes are
typically not used, but rather toughening is performed by way of
heat treatment.
[0024] A toughened glass member having these properties typically
possesses far greater mechanical strength than an equivalent member
formed from annealed or non-toughened glass. For example, while
annealed glass may break when subjected to a pressure of around
6,000 pounds per square inch (psi) or around 41 MPa, toughened
glass typically breaks at an applied pressure of approximately
24,000 psi or 165 MPa. The toughened glass members of the assembly
may be selected, or the toughening treatment applied to them, may
be based at least in part upon their being able to withstand
pressure up to such a maximum value.
[0025] The increased strength, load capacity, and resistance to
movement provided by the assembly allow it to be used structurally.
For U-channels of given dimensions, the possible vertical span of
the assembly, when arranged so that the tube formed by the attached
U-channels is aligned vertically, is vastly increased with respect
to prior art geometric arrangements.
[0026] In typical embodiments, one or each of the first and second
members of the assembly comprise or are formed from toughened cast
glass. It is also envisaged, however, that the members may comprise
or be formed from other types of toughened glass. Types of
toughened glass that may be used to form the members additionally
include: crown glass, cylinder glass, cast plate glass, polished
plate glass, rolled plate glass, drawn sheet glass, and float
glass.
[0027] The first and second flanges of the first member being
substantially coplanar with the first and second flanges of the
second member, respectively, typically means that each flange is
aligned substantially in the same plane as the opposing flange to
which it is joined. Thus each joined pair of flanges forms a side
of the tubular assembly, with the substantially rectangular tube
having a depth greater than or equal to the total depth of both
members, the depth of each member being defined by the depth of the
flanges. The substantially coplanar arrangement includes the
possibility that there may be a slight offset or lateral
misalignment between joined flanges such that they are not
perfectly coplanar. In such arrangements, the edge faces of
opposing, joined flanges might not be perfectly aligned.
Nevertheless, such arrangements, when maintaining the toe-to-toe
arrangement may still be considered as having substantially
coplanar joined flanges and would achieve the strengthening effect
of joining the opposing flanges end-to-end so as to form a tubular
structure of increased depth. This tubular structure, in
embodiments wherein the flanges are differently aligned owing to an
offset between the first and second members or a difference in size
between the flange to flange widths of the first and second
members, would have a discontinuity in one or both sides of the
tubular structure, at the region where the flanges are joined to
one another.
[0028] In typical embodiments, the first and second connector
portions comprise first and second connectors respectively. Thus a
first connector may be disposed at the interface between the first
flange of the first member and the first flange of the second
member, and a separate, second connector may be disposed at the
interface between the second flange of the first member and the
second flange of the second member.
[0029] In some embodiments, the first and second connector portions
comprise first and second portions of a first connector. The first
connector portion may be linked or connected to the second
connector portion by a linking portion, two linking portions, or a
plurality of linking portions. The first and second connector
portions may thus be formed from a unitary piece or extrusion, or
may be formed from two or more separate pieces that are bonded or
adhered together. A linking portion may join the first and second
connector portions between respective ends of the first and second
connector portions. A linking portion may be disposed across an end
or opening of a tubular structure formed by the assembly, or across
the interior volume of the assembly.
[0030] Typically, the connector portion disposed between each
joined pair of flanges comprises a polymer. Preferably, the
material from which the connector portions are formed comprises a
polyamide, and more preferably each connector portion is formed as
a polyamide extrusion. The polymer may typically comprise in epoxy,
vinylester, or polyester thermosetting plastic. More preferably, a
connector portion may comprise a fibre-reinforced polymer. The
fibres in such embodiments may comprise glass, carbon, basalt or
synthetic fibres.
[0031] Preferably, the material from which each or both of the
first and second connector portions is formed has any one or more
of the following mechanical properties: tensile strength in the
range 60-240 Nmm.sup.-2, more preferably at least 110 Nmm.sup.-2;
modulus of elasticity in tension of at least 6,000 Nmm.sup.-2;
flexural modulus in the range 1.3-19.0 GPa, and more preferably in
the range 4-8 GPa; flexural strength in the range 80-260 Nmm.sup.-2
and more preferably 110-210 Nmm.sup.-1; and tensile strain at break
of at least 2.5%. The material is typically a polymer, or
preferably a polyamide, or a thermoplastic, and is may be selected
based upon the material having such mechanical properties,
typically for the dry material as moulded and at 23.+-.2.degree.
C., according to testing standard ISO 527. For example, TECATHERM
66 GF, designation Thermoplastic ISO 1874-PA 66-HI,EC2L, GF25, or
polyamide 66 with 25.0.+-.2.5% by weight glass fibres may be
selected for the connecting portions, in accordance with these
requirements.
[0032] Preferably the material of the connector portions is
selected so as to avoid the connector portions displaying
rubber-like elasticity. For this reason it is preferable to select
a polymer that is, or is substantially, inelastic , that is a
non-elastomer. The result is that the connector portions are
capable of no or negligible segmental motion, at the relevant
temperature ranges of use. The preferable advantageous stiffness of
the connector material may be achieved by selecting a connector
portion material having a Young's modulus in the range 1,700-2,000
MPa. More preferably the connector portions are formed from a
material having a Young's modulus of 1,850 MPa. Such a selection of
material can result in a substantially non-deformable connector
portion and thereby in the prevention, reduction or elimination of
deformation of the connector portions when the assembly is
subjected to wind loads and vertical loads.
[0033] As indicated above, two U-channel members according to the
present disclosure may advantageously behave as a composite
profile. In combination with this, the connector portions, which
are typically formed from polyamide extrusion, adhered with an
adhesive such as structural silicone, may provide an improved area
moment of inertia in comparison with a weak composite effect which
would be achieved with less stiff, and more deformable and elastic
connector portions.
[0034] The area moment of inertia of two U-channel members
connected by a such an alternative, less stiff connector such as
one formed from rubber material would be approximately in the range
140-145 cm.sup.4. The theoretical area moment of inertia of a
perfectly stiff assembly would be 2,873 cm.sup.4.
[0035] The presence of a connector portion disposed between each
pair of opposing flanges serves to provide impact protection for
the assembly. That is, any impact or sudden acceleration or
movement experienced by a member with respect to the opposing
member cannot result in the opposing members, and in particular the
flanges thereof, impacting one another, since each connector
portion lies between the opposing flange edges which would
otherwise be liable to impact one another in absence of the
connector portions should the members be moved towards one another.
Conversely, interlocked arrangements of the prior art are afforded
no such impact protection, since the glass members typically
directly contact one another, or might be separated from one
another by adhesive which provides little or no impact protection.
Thus a further advantage provided by the present arrangement over
the prior art can be seen.
[0036] In some embodiments, 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. In other words, the connector portions typically join
the members together along the edges of the flanges. Each channel
may be shaped or adapted to receive an edge, or an end or edge face
of a flange. Each channel may be further adapted to grip an edge
portion of a flange, for example a channel may comprise a gripping
portion. In this respect, the channel itself, or the separation
between an upper or outer portion of the sides of the channel, may
be narrower than the thickness of the edge of a flange to be
received, and in combination with this, the sides of the channel,
or the whole connector portion itself, may be formed from a
flexible material. In such embodiments, the sides of the channel of
the connector portion may flex a little outwards to receive the
flange edge and would exert an inward restoring force upon the
inserted flange such that it is gripped or held by the sides of the
channel. The connector portion sides may, in some embodiments, be
forcibly rotated outwards. In preferred embodiments, however, the
connector material is instead chosen to be inflexible, having a
high degree of stiffness so as to contribute to the structural
capability of the assembly.
[0037] A gripping portion of a connector portion channel could
comprise at least one tooth or protrusion which is attached to or
formed from, and projecting from the inside of, the channel and is
arranged to provide resistance against the flange moving outwards
from the channel. The inclusion of sawteeth or a sawtooth surface
profile on the inside of the channel that engages with the flange
is preferable, since it may improve the mechanical connection to
the flange or, in particular, to the bonding material or
adhesive.
[0038] Typically, a connector portion has such a channel on each
opposing side, so as to receive two flanges from two opposing
directions. The connector portion may comprise a piece of solid
material, or a solid strip, with a substantially H-shaped cross
section perpendicular to the edges of the flanges, or perpendicular
to the elongate axis defined by the length or largest dimension of
the connector portion. It is further envisaged that a connector
portion may have a different shaped cross section, such as that of
a flat strip or an L-shape, or two attached
[0039] U-shaped sections arranged back to back so as to receive a
flange edge in each U-section channel.
[0040] The connector portions, and in particular the channels
thereof, may be joined to flanges with adhesive or another bonding
material. As an alternative, or additionally, all or a part of the
length of the flange edges may be held together by a connector
portion or several connector portions comprising a clamp, or a
double sided clamp.
[0041] Typically, each connector portion is disposed along two
opposing flange edges of the first and second members. The
connector portions being disposed along and between the end edges
or faces of opposing flanges means that the connector portions may
be held together in an edge-to-edge arrangement to form an assembly
with a rectangular profile in which the length of the perimeter of
the rectangular profile is maximised. The connector portions being
attached to the members, and serving to attach the members
together, along the length of the flange edges results in the
edge-to-edge bonding which gives rise to the increased strength of
the assembly being applied along the length of each flange edge.
Preferably, each connector portion, or in particular each connector
channel, has a length equal to, or in some embodiments greater
than, the length of the flange edge inserted therein.
[0042] Preferably, each connector portion has an elongate structure
and each channel of each connector portion is aligned with this
elongate axis. Each connector portion may comprise a first and
second channel, wherein an edge of a flange of each of the first
and second members is held by the first and second channels,
respectively. Thus, it is preferable that the connector portion is
sufficiently long to hold a flange edge along its entire length.
This is advantageous in that the resistance to the separation of
members is maximised. Additionally, the connector portion also
serves to seal the assembly against contamination and fluid
penetration, and so disposing this sealing connector portion along
the entire length of each interface between opposing flanges
maximises this sealing effect.
[0043] Typically, each connector portion comprises a thermal
insulator. The thermal insulator is typically between the first and
second channels which receive or hold the flange edges. Thus, the
conduction of heat between the flanges of the first and second
members is minimised. This is advantageous in architectural
applications, such as when the assembly is installed on the outside
of a building as a glazing panel, which require limiting the
conduction of heat from one side, corresponding to the sheet of one
member, to the other side, corresponding to the sheet of the other
member.
[0044] The insulator may comprise a void, gap or cavity formed in
the connector portion. The presence of a void may reduce the
thermal conduction through the material from which the connector
portion is formed. The void may contain air or one or more gases,
or may be a partial vacuum or low-pressure environment with gas
density lower than atmospheric air density. The thermal insulator
may comprise a thermally insulating material such as polyamide,
polystyrene, polyurethane, or other polymer wool. Such materials
would serve to reduce the degree of heat conduction from one member
to the other by providing a thermal break or minimising thermal
contact or transmission along the interface where the two members
are connected or joined.
[0045] The two members being joined to one another by the connector
portions may comprise the members being attached, connected,
affixed, fastened, or adhered in various ways. Typically, each
connector portion is bonded to an edge of a flange of each of the
first and second members by an adhesive. Preferably the adhesive
comprises a silicone material. More preferably, the adhesive
comprises a structural sealant or a glazing sealant, and may be a
structural bonding adhesive. More preferably still, the adhesive
comprises a neutral curing silicone formulation suitable for the
structural bonding of glass and other building components.
[0046] Typically, the adhesive is disposed within the receiving
portion or channel within which each flange edge is inserted into
the connector portions. This advantageously provides a sufficiently
strong or structural bond between each member and the connector
portions, and thereby, between the two members via the connector
portion, so as to allow the assembly to function as a singular
structural unit.
[0047] Typically, the dimensions of the first member are
substantially the same as those of the second member. That is the
size and shape of each of the flanges of the first member and the
sheet of the first member are the same as those of the flanges and
sheet of the second member, respectively. In particular, the sheet
width, which may be defined as the linear separation between the
flanges of each member, is the same for both members so that the
flanges can be aligned between the two members. Additionally, since
it is preferable to maximise the depth of the flanges in order to,
in turn, maximise the depth of the assembly overall, each member
will have flanges whose depth corresponds to the maximum possible
depth achievable using the casting method of preparing glass
U-channels. Therefore, it is ideally preferable that the depth of
these flanges be the same for the first and second members.
[0048] Likewise, the height of the first and second members, that
is the linear extent of the members in a direction perpendicular to
the depth and the width as defined above, is preferably the same
for both members.
[0049] Typically, for each member the depth of each flange is
between approximately 8% and 30%, or between approximately 15% and
30% of the width of the sheet. Such aspect ratios are typical for
the cross sections of cast glass U-channels. For example,
U-channels are available having flange depths of 41-60 mm, and 70
mm, with typical sheet widths of 232 mm, 262 mm, 330 mm, and 500 mm
being typically available.
[0050] Typically, 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. Thus, the present arrangement provides
an aspect ratio that can be achieved in the plane of an assembly
panel combined with a vertical span greater than that which was
possible with prior art assemblies. Effectively, the increased
structural strength of the assembly permits a greater range of
heights, widths, and relative proportions than those which were
possible previously.
[0051] For instance, previously, U-channels having a height
sufficient to span between the floors of a building would need to
be approximately 0.25 m wide under typical load conditions.
[0052] The present glazing assembly may allow height greater than
3.0 m, or preferably 3.8 m, or more preferably 4 m, for example the
aforementioned 4.2 m typical building floor-to-floor separation, as
well as having a width that is 10% of this height, and more
generally 8% to 12% of this height. A wider assembly is also
advantageous in that fewer individual assemblies, and fewer joints
or gaps to be sealed in between adjacent assemblies, are required
for covering a given glazing area or width. The width may be
defined as the extent of the U-channel or assembly in a direction
across the sheet, between the ends from which the flanges project.
The height is the direction parallel with the plane of the sheet
and perpendicular to the width. The assembly is typically installed
or orientated such that this height axis is aligned vertically. The
increased structural capacity of the assembly allows an increased
vertical span to be achieved in a glazing assembly panel for a
U-channel or pair of U-channels having a given width. Hence, a
width-to-height aspect ratio of approximately 1:10 may be provided,
with the assembly still being able to function as a structural
glass unit under typical load conditions.
[0053] Typically, 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.
Thus, a hollow or tubular cross section may be provided. The
opposing first and second members may partly enclose a void.
However, this void may not necessarily be empty in use, and may
comprise air, another gas, or various materials selected for their
optical, acoustic, or thermal properties. The flanges and sheets
may form two opposing pairs which are orthogonal to one another and
which together surround an interior volume on four sides.
[0054] Providing a thermally insulating material between the sheets
of the two facing members would serve to reduce the degree of heat
transfer via convection or radiation from one member to the other.
In combination with embodiments wherein the connector portions are
formed so as to act as thermal breaks to limit heat transfer
through the members or the flanges thereof, as considered above,
for instance, the assembly may provide particularly advantageous
thermal insulation when installed.
[0055] Typically, the glazing assembly further comprises a closure
sealing an end of the tube. A tube defined by the two opposing
members may be open in that it comprises an opening at each end, in
the elongate axis of the tube, that is the axis parallel to the
flange edges and the connector portions. At least one of these
openings may be sealed by a closure or cap. This closure may be
adapted to attach to the assembly, for example by way of a force
fit, press fit, or fitting within, or around the outside of, the
tube opening. This may be effected, for example by way of a lip
formed around the periphery of the closure. Additionally or
alternatively, each closure may be affixed or bonded to the
assembly with an adhesive. This adhesive may be the same as or
different from an adhesive used to bond the flanges to the
connector portions.
[0056] More preferably, a closure is provided at each end of the
assembly, so as to form an enclosed unit. The assembly may thereby
be assembled and sealed in order to provide a unitary, sealed,
ready-to-install glazing panel that is free from contamination by
materials or contaminants on-site where the glazing is to be
installed. Preferably, the advantageous pre-sealing is performed in
a clean environment.
[0057] A closure may comprise an aperture passing through the
closure, via which liquid may flow or be exuded from the interior
of the assembly to the exterior. This aperture, or weep hole, may
be included so as to provide an outlet for condensation runoff and
pressure equalization. Additionally, the aperture may comprise a
plurality of sub-apertures which are sufficiently small as to
prevent insects or similarly larger contaminants passing through.
The aperture may comprise a grid, screen, or mesh in order to serve
this function.
[0058] Typically, the volume between the first and second members
comprises a thermal insulator. In particular, the volume between
the sheets of each of the first and second members, that is the
volume defined by or surrounded by the flanges and sheets of the
two joined members may include or be entirely or partially filled
with such an insulator. Preferably, the thermal insulator comprises
a thermally insulating material, that is one having a low thermal
conductance.
[0059] This is advantageous in glazing applications, as noted
above. Preferably, the insulator has a thermal conductance lower
than that of the otherwise unfilled void between the members.
Preferably, the thermal insulator has a structure that prevents or
reduces the passage or flux of heat across the void interior to the
assembly. This may be achieved, for example, by providing material
that blocks transmission by radiation between the two opposing
sheets of an assembly, or by having a structure that causes
convection currents in a gas within the assembly to be reduced,
restricted, or stopped, thereby alleviating the issue of heat
transfer via convection.
[0060] In some embodiments, the volume between the first and second
members may comprise an acoustically insulating material. The sound
attenuation through the assembly being enhanced by such a material
is advantageous in architectural applications.
[0061] The volume between the first and second members may comprise
a material through which light is diffusely transmitted. In
addition to obscuring the interior of the assembly, and in
particular the inner part of the connector portions, from view from
outside the assembly, the light-diffusing material which may be
enclosed by the members provides an increased privacy screen.
[0062] Typically, the material comprises glass fibre. This material
may provide the advantageous effects noted above, and may comprise
light stable binders attached to very thin, spun glass fibres,
which are woven into light and translucent glass fibre insulation.
The resulting enclosed, stationary air in the plurality of pockets
between glass fibres results in a high level of thermal insulation,
and achieves a strong light-scattering effect while minimising the
loss or attenuation of transmitted light.
[0063] The non-fireable, or non-combustible, glass fibre may be
held under slight compression, so as to ensure the material is not
loosely packed and that it fills the entire assembly volume, so
that no part of the interior volume of the assembly is unoccupied
by the insulating, light diffusing material and is hung from the
top of the tubular assembly.
[0064] The assembly could additionally or alternatively comprise
materials having light-diffusing or scattering, or thermally or
acoustically insulating properties. A number of optically
translucent materials which scatter or diffuse light transmitted
therethrough, and/or porous materials which trap a plurality of
stationary air pockets so as to minimise heat transfer through the
interior volume of the assembly are envisaged. For example, the
assembly may comprise an aerogel disposed in the interior volume in
order to serve this function.
[0065] Typically, an outer surface of a sheet of the assembly
comprises a plurality of grooves aligned substantially parallel to
the flanges of the assembly. These grooves may have a typical
periodicity of the order of a millimetre or several millimetres. In
use, when the assembly is disposed on the exterior of the building
as a glazing panel with the grooved surface facing outwards, and
the grooves aligned vertically, precipitation that is incident on
the glazing may run into the grooves and downwards, owing to the
force of gravity. Thereby, dirt, dust, or other materials on the
exterior glazing may be carried into the grooves and downwards to
the bottom of the glazing, or the facade or building overall. Thus
dirt is removed from the regions of the surface between the
grooves, and so this grooved surface profile may provide a
self-cleaning effect by allowing the crests to remain very
clean.
[0066] Thus, a self-cleaning effect may be achieved by way of a
physical surface profile, without need for a hydrophobic or
hydrophilic coating which previous self -cleaning solutions
require. The solution of a self-cleaning surface profile has lower
cost and greater longevity than such chemical-based solutions.
[0067] Typically, an outer surface of a sheet of the assembly has a
rough profile, which may include grooves as aforementioned, which
scatters light transmitted through the surface. Preferably such a
profile may be applied to the member that will be disposed on the
interior of a building or facade. In other words, the surface may
comprise deviations in the direction of the normal vector from the
normal vector of the plane of the sheet, and these deviations may
be of sufficient scale and magnitude that light is scattered upon
passing through the surface. The surface of the U-channel that will
define the outer face of an assembly when the assembly is installed
may be subjected to sand blasting, abrasive blasting, etching, or
enamelling to create a translucent or partially opaque frosted
glass effect. This may provide the additional advantage that the
insulation disposed within the interior volume of the assembly and
pressed up against an inside face of a sheet, which may otherwise
be visible owing to specular light transmission through glass with
smooth surfaces, be rendered invisible from outside the assembly.
Thus the roughened surface may render the glass fibres, for
example, of the insulation invisible by scattering the light
passing through the sheet.
[0068] In some embodiments, the glazing assembly further comprises
an internal protective element. This is typically formed as an
impact-resistant, or tough, piece of material, such as
thermoplastic polymer. The element is typically affixed to the
interior of the envelope or volume within the assembly, defined by
the first and second members. The inclusion of an additional, rigid
element within the assembly provides advantageous security and
safety improvements by affording the assembly increased impact and
intruder resistance. In the event that, when an assembly is
installed on the exterior of a building, for example, and the
external, or outward-facing toughened glass member is subjected to
an impact that is sufficient to break the glass of that member, the
protective element prevents that impact also causing damage or
breakage to the inward-facing member, and also prevents any access
to or incursion beyond the inside member and the interior of the
building.
[0069] The internal protective element is preferably formed from a
polycarbonate material. In such embodiments, the material is
preferably optically transparent, or substantially so, at least in
the visible wavelength range. This results in a glazing assembly
that provides improved protection against breakages due to impacts
and security from intruders without compromising the visual
appearance, or light transmission properties of the assembly. More
preferably still, an optically transparent protective element is
incorporated into an assembly comprising first and second glass
members having roughened, translucent, or light-diffusing qualities
or surface profiles. In this way the element is not visible or
visually detectable when the assembly is viewed from the
outside.
[0070] Typically 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. Such a form causes the element to act as
a barrier disposed across the internal volume of the assembly, the
barrier being disposed vertically in typical glazing installations.
The element may also comprise flanges that project from the sheet
portion and are adhered or affixed to the inside of the
assembly.
[0071] In accordance with the invention there is also provided 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.
[0072] Typically, 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.
[0073] Typically, the method further comprises disposing each
connector portion along two opposing flange edges of the first and
second members.
[0074] Typically, the method further comprises bonding each
connector portion to an edge of a flange of each of the first and
second members using an adhesive.
[0075] Typically, the method comprises 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 comprises sealing an end of
the tube, or each end of the tube, with a closure.
[0076] In accordance with the invention there is also provided a
modular glazing array comprising a plurality of glazing assemblies
according to those described above 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. Thus at
least one pair of joined, coplanar flanges of each glazing assembly
is adjacent to, faces, or is opposing or aligned with a pair of
joined coplanar flanges of another glazing assembly in the array.
That is, the assemblies may be disposed or lined up next to one
another, with the edges of each sheet of each member being aligned
with the edges of each respective sheet of an adjacent member, so
as to form a panel. The first and second sheets of the plurality of
glazing assemblies together present a first and second face,
respectively. When installed in a glazing application, these may
respectively correspond to an internal and external face.
[0077] In some embodiments, the plurality of glazing assemblies
comprises, or consists of, three or four glazing assemblies. The
modular glazing array may also comprise a window within the module.
The window may be a fixed window or an opening window. The window
may be a clear glazed bonded window. Owing to the structural
capabilities of the assemblies and the modular glazing array, such
a window may be included in the array without requiring further
framing or structural support.
[0078] The modular glazing array provides the advantage that
multiple assemblies may be installed as glazing in a single
installation action, by installing wide, multi assembly glazing
panels, with each carrying the advantage that they can perform
structurally and provide a good vertical span. Thus these
advantageous glazing panels may be applied to large or wider areas
on a building facade more quickly. It may also be possible to
create an aperture wider than an individual assembly, the aperture
being suitable for receiving window or door units. The structural
capability and strength of the assemblies and of the modular
glazing array panel means that these units can be supported.
[0079] Typically, different surface profiles are applied to the
internal and external facing sides of the modular array. These will
typically be selected, and the assemblies co-arranged, so that all
of, or adjacent, assemblies in the array present the same or
similar surface profile across each of the internal and external
faces.
[0080] Typically, a sealant is disposed between adjacent
assemblies. Thus the gaps between the assemblies are sealed, so
that sealed glazing panels having weather or precipitation
resistance are produced. Typically, sealant is applied to the outer
edges of the gaps between assemblies, but may also partially or
entirely fill each gap between the assemblies. This provides the
advantage that the produced arrays are waterproof, in particular
where a weatherproof sealant is used. This is advantageous in
exterior glazing applications. The sealant may comprise silicone,
and in particular a silicone formulated to provide weather
resistance, durability, adhesion, and movement flexibility, or any
of these properties. For example, it may be designed such that
thermal expansion and contraction is tolerated by the compression
or tension of the inter-assembly seals. Additionally, such a
flexible sealant may provide some flexibility or tolerance or
movement of or within the building structure.
[0081] Typically, the normal vectors of the sheets of adjacent
assemblies differ by no more than 10 degrees. In some embodiments,
the normal vectors of the sheets lie in a plane orthogonal to the
flanges and the sheets of the plurality of glazing assemblies. That
is, each assembly may be disposed in a position that is slightly
rotated with respect to an adjacent or another assembly in the
array about an axis parallel to the height or elongate axis of the
assembly tubes. This deviation may be substantially zero degrees,
corresponding to a planar or flat glazing array. In some other
embodiments, the angle of deviation may be approximately 10
degrees, or approximately or no more than 8 degrees, or
approximately or no more than 5 degrees, or approximately or no
more than 3 degrees. These values and ranges are particularly
advantageous when applied similarly to each pair of adjacent
assemblies in the array, corresponding to curved arrays of
increasing curvature radius.
[0082] Typically the assemblies are aligned such that the corner
edges of each assembly are parallel to and aligned with, or
proximal to the corner edges of an adjacent assembly. This results
in a plurality of flat sheets arranged along a line, which may in
some embodiments be a curved line to form a curved panel, or a
panel with a shape that approximates a curve. Typically, the
sealant amount, or the thickness of the sealant applied in each gap
will vary in order to accommodate the curve and the difference in
inter-assembly distances which this will produce between the front
and back faces of the array.
[0083] Typically, the sheets of each of the plurality of assemblies
are substantially parallel. Corresponding to planar embodiments in
particular, the sheets of the first and second members of each
assembly may be aligned in first and second parallel planes,
respectively. This results in a substantially flat panel.
[0084] In accordance with the invention there is also provided a
method of installing a glazing assembly according to those
described above, 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.
[0085] In accordance with the invention there is also provided a
method on installing a modular glazing array according to any of
those described above, 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 on 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.
[0086] In these methods of installation, the carrier, or the frame
thereof, may have a size and shape corresponding to the width, and
more generally the dimensions or perimeter, of the array. These
installation methods provide the advantage that each structural
array or assembly may be installed more rapidly by way of inserting
the assembly or array into the frame in a front-loading manner,
that is in a direction perpendicular to the primary plane of the
panel or the plane defined by the frame. The glazing may then be
held in place by affixing the removable lip so as to prevent
further movement of the glazing in this direction once it has been
installed.
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 facade 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 mm.times.808 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 facade.
[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 facade, 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 facade 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 wide.times.4.2 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.
* * * * *