Patent Description:
The present invention has been devised in particular due to the inventor's expertise in balcony systems. However, as will be apparent from the following disclosure, the invention may be embodied in different situations where balustrading is required.

Metal balconies are often specified in the plans drawn up by architects for new or existing buildings. These balconies may be decorative, but in many cases must be structurally secure and safe. A key part of balcony safety is the prevention of accidental falling from the balcony. For this reason, balconies typically have a balustrade, that is, a guard barrier extending around the perimeter of the balcony, with a height of about one metre, typically topped with a handrail.

Perhaps the simplest form of guard barrier around a balcony would be a wall. Although a wall would provide protection from the wind to the occupants of the balcony, equally it would restrict the view of the occupants of the balcony. It would also restrict light entering into the building.

It is known to use simple metal bars as a balcony balustrade. This has the advantage of simplicity and can be made to be suitably strong. However, if the bars are suitably strong (to provide adequate safety and to provide adequate support for a handrail), then they can be unsightly. Furthermore, depending on its construction, metal bars will provide no shelter from the wind to the occupants of the balcony.

It has therefore become common to use glass in balcony balustrades. Glass balustrades can provide an advantageous combination of light-transmission, wind shelter and strength. In order to provide adequate strength and toughness, laminated toughened glass is used. Laminated toughened glass consists of at least two sheets of glass adhered to each other by an adhesive interlayer disposed in a sandwich configuration between the glass sheets.

More recently, there has been focus on improving the fire safety of high rise buildings, such buildings being of the type that may have balconies fitted. Additionally, fire regulations for such buildings have changed. Accordingly, there is now a strong desire to design and build balconies so that the balconies contain no combustible materials.

Laminated toughened glass cannot therefore be used for balcony balustrades because the adhesive interlayer is combustible. Typical interlayer materials are polyvinyl butyral (PVB) and ethylene vinyl acetate (EVA).

<CIT> describes a system having vertical sections defining surface parts, where the parts are provided with several glass plates with less thickness than their length. The glass plates have the same dimensions or have dimensions which are integral multiples of low dimension. Short frontal edges of the plates are fixed directly or via a reception wedge, with vertical sections, where the wedge is in geometric correspondence with the vertical sections. The vertical sections are connected to each other by support sections. The support sections have a reception slot for receiving the edges of plates.

<CIT> describes a fencing system comprising: a top rail; a lower rail; and glass panels for extending between the top rail and the lower rail. The top rail and the lower rail are provided with connectors extending therefrom for holding the glass panels. The glass panels provide the necessary support between the top and lower rails, in the form of a barrier therebetween having a length that is generally uninterrupted between the ends of the fencing system, other than by the glass panels and the provision of air gaps between the glass panels.

<CIT> discloses a glass balustrade in which glass panels are supported at their lower ends by support members that receive the glass panels in a slot.

It is possible to manufacture toughened glass in monolithic form, i.e. not in a laminated form. This is advantageous in the context of balustrading in that it avoids the inclusion of combustible materials in the glass. Monolithic toughened glass can be manufactured by forming a glass panel to a required size, with edges ground appropriately, and then subjecting the glass panel to a heating and cooling treatment in which compressive stress is set up in surface regions of the glass panel with balancing tensile stressed in a central region of the glass panel. It is found that the high compressive stress in the surface regions significantly reduce the risk of accidental impact causing breakage of the glass panel.

However, the present inventor has realised that even toughened monolithic glass raises certain safety issues when used in balustrading. Beyond a certain level of impact, as for laminated glass, toughened monolithic glass can break. When laminated glass breaks, the interlayer typically holds the broken sheets of glass together. The result is that the laminated glass panel crazes and has much reduced strength, but tends to remain in position, providing at least some barrier effect. However, when toughened monolithic glass breaks, the breakage typically results in destruction of the integrity of the glass panel. Pieces of the glass panel can fall away. In the context of a balcony on a building such as a high rise building, this case present a significant safety hazard below. Furthermore, breakage of the panel results in the presentation of an opening in the balcony balustrade, increasing the risk of falling from the balcony.

There are other known options to increase the strength of glass. One such option is the incorporation of a wire mesh into the glass. This is sometimes used in windows are a security feature. Such glass may be referred to as Georgian wired glass. However, typically the glass is not toughened and the glass panel is therefore liable to breakage when subjected even to mild impacts.

It is possible to produce laminated glass with a wire mesh. However, this again suffers from the problem that the interlayer between the glass sheets is combustible.

Accordingly, in a first aspect, the present invention provides a balustrade arrangement according to claim <NUM>.

In a second aspect, the present invention provides a balcony incorporating a balustrade as set out in claim <NUM>.

In a third aspect, the present invention provides a method for the installation of a balustrade as set out in claim <NUM>.

An advantage of the invention is that the balustrade provides suitable light-transmission and shelter from wind. Although the individual glass slats are liable to break under sufficient impact load, typically such load would be concentrated on only one slat. Breakage of one slat would leave a gap corresponding to the one slat and its associated apertures with the adjacent slats. Such a gap is sufficiently narrow that the balustrade would still present a suitable temporary safety barrier, allowing work to be carried out to replace the broken slat with relative ease.

Optional features of the invention will now be set out. These can be applied singly or in any combination with any aspect of the invention, unless the context demands otherwise.

The small width of the slats and the small width of the apertures allows the slats to be fixed in position without the need for holes to be drilled through the slats. Accordingly, it is a preferred feature of the invention that the slats have no enclosed holes formed through them. According to the invention, the slats are fixed in position via clamping means. The clamping means comprises bolts extending through the spacing gaps between adjacent slats.

The slats may have any suitable shape. They may for example be rectangular in elevation view (that is, when viewed so that the width direction and the height direction are in the plane of the view). However, other shapes are possible, depending on the required aesthetics of the balustrade, such as trapezoidal, curved, arc-shaped, S-shaped. Where the width of the slats is not consistent along the height direction, the average width is to be used, for the width of the slats and for the width of the apertures. The slats may have matching shapes to each other or some or all of the slats may have a different shape to each other.

Also disclosed herein are arrangement in which there are two or more rows of slats in the balustrade. These rows may be offset from each other, such as being staggered in the forwards and rearwards direction. It will be understood that the arrangement of slats here still extends substantially laterally, notwithstanding the staggered nature of the arrangement. In this case, when viewed in elevation view, the slats may at least partially overlap with each other while still providing spacing gaps between the slats. In this arrangement, when one slat is removed from the balustrade to form a breakage gap between adjacent remaining slats, the width of the breakage gap, when viewed in elevation, can be less than the slat width. Accordingly, with this arrangement it is possible to ensure that the breakage gap is relatively small, even when relatively wide slats are used.

In a typical balustrade, there may for example be at least <NUM> slats provided.

The width of the slats may be not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM> or not more than <NUM>. The width of the slats is preferably not less than <NUM>. For example, a slat width of about <NUM> may be suitable.

The width of the apertures may be not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, not more than <NUM>, <NUM>, not more than <NUM>, not more than <NUM> or not more than <NUM>. The width of the apertures is preferably not less than <NUM>. For example, an aperture width of about <NUM> may be particularly suitable. This corresponds to a width that would permit passage of a typical bolt shank diameter that may be used to secure the slats.

More generally, it is possible to define a linear occupation ratio of the glass slats in the width direction of the balustrade, when the balustrade is viewed in elevation view. This therefore gives an indication of the amount of aperture provided through the balustrade. Accordingly, the glass slats may occupy not less than about <NUM>%, not less than about <NUM>%, not less than about <NUM>%, not less than about <NUM>%, not less than about <NUM>%, not less than about <NUM>%, not less than about <NUM>%, not less than about <NUM>%, not less than about <NUM>% or not less than about <NUM>% of the width of the balustrade. In some embodiments, the linear occupation ratio may be <NUM>%.

The thickness of the slats is preferably suitable to provide adequate strength for the balustrade. For example the thickness of the slats may be at least <NUM>, more preferably at least <NUM>, at least <NUM> or at least <NUM>. Suitable thickness values are, for example, <NUM> or <NUM>.

The balustrade may be provided with a hand rail formed at its upper extremity. The hand rail may be attached to the glass slats. In some embodiments, the glass slats support the hand rail without additional support (such as from posts or frame members). In this way, the hand rail may provide a degree of reinforcement to the balustrade when one of the glass slats is broken, and permits the maintenance of a safety barrier (the hand rail itself) across the gap left by the broken slat.

The balcony typically includes a fascia arrangement, intended to present a neat finish at the external surface of the balcony, typically covering a frame of the balcony. The fascia may include an angled lip region, disposed to catch broken glass that may otherwise fall from the balcony. The angle of the lip is preferably configured to direct any broken glass back inwardly onto the balcony.

Embodiments illustrating the principles of the invention will now be discussed with reference to the accompanying drawings in which:.

<FIG> show schematic views of a balcony <NUM> incorporating a balustrade <NUM> according to an embodiment of the invention, wherein the balcony <NUM> is attached to a building <NUM>. As is conventional, the balcony <NUM> is attached to the building <NUM> in register with a window <NUM> and/or door <NUM> of the building, allowing an occupant of the building access to the balcony.

The balcony <NUM> is typically attached to the concrete slab of a floor of the building, for example using cast-in anchors, with attached stubs/arms. These features are not shown in the drawings because these features are not visible during normal use of the balcony. In preferred embodiments, the balcony may be provided in the form of a cassette that slides on to stubs/arms projecting from the building. The balcony has decking <NUM>, soffits <NUM> below and fascia <NUM>, <NUM>, <NUM> at the front and sides.

Balustrade <NUM> extends around the perimeter of the balcony and defines the usable space on the balcony for the occupier. Typically, the balustrade is fixed to the balcony by fixings that are hidden from sight by the fascia <NUM>.

In the embodiment shown in <FIG>, the balustrade is formed from a series of monolithic toughened glass slats <NUM> (seen best in <FIG>), arranged in a lateral direction (corresponding to the general direction of extension of the balustrade). The slats each have a width W in the lateral direction up to <NUM> from a first lateral side to a second lateral side of a slat. Adjacent slats are spaced apart from each other by a spacing gap G of at least <NUM>. Spacing gap G is smaller than the width W of the slats. As can be seen, the slats <NUM> are arranged so that, when one slat is removed from the balustrade to form a breakage gap between adjacent remaining slats, the width B of the breakage gap in the lateral direction is at most <NUM>. In this embodiment, the slat width W is about <NUM>, spacing gap G is about <NUM> and therefore breakage gap B is about <NUM>. Provided that only one slat is broken, therefore the gap in the balustrade is suitably narrow to mean that there is only a low risk of falling through the balustrade.

A handrail <NUM> is provided at the top of the balustrade. This is in the form of an aluminium cap that serves to connect the tops of the glass slats. In the event of breakage of one of the slats, the handrail <NUM> remains in place, providing an effective temporary safety barrier at an appropriate height for adults.

These features mean that repair of the balustrade can be carried out without the need to bring into effect elaborate safety features, such as workers wearing harnesses or the provision of edge protection.

<FIG> shows a schematic view of a monolithic toughened glass slat <NUM>. <FIG> shows a schematic plan view of part of a balustrade according to an embodiment of the invention, corresponding in substance to the balustrade illustrated in <FIG> but without the handrail. <FIG> shows the part of the balustrade of <FIG> in sectional plan view, with dimensions W, B and G illustrated.

As mentioned previously, the use of monolithic toughened glass means that there is no need to use laminated glass, which has a combustible interlayer. This improves the fire safety of the balustrade. A further drawback of laminated glass is that if both sheets of the laminated glass break, there resultant broken glass has a 'floppy' form.

The use of a slatted arrangement for the balustrade means that, if one or two panels break, the balustrade is still suitably strong.

A practical benefit of the use of glass slats is that replacement slats can be held in stock by the balustrade manufacturer. Balconies are typically designed bespoke to a project and therefore if large area glass panels are used for the balustrade, these are typically manufactured to order, giving rise to a significant lead time (e.g. about <NUM> weeks).

A further advantage of the use of glass slats is that there is only limited wastage for the supplier cutting the glass sheet when manufacturing the monolithic toughened glass slats.

Furthermore, the use of slats of limited widths effectively eliminates manual handling risk of the slats in the factories.

It is possible to use low iron monolithic toughened glass slats. Such glass is advantageous because joins are less visible and there is reduced nickel sulphide risk.

<FIG> shows a schematic side view of a balcony incorporating a balustrade according to an embodiment of the invention, including detail of the handrail and the attachment of the slats with respect to the balcony. The arrangement of glass slats <NUM>, handrail <NUM> with respect to the balcony <NUM> is similar as for the embodiment shown in <FIG>. The slats <NUM> are attached to the balcony at their base, the attachment being hidden in normal use by fascia <NUM>. However, in <FIG>, the attachment is shown in outline, as is the lower part of three representative slats. In this embodiment, the slats have width W115 mm and spacing gap G of <NUM>. This spacing gap is significant because it permits the use of M6 or M8 bolts (which have a shank of diameter <NUM> and <NUM>, respectively) to fit in the spacing gap. These bolts <NUM> are illustrated in <FIG>. In this embodiment, in each gap between adjacent slats there is an upper bolt and a lower bolt. These extend through the spacing gap. They attach between metal (e.g. aluminium) plates (not shown) that extend along the lateral direction of the balcony, thereby clamping the slats between them. The advantage of this is that there is then no need for the slats to have holes formed through them for the passage of the clamping bolts. This is significant because cutting holes through glass, although possible, is time-consuming and relatively difficult.

<FIG> shows a partial sectional view of the balcony and balustrade of <FIG>. This view shows the clamping bolts <NUM> extending in the spacing gap between adjacent glass slats. As shown in <FIG>, the glass slat is offset from the front face of the fascia <NUM>, in this case by about <NUM>. The fascia has a top lip <NUM> that inclines backwardly towards the balustrade. The intention of this feature is to provide a catch for broken glass in the event that one or more of the slats is broken. The inclined top lip of the fascia will catch broken glass to reduce or prevent glass fragments falling from the balcony and will direct the broken glass back into the balcony.

<FIG> shows a schematic sectional plan view of a not belonging to the claimed invention. In this embodiment, slats 220a and 220b are arranged in series substantially along a lateral direction of the balustrade, but the slats are staggered in the forwards and rearward direction. The effect of this is that, if desired, a front row of slats 220a can partially overlap a rear row of slats 220b. This is advantageous in the sense that it can reduce the total amount of elevation view gap between slats, which in turn increases the wind shelter provided by the balustrade.

As shown in <FIG>, there is a metal plate <NUM> that is part of a clamping arrangement at the base of the slats, the front row of slats 220a sitting in front of the plate <NUM> and the rear row of slats 220b sitting behind the plate <NUM>.

<FIG> shows a schematic elevation view of part of a balustrade, similar to <FIG>. <FIG> shows the part of the balustrade of <FIG> in sectional plan view. As can be seen from <FIG>, it is possible to identify a width W in the lateral direction for each slat. Adjacent slats are spaced apart from each other by a spacing gap G. The direction of measurement of this spacing gap differs from the first embodiment. However, the principle of the spacing gap is the same. For example, it can be considered to be the smallest available gap measurable in any direction between adjacent slats. As can also be seen from <FIG>, when one slat is removed from the balustrade to form a breakage gap between adjacent remaining slats, the width B of the breakage gap, when viewed in elevation, can be less than the slat width W. Accordingly, with this arrangement it is possible to ensure that the breakage gap is relatively small, even when relatively wide slats are used.

Claim 1:
A balustrade arrangement (<NUM>) comprising a plurality of slats (<NUM>) of monolithic toughened glass arranged in series substantially along a lateral direction, the slats (<NUM>) each having a width (W) in the lateral direction up to <NUM> from a first lateral side to a second lateral side of a slat, adjacent slats being spaced apart from each other by a spacing gap (G) of at least <NUM>, the spacing gap (G) being smaller than the width (W) of the slats (<NUM>), the slats (<NUM>) being arranged so that, when one slat is removed from the balustrade (<NUM>) to form a breakage gap between adjacent remaining slats, the width (B) of the breakage gap in the lateral direction is at most <NUM>, characterised in that:
the slats (<NUM>) are supported and clamped at their lower end to fix the slats in position via clamping means, the clamping means comprising bolts (<NUM>) extending through the spacing gaps between adjacent slats.