Field of the Invention

The present invention relates to a balustrade. It has particular, but not necessarily exclusive, applicability to a balustrade for outdoor applications, such as for balconies.

Background

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). Summary of the invention

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.

The present invention has been devised in light of the above considerations.

Accordingly, in a first aspect, the present invention provides a balustrade arrangement comprising a plurality of slats of monolithic toughened glass arranged in series substantially along a lateral direction, the slats each having a width in the lateral direction up to 300 mm 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 of at least 6 mm, the spacing gap being smaller than the width of the slats, the slats being arranged so that, when one slat is removed from the balustrade to form a breakage gap between adjacent remaining slats, the width of the breakage gap in the lateral direction is at most 500 mm.

In a second aspect, the present invention provides a balcony incorporating a balustrade according to the first aspect. In a third aspect, the present invention provides a method for the installation of a balustrade according to the first aspect, wherein the glass slats are supported and clamped at their lower end using a clamping arrangement.

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.

Still further, 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. The slats may be fixed in position via clamping means. The clamping means may comprise 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.

There may be provided 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 10 slats provided. The width of the slats may be not more than 280mm, not more than 260mm, not more than 240mm, not more than 220mm, not more than 200mm, not more than 200mm, not more than 180mm, not more than 160mm or not more than 140mm. The width of the slats is preferably not less than 50mm. For example, a slat width of about 115mm may be suitable.

The width of the apertures may be not more than 100mm, not more than 90mm, not more than 80mm, not more than 70mm, not more than 60mm, not more than 50mm, not more than 40mm, not more than 30mm, not more than 20mm, 18mm, not more than 16mm, not more than 14mm or not more than 12mm. The width of the apertures is preferably not less than 2mm. For example, an aperture width of about 10mm 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 50%, not less than about 55%, not less than about 60%, not less than about 65%, not less than about 70%, not less than about 75%, not less than about 80%, not less than about 85%, not less than about 90% or not less than about 95% of the width of the balustrade. In some embodiments, the linear occupation ratio may be 100%.

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 10mm, more preferably at least 12mm, at least 14mm or at least 16mm. Suitable thickness values are, for example, 15mm or 19mm.

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.

The invention includes the combination of the aspects and preferred features described except where such a combination is clearly impermissible or expressly avoided.

Summary of the drawings

Embodiments illustrating the principles of the invention will now be discussed with reference to the accompanying drawings in which: Fig. 1 shows a schematic perspective view of a balcony incorporating a balustrade according to an embodiment of the invention, the balcony attached to a building.

Fig. 2 shows the balcony of Fig. 1 , viewed from below.

Fig. 3 shows the balcony of Fig. 1 , viewed from the front.

Fig. 4 shows the balcony of Fig. 1 , viewed from the side.

Fig. 5 shows the balcony of Fig. 1 , viewed from inside the building.

Fig. 6 shows a schematic view of a monolithic toughened glass slat.

Fig. 7 shows a schematic elevation view of part of a balustrade according to an embodiment of the invention.

Fig. 8 shows the part of the balustrade of Fig. 7 in sectional plan view.

Fig. 9 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.

Fig. 10 shows a partial sectional view of the balcony and balustrade of Fig. 9.

Fig. 11 shows a schematic sectional plan view of a balustrade according to another embodiment of the invention.

Fig. 12 shows a schematic elevation view of part of a balustrade according to another embodiment of the invention, similar to Fig. 11.

Fig. 13 shows the part of the balustrade of Fig. 12 in sectional plan view.

Detailed Description of the Invention

Aspects and embodiments of the present invention will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. All documents mentioned in this text are incorporated herein by reference.

Figs. 1 to 5 show schematic views of a balcony 100 incorporating a balustrade 102 according to an embodiment of the invention, wherein the balcony 100 is attached to a building 104. As is conventional, the balcony 100 is attached to the building 104 in register with a window 106 and/or door 108 of the building, allowing an occupant of the building access to the balcony.

The balcony 100 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 110, soffits 112 below and fascia 114, 116, 118 at the front and sides.

Balustrade 102 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 114. 116. 118. In the embodiment shown in Fig. 1 -5, the balustrade is formed from a series of monolithic toughened glass slats 120 (seen best in Fig. 5), 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 300 mm 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 6 mm. Spacing gap G is smaller than the width W of the slats. As can be seen, the slats 120 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 500 mm. In this embodiment, the slat width W is about 100 mm, spacing gap G is about 10 mm and therefore breakage gap B is about 120 mm. 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 130 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 130 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. 6 shows a schematic view of a monolithic toughened glass slat 120. Fig. 7 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 Figs. 1-5 but without the handrail. Fig. 8 shows the part of the balustrade of Fig. 7 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 12 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. 9 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 120, handrail 130 with respect to the balcony 100 is similar as for the embodiment shown in Figs. 1-5. The slats 120 are attached to the balcony at their base, the attachment being hidden in normal use by fascia 116. However, in Fig. 9, the attachment is shown in outline, as is the lower part of three representative slats. In this embodiment, the slats have width W 115 mm and spacing gap G of 10 mm. This spacing gap is significant because it permits the use of M6 or M8 bolts (which have a shank of diameter 6 mm and 8 mm, respectively) to fit in the spacing gap. These bolts 132 are illustrated in Fig. 9. 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. 10 shows a partial sectional view of the balcony and balustrade of Fig. 9. This view shows the clamping bolts 132 extending in the spacing gap between adjacent glass slats. As shown in Fig. 10, the glass slat is offset from the front face of the fascia 116, in this case by about 60 mm. The fascia has a top lip 134 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. 11 shows a schematic sectional plan view of a balustrade according to another embodiment of the 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. 11 , there is a metal plate 222 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 222 and the rear row of slats 220b sitting behind the plate 222.

Fig. 12 shows a schematic elevation view of part of a balustrade, similar to Fig. 11. Fig. 13 shows the part of the balustrade of Fig. 12 in sectional plan view. As can be seen from Fig. 12, 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. 13, 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.

The features disclosed in the foregoing description, or in the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for obtaining the disclosed results, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

While the invention has been described in conjunction with the exemplary embodiments described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiments of the invention set forth above are considered to be illustrative and not limiting. Various changes to the described embodiments may be made without departing from the spirit and scope of the invention.

For the avoidance of any doubt, any theoretical explanations provided herein are provided for the purposes of improving the understanding of a reader. The inventors do not wish to be bound by any of these theoretical explanations.

Any section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise” and “include”, and variations such as “comprises”, “comprising”, and “including” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by the use of the antecedent “about,” it will be understood that the particular value forms another embodiment. The term “about” in relation to a numerical value is optional and means for example +/- 10%.