A SEATING SUPPORT BEAM This invention relates to a load bearing beam for supporting articles when the beam is to take a substantially curved or radiused configuration and more particularly to a seating support beam.
In the field of seating and more particularly in stadium or lecture hall seating there is often a requirement for the seating to be arranged in an arc. Where there are tiers or rows of seating, the radius of the arc will vary. Rows of seats towards the front of the seating will have a fairly tight radius whereas a row of seats towards the rear of the lecture hall or stadium will have a much greater radius. Seating is typically supported on substantial load bearing straight beams which are mounted on posts sunk into or attached to the flooring. The straight beams must be cut to size, fixed to the posts and, if two beams are required to join one another in between posts, then they need to be butt jointed. Because the beams are load bearing, it is extremely difficult, if not impossible, for the beams to be shaped into a curve on site except with the use of heavy duty machinery. The forces required are simply too great for ready installation by bending the straight beams into a desired shape between posts, jointing the ends of the beams. It is known to pre-bend beams off site but this requires significant planning and one or more intensive on site surveys.
In the accompanying drawings, Figure 1 is a plan view of a seating layout using conventional straight beams B onto which seats S are mounted. It will be appreciated from this drawing that the straight beams are not all of the same length and cannot, therefore, accommodate the same number of seats per length. Accordingly, a lot of planning is required to maximise seat density and to provide an aesthetically pleasing curvature for the seating.
It is an object of the present invention to seek to solve the problems associated with conventional straight seating beams when a row of seating is required in a curved configuration. Accordingly, one aspect of the present invention provides a seating support composite beam comprising a pair of substantially identical elongate half-beams interlocked with one another along at least a portion of their respective lengths. Preferably, each half-beam has an interlocking part to engage with a corresponding interlocking part of the other half-beam.
Conveniently, the interlocking part comprises a channel and a groove which are interlockable with a channel and a groove of the other half-beam.
Advantageously, one half-beam is interlocked with another half-beam such that an end of one half-beam is located between the ends of the other half-beam so that the half-beams overlap one another. Preferably, the end of one half-beam lies substantially midway between the ends of the other half-beam.
Conveniently, further half-beams are interlocked to produce a longer composite beam, the half-beams overlapping the half-beams to which they are interlocked.
Advantageously, the half-beams are of substantially identical cross- section. Preferably, the half-beams are of substantially identical length.
Conveniently, each half-beam has an interlocking part, a longitudinal axis and the half-beam is more flexible in one direction substantially normal to the longitudinal axis of the beam than in another direction which is substantially normal to the longitudinal axis of the beam and substantially normal to the one direction.
Advantageously, the interlocking part is on a major surface of the half- beam which defines a joint plane, the one direction being substantially normal to the joint plane and the longitudinal axis and the other direction being substantially parallel to the joint plane and substantially normal to the longitudinal axis.
Another aspect of the present invention provides a seating support half-beam comprising an elongate element having: an interlocking portion to engage with a corresponding interlocking portion of another half-beam to form a seating support composite beam; and an external surface which, in combination with an external surface of another half-beam, defines an external surface of the seating support composite beam formed by interlocking two half-beams.
A further aspect of the present invention provides a seating arrangement incorporating a seating support composite beam or seating support half-beam. Another aspect of the present invention provides a seating support beam comprising: providing seating support members at predetermined locations; 1) fixing at least a half-beam to one of the seating support members; 2) bending the at least one half-beam to allow fixing of the half-beam or another half-beam interlocked therewith to another seating support member;
3) fixing the or another half-beam to the other seating support member; and repeating 2) and 3) until the half-beams are fixed to the seating support members. Preferably, half-beams are interlocked with one another and the composite beam formed thereby is fixed to the seating support members.
A further aspect of the present invention provides a composite elongate element comprising a pair of substantially identical elongate half- elements interlocked with one another along at least a portion of their respective lengths.
Preferably, each half-element has an interlocking part, a longitudinal axis and is more flexible in one direction substantially normal to the longitudinal axis of the composite element than in another direction which is substantially normal to the longitudinal axis of the composite element and substantially normal to the one direction.
Conveniently, the interlocking part is on a major surface of the half- element which defines a joint plane between the two half-elements, the one direction being substantially normal to the joint plane and the longitudinal axis and the other direction being substantially parallel to the joint plane and substantially normal to the longitudinal axis. In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a plan view of three rows of seating in a curved configuration using conventional straight seating beams;
Figure 2 is a cross-section through an extrusion of a half-beam of a seating support beam embodying the present invention;
Figure 3 is a cross-sectional view of two of the half-beams of Figure 2, interlocked with one another to provide a composite seating support beam;
Figure 4 is a schematic representation of a beam embodying the present invention showing its longitudinal axis (X), a direction of flexibility (Z) and a direction of stiffness (Y);
Figure 5 illustrates the composite beam of Figure 3 shaped into a curve and comprising three half-beams of Figure 2;
Figure 6 is a plan view of a seating arrangement using seating support beams embodying the present invention;
Figures 7, 8 and 9 show installation steps for a seating support composite beam embodying the present invention; and Figure 10 is a perspective view of a seating support beam embodying the present invention shaped into a curved configuration and comprising a plurality of half-beams of common length.
Referring now to the Figures and in particular, Figures 2 and 3, a seating support composite beam 100 embodying the present invention is shown in Figure 3 and is of substantially l-shaped cross section. The composite beam 100 comprises two half-beams 1 of aluminium extrusion.
Each half-beam 1 has two parts each with a respective function. The first part is a major elongate surface 2 which has an elongate protruding rib 3 of dove-tail section and a correspondingly shaped dove-tail channel 4 therein. The rib 3 and channel 4 are inversions of one another so
that two identical half-beams 1 can be interlocked with one another by the rib 3 of each half-beam 1 being slid into and received within the channel 4 of the other half-beam 1. The two major surfaces of the two half-beams define between them a joint plane, in which the two half-beams interlock in the manner shown in Figure 3 to form the composite beam.
The second part of each half-beam 1 comprises the other three external surfaces of the half-beam 1 which form one half of the l-shaped cross-section of the composite beam. When two half-beams 1 are interlocked in the manner shown in Figure 3, the second parts of each of the two beams 1 form an external surface comprising the composite beam of I- shaped cross-section.
The l-shaped cross-section of the composite beam comprises a main external body 5 having upper and lower elongate flanges 6, 7 to which ground supports and seating can be attached. Ground supports such as posts 10 embedded or otherwise fixed to flooring are attached to the lower flange 7 and seating is attached to the upper flange 6 of the composite beam. The seating support composite beam shown in Figure 3 is load bearing and can therefore support the weight of seating mounted thereon together with the weight of seating occupants.
Preferably, internal webbing 8 is provided within the aluminium extrusion of each half-beam bridging the elongate joint surface 2 and the external surface 5.
The exact form of the interlocking rib and channel 3, 4 is not as important as its function which is to allow two substantially identical half- beams 1 to be interlocked with one another to form a composite beam such as that shown in Figure 3.
Likewise, the precise form of the external surface 5 and flanges 6,7 of the composite beam are not important as long as they fulfil the function of allowing seating to be attached to one part and supports to be attached to another part.
It should be appreciated that the half-beams 1 should be articles of common manufacture in that they are substantially identical and can therefore be slid together to produce the composite beam shown in Figure 3. In isolation, each half-beam 1 is flexible and can be readily curved or otherwise shaped.
The major surfaces of each half-beam 1 are the interlocking surface 2 defining the joint plane and one half of the external surface 5 of the composite beam. Referring to Figure 4, the structure of each half-beam 1 , including any webbing 8, is such that each half-beam 1 is, in isolation, relatively flexible in a direction (z) orthogonal to the longitudinal axis (x) of the half-beam 1 and the joint plane 2 of the beam 1. Further, in isolation, the beam 1 is stiff in a direction (y) orthogonal to the longitudinal axis (x) of the beam 1. Each half-beam 1 is therefore able to be bent more easily in its flexible (z) direction than in its stiffer (y) direction. This arrangement is shown schematically in Figure 4.
In isolation, the half-beams 1 are flexible in one direction (z) but still stiff in an orthogonal direction (y) and can therefore be readily bent in the flexible direction to adopt any curve desired on the site whilst maintaining their load-bearing characteristics. In essence, the use of the composite beam of two half-beams means the force required to bend a composite beam embodying the present invention is far less than the force to bend a conventional straight beam having the same load bearing characteristics.
When two beams 1 are slid together as shown in Figure 3, the composite beam allows the two half-beams to bend independently of one
another and slide with respect to one another. Even when in the composite beam configuration, the composite beam is still adequately flexible to allow manual bending with only portable tools and certainly does not require any heavy duty tools or metal forming equipment.
The support members or posts 10 for the composite beam are sunk in to the floor or attached to the floor as previously described. Each post 10 has a beam mount 11 into which a lower part 7 of the beam is received and a clamp 12 attached to the post to sandwich the beam in the beam mount of the post 10. This arrangement is shown in Figures 7, 8 and 9. The posts 10 define the arc which the beam must take.
Common lengths of beam 1 are then assembled and one end of the composite beam is inserted and fixed to a first post 101 as shown in Figure 8 and can then be pulled or levered into position (bending in the flexible direction (z) to take up the desired shape) against other posts 1011, 10111 as shown in Figure 9, where the beam is locked into position on each of the posts 101, 1011, 10111, by clamps 12. For straight sections of seating, conventional straight beams may be used. Another advantage of the beam embodying the present invention is that common lengths L of half-beam 1 can be used throughout any curved or radiused portions of seating. Only one length of the beam embodying the present invention needs to be delivered to the site since the beam can be slid together in a staggered or overlapping configuration as shown in Figures 5 and 10.
Referring to Figure 10, a curved section of composite beam is shown in which all of the half-beams 1 embodying the present invention are of common length L except for the two half end-pieces which are of a length less than L which is shown in Figure 10 to be L/x. Since the half beams 1 can be staggered with respect to one another no cutting of the half beams is
necessary except at the ends of the composite beam which means that much less cutting is required on site when installing the seating support beam. Further, it will be apparent that no joints or connectors are required between the beams since this function is carried out by the mutual interconnection of the half-beams about the joint plane 2. This feature also greatly assists the installation of the seating support beam and greatly reduces labour time and costs since no jointing is required between ends of lengths of beams. Preferably, the end of a half-beam lies halfway between the ends of the half- beam to which it is interlocked.
The half-beams embodying the present invention and indeed the resultant composite beam provide for an infinite range of radii to be produced on site without the need for pre-bent specially tailored sections of beam and dispense with the need for heavy machinery to be used on site to install seating support beams. Common length standard straight extrusions embodying the present invention can therefore be used in any radii installation without the need for accurate site surveys. Continuous unbroken and substantially seamless lengths of composite seating beams can be constructed without the need for separate connectors by sliding the common sections of extrusion together creating overlapping sections. The continuous lengths of beam require less support components, posts 10, which is an advantage in itself but also assists cleaning in and around the seating.
A seating support composite beam embodying the present invention allows the seating layout to adopt easily and with little fore-planning a perfect radius whereas most conventional seating systems are created by employing shorter lengths of straight beams that are angled around the radius in linear sections which does not produce a visually pleasing appearance and can compromise the seating density.
The common extrusions are able to bend independently of one another and slide past one another when configured as a composite beam. It requires
more energy to stretch material such as aluminium extrusion, than to bend it. This means that the beam can be more easily manipulated into position on site manually with assistance of only portable tools and without the requirement for heavy machinery or for pre-bent specially tailored sections.
It should be understood that whilst the above discussion is in relation to seating support beams, the invention also has applications in the railroad industry or any other industry where beams, tracks, rails, guides or the like are used in lengths and need to be bent or radiused whilst maintaining the load bearing characteristics of an equivalent single beam, track, rail or guide.
When used in this specification and claims, the terms "comprises" and "comprising" arid variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.
The features disclosed in the foregoing description, or the following claims, or 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 attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.