WO2016040992A1

WO2016040992A1 - A stud

Info

Publication number: WO2016040992A1
Application number: PCT/AU2015/000574
Authority: WO
Inventors: Ashok KRISHNAMURTHY; Alister Bennett
Original assignee: Asm Holdings Australia Ltd
Priority date: 2014-09-18
Filing date: 2015-09-18
Publication date: 2016-03-24

Abstract

A for constructing a wall formwork, comprising: two opposing wall supports; and a substantially planar spacer having a plurality of apertures therethrough, wherein the spacer is separately connectable to each of the two opposing wall supports such that when the spacer is connected to the pair of opposing wall supports the spacer retains the two opposing wall supports in a fixed, parallel relationship to each other.

Description

A STUD

TECHNICAL FIELD This invention relates to the field of wall studs and wall supports. Specifically, the invention relates to a modular stud for constructing a wall formwork. The invention further relates to a method of constructing a wall.

BACKGROUND

Studs are typically used to construct panel formworks for building walls. The formwork acts as a mould in which cement or concrete may be poured and left to cure or set. This method of constructing a wall is used in preference to taking delivery of precast concrete slabs or using concrete blockwork.

The studs themselves are used to create hollow formwork panels by attaching to fibre cement sheeting or other sheeting materials to construct formwork panels. The formwork is then placed in the desired location for the wall and filled with concrete, wherein the formwork provides a mould as the concrete sets, to form a loadbearing wall.

Typically a single formwork panel will comprise more than one stud, spaced at regular intervals to support the formwork, thus the flow of concrete into the cavities between the studs is impeded by the presence of the studs. This can lead to air pockets and voids within the substrate of the wall when set, having a potentially damaging effect on the integrity of the finished wall.

The studs remain entombed in the substrate of the finished wall, and as such, are consumables. A large number of studs are required to construct a unit or block. Accordingly, there is a desire to minimise the cost of each stud without compromising their functional capabilities.

There are further draw backs associated with the logistics of transporting and supplying large numbers of studs to a building site for constructing the necessary formworks on site. Various types of studs are used to construct formwork within the building industry. However, it is always desirable to design new studs to address or ameliorate the drawbacks described above.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the exemplary methods and materials are described herein.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

SUMMARY OF THE INVENTION According to a first embodiment of the invention, there is provided a stud for constructing a wall formwork, comprising:

two opposing wall supports; and

a substantially planar spacer having a plurality of apertures therethrough, wherein the spacer is separately connectable to each of the two opposing wall supports such that when the spacer is connected between the pair of opposing wall supports the spacer retains the two opposing wall supports in a fixed, parallel relationship to each other.

The stud of the present invention provides a modular stud in which three components are separately provided to construct the stud. Namely, two opposing wall supports are joined to the spacer to construct the stud. Essentially, each of the two opposing wall supports are configured to couple with the spacer at a connection.

Specifically, the wall supports provide a first coupling (e.g. female coupling) and the spacer is configured to provide a corresponding second coupling on opposing edges thereof (e.g. symmetrical male couplings). The connection formed between each wall support and the spacer is a T connection, and when completely assembled the two wall supports and spacer in-between form an T structure. The spacer when inserted between the two wall supports connects the two wall supports and effectively locks the stud together, in some embodiments, unreleasably.

In this manner, all wall supports are identical and the spacers may be provided in a range of different widths to form studs with differing widths that are selected according to the thickness of wall required. By modularising the stud in this manner a logistical burden is reduced, in that exact quantities of each width of stud required need not be stipulated upfront. Also, when not assembled, the spacer and wall supports are entirely separate so that they may be stacked one against the other for storage and transportation.

The stud of the present invention further provides advantages due to the ease of manufacture of certain embodiments. In a preferred embodiment the stud is manufactured from plastics. Injection moulding of a component relies on a good flow of molten material around a die, therefore, the more complicated the part-form the more complicated the tooling. However, the stud of the present invention is, when formed from plastics, formed from two different components (two wall supports and one spacer) both of which are substantially planar thus reducing the requirement for large amounts of material distribution within a die. Aside from the quality benefits of having good material flow within the die, the planar components to be moulded will enable an efficient setting time for the injection moulding cycle and further reduce the need for complex tooling costs.

A further advantage of the stud of the present invention is performance related. Due to the configuration of the stud, the wall formwork created therewith has fewer obstructions to the flow of a liquid substrate, such as concrete. This in turn reduces the formation of voids and other inclusions in the finished wall structure. The substantially planar spacer need not have a plurality of webs or ribs protruding into the space between the two opposing wall supports that can impede concrete flowing between the two wall supports.

As discussed above, a further advantage of the stud relates to ease of transport. When materials are being shipped over large distances the weight and volume of the goods to be transported will have a significant effect on the cost. The stud of the present invention, prior to assembly, is space efficient. The wall support and spacer can be packaged virtually flat pack because they are provided separately to be connectable. This allows for more efficient use of transport space, which can be lost to transporting empty space for products that do not nest well. The larger the numbers of studs to be transported, the more significant the savings realised. In contrast, when transporting conventional studs, shipping space is lost as a

conventional stud does not nest well, making them costly and inefficient to transport.

The plurality of apertures within the planar spacer may be configured to support a reinforcement bar. In another embodiment each of the plurality of apertures may be configured to support a plurality of reinforcement bars, in a spaced apart relationship.

In a first embodiment, each of the wall supports has a first outer surface that is substantially smooth. This first surface of each wall support faces outwardly when the stud is assembled. The two outwardly facing surfaces thus provide a contact surface for formwork sheeting to be attached on either side of the stud. The formwork sheeting may be mechanically connected to the stud by using screws, bolts, nails, studs, rivets, or other mechanical fasteners. The formwork may be connected to the stud with an adhesive or glue, or curable resin. A combination of mechanical fasteners and adhesive may be used to bond the spacer and the two wall supports together.

In this embodiment, each of the wall supports has a second inside surface opposing the first surface, the second surface configured to receive an edge of the planar spacer, such that the stud is configured to have an I-beam cross section.

In a preferred embodiment, the longitudinal edges of the planar spacer are crenulated. The crenulations may be of varying lengths such that at least one crenulation on opposing edges of the planar spacer penetrates into each of the opposing wall supports, respectively. At least one of the crenulations on opposing edges of the planar spacer is configured to abut each of the second surfaces of the wall supports, respectively.

The coupling on the wall supports may comprise the second surface of each wall support having a channel for receiving the opposing longitudinal edges of the planar spacer. The channel of the wall support is located along a central, longitudinal axis of the wall support. The channel may extend outwardly from the second surface of each wall support. The channel of the wall support may be of varying height. The channel may be segmented at regular intervals along the length of the wall support. The channel may have smooth internal surfaces. The internal surfaces of the channel may be configured to grip the edges of the planar spacer. The internal surfaces of the channel may comprise a protrusion for griping the edge portion of the planar spacer. The channel may be partially open thereby creating at least one passageway that extends through the wall support from the second surface to the first surface. The passageway may be configured to retain the crenulations of the planar spacer. The passageway may comprise a lip between the first surface and the second surface, against which a portion of the crenulation is retained. The passageway is dimensioned to prevent the crenulation retained therein from extending beyond the first surface of the wall support.

The coupling of the spacer may in the above embodiment comprise the crenulations of the edge of the planar spacer that are configured to be received within the channel of the wall support. The edge of the planar spacer may provide a detent to secure the edge within the channel of the wall support. The detent may be defined by a crenulation or be in the form of a ridge, tab or a barb to prevent incidental disconnection of the crenulation from the channel. The ridge or barb thereby prevents incidental disconnection of the planar spacer from the wall support. The ridges of adjacent crenulations may project from the crenulations in opposing directions to balance the forces transferred between the wall support and the planar member.

The crenulations may extend from the planar spacer away from the plane of the spacer. Adjacent crenulations may extend outward from the plane of the planar spacer in opposing directions. Projecting all the ridges in the same direction can lead to unbalanced loading of the stud that is all the forces between a wall support and the spacer are loading in the same direction. If all forces are unidirectional between the channels and respective crenulations, the stud will be susceptible to geometrical screw i.e. the I-beam cross section will not remain at right angles.

The wall support may further comprise a lateral detent to prevent movement of the planar spacer relative to the wall support once connected. The lateral detent may comprise a single protrusion that prevents relative lateral movement in a first direction between the planar spacer and the wall support. The lateral detent may comprise a pair of protrusions that prevent relative lateral movement in two opposing directions, between the planar spacer and the wall support.

A channel of each wall support may be configured to receive a pair of adjacent crenulations wherein each one of the pair of crenulations has a ridge and each ridge extends from the planar member in an opposing direction to the other ridge.

The wall supports are configured to be symmetrical about a central longitudinal axis.

The wall supports have undulating outer edges. The width of the wall support alternates at regular intervals between a first width and a second width, where the first width is less than the second width. This configuration of the wall support reduces unnecessary material from the stud without reducing overall structural performance of the stud.

The substantially planar spacer is rotationally symmetrical about all three primary axes. Accordingly the planar spacer, once longitudinally aligned between two opposing wall supports, will connect with the wall supports in any orientation. This feature reduces the ability for the planar spacer to be incorrectly oriented relative to the wall supports.

The second surface of each of the wall supports may further comprises a plurality of arcuate projections. The arcuate projections may be symmetrical about the central longitudinal axis of the wall support. The arcuate projections may extend across the second surface of each wall support. The arcuate projections may be aligned with the undulations along the edges of the wall support. A zenith of each arcuate projection is disposed on the second surface of the wall support to align with portions of maximum width of the wall support. A height of the arcuate projections varies around their radial boundary. The height of the arcuate projection is at a maximum along the central longitudinal axis of the wall support. The height of the arcuate projection is at a minimum at the zenith. The arcuate projection may be a stiffener.

In some embodiments, an inside surface of the wall supports may comprise stiffeners. The stiffeners are for providing strength to the wall support, and may extend only part way between the wall supports when assembled. In some embodiments, the stiffeners protrude less than 50% into the space between the wall supports. The stiffeners may be in the form of a web, a wedge or a generally planar member positioned, or integrally moulded in the wall support, to provide strength to the wall support and particularly the connection between the wall support and spacer.

In one embodiment, the modular stud may be formed from any one of the following materials; ABS; recycled ABS; Polystyrene; High Impact Polystyrene (HIPS) plastic and a combination of the above. The support members and the planar spacer may be made from the same material. The modular stud may be formed by injection moulding, vacuum forming or extrusion. In some embodiment the modular stud is between 500mm and 1500mm in length. In a specific embodiment, the modular stud is 1 100 mm in length. The planar spacer may be manufactured in standard widths of 100mm, 150 mm or 200mm.

In a further embodiment of the invention there is provided a method of constructing a wall, the method comprising the steps of:

(a) constructing a stud by connecting a substantially planar spacer between two separate opposing wall supports, the substantially planar spacer having a plurality of apertures therethrough; and (b) attaching formwork boards to the two opposing wall supports to form a wall formwork.

In a preferred embodiment where the wall to be constructed is a concrete wall, or a similar poured substrate solid wall, the method additionally comprises the steps of:

(a) positioning at least one reinforcement bar through one of the plurality of apertures within the substantially planar web of the stud; and

(b) pouring concrete into the wall formwork to cure.

At least two studs are used to construct a wall formwork, more depending on the length of the wall to be formed. As the concrete or alternative liquid substrate is poured into the wall formwork, the flow of concrete is impeded by any form on the second surfaces of the two opposing wall supports and any form on the opposing faces of the planar spacer. By configuring the surfaces of the stud to be planar and reducing the dimensions of any protrusions, the flow of concrete into the formwork is improved. Furthermore, the planar surfaces of the planar spacer provides minimal opportunities for air to become trapped between the spacer and the setting concrete, thereby reducing the opportunity for voids to form in the wall as the concrete cures. The wall supports further comprise a plurality of holes that extend from the first surface to the second surface. The holes within the wall support may be 2mm, 3mm, 4mm or 5mm in diameter.

These holes serve as expansion holes within the wall supports and allow for excess adhesive to flow therethrough when adhesively bonding the stud to a pair of formwork boards. In embodiments where the stud is to be affixed to formwork boards with moisture cure polyurethane, the holes serve to allow flow of the expanding adhesive to pass through the flange and form dome heads on the back, thereby increasing the bond strength of the adhesive.

Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred

embodiments of the invention, along with the accompanying drawings in which like numerals represent like components. BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are illustrated by way of example, and not by way of limitation, with reference to the accompanying drawings, in which:

Figure 1 is an isometric view of a stud, comprising two symmetrical wall supports and a planar spacer according to a first embodiment of the invention; Figure 2 is an isometric view of the planar spacer of the stud of Figure 1 ;

Figure 3 is a side view of the planar spacer of Figure 2, illustrating thickness variations of the spacer; Figure 4 is a plan view of the planar spacer of Figure 2, illustrating crenulated longitudinal edges;

Figure 5 is a plan view of a first side of a wall support; Figure 6 is a side view of the wall support of Figure 5, illustrating a series of channels extending from a second surface of the wall support;

Figure 7 is a plan view of the second surface of the wall support, illustrating a series of arcuate stiffeners that extend along the length of the longitudinal axis of the wall support and extend across the second face thereof;

Figure 8 is an isometric view of the wall support of Figure 5 from the first side;

Figure 9 is an isometric view of the wall support of Figure 5 from the second side;

Figure 10 is an exploded view of two opposing wall supports aligned with a planar spacer, prior to assembly; Figure 1 1 is a plan view of the assembled stud; of Figure 1 ; Figure 12 is an exploded isometric view of the two opposing wall supports and a planar spacer prior to assembly, illustrating cooperating features on each component to facilitate their connectivity;

Figure 13 is an end view of Figure 10, wherein the two opposing wall supports are aligned with the planar spacer, immediately prior to assembly;

Figure 14 is an end view of the assembled stud, illustrating an I-beam cross- section;

Figure 15 is a magnified view of the cooperating features for connecting a wall support to the planar spacer; Figure 16 is an isometric view of a wall formwork, illustrating the positioning of a plurality of studs between a pair of formwork boards, supporting a reinforcement bar, in preparation for receiving a fluidised substrate;

Figure 17 is a plan view of planar spacer according to a further embodiment of the invention;

Figure 17A is an enlarged view of the embodiment of Figure 17, illustrating an arrangement of crenulations along the longitudinal edge of the spacer; Figure 18 is a plan view of planar spacer according to a still further embodiment of the invention;

Figure 18A is an enlarged view of the embodiment of Figure 18, illustrating an arrangement of crenulations along the longitudinal edge of the spacer;

Figure 19 is a plan view of planar spacer according to a still further embodiment of the invention; Figure 19A is an enlarged view of the embodiment of Figure 19, illustrating an arrangement of crenulations along the longitudinal edge of the spacer;

Figure 20 is a plan view of planar spacer according to a still further embodiment of the invention;

Figure 20A is an enlarged view of the embodiment of Figure 20, illustrating an arrangement of crenulations along the longitudinal edge of the spacer;

Figure 21 is a plan view of planar spacer according to a still further embodiment of the invention; and

Figure 22 is an enlarged view of an embodiment of a wall support for use with the planar spacers of Figures 17 to 21.

DETAILED DESCRIPTION OF EMBODIMENTS

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments of the invention are shown. The invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

It is intended that all references in this specification to "concrete" are intended to encompass but are not limited to concrete, cement and other liquefied substrates that may be poured into the formwork for forming a wall.

Referring now to Figure 1 , there is illustrated a stud 100 for constructing a wall formwork, comprising: two opposing wall supports 120; and a substantially planar spacer 1 10 having a plurality of apertures 1 12 therethrough, wherein the spacer is separately connectable to each of the two opposing wall supports at a connection such that when the spacer is connected to the pair of opposing wall supports the spacer retains the two opposing wall supports in a fixed, parallel relationship to each other. The modular stud 100 comprises a single planar spacer 1 10 and two identical wall supports 120. The planar spacer 1 10 is attached between the two wall supports 120 approximately half way along their length, giving the stud 100 an I-beam shaped cross-section.

The features of the two components, the wall support 120 and the planar spacer 1 10 will now be described in more detail. Figure 2 shows the planar spacer 1 10 detached from the pair of support members 120. The spacer 1 10 is divided into five identical sections, each section comprising a central aperture 1 12.

The aperture 1 12 is configured to support a reinforcement bar 145 (rebar) passing therethrough i.e. the reinforcement 145 is passed through the aperture 1 12 substantially perpendicular to the plane of the spacer 1 10 see Figure 16. Around the periphery of the aperture 1 12a are a number of arcuate profiles. A central end profile 1 13 is mirrored in a longitudinal direction across the aperture 1 12. Further provided are two adjacent arcs 1 13a, 1 13b of smaller radii than the end profile 1 13. When a single rebar 145 is supported within the aperture 1 12 is will naturally centre itself in the central end profile 1 13. However, where two reinforcements 145 are disposed within the aperture 1 12, they will be supported by the two adjacent arcs 1 13a and 1 13b, preventing a single rebar 145 from sitting within the central end profile 1 13.

Accordingly, the profile of the aperture 1 12 will hold the reinforcements 145 in a spaced apart relationship within a wall formwork 140 in preparation for introducing a fluidised substrate. The spacer 1 10 is provided with crenulated edges 1 18. The crenulations along the edges are of differing lengths. Figure 2 illustrates crenulations 1 19 grouped into sets of four. These groups of crenulations 1 19 are interspersed between pairs of elongated crenulations. Each elongated pair of crenulations has a first elongated crenulation 1 14 biased towards a first side of the spacer 1 10 and a second elongated crenulation 1 16 biased towards the opposing side of the spacer 1 10.

The spacer 1 10 is configured such that it can be aligned to the support member 120 simply by aligning the length of the two components. The spacer 1 10 is not handed i.e. is rotationally symmetrical and thus will align and connect with a pair of support member 120 is any of its four possible orientations therebetween.

The elongated crenulations 1 14, 1 16 are intended to extend, at least partially into the wall supports 120 when the stud 1 10 is assembled. In the embodiment shown in Figure 2, the elongated crenulations 1 14, 1 16 are sufficiently long to penetrate the wall support 120 and in effect act as connection tabs. The groups of short crenulations 1 19 are intended to sit on a second surface 123 of the wall support 120. The interaction of the spacer 1 10 and the wall support 120 will be discussed in further detail later in the description.

At the periphery of the elongated connection crenulations 1 14, 1 16 is a detent, illustrated in Figure 4 as ridges 104 and 106, respectively. The ridge 104 is oriented away from the planar spacer 1 10 in an opposing direction to the ridge 106. In this manner the forces transferred by the elongated crenulations 1 14 and 1 16 are transmitted equally and in opposing directions, to assist in stabilising the assembled stud 100.

Figure 3 illustrates the planar spacer 1 10 is a side view which illustrates the opposing orientation on each pair of crenulations 1 14 and 1 16, biasing them in opposing directions. Viewing the spacer 1 10 in side view, also illustrates a variation in thickness that alternates from t1 to t2 along the entire length of the spacer 1 10. The material thickness of the spacer 1 10 is at a minimum at t1 which is disposed approximately central to the aperture 1 12. The material thickness increases to a maximum at t2 which is disposed approximately between each pair of elongated crenulations 1 14, 1 16. The thickness t1 to t2 varies between 2mm to 6mm and preferably varies between 3mm to 5mm. By varying the thickness of the spacer 100, the second moment of inertia of the stud 100 (the I-beam cross-section) is altered, to improve the load bearing capacity of the beam while optimising material use. This provides structural integrity to the stud 100, as the connection points between the wall supports 120 and the spacer 1 10 are located in the thicker regions of the spacer 1 10, providing additional strength in each region where the highest loads are transferred between the two components 120, 1 10. Figure 4 is a plan view of the planar spacer 1 10 and illustrates the additional length of crenulations 1 14 and 1 16 over the groups of crenulation 1 19. A shoulder 107 is illustrated to one side of the pair of crenulation 1 14, 1 16. The shoulder 107 can be provided on either side of the pair of crenulations 1 14, 1 16. The shoulder 107 is a raised protrusion that extends substantially perpendicular to the plane of the spacer 1 10. A first side of the shoulder 107 has a flat face 108 that is substantially

perpendicular to the plane of the spacer 1 10 and which acts as a stop to resist lateral movement of the spacer 1 10 relative to the wall support 120 when the two are connected. A second face 108a of the shoulder 107 is inclined, and smoothly transitions the protrusion of the shoulder 107 back towards the plane of the spacer 1 10. The wall support 120 provides cooperating structure against which the flat face 108 of the shoulder 107 can abut.

In between each crenulation of the groups of crenulations 1 19 there is a T- shaped slot 1 17. The T-shaped slots provide a physical feature for co-locating the spacer 1 10 to each of the wall supports 120. Furthermore, the T-shaped slots 177 allow adhesive to flow therethrough when adhesive is applied to the first surface 122 of the wall support 120 which adds to the bonded strength of the stud 100. In the plan view of Figure 4, it is also illustrated how the aperture 1 12 is configured to support one or a plurality of reinforcing bars 145. Once the planar spacer 1 10 is oriented in the predetermined orientation, gravity will settle the reinforcement/s 145 into a stable location in anticipation of the liquid substrate being introduced. The planar spacer 1 10 can be formed from a resilient plastic material or composite. In a preferred embodiment the spacer 1 10 is made from any one of the following materials; ABS; recycled ABS; Polystyrene; High Impact Polystyrene (HIPS) plastic or any combination of the above. Figure 17 to 21 illustrate alternative embodiments of the spacer 210, 310, 410,

510 and 610. These alternative embodiments provide different width to length ratios and configurations of the spacer and can be manufactured in a range of standard sizes for any particular application. In Figures 17 to 21 , like reference numerals indicate similar features to those described in reference to spacer 1 10. Each of the spacers illustrated in Figures 17 to 21 are configured to mate with one or more wall supports 220 as illustrated in Figure 22.

It is noted that in the spacers 210, 310, 410, 510 and 610, there are no short groups of crenulations. Rather, those spacers are provided with a greater frequency of elongated connection crenulations 214 and 216, 314 and 316, 414 and 416, 514 and 516, and 614 and 616 along their side lengths. The greater number of connection crenulations compared to spacer 120 provides a shorter spacing between the connection crenulations which, when assembled to engage with wall supports 220, results in a stronger connected structure.

In-between connection crenulations 214 and 216 et al, is a single short crenulation 219, 319, 419, 519, 619. While only one crenulation is illustrated in these embodiments, a group of crenulations may be provided instead. The single crenulation 219 in each embodiment of Figures 17 to 21 has on one or both of its faces short parallel strengthening ribs 225, which are designed to provide strength to the portion of the spacer at the single crenulation across which the ribs extend.

Figure 5 illustrates a first surface 122 of the wall support 120. This first surface 1 12 is substantially planar and provides a mounting surface for a formwork board 142. There can be advantages of having physical protrusions on this surface to aid mechanical adhesion between the boards 142 and the wall support 120. However, in the embodiment of Figure 5, the first surface 1 12 is smooth to receive adhesive or moisture-curing polyurethane to bond with the board 142.

The wall support 120 has undulating edges 134 that extend the longitudinal length of the support 120. These are primarily for material reduction and assist in keeping the mass of the stud 100 to a minimum, facilitating efficient material usage. Figure 5 further illustrates a plurality of circular apertures 124, equidistantly spaced along the wall support 120. These apertures 124 serve a number of purposes. They assist in the manufacturing of the wall support 120, they reduce material in the part and they provide expansion holes for egress of excess adhesive during the bonding of the stud 100 to formwork boards 142. Furthermore, where bonding agents are used that require air to cure fully, the aperture 124 provide exposure to air to assist in curing.

Figure 5 illustrates a plurality of quadrilateral apertures extending centrally, the entire length of the first surface 122. The apertures are grouped into elongate rectangular slots 130 followed by a subsequent set of three square apertures 132. Figure 5 also shows a plurality of round aperture or holes 124 that extend the entire length of the first surface being located towards the boundary of the first surface 122. The square apertures 132 allow adhesive to flow from the first surface 122 of the wall support 120 and into the T-shaped slots 177 of the planar spacer 1 10. This adhesive, when applied, will fill the apertures 132 and set therein and further enhance the bonded strength of the stud 100. The elongate rectangular slots 130 are bounded by a seat 131 . This provides a mechanical feature, upon which the ridges 104, 106 of the resilient elongated crenulations 1 14, 1 16 are retained. As a wall support 120 and a spacer 1 10 are brought together the crenulations 1 14, 1 16 (biased in opposing directions) are passed from the second surface 123 of the wall support 120 to the first surface 122, through the slots 130, such that the ridges 104, 106 snap over the seat 131 and become locked together. The slots 130 and the seats 131 are symmetrical to accommodate either of the crenulations 1 14, 1 16 so that the planar spacer 1 10 is not a handed component.

Figure 6, is a side view of the wall support 120 from Figure 5, exemplifying the smooth first face 122 of the wall support 120. In contrast the second face 123 of the wall support 120, which is configured to receive and secure the crenulated edge 1 18 of the planar spacer 1 10 thereto.

Figure 7 and 6 in combination illustrate a series of channels 127 and 128 that centrally extend the entire longitudinal length of the wall support 120. The channel 127 comprises three short channels 127a, 127b and 127c. These three channels 127a, 127b, 127c are open at face 123 to receive crenulations 1 19 and open on face 122 coincide with the square apertures 132 on the first face 122 of the wall support 120. The elongate channels 128 comprise a pair of parallel side walls 136a, 136b. There is a gap between the side walls 136a, 136b providing an opening to channel 128 allowing the elongate crenulations 1 14, 1 16 to pass therethrough to secure the wall support 120 to the planar spacer 1 10. It is contemplated that the channels 127 and 128 can be formed within the body of the wall support 120. However, in this preferred embodiment the channels 127, 128 protrude from the second face 123 of the wall support 120 to receive the spacer 1 10 and to support the crenulated edge 1 18 of the spacer 1 10.

The channels 128 extend from the surface of the wall support 120 to a greater height than a height of the channels 127a, 127b, 127c. This is to ensure that sufficient support is provided at the major load bearing connection points between the spacer 1 10 and the wall support 120. The channels 127 are configured to engage with the groups of crenulations 1 19 and provide support thereto, although the crenulations 1 19 are not configured to extend through the wall support 120. In alternative embodiments, the crenulations 1 19 can be configured to extend through the wall support 120, to provide additional load bearing connections between the spacer 1 10 and the wall support 120.

Figure 7 illustrates the channels 127 and 128 from a plan view. The slots 130 can be seen opening between the channel side walls 136a, 136b or each channel 128. This plan view illustrates the spatial relationship between the channels 127, 128 and a plurality of arcuate stiffeners 126. The arcuate stiffeners 126 are located symmetrically about the longitudinal axis of the wall support 120, on the second face 123, and namely the inside face of the wall support. In the plan view of Figure 7, the arcuate stiffeners 126 form a series of circular stiffeners 129 that centrally align with the channels 127, 128 along the longitudinal central axis of the wall support 120. These stiffeners 126 extend away from the second face 123 of the wall support

120 and vary in height along their arc. As illustrated in Figure 6, the intersection between the stiffener 126 and the channels 127a, 127c, 128 is at a maximum height of hi . The stiffeners 126 do not intersect with channel 127 b which is located centrally to the circular stiffener 129. The height of the stiffener 126 reduces to h2 at the point where the stiffener 126 is closest to the undulating edge 134. The point at which the arcuate stiffener 126 is furthest from the central axis of the wall support 120 is the zenith, which is the shortest height h2 of each stiffener 126. This variance in the height of stiffener 126 maximises the stiffening effect of the stiffener 126 in the centre of the second face 132, where the spacer 1 10 requires the greatest support and thereby reduces the amount of deformation in the I-beam section of the stud 100 when loaded either as a stud or when attached to a formwork board 142.

Figures 8 and 9 illustrate a perspective view of both the first face 122 and the second face 123 of the wall support 120, respectively. The varying height of the stiffeners 126 can be seen to decrease towards height hi at the edge 134 of the wall support 120 and to increase again to height h2 as the stiffener 126 extends towards the channels 127a, 127c and 128.

The second embodiment of the wall support 220 illustrated in Figure 22, which is designed to assemble with spacers 210, 310, 410, 510 and 610, is quite similar to wall support 120 but rather than having a combination of alternating short channels to support short crenulations and elongate channels to support the elongate crenulations, wall support 220 has a series of elongate channels 228 that correspond with and support the connection crenulations of the spacers of Figures 17 to 21. Arcuate stiffeners 126 are positioned to align with channels 228 to further ensure good support at the load bearing connections between the spacer and the wall supports.

It is within the scope of the presently described wall stud that the elongate channels 228 of the wall support 220 are provided as a single centrally aligned channel spanning the length of the wall support.

The wall support 120, 220 can be formed from a resilient plastic material or composite. In a preferred embodiment the wall support 120, 220 is formed from any one of the following materials; ABS; recycled ABS; Polystyrene; High Impact

Polystyrene (HIPS) plastic or any combination of the above.

Figure 10 illustrates the spacer 1 10 disposed between two identical wall supports 120, prior to joining the three components together to construct the stud 100. Figure 10 further illustrates the necessary alignment between the channels 128 and the extended crenulations 1 14, 1 16. As the wall support 120 is pushed towards the crenulated edge 1 18 of the spacer 1 10, the crenulations 1 19 are partially received within the channels 127a, 127b and 127c to guide and support the connection therebetween. At the same time crenulations 1 19 and channels 127 connect, the extended crenulations 1 14, 1 16 are guided into the channel 128. Crenulations 1 14 and 1 16 are biased in opposing directions and thus pushing them into the channel 128 squeezes the two crenulations together in the plane of the spacer 1 10. The channel 128 is open, thereby providing a passage or slot 130 through the spacer 1 10. As the ridges 104, 106 at the end of the crenulations 1 14, 1 16 pass through the slot 130, the ridges 104, 106 snap in to position over the seat 131 of the slot 130, locking the crenulations 1 14, 1 16 into the slot 130.

This interlocking between the wall support 120 and spacer 1 10 occurs at four, identical locations along the length of the stud 100. There is also a non-paired extended crenulation 1 14, 1 16 on each side, and at each end of the spacer 1 10 to ensure that the ends of the stud 100 are stable and securely connected to a respective wall support 120. The spacer couples to each of the wall supports as a T connection. Figure 1 1 illustrates the fully assembled stud 100.

Illustrated in Figure 12 is an exploded perspective view of the three

components of the stud 100 aligned as in Figure 10, prior to being connected together. A pair of tracks 125 extend longitudinally, the entire length of the second face of the wall support 120. The tracks 125 are centrally located on the wall support 120 and extend from the face 123 by 3mm to 5mm. The tracks 125 provide a physical guide for the joining together of the components of the stud 100. In the embodiment of the stud 100 illustrated in Figure 12, the channels 127 and 128 are integrally formed with the tracks 125. As such the tracks 125 provide a continuous open channel that extends the entire length of the wall support 120 and receives the entire edge 1 18 of the spacer 1 10. The channels 127, 128 extend from the tracks to provide regions of increased support for the upright connection between the spacer 1 10 and the wall support 120. Furthermore, the stiffeners 126 are also integrally formed with the tracks 125 and channels 127, 128 as the entire wall support 120 is injection moulded as a single piece. By integrally forming these features 127, 128, 125 and 126 on the second face 123 of the wall support 120 the features provide strength to each other by providing conjoined load paths across the second face 123 that reinforce one another.

In some embodiments, a series of ridges 1 19a are formed at the ends of the crenulation 1 19 to provide a detent for the crenulations 1 19 when inserted into the channels 127a, 127b and 127c. Cooperating structure (not illustrated in the drawings) can be provided internal to the channels 127a, 127b, 127c to cooperate with the ridges 1 19a and provide an additional locking feature between the wall support 120 and the spacer 1 10.

Figures 13 and 14 provide a before joining and an after joining end view of the stud 100. In Figure 13, two wall supports 120 are position above and below the spacer 1 10. The spacer 1 10 is located centrally to the two wall supports 120, such that the finished cross-section is an I-beam shaped.

From this end view, the bias can be seen on the elongated crenulations 1 14, 1 16. When crenulations 1 14, 1 16 are inserted into the channel 128 each crenulation within the pair is pushed in an opposing direction, respectively providing the necessary resistance to snap-fit the components together within the channel 128.

From the end view of Figure 13 the channel 128 can be seen to extend from the tracks 125. The variance in height between hi and h2 of the stiffener 126 is also clearly illustrated from this perspective. The stiffener 126, in end view, appears triangular in form, with the greatest height hi being immediately adjacent to the channel 128. The height of the stiffener 126 decreasing as the stiffener extends towards the edge 134 of the wall support 120, to a minimum height h2.

Relative to the width of the stud gap, in other words the space between the wall supports, the stiffener has only a shallow protrusion into the space. Each stiffener 126 is not higher than the parallel side walls 136a, 136b of the channel 128, and in terms of the amount of protrusion into the space between the wall supports, the stiffener does not extend through the space from one wall support to the other, but stops short to terminate well before a mid point between the wall supports. Depending on the width of the spacer, the stiffener protrudes less than 50% of the distance between the wall supports, and in the embodiment of Figure 14, less than 25% of the distance.

Accordingly, the stiffeners in an assembly provide very little impediment to concrete flowing between the wall supports. Figure 14 illustrates the stud 100 in its assembled form. The ridges 104, 106 cannot be seen to extend below the first face 122 of the wall support 120. The extended crenulations 1 14, 1 16 also do not extend below the first face 122, such that the outer faces 122 of the stud 100 are smooth and free of projections to provide a clean mating surface to the formwork boards 142.

The structure and geometry of the stud 100 must be sufficient to hold the formwork boards 142 in a fixed position relative to one another. Flexibility or movement in the stud 100 will translate into movement in the formwork boards 142. Thus, excessive flexibility will be detrimental to the finished wall, as the concrete or liquid substrate once poured into the wall formwork 140 will further load the formwork 140 and could deform the formwork that moulds the finished wall.

Figure 15 is a magnified perspective view of the interconnecting features between the wall support 120 and the spacer 1 10. From this perspective the shoulders 107 are illustrated extending from the spacer 1 10 immediately adjacent to each pair of elongated crenulations 1 14, 1 16. These shoulders reduce movement between the wall support 120 and the spacer 1 10 in a longitudinal direction. Once the elongated crenulations 1 14, 1 16 have been received into the slot 130 and the ridges 104, 106 have snap-fitted to the seat 131 the shoulders 107 abut an end face 128a and an end face 128b disposed at opposing ends of the channel 128.

Figure 16 illustrates a stud 100 connected to a pair of formwork boards 142 to form a wall formwork 140. The method of constructing a wall comprises the steps of: (a) constructing a stud 100 by connecting a substantially planar spacer 1 10 between two opposing wall supports 120, the substantially planar spacer 1 10 having a plurality of apertures 1 12 therethrough; and (b) attaching a pair of formwork boards 142 to the two opposing wall supports 120 to form a wall formwork 140. Where the wall to be constructed is a concrete wall, or a similar poured substrate solid wall, the method additionally comprises the steps of: (a) positioning at least one reinforcement bar 145 through one of the plurality of apertures 1 12 within the substantially planar spacer 1 10 of the modular stud 100; and (b) pouring a fluidised substrate into the wall formwork 140 to cure.

The first step of constructing the stud 100 is to select a planar spacer 1 10 of an appropriate width, depending on the thickness of wall to be formed. The choice of planar spacer 1 10 will determine the width of the stud 100 and thereby determine the distance at which the two opposing wall supports 120 will be retained from one another. Standard spacer widths are contemplated to be 100mm, 150 mm and 200mm, however, alternative widths can also be manufactured.

The two wall supports 120 and the spacer 1 10 are longitudinally positioned to align the corresponding channels 127, 128 with the crenulations 1 19 and elongated crenulations 1 14, 1 16, respectively. This alignment is simply achieved by aligning the overall lengths of the three components, such that the first, smooth face 122 of each wall support 120 is facing away from the spacer 110, automatically aligning the channels 127, 128 on the second face 123 of the wall supports 120 inwardly towards the crenulated edges 1 18 of the spacer 1 10. The two wall supports 120 are then pushed towards the spacer 1 10 such that the crenulations 1 19, 1 14, 1 16 snap-fit into the respective channels 127, 128 of each wall support 120.

To construct the wall formwork 140, the first faces 122 of the stud 1 10 are each connected to a pair of formwork boards 142. In a preferred embodiment, an adhesive is applied to each of the first faces 122 before being brought into contact with the boards 142. Where multiple studs 100 are to be used, a first face 122 of each stud 1 10 will be attached to a first board 142 and allowed to cure. Once the adhesive has cured, the unconnected first faces 122 of each stud are coated with further adhesive before introducing a second board 142, to complete the wall formwork 140.

The holes 124 within the wall supports allow for excess adhesive to flow therethrough. Furthermore, when moisture cure polyurethane is being used to adhere the first face 122 of the wall support 120 to a formwork board 142, the holes 124 provide exposure to ambient air to aid in drying and/or curing time. Although the holes 124 have been configured to be circular in this embodiment, they are not limited to a circular form.

When both first sides 122 of each stud 100 are secured to the formwork boards 142, the formwork 140 is transported and oriented in the desired location for the finished wall. The open bottom of the formwork 140a is placed on a floor, platform or base, which will become the foundation for the finished wall. The open top 140b of the formwork remains open to allow for ingress of the liquid substrate.

Once in position at least one reinforcement bar 145 is placed through the aligned apertures 1 12 within the plurality of studs 100. In some embodiments a plurality of reinforcement bars 145 will be selected depending on the size, and strength required from the finished wall. Multiple reinforcement bars 145 can be located through each of the five apertures 1 12 in each of the studs 100. The reinforcement bars 145 are typically manufactured from steel and aid in the reinforcement of the finished wall.

After the predetermined numbers of reinforcement bars 145 are in place, the liquid substrate is delivered to the wall formwork 140, and poured into the open top

The wall formwork 140 is left in place around the substrate as it dries or cures. Once the substrate has cured sufficiently to support its own weight and maintain its own dimensional form, the wall formwork 140 can be removed. Alternatively, the wall formwork 140 can be retained around the wall to provide additional insulation and sound deadening. The studs 100 are retained within the finished wall and are not recoverable. For producing walls of a non-standard height, different lengths of wall support

120 and planar spacer 1 10 can be manufactured. Accordingly, it is contemplated that an additional securing arrangement can be formed upon the free ends of the stud 100. For example, a first free end 102 of the spacer 1 10 can be provided with a channel (not illustrated) and the opposing free end 102 can be provided with a crenulation or tab (not illustrated). In this manner two studs 100 can be joined end-to-end to provide an extended stud 100.

While the above method of constructing a wall formwork is described in relation to the stud embodiment of Figures 1 to 16, the same methodology and techniques can be applied to the embodiments of the spacers and wall support of Figures 17 to 22.

It will be appreciated by persons skilled in the art that numerous variations and modifications may be made to the above-described embodiments, without departing from the scope of the following claims. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A stud for constructing a wall formwork, comprising:

two opposing wall supports; and

a substantially planar spacer having a plurality of apertures therethrough, wherein the spacer is separately connectable to each of the two opposing wall supports such that when the spacer is connected to the pair of opposing wall supports the spacer retains the two opposing wall supports in a fixed, parallel relationship to each other.

2. The stud claimed in claim 1 , wherein the wall supports are configured to couple with the spacer at a connection.

3. The stud claimed in claim 1 or 2, wherein the wall supports have a first coupling and the spacer is configured to have a corresponding second coupling on opposing edges of the spacer.

4. The stud claimed in claim 3, wherein the first coupling on the wall supports are defined by a channel provided on the second surface of each wall support for receiving a longitudinal edge of the spacer.

5. The stud claimed in claim 3 or 4, wherein the second coupling includes crenulations on the opposing longitudinal edges of the spacer.

6. The stud claimed in claim 3 or 4, wherein the second coupling includes detents adjacent opposing longitudinal edges of the spacer.

7. The stud claimed in any one of the preceding claims, wherein adjacent crenulations or detents provided along a longitudinal edge of the spacer extend outward from a plane of the spacer in opposing directions.

8. The stud claimed in any one of the preceding claims, wherein an inside surface of the wall supports comprise stiffeners, the stiffeners extending only part way between the wall supports when assembled.

9. The stud claimed in any one of the preceding claims, comprising apertures within the planar spacer to support a reinforcement bar.

10. The stud claimed in any one of the preceding claims, wherein the spacer is rotationally symmetrical.

1 1 . A method of constructing a wall, the method comprising the steps of:

(a) constructing a stud by connecting a substantially planar spacer between two separate opposing wall supports, the substantially planar spacer having a plurality of apertures therethrough; and

(b) attaching formwork boards to the two opposing wall supports to form a wall formwork.

12. The method claimed in claim 1 1 , additionally comprising the steps of:

(c) positioning at least one reinforcement bar through one of the plurality of apertures within the substantially planar web of the stud; and

(d) pouring concrete into the wall formwork to cure.

13. The method claimed in claim 1 1 or claim 12, including attaching formwork boards to the two opposing wall supports by mechanical and/or adhesive fasteners.