CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from South African patent application number 2021/07020 filed on 21 September 2021 , which is incorporated by reference herein.

FIELD OF THE INVENTION

This invention relates to a support for mesh made from reinforcing bar (“rebar”) or wire.

BACKGROUND TO THE INVENTION

Meshes made from either reinforcing bar, also known as rebar, or wire are widely used in the construction industry to provide reinforcement in concrete structures. Typically shuttering is erected to form a temporary mould for concrete to be cast therein. The mesh is located between the sides of the shuttering so as to be encased by the concrete. So, for example, with horizontal floor slabs, the mesh is supported above the bottom of the shuttering.

Meshes are well-known and have a plurality of mesh elements which cross to form a regular network pattern or are formed by expanding material such as metal sheets.

The term “mesh” will be understood to refer broadly to any mesh. Without limiting the generality of its meaning, the term will be understood to mean any mesh that is suitable for reinforcing concrete, or for increasing its tensile or flexural strength, or for spreading loads on concrete over a greater area, or for resisting breaking apart or deterioration of concrete, among other applications. Without limitation, the term will be understood to mean any mesh formed from reinforcement elements welded together, tied together or otherwise fastened together or integrally formed with one another, including but not limited to reinforcing bars or wires welded together, tied together, or fastened together. Without limitation, the term will be understood to mean a reinforcing mesh, wire mesh, reinforcing welded rib mesh, welded wire mesh, slab mesh, or trench mesh. It may be understood to mean, without limitation, a welded reinforcement mesh or a conventionally placed reinforcement mesh made from tying reinforcement elements together. Also without limitation, it may mean any mesh arrangement that is suitable for positioning in upper, lower or central regions of a concrete slab or other concrete component.

Similarly, the term “mesh element” will be understood to refer broadly to any element suitable for forming a mesh as understood herein, including but not limited to a reinforcement element. Without limitation thereto, a reinforcement element may comprise a reinforcing bar or wire suitable for reinforcing concrete.

Numerous sacrificial devices exist for supporting a mesh above shuttering. These are sometimes referred to as rebar support chairs, metal horse stools, support chairs, post-tension chairs and reinforcing steel bar stools. These have a three-dimensional structure and are moulded from metal or plastics material, or formed from stiff, wire-like elements which are secured together, typically by welding.

Although these devices are generally effective, they tend to be relatively expensive, especially where large numbers are needed to support a mesh. Also, their three-dimensional shape makes them rather inconvenient to transport in bulk due to the volume they occupy.

Often, for either or both of these reasons, bricks are simply used to support the mesh. This is undesirable for a number of reasons, including the relatively large volume in the concrete occupied by the bricks and that the bricks are seldom of the correct height required for the correct support. Bricks are also technically unacceptable as they do not match the design strength of the floor itself, which creates localized areas of reduced strength or integrity of the concrete slab or floor.

The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge in the art as at the priority date of the application.

SUMMARY OF THE INVENTION

In accordance with an aspect of the invention there is provided a support for a mesh having a plurality of mesh elements, the support comprising a self-supporting structure having a top edge and a bottom edge, the top edge shaped to receive a mesh element to support its weight in use, and wherein the structure is formed by bending an elongate sheet of material.

The support may also have the capacity for supporting a live load.

The top edge may have a series or plurality of indentations or recesses therein, at least some indentations shaped to receive a mesh element. The self-supporting structure may be tubular or generally channel sectioned. A tubular structure may have any suitable shape in cross-section, including a circular, square or multi-sided crosssection. A channel-sectioned structure may have any suitable shape, including a regular, trapezoidal or multilateral shape, in which the ends of the sheet of material are spaced apart.

The series of indentations may have a sinuous or undulating shape, or each indentation may be angular, such as square, serrated or toothed in profile. In use, a mesh element may be received in a pair of diametrically opposite indentations. Receiving a mesh element in an indentation may assist in preventing the support moving out of position or toppling if the mesh is moved or when concrete is, for example, cast or poured over the mesh in use, or live load. The sheet may be made of a stiff, flexible material such that the tube resists collapsing under axially directed pressure or weight from the mesh. The sheet may be made from a metal, including zincaluminium.

The ends of the sheet may be secured together when forming the tube. The bottom edge of the structure may include tabs which can, in use, be folded outwardly to provide stabilising feet. The tabs may operatively assist in preventing the structure toppling sideways.

The tabs may be defined between slits or lines of weakness in the elongate sheet of material.

Tongues may be provided in the sheet which are shaped to engage with complementary slots in the sheet to operatively secure the ends of the sheet together to form a tube.

There is further provided a material blank configured to be operatively bendable into a self- supporting structure to provide a support for a mesh, the structure having a top edge shaped to receive a mesh element and spaced apart from a bottom edge and the structure capable of supporting the weight of the mesh in use, the blank having a generally elongate shape with opposite elongate edges and opposite ends, one elongate edge operatively forming the top edge.

The top edge may have a series of indentations therein.

The self-supporting structure may be tubular or generally channel sectioned. A tubular structure may have any suitable shape in cross-section, including a circular, square or multi-sided crosssection. A channel-sectioned structure may have any suitable shape, including a regular, trapezoidal or multilateral shape, in which the ends of the sheet of material are spaced apart. Securing formations may be provided at or near the ends to operatively enable the ends to be secured together to form a tubular structure.

The support formed is configured to support a mesh without folding, buckling, or collapsing under the weight of the mesh. The blank is formed from a sheet of stiff, flexible material and may have a generally rectangular shape The material may be a metal, including zinc-aluminium. With the ends of the blank operatively secured together, a tube may be formed.

The ends of the blank may be secured together in an overlapping fashion. The securing formations may include at least one, preferably more than one, tongue and slot which operatively engage.

A series of slits or lines of weakness may be provided in the elongate edge opposite the top edge, the slits or lines of weakness extending in the direction of the top edge and defining between them tabs. The tabs may, in use, be folded outwardly to provide stabilising feet to the structure.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

Figure 1 is a top plan view of a blank used in forming a support;

Figure 2 is a three-dimensional view of a support for a reinforcing mesh;

Figure 3 is a first side view of the support of Figure 2;

Figure 4 is a second side view of the support of Figure 2;

Figure 5 is a third side view of the support of Figure 2;

Figure 6 is a fourth side view of the support of Figure 2;

Figure 7 is a bottom, perspective view of the support of Figure 2; Figure 8 is a top view of the support of Figure 2;

Figure 9 is a bottom view of the support of Figure 2;

Figure 10 is a perspective view of a support in use, supporting reinforcing mesh;

Figure 11 is a perspective view of multiple supports in use together, supporting reinforcing mesh; and

Figure 12 is a side view of two supports in use between shutter board and reinforcing mesh.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

There is provided a support for a mesh having a plurality of mesh elements, the support including a self-supporting structure with a top edge spaced apart a determined distance from a bottom edge and formed by folding or bending an elongate sheet of material. The determined distance may be the height a mesh is desired to be supported above a surface, such as a shutter board. The top edge is shaped to receive a mesh element to support its weight in use such that the mesh is supported the determined distance above the surface.

A self-supporting structure is one which stands without external aid. The structure may stand in a generally upright condition in which the sheet of material operatively extends in a generally upright condition between the bottom edge and the top edge.

The self-supporting structure may be tubular or generally channel sectioned. A tubular structure may have any suitable shape in cross-section, including a circular, square or multi-sided crosssection. A channel-sectioned structure, or an open-ended structure, may have any suitable shape, including a regular, trapezoidal or multilateral shape, in which the ends of the sheet of material are spaced apart.

Where the structure is tubular, the ends of the sheet may be secured together, but embodiments may be provided in which they are not secured together.

The top edge of the structure may have a series or plurality of indentations therein, at least some indentations, preferably all of them, being shaped to receive a mesh element. The cross-sectional shape of the structure may change from the top edge to the bottom edge.

The series of indentations may have a sinuous or undulating shape, or each indentation may be angular, such as square or triangular, serrated or toothed in profile. In use, a mesh element may be received in a pair of diametrically opposite indentations. Receiving a mesh element in an indentation may assist in preventing the support moving out of position or toppling if the mesh is moved or when concrete is, for example, poured over the mesh in use. The sheet may be made of a stiff, flexible material such that the structure resists collapsing under axially directed pressure or weight from the mesh, in other words to counteract buckling under the weight of the mesh or concrete. The sheet may be made out of a metal, including zinc-aluminium.

The bottom edge of the structure may include tabs which can, in use, be folded outwardly to provide stabilising feet. These may operatively assist in preventing the tube toppling sideways.

When folded outwardly, the tabs may provide stabilising feet which extend generally normally, or radially, to the structure. Where the structure forms a tube, the stabilising feet may result in the tube having a multi-sided cross-section near the bottom of the tube, while the tube has a generally circular cross-section near the top.

The tabs may be defined between slits or lines of weakness in the elongate sheet of material.

Tongues may be provided in the sheet which are shaped to engage with complementary slots in the sheet to operatively secure the ends of the sheet together to form the tube.

A material blank for a self-supporting structure is also provided. The blank is configured to be operatively bendable or foldable into a self-supporting structure to form a support for a mesh, the structure having a top edge spaced apart from a bottom edge. The support formed is configured, through selection of material and shape, to support a mesh without folding, buckling, or collapsing under the weight of the mesh.

The self-supporting structure may be tubular or generally channel sectioned. A tubular structure may have any suitable shape in cross-section, including a circular, square or multi-sided crosssection. A channel-sectioned structure may have any suitable shape, including a regular, trapezoidal or multilateral shape, in which the ends of the sheet of material are spaced apart.

The blank may have a generally elongate shape with opposite elongate edges and opposite ends. One elongate edge operatively forms a top edge. The top edge has a series of indentations therein. The indentation may have any suitable shape, including a sinuous shape, or an angular shape, such as square or triangular, in profile.

The elongate edge opposite the top edge of the blank may have a series of slits or lines of weakness therein extending in the direction of the top edge and defining between them tabs. The tabs may, in use, be folded outwardly to provide stabilising feet to the tube.

Securing formations may be provided at or near the ends to operatively enable the ends to be secured together. With the ends of the blank operatively secured together, a tube may be formed.

The blank is formed from a sheet of stiff, flexible material and may have a generally rectangular shape. The material may be a metal, including zinc-aluminium.

The ends of the blank may be secured together in an overlapping fashion. The securing formations may include at least one, preferably more than one, tongue and slot which operatively engage.

An embodiment of a blank (1) is shown in Figure 1. The blank (1) is, in this embodiment, stamped from a roll of 0.5 mm zinc-aluminium metal sheet, and has an elongate, generally rectangular shape. The blank (1) has a pair of opposite elongate edges (3, 5) and a pair of opposite ends (7, 9).

One of the elongate edges (3) forms an operatively top edge. The top edge (3) has a series of indentations (11) which, in this embodiment, are sinuous or wave-like and extend the length to the edge (3). It will be appreciated that other types of indentations may be used, for example giving the top edge (3) a serrated profile or an undulating shape.

A series of equally spaced slits (13) extend normally from the edge (5) in the direction of the top edge (3) about a third of the way along the height of the blank (1). Tabs (15) are defined between the slits (13). An inwardly extending shoulder (17) is provided in the lower edge (5) extending from the end (7) the distance of a tab (15) and the height of a slit (13). The reason for this shoulder (17) will become apparent later.

A pair of spaced apart tongues (21) extend normally from the end (7). Corresponding notches (22) extend into the opposite end (9). These may result merely from the continuous stamping process in which the blanks are contiguous. A pair of slots (23) complementary to the tongues (21) is provided spaced apart from the end (9) and aligned with the first slit (13) adjacent that end. A further, internal tongue (27) is defined by an arch-shaped slot (29) generally adjacent the uppermost tongue (21). A complementary slot or window (31) is provided in the opposite end (9) adjacent the uppermost notch (22).

Oblong openings (35) are formed in the blank (1) to save weight and material, each central to a respective tab (15) and aligned with the tongues (21). The openings (35) also allow concrete to flow through and fill the internal space of the mesh support in use.

The blank (1) is formed into a tube (50) to form a support is shown in Figures 2 to 9. As shown in Figure 2, the tabs (15) are folded outwardly to extend generally normally or at right angles to the blank (1).

Referring to Figures 2 and 3, the blank (1) is bent or folded in its length to form a tubular shape. The ends (7, 9) are overlapped, and the tongues (21) inserted into the slots (23). Once inserted, the tongues (21) can be bent back to prevent them from dislodging and in so doing the tongues (21) facilitate holding the tube together. Furthermore, in this position, the tongue (27) is adjacent the slot or window (31) and is bent inwardly to extend through the window (31), as shown more clearly in Figure 2, and then further downwardly to lie adjacent to the side of the blank (1). In this condition it also captures the ends (7, 9) together.

It will be understood that the tube (50) so formed will have a generally circular cross-section at its upper end (3) and generally hexagonal cross-section at its lower end as a result of the tabs (15) having been bent outwardly.

The tabs (15) in this operative condition act as feet to stabilise the tube (50) as prevent it toppling sideways. In this tubular condition the tab (15) adjacent the end (9) extends through the shoulder (17).

The tube (50) provides a support having a top edge (3) with a series of indentations therein and a bottom edge (52) with tabs (15) which extend radially outwardly therefrom. It will be appreciated that the bottom edge (52) is at the level at which the tabs (15) extend from the tube (50).

In use, a plurality of tubes (50) are arranged on a shutter board (60) and a reinforcing mesh (62) is then simply placed onto the tubes (50), as shown in Figures 11 and 12. Each tube (50) provides a self-supporting structure with a top edge (3) spaced apart a determined distance from a bottom edge (52) and supports the mesh (62) substantially the determined distance above the shutter board (60).

The indentations (11) are shaped to receive at least one of the elements that form the mesh and in so doing prevent excessive lateral movement of the support (50) during placement of the mesh (62) and also during casting of the concrete (not shown).

As indicated previously, the feet provided by the tabs (15) assist in providing stability to the support (50), in particular against toppling sideways after positioning and during placement of the mesh (62).

Concrete is easily able to fill the support tube (50) in use, and this process is also assisted by the openings (35) which allow the concrete to flow through and fill the internal space of the mesh support.

A strong, low volume support for a mesh is thus provided which does not affect the structural integrity of the slab (not shown) of which it forms an integral part. The support also has the capacity for supporting a live load.

Being a simple metal pressing it is both relatively cheap and easy to manufacture. A further advantage is provided by the use of blanks to form the support. Blanks can be easy stacked and transported and are thus volumetrically more efficient to transport than tubular supports or supports of other three-dimensional shapes.

It will be appreciated that the blanks could be formed from any suitable material. Where zincaluminium is used it could have a thickness in a range between 0.27mm to 0.55mm. Also, the blank can have any suitable configuration. For example, the indentations need not be sinuous but could have a castellated or angular shape. Also, where the tube is to be formed, the ends can be secured together in any suitable manner, and not necessarily using the tongue and slot configuration described. For example, the securing formations at the ends of the sheet may be a plurality of loop formations or knuckles (similar to a door hinge) that may be secured to one another, such as by way of a connecting pin. Alternatively, hooks and catches may be provided as securing formations to secure the ends of the sheet together in use.

It may be possible to provide a tube with suitable structural integrity without securing the ends of the blank together. For example, the material may be bent to have a triangular or other suitable shaped cross-section with the ends merely in proximity to each other. It may also be possible to avoid the use of stabilising feet depending on the diameter of the tube and its configuration. It may, for example, have a frusto-conical shape with a relatively wide base.

It will be apparent that the support can be made to provide any suitable determined distance between its top edge and bottom edge by adjusting the height of the blank.

Also, it may be possible to provide sulcations or fold lines to assist in bending the blank into a more angular cross-sectioned tube, for example triangular, square, polygonal, or hexagonal.

The foregoing description has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure.

The language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.

Finally, throughout the specification and accompanying claims, unless the context requires otherwise, the word ‘comprise’ or variations such as ‘comprises’ or ‘comprising’ will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.