GB2026068A

GB2026068A - Load-bearing component

Info

Publication number: GB2026068A
Application number: GB7923179A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-07-19
Filing date: 1979-07-03
Publication date: 1980-01-30
Also published as: GB2026068B

Abstract

In order to provide e.g. keying zones on a load-bearing component, the material of the zone is slit and loops 3 of material are deformed out of the plane of the component, providing gaps 4, for example through which plaster can pass and provide a key. <IMAGE>

Description

SPECIFICATION Load-bearing component Background of the Invention The present invention was conceived in general in relation to the provision of at least one keying zone on an integral sheet material part of a load-bearing component, so that plaster can be applied directly to said part, but the zone so formed has been discovered to have more general applicability. The component may in particular be a structural building component such as a lintel or a bearing beam, but other possible components to which the invention may be applied are for instance anchor plates (metal floor tiles), cable trays, cable tray supports, cable ladders, racking and shelving; anchor plates must normally be keyed to underlying concrete and the other components have holes for retaining clips or straps for cables etc.The component is loadbearing, e.g. in the sense that it must be capable of bearing loads over and above that of the plaster itself, i.e. excluding expanded metal applied to another component purely for keying plaster.

It has been possible to provide direct keying zones in the outer face of said part by punching holes in the part. However, the holes weaken the part, and, in addition, the plaster tends to extrude straight through the holes and not sideways, so that the keying is often imperfect.

In practice, keying has been provided on lintels or beams by fixing to the building components a further non-structural keying layer, usually made of expanded metal. This further layer provides good keying, and does not weaken the building component, but increases material and fabrication costs, and also increases weight.

The Invention The present invention provides a component as set forth in Claim 1.

Using the invention when the material is sheet metal, the zone can be provided by a simple punching operation, and there is no removal of metal. It is believed that there may be some weakening of the sheet metal, but this weakening is not excessive and, depending on the type of metal used, the distortion of the deformed part can compensate for the weakening effect by increasing the strength of the deformed part itself. Even if a punching operation is not performed, for instance in the case of keying zones moulded in plastic, the provision of the keying does not excessively reduce the strength of the sheet plastic.The invention is particularly useful when, in accordance with Claim 13, the component is for supporting a load in the plane of said part, and the invention can avoid weakening said part with respect to such a load, or can even increase the strength of said part with respect to such a load.

As the plaster, cement, or other deformable substance, when passing through the gap which is formed in accordance with the invention, must pass in a direction parallel to the face of said part, secure keying is provided.

It is also found that if plaster is being applied and there is a cavity behind said part, the protuberances on the material and the projection of small amounts of plaster reduce air flow which wipes up against the rear face of said part, and this can provide marginally better insulation or "U" values. Claims 2 to 1 7 claim optional features of the invention.

Brief Description of the Drawings The invention will be further described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a schematic, vertical section through a typical sheet metal lintel; Figure 2 is a view, on a larger scale, looking in the direction II indicated in Fig. 1; Figure 3 is a vertical section along the line Ill-Ill of Fig. 2; and Figure 4 is an isometric view of part of a sheet metal cable tray.

Description of two Embodiments of the Invention Fig. 1 shows a sheet-metal lintel designed for bridging an opening in a two-skin outer wall of a building, and is of box shape and formed of rolled or pressed sheet steel components which are welded together. The inner wall 1 of the lintel is a part of the lintel whose front face is to be plastered, and this part supports a vertical load in its own plane.

The inner wall 1 is shown in detail in Figs.

2 and 3, and it will be seen that its front face is provided with a plurality of keying zones each comprising two slits 2 each of which has a substantially straight central portion and curved end portions which curve inwards and away from the side of the slit 2 on which there is undistorted metal. The major portions are parallel to one another, and the metal between the slits 2 has been displaced back out of the general plane of the front face of the inner wall 1 to form a shallow loop 3 (see Fig. 3). The ends of the loop 3 are attached to the remainder of the metal of the inner wall 1 in that the ends of the slits 2 are separated from each other by portions of unslit metal. In this manner, a gap 4 (see Fig. 3) is provided, through which plaster can pass behind the front face of the inner wall 1 and provide a key.The preferred maximum width of the gap (as seen in Fig. 3) is from 3 to 7 millimetres, a suitable gap being about 3.5 millimetres.

The steel may be about 2 millimetres thick.

As can be seen in Fig. 2, the keying zones are in a geometric pattern, and the distribution of the keying zones is such that in the two directions of 45" to the horizontal (i.e.

two directions at right angles to each other), the slits 2 of alternate zones extend alternatively in the direction of the vertical load on the lintel and at right angles to the direction of the vertical load on the lintel. This is done to give the best load bearing charcteristics for the inner wall 1. The pattern is in accordance with Claims 9 to 11, and each zone is identical.

In practice, the slits 2 can be formed as simple cuts, and the loops 3 pressed out using a punching tool. It is found that a punching tool in the form of a large half-angle wedge is the most satisfactory, the shape of the loop 3 being as shown in Fig. 3. However, as an alternative, the punching tool could have a curved, e.g. part-circular, section operative face.

As an alternative to the specific shape of keying zone as shown in Fig. 2, the keying zone may be as set forth in Claim 7, the slits themselves having the same shape as in Fig.

2.

The plaster can be applied in the normal manner, firstly applying a rather thick backing coat, of relatively dry consistency, and then applying a thinner, rather wetter surface coat.

Fig. 4 shows a sheet-metal cable tray having a conventional shape, but provided with keying zones, exactly as described above, on the side walls and on the base. The top row of keying zones on the side walls is shown as being that having the vertical slits, but it could alternatively be that having the horizontal slits.

It will be noted that the loops 3 of the keying zones can be used for securing cables in the trays, using plastic clips.

An anchor plate (not illustrated) can have the construction shown in Figs. 2 and 3, the loops 3 being on the underside and grouted in concrete when laying the anchor plate.

Claims

1. A load bearing component comprising an integral part made of sheet material whose outer face is provided with at least one zone in which the material has a slit penetrating right through from one face to the other and the inner face of the material on one side of the slit is to the outside of the outer face of the material on the other side of the slit, thereby providing a gap through which a deformable substance can pass and provide a key.

2. The component of Claim 1, wherein the material on a first side of the slit remains substantially undistorted and the slit has a substantially straight central portion and curved end portions curving away from the first side of the slit.

3. The component of either of the preceding Claims, wherein the material on a first side of the slit remains substantially in the plane of the front face of said part, and the material on the other side of the slit is behind the front face of said part.

4. The component of any one of the preceding Claims, wherein said zone has at least two slits whose major portions are parallel to one another, the material between the slits not lying in the general plane of the outer face of said part.

5. The component of Claim 4, wherein said zone has only two slits, whose major portions are parallel to one another, the material between the slits forming a shallow loop.

6. The component of any one of Claims 1 to 3, wherein said zone has a portion of material which does not lie in the general plane of the outer face of said part, and which is delineated by at least two said slits whose ends are separated from each other by portions of unslit material.

7. The component of Claim 6, wherein said zone has a first part of slits whose major portions are parallel, and a second pair of slits whose major portions are parallel but at right angles to those of the first pair of slits, the slits forming a square shape and ends of the slits being separated from each other by portions of unslit material.

8. The component of any one of the preceding Claims, in which the outer face of said part is provided with a plurality of substantially identical said zones in a geometric pattern.

9. The component of Claim 5, wherein the outer face of said part is provided with a plurality of said zones in a geometric pattern in which the zones are equispaced rows, the slit major portions in alternate rows extending parallel to and at right angles to the rows, respectively, said zones of each row being aligned in the direction at right angles to the row, with said zones of the next row but one, and said zones of alternate rows being staggered so that the centres of said zones of each row are spaced half way between the centres of said zones of the next row.

10. The component of Claim 9, wherein the distance between the slit of one said zone and the nearer slit of the nearer said zone in the same row is greater than the length of the slits.

11. The component of Claim 9 or 10, wherein the distance between the centres of adjacent said zones in any one row is substantially equal to the distance between the centres of the closest said zones which are in two respective rows separated by one row.

1 2. The component of any one of the preceding Claims, wherein the material of said part is sheet metal and the, or each, slit is a cut made in the metal.

1 3. The component of any one of the preceding Claims, wherein the component is for supporting a load in the plane of said part.

14. The component of Claim 13, wherein the front face of said part is provided with a plurality of said zones, said slits having major portions which are substantially straight, and the distribution of said zones being such that, in at least two directions at right angles to each other, the slits of alternate zones extent alternatively in the direction of said loads and at right angles to the direction of said loads.

1 5. The component of any one of the preceding Claims, and being a lintel.

1 6. The component of any one of Claims 1 to 14 and being a cable tray.

1 7. The component of any one of Claims 1 to 12, and being an anchor plate.

18. A load-bearing component, substantially as herein described with reference to, and as shown in, Figs. 1 to 3 of the accompanying drawings.

1 9. A load-bearing component, substantially as herein described with reference to, and as shown in, Fig. 4 of the accompanying drawings.

20. The component of any one of Claims 1 to 1 3 and 15, with a layer of plaster on the front face of said part and held thereon by the said zone(s).