IES64281B2 - Metal lintels - Google Patents

Abstract

A lintel comprises two generally L-shaped pressed sheet metal members 10 and 11 disposed back to back and each comprising a generally horizontal flange 12a, 12b and an upstanding web 13a, 13b. The webs are spaced apart except at the top where at least one of the webs extends towards and is fixed to the other by rivets 17.

Description

METAL LINTELS The present invention relates to lintels and is particularly concerned with lintels formed from metal sheet.

According to the present invention there is provided a lintel comprising two generally L-shaped sheet metal members disposed back to back and each comprising a generally horizontal flange and an upstanding web, the webs being spaced apart except at the top where at least one of the webs extends towards and is fixed to the other.

In preferred embodiments of the invention the L-shaped members are at least approximately mirror images in cross-section, such that the lintel is at least approximately symmetrical about a vertical plane.

In this specification, terms such as horizontal, vertical, upstanding and the like refer to the orientation of the lintel in use.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of a first embodiment of a lintel according to the invention; Figure 2 is a cross-sectional view of a second embodiment of a lintel according to the invention; Figure 3 is a cross-sectional view of a third embodiment of a lintel according to the invention; and Figure 4 is a cross-sectional view of a forth embodiment of a lintel according to the invention. 364281 -2In the Figures, the same reference numerals have been used for the same or equivalent parts of the lintels.

Referring first to figure 1, the lintel there shown comprises two generally L-shaped sheet metal members 10 and 11 disposed back to back. Each member 10, 11 comprises a generally horizontal flange 12a or 12b and an upstanding substantially vertical web 13a or 13b, the webs 13a and 13b being substantially parallel and spaced apart except at the top where the webs extend towards and are fixed to one another. The flange 12a has a first face 12c and a second face 12d. Similarly, the flange 12b has a first face 12c and a second face 12f.

In particular, the tops of the webs include portions 14a or 14b which are inclined towards one another to meet substantially on the centreline of the lintel and, extending vertically from the upper edges of the inclined portion 14a and 14b, further substantially vertical portions 15a and 15b which are fixed together by a series of rivets 16 disposed along the length of the lintel. The rivets 16 are preferably of the self-piercing type. To reduce thermal conduction through the adjoining metal parts 15a and 15b an insulating layer (not shown) serving as a thermal break may be interposed between them prior to rivetting. Such a thermal break material may be polythene or polypropylene.

The two L-shaped members 10 and 11 are made by rolling or pressing metal sheet, such as galvanised steel or stainless steel, and may be made of the same material and to the same sheet thickness. Alternatively, the two L-shaped portions may be of different materials and/or of different thickness to take account the different wall constructions and/or loading characteristics of masonry in the inner and outer leaves of a cavity wall.

In use, the exterior leaf of a cavity wall is supported by the horizontal flange 12a of the L-shaped member 10 while the inner leaf of the cavity wall is supported by the horizontal flange 12b of the L-shaped member 11, the upstanding webs 13a and 13b extending upwardly within the cavity. -3One or more wooden or other suitable material spacer blocks 17 may be interposed between the parallel spaced portions of the webs 13a and 13b. A single such block may extend along the entire length of the lintel or a plurality of spacer blocks 17 may be disposed between the spaced portions of the webs at intervals along the length of the lintel. In the latter case an insulating material such as styrene or plastics foam may be provided in the spaces between adjacent blocks.

Finally, the free outer edge of the flange 12a which supports the exterior leaf of the cavity wall is downwardly and outwardly inclined to act as a lip 18 to shed any water running down the exterior face of the wall.

Turning now to figure 2, the lintel there shown is likewise formed from two back-to-back L-shaped members in the manner described above. The difference is, however, that the portions 14a and 14b of the webs 13a and 13b extend substantially horizontally towards one another rather than, as in figure 1, being inclined. In all other respects the lintel of figure 2 may be the same as that described with respect to figure 1.

In both figures 1 and 2 the L-shaped members 10 and 11 are substantially mirror images in cross-section, such that the lintel is substantially symmetrical about a vertical plane. However, in figure 3 this is not the case, and there is no portion equivalent to the inclined or horizontal portion 14b of figures 1 and 2. The web 13b extends substantially vertically upward to its top edge, where it is met by the upwardly inclined portion 14a of the web 13a and the two there rivetted together. Again, in other respects the lintel of figure 3 may be the same as that described with respect to figure 1.

The embodiment shown in Figure 4 of the drawings is the same as that shown in Figure 1 of the drawings save as follows. There is provided a plate 25 the lower surface 26 of which has a saw tooth shape which provides a key. The plate 25 is u-shaped on either side at 27 and 28. In use, the flange 12a and the flange 12b slidably interengage with the plate -425 so that the faces 12d and 12f rest on the upper face of the plate 25.

When positioned in the desired location on concrete, the saw tooth shape of the lower face 26 provides a key for a more secure positioning of the lintel. Of course, it will be appreciated that a similar arrangement may be used with respect to the embodiments shown in Figure 2 and 3 of the drawings. In addition, it will also be appreciated that other forms of providing a keyed surface may be employed. Thus, the flanges 12a and 12b may be punctured or perforated so as to provide an alternative method of providing a suitable key to assist in the placement of the lintel.

In practice it is proposed to produce a range of lintels as above of the same generic shape, scaling up the thickness of the metal and the dimensions of the lintel cross-section as the span of the lintel is increased, and a range of lintels will be products whose overall lengths correspond to the most regularly used spans of openings in domestic applications.

This will facilitate the selection by non-specialists of the correct lintel for each application, having regard to the span of the opening to be bridged, and the density or the specific weight of the masonry to be supported above the lintel.

Claims (5)

1. A lintel comprising two generally L-shaped sheet metal members disposed back to back and each comprising a generally horizontal flange 5 and an upstanding web, the webs being spaced apart except at the top where at least one of the webs extends towards and is fixed to the other.

2. A lintel as claimed in claim 1, wherein the tops of the webs are fixed together by rivets.

3. A lintel as claimed in claim 1 or 2, wherein an insulating layer is interposed between the tops of the webs where they are fixed together.

4. A lintel as claimed in any one of claims 1 to 3, wherein the L-shaped 15 members are at least approximately mirror images in cross-section, such that the lintel is at least approximately symmetrical about a vertical plane.

5. A lintel substantially as described herein with reference to figure 1, 2 or 3 of the accompanying drawings.