GB2030201A - Lintel - Google Patents

Abstract

A sheet steel lintel comprises an upper flange (11 Figure 1 or 38 Figure 2) and two lower flange portions (6, 13 Figure 1 or 22, 30 Figure 2) interconnected by a box web (5 Figure 1 or 70 Figure 2) of generally diamond section. The web and the flange portion (30) may be reinforced (Figure 2) by stabilizers (40) having a corrugated (42) section. <IMAGE>

Description

SPECIFICATION Lintel This invention relates to lintels.

It has already been proposed to use in domestic buildings lintels made of sheet steel since the latter can readily be factory made and distributed through builders' merchants and other trade channels. Some previously proposed lintels have disadvantages in that they cannot always be readily incorporated into conventional cavity walls and in some instances are relatively costly to manufacture because of their complexity.

According to one aspect of the present invention, there is provided a lintel comprising upper and lower flanges inter-connected by a box web of generally diamond cross-secton so orientated that two opposite portions of the web respectively meet the upper and lower flanges substantially perpendicularly.

According to another aspect ofthe present invention, there is provided a lintel having upper and lower flanges interconnected by a web of oblique parallelogram form in cross-section.

According to a further aspect of the present invention, there is provided a lintel having upper and lower flange portions interconnected by a web of oblique parallelogram form in cross-section, the lintel incorporating reinforcement means operative at the lower flange portion and at a location on the web intermediate the upper and lower flange portions.

Sheet steel lintels embodying the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is an end elevation of a first embodiment of lintel; Figure2 is an end elevation of a second embodiment of a lintel in accordance with the invention; Figure 3 is a fragmentary end elevation of a part of the lintel of Figure 2; and Figure 4 is a cross-section through a cavity wall incorporating lintel in accordance with the embodiment of Figure 2.

The lintel comprises two elements 1 and 2 welded together along two weld seams 3 and 4, parts of the two elements defining a box web defining a cavity 5 of approximately diamond-shape cross-section.

The first element 1 includes a horizontal flange portion 6 intended to be incorporated in one skin 7 of a cavity brick wall and having a downturned end portion 8, a vertical intermediate web portion 9, an inclined intermediate web portion 10 and an upper horizontal flange portion 11 intended to extend into an inner skin 12 of the cavity brick wall. The upper flange portion 11 is of lesser extent than the lower flange portion 6 because the load it will be required to resist is a compression load whereas the lower flange portion 6 is required to resist a tensile load.

The second element 2 includes only a lower horizontal flange portion 13, an upwardly-extending inclined portion 14 forming an acute angle with the horizontal flange portion and an upper, verticallyextending, portion 15 which terminates at the weld seam 4 which joins the upper edge of the portion 15 to the under surface of the horizontally-extending upper flange 11 of the first element 1.

The weld seam 3 lies at a junction between the lower horizontal flange portions 6 and 13 and their respective upwardly extending portions 9 and 14 and together the two lower flanges and the weld seam 3 form a substantially plane surface.

In a modification where higher loads are involved the portions of the lintel defining the diamond shape cavity 5 are extended so that these portions span three brick courses of the cavity wall instead of only two as shown in the drawing.

Although the lintel web has been described as defining a cavity 5 of diamond-shaped cross-section, in more general terms the web can be described as of oblique parallelogram form in cross-section with each pair of adjacent, mutually obtusely-angled sides being defined by a respective one of the elements 1 and 2.

The preferred embodiment of the lintel illustrated in Figure 2 will now be described and will be readily apparent that in the construction of this embodiment three elements are incorporated. One element generally referenced 20 includes a horizontallyextending flange portion 22 with a down-turned free edge portion 24, a vertical web portion 26 extending at right angles to the horizontal portion and an inclined web portion 28 preferably lying at an angle of 150 to the vertical web portion 26.

The right-hand element 29, if necessary of heavier gauge metal than the element 20, includes a horizontally-extending flange portion 30, an inclined web portion 32 preferably extending at an angle of 60" to the horizontal portion, a vertical portion 36 extending upwardly beyond the inclined portion and lying at an angle of 1500 to the inclined portion and finally a terminal horizontal flange portion 38 lying at 90" to the vertical web portion 36.

The third element 40 which is intermittent along the length of the lintel is effectively an unequal angle provided with shallow corrugations 42 spaced along its length and extending as hollow depressions preferably at right angles to the length direction of the lintel. The third component 40 is conveniently termed a "stabilizer" and will be spaced along the length of the lintel at intervals depending upon that length. The stabilizer acts as reinforcement means at the lower flange portion of the right-hand element and at a location intermediate the upper and lower flange portion. For, example, for a lintel having a length of 600 mm two stabilizers will be provided one at each end leaving a space between the stabilizers of 300 mm. Each stabilizer has a length of 100 mm.

The three elements at sections of the lintel as a whole where the three elements are incorporated are provided with welds 44, 46 respectively at the upper end of the left-hand element where it abuts the inside of the corner joining the edge portion 38 of the right-hand element and the vertical portion 36 thereof, and at the abutment between the junctions of the horizontal flange portion 22 and vertical flange portion 26 of the left-hand element on the one hand and the horizontal portion 30 and the inclined portion 32 of the right-hand element 29 on the other hand.The stabilizers 40 are welded to the junction of the portions 32, 36 with a continuous fillet weld 48 at the upper end 41 of each stabilizer and by means of tack welds 50 at the corrugations 42 and at the sides 52 thereof, to the flange portion 30, the tack welds ensuring that during galvanizing and subsequently, the galvanizing fluid has free access and free drainage paths.

The main welds 44, 46 i.e. those not involving the stabilizers are preferably 50 mm in length and the number will vary according to the length of the lintel being produced.

Referring now to Figure 4, two brick wall skins 60, 62 are shown, the upper three courses 64,66 being shown in section while the lower courses are shown as end elevations since, as is customary, the lintel spans a gap in the brick wall. As will be apparent the horizontal flange portions 22,30 of each of the main elements of the lintel lie in mortar of two pairs of courses lying opposite one another in each of the two skins. The diamond section cavity portion 70 of the lintel lies in the cavity between the skins.

As for the first embodiment, keying of paster or other material is ensured by means of expanded metal 72 tack welded at approximately 200 mm centres along the edges of the horizontal portion 30 of the right-hand element of the lintel.

The second embodiment may be modified so that the box web 70 has a greater vertical extent, for example so that its extends over three brick courses.

In such modifications it may be desirable under certain conditions to weld an additional plate to the lower face of the flange portion 30, such plate being corrugated in the same manner as the third element 40, the corrugations extending transversely to the length direction of the lintel. This plate extends substantially across the width of the flange portion and is secured thereto by tack welds at the ends of the crests of the corrugations and along the sides of the plate.

In either the second embodiment or in the modification, holes may be drilled through the third element 40 at the junction of the two limbs and certain of the corrugations for example every other corrugation. These holes may be 3/8 inch diameter and will be filled with weld metal which passes through and becomes welded to the upper surface of the flange portion 30. The provision of such rigidity and additional strength is necessary only under certain arduous conditions.

In all embodiments one portion at least of the box web meets the upper flange portion substantially at right angles and similarly one portion at least (not necessarily the same portion) meets the lower flange substantially at right angles.

The embodiments hereinbefore described and the modification thereof have a configuration such that the neutral axis is as near central as possible without having a symmetrical section, to obtain greatest Moment of Inertia and Section Modulus from relatively light gauge material with consequent reduced manufacturing and transport costs, while still enabling the lintel to withstand high bending loads.

The lintel sections described avoid the use of lapped joints which can be harmful where, as will generally be the case, the lintel is made of steel sheet, the risk being otherwise present that galvanizing fluids will be trapped between the layers of the iapped joint when galvanising is carried out after fabrication.

Finally, the lower plane surface of each lintel is effectively continuous and where necessary it is readily possible to provide effective keying apertures for plaster or alternatively for the support of an expanded metal mesh which will itself provide a key for plaster.

Claims (17)

1. Lintel comprising upper and lowerflanges interconnected by a box web of generally diamond cross-section so orientated that two opposite portions of the web respectively meet the upper and lower flanges substantially perpendicularly.

2. A lintel according to Claim 1, in which the lower flange extends on both sides of its junction with the box web whereas the upper flange extends only on one side of its junction with the box web.

3. A lintel according to Claim 2, formed of two shaped elements welded together, one said element forming the upper flange, two adjacent sides of the web which together extend between the upper and lower flanges, and that portion of the lower flange which extends on the side of the web opposite to the upper flange, the other said element forming the remainder of the lower flange and the other two adjacent sides of the web, and the two elements being joined by weld seams at the junctions of the box web with the flanges.

4. A lintel according to Claim 3, in which the said elements are of sheet steel, and the lintel has been galvanized after fabrication from the elements.

5. A lintel according to any one of Claims 2 to 4, in which the lower flange extends a greater distance from the web on the side opposite the upper flange than the upper flange extends from the web.

6. A lintel according to any one of Claims 2 to 5, in which the edge portion of the lower flange, on the side of the web opposite the upper flange, is turned down.

7. A lintel having upper and lowerflanges interconnected by a web of oblique parallelogram form in cross-section.

8. A lintel according to Claim 7, fabricated from two sheet elements with each pair of adjacent, mutually-obliquely-angled sides of the web being formed by a respective one of said sheet elements.

9. A lintel having upper and lower flange portions interconnected by a web of oblique parallelogram form in cross-secton, the lintel incorporating reinforcement means operative at the lower flange portion and at a location on the web intermediate the upper and lower flange portions.

10. A lintel according to Claim 9, comprising two main elements one of which defines one lower flange portion and two sides of the web parallelogram and the other of which elements defines another lower flange portion, the other two sides of the web parallelogram and the upper flange portion, the reinforcement means being operative at the lower flange portion of the other of said elements and at the junction between said other two sides of the web parallelogram.

11. A lintel according to Claim 9 or Claim 10, wherein the reinforcement means is an angle section member.

12. A lintel according to Claim 9 or Claim 10 wherein the reinforcement means is a plurality of angle section members spaced lengthwise of the lintel.

13. A lintel according to Claim 11 or Claim 12, wherein the or each angle section member has corrugations extending at an angle to the length of the lintel, the angle section member being welded to the associated flange portion at the crests of the corrugations.

14. A lintel according to any one of Claims 9 to 13 wherein the upper flange portion extends in only one direction away from the upper end of the web.

15. A lintel according to any one of Claims 10 to 14, wherein the main elements are of different gauge sheet metal, the reinforced element being of heavier gauge than the non-reinforced element.

16. A lintel according to any one of Claims 10 to 14, wherein the main elements are welded together by intermittent weld seams at the junction between the web and the upper flange portion and at the junction between the web and the lower flange portion.

17. A lintel substantially as hereinbefore described with reference to any one of Figures 1,2 or 3 of the accompanying drawings.