GB2162878A - Lintels - Google Patents

Abstract

A lintel is made from two steel sheets 10, 12 each providing a horizontal flange 18, 30 for supporting outer and inner skins of a wall. From the flanges extend upright walls 20, 32 defining a downward opening channel. The upper portions 22, 34, 36 of the walls 20, 32 are formed and welded to each other to provide a box section. Wooden blocks 42 may be provided in the channel mouth, and a layer of mesh 52 secured to the blocks and the inner flange 30 to provide a key for plaster. This construction provides high rigidity with minimum use of steel, and avoids having a welded joint exposed to the weather. <IMAGE>

Description

SPECIFICATION improvements in lintels This invention relates to improvements in lintels.

It is known to provide a lintel fabricated from one piece of metal and consisting of a downwardly-opening channel for insertion into the cavity of a cavity wall over an opening, and provided with horizontal flanges to support the inner and outer-skins of the wall. A block of wood may be inserted within the downwardly opening channel, wire mesh being attached to the undersides of the horizontal flange supporting the inner skin and to the wooden block. This has the disadvantage that the downwardly-opening channel has to be of considerable height to achieve the required degree of rigidity.

It is-also known to provide a lintel fabricated from three pieces of steel. A first piece having lazy Z form and providing upper and lower flanges to support the skins and a sloping wall in between, a second piece being welded as an extension of the lower flange -below the upper flange. and a third piece joining that extension to the upper flange, thereby providing a box section. This has the disadvantages that there is one welded joint exposed to the weather, and a relatively large amount of metal is used.

According to the present invention there is provided a lintel comprising a downwardlyopening channel and a pair of mutually oppositely directed flanges at the lower edges of the channel for supporting respectively inner and outer skins of a cavity wall, the upper portion of the channel being formed with a longitudinally extending box section.

Optionally, one or more, but not all, of the walls of the box section may be intermittent (i.e. interrupted by gaps).

Preferably the lintel is formed from two sheets of steel bent to shape and welded together, each sheet providing one said flange and an upright wall of the channel, and optionally part of the box section. Suitably one of the sheets has an upwardly sloping panel extension at the upper edge of its respective upright wall of the channel, and the other sheet has a downwardly sloping panel extension at the upper edge of its respective upright wall of the channel.

In a preferred construction, the -upright wall of one said sheet, or an extension thereof, is welded to the upright wall of said other sheet, and the upper edge portion of the upright wall of said other sheet is bent over and welded so as to form said box section. Preferably said upper edge portion is welded to the upright wall, or an extension thereof, of said one sheet thereby forming said box section.

The two pieces of sheet steel may be of differing gauges according to the varying requirements for the inner and outer parts of the lintel.

A wooden block may be provided held within the upright walls of the downwardlyopening channel and a layer of wire mesh attached to said wooden block and the horizontal flange supporting the inner skin.

In a preferred method of construction, the lintel is fabricated from black mild steel sheet welded together and subsequently galvanized.

The lintel preferably has as many of its angles as possible made the same so that the same tool and press setting may be used for each of them.

Various embodiments of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a side view of a first embodiment of lintel; Figure 2 is a side view- of the lintel of Fig. 1 in use; Figure 3 is a side view of a second embodiment of lintel; Figure 4 is a fragmentary perspective view of part of a third embodiment of the lintel; and Figure 5 is a fragmwntary perspective view of the embodiment of Fig. 4.

Referring to Fig. 1; this shows a lintel comprising a first member 10 suitably fabricated from mild steel sheet and a second member 1 2 similarly fabricated. The first member has a right-angled bend 14 and an obtuse-angled bend 1 6 thus giving a horizontal flange 18 an upstanding wall 20 and upwardly inclined panel 22. The member 1 2 has a right-angled bend 24, an acute-angled bend 26 and a right-angled bend 28, thus giving a horizontal flange 30, an upstanding wall 32, and an upper edge portion comprising a downwardly inclined panel 34 and a reentrant panel 36.

The inclined panel 22 has its edge 38 welded to the upright wall 32 of the member 1 2 and the re-entrant panel 36 has its edge 40 welded to the inclined panel 22 of the member 10, thereby forming a box section which serves to add rigidity to the lintel as a whole. The members 10 and 1 2 can be fabricated from different gauges of sheet metal according to the properties which they are desired to display, (e.g. the inner member 1 2 being of thicker gauge than the outer member 10), but they are preferably to be made from the same metal to avoid problems with corrosion.

The walls 20 and 32 form a downwardlyopening channel in which a block 42 of wood or other similar material is received. This may be dimensioned so as to extend as far as the bend 1 6 of the member 10 (as shown), but this is not strictly necessary. Wire mesh 52 is stapled to the block 42 and secured to the flange 30 of the member 1 2.

Referring to Fig. 2; this shows the same lintel mounted over a window frame 44 and supporting an outer wall skin 46 and an inner wall skin 48, separated by a cavity 50. The wire mesh 52 serves to provide attachment for a layer of plaster 54. A damp course 56 is also provided in conventional manner..

Referring to Fig. 3; this shows an-alternative embodiment of lintel in which all of the angles in both members 10 and 12 are rightangles. These members are welded together along the edges 38 and 40 as in the preceding embodiment. This embodiment requires the production of only one angle, but might be less convenient in use.

Referring to Figs. 4 and 5; these show a third embodiment wherein two walls of the box section are intermittent rather than continuous. The member 1 2 has an upstanding wall 32 and downwardly inclined panel 34 along with a horizontal flange 30 (not shown). The member 10 has a horizontal flange 18 (not shown), upstanding wall 20 and upwardly inclined panel 22. The edge portion of the inclined panel 22 is provided with a series of parallel cuts by means of which alternately coplanar tongues 58 and upstanding tongues 60 are formed. The edges 62 of the coplanar tongues 58 are welded to the upright wall 32, and the edges 64 of the upstanding wall tongues 60 are welded to the edge of the downwardly inclined panel 34. This provides a box section with a significant saving in the amount of metal used.

The preceding is by no means exhaustive of the embodiments of the present invention; for instance, the walls of the downwardly-opening channel may be made to taper inwardly towards the mouth. The inclined portions 34 may be given a steeper-inclination than the inclined portion 22 so as to reduce still further the risk of damaging the damp course. It is not necessary that the two constituent members should be made of mild steel; neither is it necessary that the inclined panels 34 and 36 should be at right-angles to each other. None of the angles mentioned in the preceding description are, in fact, critical.

Claims (9)

1. A lintel comprising a downwardly-opening channel and a pair of mutually oppositely directed flanges at the lower edges of the channel for supporting respectively inner and outer skins of a cavity wall, the upper portion of the channel being formed with a longitudinally extending box section.

2. A lintel according to claim 1 wherein a wall of the box section is intermittent.

3. A lintel according to claim 1 or claim 2 formed from two sheets of steel bent to shape and welded together, each sheet providing one said flange and an upright wall of the channel, and optionally part of the box section.

4. A lintel according to claim 3 wherein one of the sheets has an upwardly sloping panel extension at the upper edge of its respective upright wall -of.the-channel, and the other sheet has a downwardly sloping panel extension at the upper edge of its respective upright wall of the channel, said panel extensions providing two walls of the box section.

5. A lintel according to claim 3 or claim 4 wherein the upright wall of one said sheet, or an extension thereof, is welded to the upright wall of said other sheet, and the upper edge portion of the upright wall of said other sheet is bent over and welded so as to form said box section.

6. A lintel according to claim.5 wherein said upper edge portion is welded to the upright wall, or an extension thereof, of said one sheet thereby forming said box section.

7. A lintel according to any one of claims 3 to 6 wherein the two pieces of sheet steel are of differing gauges according to the varying requirements for the inner and outer parts of the lintel.

8. A lintel according to any one of the preceding claims wherein a wooden block is provided held within the upright walls of the downwardly-opening channel and a layer of wire mesh attached to said wooden block and the horizontal flange supporting the inner skin.

9. A lintel according to any one of the preceding claims fabricated form black mild steel sheet welded together and subsequently galvanized.

1 0. A lintel according to claim 1 substantially as described herein with reference to the drawings.