GB2301124A

GB2301124A - Lintel

Info

Publication number: GB2301124A
Application number: GB9610080A
Authority: GB
Inventors: George Rabbitts; Michael Elwine
Original assignee: Expanded Metal Co Ltd
Current assignee: Expanded Metal Co Ltd
Priority date: 1995-05-26
Filing date: 1996-05-14
Publication date: 1996-11-27
Anticipated expiration: 2016-05-14
Also published as: GB9610080D0; GB9510691D0; GB2301124B

Abstract

A lintel having a body which is rolled or formed by press braking a single sheet of material. The lintel comprises inner 1 and outer 2 substantially co-planar flanges which are connected by a symmetrical inverted U-shape channel portion 3. The channel portion comprises a pair of substantially parallel side walls 4, 5 which extend from respective flange portions into respective upwardly and inwardly extending inclines 6, 7 which are joined by a flat 8.

Description

STRUCTURAL ELEMENT The present invention relates to a structural element such as a lintel. Lintels are known having a wide variety of profiles.

According to the present invention a lintel has a body which is rolled or formed by press breaking from a single sheet of material and comprises inner and outer substantially co-planar substantially horizontal flange portions which are connected by a symmetrical inverted Ushape channel portion comprising a pair of substantially parallel upstanding side walls which, at one end, extend from the respective flange portions, and at the other end extend into respective upwardly and inwardly extending inclines, the inclines being joined to one another by a substantially horizontal flat.

Such a profile offers the high strength and stiffness required of a lintel, and the combination of the symmetrical portion and substantially parallel walls together with the flat allows the lintel to be simply manufactured by a series of rolling or pressing operations so that it is cheap and easy to produce variations to suit different masonary constructions.

Preferably, an array of apertures is provided on at least one of the flanges to provide a plaster key. The apertures can be through holes, but are more preferably tabs formed by cutting an array of pairs of slits in the flange and locally deforming the material between each respective pair of slits out of the plane of the flange.

Preferably, each side wall is provided with an inwardly facing rib so that a block formed with complementary grooves can be retained between the two side walls to increase the rigidity of the lintel. In this case, it is also possible to attach a mesh to the block, for example using a staple, to provide an additional plaster key across the cavity area allowing flexibility of positioning of windows and doors across masonary walls.

The mesh will generally be metal or plastic.

In order to insert the block into the lintel, a tool is preferably provided for use with the lintel. The tool has a camming head which across one dimension is less than the spacing between the side walls of the lintel to allow its insertion between the side walls, and across another dimension is larger than the spacing between the side walls of the lintel so that when the tool head is rotated from its inserted position, the side walls are resiliently spread to allow the insertion of the block into the mouth of the channel portion.

Alternatively, a plate can be provided across the mouth of the channel portion, and fixed at each end to a respective flange portion at a position adjacent to the respective side walls. The plate substantially increases torsional resistance of the lintel in asymmetric loads.

The plate may be provided with apertures to provide an additional plaster key.

Two examples of lintels constructed in accordance with the present invention will now be described with reference to the accompanying drawings in which: Fig. 1 shows the profile of a first example; and Fig. 2 shows the profile of a second example.

The bodies of the lintels shown in figures 1 and 2 are made of steel, which is preferably galvanised, and have a generally similar profile. The profile comprises inner 1 and outer 2 flanges. The two flanges are connected by a Ushape channel portion 3 which is symmetrical about vertical axis in figures 1 and 2. The channel portion 3 has side walls 4, 5 each of which extends from a respective flange 1, 2 into a respective incline 6, 7. The inclines are at an angle of 250 to the horizontal as shown in figures 1 and 2, to enhance the structural stiffness of the lintel. The inclines 6, 7 are joined by a flat 8 which, in use, will be substantially horizontal. The inner flange 1 is shown with a plurality of apertures 9 which are formed in an array.

The apertures are formed by cutting an array of pairs of parallel slots into the flange 1, and deforming the material between each pair of slots out of the plane of the flange generally in an arch shape.

In the example shown in figure 1, each side wall 4, 5 is provided with an inwardly facing rib 10. A timber or plastic block 11 is provided with complementary grooves 12, and is positioned between the side walls 4, 5. To insert the block, a tool head is inserted into the lintel from one end at a location above the position to be occupied by the block. The tool head has a camming surface, so that rotation of the tool head in the lintel body spreads the side walls 4, 5 to a sufficient extent to allow the block to be inserted through the mouth of the channel portion and between the ribs 10. Further rotation of the tool head allows the side walls 4, 5 to return resiliently to their original position whereupon the ribs 10 mate with the grooves 12 in the block 11, so that the block is a sliding fit in the lintel body, and the tool can be removed. In practice a row of spaced blocks will be inserted in the manner described. The space between the blocks is filled with polystyrene blocks 13. A mesh 14 which provides a plaster key is stapled to block 11 by a staple 15.

In figure 2 a plate 16 is provided across the mouth of the channel portion 3 and is fixed at each end to a respective flange by clinching, riveting or welding. The plate 16 is provided with apertures 17 similar to those on the flange 1, and the space above the plate is filled with a polystyrene block 18.

Claims

1. A lintel comprising a body which is rolled or formed by press breaking from a single sheet of material and comprises inner and outer substantially co-planar substantially horizontal flange portions which are connected by a symmetrical inverted U-shape channel portion comprising a pair of substantially parallel upstanding side walls which, at one end, extend fromthe respective flange portions, and at the other end extend into respective upwardly and inwardly extending inclines, the inclines being joined to one another by a substantially horizontal flat.

2. A lintel according to claim 1, wherein an array of apertures is provided on at least one of the flanges to provide a plaster key.

3. A lintel according to claim 2, wherein the apertures are tabs formed by cutting an array of pairs of slits in the flange and locally deforming the material between each respective pair of slits out of the plane of the flange.

4. A lintel according to any one of the preceding claims, wherein each side wall is provided with an inwardly facing rib so that a block formed with complementary grooves can be retained between the two side walls to increase the rigidity of the lintel.

5. A lintel according to claim 4, wherein a mesh is attached to the block.

6. A lintel according to any one of the preceding claims, wherein a plate is provided across the mouth of the channel portion, and fixed at each end to a respective flange portion at a position adjacent to the respective side walls.

7. A lintel according to claim 6, wherein the plate is provided with apertures to provide an additional plaster key.

8. A lintel substantially as described with reference to the accompanying drawings.