GB2325258A

GB2325258A - Lintel with bracing member

Info

Publication number: GB2325258A
Application number: GB9810438A
Authority: GB
Inventors: Sean Coyle
Original assignee: Keystone Lintels Ltd
Current assignee: Keystone Lintels Ltd
Priority date: 1997-05-15
Filing date: 1998-05-15
Publication date: 1998-11-18
Anticipated expiration: 2018-05-15
Also published as: GB9810438D0; IE980370A1; GB2325258B

Abstract

A lintel is formed from one metal sheet into a substantially top-hat cross - section having two planar portions 10,12 separated by an inverted channel portion 14, whose open end is tied by bracing means to impart strength to the lintel. The bracing means includes one or more tie members extending across the open side, the tying means at the outer planar portion 10 or channel limb 18 adjacent thereto being insulated at intervals along the length of the lintel to leave a series of uninsulated contact points 20 at which the outer side of the tying means is to be secured. The tie member may be an elongate plate 16 of dimensions to fit or fit over the open side of channel portion 14. The side of the plate 16 to be secured at least at the outer planar portion 10 or channel limb 18 adjacent thereto is insulated at intervals along its length to leave a series of uninsulated contact points 20 at which the outer side of the plate 16 is secured. The insulation may be simply an air gap at portions 22, or an insulating strip. In another embodiment (Fig 5, not shown) individual bracing strips 40 are used instead of plate 16.

Description

LI NTELS This invention relates to an improved lintel of the type formed from at least one metal sheet into a substantially top hat vertical cross-sectional profile having two planar portions separated by an inverted channel portion, the web of which may, for example, be sloped, the channel portion being filed with an insulation material whose function is to prevent cold bridging between outer and inner portions.

The planar portions are to support inner and outer skins of a doubie skinned wall with the channel portion positioned in a cavity between said two skins. The inner planar portion to be located to support an inner skin of the wall is interfered with or adapted to provide a plaster key on at least its underside. A plate member of metal has sometimes been used to close off the channel and to maintain the distance between the limbs of the channel portion at its open side to add rigidity and load-bearing capacity to the lintel. Such plate member extends to overlap the outer and inner planar portions and is welded or riveted to both at its outer and inner edges. This not only causes cold bridging with the outer planar portion generally being colder than the inner planar portion but also can allow ingress of water to cause dampness on plaster secured to the inner planar portion. This is a problem which the present invention seeks to obviate or mitigate.

Accordingly, the present invention is a lintel of the type stated in which the open end of the channel portion is tied by means to import strength to the lintel, the tying means including one or more tie members extending across the open side, the tying means at the outer planar portion or channel limb adjacent thereto being insulated at intervals along the length of the lintel to leave a series of uninsulated contact points at which the outer side of the tying means is to be secured.

Preferably, the tie member is an elongate plate of dimensions to fit or fit over the open side of the channel portion, the side of the plate to be secured at least at the outer planar portion, or channel limb adjacent thereto being insulated at intervals along its length to leave a series of uninsulated contact points at which the outerside of the plate is secured.

Preferably also, the insulated lengths of the outer side of the plate are each a rebated portion, the insulation being the air gap between the rebated lengths of the outer side and the lintel.

Alternatively, the insulated lengths of the outer side of the plate each having a correspondingly length of strip insulation material to be positioned between the plate and the planar portion or channel limb..

Preferably further, the plate is recessed into the open side of the channel portion. The plate desirably has downwardly-extending flanges along each longitudinal side. The plate is beneficially secured to the lintel by spot welding the flanges to the limbs of the channel portion.

In an alternative embodiment, the tie member is a strap of dimensions to fit or fit over the width of the open side of the channel portion, and a series of straps are spaced apart along the length of the channel portion with one of the series being positioned at or near to each end of the open side of the channel portion.

The straps may be separate from and secured to the lintel by spot welding.

Alternatively, the straps may be punched out of the limb of the channel portion adjacent to the rear planar portion, folded co-planar with the planar portions and spot-welded to the outer planar portion or channel limb adjacent thereto.

The two opposite end walls of the channel portion are preferably also closed off by respective end plates.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying schematic drawings in which: Fig. 1 is a cross-sectional view of a lintel according to a first embodiment of the present invention; Fig. 2 is a plan view of a tie member shown in Fig. 1; Fig. 3 is a cross-sectional view of a lintel according to a second embodiment; Fig. 4 is an undemeath plan view of a portion of the lintel shown in Fig. 3; and Fig. 5 is an underneath plan view of a portion of a lintel according to a third embodiment.

Referring to the drawings of both the first and second embodiments, a lintel of the type stated has the open end of the channel portion tied by means to import strength to the lintel. The tying means is a tie member in the form of a plate 16 to close off the open side of a channel portion 14. The plate 16 is elongate and of dimensions to fit the open side of the channel portion 14. The side 24 of the plate 16 which is to be secured at the outer planar portion 10, or channel limb 18 adjacent thereto, is insulated at intervals along its length to leave a series of uninsulated contact points 20 at which the outer side 24 of the plate 16 is to be secured.

The insulated lengths 22 of the outer side 24 of the plate 16 are each a rebated portion as shown in Fig. 2 or 4, the insulation being the air gap between the rebated lengths 22 of the outer side 24 and the lintel. Insulated lengths 22 may also be provided along the inner side 25.

The undersurface of the plate 16 is interfered with to provide a plaster key.

This interference is achieved by providing a series of indentations 30 (not shown in Fig. 4) which may involve the material being cut on opposite sides of each indentation.

The two opposite end walls (not shown) of the channel portion 14 are also closed off by, respective end plates (not shown).

The end walls of the channel portion are spot welded to the limbs and can either be spot welded to the plate 16 or there can be an interconnection between the end walls and the plate 16. Also, the end walls may be fitted to the limbs of the channel portion by interconnecting protuberances and corresponding recesses.

In an alternative (not shown) to either of the embodiments, the insulated lengths 22 of the outer side 24 of the plate 16 each has a correspondingly length of strip insulation material.

In the first embodiment, the plate 16 is recessed as shown particularly in Fig.

2 into the open side of the channel portion 14 with downwardly-extending flanges 26 provided along each of its two longitudinal sides. The plate 16 is secured to the lintel by spot welding the flanges 26 to the respective limbs 18 of the channel portion 14, the plate 16 being spaced from the bottom of the limbs 18 by the depth of the flanges 26 as shown in Fig. 1. The plate 16 has a groove 28 running lengthwise and mid-way of its width, the groove being of a depth equal to the depth of the flanges 26 and imparting additional rigidity to the plate. Alternatively, the plate 16 is flat.

In the second embodiment in which like parts are denoted by like numerals and shown in Figs. 3 and 4, the plate 16 is flat and of width greater than the width of the open side of the channel portion. The insulated lengths 22 of the outer side 24 are each a rebated portion as shown in Fig. 4 with the insulation being the air gap between the rebated lengths 22 of the outer side 24 and the lintel. The uninsulated contact points 20 are lugs to be spot welded to the outer planar portion. Fig. 4 also shows a similar arrangement at the inner side 25 with rebated insulated lengths 22 and uninsulated tabs. The lungs at the outer side 24 and the inner side 25 are not aligned as shown in Fig. 4.

In a third embodiment as shown in Fig. 5 and in which like parts are denoted by like numerals, the tie member is a strap 40 of dimensions to fit or fit over the width of the open side of the channel portion 14. A series of straps 40 are spaced apart along the length of the channel portion 14 with one of the series being positioned at or near to each end of the open side of the channel portion 14. The two straps 40 are at or near to each end of the channel portion 14 may be of the same dimensions, however the intermediate strap(s) 40 may be of the same or broader dimensions.

The straps 40 are separate from and secured to the lintel by spot welding.

Alternatively, the straps 40 may be formed of tongues punched out of the limb 18 of the channel portion adjacent to the rear planar portion 12, the tongues being folded co-planar with the planar portions 10,12 and spot welded to the outer planar portinn 10 or channel limb 18 adjacent thereto. The spaces between the straps 40 secured to the outer planar portion 10 serving as the insulated intervals.

A lintel as described above in each of the embodiments can be made of lighter gauge material than heretofore and still retain rigidity and load-bearing capacity. For example, a four foot (1200 mm) length lintel using a block of insulation material and formed from a metal sheet of 1.6 mm thickness weights around 6 kilograms as compared to a present lintel of the type stated which is made out of sheet 2.6 mm thickness and weighs around 9 kilograms. The lintel according to this example, or equivalent different lengths of lintel, are advantageous over existing lintels since they are cheaper to manufacture, and more lintels can be accommodated on a pallet for storing and transporting resulting in cheaper transport costs and yet the lintels have the same or comparable or improved amount of rigidity and load-bearing capacity as heretofore with existing lintels. The lintels also have the same or comparable low thermal conductivity between outer and inner planar portions compared with existing lintels not having plate members.

It is also possible to use with the invention any type of insulation material in the channel portion, for example a block of expanded polystyrene beads in any one of the embodiments of the invention or, in-situ expanded foamed material, adhered discrete filler such as sticky-coated expanded polystyrene beads, or thermoplastic or hollow glass microspheres; or loose fill material such as discrete fillers, or mineral or fibre wool in either of the first or second embodiments wherein the channel portion has end plates.

To secure a block of expanded polystyrene beads in a channel portion, one or more holes are provided in the outer or inner limb 18 of the channel portion and a plastic plug 42 is pushed through the or each hole into the block. The plugs 42 may be a tight friction fit in the holes.

Variations and modifications can be made without departing from the scope of the invention described above and as claimed hereinafter.

Claims

1. A lintel of the type stated in which the open side of the channel portion is tied by means to import strength to the lintel, the tying means including one or more tie members extending across the open side, the tying means at the outer planar portion or channel limb adjacent thereto being insulated at intervals along the length of the lintel to leave a series of uninsulated contact points at which the outer side of the tying means is to be secured.

2. A lintel as claimed in Claim 1, wherein the tie member is an elongate plate of dimensions to fit or fit over the open side of the channel portion, the side of the plate to be secured at least at the outer planar portion, or channel limb adjacent thereto being insulated at intervals along its length to leave a series of uninsulated contact points at which the outerside of the plate is secured.

3. A lintel as claimed in Claim 2, wherein the insulated lengths of the outer side of the plate are each a rebated portion, the insulation being the air gap between the rebated lengths of the outer side and the lintel.

4. A lintel as claimed in Claim 2, wherein the insulated lengths of the outer side of the plate each having a correspondingly length of strip insulation material to be positioned between the plate and the planar portion or channel limb adjacent thereto.

5. A lintel as claimed in Claim 2, 3 or 4 wherein the plate is recessed into the open side of the channel portion.

6. A lintel as claimed in Claim 5, wherein the plate has downwardly-extending flanges along both longitudinal sides.

7. A lintel as claimed in Claim 6, wherein the plate is secured to the lintel by spot welding the flanges to the limbs of the channel portion.

8. A lintel as claimed in Claim 1, wherein the tie member is a strap of dimensions to fit or fit over the width of the open side of the channel portion, and a series of straps are spaced apart along the length of the channel portion with one of the series being positioned at or near to each end of the open side of the channel portion.

9. A lintel as claimed in Claim 8, wherein the straps are separate from and secured to the lintel by spot welding.

10. A lintel as claimed in Claim 8, wherein the straps are punched out of the limb of the channel portion adjacent to the rear planar portion, folded co-planar with the planar portions and spot-welded to the outer planar portion or channel limb adjacent thereto.

11. A lintel as claimed in any one of the preceding Claims, wherein the two opposite end walls of the channel portion are also closed off by respective end plates

12 A lintel as claimed in any one of the preceding Claims, wherein with the insulation in the channel portion being a block of expanded polystyrene, one or more holes are provided in the inner limb of the channel portion and a plug is inserted therethrough into the block to retain the block within the channel portion.

13. A lintel substantially as hereinbefore described with reference to Figs. 1 and 2 of the accompanying drawings.

14. A lintel substantially as hereinbefore described with reference to Figs. 3 and 4 of the accompanying drawings.

15. A lintel substantially as hereinbefore described with reference to Fig. 5 of the accompanying drawings.