GB2435057A

GB2435057A - Lintel of glass reinforced plastics

Info

Publication number: GB2435057A
Application number: GB0701156A
Authority: GB
Inventors: John Plunkett Coyle
Original assignee: Keystone Lintels Ltd
Current assignee: Keystone Lintels Ltd
Priority date: 2006-02-13
Filing date: 2007-01-22
Publication date: 2007-08-15
Also published as: GB0701156D0; GB0602825D0

Abstract

A lintel is integrally formed by pultrusion from glass reinforced plastics. The formed lintel has a hollow upright elongate central portion 10 and two flat portions 12, 14, one extending outwardly from, at or near to the bottom of each side of the central portion 10. The central portion 10 may be of inverted U-shape. Means, such as webs 20, 22, 24 are provided to tie limbs 16 of the central portion 10 together. The webs 20, 22, 24 may all be parallel to a top web 26 of the central portion. A sub-base may be provided adhered to the undersides of the two flat portions 12, 14, the sub-base may provide a web member. Keying means such as dovetail channels 28, or texturing may be provided on the underside of one of the flat portions 12.

Description

LI NTELS.

This invention relates to a hntel intended for use in bridging voids in walls of a building and supporting any further sections of wall thereabove, such voids being generally for fitment of window or door frames. Lintels heretofore have been of concrete, or fabricated from metal sheet to have a box shape or a top hat shape in cross-section. The top hat shaped lintel is formed having a central inverted U-portion with two limbs connected by a web and has two fiat to portions, one extending outwardly at substantially right angles from the bottom of each limb of two limbs of the U-portion, one fiat portion being for positioning internally of the wall and the other fiat portion being for positioning on the outside of the wall. The undersurface of the internal flat portion being interfered with to provide a keying surface, and on the undersurface of the outside flat portion adjacent to the outer edge, a drip channel is provided. One of the problems in metal lintels is cold bridging ie. the conduction of cold temperature outside a wall through the metal lintel to inside a wall bounding a region having a higher temperature and thereby causing dampness on the inside wall through condensation of hot air. This invention is particularly concerned with top hat shaped lintels.

Accordingly, the present invention is a lintel integrally formed by pultrusion from glass reinforced plastics, the formed lintel having a hollow upright elongate central portion and two flat portions, one extending outwardly from, at or near to the bottom of each side of the central portion. The central portion is preferably of inverted U-shape. Means are beneficially provided to tie the limbs of the central portion together.

Preferably, a base plate is provided from substantially mid-way of which the central zs portion upstands, the part of the base plate on each side of the central portion forming the flat portions and a part therebetween forming a first web member. C Alternatively, a base plate is provided from substantially mid-way of which the central portion upstands. the part of the base plate on each side of the central portion forming upper parts of the flat portions and a sub-base plate is provided forming lower parts of the flat portions with a central part therebetween forming a first web member. The sub-base plate is preferably adhered to the undersurface of the upper parts of the fiat portions.

Preferably also, a second web member is spaced from and substantially parallel to the first web member.

Preferably further, above the second web member, one limb of the central portion slopes inwardly and at its inward end a third web member is provided substantially parallel to the first and second web members. The first, second and third web members desirably comprise the tying means. The web at the top of the central portion is desirably also substantially parallel to the first, second and third web members.

The undersurface of the inward fiat member beneficially has a series of parallel dovetail channels to provide a keying surface. Alternatively, the undersurface may simply be textured or roughened.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing which shows a perspective view of a lintel according to U the present invention.

Referring to the drawings, a lintel is integrally formed by put trusion from glass reinforced plastics. The formed lintel has a hollow upright elongate central portion 10 and two fiat portions 12, 14, one extending outwardly from the bottom of each side of the central portion 10. The central portion 10 has two lateral substantially parallel limbs 16 connected at their top edge by a web. The central portion 10 is of inverted U shape. Means are provided to tie the limbs 16 of the central portion 10 together.

A base plate 18 is provided from substantially mid-way of which the central portion 10 upstands, the part of the base plate 18 on each side of the central portion 10 forming the fiat portions 12, 14 and the part therebetweefl forming a first web member 20.

A second web member 22 is spaced from and substantially parallel to the first web member 20.

Above the second web member 22, one limb 16 of the central portion 10 is cranked inwardly and at the inward end of the sloped portion 25 a third web member 24 is provided substantially parallel to the first and second web members 20, 22. The first, second and third web members 20, 22, 24 comprise the tying means. The web 26 at the top of the central portion 10 is also substantially parallel to the first. second and third web members 20. 22, 24.

The undersurface of the inward flat portion 12 has a series of parallel dovetail channels 28 to provide a keying surface. A drip channel 30 is provided adjacent to the outer edge of the undersurface of the flat portion 14.

Pultrusion is a continuous process in which reinforcing fibres are impregnated with a duroplastic resin, fed to a heated tool (according to a shape of a required profile) wherein the profile is cured and then pulled out and cut to required lengths. The fibres are normally glass io reinforced plastics (GRP). The profile normally has unidirectional glass fibre roving in the centre of the profile to carry the longitudinal forces. The profile is cross-reinforced with mats of glass fibre. A surface veil can be used to improve protection against UV radiation and wear-out.

Standard isophtalic polyester resins are used for the matrix. The particular resin may be a vinylester resin to resist corrosion.

is In use, a lintel above described is used in a conventional manner.

In a first modification, the base plate 18 is provided from substantially mid-way of which the central portion 10 upstands. the part of the base plate 18 on each side of the central portion forming upper parts of the flat portion 12. 14 and a sub-base plate (not shown) is provided forming lower parts of the flat portions 12, 14 with a central part therebetweefl forming the first zo web member 20. The sub-base plate is adhered to the undersurface of the upper parts of the flat portions 12, 14.

In a second modification, the undersurface of the inward flat portion 12 may simply be textured or roughened instead of having channels provided.

In a third modification one or more of the three voids created between the limbs 16, web 26 and web members 20, 22 and 24 may be filled with insulation material.

A beneficial feature of this invention is that the elongate central portion and the web members are of a cross-section suitable to provide the I' value necessary to make the lintel structurally strong enough for the load anticipated to be exerted thereupon.

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

Claims

CLAIMS

1. A lintel integrally formed by pultrusion from glass reinforced plastics. the formed lintel having a hollow upright elongate central portion and two flat portions one extending outwardly from, at or near to the bottom of each side of the central portion.

2. A lintel as claimed in Claim 1 wherein the central portion is of inverted U-shape.

3. A lintel as claimed in Claim 1 or 2, wherein means are provided to tie the limbs of the central portion together.

4. A lintel as claimed in Claim 1, 2 or 3, wherein a base plate is provided from substantial1'! mid-way of which the central portion upstands. the part of the base plate on each side of the central portion forming the flat portions and a part therebetWeen forming a first web IS member.

5, A lintel as claimed in Claim 1. 2 or 3, wherein a base plate is provided from substantially mid-way of which the central portion upstnds. the part of the base plate on each side of the central portion forming upper parts of the flat portions and a sub-base plate is provided forming lower parts of the flat portions with a central part therebetWeen forming a first web member.

6. A lintel as claimed in Claim 5. wherein the sub-base plate is adhered to the undersurface of the upper parts of the flat portions.

7 A lintel as claimed in Claim 4, 5 or 6, wherein a second web member is spaced from and substantially parallel to the first web member.

8. A lintel as claimed in Claim 7, wherein above the second web member one limb of the central portion slopes inwardly and at its inward end a third web member is provided S substantially parallel to the first and second web members.

9 A lintel as claimed in Claim 8, wherein the first, second and third web members comprise the tying means.

io 10. A lintel as claimed in Claim 8 or9, wherein the web at the top of the central portion is also substantially parallel to the first, second and third web members.

ii. A lintel as claimed in any one of the preceding Claims, wherein the undersurface of the inward flat portion has a series of parallel dovetail channels to provide a keying surface.

U

12. A lintel as claimed in any one of Claims ito 10. wherein the undersurface of the inward flat portion is textured or roughened.

13. A lintel as substantially as hereinbe fore described with reference to and as shown in the accompanying drawing.