GB2034386A

GB2034386A - Lintels

Info

Publication number: GB2034386A
Application number: GB7937071A
Authority: GB
Original assignee: British Steel Corp
Current assignee: British Steel Corp
Priority date: 1978-10-25
Filing date: 1979-10-25
Publication date: 1980-06-04
Also published as: GB2034386B

Abstract

A lintel for a cavity wall comprising a first member 1 having a web 7 for spanning the cavity and two vertically spaced and substantially horizontal arms 5, 6, located at either end of and on opposite sides of the web, a second member 2 having a substantially vertical web 13 and two vertically spaced substantially horizontal arms 11, 12, located at either end of and on the same side of the web to form a channel therewith, the webs of the members being spaced apart at least at their lower ends, the uppermost arms 5, 11, of the members adjoining each other and the lowermost arms 6, 12, being spaced apart and facing outwardly from the members in opposite directions, spacing means 3 secured between the webs of the members to maintain the lowermost arms spaced apart, stiffening means 4 secured within the channel and adapted to maintain the uppermost arm in fixed relationship relative to the web, insulating material located within the channel and extending rearwardly of the channel to a point at or near its rear edges together with keying means located adjacent the rear edges of the channel. <IMAGE>

Description

SPECIFICATION Improvements in lintels The present invention relates to lintels for spanning openings in cavity walls.

According to the present invention there is provided a lintel for a cavity wall comprising a first member having a web for spanning the cavity and two vertically spaced and substantially horizontal arms located at either end of and on opposite sides of the web, a second member having a substantially vertical web and two vertically spaced substantially horizontal arms located at either end of and on the same side of the web to form a channel therewith, the webs of the members being spaced apart at least at their lower ends, the uppermost arms of the members adjoining each other and the lowermost arms being spaced apart and facing outwardly from the members in opposite directions, spacing means secured between the webs af the members to maintain the lowermost arms spaced apart, stiffening means secured within the channel and adapted to maintain the uppermost arm in fixed relationship relative to the web, insulating material located within the channel and extending rearwardly of the channel to a point at or near its edges together with keying means located adjacent the rear edges of the channel.

Preferably the stiffening means comprises a plurality of metal plates spaced along the length of the channel. Suitably the plates are arranged transversely of, and are secured to, the arms and the web of the channel.

Conveniently the lowermost arms of the members are located in the same horizontal plane.

Preferably the spacing means lies in the same horizontal plane as the lowermost arm and conveniently comprises either a single plate extending along the lintel or a series of spaced plates extending along the lintel.

Preferably the web of the first member has a substantially vertical portion adjoining the lowermost arm, and an inclined portion adjoining the uppermost arm and the vertical portion.

An embodiment of the invention will now be particularly described with reference to the accompanying drawings in which: Figure 1 is a rear perspective view of the lintel, according to the present invention, Figure 2 is a rear elevation of the lintel shown in Fig. 1, Figure 3 is a side elevation of the lintel shown in Figs. 1 and 2 and Figure 4 is a side elevation of another embodiment of the invention.

Referring to the Figs. 1 to 3 the lintel comprises a first member 1, a second member 2, a spacer plate 3 and a pair of transverse channel stiffening plates 4.

The first member 1 is of generally Z-sectiion and has upper and lower horizontal arms or flanges 5 and 6 located at either end of and on opposite sides of a web member 7. Lower most flange 6 is adapted to be engaged with the outer skin of a cavity wall and is provided with a slightly downwardly inclined drip lip 8 whose purpose is well-known in the art. Up permost flange 5 is adapted to be engaged with the inner skin of the cavity wall. WebW member 7 is in two portions 9, 10 and in use spans the cavity of the wall and acts as a damp resistor plate. Portion 9 of web member 7 extends vertically from lowermost flange 6 and meets an inclined portion 10 which joins with the uppermost flange 5.

The second member 2 is of generally chan nel section having upper and lower horizontal arms or flanges 11, 12, for engaging with the inner skin of the wall and a vertical web member 1 3 linking the flanges 11 and 1 2.

Uppermost flange 5 of Z-member 1 overlaps a portion of uppermost flange 11 of channel member 1 and is secured thereto by welding.

The lower flanges 6 and 1 2 are spaced apart as are webs 9, 13, and this spacing is maintained by means of a spacer plate 3 which extends parallel to the longitudinal edges of the members 1 and 2. The spacer plate 3 is secured to the members 1 and 2 by welds 14 and as shown in Fig. 3 lies in the same horizontal plane as lower flanges 6 and 12. The plate 3 forms with the webs 9 and 1 3 a closed box structure imparting to the lintel considerable rigidity and resistance to flexing under load.

The channel member 2 is provided with a pair of steel plates 4 which are located transversely of the lintel and are situated close to each end of the channel member 2. The plates 4 are welded to the flanges 11, 1 2 and the web 1 3 of the channel member 2. The plates 4 impart considerably stiffness to the channel and substantially reduce or prevent the flexing of the upper flange 11 under load.

Indeed any flexing of the web 1 3 and lower flange 1 2 is also minimised.

While not shown, the base of the lintel (the lower surface of the flanges 6, 1 2 and spacer 3) can be provided with conventional means e.g. expanded metal laths, for enabling plaster or other facing material to be attached to the lintel.

Fig. 4 illustrates a lintel in which the spacing plate 3 is located at a position somewhat above the horizontal plane occupied by the flanges 6, 1 2. The other parts of the lintel are otherwise identical to those shown in Figs. 1 to 3, and it is found that the rigidity of the structure is relatively unaffected by positioning the plate 3 thus.

While not illustrated, it will be appreciated that the spacing means can comprise a series of spaced plates extending longitudinally along the lintel length.

Claims

1. A lintel for a cavity wall comprising a first member having a web for spanning the cavity and two vertically spaced and substantially horizontal arms located at either end of and on opposite sides of the web, a second member having a substantially vertical web and two vertically spaced substantially horizontal arms located at either end of and on the same side of the web to form a channel therewith, the webs of the members being spaced apart at least at their lower ends, the uppermost arms of the members adjoining each other and the lowermost arms being spaced apart and facing outwardly from the members in opposite directions, spacing means secured between the webs of the members to maintain the lowermost arms spaced apart, stiffening means secured within the channel and adapted to maintain the uppermost arm in fixed relationship relative to the web, insulating material located within the channel and extending rearwardly of the channel to a point at or near its rear edges together with keying means located adjacent the rear edges of the channel.

2. A lintel as claimed in claim 1 in which the stiffening means comprises a plurality of metal plates spaced along the length of the channel.

3. A lintel as claimed in claim 2 in which the plates are arranged transversely of, and are secured to, the uppermost arm of the first member, the T-upright and the first arm of the T cross-member.

4. A lintel as claimed in any preceding claim in which the T cross-member and the lowermost arm of the first member are- located in the same horizontal plane.

5. A lintel as claimed in any preceding claim in which the web of the first member has a substantially vertical portion adjoining the lowermost arm, and an inclined portion adjoining the uppermost arm and the vertical portion.

6. A lintel as claimed in any preceding claim in which the keying means is secured to the stiffening means.

7. A lintel as claimed in claim 6 in which the keying means comprises a board.

8. A lintel as claimed in any preceding claim in which the insulating material is in the form of blocks or slabs.

9. A lintel as claimed in any preceding claim in which the insulating material is a foamed plastics material.

10. A lintel as claimed in claim 9 in which the material is polyurethane, polystyrene, polyvinyl chloride or a phenol formaldehyde resin.

11. A lintel as claimed in claim 10 in which the insulating material is a mineral wool fibre.

1 2. A lintel substantially as hereinbefore described with reference to the accompanying drawings.