GB2539118A

GB2539118A - A hybrid support structure

Info

Publication number: GB2539118A
Application number: GB1612805.0A
Authority: GB
Inventors: Coyle Sean
Original assignee: Keystone Lintels Ltd
Current assignee: Keystone Lintels Ltd
Priority date: 2010-04-16
Filing date: 2011-04-20
Publication date: 2016-12-07
Anticipated expiration: 2031-04-20
Also published as: GB2479656A; GB201006408D0; GB201612805D0; IE20170125A1; IE86895B1; GB201106698D0; GB2479656B; IE20110200A1; IE86820B1; GB2539118B

Abstract

The lintel 1 comprises a first outer elongate member 2, which is made from a composite with a fibre reinforced polymeric matrix material, is mechanically coupled to a second inner elongate member 3 made of metal or metal alloy. In use the elongate members are arranged such that only the outer member is exposed to the atmosphere, and the second member is protected from the atmosphere. The inner member may have an L shaped cross section arranged so that it is mechanically coupled in a back to back manner with the outer member.

Description

A HYBRID SUPPORT STRUCTURE

The present invention relates to a hybrid support structure and in particular to a hybrid lintel.

Support structures are used in all forms of constructions from buildings to vehicles such as ships and airplanes. A common form of support structure used above a door or window opening in a wall is a lintel. The support structure is required to take the weight of the material above the aperture to provide structural support to the wall to avoid this material collapsing into the aperture. Traditionally, lintels have been manufactured from the likes of reinforced concrete and steel. Lintels have been provided in a multitude of configurations from traditional unitary components to multiple components coupled together with insulation there between. Additionally, where at least a portion of the lintel is exposed to the elements steel lintels are galvanized to avoid rusting of the exposed portion of the lintel maintaining the structural integrity of the lintel.

Unitary reinforced concrete lintels are heavy often requiring specialist lifting equipment on site when they exceed a certain weight. Steel lintels are becoming increasingly expensive because of the recent industrial revolutions in rapidly developing regions such as China, Brazil and India. Furthermore, the requirement to galvanize steel to prevent corrosion by inclement weather conditions adds significantly to the manufacturing complexity and overall production cost.

It is an object of the present invention to obviate or mitigate the problems associated with prior art support structures such as lintels outlined above.

Accordingly, the present invention provides an elongate hybrid lintel comprising a first outer elongate member mountable on the outer leaf of a cavity wall so that at least a portion of the elongate outer member is in contact with the atmosphere and a second inner elongate member mountable on the inner leaf of the cavity wall and being mechanically coupled to the first outer elongate member so that the second inner elongate member is protectable from the atmosphere in use, the outer elongate member is a composite member having a polymeric matrix reinforced with fibres and the inner elongate member is a metal or metal alloy reinforcing member attached thereto, the reinforcing member is mechanically coupled to an external portion of the elongate composite member, this coupling reducing the web buckling effect of both members, the first outer elongate member having a low thermal conductivity value compared to the thermal conductivity value of the inner elongate member to act as a thermal barrier to the ingress of cold, the elongate hybrid lintel acts as a barrier to a major pathway for thermal conductivity between the outside atmosphere and the inside of the cavity wall incorporating the elongate hybrid lintel and the inner elongate reinforcing member provides additional structural support to the elongate composite member and provides the hybrid lintel with the required resistance to web buckling.

Advantageously, the elongate hybrid support structure acts as a barrier to a major pathway for thermal conductivity between the outside atmosphere and the inside of a structure incorporating the elongate hybrid support structure.

Ideally, the second inner elongate member is mechanically coupled to the first outer elongate member in a back to back configuration.

Preferably, the elongate outer member has an open profile cross section.

Ideally, the elongate outer member comprises a plurality of integral planar elements. Preferably, the elongate outer member is extruded, pultruded, moulded or folded. Preferably, the elongate inner member comprises an open profile cross section.

Preferably, the elongate inner member comprises a plurality of integral planar elements.

Ideally, the thermal conductivity of the outer elongate member is less than 1 W/mK. Preferably, the thermal conductivity of the outer elongate member is less than 0.5 W/mK.

Ideally, the inner elongate member is produced from steel. Advantageously, steel provides additional structural support to the elongate outer member.

Ideally, the inner elongate member is provided by an elongate L-shaped plate mechanically coupled to an external portion of the elongate outer member. Advantageously, this coupling reduces web buckling effect of both members.

Ideally, the elongate inner steel member and the outer composite elongate member are mechanically coupled together in a back to back arrangement. Advantageously, the elongate composite outer member is exposable to the elements in use whereas the elongate inner steel member is protected from the elements. In this configuration, it is not necessary to galvanise an elongate member manufactured from steel reducing the overall manufacturing complexity and cost.

It is known in the prior art to use steel lintels separately and their major technical drawbacks are well documented namely corrosion and cold bridging as steel has a high thermal conductivity value. The major technical advantages of steel lintels is their strength under loading and their resistance to web bucking in elongate support structures. GRP lintels are also known in the prior art and the disadvantages associated with GRP lintels are the associated costs of manufacture and their perceived lack of strength under loading and non resistance to web buckling. The present hybrid lintel comprises an inner leaf of steel being mechanically coupled to an outer composite elongate member such as reinforced plastic. The inner leaf of steel is protected from the environment in use to avoid the step of galvanizing the lintel reducing the cost of the manufacturing process whilst providing the hybrid lintel with good loading strength and the required resistance to web buckling. The outer composite elongate member provides the resistance to corrosion and also provides a thermal barrier to the ingress of cold. In this way, the hybrid lintel takes the advantages of both types of material and removes their weakest features by the configuration of the two elongate members in a back to back arrangement.

Ideally, the elongate composite member is provided by fiber-reinforced polymers, FRPs, carbon-fiber reinforced plastic CFRP or glass-reinforced plastic GRP. Preferably, the matrix is provided by a thermoplastic composite.

Ideally, the thermoplastic composite is a short fiber thermoplastics, a long fiber thermoplastics or a long fiber-reinforced thermoplastics.

Alternatively, the matrix is provided by a thermoset composite.

Ideally, the elongate composite member is provided by aramid fibre and carbon fibre in an epoxy resin matrix.

Preferably, the FRPs include wood comprising cellulose fibers in a lignin and hemicellulose matrix.

The inner elongate member is mountable on the inner leaf of a cavity wall.

Advantageously, this arrangement shelters the inner elongate member from inclement weather conditions so that no galvanizing is required where steel is used.

The outer elongate member is mountable on the outer leaf of the cavity wall. Advantageously, the weather proof exterior of the elongate composite member is suitable for exposure to any weather conditions and acts as a thermal barrier.

Ideally, the elongate inner member has a generally L-shaped profile.

Preferably, the elongate inner member is formed by rolling or folding a sheet of metal or metal alloy into the desired profile.

Preferably, the elongate inner member has a generally h-shaped profile.

Ideally, the two opposing free ends of the legs of the h-shaped profile engage the upstanding web of the L-shaped profile.

Means are provided for mechanically coupling the elongate outer member and the elongate inner member together.

Preferably, the mechanical coupling means apply a compressive force to an interface between the elongate outer member and the elongate inner member.

Preferably, at least a portion of the free edge of the upstanding web of the L-shaped profile has a coupling bend section.

Ideally, the elongate outer member has a correspondingly located coupled bend section extending from an end of one of the leg portions of the h-shaped profile.

Preferably, the coupling bend section of the elongate inner member is formed for receiving the coupled bend section of the elongate composite member.

Ideally, the dimensions of the coupling bend section and the coupled bend section are predetermined so that the coupling bend section applies a compressive force onto the coupled bend section. Advantageously, this arrangement ensures that the elongate outer member and the elongate inner member remain firmly secured together in use.

Preferably, additional mechanical fixing members are also provided at the interface between the elongate outer member and the elongate inner member.

Ideally, the additional mechanical fixing members are provided by rivets, studs or intermittent tongue and slot arrangements or any similar mechanical fixing arrangements.

Preferably, a second embodiment of mechanical fixing arrangement is provided between the outer elongate member and the inner elongate member.

Ideally, a plurality of spaced apart male or female connecting members protrude from the rearward facing surface of the inner elongate member.

Preferably, these spaced apart male or female connecting members are formed for mechanically coupling with correspondingly located female or male members respectively on the outer elongate member.

Ideally, the free end of the upstanding web of the L-shaped profile has a bulb, flange or excess of material to stiffen the L-shaped profile thereby improving the structural performance of the lintel.

Ideally, the elongate inner member is manufactured from steel or aluminium. Alternatively, the inner elongate member is manufactured from wood.

Accordingly, the present invention also provides an elongate metal or metal alloy inner member having means for mechanically coupling the elongate metal or metal alloy inner member to a second elongate outer member.

Ideally, the second elongate outer member has a low thermal conductivity value and is mechanically coupled in a back to back arrangement with the inner elongate member so as to form a hybrid support structure.

Preferably, the mechanical coupling means comprise ribs or slots extending along at least a portion of the elongate metal or metal alloy inner member.

Accordingly, the present invention also provides an elongate outer member with a low thermal conductivity value having means for mechanically coupling the elongate outer member to a second elongate inner member in a back to back arrangement so as to form a hybrid support structure.

Preferably, the mechanical coupling means comprise ribs or slots extending along at least a portion of the elongate outer member.

The invention will now be described with reference to the accompanying drawings which show by way of example only three embodiments of elongate hybrid support structure in accordance with the invention. In the drawings: Figure 1 is a sectional view of the elongate hybrid support structure; Figure 2 is a detail view of the coupling arrangement; Figure 3 is a detail view of the interface between the elongate composite member and the elongate reinforcing member; Figure 4 is a sectional view of a second embodiment of elongate hybrid support structure; and Figure 5 is a sectional view of a third embodiment of elongate hybrid support structure.

In the drawings, there is shown an elongate hybrid support structure indicated generally by the reference numeral 1 having a first outer elongate member 2 mountable so that at least a portion of the elongate outer member 2 is in contact with the atmosphere and a second inner elongate member 3 mechanically coupled to the first outer elongate member 2 in a back to back configuration so that the second inner elongate member 3 is protected from the atmosphere in use. The first outer elongate member 2 has a low thermal conductivity value to act as a thermal barrier to the ingress of cold. Advantageously, the elongate hybrid support structure 1 acts as a barrier to a major pathway for thermal conductivity between the outside atmosphere and the inside of a structure incorporating the hybrid support structure 1.

The elongate outer member 2 has an open profile cross section and comprises of integral planar elements 8. The elongate outer member 2 is extruded, pultruded, moulded or folded. The elongate inner member 3 also has an open profile cross section and has a plurality of integral planar elements 9, 25.

The outer elongate member 2 is a composite member 2 having a polymeric matrix reinforced with fibres and the inner elongate member 3 is a metal or metal alloy reinforcing member 3 attached thereto. In the embodiment shown in Figures 1 to 3 of the drawings, the reinforcing member 3 is mechanically coupled to an external portion of the elongate composite member 2.

Advantageously, the reinforcing member 3 provides additional structural support to the elongate composite member 2. The elongate composite member 2 and the reinforcing member 3 are mechanically coupled together in a back to back arrangement. Advantageously, the elongate composite member 2 is exposed to the elements in use whereas the reinforcing member 3 is protected from the elements in use being located on the inner leaf of a cavity wall. In this configuration, it is not necessary to galvanise the reinforcing member 3 when it is manufactured from steel. Advantageously, this reduces the overall manufacturing complexity and cost.

The elongate composite member 2 is provided by fiber-reinforced polymers, FRPs, carbon-fiber reinforced plastic CFRP or glass-reinforced plastic GRP with the most preferable material being glass fibre reinforced plastic. Preferably, the matrix is provided by a thermoplastic composite such as short fiber thermoplastics, a long fiber thermoplastics or a long fiber-reinforced thermoplastics.

In an alternative arrangement, the matrix is provided by a thermoset composite or a further arrangement is provided by aramid fibre and carbon fibre in an epoxy resin matrix.

The FRPs include wood comprising cellulose fibers in a lignin and hemicellulose matrix.

The reinforcing member 3 comprises an inner elongate component of the elongate hybrid support structure 1 and the reinforcing member 3 is mounted on the inner leaf of a cavity wall in use. Advantageously, this arrangement shelters the reinforcing member 3 from inclement weather conditions so that no galvanizing is necessary where steel is used for manufacturing the reinforcing member 3. The elongate outer member 2 is mounted on the outer leaf of the cavity wall in use. Advantageously, the weather proof exterior of the elongate outer member 2 is suitable for exposure to any weather conditions.

The elongate inner member 3 has a generally L-shaped profile and is formed by rolling or folding a sheet of metal or metal alloy and preferably aluminium or steel into the desired L-shaped profile. The elongate outer member 2 has a generally h-shaped profile. The two opposing free ends 7 of the legs 8 of the h-shaped profile engage an upstanding web 9 of the L-shaped profile.

An arrangement indicated generally by the reference numeral 11 is provided for mechanically coupling the elongate outer member 2 and the elongate inner member 3 together. The mechanical coupling arrangement 11 applies a compressive force to an interface between the elongate outer member 2 and the elongate inner member 3.

The free edge 14 of the upstanding web 9 of the L-shaped profile has a coupling bend section 16 and the elongate outer member 2 has a correspondingly located coupled bend section 17 extending from an end of one of the legs 8 of the h-shaped profile. The coupling bend section 16 of the elongate reinforcing member 3 is formed for receiving the coupled bend section 17 of the elongate outer member 2. The dimensions of the coupling bend section 16 and the coupled bend section 17 are predetermined so that the coupling bend section 16 applies a compressive force onto the coupled bend section 17.

Advantageously, this arrangement 11 ensures that the elongate outer member 2 and the reinforcing member 3 remain firmly secured together in use. Additional mechanical fixing members such as rivets or studs are also provided at the interface between the elongate outer member 2 and the elongate reinforcing member 3.

A secondary reinforcing member 23 is provided by an elongate plate 23 mechanically coupled to a surface 24 of the outer elongate member 2 protected from the weather. Advantageously, the elongate plate 23 reduces web buckling of the elongate composite member 2 under loading. The inner elongate member 3 has a flange 25 for engaging a surface such as bricks or blocks substantially perpendicular to the upstanding web 9. The inner elongate member 3 is manufactured from steel or aluminium. The most common use of the elongate hybrid support structure is a lintel but the invention could equally be used as a support post in a building where similar technical problems associated with corrosion, thermal conductivity and structural support apply.

Referring to the drawings and now to Figure 4 there is shown a second embodiment of mechanical fixing arrangement indicated generally by the reference numeral 41 between the outer elongate member 2 and the inner elongate member 3. Two spaced apart male connecting members 42 protrude from the rearward facing surface of the upstanding web 9 of the L-shaped profile of the inner elongate member 3. These spaced apart male connecting members 42 are formed for mechanically coupling with two female members 43 on the two opposing free ends 7 of the legs 8 of the h-shaped profile of the outer elongate member 2. The free end of the upstanding web 9 of the L-shaped profile has a bulb of material 45 to stiffen the L-shaped profile improving the structural performance of the lintel. It will of course be appreciated that the invention is in no way limited to any number of male or female connecting members which are shown as exemplary only.

Referring to the drawings and now to Figure 5 there is shown a third embodiment of mechanical fixing arrangement indicated generally by the reference numeral 51 between the outer elongate member 2 and the inner elongate member 3. Two female connecting members 52 protrude from both ends of the upstanding web 9 of the L-shaped profile of the inner elongate member 3. These spaced apart female connecting members 52 are formed for mechanically coupling with two male members 53 on the two opposing free ends 7 of the legs 8 of the h-shaped profile of the outer elongate member 2. The length of the upstanding web 9 and the distance between the ends of the opposing free ends of the legs 8 are predetermined so that the female connecting members 52 apply a slight compressive force onto the male connecting members 53. The hybrid support structure 1 can be assembled by sliding male connecting members 53 into and along the elongate slots defined by the female connecting members 52. It will of course be appreciated that the invention is in no way limited to any number of male or female connecting members which are shown as exemplary only.

The features disclosed in the foregoing description or the following drawings, expressed in their specific forms or in terms of a means for performing a disclosed function, or a method or a process of attaining the disclosed result, as appropriate, may separately, or in any combination of such features be utilised for realising the invention in diverse forms thereof as defined in the appended claims.

Claims

CLAIMS1. An elongate hybrid lintel comprising a first outer elongate member mountable on the outer leaf of a cavity wall so that at least a portion of the elongate outer member is in contact with the atmosphere and a second inner elongate member mountable on the inner leaf of the cavity wall and being mechanically coupled to the first outer elongate member so that the second inner elongate member is protectable from the atmosphere in use, the outer elongate member is a composite member having a polymeric matrix reinforced with fibres and the inner elongate member is a metal or metal alloy reinforcing member attached thereto, the reinforcing member is mechanically coupled to an external portion of the elongate composite member, this coupling reducing the web buckling effect of both members, the first outer elongate member having a low thermal conductivity value compared to the thermal conductivity value of the inner elongate member to act as a thermal barrier to the ingress of cold, the elongate hybrid lintel acts as a barrier to a major pathway for thermal conductivity between the outside atmosphere and the inside of the cavity wall incorporating the elongate hybrid lintel and the inner elongate reinforcing member provides additional structural support to the elongate composite member and provides the hybrid lintel with the required resistance to web buckling.
2. An elongate hybrid lintel as claimed in claim 1, wherein the second inner elongate member is mechanically coupled to the first outer elongate member in a back to back configuration.
3. An elongate hybrid lintel as claimed in claim 1 or claim 2, wherein the elongate outer member has an open profile cross section.
4. An elongate hybrid lintel as claimed in any preceding claim, wherein the elongate outer member comprises a plurality of integral planar elements.
5. An elongate hybrid lintel as claimed in any preceding claim, wherein the elongate outer member is extruded, pultruded, moulded or folded.
6. An elongate hybrid lintel as claimed in any preceding claim, wherein the elongate inner member comprises an open profile cross section.
7. An elongate hybrid lintel as claimed in any preceding claim, wherein the elongate inner member comprises a plurality of integral planar elements.
8. An elongate hybrid lintel as claimed in any preceding claim, wherein the mechanical coupling is at an interface between the first outer elongate composite member and the inner metal or metal alloy reinforcing member..
9. An elongate hybrid lintel as claimed in any preceding claim, wherein the thermal conductivity of the outer elongate member is less than 1 W/mK.
10. An elongate hybrid lintel as claimed in any preceding claim, wherein the thermal conductivity of the outer elongate member is less than 0.5 W/mK.
11. An elongate hybrid lintel as claimed in any preceding claim, wherein the inner elongate member is produced from steel.
12. An elongate hybrid lintel as claimed in any preceding claim, wherein the inner elongate member is provided by an elongate L-shaped plate mechanically coupled to an external portion of the elongate outer member.
13. An elongate hybrid lintel as claimed in claim 11, wherein the elongate inner steel member and the outer composite elongate member are mechanically coupled together in a back to back arrangement.
14. An elongate hybrid lintel as claimed in any preceding claim, wherein the elongate composite member is provided by fiber-reinforced polymers, FRPs, carbon-fiber reinforced plastic CFRP or glass-reinforced plastic GRP.
15. An elongate hybrid lintel as claimed in any preceding claim, wherein means are provided for mechanically coupling the elongate outer member and the elongate inner member together.
16. An elongate hybrid lintel as claimed in claim 15, wherein the mechanical coupling means apply a compressive force to an interface between the elongate outer member and the elongate inner member.
17. An elongate hybrid lintel as claimed in any preceding claim, wherein additional mechanical fixing members are also provided at the interface between the elongate outer member and the elongate inner member.
18. An elongate hybrid lintel as claimed in claim 17, wherein the additional mechanical fixing members are provided by rivets, studs or intermittent tongue and slot arrangements.
19. An elongate hybrid lintel as claimed in any one of claims 12 to 18, wherein the free end of the upstanding web of the L-shaped profile has a bulb, flange or excess of material to stiffen the L-shaped profile.
20. An elongate hybrid lintel as claimed in any preceding claim, wherein the elongate outer member is mechanically coupled to the elongate inner member without additional mechanical fixing members.
21. An elongate hybrid lintel as claimed in any preceding claim, wherein the elongate outer member is mechanically coupled to the elongate inner member non-invasively without piercing or penetrating the members.
22. An elongate hybrid lintel substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.