EP0819802A2

EP0819802A2 - Structural members

Info

Publication number: EP0819802A2
Application number: EP97118158A
Authority: EP
Inventors: Malcolm Robert Wallis; David St. Quinton
Original assignee: WARD BUILDING SYSTEMS Ltd
Current assignee: Kingspan Metl Con Ltd
Priority date: 1993-08-19
Filing date: 1994-08-09
Publication date: 1998-01-21
Anticipated expiration: 2014-08-09
Also published as: GB2282162A; GB9317282D0; EP0639684B1; EP0639684A1; GB2282162B; EP0819802B1; GB9416080D0; DE69418657T2; DE69434233D1; DE69418657D1; EP0819802A3

Abstract

An elongate structural member comprising an elongate body part made of sheet metal which has been cold formed into the cross-sectional shape required and provided with an attachment portion at each end wherein at least one attachment portion comprises an attachment component (120) formed separately from said body part and fastened thereto characterised in that the body part has at least two opposed walls (102, 103) and the attachment portion (120) is within and in face-to-face relationship with the two opposed walls (102, 103) of the body part and adjacent to the opposed walls (102, 103), and connected thereto by fastening means (125), the body part comprising wall portions (21, 22, 104, 105) having edge portions extending lengthwise of the member and lying adjacent to one another, said edge portions being secured to one another by fastening means provided at least at spaced intervals along the members, the attachment portion being adapted (18) to co-operate with fasteners (38).

Description

This invention relates to an elongate structural member provided with an attachment portion at each end for attachment to other elements. Such members are widely used in buildings and the like as bracing elements, e.g. as structural ties for roof structures, trusses, stanchions and space frames. Such a structural member will hereinafter be referred to as a structural member of the kind specified.

A structural member of the kind specified has hitherto comprised a hot rolled tube provided with an attachment portion at each end. Such members made of hot rolled tube have generally been relatively expensive and heavy. They are made by cutting to length from a stock length of tube of a diameter and wall thickness which approximates as far as possible to that required for the structural strength. However, because the tube is bought in standard sizes, the tube cross-sectional dimensions cannot be tailored to each particular application. In addition, the need to cut to length from a standard length generally leads to a significant amount of waste.

In addition, the steps of welding on a cap plate to each end of the tube and a T-piece to provide the attachment portions is required followed by shot blasting and painting.

It is also known to provide an elongate structured member comprising sheet metal components which have been cold formed into the shape required to form a compound member having a generally "I" - shaped cross-section (GB 1476323).

All object of the present invention is to provide a structural member of the kind specified whereby the abovementioned disadvantages are overcome or reduced.

According to a first aspect of the present invention we provide an elongate structural member comprising an elongate body part made of sheet metal which has been cold formed into the cross-sectional shape required and provided with an attachment portion at each end wherein at least one attachment portion comprises an attachment component formed separately from said body part and fastened thereto characterised in that the body part has at least two opposed walls and the attachment portion is disposed within and in face-to-face relationship with the two opposed walls of the body part and adjacent to the opposed walls, and connected thereto by fastening means, the body part comprising wall portions having edge portions extending lengthwise of the member and lying adjacent to one another, said edge portions being secured to one another by fastening means provided at least at spaced intervals along the members, the attachment portion being adapted to co-operate with fasteners.

Preferably the body part is of a closed hollow or tubular configuration, e.g. of generally square, rectangular, circular, or other, cross-sectional shape.

The body part may comprise a unitary member having a pair of side-by-side edge portions which are secured together by said fastening means.

The side-by-side edge portions may be secured together by fastening means selected from welding, such as spot welding or other local welding; fasteners, such as screw thread fasteners, rivets, clips; crimping; clinching; or adhesive.

The edge portions may comprise two flanges secured together in side-by-side relation.

The flanges may extend outwardly relative to the interior of the closed cross-section.

Where the cross-section of the body part is rectangular, the flanges may be disposed between the ends of one side wall and preferably adjacent the middle thereof and extend outwardly thereof perpendicular to the plane of said wall.

Alternatively, the body part may be a compound member, i.e. one comprising two or more components secured together, each component affording part of the overall cross-section of the body part.

The wall portions may be wall portions of the two components.

Both where the member is a unitary member or a compound member, said fastening means may comprise means mechanically interfitting with at least one edge portion.

Such fastening means may comprise a weld or clip means interfitting with both edge portions, or a formation or formations on one edge portion interfitting with the other edge portion.

The edge portions may be provided with inturned lips so that they are each generally of U-shape in cross-section, with the bases of the two U-section portions lying adjacent one another and the limbs of the U-section portions extending away from one another. Then a, generally C-shaped, clip may engage the two edge portions.

Instead of a C-shaped clip engaging both edge portions where each edge portion has an inturned lip so as to be generally of U-section as above described, a part of its inturned lip or a wall portion adjacent such inturned lip, may be displaced to engage the inturned lip of the edge portion. Thus the requirement for separate clips may be avoided.

Whether separate clips or parts of one edge portion are used to secure the edge portions together, the security of such fastening means may be enhanced by a pressing or like operation or operations to deform the interfitting parts into a close-fitting relationship. To facilitate the carrying out of such operation or operations, one or more openings may be provided for access of a tool to the interior of the structural member. For example, if a number of fastening means are provided at spaced intervals along the length of the member, an opening may be provided adjacent each fastening means.

In the examples of members and methods of manufacture thereof according to the invention described in detail hereafter, the member may be of hollow, generally rectangular, cross-sectional shape and comprise two channel section components connected to one another. Each channel section component comprises, as viewed in cross-section, a generally flat base and two generally flat walls extending from the base substantially parallel to one another, the components being secured to one another along the free edge portions of such walls. The free edge portions of the walls may be provided with inturned lips, and the components may be held together by fastening means such as clips extending lengthwise of the member or provided at spaced intervals along the length of the member, said fastening means engaging said inturned lips. Alternatively the free edges of the walls may have cross-sectional shapes which interfit with one another and which may be pressed, crimped, or otherwise deformed to hold them in engagement with one another. Yet further alternatively the components may be welded to one another continuously or at spaced intervals along abutting free edges of the walls.

Openings may be provided at spaced intervals along the length of the member to enable access to be gained to the interior thereof for the purpose of introducing and engaging clips or to enable a tool to be entered into the interior of the member for use in a crimping or pressing operation.

The attachment component may be fastened to said body part by fasteners or by welding.

The attachment component may be of channel shape, the limbs of the channel being disposed in side-by-side relationship with two opposed walls of the body part.

Each side-by-side limb and wall may be connected together by fasteners such as by screw-threaded fasteners or rivets or crimping or may be fastened together by welding.

Reinforcing means may be provided to reinforce the connection, for example, by being disposed on the outside of the wall parts when the attachment component is disposed on the inside and between an abutment part of the fastening means and the attachment component.

The attachment component, for example the base of the channel, may be provided with means to connect the attachment component to another member.

Said means to connect the attachment part to another member may comprise at least one aperture to receive a fastener.

Closure means may be provided to close an opening in the transverse cross-section of the cold rolled member.

The closure means may comprise a member extending between the internal wall of the cold rolled member and, when provided, the external surface of the attachment component.

According to a second aspect of the invention we provide a method of providing an elongate structural member comprising an elongate body part having an attachment portion at each end, comprising the steps of cold forming sheet metal into the cross-sectional shape required for the body part such that said body part has a hollow cross-section having at least a pair of opposed walls and providing an attachment component formed separately from said body part, characterised in that it comprises the further steps of disposing said attachment component within and in face-to-face relationship with the opposed walls and adjacent to the opposed walls and connecting the attachment portion to the two opposed walls with fastening means, the elongate member having wall portions having edge portions extending lengthwise of the member and lying adjacent to one another, securing said edge portions and providing means for co-operation of said attachment portion with fasteners.

According to a third aspect of the invention we provide a building structure comprising two spaced apart elements having a structural member according to the first aspect of the invention, or made according to the second aspect of the invention extending therebetween and connected thereto in bracing relationship.

The invention will now be described by way of example with reference to the accompanying drawings, of which:-

Figure 1A and 1B are respectively a perspective view and transverse cross-sectional view of a channel section component to be used in manufacture of a structural member not according to the invention;

Figures 2A and 2B, and 3A and 3B, are views as Figure 1 of the channel section component, showing two further operations thereon in manufacture of a structural member;

Figure 4 is a side view of the component shown in Figures 3A and 3B;

Figure 5 shows a further operation in production of the member;

Figures 6 and 7 show further stages in the production of the member;

Figures 8A and 8B are views as figures 1A and 1B but showing the production of a further version of a structural member;

Figures 9A and 9B show the next stage in the production of the member of Figure 8;

Figures 10, 11 and 12 show further stages in the production of the member;

Figure 13 shows the further version in its final configuration;

Figure 14 is a perspective view of a modified version of the structural member;

Figures 15 and 16 show a further modified version of the structural member;

Figures 17 and 18 are cross-sectional views showing further structural members;

Figure 19 is a detail of the cross-section of yet another structural member;

Figures 20A and 20B are cross-sectional views of part of a still further structural member;

Figure 21 to 23 illustrate, in cross-sectional and lateral views, part of yet a further structural member;

Figure 24 is a lateral view of part of yet a further structural member;

Figure 26 is a fragmentary perspective view of a structural member embodying the invention;

Figure 27 is a side elevation of the member of Figure 26;

Figure 28 is an end view of the member of Figure 26;

Figure 29 is a perspective fragmentary view showing the connection between a structural member embodying the invention and another element;

Figure 30 is a diagrammatic elevation of a building embodying the invention showing a portal frame thereof;

Figure 31 is a fragmentary illustration showing a means for connecting flanges of the member of Figure 26; and

Figure 32 is a graphical representation showing the relationship between load bearing capacity and span of structural members embodying the invention.

Referring firstly to Figures 1A and 1B, there is shown a component which is a channel section component having a base 10 which is flat and

walls

11, 12 extending from the base, parallel to one another. The

walls

11, 12 are provided at their free edges with

inturned lips

13, 14 respectively. The intention is that two such components should be assembled with their bases parallel and spaced from one another and the edges of their

walls

11, 12 abutting to provide a structural member of rectangular hollow, i.e. tubular configuration, the two channel section components being secured together in such position by means to be described hereafter.

As a first step in the manufacture of the structural member, a coil of sheet metal is decoiled to provide a blank and then, in a pressing operation a desired length of the decoiled sheet metal is severed from the remainder of the coil and cuts or slots are formed, which in the finished member will extend from the free edge of the

walls

11, 12 to the base. Such a cut or slot is indicated at 15 in Figure 1A, a predetermined distance, e.g. 300mm, from the free end of the component. The thus form slotted blank is cold rolled, or otherwise cold formed to provide the channel shape shown in Figure 1A.

Alternatively, if desired, the sheet metal may be decoiled and cold rolled or otherwise cold formed to the desired channel shape shown in Figure 1A on a continuous basis and then cut to length after forming with suitably shaped cutting tools. Thereafter or at the same time, cuts or slots 15 are provided.

The next step is, as indicated in Figure 2B, that the

walls

11, 12, from the free end of the component to the slots as 15 in the walls, are folded to lie in face-to-face proximity to the base 10. Because of the

lips

13, 14 on the face edges of the walls, the walls remain slightly spaced from the base.

The next step is shown in Figure 3A, wherein approximately half the length of the inwardly folded walls and base of the component is subjected to a pressing operation to flatten the lips 13. As shown in Figure 3B, the walls then lie in close face-to-face relationship with the base 10. A side view of the resulting component is shown in Figure 4, wherein the end portion which has been pressed flat is indicated at 16, extending approximately half way from the free end of the component to the part thereof which has not been deformed at all. The relatively greater thickness of the portion, indicated at 17, wherein the walls of the channel section component have been folded in towards one another but not pressed flat, compared with the pressed portion 16, can be clearly seen.

The next step performed on the component thus provided is indicated at Figure 5. The

portions

16, 17 are together bent so that they remain in line with one another but are inclined to the base 10. The boundary between the

portions

16, 17 is in line with the edge of the

walls

11, 12 of the channel section component.

The next step in manufacture of the member is shown in Figure 6. The portion 16 is bent relative to the portion 17 so as to be parallel to and in line with the edges of the

walls

11, 12 of the channel section component. Holes as indicated at 18 may be drilled in the portion 16 at this stage.

Figure 7 shows a structural member comprising two components formed as shown in Figure 6 and placed with the edges of their walls as 11, 12 in abutment with one another. The portions 16 lie in close face-to-face relationship with one another. The components may be secured together by tack welding along the line indicated at 19 where the free edges of the walls abut one another, or possibly by the use of clips as described hereafter. The holes as 18 provided in the portions as 16 enable fasteners such as bolts to be passed therethrough to secure the structural member to another member or component where it is to be used. The portions 17 provide effectively for transmission of forces between the portions 16 and the hollow body portion of the structural member.

The cross-sectional shape of the hollow body part of the structural member is shown in Figure 7A, with the lips at the edges of the walls as 11, 12 abutting one another and welded thereat.

Referring now to Figures 8A and 8B of the drawings, these figures illustrate a first step in an alternative method of manufacturing a structural member from two channel-section components. A channel section component having a base 20 and

walls

21, 22 extending therefrom is illustrated, the walls having

inturned lips

23, 24 along their free edges. The component is made by cold rolling or other cold forming operation in either the sequences described in connection with the first described member. At an end portion of the component the

walls

21, 22 are completely cut away from the base 20 for a length of, for example, 300mm and then for a length of, for example, 150mm the

walls

21, 22 are cut at an inclination until the uncut edges of the walls are reached. The extreme end portion of the base 20, e.g. for a length of 150mm, is folded back on itself about a fold line 25 extending transversely of the base 20. The result of carrying out this folding step is shown in Figures 9A and 9B in perspective view and transverse cross-section, and in side view in Figure 10. It will be noted that at this stage the channel section component has the portion, indicated at 26, at its free end where the base has been folded back on itself about the transverse fold line 25 and wherein there is a double thickness of the material of the component, followed by a portion indicated at 27 wherein the side walls have been cut to provide an inclined edge extending from the base to the free edges of the uncut side walls having the

inturned lips

23, 24.

The next operation performed on the component is to fold the

portions

26, 27 together about a transverse line or region 28 on the base of the component, so that the inclined edge, 29, of each

wall

21, 22 remaining in the portion 27 is parallel to the free edge of the

uncut walls

21, 22. Adjacent the fold line 28, the material of the side walls is inwardly folded as indicated at 30 to enable this to be done. The resulting component is shown in Figure 11.

The next operation formed on the component is to reverse bend the portion 26 thereof so that it is generally in line with the free edges of the walls of the channel section component. The portion 26 may then be drilled to provide apertures 31, as shown in Figure 12.

Two components as shown in Figure 12 are then placed together such that the edges of their walls are in contact with one another and their portions 26 lie in face-to-face relationship with one another. The abutting free edges of the walls of the components may be tack welded at intervals along the length of the components to provide a structural member whose body part cross-sectional shape is a closed rectangle. Fasteners such as bolts may be passed through the apertures as 31 in the facing portions 26 of the two components to secure the structural member to another component in a building structure or the like.

Figure 14 shows a perspective view of the end region of the structural member 13, with an additional optional feature. In Figure 14, the base 20 of each of the channel section components of the structural member is stiffened by two pressed-in grooves 33 which extend lengthwise of the component in the portion 27 thereof and a short distance into the part of the base where the channel section component is not otherwise altered. Stiffening formations of other configurations could be provided, extending longitudinally or transversely of the structural member, and possibly such formations could extend throughout the entire length of the structural member.

Figures 15 and 16 are perspective views showing a further possible modification of the attachment portion of the structural member. Instead of providing two apertures in the portion 26 of each of the channel section components forming the structural member, necessitating the use of two fasteners such as bolts to secure the structural member in use, an aperture for a single fastener is provided as indicated at 34, flanked by openings 35 for receiving tongues 36 on a reinforcement member 37. Figure 16 shows a fastening bolt 38 passed through the reinforcement member.

The attachment portion is applicable to structural members whose cross-sectional shape is other than the rectangular shape above described, and to structural members other than those comprising two constituent components secured together. Figure 17 shows in transverse cross-section a structural member comprising two components 40, 41 of substantially semi-circular cross-section, abutting one another along their edges which have inturned lips as 42. The components may be welded or otherwise secured, e.g. by clips, along such edges. At an end of the structural member to provide an attachment portion, opposed portions of the components may be deformed towards one another in manner analogous to that described above.

Figure 18 shows a substantially square cross-section member, which comprises a single component only. In a succession of cold rolling or other cold forming operations, the component is provided with a base 50,

side walls

51, 52, and

top walls

53, 54 which terminate in

inturned lips

55, 56 which abut one another. Welding or clips may be used at spaced intervals along the line of such abutment to secure the

walls

53, 54 together to provide the structural member.

As above referred to, fastening means such as clips may be used instead of welding to secure two components together to form a structural member, or to secure adjacent edges of a single component together to form a structural member. A possible configuration of one such clip is shown in Figure 19. In this figure,

wall portions

60, 61 are shown with inturned lips 62, 63 at their edge portions, which are generally of U-shape in cross-section and of which the bases abut one another. A clip 64 of resilient material comprises a base 65 which extends across the two lips 62, 63, and

portions

66, 67 which engage behind the lips 62, 63 to hold the

walls

60, 61 together.

If such clips are used in a structural member, provided at spaced intervals along the length of the member, apertures may be provided in the member to enable access to be gained to the interior thereof for the purpose of fitting such clips.

Referring now to Figures 20A and 20B, these show a further possible arrangement of clip for securing adjacent edge portions of a single component, or of two components, together to form a structural member.

Wall portions

70, 71 of the component or components are illustrated, with inturned lips at their free edge portions such that the edge portions are generally of U-shape in cross-section, with

base portions

72, 73 of the U-shapes lying adjacent one another and

limbs

74, 75 thereof extending away from one another. A generally C-shaped clip member 76 made of a malleable metallic material engages the

limbs

74, 75, and subsequent to such engagement is subjected to a crimping or pressing operation so that it is deformed to the configuration shown in Figure 20B. When thus deformed, the clip member closely embraces the

limbs

74, 75 and a portion of the clip member, indicated at 77, extends partially into the region where the

limbs

74, 75 diverge from the

portions

72, 73. Thus a secure mechanical connection is provided between the adjacent edge portions of the

walls

70, 71 of the component or components.

To enable access to be gained to the clip member 76 for carrying out such deformation thereof, an opening or aperture may be provided in the structural member adjacent the member 76. If fastening members such as 76 are provided at spaced intervals along the structural member, a respective aperture may be provided adjacent each member, to permit a pressing tool to be introduced to the interior of the member.

Instead of clips such as 64 or 76 being provided at spaced intervals along a structural member, elongate fastening members of similar or analogous cross-sectional shape to such clips could be provided, extending along all or most of the length of the structural member.

Instead of separate fastening means, such as clips as above described, being used for securing adjacent edge portions of one or more components to one another, a fastening formation or formations may be provided at one edge portion and arranged to engage the other edge portion. One possible such fastening formation is illustrated in Figures 21 to 23. Figure 21 shows

wall portions

80, 81 with

respective edge portions

82, 83 which are inturned lips so that the edge portions are of U-shape, as previously shown in Figure 20. Adjacent its edge portion, one of the

wall portions

80 or 81, in this case the wall portion 80, is provided with a pressed-out tongue portion 84 which extends generally perpendicular to the edge portion, remaining integrally secured to the wall portion at its end 85 nearest the edge portion.

To secure the two edge portions together, the tongue 84 is bent downwardly as shown in Figure 23A to a generally C-shaped configuration to engage beneath the inturned lip constituting the other edge portion 83. Finally a pressing operation further deforms the tongue 84 and the two

edge portions

82, 83, to the configuration shown in Figure 23B to provide a secure connection. Such deformation of the tongue 84 requires the introduction of a tool into the interior of the structural member, either through the aperture left by the pressing-out of the tongue 84 or through another aperture provided in the vicinity thereof.

An edge portion of a wall may itself be arranged to provide a formation engageable with another edge portion to secure two components or parts of a component together. Figure 24 shows a lateral view of part of a structural member comprising two

wall portions

90, 91 of a component or components, with

edge portions

92, 93 respectively lying adjacent one another, the two edge portions being of U-shaped configuration as above described. To provide a fastening formation, at two points 94, 95 spaced from one another lengthwise of the member the inturned lip of one edge portion may be sheared through, whilst the inturned lip of the other edge portion is partially cut and removed. Then, as shown in Figure 25A or 25B, the lip 96 on the component 90 between the points 94, 95 is deformed from its original position (shown shaded) to engage the remaining edge portion 97 of the component 91. Such an arrangement may be provided at a number of positions spaced along the length of the structural member.

Referring now to Figures 26 to 28, a substantially square cross-section body part is indicated generally at 100 and is again made from a coil of sheet material by cold rolling or other cold forming operation in either of the sequences described in connection with the first embodiment to the configuration shown in Figure 1 so as to have a base 101,

side walls

102, 103,

top walls

104, 105 having along edge portions thereof out-turned lips or

flanges

106, 107 which extend perpendicular to the

top walls

104, 105.

The

flanges

106, 107 are secured to one another by fastening means which, in the present example comprises tack or spot welding but may be any other suitable fastening means such as other local welding or continuous welding or fasteners such as screw-threaded fasteners, rivets, clips, by crimping, clinching or by adhesive or by any other desired manner.

One preferred alternative to tack welding is to act upon one of the flanges with a punch substantially perpendicular to the surface of the flange and the other flange having a die on the opposite side thereof of a re-entrant configuration so that the punch forces metal of the two flanges into the die to form a rivet type or crimped, clinched fastening, the die has movable parts to enable removal thereof from the thus formed fastening. Such an arrangement is shown in cross-section in Figure 31 and is known as "Tog-L-Loc".

Such fastening operation is performed at a plurality of positions along the length of the

flanges

106, 107.

Alternatively, any of the previously described fastening means such as clips etc. as used in connection with any of the previous members may be provided.

The body part member 100 is provided with an attachment component 120 which, in the present example is of channel configuration comprising a base 121 and spaced parallel

upstanding beams

122, 123 which are perpendicular to the base 121. The channel shaped attachment member 120 is made in any convenient manner but again is preferably made by a cold forming operation such as cold rolling from a blank cut from a coil of strip material as described hereinbefore, or if desired, the strip may be cold formed to channel shape and then cut to length.

A pair of apertures 124 are provided in the base of the channel in any convenient manner, preferably during the cutting to length operation and, in addition, apertures, not shown, are formed in the

limbs

122, 123 to receive bolts 125 which extend through apertures, not shown in the

side walls

102, 103 of the cold formed member 100. Again these apertures in the

walls

102, 103 are preferably formed during the cutting to length operation prior to cold forming.

The bolts 125 have a generally rectangular reinforcing plate 126 disposed beneath their heads 127 so that the relatively thin material of the

side walls

102, 103 is clamped by the bolts between the plate 126 and the associated

wall

122, 123.

By virtue of having a separate attachment component 120, the attachment component may be made of material of appropriate composition and thickness so as to render it capable of accommodating the stresses imposed in use when it is connected to components to be braced. In addition by providing the reinforcing plates 126, the connection of the attachment component to the cold rolled box section member 100 is also rendered capable of accommodating the necessary stresses. At the same time the material of which the box section member is made can be relatively thin whilst still providing adequate strength.

In general the box section may be provided with adequate strength by making the box section member of relatively thin gauge material compared with that necessary for the attachment portion and therefore considerable saving in cost of materials and weight can be achieved by making the attachment portion as a separate component of relatively greater thickness than the material of the main part 100 of the structural element.

For example a member embodying the invention may be of the following dimensions where a, b and c are the dimensions illustrated in Figure 28.

Section	Wall Thickness (mm)	Dimensions (mm)
		a	b	c
1	1.5	82	18	50
2	1.5	100	50	75
3	2.0	100	50	75
4	2.4	100	50	75
5	3.2	100	50	75

Figure 32 is graphical representation showing the ultimate compression capacity in kilo Newtons plotted against span in metres of members embodying the invention and having the dimensions indicated above.

It will be seen that, for example, in the case of Section 1, the strength of the member up to a span of 4 metres is limited by the strength of the attachment portion whereas in the case of Section 2, the strength is limited by the strength of the attachment portion tip to a span of about 6.75 metres since the box section member of Section 2 is stronger than that of Section 1 by virtue of its greater dimensions, a, b and c.

As can be seen from Figure 32,

Sections

3, 4 and 5 are of the same dimensions a, b and c as Section 2, but are of greater wall thickness and hence of greater strength than that of

Sections

1 and 2.

In the present example, the channel shape attachment portions for Sections 1 to 5 are of two sizes. The attachment portion for Section 1 has a wall thickness of 6mm and the limbs of the channel (dimension 'd' in Figure 28) are 64mm. The attachment portions for each of

Sections

2, 3, 4 and 5 have a wall thickness of 8mm and a dimension 'd' of 100mm.

Referring now to Figure 29 a member as described with reference to Figures 26 to 28 is indicated generally at 100 and is shown attached to a lug 130 welded, as shown at 131 to a web 132 of an I-section rafter 133. Bolts, not shown are provided to bolt the base of the attachment component 120 to the lug 130 through the apertures 124 of the component 120 and corresponding apertures 134 of the lug 130.

Figure 30 illustrates a typical portal frame 140 of a steel frame building provided with a plurality of lugs 130 to each of which pairs of members embodying the invention are bolted as described hereinbefore so as to brace, in a zig-zag manner, the portal frame 140 relative to an adjacent frame disposed within the building. If desired, the bracing may also be provided between stanchions of the portal frame anti corresponding stanchions of the next adjacent frame:

The structural members embodying the invention overcome the disadvantages discussed hereinbefore in connection with previously made hot rolled members in that they are made from material cut to length without waste and avoid the need for extensive welding operations followed by shot blasting and painting since the sections made be made from galvanised steel. In addition, the sections are of lighter weight. For example, in the case of the embodiment described with reference to Figures 26 to 32 when used in a 30 metre span portal building 6.5m to the eaves anti with a 6° roof slope with gable posts spaced at 6m intervals and assuming a wind loading of 45m per second and a ground reference of 2b, a total of twelve brace members embodying the invention are required having a total weight of about 560kg compared with a total weight of about 1060kg for conventional hot rolled circular hollow section bracing members.

If desired, in all embodiments a closure member such as a foam plastics/rubber pad may be provided at and to close the open end of the tubular body to prevent the ingress of insects or detritus.

The features disclosed in the foregoing description, or the following claims, or in the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for 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.

Claims

An elongate structural member comprising an elongate body part made of sheet metal which has been cold formed into the cross-sectional shape required and provided with an attachment portion at each end wherein at least one attachment portion comprises an attachment component (120) formed separately from said body part and fastened thereto characterised in that the body part has at least two opposed walls (102, 103) and the attachment portion (120) is within and in face-to-face relationship with the two opposed walls (102, 103) of the body part and adjacent to the opposed walls (102, 103), and connected thereto by fastening means (125), the body part comprising wall portions (21, 22, 104, 105) having edge portions extending lengthwise of the member and lying adjacent to one another, said edge portions being secured to one another by fastening means provided at least at spaced intervals along the members, the attachment portion being adapted (18) to co-operate with fasteners (38).
A member according to Claim 1 wherein the body part is of a closed hollow or tubular configuration.
A member according to Claim 1 or Claim 2 wherein the body part comprises a unitary member (100) having a pair of side-by-side edge portions which are secured together by said fastening means.
A member according to Claim 3 wherein the edge portions comprise two flanges (106, 107) secured together in side-by-side relation.
A member according to Claim 4 wherein the flanges (106, 107) extend outwardly relative to the interior of the closed cross-section (100).
A member according to Claim 1 or Claim 2 wherein the body part is a compound member, comprising two or more components (10) secured together, each component affording part of the overall cross-section of the body part.
A member according to any one of Claims 1 to 6 wherein said fastening means comprises a weld or means mechanically interfitting with at least one edge portion.
A member according to Claim 7 wherein said fastening means comprises clip means (76) with both edge portions, or a formation or formations on one edge portion (96) interfitting with the other edge portion (97).
A member according to Claim 8 wherein a pressing or like operation or operations is performed to deform the interfitting parts into a close-fitting relationship.
A member according to any one of the preceding Claims wherein the attachment components are fastened to the body part by fasteners or by welding.
A member according to any one of the preceding Claims wherein the attachment component is of channel shape, the limbs of the channel being disposed in side-by-side relationship with two opposed walls of the body part.
A member according to any one of the preceding Claims wherein reinforcing means (126) are provided to reinforce the walls (102, 103) of the body part.
A member according to any one of the preceding Claims wherein the attachment component, is provided with means to connect the attachment component to another member.
A member according to Claim 13 wherein said means to connect the attachment part to another member may comprise at least one aperture to receive a fastener.
A method of providing an elongate structural member comprising an elongate body part having an attachment portion at each end, comprising the steps of cold forming sheet metal into the cross-sectional shape required for the body part such that said body part has a hollow cross-section having at least a pair of opposed walls and providing an attachment component formed separately from said body part, characterised in that it comprises the further steps of disposing said attachment component within and in face-to-face relationship with the opposed walls and adjacent to the opposed walls and connecting the attachment portion to the two opposed walls with fastening means, the elongate member having wall portions having edge portions extending lengthwise of the member and lying adjacent to one another, securing said edge portions and providing means for co-operation of said attachment portion with fasteners.
A building structure comprising two spaced apart elements (140) having a structural member according to any one of Claims 1 to 14 or made according to Claim 15 extending therebetween and connected thereto in bracing relationship.