PROFILES

Abstract

An elongate profile (1) having a first portion (2) and a second portion (3), the first and second portions (2, 3) being joined together at a first joining portion (JP1), the first and second portions (2, 3) being non collinear, the joining portion (JP1) comprising an array of raised or rebated formations (10a), each formation extending across the joining portion (JP1) in a direction which is non-parallel to the principal axis of the profile and flat lands being provided between successive formations in an array (10A) and the pitch (P) between successive formations in an array being from 2 to 20 times, for example from 5 to 15 times, the thickness (G) of the flatlands.

Claims

1-26. (canceled)

27. An elongate profile having a first portion and a second portion, the first and second portions being joined together at a first joining portion, the first and second portions being non collinear or non coplanar, the joining portion comprising an array of raised or rebated formations, each formation extending across the joining portion in a direction which is non-parallel to the principal axis of the profile and flat lands being provided between successive formations in said array and the pitch (P) between successive formations in said array being from 2 to 20 times the thickness (G) of the flat land.

28. A profile according to claim 27, further comprising a third portion and wherein the third portion is joined to the first portion at a second joining portion and wherein the second joining portion comprises an array of embossed formations.

29. A profile according to claim 28, wherein the first and third portions are non collinear or non coplanar.

30. A profile according to claim 28, wherein the first, second and third portions, and the first and second joining portions form a channel section.

31. A profile according to claim 27, wherein one or more of the raised or rebated formations in said array is elongate.

32. A profile according to claim 27, wherein one or more of the raised or rebated formations in said array has a principal axis which is inclined to the principal axis of the profile.

33. A profile according to claim 27, wherein one or more of the raised or rebated formations in said array is rectangular.

34. A profile according to claim 34, wherein the first portion comprises in sectional view castellations.

35. A profile according to claim 27, wherein at least one of the first and second portions having an array of projections and depressions, the depressions on one side of said at least one of the first and second portions corresponding to projections on the other side of said at least one of the first and second portions.

36. A profile according to claim 27, wherein at least a part of the first or second portion is embossed, knurled or work hardened.

37. A profile according to claim 27, wherein at least one of the formations in said array has a form depth F of between 0.5 and 4 times the base gauge G of the material.

38. A profile according to claim 27, wherein the pitch P of the formations in said array is from 5 to 15 times the base gauge G of the material.

39. A profile according to claim 27, wherein each formation in said array has a width W and the width W of a formation is from 0.2P to P, wherein P is pitch P of the formations in said array.

40. A profile having a first portion, a second and a third portion extending from respective first and second sides of the first portion at a respective first and second joining portion, a first array of elongate raised formations being located around the first joining portion and a second array of elongate raised formation being located around the second joining portion, each of the formations in the first and second arrays being separated by a flat land having a thickness G and the pitch (P) between successive formations in each of said arrays being from 2 to 20 times the thickness (G) of the flat land.

41. A profile according to claim 40, wherein the form depth F of each formation in said first and second arrays is between 0.5 and 4 times the base gauge G of the material.

42. A profile according to claim 40, wherein each formation in said first and second arrays has a width W and the width W of a projection is from 0.2P to P.

43. A profile according to claim 40, wherein at least one of the first, second and third portion comprises an array of projections and depressions across its surface, the projections on one side of the surface corresponding to depressions on the other side of the surface.

44. A pair of tools for forming a pattern on sheet material, the first tool comprising a first forming portion for forming at least part of a first pattern on a sheet material and a second forming portion for forming at least part of a second pattern on the sheet material, the first forming portion comprising a first array of projections and the second forming portion comprising a second array of projections, the second tool comprising a third forming portion for forming at least part of said first pattern on the sheet material and a fourth forming portion for forming at least part of said second pattern on the sheet material, the third forming portion comprising a third array of projections and the fourth forming portion comprising an array of rebates, the second forming portion and the fourth forming portion being co-operable to emboss a pattern corresponding to the respective array of projections and rebates on the sheet material and the first and third forming portions are co-operable to cold work harden the sheet material to form an array of projections.

45. A pair of tools according to claim 44, wherein the tools are mounted for contra rotation and, when so mounted, the first and third forming portions intermesh such that as the first and second tools rotate the first array of projections engages gaps between the third array of projections and vice versa.

46. A method of treating sheet material, the method comprising passing sheet material between cooperating first and second tools, each tool having a first portion for embossing sheet material in a first region and a second portion for shaping the sheet material in a second region, and embossing the sheet material in the first region whilst simultaneously cold work hardening the sheet material in the second region.

Description

[0061] In order that the invention may be more fully understood it will now be described, by way of example only and with reference to the accompanying drawings, in which:

[0062] FIG. 1 is an isometric view of a profile according to the invention;

[0063] FIG. 1A is an end elevation of the profile of FIG. 1;

[0064] FIG. 1B is an enlarged view of a part of the profile of FIG. 1;

[0065] FIG. 2 is an isometric view of a further embodiment of the invention;

[0066] FIG. 2A is an end elevation of the profile of FIG. 2;

[0067] FIG. 2B is an enlarged view of a part of FIG. 2;

[0068] FIG. 2C is a plan view of the profile of FIG. 2;

[0069] FIG. 3 is a plan view of a box section formed from profiles according to the invention;

[0070] FIG. 4 is a schematic diagram of forming apparatus according to the invention

[0071] FIG. 5 is a photograph of embossing equipment according to the invention;

[0072] FIG. 6 is a perspective view of apparatus according to the invention;

[0073] FIG. 6A is a detailed view of part of FIG. 6;

[0074] FIG. 6B is a detailed view of a further part of FIG. 6;

[0075] FIG. 7 is a plan view of a profile according to the invention;

[0076] FIG. 7A is a sectional view through a part of the profile of FIG. 7;

[0077] FIG. 7B is a magnified view of a part of the profile of FIG. 7;

[0078] FIG. 7C is a photograph of a section of a part of a profile of FIG. 7;

[0079] FIG. 8 is a schematic view of a part of a wall incorporating a profile of FIG. 1;

[0080] FIG. 8A is a portion of the wall of FIG. 8

[0081] FIGS. 9A to 9C show a test rig for conducting the test of Example 4 with an isometric view of the test rig (FIG. 9A), front elevation of the test rig (FIG. 9B) and side elevation of the test rig (FIG. 9C);

[0082] FIG. 10 shows a test rig for conducting the test of Example 5; and

[0083] FIGS. 11A and 11B show graphs of experimental data of Example 6 and Comparative Example 6A.

[0084] Referring to FIGS. 1, 1A and 1B there is shown a profile 1. The profile 1 of the form shown is termed a C profile. The profile 1 has a base portion 2 from which extends a pair of parallel side portions 3, 4. The side portions 3, 4 respectively terminate with in-turned flanges or ledge portions 5, 6 which overlie the base portion 2.

[0085] The base portion 2 has a neutral plane, designated P in the drawings. The base portion 2 comprises a central region 20 and a pair of outboard regions 21. Between the central region 20 and each outbound region 21 is a rebated portion 22 to provide, when looking along the profile (see FIG. 1A), a castellated effect.

[0086] The side portions 3, 4 each have an elongate inwardly directed rib 30, 40 respectively extending along the length thereof.

[0087] The first side portion 3 is of greater area, i.e. it extends further from the base portion 2 in a direction orthogonal to the neutral plane P (and to the direction of the principal axis A of the profile 1), than does the second side portion 4. Also the rib 30 of the first side portion 3 is smaller than the rib 40 of the second side portion 4. The apex 31 of the rib 30 is positioned the same distance from the base portion 2 than is the apex 41 of the other rib 40. The reason for the differences will become apparent. It is also within the scope that the ribs are position at slightly different positions with respect to the neutral plane P and/or with respect to one another.

[0088] As a consequence of the different extensions of side portions 3, 4 from the base portion 1, the respective ledge portions 5, 6 are parallel to each other (and to the neutral plane P) but are located at different distances (in a direction orthogonal to the neutral plane P) from the base portion 2.

[0089] At each position where a portion 2, 3, 4, 5, 6 joins to another portion (2, 3, 4, 5, 6) there is a joining portion JP1, JP2, JP3, JP4. The material in the region of each joining portion JP1-4 may be, overall, thinner than in the adjacent portions 2-6. In the above and below description a ‘joining portion’ is intended to mean a part which joins two elements of a profile the planes of which elements describe an angle therebetween of, or greater than, 30° (in the embodiment of FIG. 1 the angle is at or about 90°), whereas a ‘join’ is intended to mean a part which joins two elements of a profile, the planes of which describe an angle therebetween of less than 30°, for example the two elements may be parallel but non-co-linear or non-co-planar.

[0090] Located as a longitudinal array 10 along each joining portion JP1-4 is a series of formations, namely outwardly extending protuberances or projections, 10a-d respectively. As is best seen in FIG. 1B, each one of the substantially identical projections 10e of the series of projections 10a-d (a part of series 10c is shown) is rectangular with parallel sides 10f and with a principal axis 10g orthogonal to the principal longitudinal axis A of the profile 1 and with rounded ends 10h.

[0091] As shown, each of the projections 10e extends outwardly from the surface of each of the joining portions JP1-4 (i.e. the projections 10 radiate or extend away from one another) and is curved around the respective bend in the profile 1 (that is at the respective joining portion JP1-4) such that each projection 10e is substantially L-shaped. Between successive projections are flat lands FL. It will be appreciated that each of the central region 20 and rebated portions 22 and outboard regions 21 are non-collinear or non-coplanar. It is within the scope of this invention, that a profile 1 comprising ‘joins’ and/or ‘joining portions’ wherein one, some, both or all the joins and/or joining portions comprise one or more embossed projections will fall within the scope of the invention.

[0092] The surface of one or more of the portions 2, 3, 4, 5, 6 may be work hardened, embossed or knurled. It is preferred that at least one, some and most preferably all of the surface of the portions 2, 3, 4, 5, 6 are cold rolled and work-hardened, for example using a method set out in one of our patent applications GB2450765A, EP0891234A.

[0093] For the avoidance of doubt and as would be appreciated by the skilled person, the term ‘cold working’ (also known as ‘cold work hardening’) as used herein refers to the deformation of metal plastically at a temperature below its lowest recrystallisation temperature, where strain hardening occurs as a result of such permanent deformation. In addition, the term ‘embossing’ as used herein refers to the operation of raising a design or form above and/or below the surface of a component by means of high pressure effected by pressing or squeezing action, and includes debossing.

[0094] It is known that embossing and cold work hardening are distinct techniques. Embossing involves compressing material, in this case sheet metal, between two tools (e.g. rolls) to reduce its thickness beyond its ultimate tensile strength into the purely plastic range; it is a compression process which uses significant force to squeeze the material between two tools (e.g. rolls), one of which has a projection (or rebate) and the other has a rebate (or projection) whereby the pattern on the tool (e.g. roll) is transferred to the material. In contrast, work hardening by cold roll forming involves plastic strain hardening a material by locally stretching the material without compression. It is conveniently achieved in our above-identified patent applications by using pairs of matched male forming rolls with the teeth of one of the rolls extending (as the rolls rotate) into gaps between teeth on the other roll. Clearly, the skilled person knows and recognises that the techniques are distinct and generate different effects. For example, because of the thinning that occurs with embossing processes embossing is not usually used to work harden or strengthen a sheet material. Other surface effecting processes include knurling and coining. Knurling involves pressing a series of sharp serrations on a hardened steel roller into a work-piece, effectively displacing the material sideways using serrations or projections, rather than pushing projections through the other side of the sheet. This has the effect of roughening the surface, for example to increase surface roughness/friction coefficient, but does not materially alter the strength or stiffness of the work-piece (in some cases it may weaken the material).

[0095] Because one side portion 3 extends further away from the base portion 2 than the other side portion 4 it is easy and convenient to make a box section, as will be described below.

[0096] Referring now to FIG. 2 and FIGS. 2A, 2B and 2C there is shown a further profile 1′ of the invention.

[0097] The profile 1′ has a base portion 2′ from which extend a pair of parallel side portions 3′, 4′. The side portions 3′, 4′ respectively terminate with in-turned ledge portions 5′, 6′ which overlie the base portion 2′.

[0098] The base portion 2′ has a neutral plane, designated P′ in the drawings. The base portion 2′ comprises a central region 20′ and a pair of outboard regions 21′. Between the central region 20′ and each outbound region 21′ is a rebated portion 22′ to provide, when looking along the profile 1′ (see FIG. 2A) a castellated effect.

[0099] The side portions 3′, 4′ each have an elongate inwardly directed rib 30′, 40′ respectively extending along the length thereof.

[0100] The first side portion 3′ is of greater area, i.e. it extends further from the base portion 2′ in a direction orthogonal to the neutral plane P′ (and to the direction of the principal axis A′ of the profile 1′), than does the second side portion 4′. Also the rib 30′ of the first side portion 3′ is smaller than the rib 40′ of the second side portion 4′. The apex 31′ of the rib 30′ is positioned slightly further away from the base portion 2′ than is the apex 41′ of the other rib 40′. The reason for the differences will become apparent.

[0101] As a consequence of the different extensions of side portions 3′, 4′ from the base portion 1′, the respective ledge portions 5′, 6′ are parallel but are located at different distances (in a direction orthogonal to the neutral plane P′) from the base portion 2′.

[0102] At each position where a portion 2′, 3′, 4′, 5′, 6′ joins to another portion (2′, 3′, 4′, 5′, 6′) there is a joining portion JP1′, JP2′, JP3′, JP4′. The material in the region of each joining portion JP1′-4′ may be, overall, thinner than in the adjacent portions 2′-6′.

[0103] Located as a longitudinal array 10′ along each joining portion JP1′-4′ is a series of inwardly extending protuberances or projections 10a′-d′ respectively. As is best seen in FIG. 2B, each one of the substantially identical projections 10e′ of the series of projections 10a′-d′ (a part of series 10c′ is shown) is rectangular with parallel sides 10f and with a principal axis 10g′ orthogonal to the principal longitudinal axis A′ of the profile 1′ and with rounded ends 10h′.

[0104] As shown, the projections 10e′ extend inwardly from the surface of each of the joining portions JP1′-4′ and are curved around the bends in the profile 1′ (that is at the respective joining portion JP1′-4′) such that each projection 10e′ is substantially L shaped. Between successive projections are flat lands FL′.

[0105] As well as projections 10e′ in the joining portions JP1′-4′, there is also an array projections 10e′ along each of joins J1′-4′ between each of the central region 20′ and rebated portion 22′ and between each outboard region 21′ and its adjacent rebated portion 22′. It will be appreciated that each of the central region 20′ and rebated portion 22′ and outboard region 21′ and rebated portion 22′ are non-collinear or non-coplanar. It is within the scope of this invention, that a profile comprising ‘joins’ and/or ‘joining portions’ wherein both or either the joins and/or joining portions comprise one or more embossed projections will fall within the scope of the invention.

[0106] As well as having the embossed rebates 10′, substantially the entire surface of the side portions 3′ and 4′ has been knurled KP, to provide a surface roughening effect on the outermost surface of each side portion 3′, 4′. Alternatively, the or any of the portions 2, 3, 4, 5, 6 could, preferably, have been work hardened in accordance with our above-identified patent applications.

[0107] Whilst in FIG. 1 all of the projections 10e are outwardly facing and are only provided at the joining portions JP1-4, it will be appreciated that projections 10e may be inwardly directed and may be provided at the joins between rebated portions 22 and central 20 and/or outboard regions 21, as is shown in FIG. 2D. Also, in each embodiment (FIG. 1, FIG. 2) fewer arrays of projections 10 could be present. Moreover, in each of the embodiments of FIG. 1 or 2, some or all of the projections 10e, 10e′ may extend inwardly or outwardly and some or all of the others outwardly or inwardly. For example, the projections 10e in an array 10 may alternate between inwardly and outwardly directed projections. Alternatively or additionally, some or all of the projections 10e of a first array may extend inwardly and some or all of those of a second array may extend outwardly.

[0108] Referring to the profile of FIG. 2 (although equally applicable to the profile 1 of FIG. 1) because one side portion 3′ extends further away from the base portion 2′ than the other side portion 4′ it is easy and convenient to make a box section 15′, as shown in FIG. 3. With two profiles 1a′, 1b′ brought into facing and abutting relations the longer side portion 3a′ of the first profile 1a′ is able to embrace the shorter side portion 4b′ of the second profile 1b′, and vice versa. In this configuration the rib 30a′ of the first side portion 3a′ of the first profile 1a′ projects into the space defined by the rib 40b′ of the second side portion 4b′ of the second profile 1b′. Because of the array of projections 10a′-d′ on each profile 1a′, 1b′ and the engaging ribs 30a′, 40b′ and 30b′, 40a′ there is significant interference between engaged profiles 1a′, b′, thereby ensuring that profiles 1a′, 1b′ are securely held together. Additionally or alternatively, because the larger side portions 3a′, 3b′ embrace the smaller side portions 4b′, 4a′ and/or because the profiles 1a′, 1b′ snugly engage, the so-formed box section is robust and will not slip longitudinally with respect to one another.

[0109] The profile 1, 1′ of the invention is formed from flat sheet material, typically supplied from a coil. Reference is made to FIG. 4 wherein sheet material 100 supplied from a coil (not shown) is passed through a series of roll pairs 200, 220, 230, 240. Usually there will be more than four pairs, and, for forming the specific profile 1 of FIG. 1, one would expect between 12 and 15 pairs of rollers, for example 14 pairs. For forming an I-beam one might expect 18 roller pairs.

[0110] The sheet material 100 is first passed through a pair of embossing rollers 200 comprising a first roll 180 and a second roll 190 contra rotating about respective axes 201, 202. The embossing roller pair 200 causes the sheet material 100 to become embossed to provide an embossed sheet material 101, which may be subsequently shaped to form a profile 1 of the invention.

[0111] Passage of the embossed sheet material 101 through successive pairs of rollers 220, 230, 240 causes the castellations (20, 21) on the base portion 2, elongate ribs 30, 40 and folds the side portions 3, 4, and ledge portions 5, 6.

[0112] As can be seen, the rollers 220, 230, 240 successively bend the sheet material 101 in the region of the joining portions JP 1-4 to form the embossed projections into L-shaped projections 10e.

[0113] Whilst the above description describes the manufacture of a profile 1 with plain surfaces 2, 3, 4 it is possible to provide a profile with one or more knurled portions (as per the profile 1′ shown in FIG. 2) or with embossed and/or work hardened portions. If the knurled profile is required, the knurling operation may take place upstream or downstream of the embossing rolls 200 or, alternatively, the parts of the roll 180 (and/or 190) may be provided with knurling sections outboard of the embossing sections.

[0114] If it is desired to provide a profile having work hardened portions, for example work hardened in accordance with one of the methods disclosed in one of GB2450765A or EP0891234A, it is possible to work harden the sheet material upstream or downstream of the embossing roll pair 200. However, we prefer, for reasons of efficiency, to emboss and work harden the sheet material 100 simultaneously.

[0115] Reference is made to FIG. 5, which shows a simultaneous embossing and work hardening roll pair 200a. The first, upper (as shown), roll 180a carries plural (four shown) circumferential series of radial rebates 181a distributed along the circumferential surface 182a of the roll 180a. The second, lower, roll 190a has equivalent plural circumferential series of projections 191a, correspondingly distributed such that the rebates 181a and projections 191a cooperate in use.

[0116] Passage of the sheet material 100 between the matched rolls 180a, 190a causes the projections 191a to emboss the sheet material 100 by stretching and forcing sheet material into the rebates 181a on the upper roll 180a, thereby forming a flat sheet material 101a having plural columns of embossed projections 110a, one column corresponding to each circumferential series of rebates 181a on the first roll 180a and corresponding series of projections 191a on the second roll 190a.

[0117] Out board of the embossing regions 181a, 191a, each roll 180a, 190a carries a series of male forming elements in respective work-hardening regions 182a, 192a. The male formers on one roll intermesh with those of the other roll such that as the rolls 180a, 190a contra-rotate the male formers of one roll extend into spaces between the male formers on the other roll, and vice versa. The work hardening may be undertaken in accordance with one or more methods described in our earlier patent applications, GB2450765A or EP0891234A, and preferably in accordance with EP2091674.

[0118] In order to help with the alignment of the rolls 180a, 190a, one roll (e.g. 180a) may be provided with peripheral extension portions (e.g. as indicated at 183a) which are able to travel in peripheral matched rebate portions (e.g. as indicated at 193a) on the other roll (e.g. 190a).

[0119] The sheet material may be formed into a C-profile, for example as shown in relation to FIG. 1.

[0120] FIG. 6 and FIGS. 6A and 6B show details of embossing rolls according to the invention which are capable of embossing and work hardening sheet material as it passes between them.

[0121] Referring first to FIG. 6, there is shown a first roll 180b having two embossing regions 181b comprising a series of circumferential rebates. Outboard of the embossing region 181b, the roll 180b has three work hardening regions 182b comprising a series of male forming elements. There is also shown a second roll 190b having two embossing regions 191b comprising a series of circumferential projections. Outboard of the embossing region 191b, the roll 190b has three work hardening regions 192b comprising a series of male forming elements.

[0122] Referring now to FIG. 6A, there is shown a section of the first roll 180b, including a part of an embossing region 181b and a work hardening region 182b. In the work hardening region 182b the roll 180b has a base or root 185b from which upstands plural male forming members 186b. The roll 180b has a circumferential direction C′ and a transverse direction T′ and rows 187b of male forming members 186b are provided which extend in a direction D′ between the circumferential direction C′ and the transverse direction T′.

[0123] The embossed region 181b comprises a band having a surface 183b which is raised with respect to the root 185b of the roll 180b (i.e. the surface 183b is radially further from the centre of the roll 180b than the root 185b). Extending into the surface 183b are a series of rebates 184b, each being rectangular with parallel sides extending in the transverse direction T′ and with rounded ends.

[0124] Referring now to FIG. 6B, there is shown a section of the second roll 190b, including a part of an embossing region 191b and a work hardening region 192b. In the work hardening region 192b the roll 190b has a base or root 195b from which upstands plural male forming members 196b. The roll 190b has a circumferential direction C″ and a transverse direction T″ and rows 197b of male forming members 196b are provided which extend in a direction D″ between the circumferential direction C″ and the transverse direction T″.

[0125] The embossed region 191b comprises a band having a surface 193b which is raised with respect to the root 195b of the roll 190b (i.e. the surface 193b is radially further from the centre of the roll 190b than the root 195b). Extending from the surface 193b are a series of projections 194b, each being rectangular with parallel sides extending in the transverse direction T′ and with rounded ends.

[0126] In use, the rolls 180b, 190b are aligned such that the male formers 186b of the first roll 180b intermesh with male formers 196b of the second roll 190b and the projections 194b of the second roll at least partially extend into the rebates 184b of the first roll 180b.

[0127] When sheet material is passed between the rolls 180b, 190b the sheet material is embossed between the cooperating embossing regions 181b, 191b and work hardened in the cooperating work hardening regions 182b, 192b. In the embossing regions, the sheet material is gripped between the facing surfaces 183b, 193b and stretched in the region of the projections 194b and rebates 184b to assume the shape of the projections 194b. In each of the work hardening regions the sheet material does not contact the root 185b, 195b of either roll 180b, 190b but is locally stretched to work harden the material by action of the intermeshing male members 182b, 192b, that is to say there is no compression of the sheet material between a projection 182b (or 192b) on one roll 180b (or 190b) and the root 195b (or 185b) of the other roll 190b (or 180b). In other words, when the tools intermesh there is a clearance between the peaks of the projections (e.g. 182b) on one roll (e.g. 180b) and the root (e.g. 195b) on the other roll (e.g. 190b) which is equal to, or preferably greater than the base gauge of the sheet material to be processed. In contrast, in the embossing regions, there is no such clearance. It is by virtue of the respective configurations (i.e. that the surface 183b of the band is raised with respect to the root 185b, and that the surface 193b of the band is raised with respect to the root 195b) that embossing is effected in that region and that because there is adequate clearance between the facing rollers in the cold work hardening regions that the sheet material is work hardened in those regions.

[0128] It is hugely advantageous to be able to conduct each of the distinct forming methodologies in a single pass through one set of rollers 180, 190.

[0129] The profile 1, for example where one or more of the base 2, side portions 3, 4, ledge portions 5, 6 are work hardened, and formed in accordance with the invention, has better compression characteristics than those absent the array of projections 10a-d.

[0130] This is surprising because the profile has not been work hardened in the joining portions but rather has been embossed, which leads to thinning. It is the joining portions which are required to withstand deflecting forces. Consequently, one would expect a deterioration in the compression characteristics, as compared to a profile which had been work hardened or which had not been processed (embossed) at all.

[0131] Referring to FIGS. 7, 7A, 7B and 7C, there is shown a profile 50 according to the invention with an array of projections 60 along each joining portion JP1″, JP2″ and joins J1″ and J2″. The projections 60 extend outwardly from the exterior surface of the profile 50. Whilst not shown, one or more or each or all of the surfaces of the profile 50 (outside of the joins J″ and joining portions JP″) may be work hardened in accordance with the above description and/or knurled or otherwise treated. We prefer that the surfaces are work hardened. The profile 50 may be a C, U or other shaped section, and the characteristics of the sheet and/or projection(s) described below are equally applicable to other sectional shapes, projection shapes and so on.

[0132] The array of projections and each projection 60 has one or more of a pitch P, a width W, a form depth F and a form position FP.

[0133] The pitch P is the inter projection (formation) distance. For a sheet material with a gauge G we prefer a pitch P which can be 2 to 20 times the base gauge G and is preferably from 5 to 15 times the base gauge G of the material. Preferably the pitch P is from 6 to 14 times the base gauge G, and most preferably from 8 to 12 times the base gauge G.

[0134] The width W of each projection 60 is determined as the linear distance between the intersection of a line denoting a tangent α of the apex of the top surface 60t of the projection 60 and lines formed between the start of the root part (e.g. 193b in FIG. 6B) of the embossing region (e.g. 191b in FIG. 6B) of a roll (e.g. 190b in FIG. 6B) when engaging the sheet material to form the projection 60 and the flat portion of the sheet material immediately outboard of the projection. In some embodiments the width W of a projection may be from 0.2P to less than P, preferably from 0.25P to 0.75P and most preferably from 0.4P to 0.6P.

[0135] The form depth F is the distance between a first face 60f of the sheet material and the top surface 60t (or a tangent α of the apex of the top surface 60t where the top surface 60t is not flat, as shown) of a projection 60. In some embodiments the form depth F of is between 1.5 and 4 times the base gauge G of the material, preferably between 1.6 and 3.5 times the base gauge G and most preferably from 1.8 to 3 times the base gauge G.

[0136] The form position FP is defined as the linear distance between the end of the curved part of a projection 60 on a joining portion JP1″ (or JP2″) and the end of the curved part of the profile 50. In some embodiments the form position FP of a projection may be from 0.2G to G, preferably from 0.25G to 0.75G and most preferably from 0.4G to 0.6G.

[0137] In the region of the joining portion JP1″ (or JP2″) the projection 60 may be curved. Such a curved projection 60 may have an internal radius of curvature IR and an external radius of curvature OR. In some embodiments the internal radius of curvature IR of a projection may be from 0.2G to G, preferably from 0.25G to 0.75G and most preferably from 0.4G to 0.6G. The external radius of curvature may be IR+G.

[0138] Because of the nature of the embossment, the sheet material is stretched when forming the projections 10. The resultant thickness RT (for example as measured in the direction of the line XX-XX in FIG. 7C—a line 45° to the principal axis of the sheet material) is preferably from 0.9G to 0.55G where F is from 1.8 to 3G. Because the sheet material is clamped during the embossing process between a male and female former the thickness of the sheet in the region of the top surface 60t (i.e. as measured in a direction perpendicular to the principal axis of the sheet material) remains unaltered, or at least substantially so and there is no change in the physical properties of the sheet in that region. Thus, it is the side portions of each projection 10 which experience thinning as a consequence of the embossing operation.

[0139] The characteristics described above in relation to FIG. 7 are equally applicable to one or more of the other embodiments. In each case above (and preferably in each case of the invention), flat lands FL are provided between successive members of an array. In the region of the flat lands the sheet material remains at least substantially unaltered.

[0140] In FIG. 8 there is shown plural stud profiles 1 in a vertical orientation located between upper and lower horizontal tracks (UT and LT respectively) with lengths of plasterboard PB abutting the first side portion 3 and second side portions 4. As shown, at at least some of the stud profiles 1 an edge of a length of plasterboard PB1 is aligned with the longitudinal rib 30, which can provide a visual location guide to the installer. An edge of a further length of plasterboard PB2 is brought into abutment with the edge of the plaster board PB1, thereby to form part of a stud wall SW. Because of the increased resistance to compression provided by the projections 10a-d, the side portions 3, 4 are much less likely to flex, with respect to the base portion 2, when the plasterboard PB1 (and/or the further length PB2) is secured to the profile 1. This has the effect of reducing incidence of the phenomenon known as “board stepping”. One or both of the tracks LT, UT can be formed with projections 10 according to the invention. One or some or all of the portions of each profile outside of the joining portions (or joins, if present) may be cold rolled and work hardened, embossed, knurled, coined and so on. We prefer at least some of those portions (and preferably each) to be cold-work hardened, for example as disclosed in our above-identified patents (EP0891234 or EP2091674, preferably the latter), and as shown in relation to FIGS. 5 and 6.

[0141] In order to demonstrate the increase in compression resistance a series of tests were carried out, as follows.

Example 1

[0142] In order to test the stiffness of a single portion of the profile 1 of the invention, one of the wall portions 3 or 4 of a profile according to the invention was loaded and the deflection measured. The profile had the following characteristics, width 63 mm, wall height 32 and 34 mm. The base gauge G was 0.5 mm the projections had a pitch P of 5 mm, and each was 7 mm long, and had a width W of 2.5 mm, a form depth F of 1 mm and RT was 0.4 mm.

[0143] The test enabled the stiffness to be calculated. We call this a Single Leg Test.

Comparative Example 1

[0144] A profile of identical size and length but absent the projections 10 of the invention was tested in an identical manner.

[0145] The results are shown in Table 1.

TABLE-US-00001 TABLE 1 Single Leg Test data for Example 1 and Comparative Example 1 Deflection (mm) Deflection (mm) Stiffness at 50N at 150N (N/mm) Variation (%) Ex. 1 0.667 1.967 38.5 (1) C. Ex. 1 0.52 1.8107 38.7 —

[0146] The data in Table 1 demonstrates that the stiffness of the profile 1 of the invention is practically identical to that of a profile of the prior art. This is a surprising result because the thinning of the material brought about as a result of the embossing would lead one to expect that the stiffness would be reduced in a profile 1 of the invention.

Example 2

[0147] In order to test the stiffness of both wall portions of the profile 1 of the invention, both of the wall portions 3 or 4 of a sample identical to that described in Example 1 were loaded and the deflection measured, we call this a Double Leg Test. This enabled the stiffness to be calculated.

Comparative Example 2

[0148] A profile of identical size and length but absent the projections 10 of the invention was tested in an identical manner.

[0149] The results are shown in Table 2.

TABLE-US-00002 TABLE 2 Double Leg Test data for Example 2 and Comparative Example 2 Deflection (mm) Deflection (mm) Stiffness Variation at 50N at 100N (N/mm) (%) Ex. 2 2.255 4.83 19.4 6 C. Ex. 2 2.32 5.06 18.2 —

[0150] The data of Table 2 demonstrates that the deflection profile and stiffness of the profile 1 of the invention is substantially greater than that of a profile of the prior art. These are surprising results, not least because of the apparent identicality under the Single Leg Test and because of the change of the material brought about as a result of the embossing would suggest that the stiffness would be reduced in a profile 1 of the invention. We believe that this shows a significant improvement over the prior art.

Example 3

[0151] We conducted some comparative tests on a sample of stud 1 having ‘external’ projections 10 according to FIG. 1 (Example 3A) and a sample of stud 1′ having ‘internal’ projections 10′ according to FIG. 2 (Example 3B). Each of the studs 1, 1′ had a base wall 2, 2′ of 70 mm, a first side wall 3, 3′ of 34 mm, a second side wall 4, 4′ of 32 mm and in-turned ledges 5, 5′, 6, 6′ of 6.5 mm.

[0152] Both studs 1, 1′ had the same number and array of projections 10, 10′ (that being the array shown in FIG. 1 which is projections at each of the joining portions JP1 (of JP1′)-JP4 (or JP4′)).

[0153] The moment of inertia and sectional modulus of each of the studs 1, 1′ was determined.

Comparative Example 3

[0154] A profile of identical size and shape but absent the projections was tested in an identical manner.

[0155] The results are shown in Table 3.

TABLE-US-00003 TABLE 3 Data showing the moment of inertia (I) and sectional modulus (Z). I.sub.XX (mm.sup.4) I.sub.YY (mm.sup.4) Z.sub.XX (mm.sup.3) Z.sub.YY (mm.sup.3) Ex. 3A 60500 10700 1650 420 Ex. 3B 58200 10100 1700 450 C. Ex. 3 58200 9700 1650 410

[0156] It can clearly be seen that the moment of inertia I (indicative of the resistance to bending) is higher in both of the examples of the invention by between 4 and 10% and the sectional modulus from 2.5 to 7% (both in the y direction).

[0157] Both these results show that a profile made in accordance with the invention is stiffer than a profile made in accordance with the prior art.

[0158] To further test the performance of profiles of the invention, we conducted some further tests.

Example 4

[0159] We conducted a series of three point bend tests on plural samples of profiles made according to the invention and formed in accordance with FIG. 1 and Example 1. Pairs of profiles with a length of 2.2 m were mounted as shown in FIGS. 9A to 9C and a load was applied to the mid-point of the pairs of profiles.

Comparative Example 4

[0160] A pair of profiles of the same dimensions but absent the projections were tested in the same manner as set out in Example 4.

[0161] The results (average of 3 runs in each case) are shown in Table 4.

TABLE-US-00004 TABLE 4 Three Point Bend Test data for Example 4 and Comparative Example 4 Maximum load Maximum Force @ Force @ (N) Extension (mm) 3 mm (N) 5 mm (N) Ex. 4 1338 17 245 430 C. Ex. 4 848 12 226 383

[0162] The results clearly demonstrate that the profile of the invention performed better in terms of its ability to withstand deflecting forces than a profile of the prior art.

Example 5

[0163] We decided to further investigate single leg compression performance by mounting a series of profiles of the invention in a test rig as shown in FIG. 10. The profiles of the invention were made in accordance with those of Example 1 and FIG. 1.

Comparative Example 5

[0164] We tested a series of prior art profile having the same dimensions as those of Example 5 but absent the projections.

[0165] The results (average of four runs in each case) are shown in Table 5.

TABLE-US-00005 TABLE 5 Single Leg Test data for Example 5 and Comparative Example 5 Maximum load Maximum Force @ Force @ (N) Extension (mm) 4 mm (N) 8 mm (N) Ex. 5 303 13 156 254 C. Ex. 5 188 14 91 153

[0166] These results demonstrate that as the amount of compression increases (that is as against Example 1), the profile of the invention shows better performance over the prior art.

Example 6

[0167] To investigate the performance of the profile of the invention a series of stud walls were constructed, the walls being either 3.6 m high (Example 6A) or 4.2 m high (Example 6B). Each wall comprised a header and footer track section of 3.6 m length and between which 7 equi-spaced studs formed from profiles according to the invention were located.

[0168] For Example 6A a single layer of plasterboard was attached to each side of the so-formed frame to form a stud wall 3.6 m high and 3.6 m wide.

[0169] For Example 6B a double layer of plasterboard was attached to each side of the so-formed frame to form a stud wall 4.2 m high and 3.6 m wide.

[0170] Each wall was subjected to a positive pressure applied uniformly over the surface of the wall, the pressure being increased at 50 N/m.sup.2 increments.

Comparative Example 6

[0171] Two identical walls were constructed from prior art profiles which had the same characteristics but were absent the embossed projections of the invention.

[0172] The results are shown in Table 6 and indicated graphically in FIG. 11A (3.6 m high walls) and FIG. 11B (4.2 m high walls).

TABLE-US-00006 TABLE 6 Wall performance data for Example 6 and Comparative Example 6 Def @ 200N/mm.sup.2 Force @ L/240 Bending Stiffness @ (mm) (N/m.sup.2) L/240 (Nm.sup.2) Ex. 6A 14 205 29944 C. Ex. 6A 16 195 28515 Ex. 6B 11 266 62311 C. Ex 6B 17 202 46918

[0173] The data demonstrates that the profile of the invention performs better when constructed as a wall than profiles of the prior art.

[0174] Moreover, in a further test it was found that board stepping was significantly reduced in profiles of the invention as compared to profiles of the prior art.

[0175] It is also within the scope of the invention to provide an array of projections 10 at each vertex of non-co-linear portions of the profile 1, or any other profile. Moreover, projections 10 may be provided at a single vertex of non-co-linear portions of a profile (or the profile 1) or indeed at plural vertices.

[0176] The projections 10 on the profile 1 extend outwardly, which is preferred because, we believe, it leads to improved performance. Some or all of the projections in the same or different arrays (10a-d) may extend inwardly. Moreover, the embossing may be carried out by use of a forming roll (e.g. roll 180 or 190) which carries formations and a plain roll (e.g. the other of roll 190 or 180) the combined action of both causing formation of the projections 10a-d. The projections may be any shape. We prefer embossed projections with a shape having a principal axis which is not parallel to the principal axis of the profile because this leads to a greater improvement in performance.

[0177] We prefer profiles which have been both embossed, that is embossed to form said projections 10, and work-hardened. Tools which can perform both operations simultaneously on a sheet material are preferred. In preferred operations and tools, the embossing and embossing regions (and consequential embossments) are bound, in the transverse direction of the work-piece or sheet metal, by work hardening and work hardening regions (and consequential work hardened regions), in the running direction of the tool, the sheet material having corresponding embossments and work hardened zones.

[0178] The embossed projections may have a pitch of 3 mm or greater. In some embodiments, in a direction along an array of projections, from 30-70% of the distance is taken up by the width W of the projections. The pitch of the projections in an array on one joining portion may be different to the pitch of projections on another joining portion on the same profile.

[0179] The profile 1 may be in other shapes. It may provide grid for a suspended ceiling or other framing or sectional members. For example, the profile can be an I, Z, W or other sectional shape, for example a box section or other three dimensional shape, whether regular, irregular or otherwise convoluted. We can provide profiles from steel up to 3 mm thick.