SUPPORTING ELEMENT AND METHOD FOR MANUFACTURING THE SAME

Abstract: An elongate supporting element has a cross section with a web (9) and two side flanges (10, 11) for the supporting of building panels or the like. The web (9) has an elongate, stress-equalising zone (4) which extends wholly or partly between the two outer ends (8a, 8b) of the supporting element and by means of which the supporting element (8) is reinforced.

Description: SUPPORTING ELEMENT AND METHOD FOR MANUFACTURING THE SAME Technical Field The present invention relates to a supporting ele¬ ment for building of walls comprising building panels and the like. The invention also concerns a method for manu- facturing such a supporting element. Background Art Supporting elements of this type are described in the "Tak-vaggkatalogen" ("Ceiling Wall Catalogue") is¬ sued in 1994 by Lindab AB, which shows the mounting of so-called building studs on pp 105-107 and which shows various arrangements of vertical studs and horizontal bars cooperating therewith on pp 108-109. Further exam¬ ples of supporting elements in the field of the invention are shown on e.g. pp 113 and 119 in the above-mentioned catalogue. The term "supporting element" is used below as a conception of studs, sections and bars etc. for the building of walls, especially walls where building panels are mounted on supporting elements. Furthermore Swedish Published Application SE-B- 457,223 (corresponding to US-A-4,513,551) discloses a supporting element of U-shaped cross-section compris¬ ing a web and two side flanges for supporting building panels or the like. To facilitate the driving-in of fas¬ tening screws when mounting building panels on the sup- porting element (cf. the Lindab Catalogue p. 105), the side flanges have areas of so-called expanded metal which guide the fastening screws (cf. Fig. 1 in SE-B-457, 223 ) . Such supporting elements as described above are manufactured from a flat sheet-metal blank which, in a special forming process, is formed to U-shaped cross-sec¬ tion. In this forming, undesired internal stress often arises in the supporting element, which may result in the entire supporting element becoming twisted, which renders the mounting operation difficult. In supporting elements of the type shown in SE-B-457, 223, the expanded metal in the flanges may cause special stress which, if the worst comes to the worst, causes the free longitudinal edges of the flanges to_ become twisted or wave-shaped. This wave shape may arise even when the two areas of expanded metal are formed on the flat sheet-metal blank, whose longitu¬ dinal edges in unfavourable cases obtain a wave shape of such great amplitude (about 40 mm) that the handling of the strip-shaped sheet-metal blank as well as the forming into the desired supporting element are rendered diffi¬ cult. There is thus a need of a new supporting element which tends to a less extent to be twisted and which does not have the above-mentioned undesired wave shape. A further general desire, which is well known to the expert, is that the supporting element should have good rigidity and withstand the linear loads perpendicular to the flanges, which arise during mounting and also when subjecting the finished wall to loads. Various measures have been suggested for the reinforcing of supporting elements, and examples are shown on p. 113 in the Lindab catalogue mentioned by way of introduction, in which the web of the supporting stud has been provided with two parallel longitudinal reinforcements in the form of grooves. However, the market now requires still more rigid supporting elements, which is the starting point of this invention. There is a need of a new type of supporting element, which has improved strength and rigidity and whose flanges in particular are reinforced such that they yield towards each other to a smaller extent when subjected to loads, for instance when mounting building panels thereon. As a further example of prior art, mention can be made of the supporting element according to US-A- 4,619,098, which for the purpose of reducing the heat and cold conductivity is formed with slits. The above- described inconvenience, i.e. undesired internal stress and insufficient rigidity, however, is not discussed in this reference. Summary of the Invention The object of the present invention is to suggest a solution to the above-described problems and consequently provide an improved supporting element. This and other objects, that will appear from the following specification, are now achieved by means of a supporting element having the features as defined in appended claim 1 and in preferred embodiments in appended subclaims 2-8. The objects are also achieved by a manu¬ facturing method according to appended claim 9 and claims 10-12 depended therefrom. Providing the inventive supporting element with a stress-equalising zone having rows of deformations in the web results in better rigidity and capacity of with¬ standing loads compared with prior-art supporting ele- ments of a similar kind. Particularly good results have been achieved by an embodiment where the stress-equalis¬ ing zone is given the form of two elongate portions, which are narrow in relation to the width of the web and which are parallel with the side flanges and each consist of a number of close cuts arranged in rows and extending wholly or partly through the material of the web, said narrow portions defining between themselves unmachined material of the web without cuts. A comparative experi¬ ment with such a supporting element will be briefly dis- cussed below. A 2400-mm-long supporting element of thin metal sheet according to the above-mentioned embodiment, where the flanges of the supporting element have areas of ex¬ panded metal, was supported at its ends and subjected to a linear load of 500 N/m. A corresponding prior-art sup¬ porting element, essentially according to Fig. 2 in SE-B- 457,223, thus having expanded-metal flanges but a com- pletely unmachined ' web, was subjected to load in the same fashion. The deflection in the centre of the supporting element according to the invention was only half as great as the deflection of the prior-art supporting element (about 5 mm compared with about 10 mm). According to the invention, a straight supporting element is obtained, which has good rigidity and no such wave shape as in the prior-art supporting element. The previous undesired internal stress of the supporting ele- ment is eliminated or changed thanks to the stress-equal¬ ising zone in the web of the supporting element. Brief Description of the Drawing The invention and its many advantages will be de¬ scribed in more detail below with reference to the accom- panying schematic drawing, which shows preferred embodi¬ ments. Fig. 1 is a perspective view of a flat sheet-metal blank. Fig. 2 is a perspective view of a supporting element according to the invention manufactured from the sheet- metal blank illustrated in Fig. 1. Fig. 3 shows on a larger scale a portion of the web of the supporting element. Fig. 4 is a view, similar to Fig. 3, of an alterna- tive embodiment of the web of the supporting element. Description of Preferred Embodiments In Fig. 1, a blank of thin metal sheet is generally designated 1, which in a manner known per se comprises two expanded-metal areas 2, 3 which are spaced from the two longitudinal edges of the sheet-metal blank 1. Between the expanded-metal areas 2, 3, the sheet-metal blank 1 has a stress-equalising or stress-changing zone 4 having rows of deformations, which in this embodiment comprise two elongate portions 5, 6, each consisting of a large number of close cuts arranged in rows and extending wholly or partly through the sheet-metal blank 1, as will be described in more detail below. The two portions 5, 6 define between themselves an area 7 of unmachined mate¬ rial without cuts. In a manner known per se, the shee -metal blank 1 shown in Fig. 1 is formed into a supporting element ac- cording to the invention, which is generally designated 8 and is shown in Fig. 2. The elongate supporting element 8 is given a U-shaped cross-section comprising a web 9 and two side flanges 10, 11 for the supporting of building panels or the like (not shown). The expanded-metal areas 2, 3 of the side flanges 10, 11 facilitate the driving-in of fixing elements, such as fastening screws or the like, for fixing the building panels. In some cases the build¬ ing panels can also be attached by gluing (not shown). It should be noted in the context that the invention is applicable also to supporting elements without such expanded-metal areas in the flanges. The stress-equalising zone 4 is preferably symme¬ trically arranged in respect of a centre plane M extend¬ ing through the supporting element 8 perpendicular to the web 9. Fig. 2 clearly shows how the stress-equalising zone 4 is placed on the web 9. According to a preferred embo¬ diment, the stress-equalising zone 4 comprises two elon¬ gate portion 5, 6, which are narrow in relation to the width of the web 9 and which are parallel with the side flanges 10, 11 and each consist of a large number of close cuts 12 arranged in rows and extending wholly or partly through the material of the web 9 (see Fig. 3). As mentioned above, the narrow portions 5, 6 define an area 7 of unmachined material of the web 9 without cuts. It should be emphasised that the cuts 12 shown in Fig. 3 can be of a different design and consist of other deformations or distortions of the material, such as embossed portions, slits etc, or combinations thereof. An alternative embodiment is shown in Fig. 4, where the cuts consist of T-shaped slits 13 arranged in rows and being, to some extent, relatively offset. It will be appreciated that several other types of cuts or distortions are possible; the important thing is that the web 9 of the supporting element 8 is provided with a stress-equalising zone having rows of deformations which result in improved rigidity and which reduce the risk of twisting of the supporting element and the occurrence of wave shape thereof. It should be particularly mentioned that the narrow portions 5, 6 with cuts must not necessarily extend all the way from one outer end 8a of the supporting element 8 to the other end 8b. In a variant (not shown) these portions 5, 6 can extend merely along part of the length of the web 9, or intermittently. According to an embodiment of the invention, which is not shown in more detail, the stress-equalising zone 4 comprises several narrow portions 5, 6 of the above-men¬ tioned type, arranged in pairs, preferably equidistantly spaced from said centre plane M. The number of narrow portions with cuts is not decisive of the invention as long as a suitable stress-equalising zone is provided in the web. In a method of manufacturing, according to an embodiment of the invention, from a flat sheet-metal blank 1 a supporting element 8 according to Fig. 2, the flat sheet-metal blank 1 is provided with its stress- equalising zone 4 in the form of a number of elongate portions 5, 6 which are narrow in relation to the width of the web 9 and which are arranged in parallel with and spaced from each other and which are formed by cutting a large number of close cuts 12 or 13 arranged in rows and extending wholly or partly through the material of the web 9. In this method, the side flanges 10, 11 of the supporting element 8 can preferably be formed with expanded-metal areas 2, 3. Finally, one more advantage of the inventive sup- porting element should be mentioned. The stress-equalis¬ ing zone in the web has, in practical experiments, been found to have a favourable effect on the sound-absorbing capacity of the supporting element. This side-effect is so advantageous that the supporting element provided according to the invention can be said to constitute a combination of a supporting stud and a stud which in technical language is called sound-absorbing stud. The inventive concept is in no way restricted to the embodiments and variants described above, but a plurality of modifications are conceivable within the scope of the inventive idea as expressed in the appended claims. It should be particularly emphasised that the invention is applicable to several types of supporting elements, as discussed by way of introduction. The cross-section of the supporting element is not decisive of the invention, but may be U-, C- or Z-shaped, etc. Moreover, the stress- equalising zone in the web of the supporting element can within the scope of the invention be provided in ways other than described above.

Claims: CLAIMS 1. An elongate supporting element having a cross- section which comprises a web ( 9 ) and two side flanges (10, 11) for supporting building panels or the like, c h a r a c t e r i s e d in that the web ( 9 ) has an elon¬ gate stress-equalising zone (4) which extends wholly or partly between the two outer ends (8a, 8b) of the sup- porting element ( 8 ) and which comprises rows of deforma¬ tions (12; 13) extending wholly or partly through the material, such as cuts, slits, embossed portions and the like. 2. A supporting element as claimed in claim 1, wherein the rows of deformations (12; 13) are arranged in at least two elongate parallel portions (5, 6) which are narrow compared with the width of the web (9 ) and which are parallel with the side flanges (10, 11). 3. A supporting element as claimed in claim 2, wherein the rows of deformations each comprise a large number of close cuts (12; 13) in rows. 4. A supporting element as claimed in claim 2 or 3, wherein the elongate narrow portions (5, 6) between themselves define unmachined material ( 7 ) of the web ( 9 ) without cuts. 5. A supporting element as claimed in claim 1, which is U-shaped in cross-section and in which the stress- equalising zone (4) is symmetrically arranged in respect of a centre plane (M) extending through the supporting element (8) perpendicular to the web (9). 6. A supporting element as claimed in claims 2 and 5, wherein the stress-equalising zone (4) comprises a plurality of narrow portions (5, 6) of the above-mention¬ ed type, arranged in pairs and equidistantly spaced from said centre plane (M). 7. A supporting element as claimed in any one of the preceding claims, wherein the side flanges (10, 11) are made largely of expanded metal. 8. A supporting element as claimed in any one of the preceding claims, which is made of thin metal sheet. 9. A method of manufacturing from a flat sheet-metal blank an elongate supporting element (8) having a cross- section which comprises a web (9) and two side flanges (10, 11) for supporting building panels or the like, c h a r a c t e r i s e d in that that area of the flat sheet-metal blank (1) which is to form said web (9) is formed with a stress-equalising zone (4) in the form of rows of deformations (12; 13) extending wholly or partly through the material, such as cuts, slits, embossed por- ions and the like. 10. A method as claimed in claim 9, wherein the rows of deformations (12; 13) are formed as elongate parallel portions (5, 6) which are narrow in relation to the width of the web ( 9 ) and are arranged in parallel with the side flanges (10, 11) and which are formed by cutting a large number of close cuts (12; 13) arranged in rows and ex¬ tending wholly or partly through the material of the web (9). 11. A method as claimed in claim 9 or 10, wherein the sheet-metal blank ( 1 ) is formed to U-shaped cross- section. 12. A method as claimed in claim 9, 10 or 11, where¬ in the side flanges (10, 11) are formed with expanded- metal areas.

Inventors: EKERHOLM BENGT, LARSSON HANS, SVENSSON INGMAR, EKERHOLM, BENGT, LARSSON, HANS, SVENSSON, INGMAR
Applicants: EKERHOLM BENGT, LARSSON HANS, LINDAB AB, SVENSSON INGMAR, EKERHOLM, BENGT, LARSSON, HANS, SVENSSON, INGMAR
Application year: 1997
Main classification: E04C3
IPC codes: E04C3