A SHEET METAL PROFILE AND A METHOD OF MANUFACTURING THE PROFILE, WHEREBY AN INITIAL LOCAL DEFORMATION IS LARGER THAN THE FINAL

Abstract: The present invention relates to a sheet metal profile, preferably a so-called high profile of high bearing capacity, comprising an upper flange part (1), two webs (2, 3) which extend down from the upper flange part and the bottom ends of which merge with a web-connecting bottom flange part (4). The sheet metal profile is stiffened by providing the webs (2, 3) with stiffening, local impressions (5) in the transverse direction of the metal sheet.

Description: A sheet metal profile and a method of manufacturing the profile, whereby an initial local deformation is larger than the final . The present invention relates to a sheet metal pro- file, preferably a so-called high profile of high bearing capacity and including an upper flange part, two webs which extend downwardly from said flange part and the bottom ends of which merge with a bottom flange part which connects said webs. The invention also relates to a method of manufacturing the sheet metal profile. With the intention of stiffening sheet metal profiles of the aforesaid kind in order to increase their bearing capacity, it has earlier been usual to provide the profile with a stiffening profiled section which extends in the longitudinal direction of the profile. This stiffening profile section can be provided at the same time as the metal sheet is given its main pro- filed shape. Despite the aforesaid formation of sheet metal pro¬ files with the intention of stiffening the profiles, it has nevertheless been found difficult to obtain thin sheet metal profiles which are able to support more than their own weight when the metal sheet has a span in excess of about 5-6 meters. Accordingly, the object of the present invention is to provide a novel sheet metal profile of high bearing capacity which is able to manage spans which exceeds the aforesaid value. A further object of the invention is to provide a method for the manufacture of the novel sheet metal profile. These objects of the invention are achieved with a sheet metal profile and a method having the character¬ istic features set forth in the following claims. The invention will now be described in more detail with reference to a non-limiting, exemplifying embodi¬ ment thereof and also with reference to the accompany¬ ing drawings, in which Figure 1 illustrates part of the web of a sheet metal profile containing impres¬ sions in accordance with the invention; Figure la is a side view of the web and shows the impressions accord¬ ing to the invention; Figure lb is a sectional view taken on the line A-A in Figure la and illustrates the web subsequent to the metal sheet having passed through a first pair of rolls; Figure lc is a view corresponding to Figure lb but showing the metal sheet subsequent to having passed through a second or a last pair of rolls; Figure 2 is a schematic side view of two roll pairs which form the stiffening impressions in the sheet metal profile in accordance with the invention; and Figure 3 is a sectioned view showing a widened abutment surface of the roll pairs at the precise moment of pressing the stiffening impressions in said metal plate, said section being taken general¬ ly on the line B-B in Figure la, and Figure 3a is a section view showing the pressing sequence in the first roll pair, and Figure 3b is a corresponding view showing pressing of the metal sheet in the second roll pair; and Figure 4 is an end view of a part of the finished, profiled metal sheet according to the inven¬ tion, said sheet also being provided with a stiff¬ ening, additional profile. The invention thus relates to part of a sheet metal profile, particularly a so-called high profile whose configuration is best seen in Figure 4. The profile includes an upper flange part 1 and two webs 2 and 3 which extend generally vertically downwards from the upper flange part. The bottom ends of the two webs merge with a respective bottom flange part 4, which connects the two webs 2 and 3 with respective webs 3 and 2 on the next raised profile. In order to stiffen the sheet metal profile and to enhance its bearing capacity, the webs 2 and 3 are provided with local impressions 5, which are prefera¬ bly pressed into the plate alternately from different directions, or outwards and inwards as seen in Figure 1 or Figure 4. This is particularly shown in Figures lb and lc. The impressions 5 are essentially of paral¬ lelogram shape, possibly rectangular, with a greater extension in the height direction of the webs 2, 3, than in the longitudinal direction of the profile. As will be seen from Figure la and Figure 4, the impres¬ sions 5 extend over the major part of the height of the webs 2, 3. When the shape of the impressions 5 is not rectangular, the impressions are formed so as to alternately slope towards one another, as illustrated in Figure la. The aforesaid impressions 5 are conveniently formed in the flat metal sheet prior to corrugating the sheet in the manner shown. When corrugating the flat metal sheet, the profile may also be provided with further stiffening folds or corrugations 6 which extend in the longitudinal direction of the metal sheet profile and are suitably placed in both the upper flange part 1 and the bottom flange part 4. The stiffening folds 6 are shown in Figure 4. In order to further stiffen the sheet metal profile, when using the same a stiffening, essentially U-shaped strengthening profile 7 can be inserted in the corru¬ gations of the sheet metal profile, this strengthening profile 7 being inserted beneath the upper flange parts 1 and between the webs 2 and 3, as shown in Figure 4. The free ends of the legs 8 and 9 of the U- shaped strengthening profile 7 support against the underside of the upper flange part and the horizontal part.10 of the U-shaped strengthening profile is disposed so as to lie essentially in the plane of the bottom flange transverse beam, similar to the bottom flange part of the profile. The legs 8 and 9 of the U-shaped strengthening profile are suitably also provided with impressions 11 that correspond to the impressions 5 in the webs 2 and 3 of the sheet metal profile. This will provide a highly rigid strengthening profile 7, which further increases the bearing capacity of the inven¬ tive sheet metal profile. As beforementioned, the invention also relates to a method of manufacturing the inventive sheet metal pro¬ file. The method is best seen from Figures 2 and 3. As will be seen from, a thin metal sheet 12 is fed be- tween a first pair of mutually coacting rolls 13a, 13b and then through a second pair of mutually coacting rolls 14a, 14b. The two roll pairs 13 and 14 are each provided with coacting raised parts or ridges 15 and recesses 16, although the ridges and the recesses on the first roll pair 13 have a greater height and a greater depth than the ridges and the recesses on the second roll pair, so that as the metal sheet passes through the second roll pair 14 part of the impression 5 in the metal sheet will be pressed back into the plate, as will be seen when comparing Figures lb and lc and in particular from the enlarged view shown in Figures 3a and 3b. The depth of the impression formed by the first roll pair 13 may, for instance, be 2.5 mm while the impression depth formed by the second roll pair is only 1.5 mm, thus the metal sheet has been pressed back through a distance of 1 mm. In this way, there is obtained a stiffer impression than would be the case if the impression was formed solely in one step and to a determined depth. This type of i pres- sion is formed on both the metal sheet which is to form the sheet metal profile and also on the metal sheet used to produce the aforesaid optional strength¬ ening profile 7. Subsequent to a thin metal sheet having been provided with the impressions 5 in the roll pairs 13 and 14, the thin metal sheet is passed to a profiling mill, where the metal sheet is profiled, for instance to the configuration illustrated in Figure 4. The optional strengthening profile 7 is subjected to a correspond¬ ing method. It will be understood that the inventive metal sheet profile need not have the profiled configuration illustrated in Figure 4, but may have any profiled configuration suitable for the purpose intended, since the essential feature of the present invention is to stiffen the metal sheet with the aid of impressions in the web of the sheet metal profile.

Claims: Claims 1. A sheet metal profile, preferably a so-called high profile having a high bearing capacity and comprising an upper flange part (1) , two webs (2, 3) which extend down from the flange part and the bottom ends of which merge with a bottom flange part (4) which connects the webs (2, 3), c h a r a c t e r i z e d in that the webs (2, 3) are provided with local stiffening impres- sions (5) in the transverse direction of the metal sheet. 2. A profile according to Claim 1, c h a r a c ¬ t e r i z e d in that the impressions (5) in the webs are formed alternately outwards and inwards. 3. A profile according to Claim l or 2, c h a r a c ¬ t e r i z e d in that the impressions (5) have essen¬ tially the shape of a parallelogram, with a greater extension in the height direction of the webs (2, 3) than in the longitudinal direction of the profile. 4. A profile according to Claim 3, c h a r a c ¬ t e r i z e d in that the impressions (5) slope alternately in relation to the transverse direction of the profile. 5. A profile according to any one of the preceding claims, c h a r a c t e r i z e d in that the flange parts (1, 4) of the metal sheet are provided with stiffening grooves (6) in the longitudinal direction of the profile. 6. A profile according to any one of the preceding claims, c h a r a c t e r i z e d in that generally U-shaped strengthening profiles (7) are placed beneath the upper flange parts (1) , with the legs (8, 9) of said strengthening profile supporting against the upper flange parts (1) , and with the horizontal part (10) of respective U-shaped strengthening profiles lying essentially in line with the bottom flange part (4) of said profile. 7. A profile according to Claim 6, c h a r a c ¬ t e r i z e d in that the legs (8, 9) of the U-shaped strengthening profiles are provided with local impres¬ sions (11). 8. A method for manufacturing a sheet metal profile according to any one of Claims 1-7, c h a r a c ¬ t e r i z e d by feeding a thin metal sheet (12) be¬ tween at least one pair of mutually coacting rolls (13) provided with raised parts (15) and recesses (16) such as to form local impressions in the metal sheet (12) and then feeding the metal sheet through a pro¬ filing mill to profile the sheet. 9. A method according to Claim 8, c h a r a c - t e r i z e d by forming the impressions alternately upwards and downwards in the metal sheet (12). 10. A method according to Claim 8 or 9, c h a r a c ¬ t e r i z e d by feeding the metal sheet (12) through two sequential roll pairs (13, 14) and forming impres¬ sions in the first roll pair (13a, 13b) to a predeter¬ mined depth and pressing the impressions back to a smaller depth in the second roll pair (14a, 14b).

Inventors: NAESLUND GUSTAV, NAESLUND, GUSTAV
Applicants: KORSTRAESK MEK AB, KORSTRAESK MEKANISKA AB
Application year: 1993
Main classification: E04C2
IPC codes: B21D5, B21D13, E04C2, E04D3