Sheet profiling machine

Abstract

 A machine for profiling metal sheets for use primarily in roofing and also in cladding surfaces. The set up of the machine and the method of operating it is specified so as to provide defined conditions in a region (A) of the sheet metal which is entering the machine. The region (A) is located between a guide set (G.1,G.2) which holds the sheet flat in a transverse direction to the longitudinal (feed) direction into the machine and the first (C1.A) of a number of roll sets (C1.A,C1.B,C1.1,C1.2,C1.3) which first roll set (C1.A) commences forming a longitudinally extending ridge (11) in the sheet. The defined conditions are that the sheet is concave on its upper surface both in longitudinal and transverse directions save for a bulge (10), described as a "lordosis" which is convex on the said upper surface. A region of contraflexure of the sheet in advance of the said region is advantageous.

Description

[0001] This invention lies in the field of profiling roof sheets, generally metal roof sheets and profiling sheets used for cladding surfaces other than roofing, for example, on vertical surfaces and underneath surfaces such as ceilings.

[0002] The invention has particular application, by way of example, to the profiling of CraftLock® (TRADE MARK) roofing sheets. This is a profile as is described in South African patent 83/2689. This profile is important because it provides a side joint between roof sheets which does not leak even at very low slopes of the roof, the side joints being the joints between sheets which run down the slope. The profile also is joined to adjacent sheets and held to the rafters without any perforation of the sheet.

[0003] S.A. patent number 83/0940 discusses development of a lightweight and short length rolling machine for profiling sheet material, in particular sheet metal for roofing. Because of the lightness and shortness of the machine it can be transported economically to a building site for rolling profiled sheets on the building site from a coil of flat sheet material. This allows rolling each sheet to a sufficient length to cover the roof of a particular building site in a single unbroken length of profiled sheet. This is important to achieve a waterproof roofing produced from profiled sheet metal when the pitch angle is very low, for example, down to 1°.

[0004] It is in many cases only possible to achieve full length unbroken roof sheets by rolling on site because they are too long to be transportable from a factory to the building site.

[0005] The features described in these two patents thus held out the promise of leak free roofing at very low slopes, by the combination of the three features of unbroken lengths over the whole roof, unperforated roof sheets and leak free side joints.

[0006] The equipment described in S.A. patent 83/0940 and the method of use of this equipment described in the patent thus offer the potential for significant economic advantages in the provision of profiled sheet metal roofing or cladding on a building.

[0007] In the supplementary disclosure which is on file with patent 83/0940 dated 26 September 1983 an aspect of the equipment was described which is adapted to flex or undulate the flat sheet material in a longitudinal direction just ahead of the first roll pair at which the profiling of that sheet material into a transverse profile would commence. In particular an "S-bend" was stated to be likely to be most suitable. This feature was described to have been found to inhibit a problem associated with rolling a transverse profile in sheet metal, namely the formation of wrinkles in the sheet metal. By this solution a relatively short rolling machine could still be used with a relatively low power motor to drive it.

[0008] The problem of roll forming a transversely profiled sheet metal using a machine with these constraints as have been described in patent 83/0940 have proved to be greater than was then anticipated.

[0009] The solution proposed in the said supplementary disclosure did not succeed, the problem of wrinkling was not reliably solved and and a tendency to veer to one side or another of the rolls was also not solved.

[0010] The equipment and the method of rolling have as a result been the subject of ongoing research and development. This research and development has led to the realisation that the solution of the problems of wrinkling and veering lies in defining the set up of a machine as referred to, being an exceptionally light and short machine as compared to the norm of the art. The lightness and shortness, as mentioned, are unavoidable in order to achieve the advantage of a transportable rolling machine which can be towed to a building site and this allows rolling on site the long sheets to cover the whole roof, which can not be transported because of their length.

[0011] This research and development has led to the solution of this problem, in accordance with the present invention, in which new characteristics of the set up of the equipment and of a method of roll forming profiled sheet material is defined.

[0012] In accordance with the present invention there is provided a configuration of guides and rolls in a set up of a machine for roll forming profiled sheet material from flat sheet material, which machine includes:
one or more sets of guides through which the sheet first passes longitudinally during forming, at which sets of guides the sheet is in its initial flat condition in a transverse direction and a first set of transverse profile forming rolls which commence formation of a central longitudinally extending ridge on a first surface of the sheet, characterized in that the guides and rolls are so configured in a set up of the machine as to cause the sheet to flex in a curve which is concave on the said first surface of the sheet, in the longitudinal direction, in a space between the said guides and the said rolls, the said profile forming rolls set is adapted to cause the sheet, in the said space which has the longitudinally extending concave curve, a general concavity on the same said first surface in a transverse direction, modified by lordosis longitudinally in line with the ridge.

[0013] ["Lordosis" is defined in the Oxford and Webster dictionaries with reference to the spine as an anterior or forward curvature producing a convexity in the front. In the present context the sheet has a concavity both longitudinally and transversely over most of its surface, but modified by a convexity over a part but not all of this surface. Accordingly the word was found useful to define this characteristic of the set up and the method. Reference is made to the drawings (with reference to which further description is given below) for a visual representation of the shape.]

[0014] The lordosis arises as a result of the constraints of the set up imposed on it, as defined. Accordingly the invention can also be defined as a method of rolling sheet material which has a first surface, characterized in that the sheet is caused to flex in a curve which is concave on the said first surface of the sheet, in the longitudinal direction and in the said space which has the longitudinally extending concave curve, a general concavity on the same said first surface in a transverse direction, modified by lordosis longitudinally in line with the ridge.

[0015] This space between the roll set at which the sheet is still flat and the roll set which first commences to form the transverse profile in the form of a longitudinally extending ridge thus has a first surface which is concave both in the longitudinal as well as the transverse direction. This two-dimensonal concavity is modified by lordosis in the central region which presents as a contraflexure when seen in a transverse direction, longitudinally in line with the ridge. The degree of contraflexure may be very slight, hardly discernible to the eye until very closely observed, but these shapes generated in the sheet in the said space have a critical effect on achieving the objectives of roll forming the profiled sheet with relatively low power in a relatively short machine.

[0016] The generally transverse concavity and longitudinal concavity of the sheet imply that in the central region of the sheet the material is stretched as compared with the edges of the sheet, the sheet has a shape somewhat like a square sail of an old type sailing ship filled with the wind, modified by the slight lordosis in the central region.

[0017] The result achieved by this is a stability of the sheet, an absence of wrinkles and a relatively low power requirement to roll form the profile in a relatively short machine.

[0018] The invention will be more fully described by way of example with reference to the accompanying drawings in which :

Figure 1 is a side elevation of sets of rolls schematically through which a sheet first passes during roll forming,

Figure 2 is a plan view thereof,

Figure 3 is a front elevation of the first profile forming roll set,

Figure 4 is a transverse cross sectional elevation on the sheet material just after passing through the roll set shown in figure 3,

Figure 5 is a plan view on the sheet material in the area of sheet material shown in figure 1,

Figure 6 is a transverse sectional elevation of the fully profiled sheet material produced at the end of the machine,

Figure 7 is a side elevation as a general view of the machine, and

Figure 8 is a side view of a truck and trailer carrying a machine as shown in figure 7, with a coil carried on the truck and fed to the machine.

[0019] The description of the preferred embodiment of the invention can be commenced by a reference to figure 7 in which the machine for roll forming profile sheet material from flat sheet material is shown in general view. This is an example of the exceptionally short and light machine which is easily transportable to a building site. The description of the machine can conveniently be divided into a description of sections indicated in figure 7 as sections A, B, C and D.

[0020] Section A is the part of the machine of central importance to the present invention, being the part which commences formation of the central ridge in the transverse profile which is rolled into the flat sheet by the machine and creates stability in the sheet in the region A where it enters the machine. The conditions in the sheet metal established in the region A make possible the successful rolling in the relatively light and short machine with closely spaced roll clusters as will be described further below.

[0021] The region A is shown in figure 1 together with a sheet metal in the process of being formed in this region of the machine and also extending into the region B.

[0022] Referring to figure 1 the important roll cluster Cl.A is seen, followed by the roll cluster C1.B and the roll clusters in the region B, Cl, 1, Cl.2 and CI.3. In the region A, preceding the roll clusters A and B are the flat sheet guides G.1 and G.2. The so-called guides G.1 and G.2 are in fact parallel cylindrical rolls which do not have any profile forming action on the sheet but retain the sheet entirely flat in a transverse direction. The rolls 1 and 2 thus form the guide G.1, and the rolls 3 and 4 the Guide G.2, both sets of rolls being mounted on a frame 5 at a selected elevation relative to the roll clusters of the remainder of the machine. The flat sheet metal is fed into these first guides in the direction indicated by the arrow head 6 from a coil of the sheet metal which is located on a truck to which the rolling machine is hitched.

[0023] This can be understood better by reference to the view of figure 8 which corresponds to figure 1 in patent 83/0940, in which a rolling machine 42 is shown hitched to a towing vehicle 41 on which the flat sheet material is provided in a coil 44 and led off the coil at 44,1 towards the rolling machine. This is as indicated by the arrow head 6 in figure 1 of the present patent.

[0024] The sheet metal then continues in the space 7 between the guides or rolls 3,4 at the guide G.2 at which the sheet material is in a flat condition in a transverse direction and the first set of transverse profile forming rolls at the rolls cluster Cl.A. The upper surface of the sheet is thus concave in a longitudinal direction as shown by the line 8 in figure 1.

[0025] In the position E (fig. 1) near the guide rolls 3,4 the sheet undergoes a contraflexure from a curve which is convex in the longitudinal direction, in the region F, on the upper surface to the said concave curvature in the region A on the upper surface, in a longitudinal direction.

[0026] The line 8 is at the central portion of the sheet, the edges of the sheet are shown by the line 9 in figure 1, a feature that can be understood by reference to the view of figure 4 which shows that in this region the sheet is concave also in a transverse direction and in the view of figure 4 the edges of the sheet are indicated again by the numeral 9 and the central region of the sheet by the numeral 8. The line 9 is also concave on the upper surface of the sheet. This concavity of the upper surface both in a longitudinal and in a transverse direction is modified by a degree of lordosis or contraflexure indicated by the numeral 10 in the central region of the sheet (figure 4) which is longitudinally in a line with the ridge 11 (figure 6) which is to be formed.

[0027] The ridge which is to be formed is indicated by the numeral 11 in the views of figures 1 and 6 and it is developed to its full depth in the region B of the sheet shown also in figure 1. The outer edges 9 of the sheet thus move to a position which is below the upper edge of the ridge 11 as can be seen in the region B of figure 1.

[0028] The roll sets 1-2 and 3-4 are at an angle to the horizontal alpha shown in figure 1 which thus establishes the corresponding angle alpha of the flat sheet material where it passes between the roll sets G.1 and G.2. Optionally, in the context of this invention, this angle alpha is a smaller angle than the angle beta of the sheet metal in the space 7 between the roll set G.7 and Cl.A and this thus establishes a "S-bend" or contraflexure seen in the view of figure 1 which has been referred to in the patent 83/0940. This is not essential to the present invention, the present invention being related to the concave curvature of the sheet in the region 1 both in the longitudinal and transverse direction that has been described with the degree of lordosis which has been described.

[0029] However, it has unexpectedly been found, in the context of the present invention, that it is advantageous to combine this longitudinal contraflexure with the features of the present invention.

[0030] The roll cluster Cl.A is formed by the rolls 12 and 13 and these are shown in front elevation in the view of figure 3. The roll 13 is seen also in the view of figure 2 which is a cross sectional view along the cross sectional line II - II shown in figure 1. As seen in figures 2 and 3 the roll 13 has a central portion 13,1 which is prominent having a larger diameter, and side portions 13,2 which taper downwardly away from the prominent central portion 13,1, being conical of reducing diameter in the directions away from the central portion. Portion 13,1 is proud of the contiguous part of the portion 13,2, forming a slight step (e.g. about 1 mm). This prominent central portion is largely responsible for the "lordosis" formed in the sheet material in the region 7. Correspondingly the roll 12 has side portions 12,1 which taper outwardly, i.e. are conical with diameters increasing away from a central portion 12,2, somewhat following the downwardly tapering portions 13,2 of the roll 13 and then tapering towards a smaller diameter in the extreme outer portions 12,3. The central portion 12,2 co-acts with the central portion 13,1 of the roll 13. The outer portions 12,3 allow the forming of the transverse general concavity of the sheet with central lordosis at 10, as seen in fig. 4. The portion 12,2 is freely rotatably mounted on the remaining parts of the roll 12 so that it can freely follow the speed of rotation of the larger diameter portion 13.1 of the roll 13. The rolls 12 and 13, as with all of the rolls in the roll clusters 1 - 16 are driven by means of longitudinal shafts (not shown) running along the length of machine and having bevel gears to transmit the drive to the rolls in the roll clusters. The rolls 14 and 15 forming the roll cluster Cl.B are interposed between the roll clusters Cl.A and Cl.1 to stabilise the formation of the ridge 11.

[0031] The fact that the sheet is stretched (plastic elongation) in the region A, in particular the part of the region A between the roll cluster G.2 and the roll cluster Cl.1 in the middle of the sheet but not at the edges can be seen from a comparison of the lengths of the curve 8 and for the centre of the sheet and 9 for the edges of the sheet as shown in figure 1. The curve 8 is longer than the curve 9 showing that the sheet is longitudinally stretched. This means that the sheet is under longitudinal tensile deformation in this region, the edges are under elastic tension but not plastic deformation and the formation of the ridge 11 is commenced by the lordosis at the region 10 (figure 4). This stabilises the condition of the sheet material in a manner which is favourable to its further passage through the rolling machine. The roll clusters in the region B, Cl.1, Cl.2 and Cl.3 further develop the ridge 11 with the result that the edges of the sheet are drawn inwards towards each other making the overall width of the sheet narrower. This can be seen in the illustration of figure 5 which is a plan view of the sheet in the region A and the region B. Thus the contraction of the edges 9 of the sheet can be seen, the formation of the ridge 11 with the line 16 indicating the limit of the sidewalls of the ridge 11. The lordosis of the sheet is created in the area limited by the line 17 in the view of figure 5. The cross sectional shape of the sheet is indicated by the line 18 in the are just ahead of the roll set Cl.A showing that the sheet is generally concave but with a degree of lordosis 10. The cross section of the sheet in the area of the roll cluster Cl.1 is shown by the line 19 which shows the beginning of the formation of the ridge 11 and the cross section of the sheet in the region of the roll cluster Cl.3 as shown by the line 20 showing the essentially final form of the central ridge 11 and remainder of the sides of the sheet.

[0032] The final profile to be obtained in this particular example is shown in figure 6 where the central ridge 11 will be seen. This is in fact the CraftLock® (TRADEMARK) profile which is described in the South African patent 83/2689. The edge regions 21 and 22 provide for interlocking sheets with each other in a water tight manner as is described in that patent.

[0033] The region C of the machine contains the roll sets Cl.4 to Cl.16 (not shown) which accomplish the formation of the edge profiles and the minor stiffening profiles 23 and 24.

[0034] The region D of the machine contains a disc cutter mounted on transverse rails which can be used to cut off the profiled sheet which exits from the machine at the position 26 when a sufficient length has been rolled out and this is then to be cut off.

[0035] It will be immediately apparent to any person skilled in the art that although certain embodiments only of the invention have been set out herein, other modifications and/or variations of the invention are possible. Such modifications and/or variations are to be considered as falling within the spirit and scope of the present invention.

Claims

1. A machine for roll forming profiled sheet material from flat sheet material, which machine includes one or more sets of guides (G.1,G.2) through which the sheet first passes longitudinally during forming, at which sets of guides (G.1,G.2) the sheet is in its initial flat condition in a transverse direction and a first set of transverse profile forming rolls (Cl.A) which commence formation of a central longitudinally extending ridge (11) on a first surface of the sheet, characterized in that the guides (G.1,G.2) and rolls (Cl.A) are so configured in a set up of the machine as to cause the sheet to flex in a curve which is concave on the said first surface of the sheet, in the longitudinal direction, in a space (7) between the said guides (G.1,G.2) and the said rolls (C1.A), the said profile forming rolls set (C1.A) is adapted to cause the sheet, in the said space (7) which has the longitudinally extending concave curve, a general concavity on the same said first surface in a transverse direction, modified by lordosis (10) longitudinally in line with the ridge (11).

2. A machine for roll forming profiled sheet material from flat sheet material as claimed in claim 1, characterized in that in a space (E) near the guides set or sets (G.1,G.2) the sheet undergoes a contraflexure from the said concave curvature in a longitudinal direction to a curve which is convex in the longitudinal direction, on the said first surface of the sheet.

3. A machine for roll forming profiled sheet material from flat sheet material as claimed in either one of claims 1 or 2 characterized in that the guides sets (G.1,G.2) comprise two spaced apart sets of opposed guides (1-2,3-4).

4. A machine for roll forming profiled sheet material from flat sheet material as claimed in any one of claims 1 to 3, characterized in that the guides sets (G.1,G.2) comprise two spaced apart roll sets, each roll set (1-2,3-4) comprising two opposed cylindrical rolls (1,2,3,4).

5. A machine for roll forming profiled sheet material from flat sheet material as claimed in claim 4, characterized in that the first set of transverse profile forming rolls (C1.A) comprise a set of two opposed rolls (12,13), a first roll (13) having a central portion (13,1) which has a larger diameter and side portions (13,2) on each side which are concical. tapering towards a smaller diameter away from the central portion (13,1), a second roll 12 having a central portion (12,2) and side portions (12,1) which are conical, initially tapering towards a larger diameter away from the central portion (12,2) and then in outermost portions (12,3) tapering towards a smaller diameter.

6. A machine for roll forming profiled sheet material from flat sheet material as claimed in claim 5, characterized in that the central portion (12,2) of the second roll (12) is freely rotatable, the other portions (12,1;12,3;13,1;13,2) of both rolls (12,13) being driven.

7. A method of rolling sheet material which has a first surface which will be roll formed to have a central ridge (11), characterized in that the sheet is caused to flex in a curve which is concave on the said first surface of the sheet, in the longitudinal direction and where the sheet has the longitudinally extending concave curve, a general concavity on the same said first surface in a transverse direction, modified by lordosis (10) longitudinally in line with the ridge (11).

Drawing