US 3421353 A
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Jan. 14, 1969 v. G. FRANC 3,421,353 METHOD AND APPARATUS FOR MAKING CORRUGATED BUILDING SHEETS Original Filed Dec. 15, 1964 Sheet. of 2 Fig. I
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Jan. 14, 1969 v, FRANC 3,421,353
METHOD AND APPARATUS FOR MAKING CORRUGATED BUILDING SHEETS OriginalF'iled Dec. 15, 1964 Sheet 2 of 2 A M;- *M F2 3 x I A 3g MQ k \A\}\3BZ 4, 44 77 7 73 77% fi 23, WW 4 k 1' 4 43 ms 54 4 54 Q71 1 2 1 V; 5 I 237 Vz I: 77] i nwavrae VICTOP G. FPA/VC AL? A Q ATTORNEY United States Patent 3,421,353 METHOD AND APPARATUS FOR MAKING CORRUGATED BUILDING SHEETS Victor G. Franc, Wireton, Pa., assiguor to H. H. Robertson Company, Pittsburgh, Pa., a corporation of Pennsylvania Original application Dec. 15, 1964, Ser. No. 418,426. Di-
vided and this application Oct. 12, 1967, Ser. No. 683,059
US. Cl. 72-181 Int. Cl. B21d /08; B21b 1/24 5 Claims ABSTRACT OF THE DISCLOSURE Cross-references to related applications This is a division of application Ser. No. 418,426, filed Dec. 15, 1964, now abandoned, and assigned to the assignee of the present invention.
This invention concerns an improved corrugated building sheet and a method for making the same.
The corrugated building sheets with which this invention is concerned are those which have a plurality of relatively fiat crests and alternating flat valleys parallel with the crests and having essentially flat sloping webs diverging from the crests to the adjacent valleys. Such corrugated building sheets are shown, for example, in US. Patents 1,982,243, 1,936,228, 2,696,281, 2,789,530. Heretofore such corrugated sheets have been available in lengths up to about 12 feet. While warping tendencies were manifested in these prior corrugated building sheets, the adverse effects of those warping tendencies could be overcome because of the relatively short lengths of such sheets.
More recently corrugated building sheets have become available in longer lengths. Sheets of feet, feet, and even feet length are commercially available today. Warping tendencies in these long sheets are irregular and difficult to overcome. Dissimilar warping of successive corrugated building sheets make it difficult to nest such sheets together for minimum volume packaging. Side-byside and end-to-end overlapping of warped building sheets is difiicult, and the resulting building wall is frequently unattractive.
The warping tendency in corrugated sheets may arise from a variety of metallurgical reasons, for example, coldrolled metal sheets usually are thicker in the center than at the edges, a phenomenon known in the metal industry as high crown metal. The crown of the metal sheet may be precisely centered or may range for some distance over both sides of the sheet center. However even metal sheets with no detectable crown present warping tendencies upon corrugation. Metal sheets with nonuniformities, hardness differential temper variations, temperature differentials and inequalities resulting from aging phenomena have been advanced as reasons for warping tendencies in corrugated building sheets.
Without regard to the origin of the warping tendencies, the present invention provides a method and apparatus for making corrugated building sheets which are substantially free of warping manifestations.
According to the present invention, a pair of the sloping webs of the corrugated building sheet, one web on each side of the center of the sheet, are initially prepared as substantially flat sloping webs similar to all of the other sloping webs of the corrugated sheet. After those two selected ones of the sloping webs have been formed, and before any of the laterally displaced sloping webs are formed, the two selected ones of the sloping webs are passed between a set of forming rolls to modify the configuration of the two selected sloping webs from a substantially fiat configuration, as formed, to an arcuate configuration. Thereafter the corrugated building sheet is completed according to prior art practices by forming the laterally displaced crests, valleys and sloping webs as required. The resulting corrugated building sheets are essentially free of any manifestations of warping tendencies even in lengths of 40 feet.
The invention will be more fully illustrated and described in the following detailed description by reference to the accompanying drawings in which:
FIGURE 1 is a perspective view of the corrugated building sheet of this invention;
FIGURE 2 is a side elevation view of milling apparatus adapted to roll form the present building sheets; and
FIGURES 3, 4, 5, 6, 7 and 8 are fragmentary crosssection views taken along the lines 3-3, 4-4, 5-5, 66, 77 and 88 respectively of FIGURE 2.
Referring to FIGURE 1 there is illustrated a corrugated building sheet 10 having a plurality of crests 11 and alternating valleys 12 which are connected by substantially fiat sloping webs 13. Such corrugated building sheets normally terminate with fragmentary sloping webs 14 along each edge. The term crests and the term valleys are relative since frequently these flat surfaces are identical in dimensions, differing only in which set of surfaces (the crests) is closer to the viewer than the other set (the valleys). By reversal of a corrugated sheet, hence, the surfaces become interchanged. The corrugated sheet 10 has four surfaces 11 which have been designated crests and has five surfaces 12 which have been designated valleys. Clearly, if the corrugated sheet 10 were turned over, the five surfaces 12 could be accurately designated crests and the four surfaces 11 could be accurately designated valleys.
A typical metal building sheet has crests 11 and valleys 12 1.625 inches wide and separated by 3.5 inches centerto-center. The plane of the crests is 1.5 inches apart from the plane of the valleys. The over-all width of the building sheet is about 31 inches. Such building sheet has 4 crests and 5 valleys, as shown in FIGURE 1. The sloping webs 13 form an angle 44 to 45 with the plane of the crests.
According to this invention, two of the sloping webs 13a, 13b are changed from a substantially flat configuration as formed, to an arcuate configuration in such manner that the arcuate configuration is virtually undetectable visually as a departure from the substantially flat configuration of the remaining ones of the sloping webs 13. The arcuate sloping webs 13a, 13b are formed into the corrugated building sheet during its fabrication after the sloping webs 13a, 131) have been fully formed in a substantially flat configuration and prior to the formation of any succeeding laterally displaced sloping webs 13.
Process FIGURE 2 presents a side elevation view of a roll forming line for the assembly of the present corrugated building sheets. A coil 20 of metal sheet 21 is fed to a cutting means 22. Cut-to-length sheets 23 are passed sequentially through rolling stands 3, 4, 8, 5, 6 and 7 to form the present corrugated building sheets 23 which are nested together in a shipping stack 24 after formation. Each of the rolling stands 3, 4, 5, 6, 7 is commonplace in the corrugated building sheet rolling industry. Cross-sections through these metal stands are presented in the drawings FIGURES 3, 4, 5, 6 and 7. Throughout the drawings 3, 4, 5, 6, 7 the top rolls are designated by the letter A and the bottom rolls by the letter B. Each of the rolls in any stand is designated further by sequential subscripts from left to right.
As shown in FIGURE 3, the metal sheet 23 passes between rolls 3A (above) and rolls 3B and 3B (below). As a result the metal sheet 23 has formed therein a center crest C and two flat sloping webs W and W In that condition the sheet 23 passes to the station 4, where, as shown in FIGURE 4, the sheet passes beneath rollers 4A 4A and 4A and above rollers 4B and 4B The roll 4A serves principally to align the sheet 23 whereas the rollers 4A and 413 cooperate to form the valley V and the sloping web W Likewise the rollers 4A and 4B cooperate to form the valley V and web W Additional crests, valleys and sloping webs are introduced into the metal sheet 23 in stations 5, 6 and 7. It will be observed that, in station 7 (FIGURE 7), the rollers 7A and 7B form a crest C and a fragmentary sloping web W Similarly the rollers 7A and 7B form the crest C and the fragmentary sloping web W A corrugated building sheet formed by passage through stations 3, 4, 5, 6 and 7 would conform with prior art practices and would be susceptible to severe warpage, especially in long lengths. The additional forming step of this invention is illustrated in FIGURE 8 wherein a pair of forming rolls 8A and 8A is attached to an upper shaft while a pair of corresponding rolls 8B and 8B is attached to a bottom shaft. The rolls 8A and 8A have a convex configuration whereas the rolls 8B and 8B have a concave configuration. As the metal sheet 23 enters the nip of the rolling stand 8, it has the configuration seen in FIGURE 4, i.e., it contains a crest C two valleys V and V and four substantially flat sloping webs W W W and W The rolls in rolling station 8 perform Work on the sloping webs W and W by changing the form from a substantially flat sheet to an arcuate surface identified in FIGURE 8 as SW and SW It will be observed that the lateral portions of the metal sheet 23 (displaced from the arcuate sloping ribs SW and SW are essentially unaltered from the initial flat condition, i.e., the lateral portions have experienced no corrugating stresses.
It should further be observed that the sloping webs W and W have been completely formed as substantially flat surfaces prior to the conversion of those surfaces to an arcuate configuration SW and SW as shown in FIGURE 8.
It should further be observed that the two arcuate surfaces SW and SW are disposed equidistant from the center crest C i.e., there is one of the arcuate sloping surfaces on each lateral half of the finished corrugated building sheet. In the event extremely wide corrugated building sheets are manufactured, it may be desirable to provide more than two of the arcuate sloping surfaces in the sheet. The two arcuate surfaces SW and SW illustrated in FIGURE 8 correspond to the arcuate webs 13a and 13b of the finished building sheet as shown in FIG- URE 1. In FIGURE 8, the sloping surfaces SW and SW laterally adjoin the central valleys V and V Further, those two sloping surfaces SW and SW are formed from initially substantially flat sloping webs W and W which were converging, i.e., which were nonparallel.
1. In rolling mill apparatus for fabricating from a fiat sheet of metal a corrugated building sheet having plural fiat crests and alternating plural flat valleys parallel with the said crests, and having essentially flat sloping webs diverging from each of the said valleys to the adjacent ones of the said crests, said apparatus including a rolling machine, means for advancing a said fiat sheet of metal to and through said rolling machine, said rolling machine having sequential roller formers for forming first a central one of the said crests with the laterally adjacent webs; thence for forming the laterally adjacent valleys and their laterally adjacent webs; thence for forming the laterally adjacent crests and their laterally adjacent webs; thence sufficient additional roller formers to complete the said corrugated building sheet; the improvement in said rolling mill apparatus comprising:
a pair of convex roller formers and a pair of opposed concave roller formers positioned in said rolling machine sequentially after the roller formers which provide the central ones of the said plural valleys and prior to the last ones of the roller formers in the said rolling machine,
said convex and concave roller formers being adapted to alter at least one of the already-formed webs from a flat configuration to a curved configuration, whereby the resulting corrugated building sheet is substantially free of warpage.
2. In a fabricating process for making from a fiat sheet of metal a corrugated building sheet having plural flat crests and alternating plural flat valleys parallel with the said crests and having essentially flat sloping webs diverging from each of the said valleys to the adjacent ones of the said crests, the said process including sequential rolling said sheet of metal through roller formers for sequentially forming a central crest and its adjacent webs; thence the laterally adjacent valleys and their laterally adjacent webs; thence the next laterally adjacent crests and their laterally adjacent webs and so forth until the entire corrugated sheet is formed, the improvement in the said process comprising:
after the said central crest and its laterally adjacent valleys have been formed and before the outside webs have been formed, altering the surface configuration of at least one of the already formed webs from a flat-surface to a curved surface and thereafter completing the forming of the said building sheet without altering the said curved surface of the said already-formed web, whereby the resulting corrugated building sheet is substantially free of warpage.
3. The process of claim 2 wherein the said sheet of metal has a nominal thickness of 20 to 26 gauge and has an organic coating applied to at least one surface thereof.
4. The process of claim 2 wherein the said corrugated building sheet has four valleys and five crests and wherein the said already-formed webs are those laterally adjacent to the two interior valleys.
5. The process of claim 2 wherein the said flat-surface of the said already-formed webs is curved to present a concave surface when viewed from that side of the said sheet nearest the said valleys.
References Cited UNITED STATES PATENTS 1,485,917 3/1924 Harter 72l81 X 1,900,722. 3/1933 Manske et a1. 72l80 X 2,708,958 5/1955 Crafton 72-181 X 3,051,214 8/1962 Rutten 72181 MILTON S. MEHR, Primary Examiner.
U.S. Cl. X.R. 72366