US 3151947 A
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Oct. 6, 1964 A. J. HASTINGS 3, 7
CORRUGATED SHEET Filed NOV. 16, 1961 5 ShGGtS -Shee't l INVENTOR. ALLAN J HASTINGS ATTORNEY Oct. 6, 1964 A. J. HASTINGS 3,
CORRUGATED SHEET Filed Nov. 16, 1961 3 Sheets-Sheet 2 FIG.4
qlllllll/llllllll INVENTOR 32 a 30 ALLAN J. HASTING'S 1 Fl 8 50% f g ATTORNEY United States Patent 3,151,947 CORRUGATED SHEET Allan J. Hastings, Los Angeles, Calif., assignor to The Boeing Company, Wichita, Kane, a corporation of Delaware Filed Nov. 16, 1961, Ser. N 152,764 Claims. (1. 29-489) My invention relates to a new corrugated sheet material of novel construction including the formation of semipyramidal corrugations rather than conventional untapered corrugations.
The sheet material is useful in large spans, such as 50 feet, and in cantilevered structures, such as may be found in roofs of buildings. It also applies to panels used in buildings wherein the corrugated configurations may extend the full length of a panel or may be only a few inches long repeated in series from end to end of a panel. A primary objective of the invention is to provide better structural characteristics in corrugated panels for the above described applications. This is achieved by the use of triangles, in two-dimensional terms, or by the use of semi-pyramidal forms built up by such triangles, in threedimensional terms, which may be said to be inherently strong configurations.
Other objectives include: to provide a pleasing sheet appearance adaptable for architectural use in exposed areas; to provide maximum strength to size and weight, and maximum strength to cost; to devise a corrugated structure having considerable flexibility in design application; to devise a prefabricated structural element to reduce building erection costs; to provide a construction economically manufactured and easily handled, including the ability to be stacked in an envelope of minimum size for transportation and storage.
Further advantages and objectives of my invention will be understood from the following description and from the drawings in which:
FIGURE 1 is a top perspective view of a specific embodiment of my new corrugated sheet.
FIGURE 2 is a bottom perspective view of two corrugated sections integrally formed.
FIGURE 3 is an end view of the sheet.
FIGURE 4 is a plan view of the lines of ridges and grooves as they would appear if a corrugated sheet of the invention were flattened or indicating where folds would be made in a flat sheet to produce my corrugated sheet.
FIGURE 5 is a plan View showing a first corrugated sheet and portions of another sheet joined by connecting means, and indicating a tieing or supporting plate.
FIGURE 6 is an enlarged perspective view of a connecting member and portions of a plate.
FIGURE 7 is an enlarged fragmentary view, partly in section, showing the joining of two sheets by the connecting member of FIGURE 6.
FIGURE 8 is a view similar to FIGURE 7 using a modified connecting member.
FIGURE 9 is a top View of corrugated sheet of the invention fanned into an annulus.
FIGURE 10 is a top perspective view of a portion of the annulus of FIGURE 9.
INTRODUCTION One application of the invention is for roofs or other span or cantilevered structures where costs can be reduced and facility of design can be furthered if the materials are particularly adapted for spanning and cantilevering. Structures other than thin-shell assemblies require sections as deep or deeper than 4 feet, depending on dead-load material stresses, for clear-spanning distances as great as 50 feet. Such deep sections have little use other than form- Fatented Get. 6, 1964 ing the structural members and housing heating ducts and wiring.
Thin-shell construction follows the stress curve and allows greater span with less depth. A disadvantage of various thin-shell constructions previously used is the extensive fabrication required to produce the finished prodnet. This automatically raises the cost per unit area.
Spans no greater than 12 feet cause little difiiculty, but the greater the span beyond this general limit the more difiicult the fabrication and the deeper the section required in roof construction. Whereas lift slabs, curtain walls, and modular aluminum panels have good application as prefabrications and labor-saving systems to minimize the cost of erecting buildings, minimizing roof costs has remained a difficult area.
The present sheet metal assemblies are adapted to span relatively long distances with minimum material. All the material is structural instead of being partly only a covering. This means that the major load carried is live load instead of dead-load of the structure itself.
As before indicated, the corrugated construction is usable not only in roofs but in smaller constructions, such as wall panels, and the lower limit is in applications where the corrugated pattern repeats itself from end to end of a panel every several inches. Such an application would include luggage racks for aircraft where it is desirable to maximize spans and minimize material bulk and weight. In some designs the appearance may be as much a consideration as structural characteristics and the corrugated sheet of the present invention is believed to be of pleasing appearance.
The standard sheet may be 4' x 8 and the standard material may be aluminum. However, the length and width may be considerably larger for some applications depending on the lengths and widths of available sheet material to be formed and the availability of large size machines, such as presses, capable of forming such longer lengths. The corrugated sheet can be made of various materials such as aluminum, low-grade steel, resin-impregnated Fiberglas, wood pulp and plastics. One production method for metal is the use of progressive doubleacting dies. A form or mold is used with Fiberglas wood pulp and plastics.
FIGURES 1-5 Corrugated sheet 20 may be formed from flat sheet or may be molded in corrugated shape, as normally would be done when the material is Fiberglas wood pulp or plastic. FIGURE 4 can be interpreted as showing the lines on which a flat sheet should be folded or as showing what a material corrugated when formed would look like if flattened. In the flat condition the lines 1-12 in FIG- URE 4 represent the tops of ridges and the bottoms of grooves and they represent the lines on which fiat sheet material would be bent to form corrugations.
When a corrugated sheet is viewed in flattened condition or when a corrugated sheet is examined in top and bottom views: (i) serially odd lines, 1, 3, 5, 7, 9, l1 would be substantially parallel; (ii) serially even lines 2-, 4, 6, 8, i9, 12 interfingered therewith would substantially intersect the odd lines i.e., line 2 would intersect lines 1 and 3 etc. (if the ends of the sheets shown were chopped off, the lines in the material would not intersect although extensions of the lines would intersect); (iii) the even lines would form a substantially continuous zigzag; (iv) non-adjacent even lines would be substantially parallel, i.e., lines 2, 6 and 10 would be substantially parallel to each other and lines 4, 8 and 12, would be substantially parallel to each other. For
Tr-ademark of Owens-Corning Fiberglas Corp. of New York, N.Y.
purposes of convenience of description in the specification and claims, serially odd and even lines are described; but. this does not mean that numbering must start on the first line at the side edge of a panel, e.g., the series may be considered to start at the second line or another convenient, applicable line on the face of the corrugated Alternate lines that are parallel would be considered the odd lines.
In the corrugated condition of sheet 20: (i) odd lines are the tops of ridges on a first side of said sheet and are the bottoms of grooves on the second side of said sheet; (ii) even lines are the bottoms of grooves on said first side of said sheet and are the tops of ridges on the second side of said sheet; and (iii) each odd line and the adjacent even lines together form three-dimensional outlines which are ridges on said first side of said sheet and are grooves on said second side of said sheet and which are of V configuration transversely of said corrugation-s and which taper substantially to zero longitudinally of said corrugations, the adjacent three-dimensional outlines being juxtaposed and being faced in opposite directions longitudianlly of said corrugations with pointed ends and broad ends of adjacent three-dimensional outlines juxtaposed.
Another way of describing the corrugated sheet is to say:
(a) The corrugations 21 are formed by a series of juxtaposed identical three-dimensional outlines forming ridges on the upper surface of the sheet. Lines 4, and 6 form 'a three-dimensional outline which is a ridge on the upper surface in FIGURE 1 and a groove on the lower surface in FIGURE 2.
(b) The three-dimensional outline is of V configuration transversely of the corrugations and tapers to zero longitudinally of the corrugation, e.g., planes normal to lines 4, 5 and 6 show V configurations and lines 4, 5 and 6 taper to zero or intersect at the right hand side in FIGURE 1, forming tapered ridges on the upper surface of the sheet and tapered grooves on the lower surface of the sheet. Adjacent juxtaposed three-dimensional outlines face in opposite directions longitudinally of the corrugations. The three-dimensional outlines could be termed semi-pyramids in that each is a half of a pyramid (laid on its side as viewed) having a four-sided base and great height (in a horizontal direction as viewed) in comparison to the dimensions of the base. (c) The three-dimensional outlines on their lines of meeting form grooves on the upper surface of the sheet and form ridges on the lower surface of the sheet, i.e., lines 4 and 6 are the bottoms of grooves in the top view of FIGURE 1 and are the tops of ridges in the bottom view of FIGURE 2.
The basic two-dimensional elements making up the corrugation are triangles that may be all identical. If a large structure such as a bridge bed were to be formed with this corrugated construction, one method of fabrication would be to transport sufficient numbers of triangular sheet metal plates of identical sizes and to weld them together on the site to form the corrugated structure shown in the present drawing. Triangles are good structural building blocks, i.e., trusses are formed mostly by triangles.
The basic units in three-dimension are semi-pyramids (upright when the sheet is upright) formed from the joinder of two elongated right triangles. A pyramid is one of the strongest structural shapes and the present corrugated sheet may be analyzed as having some of the structural properties of pyramids. Although the corrugations are shown as V configurations formed by planar surfaces, curved, tapered corrugations or channel-shaped tapered corrugations could be used. The V configurations have the best structural properties.
For spanning and cantilevering applications, corrugated sheet 20 is best applied with the top and bottom relationships shown in the drawings (rather than inverted). The
3. bottom surface 22 is fiat (see FIGURE 3) and the upper surface 24- may be said to be saddle-shaped in having more height at its ends than in the middle. The flat surface 22 is adaptable for bonding of a skin thereto.
The sheet material has various applications other than for roofs. As a highway or airstrip base, the sheet material can be laid directly on level ground and then asphalt or concrete placed over it. It has various uses as panels in products. Sheets can be used for vertical structural walls, but the choice may be dictated as much by appearance as by structural considerations. In use for bridges, a covering such as concrete may be poured over the sheet and it is possible to use the sheet as a form to be removed after the concrete is set.
In roof applications a sprayed material, such as acoustical plaster for insulation and fire-proofing, can be applied on the bottom surface. A coating also can be applied to the upper, outer surface, i.e., thin gauge aluminum should have a protective coating as against hail.
FIGURE 2 and 20". This is because the forming of the upper saddle surface tends to pull in the upper end edges so that the end surfaces tend to be non-vertical.
It will be understood that the over-all length of two sections iii, 2% may vary between 16 feet or more and 6 inches or less. The width is likewise variable and sheets may be formed of greater Width than length. One unobvious feature of the construction is the capability of varying the density or strength of the corrugated sheet by bringing lines I, 3, 5 closer together or moving them farther apart. If a resilient material is used to form the sheet 20, such broadening or narrowing of the sheet can be done on the construction site and will only require means of uniform stretching or compressing, and means to hold them in such condition, i.e., the shape and the FIGURES 5-8 FIGURE 5 shows a construction in which sheets 20" and 20"" are separate and are joined together by connecting members 30. Various types of connecting means could be used. The connector 30 in FIGURE 6 has good strength characteristics in relation to its weight. It has three side walls and has internal flanges 32 directed normally to the side walls. Connectors 30 can be cast or can be fabricated from metal stock by welding. Connectors 30 are secured by bolts 34 to a plate 36. If sheets 26 and 20 are joined in the middle of a span, plate 36 merely ties connectors 30 together. If instead the joint is at the location of a supporting wall, plate 36 may become the upper flange of an I-beam and have the function of supporting the connectors; and hence the sheets. Connectors 30 also can be used at the end of a corrugated sheet to secure or support the sheet in end assemblies where another sheet is not joined to the first sheet.
FIGURES 7 and 8 show two methods of securing the sheets to connecting member 30. In FIGURE 7 the sheets are abutted on the outside of the connector and secured in place by rivets 40. In FIGURE 8 the side walls of connector 3i) are formed with recesses 42 receiving the edges of the sheets which may be adhesively bonded in place. It will be understood that there. are many other possible ways to secure sheets together, to hold the corrugations against unfolding, and to support the assembly.
The semi-pyramid structural shapes, of course, are made stronger by connectors 30 which, in effect, complete the semi-pyramid base or bridge across the V transverse outline. If the corrugations are formed by a process and with a material not forming a precise enough shape, the installation of connectors 36 can bring the bases of the corrugations to proper configuration. The corrugated material can be made resilient with the intention of varying density and strength by spreading or bringing together the corrugated ridges and grooves as a function of the connecting means, i.e., as the upper angle of connector 30 in FIGURE 6 is reduced, the corrugated structure will be compacted to a denser, higher load carrying condition, and the reverse will occur as the upper angle of connector 30 is increased.
The ends of adjacent corrugated sheets, of course, could be merely lapped, in the manner that ordinary corrugated sheet is used on a pitched roof; but such lapped construction would not take full advantage of the structural properties of my corrugated sheet. It is significant that conventional corrugated sheet is usually used on a roof merely as a covering contributing little to carrying loads in fact being primarily a dead-load, that must be added to the other loads a supporting structure must carry. My corrugated sheet commonly will have the opposite application: it will be the primary load carrying member for a roof or the like.
FIGURES 9-10 FIGURES 9 and 10 show the fanning of the sheets shown in the previous figures into partly or completely annular structures. The minimum size of the opening 59 in the annulus is determined by the maximum compacting of the corrugated sheet about the opening. As the ridges and grooves on the perimeter of the annulus are made sharper (on the right-hand side in FIGURE 10), more corrugated sheet Will be required and the structure about the annulus opening (on the left-hand side in FIGURE 10) will become denser. The perimeter of the annulus can be brought to nearly planar condition if little load is to be carried and can be sharply grooved if sizable loads are to be carried. Further variations in density can be accomplished by corrugating a partly annular sheet on radial rather than strictly parallel lines.
The sheet from which the annulus is formed would have great width to form an annulus by one piece and the annulus is more likely to be formed from several sheets joined at their edges. There are many ways of securing the edges such as by welding, lapping and riveting or by connecting with special connectors. Normally the an nular structure will be substantially or completely cantilevered and the assembly is well adapted for such application as the densest structure is in the center where the maximum load will be carried. Whereas it is possible to mold the material into the annular form, it commonly will be formed by bringing together one edge of corrugated sheet such as is shown in FIGURE 1 and spreading the other end. Depending on the resiliency of the material, partly a function of the nature of the material and partly a function of the material thickness, it would be possible to both out-fold the sheet for erection and to in-fold the structure for disassembly, in the manner of a fan or umbrella, to permit reuse.
The corrugated sheet is believed to meet the design objective of lower total cost in erecting buildings and the like, to provide individual structural sheets which can be made in a size to be readily handled by one man, to minimize erection time, to maximize structural capability versus weight, and to provide flexibility of usage and adaptability to functional architectural design. The construction is susceptible of being constructed of high quality materials to form permanent structures and being con- 6 structed of low cost materials such as paper, fabric, and plastics for temporary uses.
Having thus specifically described my invention, I do not Wish to be understood as limiting myself to the precise details of construction shown, but instead wish to cover those modifications thereof which will occur to those skilled in the art from my disclosure and which fall within the scope of my invention, as described in the following claims.
1. A sheet material structure forming at least part of an annulus by fanning corrugated sheet material having the following configuration before fanning:
(a) a series of juxtaposed corrugations formed in said corrugated sheet material by a series of juxtaposed identical three-dimensional outlines forming ridges on a first side of the sheet and forming grooves on the second side of said sheet,
(b) each three-dimensional outline being of V configuration transversely of the corrugations and tapering substantially to zero longitudinally of the corrugations with adjacent juxtaposed three-dimensional outlines faced in opposite directions longitudinally of the corrugations, and
(c) said three-dimensional outlines on their lines of meeting forming grooves on said first side of said sheet and forming ridges on said second side of said sheet.
2. An annular sheet material structure having a series of radially directed, juxtaposed corrugations, comprising:
(a) said corrugations being formed by a series of juxtaposed three-dimensional outlines forming ridges on a first side of the sheet material and forming grooves on the second side of said sheet material,
(b) each three-dimensional outline tapering substantially to zero longitudinally of the corrugations with adjacent juxtaposed three-dimensional outlines tapering in opposite directions longitudinally of the corrugations, and
(c) said three-dimensional outlines on their lines of meeting forming grooves on said first side of said sheet and forming ridges on said second side of said sheet.
3. An annular sheet material structure having a series of radially directed, juxtaposed corrugations, comprising: at least part of the corrugations being tapered, corruga tions tapered in a first direction along the corrugations being interfingered with corrugations tapered in the opposite direction along the corrugations.
4. The improvement in an article formed of sheet material configured by a plurality of corrugated sections arranged serially longitudinally of said article and each of said sections having a series of juxtaposed corrugations, comprising:
(a) said corrugations of each of said sections being formed by a series of juxtaposed identical threedirnensional outlines forming ridges on an upper surface of said sheet material and forming grooves on a lower surface of said sheet material,
([2) each of said three-dimensional outlines being of V-shaped configuration transversely of said corrugations and tapering substantially to zero longitudinally of said corrugations with adjacent said juxtaposed identical three-dimensional outlines being faced in opposite directions longitudinally of said corrugations,
(c) said juxtaposed identical three-dimensional outlines on their lines of meeting forming grooves on said upper surface of said sheet material and forming ridges on said lower surface of said sheet material,
(d) connecting means adjacently connecting said corrugated sections together to form a sheet of material, said connecting means including a plurality of transversely aligned triangular connecting members positioned on said lower surface of said sheet material, member disposed beneath and connected to said transeach of said triangular connecting members being dis- Versely aligned triangular connecting members.
posed in a longitudinally aligned pair of said grooves formed by each of said three-dimensional outlines References Clted 111 the file 0f thls Patent in said adjacent corrugated sections, and 5 UNITED STATES PATENTS (e) fastening means securing said adjacent corrugated sections to said triangular connecting members. ggifi :5 3 5. The improvement in an article as set forth in clalrn 2,963,128 Rapp Dec- 6, 1960 4, further comprising a transversely extending support