US 2699599 A
Description (OCR text may contain errors)
Y Jan. 18, 1955 J. A. POTCHEN STRUCTURAL SHEET Fil ed June 8, 1949 2 Sheets-Sheet 2 ll HI l INVENTOR. 6630/? United States Patent STRUCTURAL SHEET Joseph A. Potchen, 'Grand Rapids, IVIich assignor to Haskelite Manufacturing Corporation, Grand Rapids, Mich., a corporation of New York The invention relates to structural sheets or panels.
A desideratum in embossed sheets of the structural type is maximum stiffness or strength against transverse bending stresses on substantially any angular line across the sheet and one object of the invention is to provide an embossed panel or sheet embodying this desideratum.
Another object of the invention is to provide an embossed sheet which is adapted to form the core of a hollow panel and provide the maximum transverse stiffness against bending stresses with lightness in the overall weight of the hollow panel.
Another object of the invention is to provide an embossed panel with a structural formation which can be produced at a low cost and provides maximum transverse stiffness against bending stresses.
Other objects of the invention will appear from the detailed description.
The invention consists in the several novel features hereinafter described and more particularly defined by the claims at the conclusion hereof.
In the drawings:
Fig. 1 is a plan of a sheet embodying embossed formations in accordance with the invention;
Fig. 2 is a section taken on line 22 of Fig. 1;
Fig. 3 is a side elevation of a hollow panel including outer sheets, and a sheet of embossed metal in accordance with the invention;
Fig. 4 is a section taken on line 4-4 of Fig. 3;
Fig. 5 is a section taken on line 5-5 of Fig. 3;
Fig. 6 is a section on an enlarged scale of the border construction in the hollow panel.
The structural sheet embodying the invention as illustrated in Figs. 1 and 2 consists of a sheet of suitable metal, such as aluminum or other suitable material. The sheet is embossed to provide series of areas on both faces of the sheet which are adapted to be bonded to facing sheets to form a hollow panel. The form of the embossed areas is designed to provide maximum structural strength against bending by reason of the contour of and the inter-relation of the embossed areas. These embossed areas are adapted to stiffen the sheet against bending along any line extending across the sheet, such as horizontally, vertically, diagonally, or on any other angular line. The structural sheet is formed from a flat sheet of metal or other suitable material, portions of which are left coplanar to provide areas for bonding the structural sheet to a facing or finishing sheet and the outer faces of the embossed portions are coplanar to provide surfaces to which an opposite facing or finishing sheet may be bonded. The beveled connecting portions between the opposite face portions during the embossing operation are stretched to increase their rigidity while the opposite face portions are left substantially unstretched.
The structural sheet is provided substantially throughout its entire area with embossed areas of like contour. Each embossed area includes a flat face portion 20, four rounded or curved outwardly projecting corners 22, incurved ends 23 between the corners at each end, and incurved side-portions 24 with central bulges 25. Corners 22, ends 23, side-portions 24 and bulges 25 are angular in cross-section between the face-portions 20 and the opposite face of the sheet as indicated at 27. The rounded corners 22 conform in contour or curvature to the incurved side-portions 24, and the incurved ends 23 conform in contour to the bulges 25 and the incurved side-portions 24. The ends and sides of contiguous embossed areas are spaced apart leaving flat portions 27 between them.
The embossed areas are arranged in rows extending crosswise of each other. Each row includes alternate embossed areas which extend crosswise of each other. The embossed parallel areas in one row are staggered relatively to the parallel embossed areas in adjacent rows. This results in providing vertical rows with alternating areas extending crosswise of each other and horizontal rows with alternating embossed area's extending crosswise of one another. Each embossed area is correlated to the contiguous embossed areas so that its incurved ends 23 and portions of its rounded corners 22 will conform to the contiguous incurved side-portions and bulges 25 of contiguous. crosswise arranged embossed portions, and its incurved side-portions 24 and bulges 25 will conform to the incurved ends and rounded corners 22 of contiguous crosswise embossed areas, as illustrated in Fig. 1. As a result transverse bending moments applied to the sheet in any direction will produce stresses on lines which will intersect a plurality of the portions of the embossed areas or of arched or inclined cross-section and curves so as to stiffen the sheet against all such stresses.
In Figs. 3 and 4 of the drawing the embossed sheet functions as a core for a hollow panel which comprises facing sheets 35 and 36 having their margins folded together to form closed edges for the panel and a reinforcing channel bar 37 extending around all of the edges of the panel and fitting between the overlapped edges of the facing sheets and the margins of the embossed core. The embossed sheet extends between the edges of the panel and the facing sheet 35 is bonded by a suitable high strength adhesive to all of the face-portions 20 of the embossed areas. The facing sheet 36 is likewise bonded to the outer face of all of the coplanar portions 27 of the embossed sheet. This construction when formed of aluminum provides a lightweight hollow panel which possesses a high degree of stiffness against bending. It may be advantageously used as a substitute for a panel composed of a solid plywood core with metal facing sheets bonded thereto because the embossed structural core may be fabricated at a low cost and has a high degree of transverse stiffness.
The structural sheet of the invention is adapted for any use in which stiffness against bending is a factor. It also provides a low-cost core for a hollow structural panel. The structural sheet has great advantages when formed of lightweight metal, such as aluminum, but may also be advantageously used for structural sheets or other suitable material, such as plastic, where structural strength and stiffness against bending and cost of production are important factors.
The invention is not to be understood as restricted to the details set forth since these may be modified within the scope of the appended claims without departing from the spirit and scope of the invention.
Having thus described my invention what I claim as new and desire to secure by Letters Patent is:
1. A structural sheet provided with embossed areas, each provided with a face portion, ends, incurved sides and outwardly projecting round corners joining the sides and ends, said ends, corners and sides being beveled in cross-section, the alternate embosed areas extending crosswise of each other, the embossed areas being spaced and correlated so that the sides of each embossed area w ll conform in contour to the ends of contiguous crosswise areas and its ends will conform in contour to the sides of contiguous crosswise extending areas, for stiffening the sheet against transverse bending on substantially any line, the portions of the sheet between the embossed areas being coplanar.
2. A structural sheet provided with embossed areas, each provided with a face portion, incurved ends, incurved sides with central bulges and outwardly projecting round corners joining the sides and ends, said ends, corners and sides being beveled in cross-section, the alternate embossed areas extending crosswise of each other, the embossed areas being spaced and correlated so that the sides of each area will conform in contour to the ends of contiguous crosswise areas and its ends will conform in contour to the sides of contiguous crosswise extending areas, for stiffening the sheet against transverse bending on substantially any line, the portions of the sheet between the embossed areas being coplanar.
3. A structural sheet provided with embossed areas, each provided with a face portion, ends, inset sides and outwardly projecting corners joining the sides and ends, said ends, corners and sides being beveled in cross-section, the embossed areas being arranged in rows with alternate areas extending crosswise of each other, the sid of each alternate embossed area in one row extelghng in one direction conforming in contour to the en s and portions of the corners of contiguous crosswise extending areas, the ends and corners of each of said alternate areas conforming in contour to the sides of contiguous crosswise extending areas, the portions of the sheet between the embossed areas being coplanar,
4 the embossed areas being correlated for intersection by bending stresses and stiffening the sheet against transverse bending on substantially any line.
References Cited in the file of this patent UNITED STATES PATENTS 973,442 Lees Oct. 18, 1910 2,441,476 Ewald May 11, 1948 2,304,718 Swart Dec. 8, 1942 March 24, 1948, issue of Steel, pages 94-97, 119 and 120.