Patent GB-472233-A (GB)
Title: Improvements in and relating to sheet-like structural elements suitable for use in the construction of roofs, walls and the like
IPC: E04C2/04
Filed: 1936-03-16
Abstract: 472,233. Making roofing &c. elements. LAFFAILLE. B. March 16, 1936, No. 7921. Convention date, March 14, 1935. [Classes 83 (ii) and 83 (iv)] [Also in Group X] The faces of a sheet-like metallic structural element suitable for use in the construction of roofs, walls and the like are surfaces of revolution, the generators of which are convex towards the axis of revolution. Each surface may be a hyperboloid of revolution, or the internal part of a toroid. The elements may be constructed of a plurality of metal units or strips built upon a light framework g<1>, Fig. 4, which is shaped to conform to the surface of the complete element and is bounded by two meridians m1, n1, and m2, n2, and two parallels m1, m2, and n1, n2. The framework g<1> which is reinforced along one edge g may be in the form of either a light wooden member, or a series of crossed wires c which are connected together at their points of intersection and are fixed at their ends to the part g and to the other edges of the framework. The first metal unit or strip is then placed on the framework g<1> parallel to the edge m1, n1, and a second strip is laid parallel to the first and overlapping it slightly; the two strips are then welded or riveted together by a machine which is moved parallel to the edge m1, n1, and these strips are then displaced in the direction of the edge m2, n2, to make space for a third strip which is connected to the second strip by the welding or riveting machine. This operation is continued with successive strips until the first strip reaches the edge m2, n2, the four edges of the completed element being then fixed to edge members. The element may also be built up from a number of identical units or strips of metal which are fixed together when placed in position in the structure. The element s shown in Fig. 5, is bounded by two meridians m1, n1, and m<1>, n<1> and by two parallels m1, ml and n1, n<1> and is made up of a number of units as shown by the dotted lines. These units are positioned on a support which conforms to the shape of the finished element and they are fixed together and to strengthening members at the edges in the form of rolled steel joists or the like. Alternatively, the support may be movable about an axis x, x<1> and have a width equal to the width of the element (i.e. the distance m1 n1) and a length equal to the width of two units of the element (i.e. the distance m<1>, m<3>). The first two units m1, m2, p2, p1 and p1, p2, n2, n1 are first placed on the support and are fixed at the edges to rolled steel joists; the next pair of units is then positioned and fixed at the edges to the joists and the first pair of units. The support is then displaced about the axis x x<1> to the extent of the width of one unit, and a further pair of units is secured in position. Further units are similarly added until the element is complete. The element may also be formed of a number of units bounded by equidistant parallels and meridians of the element. The units may be in the form of quadrilaterals obtained from a hyperboloid of revolution and bounded by generators, or parallels to generators, of the hyperboloid.