WO1999023324A1

WO1999023324A1 - Toothed metal grid structure, particularly for finishing manufactured products and building works for civil or industrial use

Info

Publication number: WO1999023324A1
Application number: PCT/IT1998/000291
Authority: WO
Inventors: Denis Robert Gemmani
Original assignee: La Stamp Press S.P.A.
Priority date: 1997-10-31
Filing date: 1998-10-23
Publication date: 1999-05-14
Also published as: AU9759998A; ITTV970151A1; ITTV970151A0; IT1297288B1

Abstract

Toothed metal grid structure, particularly for finishing manufactured products and building works for civil or industrial use, of the electroforged type and made up of a group of toothed and parallel welded bars with transversal profiles, parallel to one another, making up a steel reticular structure comprising some square or rectangular meshes.

Description

DESCRIPTION TOOTHED METAL GRID STRUCTURE. PARTICULARLY FOR FINISHING MANUFACTURED PRODUCTS AND BUILDING WORKS FOR CIVIL OR INDUSTRIAL USE Technical Field The present invention has for object a toothed metal grid structure, particularly for finishing manufactured products and building works for civil or industrial use. Background Art The grid surfaces obtained in metal are known. These, are always more widely spread and used in different fields, such as the building of common works for the urban sector, such as road drain wells for draining the meteoric waters, for covering water channels, and so on, the civil engineering works intended for the industrial production sector not excluded, as in the making of pathways, platforms in general, paving, and the like. All these are needs specifically required by special regulations, which are not only national, as for instance the ones concerning the food sector. Notoriously, by the structural viewpoint, the grids may be made up of a series of parallel and coplanar, one adjacent to the other, metal plates and small plates, whose upper ones are transversally fixed for forming the meshes, with a second series of lower metal bars, which being the bearing ones, are previously notched in the intersection points, for then being all together perimetrally closed by an eventual frame or edge. At the beginning, the mainly used process in the making of said grid elements, was of the manual type, it being a work with a rather discontinuous character and thus an handicraft work. This latter essentially consisted in placing on a contact bench the first series of equidistant bars, for then transversally placing a second series of transversal bars over the first ones, thus intersecting them. These first ones were of type the previously notched for some millimetres, according to the dimensions corresponding to the distance between centres provided between bar and underlying bar. Once the positioning is over, the group was closed by a second contact plane and finally pressed by known machines. The drawbacks found in the above mentioned solution, consisted of that a certain amount of labour was necessary, requiring long working times. Of course, in addition to a very high final cost of the product, the thus obtained grid did not have sufficient quality characteristics for being effectively put on the market in series, being subjected to deformations, which were also due to an objective lack of uniformity of the meshes. The markets needs proved the inadequacy of such systems, the most advanced ones for the making of metal grids and the like included, as in patent n. 1 222 326, and this both due to the low production capacity and to the low flexibility, because of the different grid sizes to be constantly put on the market. Secondly, sometimes, slight manufacturing faults, such as the presence of deformations mainly in correspondence of the bearing plate, a fault which is probably due to the whole grid moulding cycle, were noticed. The problem though, mainly due to the mentioned solution, common to other solely pressed grid solutions, derives from that the grate structure, mainly in time, may be subjected to yielding caused by the dynamic loads weighing on the same because of the effects caused by the vehicles and pedestrians circulation, definitely endangering the safety. The most recurring structural faults, thus, may consist of the bearing plates inclination, up to their possible detachment, or at least of a localised ground buckling. Finally, the electroforged grid is also known. This latter, decidedly considered the most recent of the first ones, presently has different uses, but, just because of the structural characteristics, it seems more affected with load limits than the pressed grid, for which, vice versa, there is a wider possibility of use conditions. In this case, the electroforged grid, is made up of a series of equidistant bearing plates, having no perpendicular notches, concerned at the top and transversally by a series of round but also square elements. Both the round and the square, though, have with no doubt a lower inertia respect to the metal strap, which instead in the pressed grid, intersects the bearing plate. For what concerns these grid solutions, it may be stated that they do not seem enough optimised yet, mainly in that they have rather wide meshes, while the transit surfaces, being smooth, may be very dangerous. Furthermore, it may be noticed that in the production processes, mainly the transversal plates up to now used, were never satisfactory from the quality viewpoint, because both the manufacturing and the surfaces caused some trimming or struts, and as such they were very dangerous both in their handling, and in case of accidental interference of body parts with the surface of the same ones. Purpose of the present invention is also that of obviating the above mentioned problems. This and other purposes are reached with the present invention according to the characteristics as in the enclosed claims, solving the mentioned problems by means of a toothed metal grid structure, particularly for finishing manufactured products and building works for civil and industrial use, of the electroforged type and made up of a group of toothed and parallel bars welded with transversal profiles, parallel to each other, making up a reticular steel structure comprising some square or rectangular meshes. Thus, through the considerable creative contribution whose effect creates an immediate technical progress, different advantages are obtained. For what concerns a first aspect, mainly of functional character, it may be noticed that the grid has good characteristics of dynamic load resistance. Secondly, the grid elements production process may be further speeded up, considerably reducing the execution times and minimising the dead times, with an optimal quality standard. A further aspect, is that of making a heel-proof grid, thanks to the very small mesh size, at the same time obtaining an anti-skid surface, because the transit plane is made up of plates, whose upper edge is toothed. Finally, a third and last advantageous aspect, is that a safety grid is obtained, because the toothed rolled bars used, and the transversal profiles do not have sharp corners and the production process does not cause any trimming or struts. These and other advantages will appear from the following detailed description of embodiment preferred solutions with the aid of the enclosed schematic drawings whose execution details are not to be considered as limitative, but only as examples. Figure 1., shows, in perspective, an electroforged type metal grid portion. Figures 2. and 3. respectively show a side and top view of one of the toothed bars which make up the metal grid shown in Figure 1. Figure 4. and 5. respectively show a side and top view of at least one of the transversal profiles which make up the metal grid shown in Figure 1., in this case having a round section. Figures 6. and 7. respectively show a side and top view of a variation to the transversal profiles of Figs. 4. and 5., which make up the metal grid shown in Figure 1., in this case providing a twisted square section. Figure 8., is a plan view, that is of the transit plane, of the electroforged type metal grid shown in Figure 1. Figure 9., is a view of the lower surface of the electroforged type metal grid shown in Figure 1. Figure 10., is a side view of the electroforged type metal grid shown in Figure 1. Finally, Figure 11., shows a front view of the electroforged type metal grid, as always shown in Figure 1. Description of a possible execution. Also referring to the figures, it may be noticed that a metal grid structure (A), of the electroforged type, makes up a substantially reticular structure, preferably in steel, of the type with square or rectangular meshes (al ). The reticular structure, is particularly suitable for civil uses, such as the garages and repository entrances, for making steps and staircase footpaces. But also for industrial uses, such as grids, overland footpaths, jetties, gangways and towers, not excluding its use in agriculture, such as for collecting drains, footpaths, various shelves, for instance for discharging and collecting grain. More in detail, said grid structure (A), is made up of a plurality of bearing plate-bars (1 , 1 1 , In), preferably in steel, parallel to one another, to each of which at least one common side provided with a series of teeth corresponds, obtaining a continuous indentation (3). More in detail, said indentation (3) concerns the upper and longitudinal edge of each flat standing bar (1 , 11 , In), which being in contact with the ground on the other side, obtains a transit surface (a) on the extrados, characterised in having square or rectangular meshes (al). The equidistant junction of said toothed bearing bars (1 , 1 1 , In), is ensured by a series of transversal crossing profiles or bars (2, 21 , 2n), preferably also in steel, which may be made up of profiles with round section, (see. Figs. 4. and 5.) or alternatively of twisted profiles with square section, (see. Figs. 6 and 7.). Also in this case, said transversal crossing profiles or bars (2, 21 , 2n) are parallel and preferably equidistant to one another, so that all the intersection points between the bearing toothed bars (1 , 1 1 , In) and the transversal profiles (2, 21 , 2n), result as welded on the opposite side respect to that of the indentation (3).

Claims

CLAIMS 1. A metal grid structure, particularly for finishing manufactured products and building works for civil and industrial use and to cover man-holes, made up of a series of parallel bearing plate-bars (1 , 1 1 , In) held by crossing orthogonal bars (2, 21 , 2n), which are encased and welded, creating a rectangular reticular structure (a, al ), characterised in that the upper border of said bearing plate-bars (1 , 1 1 , In), is provided with a series of electroforged teeth realizing a continuous indentation (3). 2. A toothed metal grid structure, according to previous claim, characterised in that said encasing and welding amongst said bearing plate- bars (1, 1 1 , In) and said crossing orthogonal bars (2, 21 , 2n), is made up in the opposed surface of said continuous indentation (3) of said bearing plate- bars (1, 11, In), by respective opposed indentation to encase and weld said crossing orthogonal bars (2, 21, 2n). 3. A toothed metal grid structure, according to previous claims, characterised in that said crossing orthogonal bars (2, 21 , 2n), are made up of round section rods. 4. A toothed metal grid structure, according to previous claims 1 , 2, characterised in that said crossing orthogonal bars (2, 21 , 2n), are made up of square-section twisted rods.