EP1094170A1 - Grating with a frame of elements not connected with the grid and method of manufacture - Google Patents

Abstract

The metallic duck board grid has a frame formed by a trellis with two sets of support leaves (2) and spacers (3). The frame has a section formed by the re-curved ends of the support leaves. The leaves can be of metal or plastics or composites. The spacers can be of plain sheet or bar material or metal strips. The panel can be rectangular with two opposed sides formed by the lateral support leaves and the two other sides formed by the re-curved sections Claims include a method of making the grid

Description

The invention relates to the technical field of gratings.

Gratings have been known for a long time and have been made in various materials including wood, metal, polymers.

The invention relates more particularly, but not exclusively, to metal gratings.

Conventional metal gratings are most often made at from assembled metal strips, expanded metal, profiled sheets openwork.

The invention relates more particularly to gratings obtained by assembly of slats.

Conventionally, these gratings comprise two types of elements: bearing elements or supporting bars and spacers called bars, inserted bars or blades, most often transverse to the supporting bars and therefore sometimes referred to as "sleepers".

The supporting bars are most often elongated, the spacers may be elongated or have folds or ribs extending between the load-bearing bars.

Spacers can extend perpendicular to the longitudinal axis load-bearing bars or be inclined with respect to this axis, so as to form so-called slatted gratings.

The assembly of the spacers to the load-bearing elements is most often achieved by the interpenetration of deep notches arranged from one of the sections of load-bearing elements and spacers.

These notches extend over a fraction, for example half, of the height of load-bearing elements and spacers.

The interpenetration of the notches can be obtained by crimping, each notch of the supporting elements having a bottom portion of width less than the thickness of the spacers.

Other assembly methods such as electro-forging, keying or welding, pressure welding are also used.

Such gratings are used in particular in construction, chemical, agro-food industries or so-called offshore structures "Offshore", for example, for the realization of floors, walkways, on roofs, access and maintenance galleries, technical false ceilings, false walls, safety grids, passageways, pontoons, scaffolding, artificial floors for animal husbandry, floor painting or sandblasting booths, gutter or trench, stair treads, scraper, ventilation grille, grilles trees, doormats, solar shading, siding, railings.

Such gratings can withstand heavy loads and the lights limited by load-bearing bars and spacers allow the evacuation of water, sludge and other materials to be eliminated.

In some applications, several thousand m2 can be formed by installing gratings.

We already know in the prior art, many embodiments of such gratings or elements of gratings.

Reference may be made, for example, to patent applications in France N ° 2,768,302, 2,725,927, 2,709,646, 2,708,646, 2,690,472, 2,675,175, 2,672,917, 2,638,380, 2,553,692, 2,542,044, 2,519,115, 2,492,630, 2,473,677, 2,398,857, 2,369,499, 2,366,418, 2,360,034, 2,355,239, 2,265,031, 2,183,385, 2,153,824, 2,117,747, 2,082,574, 1,594,243, 1,524,103, 1,518,878, 1,440,727, 1,433,127.

Conventionally, the lateral edges of the metal gratings obtained by assembling load-bearing blades and spacers are defined by a frame welded to these bearing blades and spacers.

Such welding can lead to local corrosion resistance lower, as well as deformations of the grating.

We already know seamless assembly processes for the frame of gratings with load-bearing blades and spacers.

We can refer to document FR-A-2 258 233 which describes an assembly to the press in a single operation, without welding the frame to the mesh of the gratings. This assembly uses U or J profiles forming the sides of the frame, these profiles being crimped into slots in the terminal parts of load-bearing irons and insert bars.

Document FR-A-1 518 878 describes an assembly of the frame to the trellis central of a grating, the elements of the frame comprising stirrups projecting from the internal face of the frame, these stirrups being obtained by stamping cutting. The transverse elements carrying the frame are provided with means allowing locking or jamming on these stirrups.

The methods known in the prior art for assembly without welding frame parts to the central lattice of the gratings with load-bearing blades and spacers are complex and expensive and do not allow great flexibility in the realization of different sizes and shapes of frames.

The invention aims in particular to have an assembly method which does not with no such disadvantages.

To this end, the invention relates, according to a first aspect, to a grating comprising a frame limiting a trellis formed by the assembly of blades load-bearing and spacer elements, this frame being devoid of elements attached to the trellis and comprising at least one section formed by the parts extremities bent by load-bearing blades.

The supporting blades of the trellis can be made of a material chosen from the group comprising metal alloys such as steels or aluminum alloys, polymeric materials, composite materials, or any other equivalent material.

The elements forming spacers can be chosen from the group comprising solid sheets, solid bars and in particular bars inserts, perforated sheets, expanded metal strips.

In one embodiment, the grating is said to be reversible or "cardboard", "half-iron", the elements forming spacers being of shape, dimensions and arrangement substantially identical to the carrying blades.

In this embodiment, the grating can be seen as not comprising as load-bearing blades.

In one embodiment, the grating is of generally rectangular shape, two opposite sides of the frame being formed by two lateral support blades, the other two sides being formed by the curved end portions of blades carriers.

The curved end portions of the carrying blades forming said frame section may or may not extend along a common plane, said section frame can be for example curved.

In some embodiments, the curved end portions of the blades carriers forming said frame section are provided with end tabs and through holes, each end tab of a carrier blade coming to the less to be lodged in the through hole of another load-bearing blade which is the closest or not.

In some embodiments, the end tabs are hook-shaped protruding towards the inside of the trellis.

The invention relates, according to a second aspect, to a method of realization of a grating as presented above.

When the carrying blades are metallic, this method comprises a folding step of the end parts of these carrier blades so as to form said frame section.

When folding, the end tabs of the carrying blades can be inserted in the through holes provided for this purpose in the other blades carriers.

In one embodiment, this insertion is carried out by force.

If necessary, this insertion can be completed by a deformation of the end tabs so as to bring them projecting towards the inside of a mesh of the trellis or pressing against a load-bearing blade.

For the curved end portions of the bearing blades forming one or more several sections of the grating frame, friction blocking or hooking of these blades together can thus be obtained.

When the bearing blades are made of polymer or composite material, the curved end portions of the load-bearing blades can come from molding or injection.

In this case, a snap of the curved end tabs of the blades carriers in the holes of bearing blades, whether adjacent or not, can be provided, so as to reinforce the rigidity of the formed frame section.

The method of manufacturing gratings further comprises a step of assembly of the carrier blades to the elements forming spacers, this step of assembly being carried out by a method chosen from the group including welding, cold pressure welding, keying, electroforging, crimping or any other equivalent process.

The choice of assembly process depends in particular on the conditions of intended use for the grating as well as the materials used. The step of assembling the carrier blades to the elements forming spacers can be performed at least in part at the same time as the folding of the end parts of the carrying blades.

The process can be carried out using metal sheets provided surface treatment such as zincing or any other equivalent process.

• la figure 1 est une vue en perspective d'un bord latéral d'une structure de caillebotis, selon un mode de mise en oeuvre du procédé de l'invention ;
• les figures 2 et suivantes sont des vues de détail d'autres modes de réalisation de caillebotis obtenus selon l'invention.

Other objects and advantages of the invention will appear during the following description of embodiments, which description will be made with reference to the accompanying drawings, in which:

• Figure 1 is a perspective view of a side edge of a grating structure, according to an embodiment of the method of the invention;
• Figures 2 and following are detailed views of other embodiments of gratings obtained according to the invention.

The grating 1 represented in FIG. 1 comprises supporting blades 2 assembled with spacers 3.

The supporting blades 2 and the spacers 3 can be made of an alloy metallic such as steels or aluminum alloys, polymer material or composite material, or any equivalent material.

The carrying blades 2 and the spacers 3 can be made in one same material or not.

In particular embodiments, the carrier blades 2 and the spacers 3 are made of steel provided with a surface treatment such as zincing, hot-dip galvanizing or any other equivalent process.

The carrying blades 2 are, in the embodiment shown, strips of materials extending in a first direction D1, the spacers 3 being strips of material extending in a second direction D2 substantially perpendicular to D1.

In other embodiments, not shown, the spacers 3 do not are not all parallel to each other and / or are not arranged in a direction perpendicular to D1.

• le terme " hauteur " sera employé en référence à une troisième direction D3 formant un trièdre direct avec les directions D1 et D2 ;
• le terme " épaisseur " sera employé, pour chaque objet concerné, en référence à une direction perpendiculaire à la direction d'élancement de cet objet ;
• le terme " longitudinal " sera employé en référence à la famille de plans définie par les première et deuxième directions D1 et D2 ;
• le terme "transversal " sera employé en référence à la famille de plans définie par les directions deuxième et troisième D2 et D3.

In the rest of the text:

• the term "height" will be used with reference to a third direction D3 forming a direct trihedron with the directions D1 and D2;
• the term "thickness" will be used, for each object concerned, with reference to a direction perpendicular to the direction of slenderness of this object;
• the term "longitudinal" will be used with reference to the family of planes defined by the first and second directions D1 and D2;
• the term "transverse" will be used with reference to the family of planes defined by the second and third directions D2 and D3.

The assembly of the spacers 3 and the carrier blades 2 can be carried out by welding, cold pressure welding, bonding, electro-forging, keying, crimping or any other equivalent means.

In the embodiment shown, the spacers 3 are housed in notches 4 of the carrying blades 2, for example by crimping obtained by cold pressing.

These notches 4 extend over a height h4 substantially equal to or slightly greater than the height h3 of the spacers 3.

• équidistantes selon la première direction D1 ou non ;
• d'épaisseur constante sur toute leur longueur ou non ;
• planes ou ondulées, nervurées ;
• d'épaisseur identique sur toute leur hauteur ou non ;
• d'épaisseur identique entre elles sur toute la surface du caillebotis ou non ;
• disposées suivant des plans transversaux ou inclinés par rapport à ces plans, de sorte à former un caillebotis à lames inclinées ;
• formées par des profilés, par exemple en U ou en V, dont la face supérieure peut être pourvue de reliefs, par exemple antidérapants ou indicatifs d'une direction ;

ces caractères étant pris seuls ou selon les diverses combinaisons possibles.The spacers 3 can be:

• equidistant according to the first direction D1 or not;
• of constant thickness over their entire length or not;
• flat or wavy, ribbed;
• of identical thickness over their entire height or not;
• of identical thickness between them over the entire surface of the grating or not;
• arranged in transverse or inclined planes with respect to these planes, so as to form a grating with inclined blades;
• formed by profiles, for example U or V, the upper face of which may be provided with reliefs, for example non-slip or indicative of a direction;

these characters being taken alone or according to the various possible combinations.

In one embodiment, the spacers are of shapes and dimensions substantially identical to those of the bearing blades and the gratings formed are thus reversible.

In another embodiment, the spacers are parts whose axes pass through the holes of the carrier blades, these holes being, by example, placed halfway up the bearing blades.

The grating shown in Figure 1 is square mesh and defines a plane upper longitudinal P1 and a lower longitudinal plane P2, the upper plane P1 being able to receive loads in the third direction D3.

In other embodiments, not shown, the grating is mesh rectangular, the distance separating two successive carrying blades being greater or not greater than the distance separating two successive spacers.

We now describe the frame of the grating and its method of embodiment, in a first embodiment.

As it appears in Figure 1, this frame is formed, in the first direction D1, by the two end bearing blades and, in the second direction D2, by folding the transverse end edges of the carrier blades.

On their two free end parts, the carrying blades 2 are provided with assembly means 5.

In one embodiment of the method according to the invention, these means of assemblies 5 are made before assembly of the spacers 3 on the load-bearing blades 2.

These assembly means 5 include, in the embodiment shown in Figure 1, a through hole 6 and an end tab 7 arranged on each carrier blade 2.

The end tab 7 of a given first carrying blade of the grating is of such shape and dimensions that it can at least partially penetrate into an opening 6 of a second carrier blade.

This second carrier blade can be immediately close to the first, as shown in Figure 1.

As a variant, this second carrier blade is not immediately close to the first, but is distant from this one by one or more meshes, by example two meshes as shown in Figure 2.

• un premier type dans lequel les lames porteuses sont pourvues sur au moins une de leur partie extrême, d'une bande rabattable supportant la patte d'extrémité 7 et le trou traversant correspondant 6 ;
• un deuxième type dans lequel les lames porteuses sont dépourvues de bandes rabattable.

In such variants, the carrier blades are of at least two types:

• a first type in which the carrying blades are provided on at least one of their end part, with a folding band supporting the end tab 7 and the corresponding through hole 6;
• a second type in which the carrying blades are devoid of folding bands.

• d'un trou traversant 6a ainsi qu'il est représenté en figure 1, ce trou traversant permettant éventuellement l'assemblage avec la patte d'extrémité d'une lame porteuse d'un élément de caillebotis voisin 9 (en pointillés sur la figure 1) ;
• d'une perforation 10, ainsi qu'il est représenté en figure 2,cette perforation facilitant le pliage et formant le cas échéant butée d'appui lors de la mise en place du caillebotis sur un support.

A carrying blade 2a forming one of the angles of the grating element can be provided:

• a through hole 6a as shown in Figure 1, this through hole optionally allowing assembly with the end tab of a carrier plate of a neighboring grating element 9 (dotted in Figure 1 );
• of a perforation 10, as shown in FIG. 2, this perforation facilitating folding and, if necessary, forming a support stop when the grating is placed on a support.

When a carrier blade 2a forming one of the angles of the element of grating is provided with a through hole 6a, this hole can be similar to those provided for the other bearing slats of the grating element (Figure 1), or be of different shape or size.

Another form of through hole 6a is shown in FIGS. 3 and 4, the load-bearing blade 2a being shown not folded in FIG. 3 and as folded in figure 4.

We now refer to FIG. 5, which illustrates another mode of production of a grating element according to the invention.

In this embodiment, the end portions of the carrier blades are folded so as to form at least one edge of the grating element.

In the embodiment shown in FIG. 5, starting from a first edge 11 of the grating element, formed by a carrying blade 2a, and moving towards the opposite edge 12 formed by a carrying blade 2b, it is observed that all of the load-bearing blades are folded in a similar fashion, except for one blade 2c, devoid of folded band.

The folded bands 13a, 13b of the two carrier blades adjacent to this blade 2c are arranged head to tail.

We now refer to Figure 6, which shows, in sectional view partial longitudinal, an embodiment of a frame assembly of gratings according to the invention.

In this embodiment, a stapling effect is obtained in the manner next.

The end tab 7 of a carrier blade 2i is inserted into a hole crossing 6 of a neighboring carrier blade 2j.

This insertion is carried out by folding the carrying blade 2i, its strip folded down 8a thus forming part of the frame of the grating element. The carrying blade 2i is for example at the end of the grating element and in forms an edge 14.

In the embodiment shown, the folded strip 8a is substantially perpendicular to this edge 14.

In other embodiments, not shown, the folded strip 8a is bent at an angle greater than or less than 90 °.

In one embodiment, the end tab 7 has a hook shape such that after folding the strip 8a, this end tab 7 projects inwards of a mesh 15 of the grating.

Alternatively, the end tab 7 is bent inwardly of the mesh 15, when folding the carrier blade 2i or after this folding.

The deformation of the end tab 7 can in particular be a consequence of the folding of the carrier blade 2j, during the contact between the tab end 7 and the edge 16 of the through hole 6 of the carrier blade 2i.

In the embodiments shown, the folded bands of the load-bearing blades are bent at 90 ° to the pitch direction of these blades, so that a substantially rectangular frame is formed for the element of gratings.

In other embodiments, not shown, this folding is carried out according to an angle other than 90 °, this angle being identical or not for each blade carrier.

Curved edges can thus be obtained for the elements of gratings.

Such achievements may be desired for the establishment of gratings around pillars or curved walls for example.

The folding of the end strips of the carrying blades can, in one mode of realization, bring them into contact with a spacer.

If necessary, the supporting blades can be locally thinned to facilitate folding.

A process for producing the gratings presented above will now be described.

• une étape de pliage des parties extrêmes de lames porteuses métalliques de sorte à former ladite section de cadre ;
• une étape d'assemblage des lames porteuses 2 aux éléments formant entretoises 3, cette étape d'assemblage étant réalisée par une méthode choisie parmi le groupe comprenant le soudage, le soudage par pression à froid, le clavetage, l'éléctro-forgeage, le sertissage ou tout autre procédé équivalent.

This process includes:

• a step of folding the end portions of metal support blades so as to form said frame section;
• a step of assembling the carrier blades 2 to the elements forming spacers 3, this assembly step being carried out by a method chosen from the group comprising welding, welding by cold pressure, keying, electro-forging, crimping or any other equivalent process.

In one embodiment, the step of assembling the carrier blades to the elements forming spacers is produced at least in part at the same time as the step of folding the end parts of the carrying blades.

The realization of the framework therefore does not result in a loss of time compared methods of assembling conventional frames.

In addition, the method can be implemented from metal sheets provided with a surface treatment such as electrozincing or any other process equivalent.

Finally, this process does not require any welding and therefore does not cause deformations of the grating.

It has been found by the inventors that such a process allows a gain of more than 20% on the cost price of the gratings, compared to the processes conventional.

This result is all the more remarkable since the metal gratings are, as said above, known for a long time and have been the subject of many developments in the past.

Claims (19)

Grating comprising a frame limiting a trellis formed by the assembly of carrier blades (2) and elements forming spacers (3), characterized in that the frame is devoid of elements attached to the trellis. Grating according to claim 1, characterized in that this frame comprises at least one section formed by the curved end portions of carrying blades. Grating according to claim 1 or 2, characterized in that the carrier blades (2) of the trellis are produced from a material chosen from the group comprising metal alloys, polymeric materials, composite materials, or any other equivalent material. Grating according to any one of claims 1 to 3, characterized in that the elements forming spacers (3) are chosen from the group comprising solid sheets, solid bars, perforated sheets, strips of expanded metal. Grating according to claim 4, characterized in that the elements forming spacers (3) are insert bars. Grating according to claim 5, characterized in that the insert bars are arranged in a direction D2, the bearing blades being arranged in a direction D1 substantially perpendicular to D2. Grating according to claim 4, characterized in that the elements forming spacers are of shapes, dimensions and arrangement substantially identical to those of the carrying blades, the grating thus being reversible and comprising only carrying blades. Grating according to any one of claims 5 to 7 characterized in that the curved end portions of the supporting blades forming said frame section extend along a common plane. Grating according to claim 8, characterized in that it is of generally rectangular shape, two opposite sides of the frame being formed by two lateral carrying blades (2a, 2b), the other two sides being formed by the curved end portions of carrying blades . Grating according to any one of claims 5 to 7, characterized in that the curved end portions of the supporting blades forming said frame section do not extend along a common plane. Grating according to claim 10, characterized in that said frame section is curved. Grating according to any one of claims 1 to 11, characterized in that the curved end portions of the supporting blades forming said frame section are provided with end tabs (7) and through holes (6), each tab of end (7) of a carrier blade coming at least partially to be housed in the through hole (6) of another carrier blade. Grating according to claim 12, characterized in that each end tab (7) of the carrier blades forming said frame section is housed at least partially in the through hole of the carrier blade which is closest to it. Grating according to claim 12, characterized in that each end tab (7) of the carrier blades forming said frame section is housed in the through hole of a carrier blade different from that which is closest to it. Grating according to any one of claims 12 to 14, characterized in that the end tabs (7) are in the form of a hook projecting towards the inside of the trellis. A method of producing a grating as presented in any one of claims 1 to 15 characterized in that it comprises a step of bending the end parts of metal support blades so as to form said frame section. A method according to claim 16 characterized in that it comprises a step of assembling the supporting blades (2) to the elements forming spacers, this assembly step being carried out by a method chosen from the group comprising welding, pressure welding cold, keying, electroforging, crimping or any other equivalent process. A method according to claim 17 characterized in that the step of assembling the carrier blades to the elements forming spacers is carried out at least partly at the same time as the step of folding the end portions of the carrier blades. Process according to any one of Claims 16 to 18, characterized in that it is implemented from metal sheets provided with a surface treatment such as zincing or any other equivalent process.

Images