FR2831906A1 - REINFORCED WOODEN STRUCTURE, FRAMEWORK, BUILDING THUS EQUIPPED AND MANUFACTURING METHOD - Google Patents

Abstract

The invention relates to a wood-reinforced structure comprising several beams (2, 3, 4, 6, 7) which are constructed from at least three wood boards (16, 17, 18), two external boards (16, 17) and a central board (18, 19, 21, 22), said boards being assembled to one another. The aforementioned external boards (16, 17) are positioned on either side of the central board (18) and said central board (18) is positioned at the junction zones which form an intersection (8, 9, 11, 12, 13, 14) between at least two beams (2, 3, 4, 6, 7). The central wood board (18, 19, 21, 22) is inserted fully into the housing (23, 24, 26) which is disposed in each of the two external wood boards (16, 17).

Description

<Desc / Clms Page number 1>

REINFORCED WOODEN STRUCTURE, FRAMEWORK, BUILDING THUS
MANUFACTURING TEAM AND METHOD
The present invention relates to a reinforced wooden structure.

 The present invention relates to a frame equipped with a reinforced wooden structure.

 The present invention also relates to a building having a frame equipped with a reinforced wooden structure.

 The present invention also relates to a method for manufacturing and assembling a reinforced wooden structure.

 Wood is a material widely used in construction with which it is possible to produce a whole series of load-bearing systems with their own mechanical properties enabling them to support all levels and all types of loads. The different load-bearing wooden systems are posts and beams, triangular systems also called trusses, articulated systems, gantries, beam grids, shells and elements functioning as plates, for the main ones.

 The invention relates to the production of a reinforced wooden structure with parallel or farm members, which has high mechanical characteristics, makes it possible to reduce production costs and is easily adaptable according to the characteristics desired for each particular application (load to support, dimensions of the structure, ...).

State of the art
Numerous proposals have been made for the realization of the assembly knot forming an intersection between at least two beams of triangulated wooden systems, whether they are parallel members or triangle-shaped.

 We know from US-4. 891.927 a reinforcement of the intersection node of beams by a metal piece inserted in a notch formed symmetrically between two boards. This reinforcement is provided with nails or pins which sink into each of the two boards starting from the part itself.

<Desc / Clms Page number 2>

 Such a solution is very expensive, because it requires a force and factory mounting of the node. This solution eliminates the possibility of an artisanal assembly on the site itself, and an easy adaptation according to the works to be carried out. Furthermore, it is not entirely satisfactory in that the resistance of the knot is dependent on the section of the wooden planks.

 We know from CH-467. 402 and the FR-2. 303.128 a reinforcement placed in beams which are in one piece at the level of the intersection node. The reinforcement is inserted into a simple slot made for its passage. Metal fittings are also provided to maintain the assembly.

 However, these solid woods of large section are relatively expensive. The problems of solid woods are also the deformations and cracks which appear with drying, made more difficult when the sections increase. This type of wood is generally used undried.

 We know from WO-00/32. 891 an economic realization of beams by structures made up of boards nailed to each other to recompose larger sections from wood of small section. A reinforced wooden structure consists of several beams constructed from at least three planks. The two outer planks and the central plank are assembled one on the other, the two outer planks being placed on either side of the central plank. In addition to the central planks, reinforcements are positioned at the junction zones forming an intersection between at least two beams.

 A first drawback of these reinforced structures is the presence of a given odd number of planks, which gives successive increments of thicknesses lacking flexibility. Another disadvantage is that the central boards and the reinforcements must constantly keep the same thickness for the same structure. Another drawback is that the location, positioning and fixing of the various reinforcements and central boards prove to be relatively complex and imprecise, since it is a longitudinal association without blocking points. Another drawback is that central boards and reinforcements give a large number of components for the same farm, which generates high manufacturing costs and increased assembly times.

<Desc / Clms Page number 3>

Summary of the invention
One of the main problems that arises is that of being able to absorb the maximum force flux which is located at the level of the supports, intersections and diagonals, in order to simultaneously resume flexions, traction, compressions and shears.

 A second problem is to succeed in reducing the number of components, for the same reinforced wooden structure.

 A third problem is to provide for tracking, positioning and automatic fixing of the different central boards.

 A fourth problem is to develop a process for manufacturing reinforced structures which allows the possibility of artisanal assembly on the site itself, and easy adaptation depending on the works to be carried out.

 A reinforced wooden structure is made up of several beams constructed from at least three planks, two external planks and a central plank, assembled one on the other, the two external planks being placed on either side of the central plank, the central plank being positioned at the junction zones forming an intersection between at least two beams.

 According to the invention, the reinforced structure is characterized in that the central board is inserted in a housing formed by two recesses each formed in one of the two outer boards.

 The housing is preferably arranged symmetrically in the two outer planks, so that the two recesses have the same depth.

Particularly favorably, the beams of the reinforced structure include a number N of central planks and a number N + 1 of external planks. The N central boards can then be inserted in a number N of housings in the N + 1 external boards.

 In another exemplary embodiment, the beams further comprise two additional planks disposed on each of the visible faces of the two planks being the outermost. In yet another exemplary embodiment, the beams comprise N central planks and N + 1 external planks which are assembled at

<Desc / Clms Page number 4>

 N central planks and N + 1 external planks, the N central planks being inserted in N housings provided in the N + 1 external planks.

 Interestingly, the central board or boards have a thickness different from the outer boards. The material of the central board or boards can be chosen, alone or as a mixture, from the group comprising Kertopuu panels (D or other glued microlame panels with high mechanical performance.

 According to a second aspect of the invention, a frame is characterized in that it is equipped with a reinforced wooden structure as described above.

 According to a third aspect of the invention, a building is characterized in that it comprises a frame as described above.

 According to a fourth aspect of the invention, a method for manufacturing and assembling a reinforced wooden structure described above is characterized in that it comprises the steps consisting in providing a recess in each of the two boards outside at the junction zones forming an intersection between at least two beams, positioning a central board in the recess, and assembling the two outer boards and the central board.

 The assembly of the reinforced wooden structure is preferably carried out by nailing, screwing, stitching and / or by gluing.

limitatif de réalisation, en référence aux dessins schématiques annexés, dans lesquels : - la Figure 1 représente une vue latérale d'une ferme ; - la Figure 2 représente une vue en perspective éclatée d'une ferme à trois couches ; - la Figure 3 représente une vue en perspective éclatée d'une ferme à cinq couches ; Description of the drawings
The invention will be well understood and its various advantages and various characteristics will become more apparent from the following description, from the example not

limiting of embodiment, with reference to the appended schematic drawings, in which: - Figure 1 represents a side view of a farm; - Figure 2 shows an exploded perspective view of a three-layer farm; - Figure 3 shows an exploded perspective view of a five-layer farm;

<Desc / Clms Page number 5>

 Figure 4 shows a longitudinal sectional view of a three-layer beam; Figure 5 shows a longitudinal sectional view of a five-layer beam; Figure 6 shows a longitudinal sectional view of a seven-layer beam; - Figure 7 shows a longitudinal sectional view of a five-layer beam, in an alternative embodiment; Figure 8 shows a longitudinal sectional view of a seven-layer beam, in an alternative embodiment; - Figure 9 shows a longitudinal sectional view of a six-layer beam, in an alternative embodiment; Figure 10 shows a side view of a simple beam farm; Figure 11 shows a side view of a gantry with two joints; - Figure 12 shows a side view of a lattice with parallel members; Figure 13 shows a side view of a single-slope half-farm; Figure 14 shows a side view of a truncated farm; - Figure 15 shows a side view of a farm with rolled up ties; - Figure 16 shows a side view of a gantry with three joints; and Figure 17 shows a side view of a faceted farm.

detailed description
The first reinforced structures in the shape of a triangle 1, or firm (see Figures 1 to 3 and 7 to 14) are generally used to make the roof frames and allow the slope to be given to the latter. The elements involved in the realization of such structures consist of two rafters 2, a entry 3, two diagonals 4, a punch 6 and two struts 7. Such assemblies rest on supports (not shown) arranged at each end of entry 3.

 The different crossbow elements 2, the entry 3, the two diagonals 4, the punch 6, and the two struts 7 are beam-shaped and are designated in the following description by the common expression beam. Each beam is constructed from boards nailed to each other to compose larger sections.

<Desc / Clms Page number 6>

 There is thus a knot or intersection 8 between crossbowmen 2 and entry 3, an intersection 9 between crossbowmen 2 and punch 6, an intersection 11 between crossbowmen 2 and diagonals 4, an intersection 12 between crossbowmen 2 and struts 7, an intersection 13 between entry 3 and struts 7 and an intersection 14 between entered 3, diagonals 4, and punch 6.

 To make these structures, the elementary planks used in the constitution of each beam are massive planks whose section is generally between 15 cm and 30 cm in width for 3 cm to 10 cm in thickness, not excluding other special dimensions. Furthermore, with thin boards, for example of the order of 3 cm to 5 cm, it is possible to carry out an artificial drying under conventional conditions. The length of said boards can be variable and depends on the structures to be produced and will for example be between 4 m and 12 m. Longer planks can be obtained by abutting with multiple glued finger joints.

 For structures that can represent a very high resistance, individual planks can be recomposed into larger sections. The boards can also be in glulam or micro-laminate of Kertopuu type (D or other equivalents.

 The set of beams used in the formation of such a structure consists of three elementary boards 16, 17 and 18, for example nailed together (see Figures 2 and 4). The beams include two external planks 16 and 17 and a central board 18. The central board or plate 18 constitutes a reinforcement.

 According to the invention, the central boards 18 allow, in a simple way, to reinforce the junction intersections between these beams, and more particularly allow to reinforce the most stressed intersections. The reinforcements 18 are therefore positioned at the level of the central layer, which allows double shearing of the nails passing through with respect to the reinforcement which would be exposed outside the structure, as is often the case. The length of the reinforcements 18 is independent of the length of the outer boards 16 and 17.

 An upper reinforcement 19 is placed at the intersection 9 between rafters 2 and punch 6. A lateral reinforcement 21 connects the intersection 11 between rafters 2 and diagonals 4, the intersection 12 between rafters 2 and struts 7 at the intersection 13 between entered 3 and struts 7. Since on the left and right of the same farm 1, there are intersections 11 12 and 13 in duplicate, we use two reinforcements right and

<Desc / Clms Page number 7>

 left 21. A lower reinforcement 22 is placed at the level of the intersection 14 between enter 3, diagonals 4, and punch 6.

 The lateral plank reinforcement 21 can take up the bending moment and the local shear generated by the two internal beams, for example the diagonal 4 and the strut 7 compressed. The lateral reinforcement 21 therefore reinforces the intersection 11 with respect to bending and local shears which are important mechanical components of the intersection system. The lateral reinforcement 21 acts as an additional rib. It should be noted that the lateral reinforcement 21 is offset relative to the node 8 between the crossbowman 2 and entered 3.

 According to the invention, the various reinforcements 19, 21 and 22 are inserted into housings. These housings are each formed by two recesses, each being cut in one face of each of the two outer planks 16 and 17. The association of two recesses constitutes a housing. The length of the housings is independent of the length of the outer planks 16 and 17.

 These recesses have a depth substantially equal to half the thickness of the various reinforcements 19, 21 and 22. Thanks to this characteristic, it is therefore no longer necessary for the three elementary boards 16, 17 and 18 constituting each beam to be of same thickness.

 Housing 23 is thus provided at the upper end of the rafters 2 and the punch 6, at the intersection 9. These housing 23 are intended for the upper reinforcement 19. Housing 24 is thus provided over a portion of the length of the crossbowmen 2, at the upper end of the diagonals 4, over the entire length of the struts 7 and over part of the entry 3, at the intersections 11, 12 and 13.

The struts 7 will simply have a thickness less than that of the boards 16 and 17. These housings 24 are intended for the lateral reinforcements 21. Housings 26 are thus provided at the lower end of the diagonals 4, at the lower end of the punch 6 and at the center of the entry 3, at the intersection 14. These housings 26 are intended for the lower reinforcement 22.

 The reinforcements 19, 21 and 22 and their positioning by embedding are always calculated to take up the shear forces generated by the two diagonals 4 arriving at the intersection, to resume the traction and compression in the axis of the diagonals 4 and to reinforce the crossbowmen 2 at intersections to resume bending and local compression simultaneously. These reinforcements 19, 21 and 22 of

<Desc / Clms Page number 8>

 plate type have very high rigidity and work in both directions of the plane. However, in some cases, the reinforcements have a main direction of absorption of the forces, and they can be reoriented differently from the board for better efficiency.

 In the manufacturing process, the recesses corresponding to the housings 23, 24 and 26 are produced automatically, for example by digital machining of the boards 16 and 17. The boards 16 and 17 are thus always planed. An antifungal treatment and a color stain can be applied during machining.

 During assembly, the recesses in the housings 23, 24 and 26 of the boards 16 and 17 allow automatic positioning, without any marking, of the reinforcements 19, 21 and 22, without having to identify the positions of the latter, unlike the state of technique. This constitutes an appreciable saving of time and a precision of assembly and reliability of the reinforced structure. The production plant can deliver complete farms with all of the cut and numbered parts, which a craftsman can then assemble on his own.

 The connection between the various boards 16 and 17 and reinforcements 19, 21 and 22 is obtained by nailing, screwing or broaching. Such a solution makes it possible to withstand greater forces, the reinforcements 19, 21 and 22 at the level of the intersection zones 9, 11, 12, 13 and 14 increasing the nailing zones. In addition, the wood being nailed dry, there is no more deformation of the compound section. This nailing is adapted so as not to cause the central reinforcements 19, 21 and 22 to crack.

 From a mechanical and structural performance point of view, the positioning of the reinforcements 19, 21 and 22 inside the housings 23, 24 and 26 is favorable for the transmission of forces. We can save on connecting means, such as nails, screws, bolts, ... In addition, the reinforcements 19, 21 and 22 are prefixed by adjustment, their bonding to the bottom of the recesses in the housings 23, 24 and 26 is possible. This bonding of the reinforcements 19, 21 and 22 may be sufficient to assemble and produce the entire wooden structure. These central reinforcements 19, 21 and 22 in planks are therefore of high performance in terms of their assembly.

 The reinforcements 19, 21 and 22 are produced from a panel constituted by a wooden structural element of the micro-laminated plywood type. It is a laminated veneer of spruce obtained by peeling. These veneers, about 3 mm thick, are hot glued, wire on wire, under high pressure with a phenolic resin resistant to

<Desc / Clms Page number 9>

 severe weather. The fibers are arranged in the longitudinal direction. The plywood is marketed by the company Finnforest under the name Kertopuu @ or Kertog. The reinforcements 19, 21 and 22 have a thickness conventionally between 27 mm and 39 mm. Other microlame or glued plywood panels with high mechanical performance can also be used. Thus, the corresponding recesses in the housings 23, 24 and 26 will have a depth respectively between 13.5 mm and 19.5 mm.

 In an alternative embodiment (see Figures 3 and 5), from a beam structure comprising three elementary planks, it can also be envisaged to produce beams with five planks. The set of beams 2, 3, 4, 6 and 7 entering the configuration of a reinforced structure of the firm type consists of five elementary boards 27, 28, 29, 31 and 32, for example nailed together.

 In this variant, the expression “outer plank” applies to all the planks 27, 29 and 32 which are not reinforcements, even if they are found included within the reinforced structure. The same technical characteristics of the reinforcements and of the boards already described above are used for the beam farm comprising three boards, with two upper reinforcements 19, four lateral reinforcements 21 and two lower reinforcements 22.

 The reinforcements 28 and 31 are thus doubled and are then positioned respectively between the first board 27 and the second board 29 and between the second board 29 and the third board 32. The board inserted in the center 29 will be machined on its two faces to spare the recesses necessary for positioning the reinforcements 28 and 31.

 In another alternative embodiment (see Figure 6), from a beam structure comprising five elementary planks, it can also be envisaged to produce beams with seven planks. The set of beams 2,3, 4,6 and 7 entering in the configuration of a reinforced structure of the firm type consists of seven elementary planks 33,34, 36,37, 38,39 and 41, for example nailed between they.

 In this variant, the expression external board applies to all boards 33, 36, 39 and 41 which are not reinforcements, even if they are found included within the reinforced structure. We use the same technical characteristics of the reinforcements and planks already described above for the beam farm

<Desc / Clms Page number 10>

 comprising three or five boards with three upper reinforcements 19, six lateral reinforcements 21 and three lower reinforcements 22.

 The reinforcements 34, 37 and 39 are thus tripled and are then positioned respectively between the first board 33 and the second board 36, between the second board 36 and the third board 38 and between the third board 38 and the fourth board 41. The boards inserted in the center 36 and 38 will be machined on their two faces to provide the recesses necessary for positioning the reinforcements 34, 37 and 39.

 If we extrapolate the invention, the structure is characterized in that the number of reinforcements being positioned at each intersection in the boards is equal to N, the number of external boards being equal to N + 1. Since the N reinforcement planks are inserted in the N + 1 external planks, the total thickness of the beams will be equal to the sum of the thicknesses of the N + 1 external planks. This is advantageous for large frames intended for agricultural or industrial buildings with free spans of 40 m to 60 m.

 In an alternative embodiment (see Figure 7), from a beam structure comprising three elementary planks 16,17, and 18 (according to Figure 4), it can also be envisaged to produce beams with five planks. The set of beams 2,3, 4,6 and 7 entering the configuration of a reinforced structure of the firm type consists of five elementary boards 16,17, 18,42 and 43, for example nailed together. The two boards 42 and 43 are fixed to the respective free visible external face of the two outermost boards 16 and 17.

 In this variant, the expression “outer board” applies to all the boards 16 and 17 which are not reinforcements 18, even if they are found included within the reinforced structure. The same technical characteristics of the reinforcements and planks already described above are used for the beam farm comprising three planks, with an upper reinforcement 19, two lateral reinforcements 21 and a lower reinforcement 22.

 In another alternative embodiment (see FIG. 8), from a beam structure comprising five elementary planks 27, 28, 29, 31 and 32 (according to FIG. 5), it can also be envisaged to produce beams with seven boards. The set of beams 2,3, 4,6 and 7 entering the configuration of a reinforced structure of the firm type consists of seven elementary planks 27,28, 29,31, 32,42 and 43, by

<Desc / Clms Page number 11>

 example nailed together. The two boards 42 and 43 are fixed on the respective free visible external face of the two outermost boards 27 and 32.

 In this variant, the expression external board applies to all the boards 27, 29 and 32 which are not reinforcements 28 and 31, even if they are found included within the reinforced structure. The same technical characteristics of the reinforcements and planks already described above are used for the beam truss comprising three or five planks with two upper reinforcements 19, four lateral reinforcements 21 and two lower reinforcements 22.

 In an alternative embodiment (see Figure 9), from a beam structure comprising three elementary planks 16,17, and 18 (according to Figure 4), it can also be envisaged to produce beams with six planks. The set of beams 2,3, 4,6 and 7 entering the configuration of a reinforced structure of the firm type consists of six elementary planks 16a, 17a, 18a, 16b, 17b and 18b, for example nailed together. It is in fact a first substructure comprising three elementary boards 16a, 17a, and 18a, which is assembled with a second substructure comprising three elementary boards 16b, 17b, and 18b.

 In this variant, the expression external board applies to all the boards 16a, 16b, 17a and 17b which are not reinforcements 18a and 18b, even if they are found included within the reinforced structure. The same technical characteristics of the reinforcements and planks already described above are used for the beam truss comprising three or five planks with two upper reinforcements 19, four lateral reinforcements 21 and two lower reinforcements 22.

 For reasons of structural efficiency, a firm cross-sectional view must always be symmetrical with respect to the axis of the most central board, that is to say, and depending on the case, the reinforcement or the central board. which is not a reinforcement. In the case of several reinforcements, they will in principle have the same thickness. In the case of an odd number of reinforcements, the central reinforcement could have a thickness and the sides taken two by two could have another thickness. This symmetry makes it possible to avoid parasitic forces, such as torsions of the truss, which would veil on its most rigid side.

 The reinforcement of the intersections and of the wooden structure in accordance with the present invention is adaptable indifferently to the two main families of triangulated wooden structures called structures with parallel members and said trusses.

<Desc / Clms Page number 12>

 triangulated. The structure with parallel members is used for example for bridges or horizontal floor structures.

 These possible structures are a truss with simple beams (see Figure 10), a gantry with two joints (see Figure 11), a trellis with parallel members (see Figure 12), a half-sloping single-truss (see Figure 13), a truss truncated (see Figure 14), a farm with rolled up ties (see Figure 15), a gantry with three joints (see Figure 16), a faceted farm (see Figure 17).

 They include a structure substantially related to the farm described in detail above. Where appropriate, they are placed on two vertical uprights 44. They include as many upper reinforcements 19, lateral 21 and lower 22 as there are possibilities of intersections between the beams 2,3, 4,6 constituting.

 The present invention is not limited to the embodiments described and illustrated.

Many modifications can be made, without departing from the framework defined by the scope of the set of claims.

Claims (11)

 CLAIMS 1. Reinforced wooden structure made up of several beams (2,3, 4,6, 7) constructed from at least three planks (16,17, 18), two exterior planks (16,17) and a plank central (18,19, 21,22), assembled one on the other, the two external boards (16,17) being placed on either side of the central board (18), the central board (18) being positioned at the junction zones forming an intersection (8,9, 11, 12,13, 14) between at least two beams (2,3, 4,6, 7), characterized in that the central board (18 , 19, 21, 22) is inserted into a housing (23, 24, 26) formed by two recesses each formed in one of the two outer boards (16, 17). 2. Reinforced structure according to claim 1, characterized in that the housing (23,24, 26) is formed symmetrically in the two outer planks (16,17). 3. Reinforced structure according to claim 1 or 2, characterized in that the beams comprise N central planks (34,37, 39) and N + 1 external planks (33,36, 38,41), the N central planks (34 , 37, 39) being inserted in N housings in the N + 1 external boards (33,36, 38,41). 4. Reinforced structure according to one of the preceding claims, characterized in that the beams further comprise two additional boards (42,43) arranged on each of the visible faces of the two boards being the outermost (16,17) . 5. Reinforced structure according to claim 3 or 4, characterized in that the beams comprise N central planks (18 a) and N + 1 external planks (16a, 17a) assembled with N central planks (18b) and N + 1 external planks (16b, 17b), the N central boards (18a, 18b) being inserted in N housings in the N + 1 external boards (16a, 17a, 16b, 17b). <Desc / Clms Page number 14>  6. Reinforced structure according to one of the preceding claims, characterized in that the central board or boards (18) have a thickness different from the outer boards (16,17). 7. Reinforced structure according to one of the preceding claims, characterized in that the material of the central board (s) (18) is chosen, alone or as a mixture, from the group comprising Kertopuug panels or other microlame or plywood panels bonded to high mechanical performance. 8. Frame, characterized in that it is equipped with a reinforced wooden structure (1), according to one of claims 1 to 7. 9. Building, characterized in that it comprises a frame according to claim 8. 10. A method for manufacturing and assembling a reinforced wooden structure (1) according to one of claims 1 to 7, characterized in that it comprises the steps consisting in: - providing a recess (23,24 , 26) in each of the two outer planks (16,17) at the level of the junction zones forming an intersection (8,9, 11, 12,13, 14) between at least two beams (2,3, 4,6, 7); - Position a central board (18,19, 21,22) in the recess (23,24, 26); and - assemble the two outer planks (16,17) and the central plank (18,19, 21,22). 11. Method according to claim 10, characterized in that the assembly of the reinforced wooden structure (1) is carried out by nailing, screwing, stitching and / or by gluing. Submitter: Jean-Luc SANDOZ Agent: Cabinet LAURENT ET CHARRAS