EP1341977A1

EP1341977A1 - Method for making a wooden beam, wooden beam and structure for constructing a building

Info

Publication number: EP1341977A1
Application number: EP01996657A
Authority: EP
Inventors: Claude Schmerber
Original assignee: Dorean Sarl
Current assignee: Dorean Sarl
Priority date: 2000-11-14
Filing date: 2001-11-12
Publication date: 2003-09-10
Anticipated expiration: 2021-11-12
Also published as: WO2002040802A1; ES2239175T3; CA2426468A1; HUP0301385A2; AU2305502A; AU2002223055B2; ATE291135T1; US20040074195A1; FR2816649A1; HUP0301385A3; PT1341977E; DE60109485T2; US7185471B2; JP4033343B2; DE60109485D1; JP2004514076A; FR2816649B1; EP1341977B1; CA2426468C

Abstract

The invention concerns a method for making a wooden beam, a wooden beam and a wooden structure (10) consisting of identical wooden beams (1) comprising each four parallel square rulers (2a, 2b, 2c, 2d) linked by crosspieces (3a, 3b) assembled to said square rulers (2a, 2b, 2c, 2d) with so-called flexible glue forming after drying elastic joints allowing a relative movement between the square rulers (2a, 2b, 2c, 2d) and the corresponding crosspieces (3a, 3b).

Description

METHOD FOR MANUFACTURING A WOODEN BEAM. WOODEN BEAM AND WOOD FRAME FOR THE CONSTRUCTION OF A BUILDING

The present invention relates to: - a method of manufacturing a wooden beam consisting of basic elements defining its edges and forming at least four squares connected by other basic elements forming at least two crosspieces, the squares and the crosspieces being assembled in assembly areas, by bonding their contact areas, - a wooden beam manufactured according to the above process, and - a wooden frame for the construction of a building.

In a known manner in the building field, and more particularly in that of timber frame constructions, the wooden beams are in one piece and cut into the mass, or in glued laminated, or formed by the assembly of basic elements more small dimensions. Monobloc or glued wooden beams are heavy, bulky, difficult to handle, rigid, have a high ecological and economic cost, and tend to crack.

The wooden beams formed by the assembly of basic elements of smaller dimensions make it possible to lighten the frameworks, to facilitate the assembly and to reduce the cost of construction. The assembly of the basic elements together is obtained in a current and nonlimiting manner by flanges, glued plugs, pins, screws or complementary glued interlocking forms. The publication FR-A-2 572 759 describes a beam obtained by the assembly of four parallel squares connected to each other by crosspieces arranged in a chevron. The assembly is carried out by interlocking and gluing of complementary grooves machined respectively in the squares and the sleepers. The aim sought by this invention is to produce long rigid beams. It is also in this purpose that the squares are prestressed before their assembly and gluing or that the network of squares is doubled. The publication GB-A-1 603 357 describes a beam of the same construction but in which the crosspieces and the squares are assembled by gluing plywood spacers interposed between them and making it possible to stiffen the assembly.

A major drawback of this type of assembly is that these different fastening systems create rigid connections between the basic elements constituting the wooden beam, and do not allow any freedom of movement between these basic elements. The beam obtained no longer has any elasticity. Consequently, when it is subjected to stresses, these rigid connections generate very significant stresses in the assembly zones which weaken the basic elements concerned which can cause them to crack, or even break. Therefore this technique does not allow the realization of wooden beams of great span. Indeed, the bending due to the load applied to these wooden beams, generates excessive forces in the assembly areas, and leads to the rupture of the wooden beams. The production of large-span wooden beams of this type therefore necessarily requires the use of at least one intermediate load-bearing wall making it possible to reduce the stresses undergone by these wooden beams.

The present invention aims to overcome these drawbacks by proposing a method of manufacturing a simple, economical, ecological wooden beam, without machining or prestressing, making it possible to keep the beam its flexibility, in particular in its assembly zones, for distributing uniformly the stresses throughout the beam, thus increasing the resistance of the frames obtained by the assembly of these beams, and being able to produce wooden beams of great span without requiring an intermediate bearing wall. The invention also aims to propose a wooden beam having a good squareness and making it possible to ensure good bracing as well as good mechanical strength, in particular in the event of earthquakes, thanks to the flexibility of its assembly zones.

Finally, the invention aims to propose a wooden frame for the construction of a building making it possible to improve the comfort of the habitat by eliminating the squeaks and the cracking noises of the wood, by limiting the cracks, and by increasing the flexibility of the floor, thanks to the flexibility of its assembly areas.

To this end, the invention relates to a manufacturing method as defined in the preamble characterized in that it comprises the steps of laying a first plaice and a second plaice parallel and at a predetermined distance, of laying at least two rectilinear crosspieces on the first two squares and bonding their contact areas by means of a so-called flexible adhesive, laying on said crosspieces with a third square and a fourth square respectively opposite the first square and the second square and bonding their areas of contact by means of a so-called flexible glue, and of tightening the assembly thus obtained to crush the layers of glue to a predetermined thickness, these layers of glue being arranged to form, after crushing and drying, elastic seals in each assembly zone of said beam allowing relative movement between the squares and the corresponding crosspieces.

According to an advantageous characteristic of lïnvention, the so-called flexible glue used is marketed under the brand ADHEFLEX ^® Tl.

According to another advantageous characteristic of the invention, a retaining rod is placed in the assembly zone. According to another advantageous characteristic of the invention, the squares and the crosspieces have an identical section.

According to another advantageous characteristic of the invention, the crosspieces are positioned at regular intervals and according to a predetermined pattern, to form with respect to the squares an angle a different from 90 °, for example between 20 and 40 °, and preferably equal to 30 °.

According to another advantageous characteristic, the crosspieces are positioned in a chevron.

The invention also relates to a wooden beam consisting of basic elements defining its edges and forming at least four squares connected by other basic elements forming at least two crosspieces, characterized in that the squares and the crosspieces are assembled in zones assembly by bonding their contact areas according to the manufacturing process as defined above.

In this embodiment, the adhesive used is a flexible adhesive arranged to form after drying elastic seals allowing relative movement of the squares relative to the crosspieces and vice versa. The squares and crosspieces can have a section chosen from the group containing at least one square, one rectangle.

According to an advantageous characteristic of the invention, at least one of the assembly zones is at least partially crossed by a retaining rod.

The invention also relates to a wooden frame for the construction of a building, characterized in that it consists of wooden beams as defined above, assembled to form a frame section comprising including poles, ties and crossbowmen. Several slices of framework can be arranged to form a modular framework.

According to an advantageous characteristic of the invention, the wooden frame comprises wooden beams assembled by means of at least one connecting element chosen from the group comprising at least one gusset, a cable, a screwed or studded plate, a spacer in recesses.

In another embodiment, the wooden frame comprises wooden beams arranged to receive technical sheaths, and / or supports for roller shutter boxes, mosquito nets and solar panels.

The present invention and its advantages will appear more clearly in the following description of an exemplary embodiment, with reference to the appended drawings, in which:

FIG. 1 is a perspective view of a wooden beam according to the invention,

FIG. 2 is an exploded perspective view of part of a wooden frame made with wooden beams from FIG. 1, and

FIG. 3 is a partial overall view in perspective of the wooden frame according to FIG. 2.

Referring to Figure 1, the wooden beam 1 has a section s Part of a rectangle and has basic elements defining its edges and forming four squares 2a, 2b, 2c, 2d, connected by basic elements forming crosspieces 3a, 3b arranged in chevrons. The basic elements are assembled in assembly zones 5, by bonding their contact zones 4. The squares 2a, 2b, 2c, 2d and the crosspieces 3a, 3b are basic elements made of straight wood. So that they can be cut easily and in a standardized manner, these basic elements preferably have an identical section, for example square or rectangular. A nonlimiting example of dimensions of a rectangular section of basic elements is 70 mm by 30 mm. This standardization of cuts makes it possible to simplify production and increase the efficiency of cutting machines. These basic elements can be used directly as raw parts from the sawmill or, if necessary, after planing to adjust their section. They do not require any particular machining, nor any prestressing. The length of the squares 2a, 2b, 2c, 2d is chosen according to the length of the beam to be manufactured. Similarly, the length of the crosspieces 3a, 3b which serve inter alia as spacers between the squares 2a, 2b, 2c, 2d, is chosen according to the width of the beam to be manufactured.

In order to limit the risk of cracks, or even to totally eliminate them, all the basic elements are cut from the wood, in an area that does not pass through the heart of the trunk or tree branch. In addition, these basic elements have a relatively small section allowing their treatment at heart with fungicides and insecticides which assure them to be class 2 and to have a very long life.

The squares 2a, 2b, 2c, 2d and the crosspieces 3a, 3b are assembled by gluing their contact zones 4. Gluing is carried out advantageously by means of a so-called flexible glue. It is in fact a glue which has the advantage after drying, of remaining flexible and of forming an elastic joint allowing relative movements of the basic elements between them and consequently retaining the flexibility of the wooden beam. A nonlimiting example of so-called flexible glue is known under the trade name dΑDHEFLEX ^® Tl and comprises in particular the monocomponent polyurethane. Of course, other adhesives may be suitable, provided that they have this essential characteristic of flexibility. The use of so-called flexible adhesive makes it possible to better distribute the stresses in the assembly zones and therefore to increase the mechanical strength of these assembly zones. The flexibility of the wooden beam is improved which gives it better resistance to mechanical stress, especially during earthquakes. When the beam, and in particular a very long beam, is subjected to significant bending forces, it undergoes deformation by elasticity. The tensile and compressive forces are distributed in the wood fibers which can deform thanks to their own elasticity and thanks to the elasticity of the glue joints. As a result, this beam can achieve mechanical performance far superior to traditional solid beams, allowing it spans of more than 8 meters.

The beam 1 may also include in its assembly zones 5 retaining rods which may be through and whose function will be explained in the description of the manufacturing process.

It is obvious that the number of crosspieces will be adapted in particular as a function of the length of the desired wooden beam 1 and of the envisaged load. Similarly, the installation angle α defined between the squares 2a, 2b, 2c, 2d, and the crosspieces 3a, 3b can be adapted. In general, increasing this laying angle α allows a reduction in the number of crosspieces and therefore the cost of the wooden beam 1. The choice of laying angle α is therefore a compromise to be found between the cost of the wooden beam 1 and its desired performance. Generally, the installation angle α can be between 20 and 40 °. An installation angle α equal to 30 ° seems to be, for example, an optimal compromise.

This wooden beam 1 is manufactured according to a specific manufacturing process comprising the following different stages.

Firstly, two basic elements are formed in a template, parallel and in the same direction, forming two squares 2a, 2c. The distance between the faces most distant opposite of these squares 2a, 2c will determine the width of the wooden beam 1.

In a second step, the basic elements forming the crosspieces 3a, 3b are placed and glued using the so-called flexible glue defined above on the first two squares 2a, 2c, according to a predetermined pattern, for example in rafter at a predefirii installation angle α. The crosspieces 3a, 3b are placed so that their ends do not protrude from said squares 2a, 2c, towards the outside of said beam 1.

The arrangement of the basic herringbone elements automatically ensures the bracing of the wooden beam 1. In addition, the squareness of the wooden beam 1 is guaranteed and thereby gives the wooden beam 1 good stability dimensional over time.

In a third step, two other basic elements forming a third square 2b and a fourth square 2d, respectively, are placed and glued on the crosspieces 3a, 3b, using the so-called flexible glue defined above. of the first plaice 2a and the second plaice 2c.

In a fourth step, the wooden beam 1 thus formed is placed in a press advantageously equipped with pneumatic cylinders. The press is actuated which tightens the structure, or in a more targeted manner, the assembly zones 5 comprising the contact zones 4. The layers of adhesive are crushed to a predetermined thickness forming, after drying, elastic joints. thickness of these elastic joints being determined as a function of the thickness e of the wooden beam 1 and of its specifications. For example, for a wooden beam 1 with a span of 8 m, the elastic joints have an optimal value of 0.6 to 0.7 mm. In a fifth and final step, a nail or any other retaining rod is planted in each of the assembly zones 5 so as to secure the corresponding basic elements. This nail fulfills only a function of clamp allowing to move the wooden beam 1 and to release the press without waiting for the end of the setting time of the glue. By limiting this waiting time, this increases the speed of production and therefore the profitability of the manufacturing process.

This type of process is simple, fast, economical and ecological. It allows the manufacture of wooden beams 1 in one piece of very varied dimensions ranging from a small gable beam to a load-bearing wooden beam known as having a large span, of length up to, for example, 8 m. The wooden beams 1 thus manufactured are of a reduced weight therefore easier to handle than the one-piece wooden beams or in glued lamellae.

By using a similar manufacturing process using the same press and the same basic wooden elements, it is possible for particular applications such as for the underside of the roof to produce wooden beams 1 comprising crosspieces positioned perpendicular to the squares 2a, 2b, 2c, 2d.

The use of the wooden beam 1 manufactured according to this process is described with reference to Figures 2 and 3.

Figure 2 illustrates an example of assembly of four wooden beams 1, numbered according to Figure 1: la, lb, le, ld. In this example, the wooden beams la, lb, le, ld are used to form a post lia, a beam 11b and a crossbowman lie, lld. The entry 11b is formed by the wooden beam 1b and by another wooden beam not shown, the two horizontal wooden beams and assembled end to end by means of a gusset 6a. Thanks to the use of the so-called flexible glue giving better resistance to wooden beams 1, the entry 11b can be of great range without requiring the use of an intermediate load-bearing wall. The crossbowman binds is formed by the two wooden beams le, ld, assembled end to end by the horizontal spacer 7 fitting into recesses 8 provided in the ends of the two beams le and ld. To allow the junction of the entry 11b, the post 11a and the crossbowman linked, the ends of the wooden beams 1a, 1b, have zones without crosspiece allowing the passage of a gusset 6b. The assemblies of wooden beams (la, lb, le, ld) obtained in FIG. 2 by means of the gussets 6a, 6b and the spacer 7, can also be obtained by means of other elements such as in particular cables, screwed or studded plates.

Figure 3 gives an example of a wooden frame 10 made with the wooden beams 1 assembled according to Figure 2 to form ties 11b, poles 11a and crossbowmen lie. This example clearly shows how the ties 11b, poles 11a and crossbowmen lie can be arranged to form "slices" of frame 9 and allow modular assembly of an entire structure forming the wooden frame 10 of a building, without an interior bearing wall. Indeed, the framing sections 9 can be placed one next to the other to construct buildings of varying lengths as desired.

The so-called flexible glue gives good flexibility to these wooden frames 10, making it possible to suppress the creaking and cracking noises of the wood, to increase the flexibility of the floor, and more generally to improve the comfort of 1 habitat while limiting the risk of cracks.

The wooden beams 1 constituting the wooden frames 10 define intervals advantageously used to receive technical sheaths allowing the passage of electric cables or any type of conduits. The technical sheaths thus housed in the wooden frame 10 no longer pose a problem of aesthetics and / or size. The wooden beams 1 can also be arranged for receive without limitation supports for the installation of roller shutter boxes, mosquito nets and solar panels.

The present invention is not limited to the example of embodiment described but extends to any modification and variant obvious to a person skilled in the art while remaining within the scope of the protection defined in the appended claims.

Claims

claims

1. Method for manufacturing a wooden beam (1) consisting of basic elements defining its edges and forming at least four squares (2a, 2b, 2c, 2d) connected by other basic elements forming at least two crosspieces ( 3a, 3b), the squares (2a, 2b, 2c, 2d) and the crosspieces (3a, 3b) being assembled in assembly zones (5) ^" , by bonding their contact zones (4), characterized in that the method comprises at least the following steps:

- first and second squares (2a, 2c) are laid in parallel and at a predetermined distance,

- at least two crosspieces (3a, 3b) are placed on the two squares (2a, 2c), and their contact areas (4) are glued using a so-called flexible glue,

- a third square (2b) and a fourth square (2d) are placed respectively opposite the first square (2a) and the second square (2c) on said crosspieces (3a, 3b), and their contact areas are bonded (4 ) using a so-called flexible glue,

- This assembly is pressed to crush the layers of glue to a predetermined thickness, these layers of glue being arranged to form after crushing and drying of the elastic joints in each zone of assembly of said beam allowing relative movement between the squares and the crosspieces correspondents.

2. Method according to claim 1, characterized in that one uses the so-called flexible glue marketed as the trademark of ADHEFLEX ^® Tl.

3. Method according to claim 1, characterized in that there is placed in at least one assembly zone (5) at least one retaining rod.

4. Method according to claim 1, characterized in that squares (2a, 2b, 2c, 2d) and crosspieces (3a, 3b) of identical section are used.

5. Method according to claim 1, characterized in that the crosspieces (3a, 3b) are positioned at regular intervals and according to a predetermined pattern.

6. Method according to claim 5, characterized in that the crosspieces (3a, 3b) are positioned relative to the squares (2a, 2b, 2c, 2d) according to a laying angle α different from 90 °.

7. Method according to claim 6, characterized in that the laying angle α is chosen between 20 and 40 ° and preferably equal to 30 °.

8. Method according to claim 6, characterized in that the crosspieces (3a, 3b) are positioned in a chevron.

9. Wooden beam (1) consisting of basic elements defining its edges and forming at least four squares (2a, 2b, 2c, 2d) connected by other basic elements forming at least two crosspieces (3a, 3b) , characterized in that the squares (2a, 2b, 2c, 2d) and the crosspieces (3a, 3b) are assembled into assembly zones (5) by bonding their contact zones (4) according to the defined process according to claim 1.

10. Wooden beam (1) according to claim 9, characterized in that the adhesive used is a so-called flexible adhesive arranged to form, after drying, elastic seals allowing relative movement of said squares (2a, 2b, 2c, 2d) with respect to to the said sleepers (3a, 3b) and vice versa.

11. Wooden beam (1) according to claim 9, characterized in that said squares (2a, 2b, 2c, 2d) and said crosspieces (3a, 3b) have a section chosen from the group containing at least one square, one rectangle.

12. Wooden beam (1) according to claim 9, characterized in that at least one of the assembly zones (5) is at least partially crossed by a retaining rod.

13. Timber frame (10) for the construction of a building, characterized in that it consists of wooden beams (1) according to claim 9, assembled to form at least one frame edge (9) comprising at minus a post (lia), an entry (11b), a crossbowman (lie).

14. Timber frame (10) according to claim 13, characterized in that the frame edge (9) comprises at least two wooden beams (1) assembled by means of at least one connecting element.

15. Timber frame (10) according to claim 14, characterized in that said assembly element is chosen from the group comprising at least one gusset (6a, 6b), a cable, a screwed or studded plate, a spacer (7 ).

16. Timber frame (10) according to claim 13, characterized in that said frame sections (9) are arranged to form a modular wooden frame.

17. Timber frame (10) according to claim 13, characterized in that said wooden beams (1) are arranged to receive technical sheaths, and / or supports for roller shutter boxes, mosquito nets, and solar panels.