Blade abutting method and siding assembly

The method of aligning board ends within a groove and joining piece on a support board simplifies and reduces the cost of cladding installation by transferring forces to the support board and joists, addressing the structural instability of traditional cladding methods.

EP4764114A1Pending Publication Date: 2026-06-24WOODESIGN

Patent Information

Authority / Receiving Office
EP · EP
Patent Type
Applications
Current Assignee / Owner
WOODESIGN
Filing Date
2025-12-23
Publication Date
2026-06-24

AI Technical Summary

Technical Problem

Existing cladding installations on joists are time-consuming and expensive due to the need for additional structural reinforcement at board ends, which can break or sag under weight, and require additional joists under the joint for stability.

Method used

A method using a support board with grooves and a joining piece that aligns and secures the ends of two boards within a single groove, transferring forces to the support board and joists for structural stability without additional joists.

Benefits of technology

This method simplifies installation, reduces costs, and provides structural stability by eliminating the need for additional joists, while maintaining mechanical robustness comparable to traditional methods.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a method for joining boards using: • two joists; • a support board (1) having at least one lower lip (111); • two boards to be joined (2) each having at least one lower lip; and • a joining piece (5) comprising two grooves; the joining method comprising the steps of: • fixing a groove of the joining piece (5) on the lower lip of the support board (1), the joining piece (5) being disposed between the joists; • inserting the lower lips of the boards to be joined (2, 3) into the groove of the joining piece (5), the joining piece (5) thus being supported only by the support board (1) and the boards to be joined (2, 3).
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Description

TECHNICAL FIELD

[0001] The present invention relates to the joining of blades, in natural or composite material, to form a cladding or decking, such as a covering, a siding, a facing or a terrace, on a support structure which may include joists or profiles. STATE OF THE ART

[0002] In the field of cladding, and more specifically terraces, there are many solutions to allow the alignment and holding in position of the boards against profiles or joists.

[0003] Cladding installation on joists is generally carried out from one end of the surface to be covered to the other. The joists are laid across the surface, parallel to each other. Several boards are then fixed to these joists, oriented perpendicular to them.

[0004] A common problem arises when two boards are butted together. Butting refers to the contact between the ends of the two boards, also known as "ends." Without adequate structural reinforcement, the ends can break or sag, especially under the weight of an object placed on the end of the board. The problem also occurs when people's heels or chair legs regularly press against these ends. To provide structural strength, it is common practice to use an additional joist placed under the joint between the butted ends. In this way, the ends, resting on the additional joist, are not at risk of collapsing. It is also common to arrange the board ends and / or joists so that there is a joist under each board, in the immediate vicinity of the ends.Each end is thus properly supported by one of the joists. The cladding thus formed is robust, particularly at the points where the boards meet.

[0005] In practice, installing cladding, a terrace or robust facings with its joists and boards proves to be relatively long and expensive.

[0006] Therefore, there is a need to eliminate or mitigate these drawbacks. In particular, there is a need to make the installation of the cladding faster and less expensive. SUMMARY

[0007] To achieve this objective, the invention provides a method for joining blades using: a first joist and a second joist adjacent to each other; a support board having an edge, said edge having at least one lower lip and preferably having a groove separating, at least in part, the edge into a lower lip and an upper lip; a first board to be butted and a second board to be butted, the two boards to be butted each having an end and at least one first edge, said first edge of each board to be butted having at least one lower lip and preferably a groove separating, at least in the vicinity of the end, the first edge into a lower lip and an upper lip;and a joining piece comprising a first groove and a second groove and preferably a top member, the two grooves being arranged back to back, the top member preferably forming a wall of the first groove and a wall of the second groove, the top member being preferably configured to cooperate with the groove of the support blade if necessary, the first groove being configured to cooperate with the lower lip of the support blade, the top member being preferably configured to cooperate with each of the grooves of the first and second blades to be joined if necessary and the second groove being configured to cooperate with each of the lower lips of the first edges of the first and second blades to be joined. ;

[0008] The end-jointing process includes the following steps: fix the support board to the first and second joists; fix the joining piece to the support board by inserting the first groove of the joining piece onto the lower lip of the support board and preferably inserting the upper flange of the joining piece into the groove of the support board if necessary, the joining piece being positioned between the first joist and the second joist; fix the first end-to-end board to the joining piece by inserting the lower lip of the first edge of the first end-to-end board into the second groove of the joining piece and preferably inserting the upper flange of the joining piece into the groove of the first end-to-end board if necessary, leaving a portion of the second groove of the joining piece free, the first end-to-end board resting on the first joist;fix the second end-joint to the joining piece by inserting the lower lip of the first edge of the second end-joint into the free portion of the second groove of the joining piece and preferably inserting the upper flange of the joining piece into the groove of the second end-joint if necessary, the second end-joint resting on the second joist; the joining piece is supported only by the support board and the first and second end-joints.

[0009] The two blades to be joined are both inserted into the same groove in the joining piece. Their lower edges are aligned with each other, both vertically and laterally, resulting in good alignment of the blades. If the joining piece has a top flange, this flange extends from the groove of the first blade to the groove of the second blade. Their grooves are thus also aligned with each other, both vertically and laterally, resulting in improved alignment of the blades. The ends of the blades face each other, ensuring a proper butt joint. Because the lower edges are in the same groove, the ends of the two blades can be placed in contact or left slightly apart.

[0010] A force applied at the joint between the ends of the two boards is transferred at least to the second groove of the joining piece and preferably to the top flange of the joining piece. This force is then transmitted to the support board, and in particular to its lower lip. This transferred force is in turn transferred to the joists to which the support board is fixed. The support board thus prevents the ends of the boards from collapsing. The installation of the joining piece, as well as the arrangement of the boards, provides structural stability to the entire assembly.

[0011] Therefore, it is not necessary to place one or more joists under the joint between the ends of the two boards or in the immediate vicinity of these ends. This simplifies the installation of the boards on the joists while providing sufficient structural strength. Furthermore, the time required to complete the cladding is considerably reduced. Its cost is also reduced since the supply and installation of joining joists under the ends is eliminated.

[0012] The invention also relates to a clothing assembly, which can be obtained using the process according to the invention, comprising: a first joist and a second joist close to each other; a support board, having an edge having at least a lower lip and preferably a groove separating, at least in part, the edge into a lower lip and an upper lip; a first board to be butted and a second board to be butted, the two boards to be butted each having an end and a first edge, said first edge of each board to be butted having at least a lower lip and preferably a groove separating, at least in the vicinity of the end, the first edge into a lower lip and an upper lip;and a joining piece comprising a first groove, a second groove and preferably a top member, the two grooves being arranged back to back, the top member preferably forming a wall of the first groove and a wall of the second groove, the member being preferably configured to cooperate with the groove of the support blade if necessary, the first groove being configured to cooperate with the lower lip of the support blade and the second groove being configured to cooperate with each of the lower lips of the first edges of the first and second blades to be joined.

[0013] In particular, the support board is fixed to the first and second joists, the joining piece is fixed to the support board, the upper flange of the joining piece being preferably inserted into the groove of the support board if necessary, the first groove of the joining piece being inserted into the lower lip of the support board, the joining piece being positioned between the first and second joists, the first board to be joined being fixed to the joining piece, the upper flange of the joining piece being preferably inserted into the groove of the first board to be joined, the lower lip of the first edge of the first board to be joined being inserted into a first part of the second groove of the joining piece, the first board resting on the first joist, the second board to be joined being fixed to the joining piece,The upper member of the joining piece is preferably inserted into the groove of the second board to be joined, the lower lip of the first edge of the second board to be joined is inserted into a second part of the second groove of the joining piece, the second board resting on the second joist, the joining piece is supported only by the support board and the first and second boards to be joined. BRIEF DESCRIPTION OF THE FIGURES

[0014] The aims, objects, features and advantages of the invention will become clearer from the detailed description of an embodiment thereof, which is illustrated by the following accompanying drawings in which: There figure 1 represents an example of a step in a butt-jointing process according to the invention. figures 2a , 2brepresent an example, in perspective and cross-section, of a connecting piece such as can be implemented in the step of the figure 1 . THE figures 3, 4a And 4b schematically represent an example, in perspective and section, of a support blade, a first blade to be butted together, and a joining piece such as can be implemented in the step of the figure 1 . There figure 5 represents a first embodiment of a cladding assembly according to the invention, obtainable by means of the butt-jointing process according to the invention. This figure also represents a complementary step of the butt-jointing process that can lead to the second embodiment of the assembly illustrated by the figure 5 . There figure 6 represents a second embodiment of an assembly according to the invention. The figure 7 represents an example of the implementation of a butt-jointing process according to the invention. figures 8 and 9represent another example, either in isolation or in use with blades, of a connecting piece such as can be implemented in the invention. Figure 10 schematically represents, according to a pair, a further example of a connecting piece such as can be implemented in the invention.

[0015] The drawings are provided as examples and are not intended to limit the scope of the invention. They are schematic representations of the principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. In particular, figures 1 through 6 are not representative of reality. DETAILED DESCRIPTION

[0016] Before beginning a detailed review of embodiments of the invention, optional features which may be used in association or alternatively are stated below: The joining piece, including in particular first and second grooves arranged back to back and configured to cooperate with the lip of the support blade on the one hand and each of the lips of the first and second blades to be joined on the other hand, may be replaced by any joining piece configured to transfer a mechanical force applied at the end of the first blade to be joined and / or at the end of the second blade to be joined, onto the lip of the support blade.

[0017] Advantageously, the first and second blades to be joined 2, 3 each have a second edge 24, 34, said second edge of each blade to be joined having a lower lip 241, 341 and preferably a groove 240, 340 separating, at least in the vicinity of the end 21, 31, the second edge into at least a lower lip 241, 341 and an upper lip 242, 342.

[0018] Advantageously, the butt jointing process includes reinforcing the butt joint using: an additional support blade 1 having a bevel 12, said bevel having a lower lip and preferably a groove separating, at least in part, the bevel into a lower lip and an upper lip;an additional joining piece 5 comprising a first groove 51, a second groove 52 and preferably an upper member 53, the two grooves being arranged back to back, the upper member forming a wall of the first groove and a wall of the second groove, the upper member being preferably configured to cooperate with each of the grooves of the second edges of the first and second blades to be joined, the first groove being configured to cooperate with each of the lower lips of the second edges of the blades to be joined, the upper member being preferably configured to cooperate with the groove of the additional support blade, the second groove being configured to cooperate with the lower lip of the additional support blade. ;

[0019] Advantageously, the reinforcement of the butt joint comprises the following steps: fix the additional joining piece on the first and second boards to be joined by inserting the first groove of the additional joining piece on the lower lip of the second edge of the first board to be joined and on the lower lip of the second edge of the second board to be joined and by preferably inserting the upper flange of the additional joining piece into the groove of the second edge of the first board to be joined and into the groove of the second edge of the second board to be joined, the additional joining piece being placed between the first joist 41 and the second joist 42; fix 96 the additional support board on the additional joining piece by inserting the lower lip of the additional support board into the second groove of the additional joining piece and by preferably inserting the upper flange of the additional joining piece into the groove of the additional support board;fix the additional support blade 97 onto the first and second joists; the additional joining piece being supported only by the additional support blade and the first and second blades to be joined.

[0020] Advantageously, the insertion of the first groove 51 of the connecting piece 5 onto the lower lip 111 of the support blade 1 and preferably the insertion of the upper member 53 of the connecting piece 5 into the groove 110 of the support blade 1, are carried out by a movement of the connecting piece oriented perpendicular to the edge 11 of the support blade.

[0021] Advantageously, the insertion of the lower lip 231 of the first edge 23 of the first butted blade 2 into the second groove 51 of the joining piece 5, and preferably the insertion of the upper member 53 of the joining piece 5 into the groove 230 of the first butted blade 2, are achieved by a displacement of the first butted blade oriented perpendicular to the edge 11 of the support blade.

[0022] Advantageously, the fit between the first groove 51 of the connecting piece 5 and the lower lip 111 of the support blade 1 is configured so that the first groove of the connecting piece and the lower lip of the support blade cooperate by clamping, said fit being preferably chosen to allow insertion of the lower lip of the support blade into the first groove of the connecting piece by hand or by means of a mallet operated by a user.

[0023] Advantageously, the adjustment between: the second groove 52 of the joining piece 5 and the lower lip 231 of the first edge 23 of the first blade to be butted 2; and the second groove 52 of the joining piece and the lower lip 331 of the first edge 33 of the second blade to be butted 3; is configured so that: the second groove of the joining piece and the lower lip of the first edge of the first blade to be joined cooperate by clamping; and the second groove of the joining piece and the lower lip of the first edge of the second blade to be joined cooperate by clamping; said adjustment being preferably chosen to allow insertion of the lower lips of the first edges of the first and second blades to be butted into the second groove of the joining piece by hand or by means of a mallet manipulated by a user.

[0024] Advantageously, the joining piece 5 includes a core 54 separating the two grooves 51, 52, said core forming a spacer between the lower lip 111 of the support blade 1 and the lower lips 231, 331 of the first edges 23, 33 of the first and second blades to be butted 2, 3.

[0025] Advantageously, the first and second grooves 51, 52 of the joining piece 5 include teeth 55 configured to bite into the lower lip 111 of the support blade 1 and the lower lips 231, 331 of the first edges 23, 33 of the first and second butting blades 2, 3.

[0026] Advantageously, each tooth 55 forms an edge or point extending mainly in a direction perpendicular to the main direction of extension of the core 54 of the connecting piece 5.

[0027] Advantageously, the second groove 52 of the joining piece 5 includes a first protrusion 58 suitable for forming a spacer between the ends 21, 32 of the first and second blades to be butted 2, 3, said first protrusion separating the second groove into two portions.

[0028] Advantageously, the joining piece 5 includes a second protrusion 57 suitable for forming a spacer between the ends 21, 32 of the first and second butted blades 2, 3, said second protrusion being disposed on the upper member 53 of the joining piece.

[0029] Advantageously, the joining piece 5 includes a lower member 56, extending parallel to the upper member 53 of the joining piece 5, the lower member of the joining piece forming another wall of the first groove 51 and another wall of the second groove 52, the lower member having a width L56 strictly greater than a width L53 of the upper member.

[0030] Advantageously, the support blade 1, the first blade to be butted 2 and the second blade to be butted 3 have sections, considered perpendicular to a principal extension direction of the blades, which is identical, the support blade, the first blade to be butted and the second blade to be butted being preferably identical.

[0031] The terms "cladding" or "decking" extend to any element forming a facing, a covering, a siding, preferably horizontal, such as a terrace.

[0032] The term "joist" refers to any element capable of acting as a structural support for cladding. This includes, for example, joists themselves, as well as profiles and battens.

[0033] The term "neighboring joists" refers to two joists placed side by side and closest to each other. In other words, no other joist is placed between the two neighboring joists.

[0034] The term "blade" refers to any element intended to form a cladding. This includes, for example, slats or planks.

[0035] The terms "flat," "end," and "edge" of a blade refer to different surfaces of the blade that a person skilled in the art can interpret. A flat, for example, is one of the larger surfaces of the blade. The flat is visible, for instance, when the blade is installed. An end, for example, is one of the smaller surfaces. It is located, for example, at one of the blade's extremities. An edge, for example, is a narrow, long surface of the blade, extending, for example, from one end to the other. It may also be called the "side."

[0036] The term "lip" refers to a projection extending from the edge of a blade. The lip may be continuous or discontinuous, for example formed of bumps or protuberances aligned parallel to the main direction in which the blade extends.

[0037] The term "member" or "tongue" refers to a planar element.

[0038] The term "lip extending to the vicinity of the tip" means that the lip can extend along the edge of the song until it reaches the tip, or extend along the edge but stop some distance from the tip. This distance can be interpreted by reading the detailed description.

[0039] A "groove" or "trench" is understood to be a long, open cavity or recess. A groove or groove generally has an opening through which a lip can be inserted.

[0040] By "grooves arranged back to back" is meant that the grooves are oriented so that the bottoms of the two openings are close to each other, while the openings of the grooves are far apart.

[0041] The terms "lip inserted into groove" or "member inserted into groove" and "groove inserted on member" or "groove inserted on lip" refer to the same operation of driving the lip or member into the groove or groove.

[0042] One embodiment of the butt-jointing process 9 will now be described with reference to figures 1 to 7 This process makes it possible to produce an assembly according to the invention, two examples of which are represented by the Figures 5 And 6 The end-jointing process aims to reduce the constraint on the placement of joists to manufacture cladding from planks, while offering mechanical robustness close to, or even equal to, that of cladding according to the prior art.

[0043] There figure 1This represents a perspective view of an example step in the end-jointing process 9. It also shows various elements implemented by this process. Once assembled, the elements form a cladding (the final assembly, which could be a terrace, will simply be referred to as "cladding").

[0044] As depicted in the figure 1 and partially in the figures 3, 4a And 4b The set of elements implemented includes: first and second joists 41, 42; a first support blade 1; a first butt blade 2; a second butt blade 3; and a first joining piece 5.

[0045] The first support blade 1 is intended to provide mechanical strength to the blades to be joined end-to-end. The first support blade 1 has two flats 13, 14 opposed to each other and constituting the largest faces of the support blade 1. One of the flats 13 is, for example, intended to be mounted on the joists 41, 42, or fixed opposite the joists 41, 42, while the other of the flats 14 is, for example, intended to be visible once the cladding is assembled.

[0046] The first support blade 1 has at least one edge 11 and, in practice, two edges 11 and 12 opposite each other. The edges 11 and 12 correspond, for example, to the long sides of the support blade 1. The first edge 11 has at least one groove 110, dividing said edge 11 into two lips 111 and 121, respectively lower and upper. The groove 110 may extend along the entire length of the edge 11 or only over a portion of the edge, for example, where the joining piece 5 is to be fixed.

[0047] The first and second butted boards 2, 3 also each have two flats 25, 26, 35, 36 which also form the large faces of the butted boards 2, 3. The first flats 25, 35 of the butted boards 2, 3 are intended to be mounted on the joists 41, 42, or fixed opposite the joists 41, 42. The second flats 26, 36, for example, are intended to be the visible faces, once the cladding has been assembled.

[0048] Each of the end-jointed blades 2, 3 includes at least one first edge 23, 33 formed by one of the long sides of each blade 2, 3. In practice, each end-jointed blade 2, 3 includes two edges 23, 24, 33, 34. The two edges 23, 24, 33, 34 of the same blade 2, 3 form, for example, the opposite long sides. To distinguish the first edges 23, 33 of the end-jointed blades 2, 3, these are the edges that align when the blades 2, 3 are joined end-jointed.

[0049] Each of the butted blades 2, 3 also has at least one end 21, 31 formed by one of the short sides of each blade 2, 3 and in practice, two ends generally arranged at the ends of the butted blades 2, 3.

[0050] The first edges 23, 33, similar to the first support blade 1, have grooves 230, 330. Each groove 230, 330 separates the first edges 23, 33 into two lips 231, 232, 331, 332, forming lower and upper lips respectively. The grooves 230, 330 can extend along the entire length of the corresponding edges 23, 33 (that is, from one end of the blade to the other). However, they can also be located near the end 21, 31 to be joined. They can extend over a distance, measured from the end 21, 31 to be joined, of between 5 cm and 15 cm, and preferably greater than 5 cm or 15 cm. Ideally, this distance is greater than or equal to half the length of the joining piece 5.

[0051] In the illustrated embodiment (and particularly visible on the figures 3 And 4), each lower lip 231, 331 extends along the first edge until it reaches the end 21, 31 of the blade. Alternatively, each lower lip 231, 331 can extend along the first edge of the blades to be joined 2, 3, stopping at a distance from the ends 21, 31.

[0052] It is advantageous for the first support board 1 and the end boards 2 and 3 to be identical. Thus, each of the boards 1, 2, and 3 can act as either a support board or an end board. Since cladding construction generally involves arranging boards side by side, staggering the end joints, an end board can also serve as a support board for other end boards.

[0053] The different blades 1, 2, 3 can be made from natural material (such as wood), plastic material, composite material (such as a mixture of plastic with natural or synthetic fibers), or metal (for example, aluminum), or even cement.

[0054] An embodiment of the first connecting piece 5, as used in the Figures 1 , 3 , 4a , 4b , 5 And 6 , is illustrated by the figures 2a And 2bThe first connecting piece 5 is a single-piece or monolithic component, that is, made from a single piece. It is preferably made of a single material. In the illustrated embodiments, it has an H shape. It comprises two grooves 51, 52, preferably parallel to each other but arranged back to back. The grooves 51, 52 extend along the entire length of the first connecting piece 5. Furthermore, the grooves 51, 52 open onto the ends of the first connecting piece 5. In other words, they are not blocked, but rather open. Thus, and in the absence of points 55 (described below), it is possible to slide a lip into each groove 51, 52 of the first piece 5. In other words, the first connecting piece 5 has the shape of an H from one end to the other.

[0055] The connecting piece 5 may include a web 54 separating the two grooves 51, 52. The web 54 thus forms the bottom of each groove 51, 52. The first piece 5 also includes lower and upper (also called "top" and "bottom") members 53, 56 forming the sides of the two grooves 51, 52. In other words, the web 54 and the members 53, 56 form the grooves 51, 52. The members 53, 56 and the grooves 51, 52 are configured such that: the first groove 51 is configured to cooperate with the lower lip 111 of the first support blade 1; and the second groove 52 is configured to cooperate with each of the lower lips 231, 331 of the first and second blades to be butted 2, 3.

[0056] Member 53 is configured to cooperate with the groove 110 of the support blade 1 and the grooves 230, 330 of the butting blades 2, 3.

[0057] The first groove 51 is, for example, configured so that the lower lip 111 of the first support blade 1 is inserted by placing the lower lip 111 parallel to the first groove 51, opposite the first groove 51 (for example, oriented parallel to the Y direction in the figure 2a ), and inserted into the first groove 51 along a displacement perpendicular to the first groove 51. This method of inserting the lower lip 111 into the first groove 51 is preferred because it allows the first part 5 to be fixed to a support blade 1 already installed. This insertion must be carried out so that the upper member 53 also enters the groove 110 of the support blade 1. Thus, the upper member 53 can also withstand a mechanical effect applied by the upper lip 112.

[0058] Following the same principle, the second groove 52 can be configured so that the lower lips 231, 331 of the first and second butting blades 2, 3 can be inserted according to the same insertion methods, i.e. by a movement perpendicular to the second groove 52 or by sliding the lower lips 231, 331 into the second groove 52.

[0059] Once inserted into the grooves 51, 52, the lower lips 11, 231, 331 of the blades 1, 2, 3 are positioned between the upper 53 and lower 56 members. The lower member 56 then extends partially onto the lower flat 14, 26 of the blade 1, 2. When a force is exerted on one blade, this force is transferred to the other blade via the connecting piece 5. However, to prevent rotation of the connecting piece 5, which would allow the blades to disengage, the lower member can be configured to be wider than the upper member 53 of the piece 5. In this way, the lower member 56 extends further against the lower flat 14, 26 of the blade 1, 2, thus preventing the rotation of the connecting piece 5. For an upper member 53 with a width L53 of 23 mm, the lower member 56 has for example a width L56 between 25 mm and 30 mm, for example 28 mm.

[0060] In an advantageous embodiment, the lower lips 111, 231, 331 of the first support blade 1 and of the butted blades 2, 3 are identical, for example, in both shape and dimensions. Thus, it is irrelevant which lower lip 111, 231, 331 is presented to one of the grooves 51, 52, since they can all cooperate in the same way with any of the grooves 51, 52. Therefore, the joining piece 5 can be rotated so that the grooves 51, 52 are interchanged without compromising the structural integrity of the installed blades 1, 2, 3. It is also advantageous for the grooves 110, 230, 330 of the different blades to be identical in both shape and dimensions. Thus, the joining piece 5 can be rotated without compromising the structural integrity of the installation.

[0061] In one embodiment, the grooves 51, 52 can cooperate with the lower lips 111, 231, 331 by clamping. In other words, the grooves 51, 52 can have a zero fit relative to the lower lips 111, 231, 331. By "fit," we mean a difference between the dimensions of the grooves 51, 52 and the dimensions of the lips 111, 231, 331. Thanks to the zero fit, the grooves 51, 52 clamp the lips 111, 231, 331, preventing them from slipping. The clamping is preferably dimensioned so that the lips 111, 231, 331 can be inserted by hand, for example by pressing the blade against the joining piece 5. The clamping can also be dimensioned so that the insertion of the lips 111, 231, 331 is carried out by means of a mallet operated by a user.

[0062] Each groove 51, 52 can, for example, have an opening height H51 that is preferably constant along the entire length of the connecting piece 5 and between 8.5 mm and 8.9 mm. The lip 111, 231, 331 to be inserted then has a thickness, measured perpendicular to a principal plane in which the blade 1, 2, 3 extends, that is preferably less than or equal to the opening height H51, for example less than or equal to 8.9 mm, for example equal to 8.5 mm.

[0063] The opening height H51 can be greater than the lip thickness. While this facilitates insertion, it does not provide a secure hold on the lip. The opening width can range from 1% to 110% of the lip thickness. Ideally, the opening height H51 should be equal to the lip thickness. This ensures the lip is tightly gripped in the groove and held firmly in place.

[0064] The two grooves 51, 52 can be adjusted relative to the different lips 111, 231, 331. This allows the joining piece 5 to be attached manually to one of the blades, for example, the support blade 1. An operator can then easily remove and reposition the joining piece 5 on the first support blade 1. The joining piece 5 can be secured to the lips 231, 331 using a mallet to lock them into the joining piece 5.

[0065] The grooves 110, 230, and 330, designed to accommodate the top member 53, may also have a fit with the top member 53 such that a mallet is required to insert one into the other. However, the constraint at the groove may be released to facilitate the insertion of the joining piece 5 onto the blades 1, 2, and 3. For a member with a thickness H53 of 3.5 mm, the grooves 110, 230, and 330 may have a width between 3.5 mm and 5 mm, and preferably between 4 mm and 5 mm.

[0066] In an embodiment independent of or complementary to clamping, one or both of the grooves 51, 52 may include a means for preventing the lips 111, 231, 331 from slipping. This means, for example, consists of teeth 55 extending into the grooves 51, 52. The teeth 55 are, for example, arranged in the bottom of the grooves 51, 52. They extend, for example, from the wall 54 towards the opening of each of the grooves 51, 52. Thus, when one of the lips 111, 231, 331 is inserted into one of the grooves 51, 52, the teeth 55 penetrate said lip. This prevents the lip from slipping in the groove. It is preferable that the teeth 55 have a hardness strictly greater than the hardness of the blades 1, 2, 3.

[0067] The teeth 55 may have a pointed shape, extending perpendicularly to and from the wall 54. They may have an edge shape (as illustrated in the figures 2a And 2b extending from wall 54 and against one of the members 53, 56, or against each member 53, 56 alternately. Whether the teeth 55 are pointed or angled, they extend preferentially in the direction of lip insertion. In this way, they do not prevent insertion but only block sliding in the groove.

[0068] The teeth 55 can contribute to tightening the lips, thus the grooves 51, 52 are simpler to produce since a perfect fit is no longer required. The teeth 55, for example, have a beveled shape extending from the edge of the frame 53, 56 and widening as they approach the web 54. At their widest point, they can have a width H55 equal to one-third of the height of the openings H51, or approximately 3 mm.

[0069] The connecting piece 5 can be made of metal (e.g., aluminum), plastic, or a composite material, for example, polypropylene with glass fibers. For optimal tooth retention, it is preferable that the teeth have a significantly higher hardness than the lips 111, 231, 331. The piece 5, like the teeth 55, is, for example, made of metal or composite, while the blades 1, 2, 3 (and therefore the lips 111, 231, 331) are made of wood, plastic (e.g., PVC), or composite material.

[0070] In the figures 2a , 2b , 3, 4a And 4b The connecting piece 5 has an H-shape. It includes, in particular, a web 54 and two complementary members 53, 56. The web 54 extends, for example, parallel to the Y direction and perpendicular to a plane {X, Y} (an orthogonal coordinate system {X; Y; Z} is represented in the figures 1 to 4The upper and lower members 53, 56 then extend parallel to the Y direction and parallel to the plane {X; Y}, and more specifically, one above the other. The web 54 joins the two members 53, 56 together. In this way, the cross-section (in a plane {X; Z}) of the connecting piece 5 forms an H-shaped section. The members 53, 56 and the web 54 then form the grooves 51, 52 of the piece 5, each of the members 53, 56 forming one side of said groove 51, 52.

[0071] Members 53, 56 may have a soft edge, for example rounded, to guide and facilitate the insertion of lips 111, 231, 331 into grooves 51, 52. These soft edges also facilitate the insertion of the upper member 53 into grooves 110, 230, 330 in blades 1, 2, 3. Members 53, 56 shown in the figures 2a , 2b , 3, 4a And 4b are straight.

[0072] In the Figures 1 , 3 ,4a And 4b The lips 111, 231, 331 of the blades 1, 2, 3 form what are called "lower" lips. The joining piece 5 on one of the blades 1, 2, 3 can be made at the level of these lower lips 111, 231, 331. Each of the first edges 11, 23, 33 advantageously presents an upper lip 112, 232, 332 (which can also be called an "additional lip"). The lower and upper lips 111, 231, 331, 112, 232, 332 result from the formation of a groove 110, 230, 330 in the edges 11, 23, 33. These lips are preferentially parallel to each other.

[0073] For example, edge 11 of the support blade 1 has an upper lip 109, parallel to the lower lip 111. Similarly, edges 23, 33 of the blades to be butted 2, 3 may have upper lips 232, 332, parallel to the lower lips 231, 331.

[0074] In a preferred embodiment, each edge 11, 23, 33 has a lower lip 111, 231, 331 and an upper lip 112, 232, 332. Thus, when the joining piece 5 is inserted onto the blade, its upper member 53 is positioned between these two lips. Consequently, a force applied to a blade 1, 2, 3 can be applied, at least in part, to the upper member 53 via the upper lip 112, 232, 332 of the edge in question. The lower lip, for its part, applies part of the force in the groove 51, 52 (and, for example, onto the lower member 56).

[0075] In an equivalent embodiment, each edge 11, 23, 33 may have only one of the two lips, specifically only the lower lip 111, 231, 331. This lower lip is, for example, formed by an asymmetrical machining of the edge 11, 23, 33. Therefore, inserting the joining piece 5 onto the blade is equivalent to inserting the lower lip 111, 231, 331 into the corresponding groove 51, 52. In the absence of a groove, the upper member 52 then only fits into the upper part of the lower lip. The entire force applied to the blade is then transferred to the lower lip.For soft materials, it is advantageous for the lower lip to have a height H231 representing a substantial part of the height H2 of the edge in which it was machined, for example between 40% and 80% of the height H2 of the edge (in the figures, only the heights H231 and H2 of the lower lip 231 and of the first blade to be butted are shown, however this can apply to all blades.

[0076] When the blades 1, 2, and 3 are attached to the connecting piece 5, the upper lips 11, 232, and 332 partially conceal the connecting piece 5. The upper flange 53 of the piece 5 can be partially or completely concealed by the corresponding upper lip 112, 232, and 332. The cladding is then more aesthetically pleasing since the connecting pieces 5 are more visible. It can also be safer, since the upper lips 107, 232, and 332 also act as a protective barrier, preventing a person walking on the cladding from tripping or dislodging the connecting pieces 5.

[0077] Alternatively, the joining piece 5 can also be attached to the upper lips 112, 232, 332 instead of the lower lips 111, 231, 331. This corresponds to an inverted joining piece 5. The principles described here then apply, considering that the upper lips 112, 232, 332 become the lower lips 111, 231, 331, and vice versa. This can be advantageous for aesthetic cladding, such as vertical panels like open-joint siding, if this type of cladding is not intended for pedestrian traffic.

[0078] In one embodiment, illustrated by the figures 8 and 9The second groove 52 of the joining piece 5 may include a first protrusion 58 dividing the second groove 52 into two portions. The end-jointed blades 2, 3 can then be inserted into each of these portions of the groove 52, separated at least by the first protrusion 58. This protrusion 58 then acts as an end-jointing spacer, providing a means of easily joining the blades without having to measure the distance between the blades 2, 3. This first protrusion 58 is advantageously located only in the second groove 52, or at least in the groove intended to receive the end-jointed blades. The first groove 51, intended to receive the support blade 1, is preferably free, so as not to hinder the insertion of the support blade 1.

[0079] The first protrusion 58 forms a wall within the second groove 52, extending from the web 54 of the part 5 to the edges of the upper and lower members 53, 56. This protrusion 58 allows, for example, the butted blades 2, 3 to be spaced apart by a distance of between 1 mm and 5 mm, and preferably between 2 mm and 4 mm, for example 3 mm. The first protrusion 58 has a thickness, measured parallel to the principal direction in which the second groove 52 extends, of between 1 mm and 5 mm, and preferably between 2 mm and 4 mm, for example 3 mm. The first protrusion 58 is, for example, located in the middle of the second groove 52.

[0080] In a complementary or alternative embodiment, also illustrated by the figures 8 and 9The joining piece 5 includes a second protrusion 57 adapted to form a spacer between the ends 21, 32 of the butted blades 2, 3. Unlike the first protrusion, this second protrusion 57 is not located in the second groove 52 but on the upper member 53 of the piece 5. It is positioned on an edge of the member 53 and only on the portion of the upper member 53 that forms a wall of the second groove 52. In this way, this second protrusion 57 does not hinder the insertion of the support blade 1 while forming a spacer between the butted blades 2, 3. Similar to the first protrusion, the second protrusion 57 has a thickness, measured parallel to the principal direction in which the second groove 52 extends, of between 1 mm and 5 mm, and preferably between 2 mm and 4 mm. example 3 mm.

[0081] The end-jointing of boards 2, 3 consists of placing the ends 21, 31 of two boards to be joined 2, 3 in contact with each other. The end-jointing method 9 according to the invention is remarkable in that it allows for a mechanical connection between the two facing ends 21, 31, providing a solid cladding capable of withstanding a significant weight applied at the ends 21, 31 of the boards to be joined 2, 3. The method has the additional advantage of offering a mechanical connection that does not require the use of an additional joist to reinforce the boards to be joined 2, 3 at the ends 21, 31 and allows for the management of overhangs of the joined boards.

[0082] There figure 7 schematically represents the sequence of steps in the butt-jointing process 9. figure 1 shows one of these steps.

[0083] In a previous, initial step, a number of joists were laid on the surface to be covered. figure 1The diagram shows only two of them. These first and second joists, 41 and 42, are placed side by side and parallel to each other. In particular, they extend parallel to the X direction. The two joists are adjacent to each other; in other words, there is no additional joist placed between them. In this example, joists 41 and 42 are metal profiles.

[0084] In a second stage, also prior to the figure 1The first support board 1 is fixed to two joists 41, 42 and, in this case, at one end of these joists 41, 42. The first support board 1 is, for example, fixed to the joists 41, 42 by means of fasteners 6 as described in patent FR312535 B1 or as described in patent FR3019201 B1. The first support board 1 is fixed to the joists 41, 42 by fasteners 6 that are different from the connecting pieces 5. The fasteners 6 cooperate on the one hand with the edges of the individual boards and on the other hand with the joists 41, 42, which is not the case for the connecting piece 5. The first support board 1 can also be fixed to the joists 41, 42 by screwing.

[0085] The support blade 1 is oriented perpendicular to the two joists 41, 42, that is to say in the Y direction. Alternatively, it can be laid at a different angle to the joists 41, 42, for example 45°.

[0086] In a third stage, prior to the figure 1 The first connecting piece 5 was fixed 91 onto the support board 1 by inserting the first groove 51 of said piece 5 onto the lip 111 of the support board 1. The connecting piece 5 was inserted, for example by hand, by pushing the first groove 51 onto the lower lip 111 of the support board 1. The pressure applied to the first connecting piece 5 is, for example, perpendicular to the edge 11 of the support board 1. The first connecting piece 5 is positioned between the two joists 41, 42, for example equidistant from the two joists 41, 42 or closer to one of the two joists 41, 42.

[0087] The step illustrated by the figure 1This corresponds to the fixing 92 of the first butt-jointed blade 2 onto the joining piece 5. The lower lip 231 of the first butt-jointed blade 2 is inserted into the second groove 52 of the joining piece 5. The lower lip 231 of the first butt-jointed blade 2 is, for example, presented in front of the second groove 52 and pressed against it in a movement perpendicular to the edge 11 of the support blade 1. During this step, the joining piece 5 is oriented so that the upper flange 53 of the joining piece is inserted into the groove 230 of the first butt-jointed blade 2. In the case where the second groove 51 of the joining piece 5 is configured to clamp the lower lip 231 of the first butt-jointed blade 2, the insertion of the lower lip 231 can be made using a mallet. The first end-joint 2 is positioned so that it can be fixed onto the first joist 41.The first end-jointed blade 2 is then fixed to the first joist 41 using a fixing means 6 as described previously, or by screwing.

[0088] The lower lip 231 of the first butted blade 2 is preferentially inserted so as to occupy only a portion, and in particular half, of the second groove 52. The second groove 52 thus presents a free portion into which another lip can be inserted. The upper member 53 is also partially free.

[0089] There figure 5Figure 9 shows a second step of the butting process. It allows a cladding sub-assembly to be formed. In this step, the second butting blade 3 is fixed 93 to the joining piece 5. In particular, the second butting blade 3 is fixed to the joining piece 5 by inserting the free part of the upper member 53 of the joining piece 5 into the groove 330 of the second butting blade 3 and by inserting the lower lip 331 of the second butting blade 3 into the free portion of the second groove 52 of the joining piece 5.

[0090] The lip 331 of the second butted blade 3 is, for example, presented in front of the free portion of the second groove 52. It is then pressed against the latter, following a movement perpendicular to the edge 11 of the support blade 1. The movement is materialized in the figure 5indicated by thick black arrows. If the second groove 51 of the joining piece 5 is configured to clamp the lip of the second butt-jointed board 3, the lip 331 can also be inserted using a mallet. The second butt-jointed board 3 is then fixed to the second joist 42, either by means of a fixing piece 6 as previously described or by screwing.

[0091] Thus, each of the end-to-end boards 2, 3 rests, on one side, on a joist 41, 42 and on the other side, on the first joining piece 5. Thus, even when a force is applied to the ends 21, 31 of the end-to-end boards 2, 3, the joining piece 5 prevents them from bending by transferring the forces to the first support board 1. The latter, resting against the joists 41, 42, supports the ends 21, 31 of the end-to-end boards 2, 3.

[0092] THE Figures 5 And 6show the unfolding of an additional step to reinforce the butt joint.

[0093] The butted blades 2, 3 each have a second edge 24, 34. This corresponds, for example, for each of the blades 2, 3, to the edge opposite the first edge 23, 33 described previously. According to an example, for each butted blade 2, 3, the two edges are arranged symmetrically with respect to a median plane of said blade 2, 3, the median plane extending along a principal direction of extension of the blade 2, 3 (here along a direction parallel to the Y axis of the orthogonal coordinate system {X; Y; Z}). The said second edge 24, 34 of each blade to be joined 2, 3 also has a groove 240, 340 extending at least over a portion of the edge and to the end 21, 31. This groove separates, at least in the vicinity of the end 21, 31, the edge 24, 34 into two substantially parallel lips, a lower lip 241, 341 and an upper lip 242, 342.The lower lips 241, 341 can extend from a part of the cant 24, 34 and up to the end 21, 31 or even over the whole cant 24, 34, from one end to the other.

[0094] The reinforcement also requires a second support blade 1 and a second connecting piece 5. This second support blade 1 and the second connecting piece 5 will be fixed to the butt blades 2, 3 already installed to allow a transfer of force onto the second support blade 1.

[0095] The second support blade 1 has a second edge 12 with a groove 120 separating, at least locally, the edge 12 into two lips 121, 122 (not visible on the Figures 1 , 5 And 6 ). The second connecting piece 5 is similar, or even identical, to the first connecting piece 5 described with reference to the figures 2a And 2bIn particular, the first and second grooves 51, 52 are configured to cooperate, respectively, with each of the lower lips 241, 341 of the second edges 24, 34 of the butting blades 2, 3 and the lower lip 121 of the second edge 12 of the second support blade 1.

[0096] As previously stated, it is advantageous that all blades 1, 2, 3 implemented are identical or structurally similar so that they can be interchanged without affecting the assembled cladding.

[0097] The reinforcement of the butt joint includes, initially (for example, illustrated by the figure 5The second joining piece 5 is attached to the first and second butted boards 2 and 3, the latter being already butted together. The second joining piece 5 can therefore be inserted onto the lower edges 241 and 341 of the second edges 24 and 34 of the first and second butted boards 2 and 3 in a single step. For example, the second joining piece 5 is positioned so that the first groove 51 is aligned with the lower edges 241 and 341 of these second edges 24 and 34, and then inserted onto these lower edges 241 and 341, for example, using a mallet. The mere presence of the second joining piece 5 already keeps the butted boards 2 and 3 aligned, thus providing greater strength under stress.

[0098] The second connecting piece 5 is, for example, placed opposite the first connecting piece 5 already installed. It is, for example, positioned between the first and second joists 41, 42.

[0099] In a second stage (for example, illustrated by the figure 6 ), the reinforcement of the butt joint may include fixing the second support blade 1 onto the second joining piece 5. The lower lip 121 of the second support blade 1 is for example inserted into the second groove 52 of the second joining piece 5. The second support blade 1 is then fixed against the first and second joists 41, 42.

[0100] In this way, a force exerted on the end-to-end blades 2, 3, at the level of one and / or the other of the ends 21, 31 is transferred to the two support blades 1, arranged on each side of the end-to-end blades 2, 3. This force is then transferred to the joists 41, 42 against which the support blades 1 are fixed.

[0101] The figure shows a variant of the connecting piece 5. This variant may have an additional member 59 extending parallel to the upper members 53 and lower members 56. The web 54 of the connecting piece then extends beyond the upper member 53 to join the additional member. The connecting piece 5 then has additional grooves 51', 52' that can cooperate with the upper lips 232, 332, 112 of the blades 1, 2, 3. In this way, the connecting piece 5 corresponds to two connecting pieces 5 as described previously (for example, with reference to the figures 2a And 2barranged end-to-end, one on top of the other, with the upper members 53 overlapping. The dimensions of the additional grooves 51', 52' can therefore be based on the dimensions of the grooves 51, 52. The additional member 59 can also be dimensioned like the upper member 53 or the lower member 56. The additional grooves 51', 52' can also have additional teeth 55' to bite into the blades. These additional teeth 55' can be dimensioned like the teeth 55 of the first and second grooves 51, 52.

[0102] The steps and lessons relating to end joining, described above, can be repeated by considering the second support blade 1 as the new starting point, that is to say as a first support blade 1.

[0103] The invention is not limited to the embodiments previously described and extends to all embodiments covered by the invention.

Claims

1. Method for joining (9) boards from: • a first joist (41) and a second joist (42) adjacent to each other; • a support board (1) having an edge (11), said edge having a groove (110) separating, at least in part, the edge into a lower lip (111) and an upper lip (112); • a first board to be joined (2) and a second board to be joined (3), the two boards to be joined each having an end (21, 31) and at least a first edge (23, 33), said first edge of each board to be joined having a groove (230, 330) separating, at least in the vicinity of the end, the first edge into a lower lip (231, 331) and an upper lip (232, 332);and • a joining piece (5) comprising a first groove (51) and a second groove (52) and an upper member (53), the two grooves being arranged back to back, the upper member forming a wall of the first groove and a wall of the second groove, the upper member being configured to cooperate with the groove of the support blade, the first groove (51) being configured to cooperate with the lower lip of the support blade, the upper member being configured to cooperate with each of the grooves of the first and second blades to be joined and the second groove being configured to cooperate with each of the lower lips of the first edges of the first and second blades to be joined, the joining process comprising the following steps: • fixing (91) the support blade onto the first and second joists;• fix (92) the joining piece on the support board by inserting the upper flange of the joining piece into the groove of the support board and by inserting the first groove of the joining piece on the lower lip of the support board, the joining piece being positioned between the first joist and the second joist; • fix (93) the first end-jointed board on the joining piece by inserting the upper flange of the joining piece into the groove of the first end-jointed board and by inserting the lower lip of the first edge of the first end-jointed board into the second groove of the joining piece and leaving a portion of the second groove of the joining piece free, the first end-jointed board resting on the first joist;• fix (94) the second end-jointed board on the joining piece by inserting the upper flange of the joining piece into the groove of the second end-jointed board and by inserting the lower lip of the first edge of the second end-jointed board into the free portion of the second groove of the joining piece, the second end-jointed board resting on the second joist; the joining piece being supported only by the support board and the first and second end-jointed boards.; 2. End-jointing method (9) according to claim 1, wherein the first and second blades to be joined (2, 3) each have a second edge (24, 34), said second edge of each blade to be joined having a groove (240, 340) separating, at least in the vicinity of the end (21, 31), the second edge into at least a lower lip (241, 341) and an upper lip (242, 342), the end-jointing method comprising a reinforcement of the end joint from: • an additional support blade (1) having an edge (12), said edge having a groove separating, at least in part, the edge into a lower lip and an upper lip; • an additional connecting piece (5) comprising a first groove (51), a second groove (52) and an upper member (53), the two grooves being arranged back to back, the upper member forming a wall of the first groove and a wall of the second groove,the upper member being configured to cooperate with each of the grooves of the second edges of the first and second blades to be joined, the first groove being configured to cooperate with each of the lower lips of the second edges of the blades to be joined, the upper member being configured to cooperate with the groove of the additional support blade, the second groove being configured to cooperate with the lower lip of the additional support blade,the reinforcement of the butt joint comprising the following steps: • fix (95) the additional joining piece on the first and second boards to be butted by inserting the upper member of the additional joining piece into the groove of the second edge of the first board to be butted and into the groove of the second edge of the second board to be butted and by inserting the first groove of the additional joining piece on the lower lip of the second edge of the first board to be butted and on the lower lip of the second edge of the second board to be butted,the additional joining piece being positioned between the first joist (41) and the second joist (42); • fix (96) the additional support board onto the additional joining piece by inserting the upper flange of the additional joining piece into the groove of the additional support board and by inserting the lower lip of the additional support board into the second groove of the additional joining piece; and • fix (97) the additional support board onto the first and second joists, the additional joining piece being supported only by the additional support board and the first and second boards to be joined.

3. Method according to any one of claims 1 or 2, wherein the insertion of the upper member (53) of the connecting piece (5) into the groove (110) of the support blade (1) and the insertion of the first groove (51) of the connecting piece (5) onto the lower lip (111) of the support blade (1) are achieved by a movement of the connecting piece oriented perpendicular to the edge (11) of the support blade.

4. A method according to any one of claims 1 to 3, wherein the insertion of the upper member (53) of the joining piece (5) into the groove (230) of the first butt-jointed blade (2) and the insertion of the lower lip (231) of the first edge (23) of the first butt-jointed blade (2) into the second groove (51) of the joining piece (5) is achieved by a displacement of the first butt-jointed blade oriented perpendicular to the edge (11) of the support blade.

5. A cladding assembly, obtainable by means of the process according to any one of claims 1 to 4, comprising: • a first joist (41) and a second joist (42) adjacent to each other; • a support board (1), having an edge (11) having a groove (110) separating, at least in part, the edge into a lower lip (111) and an upper lip (112); • a first butt-jointed board (2) and a second butt-jointed board (3), the two butt-jointed boards each having an end (21, 31) and a first edge (23, 33), said first edge of each butt-jointed board having a groove (230, 240) separating, at least in the vicinity of the end, the first edge into a lower lip (231, 331) and an upper lip (232, 332); and • a connecting piece (5) comprising a first groove (51), a second groove (52) and an upper member (53), the two grooves being arranged back to back,the upper member forming a wall of the first groove and a wall of the second groove, the member being configured to cooperate with the groove of the support board, the first groove being configured to cooperate with the lower lip of the support board and the second groove being configured to cooperate with each of the lower lips of the first edges of the first and second boards to be joined, the support board being fixed to the first and second joists, the joining piece being fixed to the support board, the upper member of the joining piece being inserted into the groove of the support board, the first groove of the joining piece being inserted on the lower lip of the support board, the joining piece being positioned between the first and second joists, the first board to be joined being fixed to the joining piece,The upper flange of the joining piece being inserted into the groove of the first board to be joined, the lower lip of the first edge of the first board to be joined being inserted into a first part of the second groove of the joining piece, the first board resting on the first joist, the second board to be joined being fixed to the joining piece, the upper flange of the joining piece being inserted into the groove of the second board to be joined, the lower lip of the first edge of the second board to be joined being inserted into a second part of the second groove of the joining piece, the second board resting on the second joist, the joining piece being supported only by the support board and the first and second boards to be joined.

6. Assembly according to claim 5, wherein the fit between the first groove (51) of the connecting piece (5) and the lower lip (111) of the support blade (1) is configured so that the first groove of the connecting piece and the lower lip of the support blade cooperate by clamping, said fit being preferably chosen to allow insertion of the lower lip of the support blade into the first groove of the connecting piece by hand or by means of a mallet operated by a user.

7. Assembly according to any one of claims 5 or 6, wherein the fit between: the second groove (52) of the joining piece (5) and the lower lip (231) of the first edge (23) of the first butt-jointed blade (2); and • the second groove (52) of the joining piece and the lower lip (331) of the first edge (33) of the second butt-jointed blade (3) is configured such that: • the second groove of the joining piece and the lower lip of the first edge of the first butt-jointed blade cooperate by clamping; and • the second groove of the joining piece and the lower lip of the first edge of the second butt-jointed blade cooperate by clamping, said fit being preferably chosen to allow insertion of the lower lips of the first edges of the first and second butt-jointed blades into the second groove of the joining piece by hand or by means of a mallet operated by a user.

8. Assembly according to any one of claims 5 to 7, wherein the joining piece (5) comprises a core (54) separating the two grooves (51, 52), said core forming a spacer between the lower lip (111) of the support blade (1) and the lower lips (231, 331) of the first edges (23, 33) of the first and second blades to be butted (2, 3).

9. Assembly according to any one of claims 5 to 8, wherein the, respectively, first and second grooves (51, 52) of the joining piece (5) comprise teeth (55) configured to bite into, respectively, the lower lip (111) of the support blade (1) and the lower lips (231, 331) of the first edges (23, 33) of the first and second blades to be butted (2, 3).

10. Assembly according to claim 9, wherein each tooth (55) forms an edge or point extending principally in a direction (X) perpendicular to the principal direction (Y) of extension of the core (54) of the connecting piece (5).

11. Assembly according to any one of claims 5 to 10, wherein the second groove (52) of the joining piece (5) includes a first protrusion adapted to form a spacer between the ends (21, 32) of the first and second blades to be butted (2, 3), said first protrusion separating the second groove into two portions.

12. Assembly according to any one of claims 5 to 11, wherein the joining piece (5) comprises a second protrusion (57) suitable for forming a spacer between the ends (21, 32) of the first and second blades to be butted (2, 3), said second protrusion being disposed on the upper member (53) of the joining piece.

13. Assembly according to any one of claims 5 to 12, wherein the connecting piece (5) comprises a lower member (56), extending parallel to the upper member (53) of the connecting piece (5), the lower member of the connecting piece forming another wall of the first groove (51) and another wall of the second groove (52), the lower member having a width (L56) strictly greater than a width (L53) of the upper member.

14. Assembly according to any one of claims 5 to 13, wherein the support blade (1), the first blade to be butted (2) and the second blade to be butted (3) have sections, considered perpendicular to a principal extension direction of the blades, which is identical, the support blade, the first blade to be butted and the second blade to be butted being preferably identical.