FR2553133A1 - Joint plate for timber beams - Google Patents

Abstract

The timber joining plate comprises a base section and opposed side sections (16) which form a U-shaped plate. At least the side sections have multiple projections (18) struck from the plates and extending into the space, defined by the base and side sections. The base section has similar projections and/or a number of holes to receive separate driven fasteners. The portions of the base and side sections immediately adljacent the corners of the U-section are free of any projections of holes.

Description

 This invention relates to improvements in the manufacture of wooden beams and particularly to improved methods and apparatus for manufacturing wooden beams with butted or entry lengths.

 In many applications in the building industry it is necessary to have beam lengths of considerable width and length in relation to their thickness, such as those which are used as scaffolding beams, floor sleepers, ceiling joists , rafters and others.

 With the current shortage of lumber and regulations on the central environment, it has become increasingly difficult to obtain the desired massive lumber in large sections and lengths, and in particular in flawless quality.

 It has been known in the past to get beams entered by gluing edge to edge two or more separate lengths of lumber. We also knew how to butt lengths of lumber to assemble them and / or by making machine interlocking configurations such as dovetail configurations, in the ends of lengths of lumber to butt. Experience has shown that the input beams and butted beams formed by these known methods are not satisfactory and are not very economical, such beams can only be used for applications which are essentially free of loads.

US patents NO 2,877,520, 3,011,226 and 3,016,586 as well as Australian patent NO 291,878 all describe forms of timber assembly consisting of timber elements only connected by metal plates bearing protrusions in the form of nails or teeth formed by stamping in the plane of the plate and entering into the wooden elements. Such plates are very effective for the manufacture of reinforcement of beams and other similar structures of beams formed from of several structural timber elements extending in different directions and interconnected to each other by the nail plates described, which are limited to flat connecting elements,
US Patent No. 3,305,252 describes another form of tooth plate which can be used as a corner connection for between employees on two or three surfaces of a structure which cuts another at an angle.

 United States patent N9 3,365,222 describes a wall anchor provided with a U-shaped element for receiving the cross member and a gusset-shaped projection which is fixed to the wall or to any other similar element. The element receiving the crosspiece has a number of inwardly projecting teeth or fixing means which are driven in or hammered into a crosspiece to fix the latter relative to the wall or to any identical element.

 US Patent No. 3,427,055 discloses another form of connecting element for corner assembly, carrying teeth of different heights to facilitate engagement of the teeth in the wooden elements forming the corner assembly without deformation of the connecting element plate.

 US Patent No. 4,318,628 describes a device for assembling and connecting two or more building elements, the device being constituted with seats for receiving the elements according to the desired relationship, and one or more locking projections intended to penetrate the elements. The projections extend from a bottom wall of each seat to engage and penetrate into an end surface of the respective elements.

 United Kingdom patent NO 1,579,794 relates to a modified form of fixing with a tooth plate which is particularly useful for assembling timber elements in angular relation.

 The fastening device comprises a folded plate carrying stamped teeth in each portion, at least some teeth having a rod-shaped portion projecting angularly and a tip portion which projects from the rod towards the portion of the plate.

This type of projection allows the fixing device to be pushed into position before the tip portions of each tooth are inserted into the structural timber elements to be assembled, the rod portion then being in the plane of the respective portion in plate. Teeth of this type are commonly referred to as "1st knee nails".

 Although the forms of prior art joining devices can be used to join lumber elements to form arch hangers, corner pieces and the like, it has been found that such joining devices are ineffective for structurally sound production of long lengths of butted lumber because the strength of such beams is reduced by the ability to hold projections or teeth driven into the sections of beams.

 It is therefore recommended to have an improved fastening device which is effective in producing structurally sound wooden beams by abutting or splitting lengths of structural timber.

 It is also recommended that methods and apparatus are available to produce butted and / or joined beams that are suitable for use in load bearing applications.

 It is also recommended to have an improved method of forming a butt joint between the adjacent ends of lengths of lumber, a method which is economical and results in a beam capable of carrying loads.

 It is also recommended to have methods and apparatuses for the production of entry and / or butted beams which provide another solution than massive beams of equivalent resistance by using sections more readily available and of better quality.

 According to one aspect of the invention, there is a junction plate for joining end to end the adjacent ends of lumber lengths, comprising a U-shaped plate having a base section and opposite side sections, at least the lateral sections each carrying a certain number of protrusions stamped in the mass and extending, during use, in said delimited space and / or the holes defined to receive the depressed fastening devices, these portions of the section of base and side sections immediately adjacent to the corners of the U-shaped plate being free of any protrusions and holes.

 Preferably, the base section has protrusions stamped in a mass and extending, in use, in the delimited space. The protrusions of the two lateral sections and of the base section may be of the “toggle nail type” or of the type with teeth commonly used in other known forms of assembly devices of the tooth plate type.

 The junction plate of the invention is preferably formed with the base section and the side sections essentially coplanar, although of modified shape, the side sections may form an angle with the base section. The base section is engaged in the lengths of beam to be assembled and the projections or fixings driven in the lengths of beams which are thus maintained according to an end-to-end assembly. The lateral sections are then folded around the sides of the lengths of timber and the projections stamped in the lateral sections are pressed into the opposite faces of the lengths of beam.

 The lengths of beam joined end to end are therefore securely joined, the junction plate engaging on three of their sides, the projections or the fastenings driven from the base section and the projections of the sections on the opposite side extending perpendicularly. together to lock the assembly plate and the beam sections.

 The portions of the base and side sections immediately adjacent to the corners of the U-shaped plate which are free of protrusions or holes ensure the structural integrity and rigidity of the assembly by providing areas along the corners which are not weakened by holes or protruding projections. The resistance of the junction plate is therefore improved by the rigid corner pieces and it resists the tensile and shear forces transmitted to the junction plate via the projections and / or the pressed fasteners.

 Preferably, the protrusions are embossed in the side sections of the junction plate so as to extend under approximately 900 relative to the plane of the respective side, although the projection angle may vary but preferably not more than 5 degrees of the right angle.

In a preferred form, the number of protrusions on each side section does not exceed five (5) protrusions per 6.45 square centimeters (1 square inch) of cross-sectional area.

 According to another aspect of the invention, there is a method for forming an end-to-end assembly between the adjacent ends of lengths of beams using a junction plate of the type described above, comprising the following stages; position and support the lengths of beam end to end, support the assembly plate with a base section of the latter engaged in the coplanar surfaces of said lengths of beam, press in the projections extending from the base section or fasteners passing through the holes of the base section in the lengths of butted beams and bending the side sections of said junction plate on the edges of the lengths of beam, so as to give this plate essentially the shape of a U the protrusions extending from said side sections in the opposite sides of the lengths of beams.

 In one version, said folding is carried out by a shaping action using a shaping roller which engages in contact with the surface of one of the lateral sections opposite the surface from which the projections extend, the shaping roller. moving in a direction perpendicular to the plane of the base section to laminate the side section in contact with the surface of the lengths of beams.

In another version, particularly when the junction plate is formed with the side sections extending at an angle to the base section, the side sections are folded so as to come into contact with the ribs of the length of beam under the action of opposite presses acting on the lateral sections and compressing the sections and the lengths of beam between them to bring the projections into the beam
The invention also includes an apparatus for implementing the method and comprising means for supporting beam lengths in a butt-to-butt joint, means for engaging a base section of a junction plate in a tight fit with the coplanar surfaces of said beam lengths butted with protrusions or fasteners, extending from said base section and firmly embedded in the beam lengths, and shaping means adapted to engage in the lateral sections of said junction plate and movable to bring said side sections into engagement with the opposite side surfaces of said lengths of beams, the projections extending from said side sections and being driven into the lengths of beams.

 In the most interesting versions according to the invention, the lengths of beams assembled end to end are connected by a pair of junction plates whose bases engaging in the opposite sides of the lengths of beams. The lengths of butted beams can then be used in any orientation and under any load.

 The present invention also includes a means for splicing together beams such as those produced as described above, in a butt connection comprising corrugated strip type fasteners driven into the lengths of adjacent beams in such a way that the fastening elements can be inserted to an approximately equal depth in each of the lengths of beams, the fastening element stanting at an angle of less than 800 or greater than 1000 relative to the plane of the engaged surfaces of the lengths of beam, alternate fasteners or alternating groups of fasteners extending from different angles.

 Preferably, the fastening elements are made of a metal strip of which at least the terminal portions have the corrugated shape. The central portion of the elements is preferably flat.

So that the invention and what it achieves is more fully understood, lton will now refer to the versions of the invention thanks to the accompanying drawings:
FIG. 1 is a side view from above of lengths of beams joined end to end and using a pair of junction plates of the present invention
Figure 2 is a view along lines 2-2 of Figure 1.

 Figure 3 is a top view of the end of a pair of junction plates connected to butted beam lengths, the plates having a modified shape.

 Figure 4 is a perspective view of the modified form of the junction plate before it is engaged and fixed to the lengths of butted beams.

FIG. 5 is a view showing a method and an apparatus for applying a junction plate to end portions butted with lengths of beam
Figure 6 is a view showing a second form of apparatus.

 Figure 7 is a view showing a third form of apparatus.

 Figure 8 is a side top view showing the means for splitting the beams together.

Figure 9 is an end view of one form of fastener and
FIG. 10 is a plan view of the element in FIG. 9.

DESCRIPTION OF THE PREFERRED VERSIONS
If we refer to Figures 1 and 2 of the drawings, the junction plate 12 of this version includes, in its active form, a base section 14 and side sections 16. Each of the base and side sections 14 and 16 have a certain number of protrusions 17 extending from the respective planes of sections 14 and 16 and which are preferably formed from the material of the plate by a stamping operation. The formation of the projections 17 therefore produces all of the slots 18 shown in FIG. 1.

As will be seen, the protrusions 17 extend essentially at right angles to the plane of the bottom section and the respective side sections 14 and 16, although deviations of up to 50 may occur.

The junction plate 12 being in the operative position engaged on the abutting end portions of the two lengths of beam 19, the projections 17 extending from the side sections 16 interlock with the projections 17 extending from the base section 14, assembling
thus securely the junction plate 12 at the beam lengths 19. Any load applied to a wooden beam formed by butted sections in accordance with the invention gives rise to tensile forces anddisclosure which are uniformly distributed through the junction plate 12, the sections of assembled beams acting practically as if the beam were in one piece. Naturally, the dimensions of the junction plate 12, the projections 17 and the beam lengths 19 will have to be chosen so as to ensure correct engagement between the junction plate 12 and the lengths of beam 19 to provide the necessary resistance.

The junction plate 12 is shown in FIGS. 1 and 2 in the operative position engaged with the lengths of butted beam 19. However, the plate 12 will normally be constructed in the form of a plate whose desired projections will have been stamped in the plate itself. - me. In one form of the invention, the flat plate is continuously formed from a roll of steel strip which passes through a stamping machine to form the projections. The material of the plate can then be rewound or cut to the desired lengths. The protrusions 17 can have any suitable shape - known in this
technical. Therefore, the projections 17 can be formed with barbs or teeth to engage more solidly in the lengths of beam 19.On can adopt if desired other orientations of the projections and corresponding openings thus formed. The protrusions 17 can all be of a single length or of variable lengths for particular purposes.

 Referring to Figures 3 and 4, they show a modified construction of the junction plate 12a which is identical to that of the previous version, except that the base section 14a is provided with holes 25 instead of protrusions. The holes 25 make it possible to use fixings, for example nails 20, to fix the base section 14a to one side of the lengths of butted beams 19. In addition, the plate 12a is partially pre-folded, as shown in FIG. 4, to facilitate its engagement with the lengths of beam 19 before the lateral sections are folded to reach the position engaged in the opening as shown in FIG. 3.

 As will be seen in the drawings, the junction plate 12 and 12a of the two versions has metal zones on the base section and the lateral sections ad- centesaacanglsqulsare free - of holes 18 and 25, which provides structural integrity of the plate along each angle which reinforces the rigidity and the resistance of the plate in service.

 In addition, the presence of these hole-free zones ensures that the edges of the assembled beam lengths are not split, therefore weakened, by protrusions or nails placed too close to the respective edges. If we refer to Figures 5 to 7, these represent three different forms of apparatus for applying a junction plate of the invention to butted beam lengths.

 FIG. 5 represents the apparatus for applying the junction plate 12 to the lengths of beam 19 using a press plate 21 and rollers 22. The junction plate 12 originally receives a flat shape from which a certain surface comes out on a surface number of projections 17.

The butted end portions of the beam lengths 19 being held together, the base section 14 of the plate 12 is engaged in the lateral surfaces of the beam lengths 19. The press 21, actuated hydraulically or pneumatically, pushes the base section 14 against the beam length surfaces 19 so that the protrusions 17 which exit therefrom penetrate into the wood.

 The shaping rollers 22 are then moved to come into contact with the lateral sections 16 of the plate 12 and if this movement of the rollers 22 continues in the direction of the arrows in FIG. 5, the lateral sections 16 will bend around the edges 23 of the lengths of beam 19. The lateral sections 16 are finally rolled to engage in the opposite lateral surfaces 24 of the lengths of beam 19 with the projections 17 leaving the two lateral sections 16 driven into the wood.

 The characteristic of this version of the invention is that the movement of the shaping rollers 22 initially bends the two lateral sections 16 so that the ends of the projections being closest to the edges 23 engaging in the lateral surfaces 24 at a distance from the edges 23 which corresponds essentially to the distance between the ends of the projections and the edges 23 before the engagement of the base section 14 in the beam sections 19. In other words, when the projections 17 located closest to the edges 23 are rolled and driven into the wood, these projections remain essentially perpendicular to the side sections 16 and the rolling action causes a net penetration, the result being that the projections are firmly pressed.

 Two stages of the roll forming of the side sections 16 for their engagement with the end portions 19 are shown in Figure 5 in dotted lines.

 Figure 6 shows a second form of apparatus designed for in use with a junction plate 12 having pre-folded side sections 16 and protrusions 17 protruding from the base section 14 and side sections 16. The lengths of butted beams 19 to be assembled are supported by a means (not shown) to allow the press plate 32 to push the base section 16 against a lateral surface of the beam length 19 so that the projections 17 penetrate into the wood.

 The opposite press plates 33 and 34 are then moved together to push the side sections 16 against the surfaces of the wood, the corresponding projecting 17 penetrating into the beam to be fixed there.

It has been found that, as a result of the density of the beam, the lateral sections 16 tend to bend around the points of engagement of these projections as close as possible to the corners 23 before these projections are pushed into the wood.

This tends to ensure that the projections move in an essentially perpendicular direction.

 FIG. 7 represents an apparatus similar to that of FIG. 5 except that instead of using shaping rollers to fold and fix the lateral sections 16, press plates 36 and 37 are articulated on the opposite side edges of the central press plate 38 so as to be able to pivot. the pivoting joints 39 ensure that the press plates 36 and 37 move along the arc necessary to bend and fix the lateral sections 14 of the junction plate 12 in its position. A hydraulic or pneumatic cylinder 41, connecting rods 42 and levers 43 transmit the pushing and holding forces necessary for the press plates 36 and 37.

 If reference is made to FIG. 8 of the drawings, this represents an entangled beam 26 having an upper sole 270 a lower sole 28 and sections of intermediate wood 29. In the version shown, the upper sole 27 is a length single wood while the bottom sole 28 is made of a butted wood pòter formed according to any of the versions of the invention described with reference to Figures 1 to 7. The junction plate 12 assembles securely together the two portions of the lengths of wood forming the bottom sole 28.

 The intermediate beam sections 29 are entered at the upper and lower flanges 27 and 28 using the fixing elements 31. The preferred fixing elements are illustrated in FIGS. 9 and 10 and constitute a variation of the version of fixing elements in corrugated metal strip. As shown in Figures 9 and 10, the fasteners of this version have a central section free of undulations and the undulations at each end are not parallel but extend at a certain angle to each other, d '' About 20.The formation of the fastener according to this method means that, when applied between two portions of beam, as shown in Figure 8, the fibers along the engaged surfaces of the beams do not directly carry any load, the load being applied by the corrugations to points spaced from the surface.

In addition, the inclination of the corrugations between them act together on the lengths of beams when the fasteners are driven into the beam sections.

 As shown in Figure 8, the fasteners 31 are driven into the beam sections 29 and the flanges 27 and 28 so as to extend at an angle of approximately 450 relative to the plane of the contacting surfaces. In addition, alternate fasteners extend in opposite directions so as to thus distribute the load applied to the beam between the flanges 27 and 28 and the intermediate beam sections 29 without the fastening elements 31 being subjected to forces of pure shear. The obliquity of the fastening elements 31 means that these elements are placed under tension or in compression and are therefore able to distribute the loads more uniformly along the beam and, at the same time, to prevent any relative movement between the various parts of the beams. .

It is believed that the optimum angle for the fasteners is 450, as shown, but we realize that angles greater or less than 450 can be used and still allow to take advantage of the advantage of the angular arrangement of the fasteners by relation to the plane of the surfaces in contact.

 It will also be appreciated that groups of fasteners can extend in one direction and that alternate groups of fasteners extend in the opposite direction. However, it is recommended that alternate fasteners extend in opposite directions so that a beam of any length can be produced without worrying about the direction of the fastening elements 31.

 By using the fasteners and junction plates of the invention as described, it is possible to produce a beam of relatively large cross-sectional area from sharply short beam lengths and of smaller cross-sectional area, intermediate beam sections 29, in particular consisting of falls and other short lengths which would be wasted differently.

 It will also be appreciated that the intermediate beam sections 29 can be joined end to end, although this is not essential.

Claims (6)

CLAIMS. 1. An entered wooden beam, characterized in that it comprises at least two wooden beams arranged edge to edge and a certain number of fastening elements driven into the lengths of adjacent beams, said fastening elements comprising corrugated strips and generally extending at an angle of less than 800 or greater than 100 with respect to the plane of the contacting wood surfaces, alternate fasteners or alternate fastening groups extending at different angles. 2. A wooden beam entered according to claim 1 characterized in that a central portion of said fastening elements is free of undulations. 3. A wooden beam entered according to claim 1 or claim 2, characterized in that the corrugations located at one end of each fixing make a certain angle with the corrugations located at the other end of each fixing. 4. A wooden beam entered according to one of claims 1 to 3, characterized in that at least one of said wooden beams comprises a beam assembled end to end. 5. A wooden beam entered according to one of claims 1 to 4, characterized in that at least three lengths of beam are fixed together edge to edge so as to form a beam having a central part provided with lower and upper flanges . 6. A wooden beam entered according to one of claims 1 to 5, characterized in that the fastening elements extend at an angle of about 450 relative to the plane of the surfaces in contact.