MULTIPLE JOINT FOR WOODEN BEAMS MAKING UP A GEODETIC OR SPATIAL STRUCTURE AND STRUCTURAL ASSEMBLY OBTAINED THEREWITH

Abstract: The subject of the present invention is a multiple-hinged metal joint (1) for wooden beams (9) making up a geodetic or spatial structure, consisting of a central body (10) provided with a supporting base (8) such as to form a support for the ends of laminated or solid wood beams (9) and an upper connection (6, 7) for fixing said end of each beam (9) which is shaped so that it can be fixed to said connection (6,7).

Description: The present invention concerns metal joints for assembling beam elements to create geodetic or spatial structures, in particular of the type comprising laminated or solid wooden beams. Among prefabricated building structures a very important part is played by structures consisting of rods arranged according to surface geodetics, owing to the different fields of application to which they lend themselves, such as, for instance, coverings for large structures (industrial, civil, sports installations etc.). In large prefabricated structures, however, apart from the problems connected with overall design, there exists a series of problems of the parts, which includes organization of the joints to carry out assembly of different parts produced to form a single body. US-A-4.671.693 discloses a joint for wooden beams according to the preamble of claim 1, comprising a central body provided with a base such as to create a support for the end of the beams and an upper connection for fixing said ends of the beams. However, in all embodiments of the joint described in this document bolts are inserted in the beams, which could cause the weakening of the wood. The object of the present invention is to provide an easy, safe and simple manner of joining the single laminated or solid wood rods making up geodetic or spatial structures, by use of metal joints. A further object is to create a joint that in no way spoils the aesthetics of the structure or causes weakening of the wooden parts due to the holes necessary for fixing bolts. The object has been achieved by creating a multi-hinged metal joint characterized by the features of the characterizing part of claim 1. The structural assembly according to the present invention comprises the above described joints and laminated or solid wood beams, the supporting ends of which can be tapered and provided with a metal element to complete the joint. This completing element is formed by a plate and an end part equipped with connections matching those on the central body, for example holes for the clamping bolts. The wooden beams are nailed to the metal plate which thus forms an upper end connection. The joint according to the present invention permits safe and easy joining of the various beams which, arranged along the surface geodetics, make up the covering framework. A further aesthetic advantage lies in the fact that no bolts or fixing assemblies such as brackets are visible on the inside of the structure, the nails that make the metal element fast to the beam being situated on the extrados of the covering. A preferred but not restrictive embodiment, relative in its size and number of assembled beams to a certain covering, of a joint according to the present invention is illustrated in the accompanying drawings in which: fig. 1 shows an exploded top view in reduced scale of a joint with a cylindrical central body; fig. 2 shows a side view, again in reduced scale, of the joint, partly cutaway along the line 2-2 of fig. 1, in which the wooden beam has been eliminated for greater clarity; fig. 3 shows a cross-section similar to that in fig. 2, but in reduced scale and in use; fig. 4 shows a bottom view on the left and a top view on the right of the joint in use. Figures 1 and 2 show the joint 1 consisting of a hollow cylindrical body 10 equipped with reinforcements 11. An upper projection 15 is equipped with holes 7 for connection to a completing element 2 of the joint attached to the end of the laminated or solid beam 9. This beam 9 rests on the base 8 of the body 10 between the radial wings 5 provided in said body 10. In the end part 3 of completing element 2 three oval holes 6 are disposed to allow fastening by means of bolts to cylindrical central body 10. Holes 7 are also provided on the wings 5 to accomplish assembly of the beam 9. Number 4 designates the metal plate that is joined by nailing (nails 12) to the beam 9. Figure 2 shows more clearly how the two parts making up the joint are joined together. The supporting base 8 is integral with the bottom part of the body 10 and forms a circular shelf, on which the beams 9 rest. These are fastened to the base by means of nails 13 (figure 4). Figure 3 shows a cross-section of the joint in use, in which the joining means between the various parts can be seen. In the top view (figure 4) the plates 4 fixed by the nails 12 to the laminated wood beams 9 are visible. The fastening of the wings 5 to two adjacent end parts 3 can also be seen, as well as the fastening of the latter to the upper projection 15 of the cylindrical body 10 by means of bolts and relative washers. In the bottom view the beams 9 can be seen fastened by nailing (nails 13) to the base 8 extending from the bottom surface of cylindrical body 10. As will be noted from the above, no bolts pass through the wood as this would weaken it.

Claims: A multiple metal joint for wooden beams (9) making up a geodetic or spatial structure, comprising a central body (10) provided with a base (8) such as to create a support for the ends of the beams (9) and an upper connection for fixing said end of the beams (9), characterized in that said central body (10) is provided with radial wings (5) that demarcate the space reserved for each single beam (9), and in that said upper connection consists of bolts (16) passing in holes (7) provided in the central body (10) and in the wings (5) and in respective holes (6) provided in completing elements (2) coupled to the supporting ends of the beams (9). A joint according to claim 1, characterized in that the completing elements (2) are formed by a metallic plate (4) which is joined to the beam (9) by means of nails (12), and an end part (3) equipped with said holes (6). A joint according to claim 1 or 2, characterized in that said central body (10) extends upwardly with a projection (15), wherein said holes (7) are provided. A joint according to claim 1, 2 or 3, characterized in that the central body (10) is hollow, in particular it is polygonal, even circular, in shape and has inner reinforcements (11). A joint according to claim 4, characterized in that the upper projection (15) is an extension of the hollow central body (10). A joint according to any one of the preceding claims, characterized in that one of each pair of holes (6, 7) is ovalized. A structural assembly comprising a plurality of joints according to any one of the preceding claims. A structural assembly according to claim 7, characterized in that all the connections are provided solely on the extrados of the geodetic structure.

Inventors: ALBERTANI, NATALE
Applicants: HABITAT LEGNO S.P.A.
Application year: 1988
Main classification: E04B1
IPC codes: E04B1