Gantry

Abstract: A gantry for spanning a road, for example in connection with the presentation of information to users of the road, comprises a lattice girder(1), which is constructed of at least one uppermost longitudinal element (4,5), a lowermost longitudinal element (6) and lattice elements (7) interconnecting these longitudinal elements, and, at each end of this lattice girder, a pair of upwardly converging legs (2,3). In order to increase stability, the uppermost longitudinal element passes over each pair of legs and is supported there by means of a bearing structure (10,11).

Description: The invention is related to a gantry for spanning a road, for example in connection with the presentation of information to users of the road, which gantry comprises a lattice girder, which is constructed of at least one uppermost longitudinal element, a lowermost longitudinal element and lattice elements interconnecting these longitudinal elements, and, at each end of this lattice girder, a pair of upwardly converging legs, the cross-section of said lattice girder being triangular and having the apex directed downard, the uppermost longitudinal element comprising two parallel structural parts interconnected by horizontal lattice elements. Such a gantry is generally known and installed on motor ways in the Netherlands. The girder is provided with welded triangular end plates, which are bolted onto correspondingly shaped, facing parts of the pair of legs. Gantries of this kind are commonly used for the attachment of billboards and/or traffic-lane signalling. The known gantries are produced from steel and are consequently very heavy. Moreover, the fastening of the girder to the legs is labour-intensive, so that the installation of the gantry causes a great deal of traffic obstruction. The object of the invention is to provide a gantry which does not have these problems. This object is achieved in that the uppermost parallel structural parts pass over each pair of legs and in that each pair of legs has, above the spot where they are fastened together, an outwardly protruding bearing structure, the width of which is approximately equal to the width of the uppermost longitudinal element, said uppermost longitudinal being supported on said bearing structure. In such a construction, once the legs have been installed, the girder is able to be directly supported in a stable manner on the bearing structure. In order to obtain this stable bearing structure, there is no need to fit bolt connections directly. As soon as the girder is installed, the crane truck can already be removed; the bolt connections can then be fitted. The advantage of this is that the traffic is only very briefly obstructed by the operations connected with the installation of the girder. Preferably, in that connection, the legs of each pair each have an obliquely upward running extension piece, directed away from the extension piece of the other leg, and the extremities of the extension pieces are each provided with a bearing structure for the uppermost longitudinal element. The structure of the gantry according to the invention is particularly suitable for aluminium construction. To this end, the uppermost longitudinal element comprises two parallel aluminium longitudinal profiles, which longitudinal profiles each possess a flat surface on their side facing the lattice elements. In addition, the longitudinal profiles can possess two flat base surfaces, which, in transverse section, enclose an angle which is approximately equal to the complement of the base angle of the triangle, which base angle is determined by that longitudinal profile. The lattice elements, which can equally consist of aluminium tubes, then need to be obliquely pared in one direction only, thereby making the girder easier to produce. Each longitudinal profile can further possess two flat side surfaces, which are each connected at right-angles to a base surface and are interconnected. The support afforded to the girder can be made very stable if each bearing structure has an obliquely upward running flange, the side surfaces of the longitudinal profiles facing away from each other being shut in between the associated flanges at each end of the girder. According to a preferred embodiment, the side surfaces of each longitudinal profile are interconnected by a curved surface and that curved surface is connected by means of an internal partition to both base surfaces. A longitudinal profile which is made in this way is extremely resistant to the compression forces to which it is exposed; moreover, the internal partition helps the gradual transmission of forces between the longitudinal profile and the lattice elements. The legs of each pair can each carry a U-shaped fastening piece, these fastening pieces being interconnected. These fastening pieces can be identical and asymmetrical. The legs and the fastening pieces can also be made of aluminium. In that case, the legs comprise a plurality of interconnected longitudinal segments. The invention will be explained in greater detail below with reference to the figures, in which: Figure 1 shows a perspective view of the gantry according to the invention, Figure 2 shows an enlarged detail of Figure 1, Figure 3 shows an alternative detail, Figure 4 shows a diagrammatic transverse section through the girder of the gantry, Figure 5 shows a transverse section through a pair of legs, Figures 6a and 6b show a detail of the girder. The gantry which is shown in Figure 1 comprises a girder 1 which is supported at both ends by a pair of legs 2, 3. The girder comprises two uppermost longitudinal profiles 4, 5, a lowermost longitudinal profile 6 and lattice profiles 7 which interconnect these longitudinal profiles. As illustrated in Figures 2, 3 and 5, the legs 2, 3 comprise, on their mutually facing sides, a U-shaped stirrup 8, which stirrups are identical and are fastened together by a plurality of bolts 9. In addition, the legs comprise extension pieces 10, 11 which are directed obliquely upward away from each other and on which the longitudinal profiles 4, 5 of the girder 1 are supported. The cross-section of Figure 4 illustrates the longitudinal profiles 4, 5, 6. These all comprise two flat base surfaces 12, 13, to which the lattice profiles 7 are welded. At the same time, they each comprise two flat side surfaces 14, 15, which are joined together by a curved surface 16. The curved surfaces are each connected by an internal partition 17 to the flat base surfaces 13, 14. As can be seen in Figure 5, the legs are made up of longitudinal segments 23, 24 which are welded together by means of fastening strips 26, 27. These segments are also welded together at the site of the joints 25. In Figures 6a and 6b, it can be seen that the lowermost longitudinal profile 6, in the variant of Fig. 3, supports a cable duct 18 by means of a flange 19. The cable duct is provided with a cover 20, which can be swung open to one side. The flange 19 has two strips 21 by which it is fixed to the lowermost longitudinal profile 6. The duct 18 and flange 19 are likewise illustrated in Figure 3. Here it is also evident that the cables are able to be conducted downward via an elbow piece 22.

Claims: Gantry for spanning a road, for example in connection with the presentation of information to users of the road, which gantry comprises a lattice girder (1), which is constructed of at least one uppermost longitudinal element (4, 5, 7), a lowermost longitudinal element (6) and lattice elements (7) interconnecting these longitudinal elements (4-7), and, at each end of this lattice girder (1), a pair of upwardly converging legs (2, 3), the cross-section of said lattice girder (1) being triangular and having the apex directed downard, the uppermost longitudinal element comprising two parallel structural parts (4, 5) interconnected by horizontal lattice elements (7), characterized in that the uppermost parallel structural parts (4, 5) pass over each pair of legs (2, 3) and each pair of legs (2, 3) has, above the spot where they are fastened together, an outwardly protruding bearing structure (10, 11), the width of which is approximately equal to the width of the uppermost longitudinal element (4, 5, 7), said uppermost longitudinal being supported on said bearing structure (10, 11). Gantry according to Claim 1, in which each of the legs (2, 3) of each pair has an obliquely upward running extension piece (10, 11), directed away from the extension piece (10, 11) of the other leg (2, 3), and the extremities of the extension pieces (10, 11) are each provided with a bearing structure for the uppermost longitudinal element (4, 5, 7). Gantry according to Claim 2, in which the uppermost longitudinal element (4, 5, 7) comprises two parallel aluminium longitudinal profiles (4, 5), which longitudinal profiles (4, 5) each possess a flat base surface (12, 13) on their side facing the lattice elements (7). Gantry according to Claim 3, in which the longitudinal profiles (4-6) possess two flat base surfaces (12, 13) which, in transverse section, enclose an angle which is approximately equal to the complement of the base angle of the triangle, which base angle is determined by that longitudinal profile (4-6). Gantry according to Claim 4, in which each longitudinal profile (4-6) possesses two flat side surfaces (14, 15) which are each connected at right-angles to a base surface (12, 13) and are interconnected. Gantry according to Claim 5, in which each bearing structure has an obliquely upward running flange, the side surfaces of the longitudinal profiles facing away from each other being shut in between the associated flanges at each end of the girder. Gantry according to Claim 5 or 6, in which the side surfaces (14, 15) of each longitudinal profile (4-6) are interconnected by a curved surface (16) and that curved surface (16) is connected by means of an internal partition (17) to both base surfaces (12, 13). Gantry according to one of Claims 4-9, in which the legs (2, 3) of each pair each carry a U-shaped fastening piece (8), these fastening pieces (8) being interconnected. Gantry according to Claim 8, in which the legs (2, 3) and the fastening pieces (8) are made of aluminium. Gantry according to Claim 9, in which the legs (2, 3) comprise a plurality of interconnected longitudinal segments (23, 24).

Inventors: GEHRELS DIRK, GEHRELS, DIRK
Applicants: ALCOA NEDERLAND BV, ALCOA NEDERLAND B.V.
Application year: 1996
Main classification: E04C3
IPC codes: E04C3, E01F9