EP0581054A1 - Node for reticular structure with double curvature, specially one layer structure - Google Patents

Abstract

In order to produce knot pieces for double-curved lattice support structures, preferably in a single-layer design with regard to their strength properties, with less weight and nevertheless to enable relatively strong curvatures of the lattice support structures, it is proposed that the node pieces (11) are at least largely frustoconical. Your plan contact surfaces (12) for the ends of the bars (10) of the lattice support structure include the same or substantially the same angle of inclination (α) with the extended main node axis (16) as the rest of the node wall. The angle of inclination (α) of the contact surfaces (12) to the extended main node axis (16) is decisive for the curvature of the lattice support structure. In the preferred embodiment of the invention, the wall thickness of the frustoconical node piece (11) is the same over the entire height H at its weakest points in the area of the contact surfaces (12). <IMAGE>

Description

The invention relates to a node piece for double-curved lattice support structures, in particular in a single-layer version, consisting of a hollow body with through holes for fastening screws for connecting the bars of the lattice support structure to the node piece, which is provided with flat contact surfaces for the ends of the bars.

Known such knot pieces (see MERO brochure D-852 / 1.89) consist of hollow cylinders or pipe pieces, on which the contact surfaces for the ends of the bars, depending on the curvature of the lattice support structure, are machined (milled) at an oblique angle to the elongated main axes of the hollow cylinder . This method leads to the fact that in the area of these contact surfaces the wall thickness of the hollow cylinder, from top to bottom, depending on the curvature of the supporting structure, may decrease considerably, which is unfavorable for the strength of these knot pieces. For relatively strongly curved lattice support constructions, therefore, hollow cylindrical node pieces with large wall thicknesses are required, but what is uneconomical. Finally, these node pieces have a correspondingly high weight and make assembly more difficult. The disadvantages explained above also apply in the same way to so-called cup knots and plate knots. Because even with these knot variants, the knot section, which has the contact surfaces for the ends of the rods, consists of a hollow cylinder. As is well known, the hollow cylinder knots and plate knots are used in single-layer lattice support structures, while the so-called cup knots are designed for two-layer lattice support structures.

The invention has for its object to avoid the shortcomings of the above-mentioned node pieces and to propose a more economical solution for double-curved lattice support constructions, which is also particularly suitable for relatively strongly curved support structures.

• a) das Knotenstück wenigstens zum größten Teil kegelstumpfförmig ausgebildet ist und
• b) die Anlageflächen für die Stirnenden der Stäbe den gleichen oder im wesentlichen den gleichen Neigungswinkel mit der verlängerten Knotenhauptachse einschließen wie der restliche Teil der Knotenwand, wobei der Neigungswinkel der Anlageflächen zur verlängerten Knotenhauptachse die Krümmung der Gittertragkonstruktion bestimmt.

According to the invention the above object is achieved in that

• a) the node piece is at least largely frustoconical and
• b) the contact surfaces for the end faces of the bars include the same or substantially the same angle of inclination with the extended main node axis as the rest of the node wall, the angle of inclination of the contact surfaces to the extended main node axis determining the curvature of the lattice support structure.

With such knot pieces, double-curved lattice support structures can also be produced economically with a relatively strong curvature, while at the same time improving the strength of the knot pieces is achieved. This is because the smallest wall thickness of the frustoconical node pieces in the area of the contact surfaces is the same or at least essentially the same over their height.

Embodiments of the invention emerge from the subclaims. For example, the frustoconical node piece can be provided with a bottom. This further improves the strength of the node piece.

According to further refinements of the invention, the frustoconical node piece can also be designed as a cup knot or as a plate knot.

The node pieces according to the invention can consist of metal (preferably as a forged part made of steel) or, if the requirements for the strength of the lattice support structure are lower, also of plastic (e.g. for support structures in the exhibition area).

Fig. 1

einen Auschnitt aus einer einlagigen, zweifach gekrümmten Gittertragkonstruktion mit kegelstumpfförmigen Knotenstücken gemäß der Erfindung im Schnitt;

Fig. 2

ein den Knotenstücken der Fig. 1 ähnliches Knotenstück im Schnitt sowie im vergrößerten Maßstab, an dem beispielsweise ein Stab einer Gittertragkonstruktion ähnlich Fig. 1 angeschlossen ist;

Fig. 3

eine Draufsicht auf das Knotenstück der Fig. 2 mit beispielsweise zwei angeschlossenen Stäben;

Fig. 4

eine weitere Schnittansicht des kegelstumpfförmigen Knotenstücks der Fig. 2 und 3;

Fig. 5

eine Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Knotenstücks in Form eines Napfknotens und

Fig. 6

eine Schnittansicht noch einer weiteren Ausführungsform des erfindungsgemäßen Knotenstücks als Tellerknoten.

The invention is subsequently explained with reference to the drawings of exemplary embodiments. Show it :

Fig. 1

a section of a single-layer, double-curved lattice support structure with frustoconical node pieces according to the invention in section;

Fig. 2

a similar to the knot pieces of Figure 1 knot piece in section and on an enlarged scale, to which, for example, a rod of a lattice support structure similar to Figure 1 is connected;

Fig. 3

a plan view of the node of Figure 2 with, for example, two connected rods.

Fig. 4

another sectional view of the frustoconical node piece of Figures 2 and 3.

Fig. 5

a sectional view of another embodiment of the node piece according to the invention in the form of a cup knot and

Fig. 6

a sectional view of yet another embodiment of the node piece according to the invention as a plate knot.

The lattice support structure shown in FIG. 1 for covering elements, not shown, is designed, for example, for a building dome and has frusto-conical node pieces 11, to which, for example, four rods 10 are connected, which consist of square tubes. For this purpose, the node pieces 11 have flat contact surfaces 12 for the ends of the rods 10 which are worked out on their outer circumference. The front ends of the bars 10 are cut perpendicular to the bar axes.

In the area of each contact surface 12, the node pieces 11 contain, for example, two symmetrically arranged through bores 13 for fastening screws, not shown in FIG. 1, which extend through bores 14 in bearing plates 15, which are welded into the ends of the rods 10.

In the embodiment of Fig. 1, the arrangement is such that the contact surfaces 12 for the ends of the rods 10 include an angle of inclination α with the extended main node axis 16, which is only slightly different from the corresponding angle of inclination β, for example Inner knot wall deviates. Otherwise, the wall thickness D of the truncated cone-shaped node piece 11 (FIG. 4) is the same over its overall height H. As FIG. 2 shows, the angles of inclination α of the contact surfaces 12 with respect to the extended main node axis 16 are preferably equal to the angle of inclination α of, for example, the inner wall 17 of the node piece 11 '. 2 and 3, the same parts are identified by the same reference numbers as in FIG. 1. With the reference numerals 18, the fastening screws for connecting the rods 10 to the node piece 11 'are designated. 1 and 2 also show that the angle of inclination α of the contact surfaces 12 with respect to the extended main node axis 16 determines the curvature of the lattice support structure. In the case of the node piece 11 ', the wall thickness is the same at its weakest points in the area of the contact surfaces 12 over the entire height H.

The embodiment of a node piece 11A shown in FIG. 5 has a frustoconical section with the height H corresponding to the exemplary embodiment according to FIG. 4, to which, as described above, rods 10 (indicated by dash-dotted lines in FIG. 5) are connected to contact surfaces 12 can be. In addition, this node piece 11A is provided with an outwardly curved base 19 and is therefore also referred to as a cup node. Rods 20 of a lower flange, partially indicated in dashed lines, can be connected to the base 19, for example via a screw connection, the threaded bolts of which are screwed into corresponding threaded holes in the base 19. This node piece 11A is therefore suitable for two-layer lattice support structures. Covering elements, not shown, can be supported directly on the rods 10, which form the upper chord.

The knot piece 11B shown in FIG. 6 as a further exemplary embodiment also comprises a truncated cone-shaped section with the overall height H, corresponding to the exemplary embodiments according to FIGS. 4 and 5, and additionally a flat bottom 21, on which a projection 22 projecting upwards is formed centrally. This node piece 11B, also referred to as a plate knot, is designed for single-layer, double-curved lattice support structures and also enables the covering elements to be placed directly on the bars 10. More bars 10 can be connected to this node piece 11B than in the exemplary embodiments according to FIGS. 4 and 5 (for example 5 to 10 bars), which depends on the structure of the lattice support structure.

Claims (4)

Node piece for double-curved lattice support structures, in particular in a single-layer design, consisting of a hollow body with through-holes for fastening screws for connecting the bars of the lattice support structure to the node piece, which is provided with flat contact surfaces for the ends of the bars, characterized in that a) the node piece (11) is at least largely frustoconical and b) the contact surfaces (12) for the ends of the rods (10) enclose the same or substantially the same angle of inclination with the extended main node axis (16) as the remaining part of the node wall, the angle of inclination of the contact surfaces (12) to the extended main node axis ( 16) determines the curvature of the lattice support structure. Knot piece according to claim 1, characterized in that the frusto-conical knot piece (11A, 11B) is provided with a bottom (19, 21). Knot piece according to claim 2, characterized in that the frustoconical knot piece (11A) is designed as a cup knot. Knot piece according to claim 2, characterized in that the frusto-conical knot piece (11B) is designed as a plate knot.

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