EP3146119B1 - Pneumatic support - Google Patents

Description

The present invention relates to a pneumatic carrier according to the preamble of claim 1.

Pneumatic carrier of the type mentioned are known and are based on a cylindrical basic shape according to WO 01/73245 . This basic form has been further developed into a spindle-shaped carrier according to WO 2005/007991 . The advantage of such pneumatic carriers is their low weight and the extremely small transport volume, since the inflatable body can be folded up and the tension members can be designed as cables. A disadvantage of such pneumatic beams is that although they can carry high surface loads (load distributed over the length of the beam), they are only suitable for asymmetric loads to a limited extent compared to the possible surface load, in particular with regard to concentrated axle loads, which in particular means use as a bridge decisively hinders, since an axle rolling over a bridge, for example of a truck, represents a particularly unfavorable case in this respect.

A major weak point is the pressure member, which as a slender rod is at risk of buckling, but cannot be made more massive, otherwise the advantages of the pneumatic concept would be reduced.

figure 1 1 shows diagrammatically a pneumatic support 1, here helical, according to the prior art, with exaggerated thickness for the sake of clarity. Under operating pressure, an inflatable body 2 made of a flexible material keeps a pressure member 3 from a tension member 4 at an operable distance, with planking 5 again being indicated on the pressure member 3 for the sake of clarity, which enable driving over the bridge formed by the girder 1 should. The following thought model can explain how the carrier works:
If a load 6 acts on the planking 5 and thus on the pressure member 3, this is carried by the inflated body 2, which is under operating pressure, but which in turn rests on the tension member 4, which thus actually carries the load 6. As a result, the tension member 4 tends to dodge down, but this is not possible because the pressure member 3 the common end node 7 and 8, so that the ends of the tension member 4 keeps at a distance. End nodes designate those areas in which the compression member 3 and the tension member 4 are operatively connected to each other.

The result is that the tension member 4 is essentially only subjected to axial tension and the pressure member 3 is essentially only subjected to axial pressure, so that the tension member 4 can be designed as a cable and the pressure member 3 as a thin rod. However, a thin bar under pressure is at risk of buckling, with the result that the buckling limit of the pressure member 3 determines the load-bearing capacity of the carrier 1 .

In the case of a distributed load that acts in the direction of arrow 6 and that is distributed symmetrically over the length of the beam, as is the case with roof structures, there is a reduced risk of buckling, since buckling in one direction counteracts the load being applied by the load itself is reduced, while buckling in the load direction due to the pressing member 3 resting on the body 2 is reduced.

However, in the case of an asymmetric load, the pressure member sinks increasingly into the body 2 at the point of the load, and instead bulges elsewhere, with a tendency to bulge beyond the bearing surface on the body 2 and thus from this lift, resulting in an increased risk of buckling and thus relevant reduced load capacity of the carrier 1 result.

Figure 2a shows an improved spindle-shaped carrier 10 according to the WO 2005/042880 , which is provided with connecting elements arranged vertically (ie in the load direction and perpendicularly to the longitudinal axis of the beam 10), designed as pure tension members 11. The distance a between the tension members 11 can be optimized by a person skilled in the art with regard to the specific case.

In the event of an asymmetric load, the tension members 11 are suitable to a certain extent to prevent the pressure member 3 from lifting off the body 2 at a non-loaded location and thus buckling. The vertical tension members 11 only cause the compression member and tension member to deform approximately equally (similar deflection line), they are not suitable to reduce the magnitude of the maximum deflection. However, one arises on the spot Attachment point 12 for a tension member 11 a significant stress (for example, additional bending moments) in the pressure member 3, which in turn is undesirable.

Figure 2b shows a possible arrangement of the tension members 11 in a carrier 10 'according to WO 2005/042880 , Several tension members 11 being arranged in bundles at a distance to be determined by those skilled in the art and in a symmetrical arrangement to one another, each starting from a common attachment point 13 . This arrangement appears suitable for reducing the above-mentioned undesired stress in the pressure member 3, since the attack of the tension members 11 is distributed over a small distance opposite the point of attachment 13. But the reduction is only local.

Those skilled in the art recognize from the disclosure of WO 2005/042880 that the tension members 11 arranged at a distance a from one another advantageously increases the carrying capacity of the carrier 1 in the case of an asymmetric load, since the pressure member 3 is at reduced risk of buckling. (At this point it should be added that the tension member 4' in Figure 2b is also designed as a beam, so that it could also bear a load 6' acting from below, in which case the pressure member 3 would then be subjected to tensile stress).

A disadvantage of the arrangement according to the WO 2005/042880 is, however, that the pneumatic system is still heavily deformed under load. In particular, a tension member designed as a cable (but also a tension member designed as a long, thin rod) and the pneumatic body 2 enable movements which, in the event of a load, lead to a large deformation of the beam despite sufficient load-bearing capacity, be it with a distributed load and, reinforced, with an asymmetrically applied load, for example in the case of a bridge with traffic. The tension members 11 according to WO 2005/042880 dampen the tendency to buckling of the pressure member 3, 4', but in turn lead to local lifting of the tension member 4, which in turn promotes a deformation of the entire carrier 10' and ultimately reduces the desired success regarding buckling of the pressure member 3 again. This deformation or deflection of the beam 10,10' represents a problem particularly when it is designed as a bridge (also with roofs, for example during a storm), not least because of the risk of vibrations, as is the case, for example, with the flexible Millennium Bridge in London was. It goes without saying that in general bridges or girders for absorbing loads are advantageously designed to be as stiff as possible, since neighboring structures do not have to be designed for the corresponding movements, as is the case, for example as is the case with the planking or deck of a bridge or the structures supported by a girder. On the contrary, as mentioned with the example of the Millenium Bridge, if a carrier is too soft, it can mean that it cannot be used for the intended purpose despite having sufficient resilience.

Accordingly, it is the object of the present invention to provide a pneumatic support with improved rigidity.

This object is solved by a carrier according to the characterizing features of claim 1.

Due to the fact that the connecting element between the pressure member and the tension member extends in a zigzag shape over several connection points, pressure can be diverted from the pressure member into the tension member (although the connection elements are designed as tension members), so that between the pressure member and the tension member Shear stresses can be absorbed, analogously to the shear stresses in the web of a double T-beam. The arrangement according to the invention correspondingly stiffens a pneumatic support fivefold, for example, or tenfold in the case of the relevant asymmetric load, as will be shown further below using a simulation calculation.

The invention is explained in more detail with reference to the figures.

Figur 1

schematisch einen spindelförmigen Träger gemäss dem Stand der Technik,

Figur 2a

schematisch den Träger von Figur 1 mit vertikalen Zuggliedern,

Figur 2b

schematisch die Anordnung von Zuggliedern gemäss dem Stand der Technik in einem Abschnitt eines pneumatischen Trägers,

Figur 3

schematisch eine Ausführungsform des erfindungsgemässen Trägers,

Figur 4a und 4b

schematisch weitere Ausführungsformen eines erfindungsgemässen, aus Modulen bestehenden Trägers,

Figur 5a und 5b

schematisch eine Ausführungsform zur Festlegung des Verbindungselements an einem Druckglied oder an einem Zugglied,

Figur 6a

eine weitere, besonders als transportable Brücke für Fahrzeuge geeignet Ausführungsform in einem Längsschnitt,

Figur 6b

einen Querschnitt an der Stelle AA durch die Ausführungsform von Figur 6a

Figur 7

schematisch die Verbindung zwischen dem flexiblen und starren Teilen der Ausführungsform gemäss Fig 6a,

Figur 8a

den für eine Vergleichsrechnung verwendete pneumatische Träger gemäss dem Stand der Technik,

Figur 8b

den für die Vergleichsrechnung verwendete pneumatische Träger gemäss der vorliegenden Erfindung, und

Figur 9

vier Diagramme mit einem Vergleich der Deformationen des Druckglieds und des Zugglieds zwischen dem pneumatischen Träger gemäss dem Stand der Technik und gemäss der vorliegenden Erfindung, wobei einmal eine Last symmetrisch und einmal eine Last asymmetrisch am jeweiligen Träger angreift.

It shows:

figure 1

schematically a spindle-shaped support according to the prior art,

Figure 2a

schematically the carrier of figure 1 with vertical tension members,

Figure 2b

Schematically the arrangement of tension members according to the prior art in a section of a pneumatic carrier,

figure 3

schematically an embodiment of the carrier according to the invention,

Figure 4a and 4b

schematically further embodiments of a carrier according to the invention, consisting of modules,

Figure 5a and 5b

schematically an embodiment for fixing the connecting element to a pressure member or to a tension member,

Figure 6a

another embodiment, particularly suitable as a transportable bridge for vehicles, in a longitudinal section,

Figure 6b

a cross-section at point AA through the embodiment of FIG Figure 6a

figure 7

schematically the connection between the flexible and rigid parts according to the embodiment Figure 6a ,

Figure 8a

the pneumatic carrier used for a comparative calculation according to the prior art,

Figure 8b

the pneumatic support used for the comparative calculation according to the present invention, and

figure 9

four diagrams with a comparison of the deformations of the pressure member and the tension member between the pneumatic carrier according to the prior art and according to the present invention, with one load acting symmetrically and one load asymmetrically on the respective carrier.

figure 3 shows schematically an embodiment of a beam 20 according to the invention. End nodes 21,22 enclose a number of pneumatic pressure bodies 23 between them and form an operative connection between the pressure member 24 and the tension member 25, which are attached on opposite sides to the pressure bodies 23, along their length, issue. The pressure bodies 23 operatively space the compression member 24 and tension member 25 under operating pressure. The connection between the pressure member 24 and the tension member 25 brought about by the end nodes 21, 22 is such that the pressure forces acting in the pressure member 24 can be introduced into the tension member 25 and vice versa and can thus be absorbed by it.

A connecting element 26 is operatively fixed via connection points 27,27',27'' at several locations on the compression member 24, the tension member 25 and also at the end nodes 21,22, such that it zig-zags over at least several connection points 27,27 '.27" of the pressure member 24 and the tension member 25 extends in the embodiment shown without gaps from the end node 21 to the end node 22.

In the preferred embodiment shown, a further connecting element 28 also runs in a zigzag shape via further connecting points 29 through the carrier 20, preferably from the end node 21 to the end node 22. The use of several connecting elements 26, 28 results in smaller distances between the corresponding connecting points 27 to 27 " and 29 on the respective pressure member 24 or tension member 25, with the advantage that the buckling load of the pressure member 24 increases, since the relevant length is given by the distance between the connection points 27, 29. The connection elements 26 and 28 are preferably offset from one another arranged, as shown in the figure, namely in such a way that the connection points 27 to 27" and 29 assigned to them lie opposite each other.

The end nodes 21, 22 are rigid and supported on an external structure such as the ground or on another component. According to the figure, in the embodiment shown, they are designed so large that their height corresponds to the height of the adjoining pneumatic pressure body 23 . It is essential and independent of their respective geometric design that they connect the pressure member 24 to the tension member 25 in such a way that they can initiate the pressure or train exerted by them into the other member (tension member 25 or pressure member 24). Accordingly, the end nodes, as in the figures described below or as in figure 1 be shown smaller or designed so that, for example, the tension member acts directly on the end of the pressure member. As a result, there is an end node when the pressure member and the tension member are connected to one another directly or via an end element of any geometric design in such a way that the pressure acting in the pressure member is introduced into the tension member and the tension acting in the tension member is introduced into the pressure member, whereby This creates tension in the tension member and pressure in the pressure member.

The pressure member 24 essentially transmits axial pressure and is designed accordingly as a compression rod, while the tension member 25 transmits axial tension and is therefore designed to be flexible can be, for example as a rope. Of course, it is also possible to form the tension member 25 as a rod, but then in such a way that it can bear the tensile load that occurs during operation. The tension member 25 can thus preferably be designed to be pressure-resistant, so that the carrier 20 can also absorb loads from below than can be loaded on both sides from above (load P) and also from below, in the opposite direction of the load P.

Adjacent pressure bodies 23 abut under operating pressure with their right and left end faces 30, 31, resulting in the effect of a single pneumatic pressure body extending continuously from end node 21 to end node 22 over a length, which as such is also in accordance with the invention. The multiple pressure bodies 23 shown in the figure are easier to assemble and disassemble and, as shown below, allow the carrier 20 to be assembled from multiple carrier modules, which in turn can have advantages for transport and storage. Furthermore, the pressure bodies 23 operatively keep the pressure member 24 and the tension member 25 spaced from each other, at rest and in the event that a load P is applied to the beam.

Pressure bodies of the type shown are known per se to those skilled in the art; they can, for example, be made of textile and provided with a gas-tight coating.

As mentioned, the connecting element 26 runs in a zigzag shape through the length of the carrier 20, from connecting point 27 to connecting point 27 (or 27', 27") and, in the case of further connecting elements, for example connecting element 28 from connecting point 29 to connecting point 29 Preferably, a plurality of connecting elements are provided which extend in a zigzag shape through the carrier, each of which acts on its own connection points.

The connecting element 26, 28 is prestressed by the operating pressure in the pressure bodies 23, is therefore a tension member and can be correspondingly flexible, preferably designed as a cable. Next, the connecting element 26,28 is preferably designed as a continuous tension member (cable or chain, etc.). However, it is also according to the invention that it consists of individual sections 32, which merely extend from a connection point 27 (or 27', 27") or 29 (on the pressure member 24 or on the tension member 25) to another connection point 27 (or 27 ', 27") or 29 (on the tension member 25 or on the pressure member 24). Then it is also according to the invention, such sections 32, for example flexible, for example as a rope, or as Train (train) staffs. It follows that the connecting element 26,28 can be divided into individual sections 32, each of which extends from a connection point 27,29 on the pressure member 24 to an associated connection point 27,29 on the tension member 25 (or vice versa).

The connection points 27, 29 are preferably designed in such a way that the connection element 26, 28 (or their individual sections 32) are fixed directly to the pressure member 24 or to the tension member 25. However, it is also conceivable that the fixing takes place on the pressure body 23, since, as will be described in more detail below, the pretension in the connecting element 26, 28 generated by the pressure body 23 under operating pressure produces the effect according to the present invention.

The connection points 27, 29 are preferably designed in such a way that during operation the longitudinal axes of the sections 32 or the corresponding sections of the continuous connection element 26, 28 essentially intersect in the area (preferably on the neutral axis) of the pressure member 24 and the tension member 25 . At least in the case of a tension member 25 designed as a cable, this cannot always be exactly the case due to tolerances and displacements in the mounted carrier 20, but it is desirable, since otherwise the rigidity of the carrier 20 that can be achieved per se cannot be fully realized. The longitudinal axes of two connecting elements 26, 28 acting on the same connection point 27, 29 thus preferably intersect essentially in the interior of the pressure member and/or the tension member and particularly preferably on its neutral axis.

If the pressure bodies 23 are under operating pressure, the connecting element 26, 28 is prestressed, as mentioned. Under the effect of a load P acting, for example, at the location of the connection point 27', this pretension is reduced at the location of the affected connection point 27', such that only a correspondingly reduced tension is introduced into the opposite connection points 27''. This in turn has the consequence that that at the location of the connection points 27" the tension member 25 has to absorb the forces generated by the internal pressure of the pressure bodies 23' to an increased extent, ie the axial tensile forces acting in it are increased.

This effect is the same as if pressure were introduced into the connection points 27" via the sections 32', 32" - the connection element 26 or its sections 32', 32" are therefore ultimately designed as tension elements compression struts which act in the carrier 20 transverse forces, ie absorb the corresponding thrust, so that the carrier 20 is stiff. The effect of the connecting element 26 corresponds, for example, to that of the web in the double-T girder, which is subjected to a considerable shearing load and thus gives the double-T girder its rigidity.

The pneumatic carriers according to the prior art cannot absorb this thrust, are therefore flexible and show the corresponding deformations when loaded (see below for Figures 9a to 9c, which compare the deformation of a carrier according to the invention with a carrier according to the prior art show).

This also applies to the carrier according to the WO 2007/071101 which has a flexible, longitudinal web: the web is vertically prestressed, but not horizontally; there are no horizontal components of the prestressing forces generated by the internal pressure in the web. Even if horizontal force components were to occur, the web would be distorted under the corresponding oblique stress (direction of a section 32), with the result that the web could not absorb the shear. This is confirmed by the necessarily vertical and horizontal arrangement of the threads of the textile web shown: the web is completely yielding in an oblique direction, since the square lattice formed by the threads would be distorted into a parallelogram-like lattice. If, for the sake of simplicity, still in our double-T beam, a volume element of the web is examined more closely, the shear stresses generated by the shear force lead to shearing of the volume element in the vertical direction. Since the volume element remains in the state of equilibrium, shear stresses also act in the horizontal direction, with the result that the resultant of these shear stresses lie in the diagonal of the volume element, which is inclined at 45° to the vertical or to the longitudinal axis of the beam 20, to which the load P again attacks vertically.

This means that the sections 32 of the connecting element 26, 28 are preferably inclined at an angle of 45° to the longitudinal axis of the carrier 20, since the shear force absorbed by the shear force is then optimally absorbed and the carrier 20 is thus stiffened to the maximum. In other words, the preference is for those between two associated connection points 27′, 27″ engaging sections 32 of the at least one connecting link 26 are inclined at an essentially 45° angle to the longitudinal axis of the carrier 20.

In the case of a non-vertical load, a person skilled in the art can optimize the inclination of the sections 32 accordingly.

A full effect of the connecting element 26,28 presupposes that this is designed to stretch as little as possible, ie hard, as is the case with thin wire ropes. The object of the present invention can thus be achieved: the inventive pneumatic carrier consists, as before, of parts that have only minimal volume for transport or storage, hardly weigh, but can also have considerable asymmetrical or punctiform effects, comparatively extremely absorb large loads with a deformation reduced to 10% or even less - see the description of FIGS. 9a to 9c.

From the present description, there is thus generally a pneumatic support having a pressurizable, e.g. inflatable, body which, under operating pressure, operably spaced a compression member extending substantially along its length and a tension member also extending along its length, wherein Connection points are provided on the pressure member and on the tension member for at least one connection element that can be subjected to tensile stress and extends between the pressure member and the tension member, and the connection element between the pressure member and the tension member extends in a zigzag shape via a number of connection points both in the area of the pressure member and in the Area of the tension member extends.

The at least one connecting element preferably extends continuously through the carrier, over the entire length of the region that can be placed under pressure. If this is not the case, only a partial area of the pneumatic carrier is stiffened according to the invention, so that, for example, a joint is created in the carrier by a locally limited flexible point, which can make sense if it is to be connected to a moving structure there. However, such a joint is paid for by the fact that the properties of the entire carrier are no longer optimal and the specialist is therefore only reluctant to provide it.

Next is from the in the figure 3 From the embodiment shown, it can be seen that preferably the connection points 27, 27', 29 on the pressure member 24 and those 29, 27" on the tension member 25 of the pneumatic support 20 are at a distance and offset from one another by half a distance, such that the connection element 26 , 28 along the inflatable body in a regular zigzag line.

The Figures 4a and 4b show, schematically and in longitudinal section, modified embodiments of a carrier 33 ( Figure 4a ) and 38 ( Figure 4b ). The carrier 33 is designed in the shape of a spindle. The diameter of the carrier 33 thus changes over its length, with the result that the distance between the connecting points 27 , 29 of the connecting elements 26 , 28 also changes in order to keep them inclined at 45° to the longitudinal axis of the carrier 33 . This is also the case for the beam 38 which, thanks to its curved longitudinal axis, extends in an arc and is accordingly suitable for forming a roof for the area below it.

Figure 5a shows a preferred embodiment of a connection point 27,29 for a continuous connection element 26,28 ( figure 3 ). A counterpart 40 is connected to a base piece 42 with the aid of bolts 41 indicated by a dash and thus holds the connecting element 26, 28 in a fixed position. Its longitudinal axes 44, which, as mentioned above, intersect at the location of the pressure member 24 (or tension member 25), are indicated in dashed lines. The base piece 42 in turn is gas-tight via a retaining plate 43 in relation to the pressure body 23 ( figure 3 ) fixed. Figure 5b shows a cross section through the connection point 27,28 of Figure 5a .

Figure 6a shows a longitudinal section through a further embodiment of a carrier 50 according to the invention, which is designed as a bridge. The carrier 50 is constructed in the shape of a spindle, with a substantially straight pressure member 51 (favorable with regard to the buckling load) and an arcuate tension member 52 . Two connecting elements 57, 58 extend lengthwise through the carrier 50 from one end node 59 to the other end node 60, the sections of which located between the connecting points 55, 56 can also be designed as tension rods. Three pneumatic pressure bodies 61 to 63 abut at the end with a right end face 65,66 and a left end face 67 to 68 while the right end face 64 of the pressure body 63 and the left end face 69 of the pressure body 61 do not abut the end nodes 59,60.

The pressure member 51 is composed of segments 70 to 72 that can be detached from one another, as is the tension member 52, which has the segments 73 to 75. All segments 70 to 72 and 73 to 75 run over the length of the respective pressure body 61 to 63 assigned to them, so that detachable carrier modules 76 to 78, which are inherently rigid according to the invention, result (whereby the end carrier modules 76 and 78 are of course also their end knots 59,60 are detachable).

The carrier 50 thus has several, i.e. two, three or even more than the three carrier modules 76 to 78 shown as an example in the figure, into which it can be disassembled or from which it can be assembled, which in turn has advantages with regard to storage, Transport and assembly or disassembly brings.

The individual modules are connected together by operatively attaching the respective segments 70-72 of the compression member 51 and the respective segments 73-75 of the tension member 52 to each other via the connection points 80-87. This can be done via a simple screw connection or via another type to be determined by a person skilled in the art, such as a joint, for example, which allows the segments to be pivoted relative to one another but transmits compressive and tensile forces. Likewise, the end-side modules 76,78 are connected to the associated end nodes 59,60, with the end node 59 connecting points 80,84 to the associated segments 70,73 and the end node 60 connecting points 83,87 to the associated segments 72,75 in such a way connects with each other that the compressive forces acting in the pressure member 51 and the tensile forces acting in the tension member 52 can be introduced into the respective other member 52,51. For this purpose, the end nodes 59,60 can also be linked to the associated segments 70,73 and 72,75 only via the connection points 80,84 and 83,87.

As mentioned, in the mounted state the pressure bodies 61 to 63 abut one another at the front, which produces the effect of a single, continuous pressure body.

The fixed connection of the segments 70 to 72 (compression member) and 73 to 75 (tension member) in the assembled state results in a continuously stiff beam 50 according to the invention, the flexural rigidity of which is not weakened by the modular design compared to a non-modular beam. The connecting elements 57, 58 are then preferably in such a way Divided sections that they do not extend beyond one of the modules 76-78 also. Then attack at connection points 81,82,85,86, which are assigned to two carrier modules 76,77 or 77,78, respectively, the corresponding two sections of the connecting elements 57,58. On the other hand, of course, when using carrier modules, the connecting elements can be designed to be continuous, or consist of a number of sections, each of which only extends from one connection point to the other connection point.

In summary, the illustrated embodiment also shows that the pneumatic carrier according to the invention can be designed as a separate, modular carrier module 76 to 78 (or that such carrier modules can be provided for the carrier according to the invention), which in turn can be connected to another (such) carrier module 76 to 78 can be connected in such a way that these are fixed to one another at the front and the connection points 80 to 87 of the pressure members (in the figure: segments 70 to 72 of the common pressure member 51) and the tension members (in the figure: segments 73 to 75 of the common Tension member 52) also form attachment points for the connecting element. The pressure members and the tension members of the end-side support modules are connected to an end node, see the description of the end nodes 21,22 of FIG figure 3 .

In an embodiment of a pneumatic carrier that is not shown in the figures, the carrier modules (76 to 78) can be connected to one another in an articulated manner in such a way that the carrier (20) can be folded up, with the pressure member at one end of a rigid section being attached to the pressure member of the adjacent one rigid section and at the other end of the rigid section the tension member is articulated on the tension member of the other adjacent rigid section and the respective other pressure members and tension members of adjacent stiffer sections are releasably connectable to one another. Such a pneumatic carrier cannot be dismantled into the carrier modules, but it can still be folded together in a zigzag shape.

Figure 6b shows a cross section through the carrier 50 of FIG Figure 6a in the plane AA of the carrier module 77. Visible is the pressure body 62 composed of the flexible side sections 90,91 and the upper 92 and lower section 93, which is under operating pressure, with the upper and lower section 92,93 being rigid but sufficiently elastic here are in order to be able to yield to the load deformations of the carrier 50 which are small according to the invention (but of course still exist). The upper section 92 carries the segment 71 of the Pressure member 51, the lower portion 93, the segment 74 of the tension member 52, which segments 71,74 can be formed, for example, from a thin sheet and thus form a roadway or at least a support for a suitable planking.

The connections 95 between the side sections 90,91 and the upper and lower sections 92,93 are gas-tight and in figure 7 shown in more detail.

Four sets of connecting elements 57, 58 run side by side inside the pressure body 62, the course of which is indicated by dashed lines and the interfaces 95 (connecting elements 57) and 96 (connecting elements 58) with the plane AA can be seen.

The connecting elements 57,58 are fixed at the symbolically indicated connection points 56,57, for example according to FIG Figure 5a .

The figure shows in particular that several sets of connecting elements 57, 58 can be guided side by side, which allows an extra-wide carrier 50 to be formed. This is advantageous if, for example, two girders arranged next to one another would have to be provided for a bridge, the space between which would have to be covered by planking: in the case of girder 50 with a plank as in Figure 6b trained cross-section, the storage, transport and assembly costs can be advantageously reduced compared to a conventional design with two carriers.

Preferably, it is also possible for a person skilled in the art to design the segments 70 to 72 and 73 to 75 (Figure 6a) to be gas-tight, so that the upper 92 and lower section 93 can be omitted, with which the pressure bodies 61 to 63 then cover the flexible edge sections 90, 91 and the (rigid) segments 70-72 and 73-75. Alternatively, of course, the lower segments 73 to 75 of the tension member 52 can be designed as cables, which would then run four times next to each other according to the embodiment shown in the figure and would each be operatively connected to an associated set of connecting elements 57,58.

figure 7 shows schematically the connection point 95 between the flexible edge section 91 and the upper section 92, the flexible edge section being held by a clamping point 97. The clamping point 97 preferably has a symbolically indicated bolt 98 on which a counter-plate 99 is fixed to the upper section 92 (which is stiff here). The longitudinal edge 100 of the flexible edge section 91 is thickened by an end section 102 of the flexible section 91 folded over by a cable 101 and can thus no longer slip back through the clamping point 97 and is thus fixed gas-tight by the clamping. Those skilled in the art can form all of the junctions 95 in this manner or in any other suitable manner.

Figure 8a Figure 1 shows a prior art girder 105 having a compression body 106 and extending therein and spaced apart by vertical tension members 107. End nodes 108,109 operably connect compression member 110 to tension member 111.

Figure 8b shows an embodiment of a carrier 115 according to the invention with a pressure body 122, which extends from the carrier 105 ( Figure 8a ) differs by its continuous zig-zag connecting links 116,117. End nodes 118,119 operably connect a compression member 120 to a tension member 121.

A simulation by the applicant for the deformation of both supports 105, 115 with a load P _m acting in the middle and then with a load P _s acting on the side resulted in the deformations shown in the diagrams of FIGS. 9a to 9c.

• ▪ Länge L= 20 m, Höhe H = 2 m, Last P_m,s = 200 kN,
• ▪ Druckglied 110,120 und Zugglied 111,121 aus Stahl, Trägheitsmomente je I = 2×10⁷ mm⁴, Querschnittsfläche je F =7'000 mm², Breite Druckglied 110,111 und Zugglied 111,121 je b = 1.0 m,
• ▪ Innendruck im Druckkörper 106,122 p = 50 kN/m², woraus eine Vertikalkraft auf das Druckglied 110,120 und das Zugglied 111,121 von q = pa= 50 kN/m² folgt,
• ▪ Querschnittsfläche der vertikalen Zugglieder 107 und der Verbindungsglieder 116,117 je D = 900 mm², und
• ▪ Angriffspunkt der Last P_m im Abstand von 10 m und für die Last P_s im Abstand von 6 m vom linken Endknoten 108 der Träger 105,115.

Both carriers 105, 115 have the same dimensions for the comparative deformation calculation:

• ▪ Length L= 20 m, height H = 2 m, load P _m,s = 200 kN,
• ▪ Pressure member 110,120 and tension member 111,121 made of steel, moments of inertia each I = 2×10 ⁷ mm ⁴ , cross-sectional area each F = 7,000 mm ² , width of compression member 110,111 and tension member 111,121 each b = 1.0 m,
• ▪ Internal pressure in the pressure body 106.122 p = 50 kN/m ² , from which a vertical force on the pressure member 110.120 and the tension member 111.121 of q = pa= 50 kN/m ² follows,
• ▪ Cross-sectional area of the vertical tension members 107 and the connecting members 116,117 each D = 900 mm ² , and
• ▪ Point of application of the load P _m at a distance of 10 m and for the load P _s at a distance of 6 m from the left end node 108 of the beam 105,115.

und bei P_s $${\mathrm{\delta }}_{\mathrm{ObergurtP}}:=\begin{array}{c}\mathrm{Träger}115\\ \left(\begin{array}{c}0\\ -9.6\\ -12.1\\ -20.4\\ -15.4\\ -15.5\\ -13.1\\ -11.1\\ -6.7\\ -5.2\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{UntergurtP}}:=\begin{array}{c}\mathrm{Träger}115\\ \left(\begin{array}{c}0\\ -9.7\\ -17.3\\ -14.5\\ -19.2\\ -16.6\\ -14.8\\ -11.3\\ -10.2\\ -5.5\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{ObergurtT}}:=\begin{array}{c}\mathrm{Träger}110\\ \left(\begin{array}{c}0\\ -99.2\\ -171.4\\ -181.6\\ -116.2\\ -10.3\\ 94.4\\ 155.7\\ 144.3\\ 80\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{UntergurtT}}:=\begin{array}{c}\mathrm{Träger}110\\ \left(\begin{array}{c}0\\ -99.2\\ -172.1\\ -181.0\\ -117.2\\ -11.4\\ 93.4\\ 155.2\\ 143.6\\ 80\\ 0\end{array}\right)\end{array}$$

The numerical results for the calculated deformations ϑ are at P _m $${\mathrm{\delta }}_{\mathrm{upper\; beltP}}:=\begin{array}{c}\mathrm{<figure-callout\; id="115"\; label="carrier"\; filenames="imgf0010.png"\; state="\{\{state\}\}">carrier</figure-callout>}115\\ \left(\begin{array}{c}0\\ -7.6\\ -10.1\\ -15.5\\ -16.6\\ -21.3\\ -16.6\\ -15.5\\ -10.1\\ -7.6\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{lower\; chordP}}:=\begin{array}{c}\mathrm{<figure-callout\; id="115"\; label="carrier"\; filenames="imgf0010.png"\; state="\{\{state\}\}">carrier</figure-callout>}115\\ \left(\begin{array}{c}0\\ -7.7\\ -13.8\\ -14.6\\ -19.9\\ -19.3\\ -19.9\\ -14.6\\ -13.8\\ -7.7\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{upper\; beltT}}:=\begin{array}{c}\mathrm{<figure-callout\; id="110"\; label="carrier"\; filenames="imgf0010.png,imgf0011.png"\; state="\{\{state\}\}">carrier</figure-callout>}110\\ \left(\begin{array}{c}0\\ 8.0\\ 10.2\\ -14.8\\ -71.8\\ -107.0\\ -71.8\\ -14.8\\ 10.2\\ 8.0\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{lower\; chordT}}:=\begin{array}{c}\mathrm{<figure-callout\; id="110"\; label="carrier"\; filenames="imgf0010.png,imgf0011.png"\; state="\{\{state\}\}">carrier</figure-callout>}110\\ \left(\begin{array}{c}0\\ 7.9\\ 9.4\\ -15.2\\ -72.8\\ -107.0\\ -72.8\\ -15.2\\ 9.4\\ 7.9\\ 0\end{array}\right)\end{array}\mathrm{x}:=\begin{array}{l}\mathrm{position}\mathrm{from}\mathrm{<figure-callout\; id="0"\; label="Left"\; filenames="imgf0011.png"\; state="\{\{state\}\}">Left</figure-callout>}\\ \left(\begin{array}{c}0\\ 2\\ 4\\ 6\\ \mathrm{<figure-callout\; id="10"\; label="8th"\; filenames="imgf0002.png,imgf0003.png"\; state="\{\{state\}\}">8th</figure-callout>}\\ 10\\ 12\\ 14\\ 16\\ 18\\ 20\end{array}\right)\end{array}$$

and at _Ps $${\mathrm{\delta }}_{\mathrm{upper\; beltP}}:=\begin{array}{c}\mathrm{<figure-callout\; id="115"\; label="carrier"\; filenames="imgf0010.png"\; state="\{\{state\}\}">carrier</figure-callout>}115\\ \left(\begin{array}{c}0\\ -9.6\\ -12.1\\ -20.4\\ -15.4\\ -15.5\\ -13.1\\ -11.1\\ -6.7\\ -5.2\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{lower\; chordP}}:=\begin{array}{c}\mathrm{<figure-callout\; id="115"\; label="carrier"\; filenames="imgf0010.png"\; state="\{\{state\}\}">carrier</figure-callout>}115\\ \left(\begin{array}{c}0\\ -9.7\\ -17.3\\ -14.5\\ -19.2\\ -16.6\\ -14.8\\ -11.3\\ -10.2\\ -5.5\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{upper\; beltT}}:=\begin{array}{c}\mathrm{<figure-callout\; id="110"\; label="carrier"\; filenames="imgf0010.png,imgf0011.png"\; state="\{\{state\}\}">carrier</figure-callout>}110\\ \left(\begin{array}{c}0\\ -99.2\\ -171.4\\ -181.6\\ -116.2\\ -10.3\\ 94.4\\ 155.7\\ 144.3\\ 80\\ 0\end{array}\right)\end{array}{\mathrm{\delta }}_{\mathrm{lower\; chordT}}:=\begin{array}{c}\mathrm{<figure-callout\; id="110"\; label="carrier"\; filenames="imgf0010.png,imgf0011.png"\; state="\{\{state\}\}">carrier</figure-callout>}110\\ \left(\begin{array}{c}0\\ -99.2\\ -172.1\\ -181.0\\ -117.2\\ -11.4\\ 93.4\\ 155.2\\ 143.6\\ 80\\ 0\end{array}\right)\end{array}$$

The figure 9 shows the corresponding diagrams 120 to 123 with the deformations ϑ of the beams 105,115 based on the deformation (bending line) of their pressure members 110, 120 or their tension members 120,121, with the comparison being made once with a load P _m acting in the middle, see diagrams 120 and 121 and then with an asymmetrically applied load P _s , see diagrams 122 and 123. A diagram shows either the deflection line of the pressure members 110,120 (diagrams 120 and 122) or the deflection line of the tension members 111,121 (diagrams 121,123).

Diagram 120 shows the deformation of the pressure members 110,120 of the carriers 105,115 under the load P _m , with the pressure member 110 of the carrier 105 according to the prior art being displaced 107 mm downwards at the location of the applied load P _m , the pressure member 120 of the invention Carrier 115, however, only by 21 mm. It is also evident as the compression member 110 of the prior art carrier 105 bulges laterally but the compression member 115 does not.

Diagram 121 shows the deformation of tension members 111,121 for the centrally applied load P _m , the deformation of which is very similar to that of pressure members 110,120 according to diagram 120, which is likely to be due to the effect of tension members 107 arranged at a distance a.

In addition to the very similar deformation of the compression and tension members of the two girders (prior art - invention), the massively reduced deflection is striking, which in the case of girder 115 according to the invention still accounts for approx. 20% of that of girder 105 according to the prior art - Which is a consequence of the inventive arrangement of the connecting elements.

The diagrams 122 and 123 show the deformation of the pressure members 110,120 and the tension members 111,121 of the beams 105 (prior art) and 115 (according to the invention) due to the load P _s acting from the side. As expected, the pressure member 110 and the tension member 111 of the beam 105 are severely deformed, with a depression at the location of the load P _s and a bulge in the other half of the beam 105.

Surprisingly, the deflection of the pressure member 111 and tension member 121 of the beam 115 according to the invention is reduced even more than in the case of the centrally applied load P _m : the deformation of the beam 115 according to the invention is reduced from 181 mm (beam 105 according to the prior art) to a mere 20 mm, ie reduced to about 10%, again as a result of the arrangement of the connecting elements according to the invention.

It can be seen from diagrams 120 to 123 that the carrier 115 according to the invention solves the task set out at the outset and, in particular for asymmetrical loads, is significantly more resistant to bending than the pneumatic carriers according to the prior art. This stiffening is provided over the distance that the links are continuously zigzagged through the beam. In addition to the desired stiffening per se, this also means that the risk of buckling for the pressure member 120 is significantly reduced, which significantly increases the carrying capacity (or its safety factor for a specific load) of the carrier 115 compared to the carrier 105 of the prior art.

As mentioned above, the compression member is on the side where the load is applied to the pneumatic pressure body, and the tension member is on the side facing away from the load application. Furthermore, several sets of connecting elements can be arranged side by side ( Figure 6b ). However, it is also possible, especially for a load that is not always directed in exactly the same direction, to provide an additional pressure member or an additional tension member, which also has connection points for a connecting element, and between this additional pressure member or tension member and the single tension member or compression member another connecting element zigzag - to be provided in a jagged shape. As opposed to Figure 6b then the sets of connecting elements are not parallel but inclined to one another. According to the arrangement Figure 6b If necessary, the wide compression member 51 or tension member 52 can also be split into several parallel compression members or tension members, so that the result is an additional compression member and another tension member (to a first compression member or tension member), each with connection points for a another connecting element is provided, which extends between the further pressure member and the further tension member along these in a zigzag shape.

Claims (16)

1. A pneumatic carrier (20, 33, 38, 50, 115) comprising a pneumatically pressurizable body (23, 61, 62, 63) which under operating pressure operatively holds a pressure member (24, 51, 120) extending substantially over its length and a tension member (25, 52, 121) likewise extending substantially over its length in spaced relationship, and a tension-loadable connecting element (26, 28, 57, 58), connecting points (27, 27', 27", 29) being provided on the compression member (24, 51, 120) and on the tension member (25, 52, 121) for at least the tension member (25, 52, 121) extending between the compression member (24, 51, 120) and the tension member (25, 52, 121) and passing through the support (20, 33, 38, 50, 115), (25, 52, 121), characterized in that the connecting element (26, 28, 57, 58) between the compression member (24, 51, 120) and the tension member (25, 52, 121) extends in a zigzag manner over in each case a plurality of connecting points (27, 27', 27"29) on the compression member (24, 51, 120) and on the tension member (25, 52, 121) or over a plurality of connecting points on the tension member (25, 52, 121), 121) or over a plurality of connecting points on the pneumatically pressurizable body (23, 61, 62, 63), the pressure member (24, 51, 120) and the tension member (25, 52, 121) being free of joints at the connecting points (27, 27', 27", 29), and the connecting element (26, 28, 57, 58) being fixed at the connecting points (27, 27', 27", 29) assigned to it.
2. A pneumatic carrier according to claim 1, wherein said at least one connecting element (26,28) extends continuously through said carrier (20,33,38,50,115) along the entire length of said pressurizable area.
3. A pneumatic carrier according to claim 1 or 2, wherein this is formed as a carrier module (76, 77, 78) which can be connected to a further carrier module (76, 77, 78) in such a way that these are fixed to one another at the end faces and the connecting points (80 to 87) of the pressure members and of the tension members at the same time form fastening points (55, 56) for the connecting element (57, 58).
4. A pneumatic carrier according to claim 1, wherein the connecting element (26,28) is divided into individual sections (32,32',32") each extending from a connecting point (27,27') on the pressure member (24) to an associated connecting point (27") on the tension member (25).
5. A pneumatic carrier according to claim 1, wherein the connection points on the compression member (25) and those on the tension member (24) are spaced apart and offset from each other by half a distance, respectively, such that the connection member 26,28 extends along the inflatable body (23) in a regular zigzag line.
6. A pneumatic carrier according to claim 1, wherein the longitudinal axes of two connecting elements (26,28) engaging at the same connection point (27,27') intersect substantially inside the pressure member (24).
7. A pneumatic carrier according to claim 1, wherein the longitudinal axes of two connecting elements (26,28,32,32',32") engaging at the same connection point (27,27",29) intersect substantially inside the traction member (25,51,121).
8. A pneumatic carrier according to claim 1, wherein a plurality of connecting members (26,32) extending in a zig-zag manner through the carrier are provided, each engaging at a respective connecting point (27,27',27",29).
9. A pneumatic carrier according to claim 1, wherein the portions (32) of the at least one connecting member (26, 28) engaging between two associated connecting points (27, 27', 27", 29) are inclined substantially 45° to the longitudinal axis of the carrier.
10. A pneumatic carrier according to claim 1, wherein the connecting element (26,28) or a section (32) of the connecting element is formed as a flexible tension member, preferably as a rope.
11. A pneumatic carrier according to claim 1, wherein the tension member (25,52,121) is designed to be pressure-loadable.
12. A pneumatic carrier according to claim 3, wherein said carrier comprises a plurality of carrier modules (76 to 78).
13. A pneumatic carrier according to claim 12, wherein the carrier modules (76 to 78) thereof are hingedly connected to each other such that the carrier (20) is collapsible, wherein at one end of a rigid section the compression member is hingedly connected to the compression member of the adjacent rigid section and at the other end of the rigid section the tension member is hingedly connected to the tension member of the other adjacent rigid section and the respective other compression members and tension members of adjacent rigid sections are releasably connectable to each other.
14. A pneumatic carrier (38) according to claim 1, wherein the longitudinal axis thereof is curved, such that it is arcuate.
15. A pneumatic carrier according to claim 1, wherein said carrier additionally comprises a pressure member or a tension member with connection points for a connecting element, and between said additional pressure member or tension member and said single tension member or pressure member a further connecting element extends in a zig-zag manner.
16. A pneumatic carrier according to claim 1, wherein said carrier additionally comprises a further pressure member and a further tension member, each having connection points for a further connecting element, which extends between said further pressure member and said further tension member along the latter in a zig-zag manner.

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