US20140290177A1

US20140290177A1 - Crossbeam and mounting method

Info

Publication number: US20140290177A1
Application number: US14/225,635
Authority: US
Inventors: Rainhard Nordbrock
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-03-26
Filing date: 2014-03-26
Publication date: 2014-10-02
Also published as: DE102014002666A1; EP2784238B1; EP2784238A2; EP2784238A3

Abstract

A crossbeam comprising an upper chord, a lower chord, and a plurality of webs. The upper chord is linear and disposed along an upper chord axis and comprises a plurality of suspension points arranged at intervals. The lower chord is disposed along a lower chord axis adjacently at a distance from the upper chord. The lower chord axis is in alignment with the upper chord axis. The webs connect the upper chord and the lower chord by welded constructions and are each disposed along a respective web axis that intersects the upper chord axis and the lower chord axis. The crossbeam also comprises a connection element disposed on the upper chord at each suspension point.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from German Patent Application No. DE 10 2013 005 275.0, filed Mar. 26, 2013, and German Patent Application No. DE 10 2014 002 666.3, filed Feb. 28, 2014, both of which are hereby incorporated by reference herein in their entireties.

FIELD

The invention relates to a crossbeam that can be used universally in event technology. A basic field of application is stagecraft which is used in ceremonies, concerts, including open air concerts, exhibitions and in the theatre, etc.

BACKGROUND

A crossbeam in event technology is a support and assembly structure, which can include a metallic material and is often known as a truss.
For example, DE 103 41 931 A1 describes a crossbeam which is configured as a lifting beam. A crossbeam of this type comprises an upper chord and a lower chord, said upper and lower chords being connected by a web. To reduce weight, the web can have cutouts. The upper chord and lower chord are formed from rolled profiled material. The connections of upper chord, lower chord and web are formed by welds (welded construction), the crossbeam can consist of a steel or of an aluminium alloy.
DE 10 2009 004073 A1 describes a mounting system for suspended suspension points for use in exhibition stands. The mounting system comprises at least one coupling, at least one cable-shaped connection element, connected to a support rail, and a suspension point. In this respect, the coupling can be attached to a mounting rail, for example, to a Halfen cast-in channel. In its upper region, the support rail has sliding blocks which are arranged at the end and are connected to the cable-shaped connection element by shackles and safety bolts. A suspension point for receiving the live load is provided in the lower region of the support rail.
DE 292751A describes an anchor rail, identified here as a slotted hollow reinforcing bar, consisting of a steel section with an anchorage on the back. An anchor rail of this type is also known as a Halfen cast-in channel and can be used in concrete.
U.S. Pat. No. 6,571,527 B1 describes a crossbeam in the form of an elongate structure with an upper chord formed from two angle sections and a lower chord arranged adjacently at a distance and formed from two angle sections. Webs connected by angle sections are arranged between the two angle sections of the upper chord and the two angle sections of the lower chord.

SUMMARY

In an embodiment, the present invention provides a crossbeam comprising an upper chord, a lower chord, and a plurality of webs. The upper chord is linear and disposed along an upper chord axis and comprises a plurality of suspension points arranged at intervals. The lower chord is disposed along a lower chord axis adjacently at a distance from the upper chord. The lower chord axis is in alignment with the upper chord axis. The webs connect the upper chord and the lower chord by welded constructions and are each disposed along a respective web axis that intersects the upper chord axis and the lower chord axis. The crossbeam also comprises a connection element disposed on the upper chord at each suspension point.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:

FIG. 1 shows an embodiment of a crossbeam with upper chord and lower chord in a first configuration,

FIG. 2 shows the crossbeam according to FIG. 1 in a second configuration,

FIG. 2 a shows the relative position of the axes along sectional line A-A in FIG. 2,

FIG. 3 shows two structurally identical crossbeams according to FIG. 1 or 2 to be strung together,

FIG. 4 shows a development of FIG. 3 with a clamping means,

FIG. 5 shows a crossbeam with a respective transmission mechanism arranged on the end face of the upper chord in a first configuration,

FIG. 6 shows a crossbeam according to FIG. 5 in a second configuration, and

FIG. 7 shows a detail of a connection element on the upper chord.

DETAILED DESCRIPTION

An aspect of the invention is to provide a crossbeam and a mounting method of the type mentioned at the outset, which crossbeam allows a more even distribution of the load over the system length thereof.
One advantage of the developed crossbeam is based on the fact that said crossbeam has a plurality of suspension points which allow a more even distribution of the load over the system length thereof. For this purpose, the suspension points are arranged on an upper chord of the crossbeam at intervals over the system length of the crossbeam and the upper chord can be detachably connected to a fixed anchor rail, for example to a Halfen channel, by a respective connection element associated with the corresponding suspension point. An anchor rail of this type can be configured as a C profile in cross section, said anchor rail being connected on the back to a supporting construction and the C-profile receiving the connection elements, for example hammer head bolts. The crossbeam is provided for suspended mounting on an anchor rail or supporting construction. The suspension points can be provided with connection elements at identical intervals over the system length of the crossbeam or of the upper chord. A respective connection element is thereby provided at each suspension point. The number of suspension points with associated connection elements can vary subject to requirements, for example in the case of extreme loads or for maximum safety.
In a first example, for a system length of the crossbeam or upper chord of 1000 mm and a maximum live load of 500 kg, for example four suspension points with a respective connection element associated with the suspension point can be provided. In a second example, for a system length of the crossbeam or upper chord of 1000 mm and a maximum live load of a few tonnes, for example twenty or thirty suspension points with a respective connection element associated with the suspension point can be provided.
The upper chord is configured linearly and is connected to a lower chord by webs. The axes of upper chord and lower chord are arranged in alignment and the axes of the webs intersect the axes of the upper chord and lower chord.
In this respect in one configuration, the lower chord without an active live load can be arranged parallel, i.e. linearly to the upper chord. In a further, second configuration, the lower chord without an active live load can have a convex curvature directed towards the upper chord. Thus in the second configuration, the lower chord has a pretension. When an active live load is applied, the originally convex curved shape of the lower chord is altered and it changes into a linear configuration form of the lower chord. If the live load no longer acts on the lower chord, then due to the pretension, the lower chord returns into the originally convex curved shape. In this configuration, the upper chord remains linear, i.e. non-deformed, whereas the lower chord with the webs is elastically deformed (with an active live load). If the crossbeam is also configured with reinforcing plates, connected in a material-uniting manner, then the reinforcing plates are also elastically deformed (under an active live load).
Another advantage is that substantially even loads are distributed in the region of each individual suspension point of the crossbeam in the case of a live load which can act on the centre of the lower chord. For an active live load, it is possible to prevent uneven load distributions on the crossbeam at the suspension points and also to prevent deflections, as are known in the case of conventional configurations of crossbeams or mounting systems with cables, particularly on the lower chord.
Another advantage of the developed crossbeam is that in one configuration, provided between upper chord, lower chord and the adjacent webs is in each case a reinforcing plate which is connected to the webs and to the upper chord and the lower chord by welded constructions. This measure provides a better reinforcement which, in the case of an active live load, appreciably reduces the compressive/tensile forces (elastic deformation), particularly in the region of the webs.
Another advantage is that in the case of the same live loads in respect of conventional crossbeams or mounting systems with cables, the crossbeam allows a lighter, shortened construction and a simple, compact crossbeam is provided thereby. This entails, for example, shorter mounting times and improved handling for the assemblers.
Another advantage is that the crossbeam can be of a modular construction and can thus be detachably connected to further, structurally identical crossbeams, strung together by coupling elements. By stringing together a plurality of crossbeams of this type, it is thereby possible to mount relatively long segments on a supporting construction, for example on a hall or stage ceiling at a low cost and this can also be carried out in a plurality of rows, if required. In a further configuration, coupling elements can be provided to connect the ends of the modularly constructed crossbeams. Depending on the configuration of the coupling elements, these crossbeams can be arranged in a linearly aligning manner and/or also at a right angle to one another or crossing one another, so that spatial structures can be formed by these crossbeam arrangements. For this purpose, if required, appropriate anchor rails can again be provided on the supporting construction and here as well, the crossbeams can be connected to the associated anchor rails at the provided suspension points by the connection elements.
Another advantage is seen in the fact that the crossbeam can be connected to a respective transmission mechanism in each case at the free end faces of the upper chord. Suitable transmission mechanisms are in particular a cardan transmission or cardan joints or a mechanical linkage. Each transmission mechanism is connected to a respective plate which can be or is mounted on an anchor rail or supporting construction, for example on a hall or stage ceiling, by connection elements, for example by hammer head bolts. Each plate can be connected to an anchor rail or Halfen channel by connection elements. In this respect, as already mentioned, a crossbeam of this type can have suspension points which are arranged on the upper chord at intervals over the system length of the crossbeam. However, these suspension points are not used in this case, because the two transmission mechanisms arranged on the end faces of the upper chord realise the connection to the respective plate or to the anchor rail or Halfen channel. Alternatively, in the case of crossbeams provided for use with a transmission mechanism, corresponding suspension points (over the system length) can be omitted even during production. The basic structure of the crossbeam described at the beginning remains unaltered.
Another advantage is that a load cell can be arranged in the region of a respective active live load to ensure that the permissible live load or shearing forces and/or tensile or compressive forces are not exceeded. This load cell can comprise an optical display or can be coupled in terms of signals or circuits with a display means and/or evaluation means. Depending on requirements, load cells of this type can be actively connected to the coupling elements or transmission mechanisms.
Another advantage is that a respective damping element can be arranged on each connection element in the configuration of a crossbeam with a plurality of suspension points arranged on the upper chord at intervals over the system length of the crossbeam and with a respective associated connection element. Thus, each connection element, for example a respective hammer head bolt can be detachably connected to a fixed anchor rail, for example to a Halfen channel. The use of damping elements allows at the suspension points or connection elements a more even distribution of the load over the system length of the crossbeam or on the upper chord. Due to the damping elements, the reaction forces on the connection elements (observed over the length of the system) of the crossbeam can be distributed more evenly. For this purpose, the damping elements have a sandwich construction and are actively connected to the respective connection element on the inner side of the upper chord of the crossbeam.
The invention will be described in more detail in reference to the figures.
A crossbeam 1 comprises a linear, i.e. a straight upper chord 2 and a lower chord 3 arranged at a distance therefrom, said upper chord 2 and lower chord 3 being connected by a plurality of webs 4. In particular, the upper chord 2 has in the axial direction a plurality of connection elements 6, arranged at intervals from one another, for example configured in each case as a screw connection or as supporting bolts. Hammer head bolts are suitable as connection elements 6 or as screw connections. The crossbeam 1 can be detachably fixed to a supporting construction 15 by these connection elements 6. In this respect, the upper chord 2 is of a linear configuration and comprises a plurality of suspension points A, arranged at intervals, a respective connection element 6 being arranged at each suspension point A of the upper chord 2.
In a first configuration, the lower chord 3 without a live load F is arranged parallel to the upper chord 2, i.e. it is arranged linearly. In a second configuration, the lower chord 3 without a live load F has a convex curvature directed towards the upper chord 2 and thus has a pretension.
In certain embodiments, the connection elements 6, configured particularly as hammer head bolts, can be detachably connected to a fixed anchor rail 14 (Halfen channel) which can be connected to the supporting construction 15. The upper cord 2 can have appropriate openings, for example holes 20 to receive the connection elements 6.
In a further embodiment, the individual connection elements 6 can be arranged on the upper chord 2 at uniform intervals from one another over a system length L corresponding to the respectively provided suspension points A.
The crossbeam 1 can include a steel or an aluminium alloy, and can be configured in one piece and the webs 4 can be arranged at a right angle or diagonally between the upper chord 2 and lower chord 3. A crossbeam 1 of this type can be formed from a hollow material (hollow profile) or from a solid material. The axis AO of the upper chord and the axis AU of the lower chord are arranged in parallel and the axes AS of the webs intersect the axes (AO, AU) of the upper chord and lower chord, as shown in FIG. 2 a. In one configuration of the crossbeam 1, corresponding clearances 5 can be provided between the upper chord 2 and the lower chord 3 as well as between the webs 4.
In an embodiment, it is possible to provide between the upper chord 2, lower chord 3 and the adjacent webs 4 a respective reinforcing plate 9 which is connected by welded constructions to the webs 4 and to at least parts of the inner sides 12, 13 of upper chord 2 and lower chord 3. The individual suspension points A with the respectively individually associated connection elements 6 can be provided in the region of the clearances 5. In the configuration with reinforcing plates 9, said reinforcing plates 9 can also have clearances 5 (FIG. 2) in the corner regions of the web 4 and the inner sides 12, 13 and also in the region of the connection elements 6. These clearances 5 (FIG. 2) are inevitably smaller than the clearances 5 without reinforcing plates 9 (FIG. 1). In a further configuration, a respective reinforcing plate 9 can have clearances 5 which are arranged parallel to the inner sides 12, 13 of upper chord 2 and lower chord 3 (FIG. 4). In the configuration according to FIG. 2, for reasons of clarity, only the elastic deformation on the lower chord 3 is shown.
The convex curvature, mentioned at the beginning, of the lower chord 3 can be a circular arc 8 and this arc 8 comprises an apex S which is arranged in the centre relative to the system length L of the crossbeam 1. The arc 8 can be delimited by a first end point E1 and by a second end point E2, the maximum distance thereof corresponding to the system length L of the crossbeam 1.
For example, in the case of a crossbeam 1 which is configured for a maximum permissible live load F of 500 kg, which consists of tubular material based on an aluminium alloy, has a system length L of 1000 mm, a system height H of 250 mm, has an upper chord 2, a lower chord 3 and webs 4 of a respective external diameter of 50 mm and a wall thickness of respectively 5 mm, the apex S of the arc 8 of the lower chord 3 can have a deflection x of at most 5 mm, i.e. x≦5 mm, with respect to the horizontal of the lower chord 3.
The crossbeam 1 has a system height H, delimited by the outer side 10 of the upper chord 2 and by the outer side 11 of the lower chord 3. The crossbeam 1 also has a specific system length L. The system height H and the system length L of crossbeams 1 can be of standard sizes. The crossbeam 1 can consist of steel or of an aluminium alloy. Upper chord 2 and lower chord 3 are connected via the webs 4 by means of a material-uniting connection, in particular by a welded construction. For this purpose, the webs 4 are connected in a material-uniting manner at their ends to an inner side 12 of the upper chord 2 and to an inner side 13 of the lower chord 3. Upper chord 2 and lower chord 3 as well as the webs 4 can be formed from a hollow profile having a circular or elliptical or polygonal cross section.
Provided in the central region of the lower chord 3 is a hold point which receives a sling gear 7. As shown in FIGS. 1 and 2, the sling gear 7 can be a ring bolt with an O-ring, releasably arranged in the lower chord 3. In the case of a load, the live load F engages on this sling gear 7. The crossbeam 1 is not restricted to a central arrangement of the sling gear 7. In fact, while bearing in mind the permissible live load F or live loads F, a plurality of sling gears 7, can be arranged symmetrically at intervals can be provided on the lower chord 3.
FIG. 4 shows by way of example an eccentric arrangement of a sling gear 7′. The sling gear 7′ can be a clamping means which can be releasably arranged on the lower chord 3. For example, the clamping means can be formed by half clamps 19. Half clamps 19 of this type are configured connected in two or more parts in half shell forms, are adapted to the cross section (circular or rectangular/square tube) of the lower chord 3 and engage around the lower chord 3 and can comprise an O-ring for attaching a live load F.
In an embodiment, a load cell 17 can be arranged as a measuring means in the region of a respective active live loaf F. Furthermore, load cells 17 of this type can be arranged on the clamping means (half clamps 19). A load cell 17 of this type can comprise an optical display or can be coupled in terms of signals or circuits with a display means and/or evaluation means 18.
In an embodiment, the crossbeam 1 can be of a modular construction and can be detachably connected to further structurally identical crossbeams 1′ (FIG. 3), strung together by coupling elements 16. By stringing together a plurality of crossbeams 1, 1′ to n of this type, it is possible to mount relatively large segments, for example on a hall or stage ceiling at a low cost, and this can also be carried out in a plurality of rows, if required. The coupling elements 16 can be arranged at one end on the upper chord 2 and at the associated end of the lower chord 3 of the first crossbeam 1 and according to FIG. 3 (double arrow), can be connected at the end in a detachable manner, for example, positively to the upper chord 2′ and lower chord 3′ of a further crossbeam 1′. The coupling elements 16 can be releasably connected to the crossbeams 1, 1′ by connection means, in particular by bolts. The coupling elements 16 for end connection of the modularly constructed crossbeams 1. 1′-n are not restricted to a linear (aligning) connection of two crossbeams 1, 1′. In fact, further coupling elements 16 can be configured as T-pieces for connecting three crossbeams 1, 1′, 1″ or as crosspieces for connecting four crossbeams 1, 1′, 1″, 1′″, so that the crossbeams 1-1″ can be arranged at a right angle to one another or can intersect one another (crossbeams 1-1′″). Due to coupling elements 16 of this type in connection with a plurality of crossbeams 1-n, it is possible to thereby form spatial structures, for example when used in stage technology.
For example, in the case of crossbeams 1, 1′ to n, having a respective system length L of 1000 mm, by stringing together 50 such crossbeams 1, 1′ etc on a supporting construction 15, for example on a hall or stage ceiling, it is possible to form a segment of 50 m and, if required, in a plurality of rows. Here again, in this stringing together arrangement, corresponding anchor rails 14 can be provided on the supporting construction 15 and the crossbeams 1, 1′-n can again be connected to the associated anchor rails 14 at the provided suspension points A by the connection elements 6.
When two crossbeams 1, 1′ are connected, it is possible to provide, for example, in the region of the coupling elements 16 in each case, at least one load cell 17 which can comprise an optical display or can be coupled with the display means and/or evaluation means 18 in terms of signals and/or circuits. As shown in FIG. 4, a load cell 17 of this type can be arranged externally on the upper chord 2 and on the lower chord 3. Alternatively, a load cell 17 of this type, including power supply and transmitter, can be arranged inside the upper chord 2 or lower chord 3 and/or inside the coupling elements 16.
The crossbeam 1 is not restricted to the described configuration with upper chord 2 and lower chord 3. In fact, at least one middle chord can be provided which is arranged in parallel between upper chord 2 and lower chord 3. Here again, the at least one middle chord is connected to the upper chord 2 and lower chord 3 by webs 4. If required, reinforcing plates 9 can be provided in the clearances 5. Upper chord 2 and lower chord 3 and the at least one middle chord as well as the webs 4 can be formed from a hollow profile having a circular or elliptical or polygonal cross section.
FIGS. 5 and 6 show configurations of the crossbeam 1 which are substantially structurally identical to the configurations described above. Here, the lower chord 3 without a live load F can also be arranged parallel to the upper chord 2 or it can have a convex curvature.
The axis AO of the upper chord and the axis AU of the lower chord are again in alignment, in the case in which the lower chord 3 is arranged parallel to the upper chord 2, the axes AO, AU are parallel and the axes AS of the webs intersect the axes of upper chord and lower chord (AO, AU). A crossbeam 1 has respectively on the free end faces of the upper chord 2 a respective transmission mechanism (21, 23, 24; or 21 to 24) rigidly connected to the upper chord 2. A transmission mechanism (21, 23, 24; or 21 to 24) of this type is configured to be structurally identical but mirror-inverted at each end face of the upper chord 2.
According to FIG. 5, the crossbeam 1 comprises a first joint 21 arranged in a fixed manner on the upper chord 2. The first fixed joint 21 is actively connected to a second fixed joint 23 arranged at a right angle on a plate 24. The two joints 21, 23 are connected by a supporting bolt.
According to FIG. 6, the crossbeam 1 comprises a first joint 21 arranged in a fixed manner on the upper chord 2. The first fixed joint 21 is actively connected to a coupling rod 22. The first fixed joint 21 and the coupling rod 22 can be connected by a supporting bolt.
Furthermore, the coupling rod 22 is actively connected to a second joint 23 arranged at a right angle in a fixed manner on the plate 24. The coupling rod 22 and the second fixed joint 23 can be connected by a supporting bolt.
The plate 24 according to FIGS. 5 and 6 can be mounted parallel to a supporting construction 15, for example to a hall or stage ceiling. For this purpose, each plate 24 has holes 20 for receiving connection elements 6. Thus, provided in each hole 20 is a connection element 6 which is connected to an anchor rail 14 or Halfen channel of the supporting construction 15. In this respect, as already mentioned, a crossbeam 1 of this type can have suspension points A arranged at intervals on the upper chord 2 over the system length L of the crossbeam 1. However, these suspension points A are not used in this case because the two transmission mechanisms, arranged on the end faces of the upper chord 2 realise, as suspension points A, the connection to the respective plate 24 or by the respective connection element 6, to the anchor rail 14 or Halfen channel. Alternatively, in the case of crossbeams 1 provided for use with a transmission mechanism, corresponding suspension points A or holes 20 in the upper chord 2 can even be omitted during production.
Alternatively, a respective coupling element 16 can be used as part of a transmission mechanism which, connected to the associated plate 24, is detachably arranged on the supporting construction 15 or on the anchor rail 14.
As shown by way of example in FIG. 6, the transmission mechanism (21, 23, 24; or 21 to 24) can be coupled in terms of signals or circuits on each end face of the upper chord 2 with a load cell 17 which has already been described. Each load cell 17 is coupled in terms of signals or circuits with a display/evaluation means 18 which has already been described.
To summarise, the upper chord 2 is configured linearly and, respectively arranged on the free end faces of the upper chord 2 is a respective transmission mechanism 21, 23, 24; or 21 to 24 which is rigidly connected to the upper chord 2. Each transmission mechanism 21, 23, 24; or 21 to 24 comprises a plate 24 which is detachably connected by connection elements 6 to a supporting construction 15 or anchor rail 14 (on the supporting construction 15). Without a live load F, the lower chord 3 is arranged parallel to the upper chord 2 or has a convex curvature. The axis AO of the upper chord and the axis AU of the lower chord are aligned and the axes AS of the webs intersect the axes AO, AU of upper chord and lower chord. When the lower chord 3 is arranged parallel to the upper chord 2, in addition to the axes AO, AU, being arranged in alignment, they are also parallel.
The mode of operation according to FIGS. 1 to 4 is as follows. The crossbeam 1 with a linear upper chord 2 and a lower chord 3 arranged adjacently at a distance therefrom, as well as a plurality of webs 4 connecting the upper chord 2 and the lower chord 3 in a material-uniting manner comprises the lower chord 3 in a state without a live load F in a parallel arrangement to the upper chord 2 or with a convex curvature directed towards the upper chord 2. The upper chord 2 is detachably connected to the supporting construction 15, alternatively to the anchor rail 14 (Halfen channel) arranged on the supporting construction 15 by the connection elements 6 at the suspension points A provided at intervals.
Thereafter, a live load F can be applied to at least one hold point (lower chord 3) with a sling gear 7. In this respect, in the first configuration, the lower chord 3 remains substantially parallel, i.e. it remains linear with respect to the upper chord 2. In the second configuration, the originally convex, pretensioned curved shape of the lower chord 3 is altered as a result of the active live load F and changes into a linear configuration form of the lower chord 3.
To avoid overloading or to prevent the safety of the crossbeam 1 from being compromised, the maximum live load F is to be established for each crossbeam 1. The hold point of the sling gear 7 can be arranged on a straight line, in the present example on the vertical, to the apex S of the convex curvature. If the live load F on the sling gear 7 is removed, the linear configuration form of the lower chord 3 changes back into the convex curved form (second configuration).
The illustration of the convex curvature of the lower chord 3 in FIGS. 1 and 2 is shown in this form merely to provide a clearer understanding and thus is not true to scale.
The connection elements 6 can connect the respective crossbeam 1 to the supporting construction 15 or to the anchor rail 14 with a defined torque. Under a safety aspect, the respective defined torques can be detected by data and documented.
In the case of the crossbeam 1 having a plurality of suspension points A arranged on the upper chord 2 at intervals over the system length L of the crossbeam 1, and having a respective associated connection element 6, a damping element 25 to 27 can be arranged on each provided connection element 6. FIG. 7 shows a connection element 6 of this type which shows by way of example a hammer head bolt 30 which is known per se with a threaded bolt 28. The associated anchor rail 14 is not shown for reasons of clarity and the hammer head bolt 30 is shown having not (yet) been rotated into the installation position. The hammer head bolt 30 (with threaded bolt 28) is arranged in the hole 20, associated with the corresponding suspension point A, on the upper chord 2 (outer side 10) of the crossbeam 1 and thereby penetrates the upper chord 2. The threaded bolt 28 protrudes by its free end into the clearance 5 on the inner side 12 of the upper chord 2. Arranged on the free end of the threaded bolt 28, in the axial direction of the threaded bolt 28 are a first disc 25, a disc-shaped damping material 26 and a second disc 27. The discs 25, 27 are formed from a metallic material, for example steel, and have a hole which is actively connected to the threaded bolt 28. The damping material 26 can include an elastomer or contain at least one elastomer and also have a hole which is actively connected to the threaded bolt 28. For example, a rubber material or another elastically deformable plastics material or mixtures thereof can be used as the elastomer. A locking nut 29 is detachably connected to the threaded bolt 28 in the axial direction thereof, next to the second disc 27.
For a more even distribution of the load over the system length L of the crossbeam 1 or on the upper chord 2, the connection elements 6 can be configured with a respective damping element 25 to 27. With the same geometric dimensions on the respective damping element 25 to 27, specifically the damping material 26 for each individual damping element 25 to 27 or for the connection element 6 can have different moduli of elasticity (elastic modulus). The higher the respective elastic modulus of a damping material 26, the more rigid the connection between connection element 6 and anchor rail 14 and vice versa. Thus, by considering the elastic moduli, with the same geometric dimensions on the suspension points A or connection elements 6, a more even distribution of the load can be achieved over the system length L of the crossbeam 1 or on the upper chord 2. Due to the damping elements 25-27, the reaction forces on the connection elements 6 (viewed over the system length L) of the crossbeam 1 can be distributed more evenly.
The mode of operation according to FIGS. 5 and 6 is as follows. The crossbeam 1 with a linear upper chord 2 and a lower chord 3 arranged adjacently at a distance therefrom, as well as a plurality of webs 4 connecting the upper chord 2 and the lower chord 3 in a material-uniting manner comprises the lower chord 3 in a state without a live load F in a parallel arrangement to the upper chord 2 or with a convex curvature directed towards the upper chord 2. The upper chord 2 is detachably connected by connection elements 6 to the supporting construction 15, alternatively to the anchor rail 14 (Halfen channel) arranged on the supporting construction 15 at each end face by a respective transmission mechanism 21, 23, 24 or 21 to 24 via the respectively associated plate 24. Thereafter, a live load F can be applied to at least one hold point (lower chord 3) with a sling gear 7. In this respect, in the first configuration, the lower chord 3 remains substantially parallel, i.e. it remains linear with respect to the upper chord 2. In the second configuration, the originally convex, pretensioned curved shape of the lower chord 3 is altered as a result of the active live load F and it changes into a linear configuration form of the lower chord 3.
To avoid overloading or to prevent the safety of the crossbeam 1 from being compromised, the maximum live load F is to be established for each crossbeam 1. The hold point of the sling gear 7 can be arranged on a straight line, in the present example on the vertical, to the apex S of the convex curvature. If the live load F on the sling gear 7 is removed, the linear configuration form of the lower chord 3 changes back into the convex curved form (second configuration).
The illustration of the convex curvature of the lower chord 3 in FIGS. 1 and 2 is shown in this form merely to provide a clearer understanding and thus is not true to scale.
The connection elements 6 can connect the respective crossbeam 1 to the supporting construction 15 or to the anchor rail 14 with a defined torque. Under a safety aspect, the respective defined torques can be detected by data and documented.
The working method comprises a method for mounting a crossbeam 1 on a supporting construction 15, alternatively on an anchor rail 14 arranged thereon, the crossbeam 1 being formed by an upper chord 2 and a lower chord 3 and by a plurality of webs 4 connecting the upper chord 2 and the lower chord 3, characterised in that a plurality of suspension points A are provided at intervals on the upper chord 2, in that a respective connection element 6 is then arranged on the upper chord 2 at each suspension point A and in that each connection element 6 is then detachably connected to the supporting construction 15 or to the anchor rail 14. In this respect, the suspension points A and thereby the connection elements 6 can be provided on the upper chord 2 in the same intervals from one another. In a further step, a crossbeam 1 can be detachably connected to a further structurally identical crossbeam 1′, strung together by coupling elements 16. In this respect, the crossbeam 1′ is connected to the supporting construction 15 or to the/an anchor rail 14 arranged on the supporting construction 15 at the suspension points A by the connection elements 6 analogously to the crossbeam 1.
Alternatively, at least one anchor rail 14 is arranged in a fixed manner on the supporting construction 15 and the connection elements 6 of the crossbeam, 1, 1′ are detachably connected to the anchor rail 14.
Alternatively, the upper chord 2 can be detachably connected by connection elements 6 to the supporting construction 15, alternatively to the anchor rail 14 (Halfen channel) arranged on the supporting construction 15 at each end face by a respective transmission mechanism 21, 23, 24 or 21 to 24 via the respectively associated plate 24. In this configuration, the end faces of the upper chord form the suspension points of the crossbeam 1. Thereafter, a live load F can be applied to at least one hold point (lower chord 3) with a sling gear 7. In this respect, in the first configuration, the lower chord 3 remains substantially parallel, i.e. it remains linear with respect to the upper chord 2. In the second configuration, the originally convex, pretensioned curved shape of the lower chord 3 is altered as a result of the active live load F and it changes into a linear configuration form of the lower chord 3.
In the configuration in which a respective suspension point A is provided on the end faces of the upper chord 2, each suspension point A is detachably connected by connection elements 6 to the supporting construction 15 or to the anchor rail 14 by means of a respective transmission mechanism 21, 23, 24; or 21 to 24, comprising a plate 24.
While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

LIST OF REFERENCE NUMERALS

1 crossbeam
2 upper chord
3 lower chord
4 web
5 clearance
6 connection element
7 sling gear
8 circular arc
9 reinforcing plate
10 outer side (upper chord)
11 outer side (lower chord)
12 inner side (upper chord)
13 inner side (lower chord)
14 anchor rail
15 supporting construction
16 coupling element
17 load cell
18 display/evaluation means
19 half clamps
20 hole
21 first fixed joint (upper chord)
22 coupling rod
23 second fixed joint (plate)
24 plate
25 first disc
26 damping material
27 second disc
28 threaded bolt
29 locking nut
A suspension point
A_Oaxis of upper chord
A_Saxis of web
A_Uaxis of lower chord
E₁first end point
E₂second end point
F live load
H system height
L system length
S apex
x deflection

Claims

What is claimed is:

1. A crossbeam comprising:

a linear upper chord disposed along an upper chord axis and comprising a plurality of suspension points arranged at intervals;

a lower chord disposed along a lower chord axis adjacently at a distance from the upper chord, the lower chord axis being in alignment with the upper chord axis, and the lower chord being parallel to the upper chord or having a convex configuration when no live load is applied;

a plurality of webs connecting the upper chord and the lower chord by welded constructions, the webs being each disposed along a respective web axis that intersects the upper chord axis and the lower chord axis; and

a connection element disposed on the upper chord at each suspension point.

2. The crossbeam as recited in claim 1, wherein the connection elements are detachably connected to a fixed anchor rail that is connected to a supporting construction.

3. The crossbeam as recited in claim 1, wherein the connection elements are disposed on the upper chord at identical intervals from one another.

4. The crossbeam as recited in claim 1 further comprising at least one clearance disposed between the upper chord and the lower chord, and at least one clearance between the webs.

5. The crossbeam as recited in claim 4, wherein the connection elements are disposed in a region of the at least one clearance.

6. The crossbeam as recited in claim 1, further comprising a reinforcing plate disposed between the upper chord, the lower chord, and each adjacent web connected by welded construction, the reinforcing plate connecting to the an inner side of the upper chord and an inner side of the lower chord.

7. The crossbeam as recited in claim 1, wherein the lower chord includes the convex configuration and has a convex curvature including a circular arc having an apex disposed centrally with respect to a system length of the crossbeam.

8. The crossbeam as recited in claim 7, wherein the circular arc is delimited by a first end point and a second end point, a maximum distance between the first end point and the second end point corresponding to a system length of the crossbeam.

9. The crossbeam as recited in claim 1, wherein a damping element is actively connected to each connection element on an inner side of the upper chord.

10. A crossbeam comprising:

a linear upper chord disposed along an upper chord axis, the upper chord including at least one free end face;

at least one transmission mechanism rigidly connected to the at least one free end face of the upper chord, the at least one transmission mechanism comprising a plate detachably connected to a supporting construction by connection elements.

11. The crossbeam as recited in claim 10, wherein the crossbeam includes at least one of a steel or an aluminum alloy, and the webs are aligned with respect to the upper chord and the lower chord at least one of perpendicularly or diagonally.

12. The crossbeam as recited in claim 1 further comprising coupling elements at one end of both the upper chord and the lower chord for detachably connecting a further structurally identical crossbeam.

13. A method for mounting a crossbeam on a supporting construction, the method comprising:

providing a crossbeam comprising an upper chord, a lower chord, a plurality of webs connecting the upper chord and the lower chord, and a plurality of suspension points disposed at intervals along the upper chord;

disposing a connection element on the upper chord at each suspension point; and

detachably connecting each connection element to the supporting construction.

14. The method as recited in claim 13, wherein a suspension point is disposed on an end face of the upper chord, and each suspension point is detachably connected to the supporting construction by the connection elements via a transmission mechanism comprising a plate.

15. The method as recited in claim 13 further comprising detachably connecting the crossbeam to a further structurally identical crossbeam.

16. The method as recited in claim 13 further comprising fixing an anchor rail on the supporting construction and detachably connecting the connection elements to the anchor rail.