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.
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.
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.
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.
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:
a shows the relative position of the axes along sectional line A-A in
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
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 (
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
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′ (
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
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.
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
According to
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
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
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
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
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.
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
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
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.
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
AO axis of upper chord
AS axis of web
AU axis of lower chord
E1 first end point
E2 second end point
F live load
H system height
L system length
S apex
x deflection
Number | Date | Country | Kind |
---|---|---|---|
10 2013 005 275.0 | Mar 2013 | DE | national |
10 2014 002 666.3 | Feb 2014 | DE | national |