CONNECTING DEVICE FOR CONNECTING BOOM SEGMENTS OF A BOOM OF A TOWER CRANE

Description

Technical field

[0001] The present invention relates to a jib of a tower crane, in particular a jib in the form of a crane element known in the trade as a trolley jib or trolley boom. The invention further relates to bottom chord connections for connecting jib segments for such a jib. Technical background

[0002] The booms of tower cranes generally consist of individual boom segments that are detachably connected by means of connecting devices. Such booms, among other structural features, have at least one bottom chord and at least one top chord. Bottom chords are preferably made of square-section steel tubes, while top chords are made of flat steel, square-section steel tubes, or round-section steel tubes. The top chord primarily serves to absorb forces resulting from tensile loads and is located at the top of a boom segment. The bottom chord primarily serves to absorb forces resulting from compressive loads and is located at the base of a boom segment. The boom segments have connecting devices in the areas where they are joined.These connecting devices form the end face termination of the at least one upper chord or the at least one lower chord for the boom segment in question.

[0003] Certain designs of tower crane jibs are called trolley jibs or trolley travel jibs because they include a track and a lateral guide for a deflection device for a lifting rope, which is referred to in technical circles as a trolley or cat.

[0004] Such booms can also be used within steel structures, e.g. in mobile steel hall or fixed hall construction, or with booms of other crane types, such as mobile port cranes or semi-stationary storage yard cranes, insofar as such steel structures or crane booms have steel structure or boom segments connected by means of a connecting device, which are based on a truss or grid structure.

[0005] The individual boom segments of a tower crane jib are typically connected, or assembled, on the ground before the crane is put into operation. In exceptional cases, boom segments are added to the jib of an already operational tower crane using detachable connection techniques to extend it. Detachable connections must therefore be suitable for both installation scenarios and be designed accordingly.

[0006] The connection techniques used to construct such a boom from boom segments generally comprise a few easy-to-handle, maintenance-free, backlash-free, and low-wear connecting elements.

[0007] A jib of a tower crane is known, for example, from EP 1 728 756 B1. This jib features a connecting device formed of pins and centering pins between two jib elements, separate recesses for receiving these pins and centering pins, and fixing elements that, in operative connection with each other and with each other, fix the jib segments to one another and detachably connect them. In technical circles, this connecting device is also known as Liebherr LiConnect (see "LIEBHERR ECB LiConnect", website brochure p. 18). A primary disadvantage of such a connecting device for the lower chords of jib segments is that, due to its arrangement, the device can only absorb the forces over the limited area of ​​the end faces of the lower chords.The crossbeams of the ECB boom, located between the lower chords at the base, do not transmit any forces within the end-face connection area of ​​the segments because these crossbeams are not directly connected to each other in the steel structure at this connection point; in other words, they are not mechanically coupled directly to one another. Consequently, the wear pattern of a connection device implemented using the LiConnect concept is pronounced because the transmitted forces are introduced exclusively in a limited area via the end-face surfaces located outside the pin. The resulting load-bearing pattern is characterized by extremely high local forces and the corresponding stress peaks.

[0008] Furthermore, the lateral forces and resulting moments generated by the rotation of the tower crane at the base of the jib cannot be fully absorbed by such a connection device, and local counter-moments, particularly by the pivot, can be generated. This can lead to permanent, incremental deformations of the jib segment at its base, and especially of the connection device. Therefore, the jib structure must be constructed of solid steel in the lower chords and where these are integrated into the truss structure of the jib segment. In this context, the relatively complex design of the connection device, particularly in the area of ​​the end faces of the lower chords (so-called...), should be mentioned as a further disadvantage.The joints (and the pin's mounting) as well as the pin itself are designed to achieve a so-called tight fit, meaning a permanent positive connection between the connecting elements and thus between the joints. Despite this considerable structural engineering effort, opening of the joints during crane operation cannot be permanently prevented. Furthermore, the pin wears within its mounting due to friction and dynamic bearing play, which cannot be subsequently adjusted or compensated for. Therefore, the tolerances of both the mounting and the pin must be tightly designed from the outset.

[0009] From EP 1 468 955 A1, a tower crane boom is known in which the end plates of the lower chords are designed as crossbeams and extend transversely to the boom's longitudinal axis. The crossbeams have round cutouts (bores), a first of which accommodates a clamping bolt secured by a wedge. The wedge, which is not fixed in position, is secured against slipping out by a locking pin (spring pin). A second round cutout (bore) in the crossbeams accommodates a centering bolt in the end face of the lower chords. Within the end faces of the lower chords, centering bolts are mounted on the crossbeam of one lower chord to be joined, which engage complementarily in round cutouts of the end faces of the crossbeam of another lower chord to be joined.These centering bolts are designed as cylinders with a stepped section and two immediately consecutive, conically shaped areas with different flank slopes, with the cylindrical part within the end face functioning as a sealing section.

[0010] The detachable connection between the lower chords is represented by a locking unit consisting of several links. The locking unit is located in close proximity to, but spaced apart from, the respective end-face centering pin. Each connection unit comprises a clamping pin that is slidably mounted along a slide welded to the crossbeam in the longitudinal direction of the boom segment, parallel to the lower chord. The connection between the lower chords is achieved by sliding the clamping pin along the slide into the circular cutout in the end-face crossbeam of the other boom section and inserting a locking wedge into the head of the clamping pin. A primary disadvantage of this type of connection device for boom sections is that the connection unit is only inadequately able to absorb the forces and moments that occur.A further disadvantage is that the end crossbeams located between the bottom chords at the base can only absorb forces locally and to a limited extent within the end-face connection area of ​​the segments, because these end crossbeams are not directly coupled to each other over a large area in the steel structure connection area. Due to their spacing relative to the end face of the bottom chords, the connection device primarily absorbs axial bending moments and only to a small degree shear forces, without being able to generate corresponding bearing forces or counter-moments. The forces acting on the bottom chord connection are distributed between the points of end-face fixing and the points of connection, which in turn results in greater structural steelwork complexity in order to absorb these redirected forces without deformation of the base-face cantilever area and the connecting elements.Another disadvantage is the relatively complex design of this connecting device, which has many elements that need to be secured against loss.

[0011] US 7 156 245 B2 discloses the preamble of claim 1.

[0012] The object of the present invention is to further develop a detachable connection of boom segments in such a way that it is, on the one hand, composed of few elements and simple in construction, and on the other hand, suitable for absorbing large forces as well as moments acting on the boom elements during crane operation. Ideally, the forces and moments that change during crane operation should be counteracted by generating local, adjustable bearing forces and counter-moments. Disclosure of the invention

[0013] This problem is solved by a connecting device for a boom segment having the features of claim 1 and the dependent claims.

[0014] Further details are specified in the dependent claims.

[0015] According to a first aspect, a bottom chord connection with a connecting device, in particular for connecting boom segments of a tower crane boom, is provided, comprising: at least one connecting bolt with a first fastening part for attachment to a first pressure plate of a first boom segment and with a second fastening part for attachment to a second pressure plate of a second boom segment, wherein the first fastening part is provided with a releasable, rotationally secure connecting device for attachment to the first pressure plate, wherein the second fastening part is provided with a centering mandrel for attachment to the second pressure plate, which has a radial, in particular continuous, locking groove for receiving a plug wedge; at least one centering sleeve for insertion into a corresponding through-hole in the second pressure plate, which has an inner cross-section to receive the second fastening part in a form-fitting manner.

[0016] In particular, the first through-hole in the first pressure plate, which may be present at least once, can be designed to receive the connecting bolt in a form-fitting manner, especially in the axial and radial directions of the through-hole. In particular, the through-hole in the second pressure plate can be designed to receive the centering sleeve in a form-fitting and friction-fit manner in the axial and radial directions of the through-hole in the second pressure plate.

[0017] Consequently, the connection device according to the invention is characterized in particular by the fact that its elements advantageously combine the function of a fixed screw connection with the function of a detachable plug connection by means of adjustable centering and fixing elements.

[0018] The proposed connection device primarily uses standard parts with a few special parts in operative connection, thereby achieving a high degree of standardization and predictability in the design of the individual elements and ultimately a high functional reliability of the boom.

[0019] To increase stiffness in the lower chord area, it has proven advantageous to connect the lower chords of the boom segment to each other at their ends, preferably via at least two compression plates. By creating a flat contact between the at least two compression plates, which close off the end faces of the boom segments at their bases, these plates function as two mechanically connected crossbeams. The lower chords are then structurally restrained by these crossbeams, which can have the same external geometry and thus double the cross-sections that absorb forces and moments at the base of the boom segments. This stiffens the boom segment structure in an area where maximum bending and shear forces and moments act on the lower chords.

[0020] The pressure plates integrated into the end face foot area of ​​the boom segment thus create a maximally effective transmission surface, through which the connection between the lower chord areas of two boom segments is established and which is not only located in the limited area of ​​the surfaces directly in the area of ​​the end faces of the lower chords, but over a maximum end face foot area that extends in a plane that forms transversely or at an angle to the longitudinal axis of the boom.

[0021] Furthermore, it is advantageous if the connecting device comprises at least one preferably one-piece and rotationally symmetrical connecting bolt, a first through-opening located in a first pressure plate and receiving the connecting bolt, a centering sleeve arranged between the connecting bolt and a second through-opening of a second pressure plate, and a plug-in wedge.

[0022] The elements of the connecting device, mounted on the boom segments to be joined, complement each other. A first boom segment has a first pressure plate in the foot area of ​​its end face. This first pressure plate accommodates the connecting device, which connects a second pressure plate located in a second boom segment to be joined. The first and second pressure plates connected by the connecting device are primarily in contact with each other; any frictional engagement between the first and second pressure plates can be neglected when determining the connecting forces generated between the boom segments by the connecting device.

[0023] The first fastening element may have a second cylindrical surface section, which in particular adjoins the second fastening element directly. Specifically, the first fastening element may have a threaded section adjoining the second cylindrical surface section in order to fasten the first fastening element to the first pressure plate by screwing it in. The second cylindrical surface section may be provided with an anti-rotation device, which in particular is formed by a centering pin projecting from the second cylindrical surface section.

[0024] To accommodate multiple connecting bolts in a parallel manner according to a preferred embodiment of the connecting device, it has proven advantageous for the first pressure plate to have several first through-holes and the second pressure plate to have several corresponding second through-holes. Parallel accommodation then refers to the identical (preferably parallel with respect to their longitudinal directions) orientation of the mounted connecting bolts, such that the connecting bolts located in and on the pressure plates point in the same direction.

[0025] It may be provided that at least one further connecting bolt is provided with a first fastening part for attachment to the second pressure plate of the second boom segment and with a second fastening part for attachment to the first pressure plate of the first boom segment, wherein the first fastening part is provided with a detachable connecting device for attachment to the second pressure plate, wherein the second fastening part is provided with a centering mandrel for attachment to the first pressure plate, which has a radial, in particular continuous, locking groove for receiving a plug-in wedge, and a centering sleeve for insertion into a corresponding through-hole in the first pressure plate is provided, which has an inner cross-section to receive the second fastening part in a form-fitting manner.

[0026] To accommodate multiple connecting bolts in an alternating manner, as in a further conceivable embodiment of the connecting device, it has proven advantageous for both the first and second pressure plates to each have at least one first through-hole and at least one second through-hole. Alternating accommodation refers to the orientation of the connecting bolts such that at least two of the connecting bolts located in and on the pressure plates point in opposite directions.

[0027] The at least one first through-hole can be widened in its upper region by means of a groove to accommodate a centering pin, which advantageously secures the connecting bolt against rotation during its tightening to the pressure plate. This ensures that the insertion of the wedge into a locking groove located in the head of the connecting bolt can always be carried out vertically from above, which is advantageous for ground-level assembly of the boom segments on the construction site and especially for assembly of the boom segments during crane operation, sometimes at considerable heights. The connecting bolt is provided at one end with a first section (screw thread section, characterized by a first cross-section), in particular with a metric thread of normal pitch.

[0028] A second section of the connecting bolt has a first shoulder immediately following the first section (threaded section), from which the first cross-section of the connecting bolt widens into a second cross-section. The first and second sections form the first fastening part of the connecting bolt. A first contact surface is formed between the first and second cross-sections of the connecting bolt. This surface may also be non-circular and has a first chamfer in its upper region. This chamfer facilitates the insertion of the connecting bolt into the at least one first through-hole of the first pressure plate, which is particularly advantageous for the assembly of the connecting bolt.

[0029] The second section (second cylindrical surface section) of the connecting bolt is characterized by a first cylindrical surface in which a bore for receiving a centering pin is recessed. This centering pin is received in a groove when the connecting bolt is threaded in; this groove, extending from the first through-hole of the first pressure plate (which has at least one), serves to radially fix the connecting bolt.

[0030] During assembly, the first and second sections of the connecting bolt are inserted into at least one through-hole in the first pressure plate. A locking washer is placed on the threaded portion of the first section protruding from the mounting side of the first pressure plate, ensuring that a castellated nut screwed onto the threaded section sits flush against the mounting side of the first pressure plate. This advantageously results in a uniform and predictable distribution of the tightening forces across a large cross-section of the mounting side of the first pressure plate.

[0031] The lateral surface of the second section of the connecting bolt ends at a second shoulder and, through its full-surface contact in the at least one first through-opening of the first pressure plate, ensures on the one hand a radial fixation of the connecting bolt in the first pressure plate and on the other hand a low-play connection between the connecting bolt and the first pressure plate.

[0032] Starting with the second section, a third section (first cylindrical surface section) of the connecting bolt extends, from which the second cross-section of the connecting bolt widens into a third cross-section. A second contact surface is formed between the second and third cross-sections of the connecting bolt, which rests directly against the end face of the first pressure plate. This second contact surface ensures both axial contact of the connecting bolt and the transmission of the axial preload forces generated by the connecting bolt to the end face of the first pressure plate.

[0033] The third section (first cylindrical surface section) of the connecting bolt is characterized by a second cylindrical surface. This surface transitions into a fourth section of the connecting bolt, which is referred to as the head. The third and fourth sections together form the second fastening part of the connecting bolt.

[0034] Furthermore, the connecting bolt can have a section in its head area that tapers towards the second fastening part and connects to a first cylindrical shell surface section, wherein the first cylindrical shell surface section can be received in the centering sleeve in a mounted state, in particular by positive locking.

[0035] The tapered section located in the head region of the connecting bolt can be characterized by a third surface, which is designed as a cone and thus forms a centering pin. The centering pin terminates in a second chamfer, which simultaneously forms the other end of the connecting bolt.

[0036] The second chamfer, together with the conical surface of the connecting bolt's centering mandrel, facilitates the insertion of the connecting bolt and the centering sleeve into the at least one second through-hole of the second pressure plate. This significantly simplifies the assembly of boom segments to be connected, which particularly benefits their safe handling and assembly.

[0037] A further advantage of the novel connecting device for a bottom chord connection is provided in particular by the introduction of a centering sleeve. The centering sleeve can be designed with a fully or partially circumferential flange, which may be located at an axial end of the sleeve and, in the assembled state, is positioned in the direction of the second fastening element. This centering sleeve can thus be designed as a collar-type bushing and is characterized by a first sleeve section that has the shape of a tube, which need not necessarily be round, and comprises an inner wall and an outer wall with an intermediate surface, which need not necessarily be an annular surface.At a first end of the first sleeve section, a chamfer can be arranged between the surface and the inner wall, which, as an insertion aid complementary to the cone of the centering mandrel of the connecting bolt, facilitates the insertion of the centering sleeve onto the second outer surface of the connecting bolt.

[0038] At the second end of the first sleeve section of the centering sleeve is a relief groove to which a second sleeve section of the centering sleeve is attached. This second sleeve section is characterized by a circumferential flange with an inner and outer flange surface. The flange surfaces thus have a first and a second bearing surface as well as an inner diameter and an outer diameter, giving this second sleeve section the shape of a collar. This collar is cut off on one side at the outer cross-section, which allows for greater flexibility in the structural steel design of the cantilever segment.

[0039] As previously described, the centering sleeve is positioned between the cylindrical surface of the first section of the connecting bolt and the wall of at least one second through-hole located in the second pressure plate. The centering sleeve is dimensioned axially and radially to provide a maximum contact area, ensuring full-surface contact for both the second cylindrical surface of the connecting bolt and the wall of the second through-hole in the second pressure plate. A relief groove between the first and second sections of the centering sleeve, with an inwardly directed radius, creates a smooth, step-free contact surface.

[0040] Both the centering sleeve and the at least one second through-hole of the second pressure plate can be designed with cross-sections and diameters such that, in combination, they provide a clearance fit. This ensures, on the one hand, optimal transmission of the radial forces acting on the centering mandrel and, on the other hand, the absorption of the moments acting on the length of the centering mandrel clamped in the second pressure plate. When manufacturing the centering sleeve as a turned part, tight tolerances should be applied to the dimensions of the outer wall of the first sleeve section to minimize clearance between it and the wall of the at least one second through-hole in its installed position.

[0041] A further advantage of the connecting device lies particularly in the axial force input via the engaged inner and outer contact surfaces of the centering sleeve in the second sleeve section. This ensures that the axial preload generated by the centering mandrel and the wedge results in uniform and maximum surface pressure between the first and second pressure plates. In conjunction with the rigid centering bolt, the elastic centering sleeve and the elastic pressure plates provide improved bending, shear force, and moment absorption, as well as optimized resilience of the connecting device.

[0042] A further advantage of the centering sleeve can lie, in particular, in its design with a fully or partially circumferential flange, which, as previously described, can be designed as a collar. The collar located in the second sleeve section is characterized, in particular, by an inner and outer flange surface. The bearing surface formed between the inner and outer diameters of the collar can be designed depending on the area and thus the area-related resistance of the first and second pressure plates. Due to its radial and planar contact in the first and second sleeve sections, the centering sleeve ensures a large-area introduction and uniform distribution of the axial and radial preload forces into the second and / or first pressure plate. These preload forces are generated by the clamping of the wedge within the locking groove of the centering mandrel.By allowing adjustment of the outer cross-section of the centering sleeve in the second sleeve section, i.e., the collar or its flange, it is advantageous to create, on the one hand, a maximized inner flange area for the full-surface contact of the centering sleeve with the mounting side of the second and / or first pressure plate, and on the other hand, the largest possible outer flange area for the full-surface contact of a second contact surface of the wedge.

[0043] Furthermore, it may be provided that the flange of the centering sleeve is equipped with one or more fastening devices for rotationally secure attachment to the first and / or second pressure plate.

[0044] A wedge serves to secure the connection device. This wedge is inserted, preferably from above, into a locking groove located in the conical centering mandrel of the connecting bolt. The wedge can be made in different lengths, allowing its contact surface to be adapted to the outer flange surface of the second sleeve section of the centering sleeve.

[0045] Another advantage of the connecting device is its adjustability. This adjustability is achieved primarily through the wedge, which can be moved to a limited extent.

[0046] After the connecting bolt has been pushed through the at least one second through-hole in the second pressure plate and after the centering sleeve has been inserted, the wedge is inserted into the continuous locking groove located in the conical area of ​​the centering mandrel of the connecting bolt in the space formed between the second outer surface of the connecting bolt and the wall of the at least one second through-hole.

[0047] The wedge is solid and can have different outer contours on its respective contact surfaces. The outer contour of a first contact surface forms the head end and absorbs the clamping forces, preferably applied by hammer blows, during assembly of the connecting device. The outer contour of a second contact surface rests directly against the outer flange surface of the centering sleeve when the connecting device is assembled and transmits axial and radial clamping forces to it via positive locking. The outer contour of a third contact surface can have a rounded shape. This rounded outer contour allows the third contact surface of the wedge to make full contact with the outer wall of the locking groove of the centering mandrel, thereby creating maximum clamping of the wedge within the centering mandrel.

[0048] This third contact surface can form an angle with respect to the second contact surface and causes the wedge to be wedged against the inner and outer walls of the locking groove within the locking groove of the connecting bolt.

[0049] The wedge, when installed, can be secured against upward movement by a locking pin, which may be a spring-loaded pin (standard part). Depending on the insertion depth of the wedge within the locking groove, the locking pin can be inserted into at least one locking hole located in the lower leg of the wedge to secure it in its respective position within the locking groove. This ensures permanent fixation of the wedge and thus guarantees sufficient clamping forces, both within the locking groove of the connecting bolt and against the outer contact surface of the centering sleeve, and therefore against the mounting side of the first and / or second pressure plate.

[0050] Depending on the wear of the lower chord connection, which depends on the operating time of the crane and the associated deformations of the individual boom segments, the strength of the lower chord connection can be maintained permanently at a high level by the wedge slipping due to its own weight or by mechanically resetting the wedge, especially by means of hammer blows.

[0051] In the lower chord connection, the connecting device can be modeled on a fixed bearing. According to a further aspect, it has proven advantageous in a preferred embodiment to relieve the load on the inventive connecting device, in its fixed bearing configuration, by means of a further cantilever connection. This further cantilever connection can be formed by an additionally introduced fixing device, which, complementary to the fixed bearing of the connecting device, can be designed as a floating bearing. Here, the fixed bearing can be located outside the end face of the lower chords. The floating bearing can be arranged at or within the end face of the lower chords. The end faces of the lower chords are understood to be the contact surfaces that form directly in the joints above the ends of the lower chord tubes, transverse to the longitudinal axis of the cantilever.Through the interaction of the fixed bearing and the sliding bearing, the lower chords of two boom segments to be joined, and in particular the joints above the ends of the lower chord tubes, are fixed in position relative to each other and to each other, and are permanently and releasably connected to each other by means of adjustable connecting forces.

[0052] A movable trolley can be arranged along the lower chord. During crane operation, loads suspended from the trolley can exert a maximum bending moment on the compression plates at the end faces of the lower chords (jib chords) as the trolley travels over the jib joints. This can lead to permanent, localized deformation of the end faces of the jib joints, resulting in the formation of at least one step between opposing and adjacent jib joints. Since the lower chords typically have running surfaces for the trolley, such steps can cause mechanical impacts during trolley travel under load.

[0053] According to another aspect, the above lower chord connection is provided with the connecting device, wherein the lower chord connection connects two lower chords of the boom segments, i.e., a lower chord of the first boom segment and a corresponding lower chord of the second boom segment, wherein a fixing device is provided at the end face of each pair of lower chords to secure the lower chords against displacement transverse to their axial direction.

[0054] It has therefore proven advantageous if an additional fixing device, inserted in the highly stressed lower chord area of ​​the pressure plate, can support the centering effect of the connecting device. This local support provided by the fixing device leads to additional relief of the connecting device and to a durable and low-wear fixing of the lower chords to each other and to one another in the area of ​​the joints, which are located in the immediate vicinity above the end faces of the lower chord tubes. The fixing device can, in particular, be arranged centrally in the surfaces of the end faces, i.e., the joints of the lower chords. Other arrangements of the fixing device within the lower chord connection are conceivable, for example, in an area above, below, or laterally to the structural center of the respective lower chord.

[0055] Furthermore, the fixing device may include: at least one screw mandrel with a first fastening section for attachment to the first pressure plate and with a second fastening section for attachment to the second pressure plate, wherein the second fastening section has a cylindrical surface section for fastening the screw mandrel to the second pressure plate, wherein a bushing is provided for insertion into a through-hole in the second pressure plate, wherein the bushing has an inner wall to receive the cylindrical surface section of the second fastening section in the through-hole.

[0056] Furthermore, the first fastening section can be provided with a threaded section for fastening the screw mandrel to a threaded bore in the first pressure plate.

[0057] It may be provided that the lateral surface section of the second fastening section is received in the through-opening in a form-fit and friction-fit manner.

[0058] Thus, in addition to the connecting device according to the invention, at least one further fixing device can be provided, comprising: at least one screw mandrel with a first fastening section for fastening to a first pressure plate of a first boom segment and with a second fastening section for fastening to a second pressure plate of a second boom segment, wherein the first fastening section is provided with a threaded section for fastening the screw mandrel to a threaded bore in the first pressure plate, wherein the second fastening section has a cylindrical surface section for fastening the screw mandrel to the second pressure plate, at least one bushing for insertion into a corresponding through-hole, wherein the through-hole is located in the second pressure plate, wherein the bushing has an inner wall to receive the cylindrical surface section of the second fastening section in a form-fit and friction-fit manner.

[0059] A further advantage of the novel lower chord connection is thus provided in particular by the introduction of an additional fixing device. The elements of the fixing device, mounted on the boom segments to be joined, complement each other. To this end, a first boom segment has a first pressure plate in the foot area of ​​its end face. This first pressure plate accommodates the previously described connection device as well as the fixing connection, by means of which a second pressure plate located in a second boom segment to be joined is connected.The first and second pressure plates, connected by the connecting device and the fixing device, are predominantly in positive contact and fully against each other; any frictional connection between the first and second pressure plates can be neglected when determining the connecting forces generated between the boom segments by means of the connecting device and the fixing device.

[0060] Furthermore, it is advantageous if the at least one fixing device comprises a preferably one-piece and rotationally symmetrical screw mandrel with a first and a second fastening section, a threaded bore located in a first pressure plate and receiving the first fastening section, a further through-hole located in the second pressure plate and receiving the second fastening section, and a bushing arranged between the second fastening section and the further through-hole. It can be provided that the first fastening section of the fixing device has a threaded section that directly adjoins a preferably cylindrically shaped circumferential surface section of the second fastening section of the fixing device.In particular, the first fastening section can be secured by screwing it into a threaded bore in the first pressure plate using the threaded section. The second fastening section of the fixing device can comprise a cylindrical surface section and a head section, wherein the cylindrical surface section can, in particular, have a cylindrical shape and the head section can, in particular, have a hexagonal profile. It is also conceivable that the cylindrical surface section and the head section can have a polygonal shape, for example, a triangular, square, or pentagonal shape. A chamfer can be formed between the head section and the cylindrical surface section of the second fastening section. The chamfer can facilitate the insertion of the cylindrical surface section of the second fastening section into a bushing with a complementary geometric design.

[0061] The fixing device can include a bushing, which can be arranged within a corresponding through-opening in a second pressure plate. This through-opening can, in particular, be designed as a bore, which can, in particular, have a round profile. The bushing can, in particular, be designed as a replaceable bushing and can, in particular, have the form of a tube, which need not necessarily be round, and has an inner wall and an outer wall with an intermediate surface, which need not necessarily be annular. At a first end of the bushing, a chamfer can be arranged between the surface and the inner wall, which serves as an insertion aid complementary to the chamfer of the screw mandrel and facilitates the threading of the mandrel's outer surface during assembly.A second end of the bushing can be positioned directly in front of a stiffening plate, where it engages with a stop. This stop secures the bushing in its longitudinal direction against migration into the rear area of ​​the bottom chord. The stiffening plate, acting like a bulkhead, serves two purposes: firstly, to stiffen the bottom chord in the area where two bottom chords connect, and secondly, to seal the bottom chord against water ingress and the resulting corrosion of its rear area.

[0062] To accommodate several centering mandrels and several screw mandrels in a parallel orientation according to a preferred embodiment, it has proven advantageous for the first pressure plate to have several first through-holes and the second pressure plate to have several second through-holes corresponding to the first through-holes, as well as a further through-hole. Parallel mounting is then understood to mean the identical (preferably parallel with respect to their longitudinal directions) orientation of the mounted connecting bolts and screw mandrels, such that the connecting bolts and screw mandrels located in and on the pressure plates point in the same direction.

[0063] It can therefore be provided that at least one further screw mandrel is provided with the first fastening section for fastening to the second pressure plate of the second boom segment and with the second fastening section for fastening to the first pressure plate of the first boom segment, wherein the first fastening section of the further screw mandrel is provided in particular with a metric thread of normal pitch for fastening to the first pressure plate, wherein the second fastening section of the further screw mandrel is provided with a cylindrical surface section for releasable fastening in a further through-hole in the second pressure plate, and a bushing is provided for insertion into the further through-hole in the second pressure plate, which has an internal cross-section with a corresponding shape to receive the cylindrical surface section of the second fastening section of the screw mandrel in a form-fit and friction-fit manner. Brief description of the drawings

[0064] Further details of the invention are explained in more detail with reference to an embodiment illustrated in the accompanying drawings. Multiple references to a component in one and the same figure include both the singular and plural forms of the respective element depicted. These include: Figures 1a, 1b are perspective overview views of end-view embodiments of the tower crane jib segment in the unassembled state; Figures 2a, 2b, 2c are perspective overview views of the base area of ​​two jib segments connected by means of the bottom chord connection according to one embodiment; Figure 2a is a perspective overview view of the base area of ​​two jib segments connected by means of the bottom chord connection according to another embodiment; Figures 3a, 3b are perspective views of pressure plates according to one embodiment, wherein the pressure plates are shown individually from the truss or grid structure of the jib segment; Figure 3c is a side view and perspective view of a pressure plate according to another embodiment, wherein the pressure plate is shown individually from the truss or grid structure of the jib segment;Figure 4 shows a perspective overview view of elements of the bottom chord connection (exploded view), as well as two pressure plates to be connected; Figure 5a shows a perspective view of the elements of the bottom chord connection according to a preferred embodiment, as well as the pressure plates of a preferred embodiment connected by means of the bottom chord connection; Figure 5b shows a perspective view of the elements of the bottom chord connection according to a further embodiment, as well as the pressure plates of a further embodiment connected by means of the bottom chord connection; Figure 6 shows a view of the assembled elements of the bottom chord connection, as well as the bottom chords and the pressure plates in section; Figure 7 shows a side and perspective view of the connecting bolt; Figure 8 shows a side and perspective view of the centering sleeve; and Figure 9 shows a perspective view of the plug wedge;Figures 10a and 10b are perspective overview views of the end faces of preferred embodiments of the tower crane boom segment in the unassembled state; Figure 11a shows a section view of the base area of ​​two boom segments connected by means of the connecting device and the fixing device according to a preferred embodiment; Figure 11 shows a section view of the assembled elements of the fixing device and the connecting device according to a preferred embodiment of the bottom chord connection, as well as the bottom chords and the pressure plates; Figure 12 shows a section view of the assembled elements of the fixing device according to a preferred embodiment of the bottom chord connection, as well as the bottom chords and the pressure plates;Figures 13a and 13b show perspective views of pressure plates according to a preferred embodiment of the lower chord connection, wherein the pressure plates are shown in individual perspectives isolated from the truss or grid structure of the cantilever segment. Description of embodiments

[0065] Figure 1a , 1b Figure 1 shows connection areas of two embodiments of a boom segment 1, comprising an upper chord 2, a closing upper chord connection 21a, and an end face of a pressure plate 5 that connects and closes the lower chords 3. The illustrated elements of the upper chord connection 21a of a first boom segment 1 are connected to a complementary element of an upper chord connection 21b of a second boom segment 1b (not shown). At least one lower chord connection with a connecting device 4a of a first boom segment 1a is attached to the pressure plate 5 for transport purposes.

[0066] The elements of the at least one lower chord connection are located in the foot area of ​​the end face termination of the boom segment 1a and outside an end face termination 51 of the lower chords 3.

[0067] Figure 2a , 2b , 2cThe figures show the base area of ​​two cantilever segments 1a, 1b connected by means of the bottom chord connection, as well as the integration of these base areas into the truss or grid structure of the respective cantilever segment 1a, 1b from various spatial perspectives. The compression plates 5a, 5b lie directly against each other with their end faces 53 and are flush with each other at the end faces 51 (not visible in this illustration in the assembled state) of the bottom chords 3. The at least one bottom chord connection of this preferred embodiment is mounted on the compression plates 5a or 5b and is located in close proximity to the bottom chord 3 in the base area of ​​the cantilever segment 1a, 1b. Figure 2a and 2bThe heads of locking screws (standard screws) are indicated, which are located on the outer flange surface 75 of the flange 70 of the centering sleeve 7 in bores 78 (not shown) and by means of which the centering sleeve 7 is screwed into standard threads (not shown) located on the mounting side 52 of the pressure plate 5a, thus securing it against loss and / or rotation. Figure 2c The crown nut 10 and the washer 9 are shown as elements of the lower belt connection 4, which are located on the mounting side 52 of the pressure plate 5b.

[0068] Figure 2dFigure 1 shows the base area of ​​two cantilever segments 1a, 1b connected by means of the bottom chord connection, as well as the integration of these base areas into the truss or grid structure of the respective cantilever segment 1a, 1b in a three-dimensional perspective. The compression plates 5c lie directly against each other with their end faces 53 and are flush with each other at the end faces 51 (shown as dashed lines) of the bottom chords 3. The elements of the at least one bottom chord connection of this further embodiment are mounted on the compression plates 5c on the mounting side 52 and are located in close proximity to the bottom chord 3 in the base area of ​​the cantilever segment 1a, 1b.

[0069] Figure 3aFigure 1 shows a pressure plate 5a, extracted from the truss or grid structure of the respective cantilever segment 1b,1b, according to the preferred embodiment. The second through-openings 56 located in the pressure plate 5a each accommodate centering sleeves 7 (not shown) on their walls.

[0070] Figure 3b Figure 1 shows a pressure plate 5b, according to the preferred embodiment, which is detached from the truss or grid structure of the respective cantilever segment 1a, 1b. The first through-openings 54 in the pressure plate 5b are each enlarged in their upper region by a groove-like recess 55. The first through-openings 54 in the pressure plate 5b each accommodate the outer surfaces 63 (second outer surface section) of the connecting bolts 6 (not shown) on their walls. The pressure plate 5b provides a contact surface for the locking washer 9 (not shown) on the mounting side 52.

[0071] Figure 3c Figure 1 shows a pressure plate 5c, according to a further embodiment, which is detached from the truss or grid structure of the respective cantilever segment 1a, 1b. A first through-opening 54 in the pressure plate 5c is widened in its upper region by a groove-like recess 55. The first through-opening 54 in the pressure plate 5c receives the outer surface 63 (second outer surface section) of the connecting bolt 6 (not shown) on its wall. A second through-opening 56 in the pressure plate 5c receives the centering sleeve 7 (not shown) on its wall. The pressure plate 5c provides a contact surface for the locking washer 9 (not shown) on the mounting side 52.

[0072] In Figure 3a, 3b and 3cThe end face termination areas 51 represent the outer end areas of the printing plate 5a, 5b and 5c, which are located in the end face termination area of ​​the bottom chords 3 (not shown).

[0073] Figure 4The figure shows elements of the lower chord connection 4a, extracted from the truss or grid structure of the respective cantilever segment 1a, 1b in their unassembled state (exploded view), outside their engagement with the respective pressure plate 5a, 5b or 5c. The first fastening part of the connecting bolt 6, which can be inserted into the first through-opening 54 and the groove-like extension 55 on the end face 53 of the first pressure plate 5b or 5c, is subsequently screwed onto the mounting side 52 of the pressure plate 5b or 5c by means of the threaded section 64 (not shown), the washer 9 and the crown nut 10.The second fastening part of the connecting bolt 6, which can be inserted into the second through-hole 56 of the second pressure plate 5a or 5c, is secured during the subsequent assembly on the assembly side 52 of the second pressure plate 5a or 5c by means of the centering sleeve 7 inserted into the second through-hole 56 on the assembly side 52, as well as the plug wedge 8 (not shown) located in the locking groove 69 later in the assembly process and a spring pin (not shown) located in a locking bore 84 (not shown) of the plug wedge 8 (not shown).

[0074] Figure 5aFigure 1 shows the preferred embodiment, extracted from the truss or grid structure of the respective cantilever segment 1a, 1b, with connecting devices 4a of the bottom chord connection, as well as the different pressure plates 5a and 5b in the assembled state. It is evident that the connecting devices 4a are mounted parallel to each other on the respective pressure plates 5a and 5b, and elements of the bottom chord connections 4a protrude from the respective mounting side 52 of the pressure plate 5a. The end faces 53 (not shown) of the pressure plates 5a and 5b lie against each other over their entire surface, whereby the connection of the pressure plates 5a and 5b achieves a high degree of tightness by means of positive and frictional engagement between the end faces 53.

[0075] Figure 5bFigure 1 shows a further embodiment, extracted from the truss or grid structure of the respective cantilever segment 1a, 1b, with bottom chord connections and two identical pressure plates 5c in the assembled state. It is evident that the bottom chord connections are mounted alternately on the respective pressure plate 5c and that elements of the bottom chord connections protrude from the respective mounting side 52 of the pressure plates 5a and 5c. The end faces 53 (not shown) of the pressure plates 5c lie against each other over their entire surface, whereby the connection of the pressure plates 5c achieves a high degree of tightness by means of positive and frictional engagement between the end faces 53.

[0076] Figure 6Figure 1 shows a section through the connecting device 4a of the lower chord connection in its installed position, within the pressure plates 5 (in embodiments 5a, 5b, or 5c) connected by it. The end faces 53 of the pressure plates 5 (in embodiments 5a, 5b, or 5c) are in full contact with each other. The connecting bolt 6 is screwed to the first pressure plate 5b or 5c on the mounting side 52 by means of its threaded section 64, the attached washer 9, and the crown nut 10. To secure the position during the screwing of the connecting bolt 6 to the first pressure plate 5b or 5c, a centering pin 613 lies in the groove-shaped extension 55 of the first through-opening 54.

[0077] The centering sleeve 7 receives the cylindrical surface 62 (first cylindrical surface section) of the connecting bolt 6 radially on the inner wall 71 of its first sleeve section. In the axial direction of the centering sleeve 7, the wedge 8 rests against the outer flange surface 75 of the second sleeve section.

[0078] The centering sleeve 7 transmits the axial preload forces generated by the connecting bolt 6 and the wedge 8 located in the locking groove 69 by means of the flange 70 formed in its second sleeve section via its outer flange surface 75 and its inner flange surface 76 to the mounting side 52 of the second pressure plate 5 (in embodiments 5a or 5c).

[0079] In addition, the centering sleeve 7 transmits the radial preload forces introduced by the connecting bolt 6 via its cylindrical surface 62 (first cylindrical surface section) to the wall of the second through-opening 56 of the second pressure plate 5 (in embodiments 5a or 5c) by means of the inner wall 71 and the outer wall 72 of its first sleeve section.

[0080] Figure 7 Figure 6 shows the details of the connecting bolt 6. In particular, the cylindrical surface 63 (second cylindrical surface section) and the cylindrical surface 62 (first cylindrical surface section), as well as the first contact surface 65 and the second contact surface 66, represent the surfaces through which the axial and radial preload forces of the lower chord connection 4 generated by the connecting bolt 6 are introduced onto the end face 53 (not shown) of the pressure plate 5a, 5b or 5c (not shown) and the inner wall 71 (not shown) of the centering sleeve 7 (not shown).

[0081] Figure 8Figure 1 shows details of the centering sleeve 7. A tubular first sleeve section of the centering sleeve is bounded by an inner wall 71 and an outer wall 72, as well as by a surface 73 between the inner wall 71 and the outer wall 72, and terminates in a relief groove 79. A second sleeve section of the centering sleeve begins at the relief groove 79 and forms a circumferential flange 70 in the shape of a collar. The circumferential flange 70 has an outer flange surface 75 and an inner flange surface 76, as well as a lateral end 77. The bores 78 in the flange 70 accommodate standard screws (not shown) for securing the centering sleeve 7 to the mounting side 52 of the pressure plate 5a or 5c.These locking screws (not shown) are screwed to the pressure plate 5a or 5c on the mounting side 52 by means of standard threads located in the pressure plate 5a or 5c (not shown) and serve to secure the centering sleeve 7 against loss and / or rotation.

[0082] Figure 9Figure 1 shows the details of the wedge 8. The wedge 8, in its mounted or inserted position (not shown), lies within the locking groove 69 (not shown), which is located in the cylindrical surface 61 (third cylindrical surface section, not shown) of the conical centering mandrel of the connecting bolt 6 (not shown). The outer contour 82 of the wedge 8 forms, on the one hand, the contact surface with the inwardly facing wall 610 (not shown) of the locking groove 69 (not shown) and, on the other hand, with the outer flange surface 75 (not shown) of the centering sleeve 7 (not shown). The outer contour 83 forms the contact surface of the wedge 8 with the outwardly facing wall 611 (not shown) of the locking groove 69 (not shown) of the connecting bolt 6 (not shown). The outer contour 81 serves as a receiving surface for hammer blows, which are used for securing and, if necessary, tightening.The insertion of the wedge 8 within the locking groove 69 (not shown) must be entered.

[0083] The at least one locking bore 84 located in the lower part of the wedge 8 can accommodate a spring pin (standard part, not shown) for securing the wedge 8. In the inserted and set or repositioned position of the wedge 8, the at least one locking bore 84 lies in a space below the locking groove 69 (not shown) of the connecting bolt 6 (not shown).

[0084] Figure 10a and 10bFigure 1 shows the connection areas of two boom segments 1a, 1b according to a preferred embodiment, each comprising an upper chord 2, terminating upper chord connections 21a, 21b, and the end faces 53 of a pressure plate 5 connecting and terminating the lower chords 3. The illustrated elements of an upper chord connection 21a of a first boom segment 1a are connected to a complementary element of an upper chord connection 21b of a second boom segment 1b. Two fixing devices 4b and two connecting devices 4a of a first boom segment 1a are attached to the pressure plate 5. A screw mandrel 40 for each fixing connection 4b is located in the base region of the boom segment 1a in the end face termination 51 for each of the lower chords 3. The at least one through-opening 56 is located within the pressure plate 5 in the base region of the boom segment 1b and between the end faces 51.

[0085] At least one through-opening 57 for receiving the screw mandrel 40 is located in the pressure plate 5 in the foot area of ​​the boom segment 1b and within the end-face termination area 51.

[0086] Figure 11a Figure 1 shows the base of two boom segments 1a, 1b connected by means of the lower chord connections 4a and 4b according to a preferred embodiment in a sectional view (top view). The pressure plates 5a, 5b lie directly against each other with their end faces 53. The connecting devices 4a and the fixing devices 4b are mounted on the pressure plates 5a and 5b and are located in close proximity to the lower chords 3 in the base of the boom segment 1a, 1b.

[0087] Figure 11bFigure 1 shows a section of the base of two boom segments 1a, 1b connected by means of the connecting device 4a and the fixing device 4b according to a preferred embodiment in a sectional view (top view). The connecting device 4a and the fixing device 4b are mounted on the pressure plates 5a and 5b and are located in close proximity to the lower chord 3 in the base of the boom segment 1a, 1b.

[0088] The fixing device 4b comprises a bushing 45 which is arranged in the corresponding through-opening 57 within the pressure plate 5a, wherein the bushing 45 and the through-opening 57 preferably have no play relative to each other. This ensures that the bushing 45 is, on the one hand, firmly mounted within the through-opening 57 and, on the other hand, can preferably be pulled out and replaced by means of a bushing-pulling tool that engages the inner wall 46 of the bushing 45.

[0089] Figure 12Figure 1 shows a section of two cantilever segments 1a, 1b connected to each other by means of the fixing device 4b according to a preferred embodiment in a sectional view (side view). The screw mandrel 40 has a threaded section 41 in a first fastening section. The threaded section 41 is screwed into a threaded bore 58, the threaded bore 58 being located in the end face 51 of the pressure plate 5b. The screw mandrel 40 has a cylindrical surface section 42 in a second fastening section, which adjoins the threaded section 41. In the assembled state, the cylindrical surface section 42 of the screw mandrel 40 is located directly above the end face 53 of the pressure plate 5b and bears against the inner wall 46 of the bushing 45 in a form-fit and friction-fit manner.A chamfer 44 can be located between the head 43 of the screw mandrel 40 and the cylindrical surface section 42 of the screw mandrel 40, facilitating the insertion of the screw mandrel 40 into the bushing 45. The head 43 can, in particular, be hexagonal to accommodate a tool, which may be a wrench.

[0090] The outer wall 47 of the bushing 45 rests directly against the wall of the through-opening 57 within the pressure plate 5a. In the assembled state, the bushing 45 lies directly in front of the stiffening plate 31, which defines the rear end area within the bottom flange 3. The bushing 45 is not fixed to either the through-opening 57 or the stiffening plate 31 in the rear end area; instead, its outer wall 47 has a slight oversize compared to the diameter of the through-opening 57 and is detachably mounted within the rear end area by means of an interference fit.

[0091] Figure 13a Figure 1 shows a pressure plate 5a, extracted from the truss or grid structure of the respective cantilever segment 1b,1b, according to a preferred embodiment. The through-openings 56 in the pressure plate 5a each accommodate centering sleeves 7 (not shown) on their walls. The through-openings 57 in the pressure plate 5a each accommodate bushings 45 (not shown) on their walls.

[0092] Figure 13bFigure 1 shows a pressure plate 5b, extracted from the truss or grid structure of the respective cantilever segment 1a, 1b, according to a preferred embodiment. The through-openings 54 in the pressure plate 5b are each enlarged in their upper region by a groove-like recess 55. The through-openings 54 in the pressure plate 5b each accommodate the cylindrical surfaces 63 (second cylindrical surface section) of the connecting bolts 6 (not shown) on their walls. Metric internal threads (not shown) are provided in the threaded bores 58 in the pressure plate 5b, which each engage the metric external threads of the screw mandrels 40 (not shown) located in the threaded sections 41. Reference symbol list

[0093] 1a, 1b Boom segment 2 Top chord 21a, 21b Top chord connection 3 Bottom chord 31 Stiffening plate 4a Connecting device 4b Fixing device 40 Screw mandrel 41 Threaded section of the screw mandrel 42 Shell surface section of the screw mandrel 43 Head area 44 Chamfer 45 Bushing 46 Inner wall of the bushing 45 47 Outer wall of the bushing 45 5 Pressure plate (pressure plate 5a, 5b, 5c) 51 End face termination area above the bottom chord ends 52 Mounting side of the pressure plate 5a, 5b, 5c 53 End face of the pressure plate 5a, 5b, 5c 54 First through-hole within the pressure plate 5b, 5c 55 Groove-shaped widening of the first through-hole 54 56 Second through-hole within the pressure plate 5a, 5c 57 Through-hole within the pressure plate 5a, 5c 58 Threaded bore within the pressure plate 5b 6 Connecting bolt 61 Circular surface (cone) of the centering mandrel of the connecting bolt (third lateral surface section) 62 Circular surface (cylinder) of the connecting bolt (second lateral surface section) 63 Circular surface (cylinder) of theConnecting bolt (first outer surface section) 64 Screw thread section 65 First contact surface of the connecting bolt 66 Second contact surface of the connecting bolt 67 Chamfer (between outer surface section 1 and outer surface section 2) 68 Chamfer (between outer surface section 1 and outer surface section 2) 69 Locking groove in the centering mandrel of the connecting bolt (fourth section) 610 Inner wall of the locking groove (contact surface of the outer contour 1 of the wedge 8) 611 Outer wall of the locking groove (contact surface of the outer contour 2 of the wedge 8) 612 Bore in the outer surface 63 of the connecting bolt 613 Centering pin for centering the connecting bolt in the groove-shaped extension 55 7 Centering sleeve 70 Flange (second sleeve section of the centering sleeve, collar) 71 Inner wall of the first Sleeve section of the centering sleeve 72 Outer wall of the first sleeve section of the centering sleeve 73 Surface between the inner and outer wall of the first sleeve section of the centering sleeve 74 Chamfer between theSurface and inner wall of the first sleeve section of the centering sleeve 75 Outer flange surface of flange 70, outer contact surface of the second sleeve section of the centering sleeve (bearing surface for the second contact surface of the wedge) 76 Inner flange surface of flange 70, inner contact surface of the second sleeve section of the centering sleeve (contact surface for the mounting side of the pressure plate) 77 Lateral end of the centering sleeve 78 Bores for receiving locking screws 79 Undercut between first and second sleeve sections of the centering sleeve 8 Wedge 81 Outer contour of a first contact surface of the wedge 82 Outer contour of a second contact surface of the wedge 83 Outer contour of a third contact surface of the wedge 84 Locking hole for receiving a spring pin (standard part) 9 Washer (standard part) 10 Crown nut (standard part)

Claims

1. Bottom chord connection with a connection device (4a), in particular for connecting cantilever segments (1) of a cantilever of a tower crane, comprising: - at least one connection bolt (6) with a first fastening part (9, 10, 63, 64) for fastening to a first pressure plate (5, 5a, 5b, 5c) of a first cantilever segment (1a) and with a second fastening part (61, 62) for fastening to a second pressure plate (5, 5a, 5b, 5c) of a second cantilever segment (1b), wherein the first fastening member (9, 10, 63, 64) is provided with a releasable, twist-proof connecting means for fastening to the first pressure plate (5, 5a, 5b, 5c), wherein the second fastening part (61, 62) is provided with a centering mandrel for fastening to the second pressure plate (5, 5a, 5b, 5c), which has a radial, in particular continuous, securing slot (69) for receiving a plug-in part (8); characterized in that that the bottom chord connection comprises a centering sleeve (7) for inserting into a corresponding through-opening (54, 56) in the second pressure plate (5, 5a, 5b, 5c), which has an internal cross-section for positively receiving the second fastening part (61, 62).

2. Bottom flange connection with a connection device (4a) according to claim 1, wherein the centering pin has a section tapering towards the second fastening part (61, 62) and adjoins a first cylindrical lateral surface section which, in an assembled state, can be received in the centering sleeve, in particular in a form-fitting manner.

3. Lower chord connection comprising a connection device (4a) according to claim 1 or 2, wherein the centering sleeve (7) has a wholly or partially circumferential flange (70) with flange areas (75, 76) which is provided at an axial end of the centering sleeve (7) and is arranged in an assembled state in the direction of the second fastening part (61, 62).

4. Lower chord connection comprising a connection device (4a) according to claim 3, wherein the flange (70) is provided with flange areas (75, 76) and bores (78) by means of one or more fastening means for non-rotational fastening and securing to the second pressure plate (5, 5a, 5b, 5c).

5. Lower chord connection with a connection device (4a) according to any one of claims 1 to 4, wherein the first fastening member (63, 64) has a second cylindrical lateral surface portion which in particular directly adjoins the second fastening member (61, 62).

6. Lower chord connection comprising a connection device (4a) according to claim 5, wherein a screw threaded portion (64) adjoins the second cylindrical skirt surface portion (63) to fasten the first fastening member (63, 64) to the first pressure plate (5, 5a, 5b, 5c) by screwing.

7. Lower chord connection comprising a connection device (4a) according to any one of claims 5 to 6, wherein the second cylindrical shell surface portion (63) is provided with an anti-rotation means, in particular formed with a centering pin (613) projecting from the second cylindrical shell surface portion.

8. Lower chord connection with a connection device (4a) according to one of claims 1 to 7, wherein the second pressure plate (5, 5a, 5b, 5c) is provided with a continuous second through opening (56) for receiving the centering sleeve (7) in a form-locking and friction-locking manner in the axial and radial direction.

9. Lower belt connection with a connection device (4a) according to any one of claims 1 to 8, wherein the first pressure plate (5, 5a, 5b, 5c) is provided with a first through-opening (54) for receiving the second lateral surface portion (63) in a form-locking and friction-locking manner in the radial and axial directions, wherein in an assembled state an axial end of a first lateral surface portion (62) of the second fastening part (61, 62) bears against the first pressure plate (5, 5a, 5b, 5c).

10. Lower chord connection comprising a connection device (4a) according to claim 9, wherein the first lateral surface portion (62) has an axial length at least equal to the thickness of the second pressure plate (5, 5a, 5b, 5c), wherein the securing slot (69) is arranged such that, in an assembled state in which the first and second pressure plates (5, 5a, 5b, 5c) abut against each other, a force is exerted against the second pressure plate (5, 5a, 5b, 5c) in the direction of the second fastening part (61, 62) when the plug-in part (8) is inserted.

11. Lower chord connection comprising a connection device (4a) according to any one of claims 1 to 10, wherein at least one further connection bolt (6) is provided with a first fastening part for fastening to the second pressure plate (5, 5a, 5b, 5c) of the second cantilever segment (1b) and with a second fastening part for fastening to the first pressure plate of the first cantilever segment (1a), wherein the first fastening member (63, 64) is provided with a releasable connecting means for fastening to the second pressure plate (5, 5a, 5b, 5c), wherein the second fastening part (61, 62) is provided with a centering pin for fastening to the first pressure plate (5, 5a, 5b, 5c), which has a radial, in particular continuous, securing slot for receiving a plug-in part (8); - a centering sleeve (7) for inserting into a corresponding through-opening in the first pressure plate (5, 5a, 5b, 5c), which has an internal cross-section for receiving the second fastening part (61, 62) in a form-fitting manner.

12. Lower chord connection comprising a connection device (4a) according to any one of claims 1 to 11, wherein the lower chord connection connects two lower chords (3) of the cantilever segments (1a,1b) with each other, wherein a fixing device (4b) is provided at the end face of each of the two lower chords (3) in order to secure the lower chords (3) against displacement transversely to their axial direction.

13. Lower chord connection comprising a connection device (4a) according to claim 12, wherein the fixing device (4b) comprises: - at least one screw mandrel (40) having a first fastening portion for fastening to the first pressure plate (5,5b,5c) and having a second fastening portion for fastening to the second pressure plate (5,5a,5c), wherein the second mounting portion having a peripheral surface portion (42) for mounting said mandrel (40) to said second pressure plate (5,5a,5c), wherein a bushing (45) is provided for inserting into a through opening (57) in the second pressure plate (5,5a,5c), wherein the bushing (45) has an inner wall (46) to receive the mantle surface portion (42) of the second attachment portion.

14. Lower chord connection with a connection device (4a) according to claim 13, wherein the first fastening portion is provided with a threaded portion (41) for fastening the screw mandrel (40) to a threaded hole (58) in the first pressure plate (5,5b,5c).

15. Lower chord connection comprising a connection device (4a) according to claim 13 or 14, wherein the lateral surface portion (42) of the second fastening portion is received in the through-opening (57) in a form-fitting and friction-fitting manner.