Bottom chord connection device with a connecting device

Abstract

The present invention relates to a connecting device, in particular for connecting cantilever segments (1) of a cantilever of a tower crane, comprising at least one connecting bolt (6) having 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 a second fastening part (61, 62) for fastening to a second pressure plate (5, 5a, 5b, 5c) of a second cantilever segment (1b), where the first fastening part (9, 10, 63, 64) is connected to the first pressure plate (5, 5a, 5b, 5c) of the first cantilever segment (1a) and a second fastening part (61, 62) for fastening to a second pressure plate (5, 5a, 5b, 5c) of a second cantilever segment (1b), c), the second fastening parts (61, 62) comprise a centering mandrel for fastening to the second pressure plate (5, 5a, 5b, 5c), the centering mandrel having radial fastening grooves, in particular continuous fastening grooves, for receiving the plug parts (8), and a centering sleeve (7) for insertion into corresponding through holes (54, 56) of the second pressure plate (5, 5a, 5b, 5c), the centering sleeve having an internal cross-section for securely receiving the second fastening parts (61, 62).

Description

[Technical field]

[0001] The present invention relates to a cantilever for a tower crane, in particular a cantilever in the form of a crane part known in the art as a trolley cantilever or trolley carriage. Furthermore, the present invention relates to a bottom chord connection for the connection of cantilever segments for such a cantilever. [Background technology]

[0002] A cantilever of a tower crane is usually composed of individual cantilever segments that are removably connected by means of a connecting device. Such a cantilever has, in addition to other structural features, at least one lower chord and at least one upper chord. The lower chord is preferably made of steel tubes with a square profile, and the upper chord is preferably made of flat steel, steel tubes with a square profile or steel tubes with a circular profile. The at least one upper chord serves mainly to absorb forces caused by tensile loads and is located in the head region of the cantilever segment. The at least one lower chord serves mainly to absorb forces caused by compressive loads and is located in the foot region of the cantilever segment. The cantilever segments feature connecting devices in the region where they are connected to each other. These connecting devices close the end faces of at least one upper chord or at least one lower chord for each cantilever segment.

[0003] The particular layout of the cantilevers of tower cranes is called trolley cantilever or trolley carriage, because they provide the tracks (raceways) and lateral guides for the deflection devices for the hoisting ropes, deflection devices known among specialists as trolleys or clubs.

[0004] Insofar as such steel structures or crane cantilevers have steel structure or cantilever segments based on a truss or lattice structure, which are connected by connecting devices, such cantilevers can also be used within steel structures, e.g. for the construction of mobile steel halls or festival halls, or for cantilevers of other types of cranes, such as mobile port cranes or semi-fixed storage yard cranes.

[0005] The individual cantilever segments of a tower crane cantilever are usually connected to one another, i.e. assembled, preferably on the ground before the commissioning of the crane. In exceptional cases, a cantilever segment is added to an already operational tower crane cantilever using detachable connection techniques to extend the cantilever. The detachable connection must therefore be suitable for both mounting scenarios and must be structurally designed accordingly.

[0006] The connection techniques used in the construction of such cantilevers composed of cantilever segments involve only a few connecting parts, which are typically easy to handle, maintenance-free, backlash-free and low wear. Summary of the Invention [Problem to be solved by the invention]

[0007] A cantilever for a tower crane is known, for example, from EP 1 728 756 A1. This cantilever is characterized by a connection device formed by a trunnion and a centering pin between two cantilever segments, with separate recesses for receiving these pins and a fixing part which is operatively connected to one another and which fixes the cantilever segments to one another on the one hand and removably connects them to one another on the other hand. Among experts, this connection device is also known as Liebherr LiConnect (see p. 18 of the "LIEBHERR ECB LiConnect" website brochure). A first disadvantage of such a cantilever segment lower chord connection device is that the connection device, due to its arrangement, can only absorb forces via a limited area of ​​the end face of the lower chord. The cross members of the ECB cantilever, which are located between the foot-side lower chords, are not directly connected to one another in the connection area in terms of the steel structure and therefore do not transmit forces in the front connection area of ​​the segments, in other words are not directly connected to one another mechanically. The wear pattern of the connection device designed according to the LiConnect concept is therefore pronounced, as the transmitted forces are only transferred to a limited area via the area of ​​the end face located on the outside of the trunnion. The resulting load-bearing pattern is distinguished by very high local forces and the associated occurrence of stress peaks.

[0008] Moreover, the lateral forces and the resulting moments generated by the rotation of the tower crane in the foot region of the cantilever are not fully absorbed by the connecting device designed in this way. In other words, no local counter moment is generated, especially by the trunnion, which can lead to permanently large deformations of the cantilever segment in its foot region, especially in the foot region of the connecting device. The cantilever structure therefore requires a strong steel structure in the lower chord and their integration in the truss of the cantilever segment. In this context, other disadvantages are the relatively complex structure of the connecting device, especially in the end region of the lower chord (the so-called joint), the so-called sealing caulking, i.e. the closure of the trunnion and the trunnion itself, in order to ensure a permanent and reliable fit of the connecting parts. The opening of the joint during the operation of the crane cannot be permanently avoided, despite this approach with respect to the steel structure. Furthermore, the trunnion will wear out at its receiving portion due to friction and dynamic bearing play, which cannot be adjusted or compensated for after the fact and which is why the tolerances of the mount and trunnion must be tightly specified from the outset.

[0009] A cantilever for a tower crane is known from EP 1 468 955 A1, the end faces of which of the lower chords are designed as cross members and extend transversely to the longitudinal axis of the cantilever. The cross members have circular cutouts (holes), a first of which receives a clamping bolt which is fixed by an insert part. This insert part is not fixed in position and is secured against removal by a fixing catch (cotter pin). A second circular cutout (hole) of the cross member receives a centering bolt in the end face area of ​​the lower chord. At the end of the lower chord, a centering bolt is arranged in the cross member of the lower chord to be connected, which engages complementarily with a circular cutout in the end part of the cross member of the other lower chord to be connected. These centering bolts are designed as cylinders with a stepped cross section and two successive conical areas with different side pitches, the cylindrical part in the end part having the function of a seal.

[0010] The removable connection devices between the lower chords are represented by locking units consisting of several links, which are arranged spatially close to but distant from the respective end centering bolts. Each link unit is equipped with a clamping bolt, which is variably mounted in the longitudinal direction of the cantilever segment parallel to the lower chords along a carriage welded to the cross member. Each connection movement between the lower chords is realized by the clamping bolt sliding forward along a slide into a circular notch of the end cross member of the other cantilever segment and the locking insert being inserted into the head of the clamping bolt. A first drawback of the connection devices of the cantilever segments designed in this way is that the connection units are not able to fully absorb the forces and moments that occur. Another drawback is that the end cross members arranged between the lower chords at the foot end are not directly connected to each other over a wide area of ​​the connection area of ​​the steel structure, so that these end cross members can only absorb forces locally and to a limited extent in the end connection area of ​​the segments. Being located away from the end face of the lower chord, the connection device mainly absorbs axial bending moments and only small lateral forces, and is unable to generate corresponding bearing forces or reaction moments. The forces acting on the lower chord connection are taken between the forward fixing point and the generating point of the connection, which results in larger steel structural measures to absorb these transmitted forces without deforming the foot side cantilever areas and the connection parts. Another disadvantage is the relatively complex structure of this connection device, which has many parts that are secured against losses.

[0011] One of the objectives of the present invention is to design a removable connection of cantilever segments that is simple in design and consists of few parts, while being suitable for absorbing the large forces and moments acting on the cantilever parts during the operation of the crane, which should ideally be counteracted by creating local, adjustable support forces and reaction moments. [Means for solving the problem]

[0012] This problem is solved by a connection device for cantilever segments according to claim 1 and the dependent claims.

[0013] Further embodiments are provided by the dependent claims.

[0014] In a first aspect, the lower chord connection device comprises a connection device for connecting cantilever segments of a cantilever of a tower crane, at least one connecting bolt having a first fastening portion for fastening to a first pressure plate of the first cantilever segment and a second fastening portion for fastening to a second pressure plate of the second cantilever segment; the first fastener portion includes a releasable anti-torsion connection means for attachment to the first pressure plate; the second fastening part comprises a centering mandrel for mounting on the second pressure plate, which has a radial, in particular continuous, fastening groove for receiving the plug; and at least one centering sleeve for insertion into a corresponding through hole in the second pressure plate, the centering sleeve having an internal cross-section for securely receiving the second fastener.

[0015] In particular, the first through-hole arranged in the first pressure plate, of which there is at least one, can be designed to receive the connecting bolt in a form-fitting manner, in particular in the axial and radial direction of the through-hole, and in particular, the through-hole provided in the second pressure plate can be designed to receive the centering sleeve in a form-fitting manner and with frictional locking, in the axial and radial direction of the through-hole in the second pressure plate.

[0016] The connecting device according to the invention is therefore particularly characterized in that its parts advantageously combine the function of a fixed screw connection with the function of a removable screw-on connection by means of an adjustable centering part and a fixing part.

[0017] The proposed connection device mainly uses standard parts with a small number of dedicated parts in the operational connection, achieving a high degree of standardization and calculability in the design of the individual parts and therefore, ultimately, a high functional reliability of the cantilever.

[0018] To increase the stiffness of the lower chord region, it has also proven to be advantageous if the ends of the lower chords of the cantilevered segments are suitably connected to one another via at least two pressure plates. By forming a flat contact between at least two pressure plates and closing the front side of the cantilevered segments in their foot region, these instead provide the function of two mechanically connected cross members. Since the lower chords are connected together in the steel structure by these cross members and can have the same external shape, the force and moment absorbing cross section can be duplicated in the foot region of the cantilevered segments. The structure of the cantilevered segments is therefore reinforced in the region where the maximum bending and shear forces and moments act on the lower chords.

[0019] The pressure plate integrated in the front foot region of the cantilever segment allows the formation of the maximum effective transmission area, through which the connection between the lower chord regions of the two cantilever segments is established, which is not only located directly on a limited area of ​​the surface at the front end region of the lower chord, but also through a maximum front foot area extending in a plane formed transversely or obliquely to the longitudinal axis of the cantilever.

[0020] It is furthermore advantageous if the connecting device comprises at least one connecting bolt, which is preferably formed integrally and rotationally symmetrically, a first through hole in the first pressure plate for receiving the connecting bolt, a centering sleeve arranged between the connecting bolt and the second through hole in the second pressure plate, and a plug-in part.

[0021] The parts of the connection device attached to the cantilever segments to be connected complement each other. For this purpose, the first cantilever segment has a first pressure plate in the foot area of ​​its front end. This first pressure plate receives the connection device, by means of which the second pressure plate present on the second cantilever segment to be connected is connected. The first and second pressure plates connected by the connection device are mainly in contact with each other, so that when determining the connection force generated between the cantilever segments by the connection device, frictional contact between the first and second pressure plates can be neglected.

[0022] The first fastening part can in particular have a second cylindrical side part adjoining the second fastening part. In particular, the first fastening part can have a thread part adjoining the second cylindrical side part, and the first fastening part can be fastened to the first pressure plate by means of a screw. The second cylindrical side part can be provided with an anti-rotation device, which is in particular formed by a centering pin protruding from the second cylindrical side part.

[0023] In 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 in order to accommodate several connecting bolts in the same direction. In this case, the same (preferably parallel to their longitudinal direction) direction of the attached connecting bolts should be understood so that, by receiving simultaneously, the connecting bolts arranged in and on the pressure plate are oriented in the same direction.

[0024] At least one other connecting bolt comprises a first fastening part for fastening to the second pressure plate of the second cantilever segment and a second fastening part for fastening to the first pressure plate of the first cantilever segment, the first fastening part comprising a removable connection device for fastening to the second pressure plate and the second fastening part comprising a centering mandrel for fastening to the first pressure plate, the centering mandrel having a radial, in particular continuous, fixing groove for receiving the plug-in part and a centering sleeve for insertion into a corresponding through hole of the first pressure plate, the centering sleeve having an internal cross-section for receiving the second fastening part in a form-fitting manner.

[0025] According to another possible embodiment of the connecting device, it has proven advantageous for the first and the second pressure plate to each have at least one first through hole and at least one second through hole for alternatingly accommodating a number of connecting bolts. The term "alternate mounting" refers to the orientation of the connecting bolts such that at least two connecting bolts arranged in and on the pressure plate face in opposite directions.

[0026] At least one first through-hole can be widened in its upper area with respect to the groove in order to accommodate a centering pin, which is advantageous for fixing the connecting bolt against rotation during screwing into the pressure plate. This allows the insertion of the plug-in part into the fixing groove located in the head of the connecting bolt to always take place vertically from above, which is advantageous when assembling the cantilever segments on the ground side at the construction site, in particular when assembling the cantilever segments during the operation of the crane, sometimes at airy height. The connecting bolt is attached to one end of the first part (threaded part), which is distinguished by a first cross section, in particular with a metric thread of a common pitch.

[0027] The second part of the connecting bolt has a first shoulder adjacent to the first part (threaded part), from which the first cross section of the connecting bolt widens to the second cross section of the connecting bolt. The first cross section and the second cross section form a first fastening part of the connecting bolt. Between the first cross section of the connecting bolt and the second cross section of the connecting bolt a first contact surface is formed, which is non-circular and has a first chamfer in its upper region. This chamfer allows the connecting bolt to be more easily screwed into the at least one first through hole of the first pressure plate, which is particularly beneficial for the installation of the connecting bolt.

[0028] The second part of the connecting bolt (the second cylindrical side part) is distinguished by a first side face, in which a hole is provided for receiving a centering pin. When the connecting bolt is screwed in, this centering pin is received in a groove, which serves to radially fix the connecting bolt in the extension of the at least one first through hole of the first pressure plate.

[0029] During assembly, the first and second parts of the connecting bolt are inserted into at least one first through hole of the first pressure plate. The lock washer is disposed on a part of the first part (threaded part) protruding from the mounting side of the first pressure plate, so that the threaded crown nut can come into flat contact with the threaded part of the mounting side of the first pressure plate. This advantageously ensures that the screw force is applied evenly and predictably to the mounting side of the first pressure plate over a large cross section.

[0030] The side of the second part of the connecting bolt ends in a second shoulder, the entire surface of which is in contact within at least the first through hole of the first pressure plate, thereby ensuring, on the one hand, radial fixation of the connecting bolt in the first pressure plate and, on the other hand, a low-rebound connection between the connecting bolt and the first pressure plate.

[0031] The third cross section of the connecting bolt (first cylindrical side cross section) extends from the second shoulder, from where the second cross section of the connecting bolt widens to the third cross section of the connecting bolt. Between the second cross section of the connecting bolt and the third cross section of the connecting bolt, a second contact surface is formed, which is in direct contact with the end face of the first pressure plate. This second contact surface provides both the axial contact of the connecting bolt and the transfer of the axial pretension force set by the connecting bolt to the end face of the first pressure plate.

[0032] The third part of the connecting bolt (the first cylindrical side part) is distinguished by a second side part. This side part merges into a fourth part of the connecting bolt called the head. The third part and the fourth part form the second fastening part of the connecting bolt.

[0033] Furthermore, the connecting bolt can have, in its head region, a portion which tapers towards the second fastening portion and adjoins the first cylindrical side portion, which in the mounted state is received in the centering sleeve in a particularly form-fitting manner.

[0034] The taper in the head region of the connection bolt can be distinguished by a third flank, which is designed as a cone and thus forms a centering mandrel, which opens onto the second chamfer and forms the other end of the connection bolt.

[0035] The second chamfer and the conical surface of the centering mandrel of the connecting bolt cooperate to facilitate the insertion of the connecting bolt and the centering sleeve into the at least one second through-hole of the second pressure plate, which greatly facilitates the installation of the cantilever segments to be connected, which is particularly beneficial for safe handling and installation of the cantilever segments.

[0036] Other advantages of the new connection device for the lower chord connection are given in particular by the introduction of a centering sleeve. For this purpose, the centering sleeve is made with a full or partial circumferential flange, which can be provided at the axial end of the centering sleeve and is also arranged in the assembled state in the direction of the second fastening. This centering sleeve can thus be designed as a collar bushing and is distinguished by a tubular first sleeve part, which does not necessarily have to be circular, and has an inner and outer wall with an intermediate surface, which does not necessarily have to be designed as an annular surface. At the first end of the first sleeve part, a chamfer can be arranged between the surface and the inner wall, which facilitates the insertion of the centering sleeve into the second side of the connecting bolt as an aid to the complementary insertion of the connecting bolt into the conical part of the centering mandrel.

[0037] At the second end of the first sleeve part of the centering sleeve there is an undercut to which the second sleeve part of the centering sleeve is connected. This second sleeve part is distinguished by a peripheral flange with inner and outer flange surfaces. The flange surfaces of the flange thus have a first bearing surface and a second bearing surface and an inner diameter and an outer diameter, and therefore this second sleeve part has a collar shape. This collar is cut on one side of the outer cross section, which allows more freedom in the design of the structural steel of the cantilever segment.

[0038] The centering sleeve is arranged, as described above, between the side of the first cylindrical side part of the connecting bolt and the wall of at least one second through hole provided in the second pressure plate. For this purpose, the centering sleeve is dimensioned axially and radially in such a way that it achieves full support over the maximum contact area with the second side part of the connecting bolt on the one hand and with the wall of at least one second through hole of the second pressure plate on the other hand. Due to the undercut between the first and second sleeve parts of the centering sleeve, a flat and shoulder-free contact of the centering sleeve can be formed by the inwardly directed undercut radius between the first and second sleeve parts of the centering sleeve.

[0039] Both the centering sleeve and at least the second through hole of the second pressure plate can be structurally designed in their cross section or diameter so that in interaction they fulfill the design of a clearance fit. In this way, these two parts ensure, on the one hand, an optimal transmission of radial forces acting on the centering mandrel and, on the other hand, the absorption of moments acting on the length of the centering mandrel fixed to the second pressure plate. When manufacturing the centering sleeve as a rotating part, close tolerances should be applied to the dimensions of the outer wall of the first sleeve section of the centering sleeve so that it has a minimum clearance at least in its mounting position relative to the wall of the second through hole.

[0040] Another advantage of the connecting device is that the axial force is applied in particular via the engaged inner and outer contact surfaces of the centering sleeve of the second sleeve section, whereby the axial pretension caused by the centering mandrel and the plug allows for a uniform maximum surface pressure between the first and second pressure plates. The elastic centering sleeve and the elastic pressure plate, in cooperation with the bending-resistant centering bolt, improve the bending, lateral force and moment absorption of the connecting device and optimize the recovery behavior of the connecting device.

[0041] Another advantage of the centering sleeve is in particular the design of its complete or partial circumferential flange, which, as mentioned above, can be designed as a collar. The collar arranged on the second sleeve section is distinguished in particular by an inner flange surface and an outer flange surface. The bearing surface formed between the inner and outer diameter of the collar can be designed according to the area and therefore the resistance associated with the surfaces of the first and second pressure plates. Due to their radial 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 pretension forces on the second and / or first pressure plate, which are generated by the tension of the plug-in part in the fixing groove of the centering mandrel. By adapting the outer cross-section of the centering sleeve in the second sleeve section, i.e. the collar or its flange, it is possible, on the one hand, to advantageously generate a maximized inner flange surface for full-surface contact of the mounting side of the second pressure plate and / or the first pressure plate with the centering sleeve, and, on the other hand, to advantageously create the largest possible outer flange surface for full-surface contact of the second contact surface of the plug-in part.

[0042] Additionally, one or more fastening devices may be provided to non-rotatably fasten the flange of the centering sleeve to the first pressure plate and / or the second pressure plate.

[0043] To fasten the connecting device, a plug-in part is used, which is preferably inserted from above into a fastening groove provided in the conical centering mandrel of the connecting bolt. The plug-in part can be designed with different lengths so that its contact surface fits the outer flange surface of the second sleeve section of the centering sleeve.

[0044] Another advantage of the connecting device is that it is adjustable: the adjustability is realized in particular by means of the plug-in part, the position of which can be changed within limits.

[0045] After the connecting bolt has been pressed into the at least one second through hole of the second pressure plate, and after the centering sleeve has been inserted into the free space formed between the second side of the connecting bolt and the wall of the at least one second through hole, the plug portion is inserted into a continuous fixing groove located in the conical region of the centering mandrel of the connecting bolt.

[0046] The plug part is solid and can have a different contour at each contact surface. The contour of the first contact surface forms the head-side termination and absorbs the clamping force preferably introduced by a hammer blow during assembly of the connection device. The contour of the second contact surface contacts the outer flange surface of the centering sleeve in the assembled state of the connection device and introduces axial and radial clamping forces thereto by means of a secure fit. The contour of the third contact surface can have a rounded shape. The rounded contour ensures that the entire surface of the third contact surface of the plug part contacts the outer wall of the fixing groove of the centering mandrel, which allows maximum tightening of the plug part in the centering mandrel.

[0047] This third contact surface can be angled relative to the second contact surface and presses the insert piece in the fastening groove of the connecting bolt against the inner and outer walls of the fastening groove, respectively.

[0048] During installation, the plug-in part can be fixed against upward movement by means of a fastening plug, which can be designed in the form of a spring cotter (standard part). Depending on the insertion depth of the plug-in part in the fastening groove, the plug-in part can be fixed in the respective position in the fastening groove by inserting the fastening plug into at least one fastening hole in the lower leg area of ​​the plug-in part. This makes it possible to permanently guarantee a permanent fixation of the plug-in part in the fastening groove of the connecting bolt on the one hand and against the outer contact surface of the centering sleeve and thus against the mounting side of the first and / or second pressure plate on the other hand and a sufficient tensioning of the plug-in part.

[0049] Depending on the wear of the lower chord connection, which depends on the duration of use of the crane and the associated deformations of the individual cantilever segments, the strength of the lower chord connection can be maintained at a permanently high level by slippage of the plug under its own weight or by mechanical readjustment of the plug, in particular by hammer blows.

[0050] In the case of the lower chord connection, the connection device can be modeled with a fixed bearing. In another aspect, in a preferred embodiment, it has been shown to be advantageous to use another cantilever connection to relieve the load of the connection device according to the invention, in that embodiment as a fixed bearing. The other cantilever connection can be formed by an additionally introduced fixing device, which can be designed as a floating bearing complementary to the fixed bearing of the connection device. In this case, the fixed bearing can be arranged on the outside of the end face of the lower chord. The floating bearing can be arranged on the end face of the lower chord or on the inside of the lower chord. The contact surface formed directly at the joint located above the end of the tube of the lower chord is located transversely to the longitudinal axis of the cantilever and should be understood as the front end of the lower chord. Due to the interaction of the fixed bearing and the loose bearing, the lower chords of the two cantilever segments to be connected, in particular the joint located above the end of the tube of the lower chord, are on the one hand fixed in position relative to each other and on the other hand permanently and removably connected to each other by an adjustable connection force.

[0051] A mobile dolly can be arranged along the lower cantilever. If the dolly travels in the area of ​​the cantilever connection, i.e. the cantilever joint, the load from the dolly can exert maximum bending moments on the pressure plate in the end face area of ​​the lower chord during the crane operation. This can result in permanent local deformation of the front area of ​​the cantilever joint, such that at least one step is formed between the opposing and adjacent cantilever joints. Since the lower chord usually has the surface on which the dolly travels, such a step can result in mechanical shocks during the travel of the dolly under load.

[0052] In another aspect, the above-mentioned bottom chord connection comprises a connection device, which connects two individual bottom chords of a cantilever segment, i.e., a bottom chord of a first cantilever segment and a corresponding bottom chord of a second cantilever segment, to each other, and a fixing device is provided on the end faces of the two individual bottom chords to fix the bottom chords against lateral displacement relative to their axial direction.

[0053] It has therefore proved to be advantageous that an additional fastening device introduced in the highly loaded bottom chord area of ​​the pressure plate can support the centering effect of the connection device. This local support caused by the fastening device leads to an additional relief of the connection device and to a permanent and wear-free fixation of the bottom chords to each other in the joint area located in the adjacent area above the front end of the tube of the bottom chord. In particular, the fastening device can be arranged on the front termination surface, i.e. in the center of the bottom chord joint. Other arrangements of the fastening device in the bottom chord connection are conceivable, for example in the area above or below the structural center of each bottom chord or in a lateral area.

[0054] Furthermore, the fixing device at least one screw mandrel having a first fastening portion for fastening to a first pressure plate and a second fastening portion for fastening to a second pressure plate; the second fastening portion has a side portion for fastening the screw mandrel to the second pressure plate; A bushing is provided for insertion into the through hole in the second pressure plate; The bushing has an inner wall that receives the mantle surface portion of the second fastener within the throughbore.

[0055] Additionally, the first fastener may include a threaded portion for fastening the screw mandrel to the threaded hole in the first pressure plate.

[0056] The side portion of the second fastening portion may be adapted to be received in the through hole in a form-fitting and frictionally secured manner.

[0057] Thus, in addition to the connection device according to the invention, at least one other fastening device can be provided, which is at least one screw mandrel having a first fastening portion for fastening to a first pressure plate of a first cantilever segment and a second fastening portion for fastening to a second pressure plate of a second cantilever segment; the first fastening portion includes a threaded portion for fastening the screw mandrel to the threaded hole of the first pressure plate; the second fastening portion has a side portion for fastening the screw mandrel to the second pressure plate; at least one socket for insertion into a corresponding through hole, The through hole is provided in the second pressure plate, The bushing has an inner wall for receiving a lateral portion of the second fastening portion in a form-fitting and frictionally secured manner.

[0058] Other advantages of the novel lower chord connection are therefore given, in particular, by the introduction of an additional fastening device. The parts of the fastening device attached to the cantilever segments to be connected complement each other. For this purpose, the first cantilever segment has a first pressure plate in the foot area of ​​its front end. This first pressure plate accommodates the above-mentioned connecting device and a fixed connection, by means of which the second pressure plate of the second cantilever segment to be connected is connected. The first and second pressure plates connected by the connecting and fastening device are in reliable contact with each other mainly over their entire surface, so that when determining the connection forces generated between the cantilever segments by the connecting and fastening devices, frictional contact between the first and second pressure plates can be neglected.

[0059] Furthermore, it is advantageous for at least one fastening device to comprise a rotationally symmetrically designed screw mandrel, preferably in one piece, with a first fastening part and a second fastening part, a threaded hole in the first pressure plate for receiving the first fastening part, another through hole in the second pressure plate for receiving the second fastening part, and a bushing arranged between the second fastening part and the other through hole. The first fastening part of the fastening device can have a threaded part that abuts on a preferably cylindrical side part of the second fastening part of the fastening device. In particular, the first fastening part can be fixed by threading the threaded part into a threaded hole in the first pressure plate. In the second fastening part of the fastening device, an outer surface part and a head region can be formed, the outer surface part in particular having a cylindrical shape and the head region in particular having a hexagonal shape. Furthermore, the side part and the head region can have a polygonal shape, for example a triangle, a square or a pentagon. A chamfer can be formed between the head region and the side part of the second fastening part. The chamfer can facilitate the insertion of the side portion of the second fastening portion into a bushing that has a geometrically complementary design.

[0060] The fixing device may include a bushing that can be placed in a corresponding through-hole of the second pressure plate. The through-hole may in particular be designed as a hole, which may in particular have a rounded outer shape. The bushing may in particular be designed as an exchangeable bushing, and in particular may have a tubular shape, which does not necessarily have to be circular, and which has an inner wall and an outer wall with an intermediate surface, which does not necessarily have to be designed as an annular surface. The first end of the bushing may be provided with a chamfer between the surface and the inner wall, which chamfer serves as an insertion aid complementary to the chamfer of the screw mandrel and also facilitates the threading of the side of the screw mandrel during assembly. The second end of the bushing may be placed directly in front of the stiffener plate, where a spatial stop is provided. By means of this spatial stop, the bushing is fixed against movement in its longitudinal direction towards the rear region of the lower chord. The stiffening plate acts like a bulkhead plate and, on the one hand, stiffens the lower chord in the indirect area of ​​the connection between the two lower chords and, on the other hand, seals the lower chord against seepage water and the associated corrosion of the rear area of ​​the lower chord.

[0061] According to a preferred embodiment, in order to accommodate several centering trunnions and several screw mandrels in the same direction, 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 and the other through holes. The same direction of the attached connecting bolts and screw mandrels (preferably parallel to their longitudinal direction) is understood to mean that the connecting bolts and screw mandrels are arranged on the pressure plates in the same direction.

[0062] Thus, at least one other screw mandrel can be provided with a first fastening part for fastening to the second pressure plate of the second cantilever segment and a second fastening part for fastening to the first pressure plate of the first cantilever segment, the first fastening part of the other screw mandrel in particular having a metric thread of standard pitch for fastening to the first pressure plate and the second fastening part of the other screw mandrel having a side part for releasably fastening in the other through hole of the second pressure plate, and a bushing is provided for insertion in the other through hole of the second pressure plate, the bushing having an internal cross-section of a corresponding shape for receiving the side part of the second fastening part of the screw mandrel by way of shape and friction locking. [Brief description of the drawings]

[0063] Further details of the invention will now be explained in more detail with reference to exemplary embodiments shown in the accompanying drawings, in which the same plural references to one part in one and the same figurative expression include both the singular and the plural of each part shown. [Figure 1a] FIG. 1a is a perspective view of an embodiment of an end face of a cantilever segment of a tower crane in an unassembled state. [Figure 1b] FIG. 1b is a perspective view of an embodiment of an end face of a cantilever segment of a tower crane in an unassembled state. [Figure 2a] FIG. 2a is a perspective view of the foot region of two cantilever segments connected using a bottom chord connection according to one embodiment. [Figure 2b] FIG. 2b is a perspective view of the foot region of two cantilever segments connected using a bottom chord connection according to one embodiment. [Figure 2c] FIG. 2c is a perspective view of the foot region of two cantilever segments connected using a bottom chord connection according to one embodiment. [Figure 2d] FIG. 2d is a perspective view of the foot region of two cantilever segments connected using a bottom chord connection according to another embodiment. [Figure 3a] FIG. 3a is a perspective view of a pressure plate according to one embodiment, where the pressure plate is detached from a truss or lattice structure of cantilever segments when viewed from an individual perspective. [Figure 3b] FIG. 3b is a perspective view of a pressure plate according to one embodiment, where the pressure plate is detached from the truss or lattice structure of cantilever segments when viewed from an individual perspective. [Figure 3c] FIG. 3c shows a side view and a perspective view of a pressure plate according to another embodiment, where the pressure plate is detached from the truss or lattice structure of cantilever segments when viewed from an individual perspective. [Figure 4] FIG. 4 is a perspective view of the lower flange connection parts (exploded view) and the two pressure plates that are connected together. [Figure 5a] FIG. 5a is a perspective view of parts of a preferred embodiment lower flange connection and a preferred embodiment pressure plate connected by the lower flange connection. [Figure 5b] FIG. 5b is a perspective view of a part of an alternative embodiment lower flange connection and an alternative embodiment pressure plate connected by a lower flange connection. [Figure 6] FIG. 6 is a cross-sectional view of the assembled bottom chord connection components, bottom chord and pressure plate. [Figure 7] FIG. 7 is a side view and a perspective view of the connecting bolt. [Figure 8] FIG. 8 is a side view and a perspective view of the centering sleeve. [Figure 9] FIG. 9 is a perspective view of the plug-in portion. [Figure 10a] FIG. 10a is an end perspective view of a preferred embodiment of a tower crane cantilever segment in an unassembled state. [Figure 10b] FIG. 10b is an end perspective view of a preferred embodiment of a tower crane cantilever segment in an unassembled state. [Figure 11a]FIG. 11a is a cross-sectional view of the foot region of two cantilever segments connected by a connecting device and a fixing device according to a preferred embodiment. [Figure 11b] FIG. 11b is a cross-sectional view of the assembled parts of the fixing and connecting device according to a preferred embodiment of the bottom chord connection, bottom chord and pressure plate. [Figure 12] FIG. 12 is a cross-sectional view of the assembled parts of a fastening arrangement according to a preferred embodiment of the bottom chord connection, as well as the bottom chord and pressure plate. [Figure 13a] FIG. 13a is a perspective view of a pressure plate according to a preferred embodiment of a bottom chord connection, where the pressure plate is separated from the truss or lattice structure of the individual cantilever segments when viewed from an individual perspective. [Figure 13b] FIG. 13b is a perspective view of a pressure plate according to a preferred embodiment of a bottom chord connection, where the pressure plate is separated from the truss or lattice structure of the individual cantilever segments when viewed from an individual perspective. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0064] 1a, 1b show the connection areas of two embodiments of cantilever segments 1 with an upper chord 2, a terminating upper chord connection 21a and an end face of a pressure plate 5 connecting and terminating a lower chord 3. The illustrated parts of the upper chord connection 21a of a first cantilever segment 1 are connected to complementary parts of the upper chord connection 21b of a second cantilever segment 1b (not shown). At least one lower chord connection with a connection device 4a of the first cantilever segment 1a is mounted on the pressure plate 5 for transportation.

[0065] At least one part of the lower chord connection is located in the foot region of the end face of the cantilever segment 1a and outside the end face 51 of the lower chord 3.

[0066] 2a, 2b, 2c show in different spatial perspectives the foot areas of two cantilever segments 1a, 1b connected to each other by a bottom chord connection device and their integration into a truss or lattice structure of each cantilever segment 1a, 1b. The pressure plates 5a, 5b are arranged with their end faces 53 in direct contact with each other and close to overlap each other at the end face termination 51 (not shown in assembled state) of the bottom chord 3. At least one bottom chord connection of this preferred embodiment is attached to the pressure plate 5a or to the pressure plate 5b and is located spatially close to the bottom chord 3 in the foot area of ​​the cantilever segment 1a, 1b. In figures 2a and 2b the heads of set screws (conventional screws) are shown, which are placed in holes 78 (not shown) in the outer flange surface 75 of the flange 70 of the centering sleeve 7, and by means of which the centering sleeve 7 is screwed into a conventional thread (not shown) located on the mounting side 52 of the pressure plate 5a, thereby fixing it against losses and / or rotation. Figure 2c shows the crown nut 10 and washer 9 as part of the lower chord connection 4 located on the mounting side 52 of the pressure plate 5b.

[0067] Fig. 2d spatially illustrates the foot areas of two cantilever segments 1a, 1b connected to each other by bottom chord connections and their integration into the truss or lattice structure of each cantilever segment 1a, 1b. The pressure plates 5c are arranged with their end faces 53 in direct contact with each other and close the end ends 51 (shown in dashed lines) of the bottom chords 3 overlapping each other. The components of at least one bottom chord connection of this alternative embodiment are arranged on the pressure plates 5c on their mounting sides 52, respectively, and in spatial proximity to the bottom chords 3 in the foot areas of the cantilever segments 1a, 1b.

[0068] 3a shows the pressure plate 5a removed from the truss or lattice structure of each cantilever segment 1b, 1b according to a preferred embodiment. The second through hole 56 of the pressure plate 5a receives a centering sleeve 7 (not shown) in its wall.

[0069] Figure 3b shows the pressure plate 5b removed from the truss or lattice structure of each cantilever segment 1a, 1b according to a preferred embodiment. Each first through hole 54 of the pressure plate 5b is widened at the top by a recess 55. The wall of each first through hole 54 of the pressure plate 5b receives a side surface 63 (second side surface) of a connecting bolt 6 (not shown). The mounting side 52 of the pressure plate 5b is the contact surface for the locking washer 9 (not shown).

[0070] Fig. 3c shows a pressure plate 5c removed from the truss or lattice structure of each cantilever segment 1a, 1b according to another embodiment. The first through hole 54 in the pressure plate 5c is widened at its upper part by a recess 55. The wall of the first through hole 54 in the pressure plate 5c receives the side surface 63 (second side surface) of the connecting bolt 6 (not shown). The wall of the second through hole 56 in the pressure plate 5c receives the centering sleeve 7 (not shown). The mounting side surface 52 of the pressure plate 5c is the contact surface of the locking washer 9 (not shown).

[0071] In Figures 3a, 3b and 3c, the tips 51 are the outer ends of the pressure plates 5a, 5b and 5c, which are located at the tips of the lower chord 3 (not shown).

[0072] 4 shows the parts of the lower chord connection 4a removed from the truss or lattice structure of each cantilever segment 1a, 1b in an unassembled state (exploded view) with the respective pressure plates 5a, 5b or 5c not engaged. A first fastening part of a connection bolt 6 can be inserted into a first through hole 54 and a groove-like extension 55 in the front side 53 of the first pressure plate 5b or 5c and, in subsequent assembly, is screwed into the mounting side 52 of the pressure plate 5b or 5c by means of a threaded part 64 (not shown), a washer 9 and a crown nut 10. The second fastening portion of the connecting bolt 6 can be inserted into the second through hole 56 of the second pressure plate 5a or 5c and, in subsequent assembly, is fixed to the mounting side 52 of the second pressure plate 5a or 5c by means of the centering sleeve 7 inserted into the second through hole 56 of the mounting side 52, the plug portion 8 (not shown) which, in subsequent assembly, is placed in the fixing groove 69, and a spring plug (not shown) which is placed in the fixing hole 84 (not shown) of the plug portion 8 (not shown).

[0073] Figure 5a shows a preferred embodiment with the connection device 4a and the different pressure plates 5a and 5b of the bottom chord connection in the assembled state, removed from the truss or lattice structure of each cantilever segment 1a, 1b. It can be seen that the connection device 4a is attached to each pressure plate 5a and 5b in the same orientation, and each part of the bottom chord connection 4a protrudes from a separate mounting side 52 of the pressure plate 5a. The end faces 53 (not shown) of the pressure plates 5a and 5b are in contact with each other over their entire surface, and the connection of the pressure plates 5a and 5b achieves a high adhesion between their end faces 53 by shape and friction.

[0074] Figure 5b shows another embodiment with the bottom chord connections removed from the truss or lattice structure of each cantilever segment 1a, 1b and two identical pressure plates 5c in the assembled state. It can be seen that the bottom chord connections are attached to each pressure plate 5c in a staggered manner, with parts of the bottom chord connections protruding from each mounting side 52 of the pressure plates 5a and 5c. The end faces 53 (not shown) of the pressure plates 5c are in contact with each other on their entire surfaces, and the connections of the pressure plates 5c achieve a high degree of adhesion due to the shape and friction between their end faces 53.

[0075] 6 shows a cross section of the connection device 4a of the lower chord connection in its mounting position with the pressure plate 5 (of embodiment 5a, 5b or 5c) connected thereby. The end faces 53 of the pressure plates 5 (of embodiment 5a, 5b or 5c) are in contact with each other over their entire surface. The connection bolt 6 is screwed into the first pressure plate 5b or 5c by means of the threaded portion 64 and the attached washer 9 and crown nut 10 of the mounting side 52. A centering pin 613 is placed in the groove-like extension 55 of the first through hole 54 to fix the position of the connection bolt 6 when it is screwed into the first pressure plate 5b or 5c.

[0076] Radially, the centering sleeve 7 receives the outer surface 62 (first outer surface portion) of the connecting bolt 6 on the inner wall 71 of its first sleeve part. Axially, the centering sleeve 7 has a plug portion 8 arranged on the outer flange surface 75 of the second sleeve part.

[0077] The centering sleeve 7 transmits the axial pretension generated by the connecting bolt 6 and the insert portion 8 arranged in the fixing groove 69 to the mounting side 52 of the second pressure plate 5 via its outer flange surface 75 and its inner flange surface 76 by means of the flange surface 70 formed on its second sleeve portion (embodiment 5a or 5c).

[0078] In addition, the centering sleeve 7 transmits the radial pretension transmitted by the connecting bolt 6 through its side surface 62 (first side surface portion) to the wall of the second through hole 56 of the second pressure plate 5 via the inner wall 71 and outer wall 72 of the first sleeve portion (embodiment 5a or 5c).

[0079] 7 shows the details of the connection bolt 6. In particular, the side surface 63 (second side surface) and the side surface 62 (first side surface), as well as the first contact surface 65 and the second contact surface 66, are surfaces that transmit the axial and radial pretension of the lower chord connection portion 4 generated by the connection bolt 6 to the end surface 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).

[0080] FIG. 8 shows the centering sleeve 7 in detail. The tubular first sleeve part of the centering sleeve is bounded by an inner wall 71 and an outer wall 72 and a surface 73 between the inner wall 71 and the outer wall 72, and ends in an undercut 79. The second sleeve part of the centering sleeve starts from the undercut 79 and is an annular peripheral flange 70. The peripheral flange 70 has an outer flange surface 75 and an inner flange surface 76 and a lateral end 77. Holes 78 in the flange 70 receive standard screws (not shown) for fixing the centering sleeve 7 to the mounting side 52 of the pressure plate 5a or 5c. These set screws (not shown) are screwed into the mounting side 52 of the pressure plate 5a or 5c by standard screws in the pressure plate 5a or 5c (not shown) and serve to fix the centering sleeve 7 against losses and / or rotations.

[0081] FIG. 9 shows the plug-in part 8 in detail. In the assembled or plug-in position (not shown), the plug-in part 8 lies in a fixing groove 69 (not shown), which is located on a side surface 61 (third side surface (not shown)) of the conical centering mandrel of the connecting bolt 6 (not shown). One of the contours 82 of the plug-in part 8 is the contact surface with the inner wall 610 (not shown) of the fixing groove 69 (not shown), and the other is the contact surface with the outer flange surface 75 (not shown) of the centering sleeve 7 (not shown). The contour 83 is the contact surface of the plug-in part 8 with the outer wall 611 (not shown) of the fixing groove 69 (not shown) of the connecting bolt 6 (not shown). The contour 81 is the receiving surface for the hammer blow, which is inserted to fix the plug-in part 8 in the fixing groove 69 (not shown) and, if necessary, to readjust the plug-in part 8.

[0082] At least one fastening hole 84 located in the lower region of the plug-in part 8 can receive a spring cotter (standard part, not shown) for fastening the plug-in part 8. When the plug-in part 8 is plugged in and in a set or readjusted position, the at least one fastening hole 84 is located in the space below the fastening groove 69 (not shown) of the connecting bolt 6 (not shown).

[0083] 10a and 10b show the connection area of ​​two cantilever segments 1a, 1b according to a preferred embodiment, each with an upper chord 2, a terminal upper chord connection 21a, 21b and an end face 53 of a pressure plate 5 connecting and terminating a lower chord 3. The illustrated part of the upper chord connection 21a of the first cantilever segment 1a is connected to the complementary part of the upper chord connection 21b of the second cantilever segment 1b. The two fixing devices 4b and the two connecting devices 4a of the first cantilever segment 1a are fixed to the pressure plate 5. Each screw mandrel 40 is arranged at the fixing connection 4b of the foot region of the cantilever segment 1a at the end face termination 51 for each of the lower chords 3. At least one through hole 56 is provided in the pressure plate 5 in the foot region of the cantilever segments 1b and between the end face terminations 51.

[0084] At least one through hole 57 for receiving the screw mandrel 40 is provided in the pressure plate 5 and end face termination 51 in the foot region of the cantilever segment 1b.

[0085] Fig. 11a shows in cross section (top view) the foot region of two cantilever segments 1a, 1b connected to each other by bottom chord connections 4a and 4b according to a preferred embodiment. The pressure plates 5a, 5b are arranged with their end faces 53 in direct contact with each other. The connection device 4a and the fixing device 4b are provided on the pressure plates 5a, 5b and are located close to the space of the bottom chord 3 in the foot region of the cantilever segments 1a, 1b.

[0086] Fig. 11b shows a cross-sectional view (top view) of the foot region of two cantilever segments 1a, 1b connected by a connecting device 4a and a fastening device 4b according to a preferred embodiment, which are provided on pressure plates 5a, 5b and located near the space of the bottom chord 3 in the foot region of the cantilever segments 1a, 1b.

[0087] The fixing device 4b comprises a bushing 45 arranged in a corresponding through hole 57 in the pressure plate 5a, the bushing 45 and the through hole 57 preferably having no play relative to each other, so that one of the bushings 45 is securely mounted in the through hole 57 and the other can be preferably replaced by pulling it out using a bushing puller tool abutted against the inner wall 46 of the bushing 45.

[0088] FIG. 12 shows a cross-sectional view (side view) of two cantilever segments 1a, 1b connected to each other by a fastening device 4b according to a preferred embodiment. The screw mandrel 40 has a threaded portion 41 at the first fastening part. The threaded portion 41 is screwed into a threaded hole 58, which is arranged in the end face termination area 51 of the pressure plate 5b. At the second fastening part, the screw mandrel 40 has a side portion 42 that abuts the threaded portion 41. In the assembled state, the side portion 42 of the screw mandrel 40 is located directly above the end face 53 of the pressure plate 5b and has a secure frictional contact with the inner wall 46 of the bushing 45. A chamfer 44 can be located between the head 43 of the screw mandrel 40 and the side portion 42 of the screw mandrel 40, facilitating the screwing of the screw mandrel 40 into the bushing 45. In particular, the head 43 can be hexagonal in shape to receive a tool, which can be in the form of an open-ended wrench.

[0089] The outer wall 47 of the bushing 45 is in direct contact with the wall of the through hole 57 in the pressure plate 5a. In the assembled state, the bushing 45 is in direct contact with the front face of the stiffener plate 31, which defines its rear end region in the lower chord 3. The rear end region of the bushing 45 is not fixed to either the through hole 57 or the stiffener plate 31, but its outer wall 47 is slightly larger than the diameter of the through hole 57 and is removably mounted within the rear end region by means of a press fit.

[0090] Figure 13a shows the pressure plate 5a removed from the truss or lattice structure of each cantilever segment 1b, 1b according to a preferred embodiment. The through hole 56 in the pressure plate 5a receives the centering sleeve 7 (not shown) in its wall. The through hole 57 in the pressure plate 5a receives the bushing 45 (not shown) in its wall.

[0091] Figure 13b shows the pressure plate 5b removed from the truss or lattice structure of each cantilever segment 1a, 1b according to a preferred embodiment. The through holes 54 of the pressure plate 5b are each widened in their upper region by a recess 55. The walls of the through holes 54 of the pressure plate 5b receive the side surface 63 (second side surface) of the connecting bolt 6 (not shown). The threaded hole 58 of the pressure plate 5b is provided with a metric internal thread (not shown) which receives the metric external thread of the screw mandrel 40 (not shown) which is arranged in the threaded section 41. [Explanation of symbols]

[0092] 1a,1b Cantilever segment 2 Top chord 21a, 21b Upper chord connection 3 Lower Chord 31 Reinforcement plate 4a Connecting device 4b Fixation device 40 Screw mandrel 41 Screw mandrel thread 42 Side of the screw mandrel 43 Head area 44 Chamfered part 45 Bushing 46 Inner wall of bushing 45 47 Outer wall of bushing 45 5 Pressure plate (pressure plate 5a, 5b, 5c) 51 Front end area above the end of the lower chord 52 Mounting side surface of pressure plates 5a, 5b, 5c 53 Front side of pressure plates 5a, 5b, 5c 54 Through holes of pressure plates 5b and 5c 55 Groove-like expansion portion of first through hole 54 56 Second through hole of pressure plate 5a, 5c 57 Through holes in pressure plates 5a and 5c 58 Pressure plate 5b screw hole 6 Connection bolt 61 Sheath surface (cone-shaped) of centering mandrel of connecting bolt (third sheath surface part) 62 Sheath surface of connecting bolt (cylindrical) (second sheath surface part) 63 Sheath surface of connecting bolt (cylindrical) (first sheath surface part) 64 Threaded part 65 First contact surface of connecting bolt 66 Second contact surface of connecting bolt 67 Chamfered section (between sheath section 1 and sheath section 2) 68 Chamfered section (between sheath section 1 and sheath section 2) 69 Fixing groove of centering mandrel of connecting bolt (part 4) 610 Inner wall of fixing groove (contact surface of outer shape 1 of insertion portion 8) 611 Outer wall of fixing groove (contact surface of outer shape 2 of insertion portion 8) 612 Connection bolt side 63 hole 613 Centering pin for positioning the connecting bolt in the center of the groove-like extension 55 7 Centering sleeve 70 Flange (second sleeve part of centering sleeve, collar) 71 Inner wall of the first sleeve portion of the centering sleeve 72 Outer wall of first sleeve portion of centering sleeve 73 Area between the inner wall and the outer wall of the first sleeve part of the centering sleeve 74 Chamfer between the area of ​​the first sleeve portion of the centering sleeve and the inner wall 75: outer flange surface of flange 70, outer contact surface of the second sleeve portion of the centering sleeve (contact surface of the second contact surface of the insert part) 76: Inner flange surface of flange 70, inner contact surface of the second sleeve portion of the centering sleeve (contact surface of the mounting side of the pressure plate) 77 Side end of centering sleeve 78 Hole to accommodate set screw 79 Undercut of first and second sleeve parts of centering sleeve 8 Insertion part 81 Outline of the first contact surface of the insertion part 82 Outline of the second contact surface of the plug 83 Outline of the third contact surface of the plug 84 Fixing hole for receiving spring plug (standard part) 9 Disc (standard part) 10 Crown nut (standard part)

Claims

1. A lower chord connection device having a connection device (4a), in particular for connecting cantilever segments (1) of a cantilever of a tower crane, at least one connecting bolt (6) with a first fastening part (9, 10, 63, 64) for fastening to a first pressure plate (5, 5a, 5b, 5c) of the first cantilever segment (1a) and a second fastening part (61, 62) for fastening to a second pressure plate (5, 5a, 5b, 5c) of the second cantilever segment (1b); said first fastening part (9, 10, 63, 64) comprises removable anti-torsion connection means for fastening to said first pressure plate (5, 5a, 5b, 5c); the second fastening part (61, 62) comprises a centering mandrel for fastening to the second pressure plate (5, 5a, 5b, 5c), the centering mandrel comprising a radial fastening groove (69), in particular a continuous fastening groove, for receiving the insert part (8); a centering sleeve (7) for insertion into a corresponding through hole (54, 56) of said second pressure plate (5, 5a, 5b, 5c), said centering sleeve having an internal cross section for securely receiving said second fastening portion (61, 62); A lower chord connection device having a connection device (4a) comprising:

2. the centering mandrel has a cross section tapering towards the second fastening portion (61, 62) and adjacent to a first cylindrical side cross section; 2. A lower chord connection device having a connection device (4a) according to claim 1, wherein the centering mandrel is, in the assembled state, receivable in the centering sleeve, in a particularly form-fitting manner.

3. A lower chord connection device having a connection device (4a) as described in claim 1 or 2, wherein the centering sleeve (7) has a complete circumferential flange (70) or a partial circumferential flange (70) provided at the axial end of the centering sleeve (7) having flange surfaces (75, 76) and arranged in the assembled state in the direction of the second fastening portion (61, 62).

4. A lower chord connection device having a connection device (4a) as described in claim 3, wherein the flange (70) is provided with flange surfaces (75, 76) and holes (78) by one or more fastening means for fastening in a non-rotating manner to the second pressure plate (5, 5a, 5b, 5c).

5. A lower chord connection device having a connection device (4a) according to any one of claims 1 to 4, wherein the first fastening portion (63, 64) has a second cylindrical side portion which is in particular directly adjacent to the second fastening portion (61, 62).

6. A lower chord connection device having a connection device (4a) as described in claim 5, wherein a screw thread portion (64) is adjacent to a second cylindrical side portion (63) for fixing the first fastening portion (63, 64) to the first pressure plate (5, 5a, 5b, 5c) by a screw.

7. A lower chord connection device having a connection device (4a) according to any one of claims 5 to 6, wherein the second cylindrical shell surface portion (63) is provided with anti-rotation means, said anti-rotation means being formed in particular by a centering pin (613) protruding from said second cylindrical shell surface portion.

8. A lower chord connection device having a connection device (4a) according to any one of claims 1 to 7, wherein the second pressure plate (5, 5a, 5b, 5c) has a continuous second through hole (56) for receiving the centering sleeve (7) in the axial and radial directions by a form and friction fixing method.

9. said first pressure plate (5, 5a, 5b, 5c) comprises a first through hole (54) for receiving the second lateral part (63) in the axial and radial directions by a form and friction fixing manner; A lower chord connection device having a connection device (4a) as described in any one of claims 1 to 8, wherein in an assembled state, the axial end of the first side portion (62) of the second fastening portion (61, 62) abuts against the first pressure plate (5, 5a, 5b, 5c).

10. the first lateral portion (62) has an axial length at least equal to a thickness of the second pressure plate (5, 5a, 5b, 5c); A lower chord connection device having a connection device (4a) as described in claim 9, wherein the fixing groove (69) is provided so that in an assembled state in which the first pressure plate (5, 5a, 5b, 5c) and the second pressure plate abut each other, when the plug portion (8) is inserted, a force is applied to the second pressure plate (5, 5a, 5b, 5c) in the direction of the second fastening portion (61, 62).

11. at least one other connecting bolt (6) has a first fastening part for fastening to the second pressure plate (5, 5a, 5b, 5c) of the second cantilever segment (1b) and a second fastening part for fastening to the first pressure plate of the first cantilever segment (1a); said first fastening parts (63, 64) comprising removable connection means for fastening to said second pressure plate (5, 5a, 5b, 5c); the second fastening part (61, 62) comprises a center mandrel for fastening to the first pressure plate (5, 5a, 5b, 5c), the centering mandrel having a radial fastening groove, in particular a continuous fastening groove, for receiving an insert part (8); A lower chord connection device having a connection device (4a) according to any one of claims 1 to 10, wherein a centering sleeve (7) for insertion into a corresponding through hole of the first pressure plate (5, 5a, 5b, 5c) has an internal cross-section for receiving the second fastening portion (61, 62) in a form-fitting manner.

12. The lower chord connection device connects the two lower chords (3) of the cantilever segments (1a, 1b) to each other; A lower chord connection device having a connection device (4a) described in any one of claims 1 to 11, wherein a fixing device (4b) is provided on the end faces of the two lower chords (3) and fixes the lower chords (3) against lateral displacement in the axial direction of the lower chords (3).

13. The fixing device (4b) at least one screw mandrel (40) having a first fastening portion for fastening to the first pressure plate (5, 5b, 5c) and a second fastening portion for fastening to the second pressure plate (5, 5a, 5c), the second fastening portion has a side portion (42) for attaching the screw mandrel (40) to the second pressure plate (5, 5a, 5c); a bushing (45) for insertion into the through hole (57) of the second pressure plate (5, 5a, 5c); A lower chord connection device having a connection device (4a) as described in claim 12, wherein the bushing (45) has an inner wall (46) that receives the side portion (42) of the second fastening portion.

14. A lower chord connection device having a connection device (4a) as described in claim 13, wherein the first fastening portion has a threaded portion (41) for fastening the screw mandrel (40) to a threaded hole (58) of the first pressure plate (5, 5b, 5c).

15. A lower chord connection device having a connection device (4a) as described in claim 13 or 14, wherein the side portion (42) of the second fastening portion is received in the through hole (57) by a shape and friction fixing method.

Images