Longitudinally dividable truss piece

Abstract

The invention relates to a divisible grid section (10) for a grid boom, comprising two grid section parts (11, 12) that can be detachably connected to one another, which can be detached from one another for transport and can be slid into one another transversely to the longitudinal direction, wherein each of the grid section parts (11, 12) comprises two longitudinally extending corner posts (14) which are firmly connected to one another via several diagonal and vertical bars (15, 16, 17) and together with these define a side surface (30) of the grid section (10), and at least two transverse connection structures (20) that are firmly connected to the corner posts (14), wherein the grid section parts (11, 12) can be detachably connected via connecting means arranged on the transverse connection structures (20).According to the invention, the cross-connection structures (20) each comprise at least two leg bars (21, 22) firmly connected to an upper corner post (14) of a grid section part and at least two leg bars (21, 22) to a lower corner post of the grid section part (11, 12), which together with the respective corner post (14) define an upper and a lower cover surface (31, 32) of the grid section (10), wherein the upper and / or the lower cover surfaces (31, 32) are inclined relative to a plane perpendicular to the side surface (30) towards the other cover surfaces (31, 32) and their leg bars (21, 22) are connected via at least one longitudinal bar (27) running parallel to the corner posts (14) and preferably outside the cover surfaces (31, 32). The invention further relates to a lattice boom (4) with at least one lattice element (10) according to the invention and to a working machine (1) with such a lattice boom (4).

Description

[0001] The present invention relates to a divisible grid element according to the preamble of claim 1, as well as a grid boom and a working machine with such a boom.

[0002] It is known from the prior art to design lattice sections for lattice booms, such as those used as crane booms in mobile cranes, to be divisible into sections in order to provide a wider lattice boom with increased lateral stiffness for crane operation, at least in sections, but to achieve a smaller width for transport in a transport position in order to comply with legal requirements regarding maximum permissible transport dimensions.

[0003] An example of such a divisible grid section is known from DE 10 2017 000 525 A1. The solution presented therein is based on two grid sections with an L-shaped cross-section, whereby one of the grid sections is rotated by 180° to produce a wider grid section. The wider grid section then has an open side that must be closed or bridged by means of separate grid elements. These must therefore be kept separately, which increases storage and assembly costs.

[0004] The present invention is based on the objective of providing a grid element of the generic type, the conversion of which between a widened operating position and a transport position reduced in width requires less assembly effort and in particular has increased stability.

[0005] According to the invention, this problem is solved by a divisible grid element with the features of claim 1. Advantageous embodiments of the invention are described in the dependent claims and the following description.

[0006] According to the invention, a longitudinally divisible grid section for a grid boom is proposed, comprising two grid section parts that can be detachably connected to one another. These parts can be separated for transport and slid into one another transversely to the longitudinal direction to achieve a transport position with a reduced width. Each grid section comprises two longitudinally extending corner posts, which are firmly connected to one another, in particular welded, via several diagonal and vertical bars and, together with the corner posts, define an (imaginary) side surface of the grid section. The grid section also includes at least two transverse connection structures that are firmly connected to the corner posts, in particular welded. Connecting means are located on the transverse connection structures, via which the grid section parts can be detachably connected to one another. In the connected state, these connecting means form the transverse connections of the grid section parts.

[0007] In the assembled grid section (operating state), the cross-connection structures join the side surfaces formed by the corner posts and define the overall width of the assembled grid section ("assembled" here always refers to the operating state of the grid section in which the grid section parts are connected to each other at the connecting elements). This overall width is, in particular, above a predetermined transport width (of, for example, 3.5 meters). The cross-connection structures are designed so that they allow the separated grid section parts to be slid into each other transversely to the longitudinal direction (i.e., in the width direction), thereby reducing the overall width of the grid section in the transport position and thus ensuring compliance with a predetermined transport width (e.g., the overall width in the transport state can be less than 3.5 meters).The cross-connection structures are part of the respective grid components and, in particular, do not represent structures that need to be kept separately, which reduces the assembly effort.

[0008] According to the invention, the cross-connection structures each comprise at least two leg bars rigidly connected to an upper corner post of a lattice section and at least two leg bars rigidly connected to a lower corner post of the lattice section, which together with the respective corner post define an upper and a lower (imaginary) cover surface of the lattice section. The upper cover surface of a cross-connection structure is thus formed in particular by the upper leg bars and the upper corner post, while the lower cover surface is formed by the lower leg bars and the lower corner post.

[0009] According to the invention, the upper and / or lower cover surface of each cross-connection structure is inclined relative to an (imaginary) plane perpendicular to the side surface towards the other cover surface. The upper and / or lower cover surfaces are therefore not perpendicular to the side surface spanned by the corner posts, but run obliquely or inclined, so that the height of the cross-connection structures decreases in the direction of the other lattice section.

[0010] Furthermore, the leg bars are connected to each other via at least one longitudinal bar running parallel to the corner posts to increase the stability of the assembled grid section and reduce the buckling length of the corner posts. The longitudinal bars of the grid section components (each grid section component has at least one such longitudinal bar, preferably two longitudinal bars each, namely one on the lower and one on the upper leg bars) preferably run outside the cover surfaces, i.e., are attached to the outside of the leg bars. The inclination of the upper and / or lower cover surfaces allows the transverse connecting structures to be slid into one another for transport without colliding with the aforementioned longitudinal bars. This provides a grid section with increased stability that is easy to connect and disconnect, and whose transport width can be effectively reduced.

[0011] The longitudinal bars extend along the entire length of the grid components and connect not only the upper and lower leg bars of a cross-connection structure, but all cross-connection structures to each other. This effectively reduces the buckling length of the corner posts.

[0012] The aforementioned side surfaces are spanned in particular by the imaginary central longitudinal axes of the corner posts. The imaginary central longitudinal axes of the diagonal and vertical bars that connect the corner posts of a lattice section also lie, in particular, within the side surface. The upper and lower cover surfaces are spanned in particular by the imaginary central longitudinal axes of the upper and lower leg bars and the upper and lower corner posts.

[0013] Preferably, the corner posts and leg bars, as well as especially the diagonal and vertical bars, are designed as tubes. These may, but do not necessarily have to, have a circular diameter.

[0014] In one possible embodiment, the leg rods are arranged such that the upper and lower cover surfaces each form a triangle. The base of each triangle is formed by a portion of a corner stem. Preferably, leg rods of a cover surface are connected to the corner stem at an acute angle, forming, in particular, an isosceles triangle.

[0015] The cross-connection structures can be designed as prismatic structures (this does not preclude the upper and lower surfaces from not being perfectly parallel to each other), with the upper and lower surfaces each being designed as triangles, in particular as isosceles triangles. The triangles or prismatic structures preferably abut each other directly in the longitudinal direction (i.e., the space between two adjacent cross-connection structures is preferably also triangular (in plan view)), so that a cross-connection structure of the other grid section can be accommodated within it in the transport position.

[0016] In another possible embodiment, the connecting means are arranged at the "tips" of the aforementioned triangles, facing away from the side surfaces. In the assembled state, the tips of the triangular cross-connection structures (as seen from above) are thus arranged side by side and connected to each other via the connecting means. Preferably, connecting means are arranged on both the lower and upper cover surfaces.

[0017] In another possible embodiment, the cross-connection structures have a trapezoidal cross-section or outer contour when viewed longitudinally (i.e., along the corner posts), with the distance between the upper and lower leg bars at the end facing away from the side surface being smaller than the distance between the corner posts. The reduced height of the cross-connection structures at their ends facing away from the side surfaces results from the inclination of the upper and / or lower cover surface. Preferably, both cover surfaces are inclined so that the cross-sections or outer contours of the cross-connection structures form a symmetrical trapezoid when viewed longitudinally. This makes it possible to provide longitudinal bars on the upper and lower cover surfaces and to slide the grid sections together for transport.

[0018] In another possible embodiment, the lattice sections each comprise exactly two cross-connection structures and are preferably connectable to one another at two points (particularly at the apex of the aforementioned triangular or prismatic cross-connection structures) via connecting elements, as seen from a top view. This prevents the lattice section from being statically indeterminate or subjected to stress. A smaller number of components are required for the lattice section, thus reducing its weight. This is particularly advantageous for erecting long boom systems with a main boom. Furthermore, manufacturing costs are reduced because fewer welds are necessary. However, it is of course conceivable to provide more than two (for example, three or four) cross-connection structures per lattice section to form longer lattice sections.

[0019] In another possible embodiment, the longitudinal axes of the leg members of the upper and lower cover surfaces and the longitudinal axes of the respective corner posts intersect. The leg members are therefore not offset from the respective corner posts. The reduced height of the cross-connection structures at their ends facing away from the side surfaces results solely from the inclination of the cover surface(s) and not from an offset of the leg members relative to the corner posts. Consequently, no additional offset moment arises in the corner posts that would need to be considered in structural calculations.

[0020] Preferably, the longitudinal axes of the at least one longitudinal bar and the longitudinal axes of the leg bars connected to it do not intersect. In particular, at least one upper longitudinal bar is arranged above the upper cover surface and at least one lower longitudinal bar is arranged below the lower cover surface and each is connected to the leg bars directly or indirectly via intermediate pieces from the outside, in particular by welding.

[0021] In another possible embodiment, the at least one longitudinal bar is rigidly connected to the respective leg bars via intermediate pieces. If a longitudinal bar is provided on the upper side of the grid section (i.e., above the upper cover surface), then in particular all upper leg bars of the transverse connection structures are rigidly connected to the longitudinal bar via intermediate pieces. If a longitudinal bar is provided on the underside of the grid section (i.e., below the lower cover surface), then in particular all lower leg bars are rigidly connected to the longitudinal bar via intermediate pieces.

[0022] Preferably, the intermediate pieces are designed as elongated hollow profiles whose longitudinal axis runs parallel to the longitudinal axis of the longitudinal bar. The intermediate pieces are preferably designed as "horizontal" pipe sections, i.e., parallel to the longitudinal bar, and preferably with a cross-section that varies along their longitudinal axis (to accommodate the curvatures of the leg bar and longitudinal bar). This allows for longer welds at all connection points, which increases the load-bearing capacity of the connections between the intermediate piece and the longitudinal bar / leg bar. The connections are formed primarily by welding, so that the horizontal arrangement of the intermediate pieces improves accessibility for the welding process and increases the length of the welds.

[0023] The use of a tube as an intermediate piece also offers further advantages over a component manufactured using a different process. The tube can be produced in a single manufacturing step, as the component contour and seam preparations are cut from the raw material in one pass. In particular, it is manufactured from the same raw material and semi-finished products as the rest, or at least large parts, of the lattice structure, especially the longitudinal bar, and is therefore subject to the same requirements regarding manufacturing accuracy, material quality, chemistry, and other specifications.

[0024] In another possible embodiment, only a single longitudinal bar is arranged on each of the upper and / or lower cover surfaces of a grid section. Preferably, exactly one longitudinal bar is provided on the upper cover surface and exactly one longitudinal bar on the lower cover surface. The longitudinal bar preferably runs substantially centrally between the side surface and the ends of the transverse connection structures (on which the connecting elements are arranged) that face away from the side surface. The longitudinal bar may be positioned somewhat closer to the corner post to allow the grid sections to be fully pushed together for transport. The longitudinal bar may run in a central third of the grid section as viewed from above, between the corner post and the connecting element, and in particular in a central fifth.

[0025] The longitudinal bar has a particularly important load-bearing function, as it contributes to the overall stability of the grid section and reduces the buckling length of the corner posts perpendicular to the grid section. The closer the longitudinal bar can be positioned to the central axis of the grid section (i.e., at the ends of the cross-connection structures facing away from the respective side face), the lower the forces to be transmitted and the more delicate the individual connection points of the longitudinal bar to the leg bars (which are preferably realized via the previously described intermediate pieces) can be. The grid section components should be able to be pushed into each other as far as possible during transport. For this, a certain minimum distance between the longitudinal bar and the aforementioned central axis of the grid section is necessary. Therefore, placing the longitudinal bar centrally or essentially centrally on the cross-connection structures offers a good compromise between the stability and transport width of the grid section.

[0026] In another possible embodiment, the connecting means are or comprise fork-finger joints formed by sheet metal structures located at the inner ends of the cross-connection structures opposite the side surfaces. To connect the grid components, the fork-finger joints are slid into one another and bolted together.

[0027] Preferably, the sheet metal structures forming the fork-finger connection points are received and welded into end pieces connected to the leg bars. These end pieces, which are particularly designed as tube sections, can connect the ends of the leg bars facing away from the side surfaces and represent the ends of the cross-connection structures (especially the "tips" of triangular or prismatic cross-connection structures). Preferably, the sheet metal structures are not received in a single recess of the respective end piece, but in two opposing recesses and project through the respective end piece. This results in the sheet metal structures being welded at two points in the end piece and thus being attached much more securely. The recesses can be rectangular.

[0028] The sheet metal structures can penetrate the respective end piece with various cross-sections. Inserting the sheet metal structures for the fork-finger connections of the cross-connections of the grid section results in the load being distributed across two circumferential welds instead of a single circumferential weld. This offers advantages in manufacturing and structural design.

[0029] In another possible embodiment, the corner posts are rigidly connected to each other at their ends via posts, and between the posts via a plurality of diagonal and zero-bars. The posts and zero-bars each represent vertical bars (defined here as bars whose longitudinal axes run perpendicular to the longitudinal axes of the corner posts), with the posts longitudinally bounding the side surfaces transmitting forces from the longitudinal connections of the grid section to adjacent grid sections, while the zero-bars arranged between the posts do not transmit any forces. The corner posts, posts, diagonal bars, and zero-bars span the side panels or surfaces of the grid section, in particular as a planar supporting structure.

[0030] Preferably, a zero-bar is always arranged between two adjacent diagonal bars, so that the diagonal and zero-bars alternate. The zero-bars reduce the buckling length of the corner posts in the direction of the side faces from one diagonal bar to the next.

[0031] In another possible embodiment, the cross-connection structures are provided for by comprising several diagonal and vertical bars to increase their stability. The upper leg bars forming the upper cover surface and the lower leg bars forming the lower cover surface of a cross-connection structure are rigidly connected to each other via several diagonal and vertical bars. These vertical bars can include zero-force bars and / or posts (which transmit forces from the cross-connections between the grid sections). In the case of triangular cover surfaces, the upper and lower leg bars can be connected to each other at the "apexes" of the triangles via a post.

[0032] The buckling length of the leg members is reduced by adding zero-weight members (the buckling length is halved when placed centrally). One zero-weight member and one diagonal member can be provided on each side of a cross-connection structure (which is spanned by an upper and lower leg member). This results in stable, planar structures that form the sides of the cross-connection structures.

[0033] Preferably, the leg members are firmly connected to the corner posts via additional diagonal members whose longitudinal axes lie within the upper or lower cover surface. These reduce the buckling length of the leg members.

[0034] In another possible embodiment, at least one of the grid sections comprises retaining connectors with which the connectors of the other grid section can be detachably connected in a transport position where the grid sections are nested. The retaining connectors can be fork-finger connections or can include fork-finger connections that can be connected to corresponding fork-finger connections of the other connectors via bolts. This allows the two grid sections to be connected or locked together in the nested transport position, preventing them from unintentionally separating.

[0035] In another possible embodiment, the retaining connecting means are arranged at the ends of the corner posts or at the ends of posts connecting the corner posts. Preferably, the transverse connection structures are designed and the connecting and retaining connecting means are arranged such that the grid sections, in a state where they have a connection between connecting and retaining connecting means only at one end, can be pivoted into one another about a pivot axis formed by this retaining connection in order to pivot the connecting and retaining connecting means together at the opposite end.

[0036] This results in a simplified assembly and disassembly process. To reconfigure the grid section for transport, it may be necessary to move only one of the grid sections while the other remains stationary. Any lifting equipment used for this purpose (e.g., an assembly crane) can be attached to lifting points on the upper corner post of one of the grid sections and lift this section to relieve the load on the connecting elements at the cross-connections between the grid sections.After the bolts have been pulled (in the case of a fork-finger connection), the attached (first) grid section is moved away from the other (second) grid section and completely lifted and moved relative to the second grid section so that the connecting elements of the first grid section overlap with the holding connecting elements of the second grid section at one end and a first holding connection can be established (in particular by bolting).

[0037] After the first locking connection is closed, the raised first mesh section is pivoted by the lifting device around the pivot axis formed by the first locking connection to the stationary mesh section, and the second locking connection is established. This eliminates the need for personnel to enter the mesh section to close it (form and lock it into the transport position), as the connection points of the locking connections are accessible on the end faces of the transport unit (i.e., the mesh section in the transport position). Furthermore, being able to close the locking connections sequentially is more convenient than having to align all the connecting and locking devices simultaneously.

[0038] The invention further relates to a lattice boom with a lattice section according to the invention. The lattice boom can comprise several lattice sections according to the invention. These can be connected to one another via longitudinal connecting means arranged on the corner posts, which can be designed as fork-finger connection points.

[0039] The invention further relates to a working machine with a lattice boom according to the invention. This machine can be a crane, in particular a mobile crane such as a crawler crane. The working machine preferably comprises an undercarriage with a chassis, in particular a crawler chassis, and a superstructure rotatably mounted on the undercarriage about a vertical axis of rotation. The lattice boom according to the invention is mounted on the superstructure so as to be rockable about a horizontal pivot axis. The working machine can also have a derrick boom mounted on the superstructure. Preferably, the lattice boom according to the invention forms the main boom of the working machine. Further attachments, for example a fixed jib, can be mounted on this main boom.

[0040] Further features, details and advantages of the invention will become apparent from the exemplary embodiments explained below with reference to the figures. The figures show: Fig. 1: A perspective view of an embodiment of the grid piece according to the invention in the assembled state; Figs. 2-3: Side views of the grid piece; Fig. 4: A connecting element of the grid piece in a perspective view; Fig. 5: A side sectional view of two bolted connecting elements of the grid piece; Fig. 6: A perspective view of the grid piece in the transport position; Fig. 7: A perspective view of the grid piece when the grid piece parts are pivoted together; Fig. 8: A side sectional view of the lower and upper retaining connections in the bolted state; Fig. 9: A perspective view of an intermediate piece; and Fig. 10: A side view of a machine according to the invention in an embodiment.

[0041] The Figure 1Figure 1 shows an embodiment of the divisible grid element 10 according to the invention in a perspective view. The grid element 10 comprises two grid element parts 11, 12, which can be detachably connected to one another via several connecting means 26 and which can also be referred to as grid element halves. The two grid element parts 11, 12 preferably have a symmetrical structure (with respect to an imaginary central plane extending in the longitudinal direction). A side view with a viewing direction along the longitudinal axis of the grid element 10 is shown in Figure 1. Figure 2 depicted.

[0042] Each grid section 11, 12 comprises two corner posts 14, which extend longitudinally along the grid section 10 and may be designed as hollow profiles. The corner posts 14 may have longitudinal connecting elements 13 at their end faces in the form of fork-finger connections, via which the grid section 10 can be bolted to further grid sections 10 according to the invention and / or to other grid sections. The corner posts 14 are firmly connected to one another by a plurality of diagonal bars 17 and vertical bars 15, 16 extending perpendicular to the corner posts 14. Two posts 15 may be provided as vertical bars, connecting the corner posts 14 to one another in the area of ​​the longitudinal connecting elements 13 and transmitting forces from these fork-finger connections. Several zero-point bars 16 may also be provided as vertical bars, arranged between the diagonal bars 17.

[0043] As in the Figure 3As indicated, the imaginary longitudinal axes of the corner posts 14 and the diagonal and vertical bars 15, 16, 17 lie in a common plane and span an imaginary side surface 30 of the grid piece 10.

[0044] The lattice sections 11, 12 each comprise several cross-connection structures 20, on which the connecting means 26 for the cross-connections are arranged. In the illustrated embodiment, the cross-connection structures 20 form prismatic truss structures with a triangular base. The cross-connection structures 20 each comprise two lower leg members 21, which are rigidly connected to the lower corner post 14, and two upper leg members 22, which are rigidly connected to the upper corner post 14. The lower leg members 21 of a cross-connection structure 20 extend at an acute angle to the lower corner post 14 and converge at a point facing away from the side surface 30, so that their longitudinal axes and the longitudinal axis of the lower corner post 14 form an imaginary lower cover surface 31 (cf. Fig. 3Similarly, upper leg bars 22 of a transverse connection structure 20 run at the same acute angle to the upper corner stem 14 and converge at a point facing away from the side surface 30, so that their longitudinal axes and the longitudinal axis of the upper corner stem 14 form an imaginary upper cover surface 32 (cf. Fig. 3 ). The upper and lower cover surfaces 31, 32 are triangular and congruent in this embodiment.

[0045] As in the Figure 2As can be seen, the connecting elements 26, which form the detachable cross-connections of the grid section parts 11, 12, are arranged at the "tips" of the prismatic cross-connection structures 20 formed by the upper and lower leg bars 21, 22. The grid section 10 of this embodiment has exactly two cross-connection structures 20 per grid section part and thus a total of four connecting elements 26 (at two different positions in the top view). However, more than two cross-connection structures 20 per grid section part 11, 12, or more than four connecting elements 26, could be provided.

[0046] On each side face of the prismatic structure, the cross-connection structures 20 also have diagonal and vertical bars 23, 24, 29, which firmly connect the lower and upper leg bars 21, 22 to each other on each side (cf. Fig. 3A post 29 can connect the tips of the upper and lower leg members 21, 22 in the area of ​​the connecting elements 26. A further zero-profile member 23 can be provided essentially centrally on the side surfaces of the cross-connection structures 20. On each side of the zero-profile member 23, a diagonal member 24 can connect the lower and upper leg members 21, 22 to each other. This results in truss-like side surfaces of the cross-connection structures 20, which gives them greater stability and reduces the buckling lengths of the leg members 21, 22.

[0047] The upper leg bars 22 of two interconnected cross-connection structures 20 of the connected grid piece 10 can run coaxially, as can the respective lower leg bars 21. As in the Figure 1As can be seen, the upper leg bars 22 (and correspondingly the lower leg bars 21) of the connected grid piece 10 thereby form, in particular, an "X" or, in the case of two cross-connection structures 20, two adjacent "X"s per grid piece part 11, 12. This can result in a gap with a square base (in plan view) in the middle of the connected grid piece 10.

[0048] As in the Figure 1 As can be further seen, the upper leg bars 22 can be connected to the upper corner post 14 via further diagonal bars 25, whose longitudinal axes run within the upper cover surface 32, in order to reduce the buckling length of the leg bars 22 within this plane, and analogously the lower leg bars 21.

[0049] Each grid section 11, 12 can comprise two longitudinal bars 27 extending parallel to the corner posts 14 and firmly connected to the leg bars 21, 22 to reduce the buckling length of the corner posts 14 and increase the stability of the grid section 10. An upper longitudinal bar 27 preferably runs above the upper cover surface 32 and is connected to the upper leg bars 22 via end pieces 38 described in more detail below (see Figure 1). Fig. 2 ). A lower longitudinal bar 27 preferably runs below the lower cover surface 31 and is also connected to the lower leg bars 21 via end pieces 38 (see figure). Fig. 2 Alternatively, several upper and lower longitudinal bars 27 could be provided.

[0050] The longitudinal bars 27 are preferably arranged approximately in the middle between the side surfaces 30 and the imaginary central plane of the grid piece 10, which runs through the connecting means 26.

[0051] To comply with the legally prescribed transport dimensions, in particular a maximum transport width, the grid section 10 can be longitudinally split at the central connecting elements 26, i.e., the two grid section parts 11, 12 can be separated from each other. Due to the shape of the transverse connecting structures 20, the grid section parts 11, 12 can be offset from each other longitudinally and slid into one another transversely, so that the transverse connecting structures 20 of the different grid section parts 11, 12 are nested and interlocked. Such a transport condition is in the Figure 6 depicted.

[0052] To enable such an interlocking motion despite the longitudinal bars 27, the upper and lower leg bars 21, 22 are not parallel to each other, but are slightly inclined towards each other. In other words, the upper and lower cover surfaces 31, 32 are not perpendicular to the side surface 30, but are slightly inclined towards each other (cf. Fig. 2-3 ). This means that the distance between the upper and lower leg bars 21, 22 at the tips of the cross-connection structures 20 is less than the distance between the corner posts 14. This makes it possible to slide the cross-connection structures 20 into each other to form the transport position despite the longitudinal bars 27.

[0053] Alternatively to the one in Fig. 3 In the illustrated embodiment, a longitudinal rod 27 could be arranged on only one of the cover surfaces, and only this cover surface could be inclined, while the other cover surface would be perpendicular to the side surface 30. Alternatively, both cover surfaces 31, 32 could be inclined at different angles. However, a configuration like that shown is preferred. Fig. 3 , in which the lateral cross-sections of the cross-connection structures form 20 symmetrical trapezoids.

[0054] In the Figure 4Figure 1 shows the tip of a cross-connection structure 20 with the associated connecting element 26. The latter can be designed as a fork-finger connection (in the example of the Fig. 4 as a fork, wherein the corresponding connecting element 26 of the other grid section is designed as a finger), which is formed by a corresponding sheet metal structure. The ends of the (here upper) leg bars 22 facing away from the side surface 30 are connected to each other via a preferably tubular end piece 38. In the Figure 5 Two bolted connecting elements 26 of the two grid section parts 11, 12 are shown in a side view as a section through the connecting elements 26. These are shown bolted together by a bolt 34.

[0055] The end piece 38 has a first recess facing the connecting element 26 of the other grid section when assembled, and a second recess facing the side surface 30. The sheet metal structure forming the connecting element 26 is inserted through both recesses and extends through the end piece (see figure). Fig. 5 This means that the sheet metal structure of the connecting element 26 is welded to the end piece 38 not only at one recess, but at two recesses, and is therefore more securely attached to the end piece. In particular, the sheet metal structure is welded to the end piece 38 at the front recess with a circumferential front weld 50 and at the rear recess with a circumferential rear weld 51.

[0056] All bars or tubes 14, 15, 16, 17, 21, 22, 23, 24, 25, 28, 38 of a grid section 11, 12 are preferably welded together.

[0057] The grid sections 11, 12 can comprise several retaining connecting means 36 with which the connecting means of the other grid section 11, 12 can be connected in the transport position in order to secure or lock the grid sections 11, 12 in the transport position. Preferably, the retaining connecting means 36, like the connecting means 26, are fork-finger connection points.

[0058] The Figure 7 Figure 1 shows an embodiment in which each grid section 11, 12 has two retaining connecting elements 36 at one longitudinal end, which are arranged in the region of the ends or longitudinal connecting elements 13 of the corner posts 14. The retaining connecting elements 36 can be connected to the corner posts 14 or to a post 15 therein, or to both, in particular by welding.

[0059] It may be provided that only the connecting means 26 of one of the cross-connection structures 20 are connected to the holding connecting means 36 of the other grid section part 11, 12 (cf. Fig. 7 ).

[0060] The connecting means 26 and retaining connecting means 36 are bolted together, in particular. Preferably, the same bolts 34 are used for this purpose as for connecting the connecting means 26 to each other. In the connected state, the bolts 34 are arranged, in particular, coaxially to each other (one above the other) and form a pivot axis 37 about which the two grid section parts 11, 12 can be pivoted, as long as they are only connected at one end. Figure 7 The situation is shown in which the grid section parts 11, 12 are bolted together only at one of their ends via the connecting means 26 and holding connecting means 36 and can pivot to each other about the pivot axis 37 formed by this first holding connection.

[0061] One of the grid pieces 11, 12 (for example in the Fig. 7 The first grid section 11 shown on the right can be lifted by an assembly crane and pivoted around the pivot axis 37 towards the other, second grid section 12, so that the cross-connection structures 20 interlock. The grid sections 11, 12 can have several lifting points 18 on the corner posts 14 for lifting by an assembly crane (see figure). Fig. 1 ). As soon as the connecting means 26 and retaining connecting means 36 overlap at the other end of the grid section parts 11, 12, these can be bolted together and thus the second retaining connection can be made.

[0062] The Figure 8Figure 1 shows a section through the upper and lower retaining fasteners 36 of one end of a grid section 11, 12 transversely to the longitudinal direction, with the section of the grid section 11, 12 in between not shown. It can be seen that the bolts 34 are arranged coaxially.

[0063] Preferably, corresponding bolt-in devices are arranged between the connecting elements 26 on the transverse connection structure 20, which carries the connecting elements 26 that can be bolted to the retaining connecting elements 36. These devices can be connected to a post 29 that connects the upper and lower leg bars 21, 22. The bolt-in devices can include actuators (not shown) that allow movement of the bolts 34 to release or insert the transverse or retaining connections. The bolts 34 can accordingly be connected to rods that, in turn, can be moved along the imaginary pivot axis 37 via the aforementioned actuators. This eliminates the need for human personnel to manually insert or release the bolts 34, which significantly simplifies the assembly and disassembly process.

[0064] The Figure 9Figure 1 shows an intermediate piece 28, via which the upper longitudinal bar 27 of a lattice section 11, 12 is connected to an upper leg bar 22. The intermediate piece 28 is preferably designed as a tube section whose longitudinal axis 43 runs parallel to the longitudinal axis 42 of the longitudinal bar 27. This parallel arrangement of the tubular intermediate piece 28 allows for longer welds at the connection points to the leg bar 22 and the longitudinal bar 27, respectively, and its accessibility is also improved compared to tube sections positioned perpendicular to the longitudinal and leg bars 22, 27. Fig. 9 As shown, the cross-section of the intermediate piece 28 can vary along its longitudinal axis 43 in order to adapt its contour to the curvatures of leg bar 22 and longitudinal bar 27.

[0065] Furthermore, it shows Fig. 9, that by using intermediate pieces 28 the longitudinal bars 27 do not run within the respective cover surfaces 31, 32, but above them (or below them on the lower cover surface 31). Thus, the longitudinal axes 42 of the longitudinal bars 27 do not intersect the longitudinal axes 41 of the leg bars 21, 22.

[0066] The Figure 10 Figure 1 shows a side view of an embodiment of the machine 1 according to the invention, which comprises a boom 4 with one or more grid sections 10 according to the invention. In the working machine of the embodiment of the Figure 10The crane is a crawler crane 1 with an undercarriage 2 with crawler tracks and a superstructure 3 mounted on the undercarriage 2 so as to be rotatable about a vertical axis of rotation. The boom 4 is pivotally attached to the superstructure about a horizontal luffing axis. The boom 4 is the main boom and can support a fixed jib 5. The crawler crane 1 can have a derrick boom 6 and a derrick ballast 7. Reference symbol list:

[0067] 1 Working machine 2 Undercarriage 3 Superstructure 4 Boom 5 Fixed jib 6 Derrick boom 7 Derrick ballast 10 Lattice section 11 First lattice section 12 Second lattice section 13 Longitudinal connector 14 Corner post 15 Post 16 Zero bar 17 Diagonal bar 18 Anchor point 20 Transverse connection structure 21 Lower leg bar 22 Upper leg bar 23 Zero bar 24 Diagonal bar 25 Diagonal bar 26 Connector 27 Longitudinal bar 28 Intermediate piece 29 Post 30 Side face 31 Lower cover face 32 Upper cover face 34 Bolt 36 Holding connector 37 Swivel axis 38 End piece 41 Longitudinal axis leg bar 42 Longitudinal axis longitudinal bar 43 Longitudinal axis intermediate piece 50 Front weld 51 Rear weld

Claims

1. Longitudinally divisible grid section (10) for a grid boom, comprising two grid section parts (11, 12) that can be detachably connected to one another, which can be detached from one another for transport and slid into one another transversely to the longitudinal direction, wherein each of the grid section parts (11, 12) comprises two longitudinally extending corner posts (14) which are firmly connected to one another via several diagonal and vertical bars (15, 16, 17) and together with these define a side surface (30) of the grid section (10), and at least two transverse connection structures (20) that are firmly connected to the corner posts (14), wherein the grid section parts (11, 12) can be detachably connected via connecting means (26) arranged on the transverse connection structures (20), characterized by thatthe cross-connection structures (20) each comprise at least two leg bars (21, 22) firmly connected to an upper corner post (14) of a grid section part (11, 12) and at least two leg bars (21, 22) connected to a lower corner post (14) of the grid section part (11, 12), which together with the respective corner post (14) define an upper and a lower cover surface (31, 32) of the grid section (10), wherein the upper and / or the lower cover surfaces (31, 32) are inclined relative to a plane perpendicular to the side surface (30) towards the other cover surfaces (31, 32) and their leg bars (21, 22) are connected via at least one longitudinal bar (27) running parallel to the corner posts (14) and preferably outside the cover surfaces (31, 32).

2. Grid piece (10) according to claim 1, wherein the leg bars (21, 22) are arranged such that the upper and lower cover surfaces (31, 32) form triangles, wherein preferably both leg bars (21, 22) of a cover surface (31, 32) are connected at an acute angle to the corner stem (14) and in particular form an isosceles triangle.

3. Grid piece (10) according to claim 2, wherein the connecting means (26) are arranged at the tips of the triangles facing away from the side surfaces (30), wherein connecting means (26) are preferably arranged at both the lower and the upper cover surfaces (31, 32).

4. Grid piece (10) according to one of the preceding claims, wherein the transverse connection structures (20) have a trapezoidal cross-section viewed in the longitudinal direction, wherein the distance between the leg bars (21, 22) of the upper and lower cover surfaces at the ends facing away from the side surface (30) is less than the distance between the corner posts (14), wherein the cross-sections preferably form a symmetrical trapezoid.

5. Grid piece (10) according to one of the preceding claims, wherein the grid piece parts (11, 12) comprise exactly two transverse connection structures (20) and are preferably connectable to each other at two points via connecting means (26) in a top view.

6. Lattice piece (10) according to one of the preceding claims, wherein the longitudinal axes (41) of the leg bars (21, 22) of the upper and lower cover surfaces (31, 32) and the longitudinal axes of the respective corner posts (14) intersect, wherein the longitudinal axis (42) of the at least one longitudinal bar (27) and the longitudinal axes (41) of the leg bars (21, 22) preferably do not intersect.

7. Grid piece (10) according to one of the preceding claims, wherein the at least one longitudinal bar (27) is firmly connected to the respective leg bars (21, 22) via intermediate pieces (28), wherein the intermediate piece (28) is preferably designed as an elongated hollow profile, the longitudinal axis (43) of which runs parallel to the longitudinal axis (42) of the longitudinal bar (27) and the cross-section of which varies in particular along its longitudinal axis (43).

8. Grid piece (10) according to one of the preceding claims, wherein only a single longitudinal bar (27) is arranged on the upper and / or lower cover surfaces (31, 32) of a grid piece part (11, 12), which preferably runs substantially centrally between the side surface (30) and the ends of the cross-connection structures (20) facing away from the side surface (30).

9. Grid piece (10) according to one of the preceding claims, wherein the connecting means (26) comprise fork-finger connection points formed by sheet metal structures arranged at the inner ends of the transverse connection structures (20) opposite the side surfaces (30) and in particular received and welded in end pieces (38) connected to the leg bars (21, 22), wherein preferably the sheet metal structures are received in two opposite recesses of the end pieces (38) and project through the end pieces (38).

10. Lattice piece (10) according to one of the preceding claims, wherein the corner posts (14) are firmly connected to each other at the ends via posts (15) and between the posts (15) via a plurality of diagonal and zero bars (16, 17), wherein the diagonal and zero bars (16, 17) preferably alternate.

11. Grid piece (10) according to one of the preceding claims, wherein the upper leg bars (22) forming the upper cover surface (32) and the lower leg bars (21) forming the lower cover surface (31) of a transverse connection structure (20) are firmly connected to each other via several diagonal and vertical bars (23, 24), wherein the leg bars (21, 22) are preferably firmly connected to the corner posts (14) via additional diagonal bars (25) whose longitudinal axes lie within the upper and lower cover surfaces (31, 32), respectively.

12. Grid piece (10) according to one of the preceding claims, wherein at least one of the grid piece parts (11, 12) comprises retaining connecting means (36) with which connecting means (26) of the other grid piece part (11, 12) can be detachably connected in a transport position in which the grid piece parts (11, 12) are pushed into one another, wherein preferably both grid piece parts (11, 12) each comprise at least two retaining connecting means (36).

13. Grid piece (10) according to the preceding claim, wherein the retaining connecting means (36) are arranged at the ends of the corner posts (14) or at the ends of the posts (15) connecting the corner posts (14), wherein preferably the transverse connection structures (20) are designed and the connecting means (26) and retaining connecting means (36) are arranged such that the grid piece parts (11, 12) in a state in which they have a connection between connecting means (26) and retaining connecting means (36) only at one end are pivotable into each other about a pivot axis formed by this connection in order to pivot the connecting means (26) and retaining connecting means (36) together at the other end.

14. Lattice boom (4) with at least one lattice section (10) according to one of the preceding claims.

15. Working machine (1), in particular crane, with a lattice boom (4) according to the preceding claim, wherein the working machine (1) preferably comprises a chassis (2) with a running gear, in particular crawler running gear, a superstructure (3) rotatably mounted on the chassis (2) about a vertical axis of rotation and the lattice boom (4) is mounted on the superstructure (3) so as to be rockable about a horizontal pivot axis.

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