BOX GIRDER, IN PARTICULAR CRANE GIRDER, AND CRANE HEREWITH AS WELL AS MANUFACTURING METHOD THEREFOR

Abstract

A box girder configured as a crane girder has two side plates spaced apart from each other, at least one chord plate connecting the two side plates to each other and at least one transverse plate arranged between the side plates and connecting the side plates to each other, with a welded joint provided between the respective chord plate and the side plates. In order to facilitate the manufacturing process of the box girder, at least one form-fitting connection configured as a plug-in connection is provided between the transverse plate and each of the two side plates. A crane may thus be configured having such a box girder. A corresponding method of manufacturing may also be employed for forming the box girder.

Claims

1.-12. (canceled)

13. A box girder configured as a crane girder, the box girder comprising: two side plates spaced apart from each other; at least one chord plate connecting the two side plates to each other; and at least one transverse plate that is arranged between the side plates and that connects the side plates to each other; wherein a welded joint is provided between the respective chord plate and the side plates, and wherein at least one form-fitting connection comprising a plug-in connection is provided between the transverse plate and each of the two side plates, and wherein at least one form-fitting connection comprising a plug-in connection is also provided between the transverse plate and the chord plate.

14. The box girder as claimed in claim 13, wherein the respective form-fitting connection comprises a plug-in portion of the transverse plate that is received by a corresponding receiving aperture of the respective side plate and/or the respective chord plate, with each receiving aperture having a substantially complementary shape relative to the respective plug-in portion.

15. The box girder as claimed in claim 14, wherein the plug-in portion is formed as a protrusion of an outer edge of the transverse plate, and wherein the protrusion has a rectangular shape.

16. The box girder as claimed in claim 15, wherein at least one of the plug-in portions is designed to form a support element extending through the corresponding receiving aperture, with the support element being configured to attachably receive a crane equipment element comprising a power supply line and/or a platform for personnel.

17. The box girder as claimed in claim 16, further comprising a force-transmitting connection comprising a further welded joint provided between the transverse plate and the respective side plate and/or between the transverse plate and the respective chord plate, wherein the further welded joint comprises a fillet or a plug weld type.

18. The box girder as claimed in claim 17, wherein the at least one chord plate comprises two chord plates, and wherein each chord plate can alternatively form an upper chord in a first orientation of the box girder or a lower chord in a second orientation of the box girder, and wherein, independently from the orientation of the box girder, a running surface for wheels of a crane trolley is provided on the same chord plate.

19. The box girder as claimed in claim 14, wherein the plug-in portion is formed as a protrusion of an outer edge of the transverse plate.

20. The box girder as claimed in claim 19, wherein the protrusion has a rectangular shape.

21. The box girder as claimed in claim 14, wherein at least one of the plug-in portions is designed to form a support element extending through the corresponding receiving aperture, with the support element configured to attachably receive a crane component.

22. The box girder as claimed in claim 13, further comprising a force-transmitting connection comprising another welded joint provided between the transverse plate and the respective side plate and/or between the transverse plate and the respective chord plate.

23. The box girder as claimed in claim 13, wherein the at least one chord plate comprises two chord plates with one chord plate disposed at one end of the side plates and the other chord plate disposed at an opposite end of the side plates

24. The box girder as claimed in claim 23, wherein each chord plate can alternatively form an upper chord in a first orientation of the box girder or a lower chord in a second orientation of the box girder, and wherein, independently from the orientation of the box girder, a running surface for wheels of a crane trolley is provided on the same chord plate.

25. A crane having a box girder and a lifting gear that is arranged on the box girder, wherein the box girder comprises: two side plates spaced apart from each other; two chord plates comprising an upper chord and a lower chord connecting the two side plates to each other; and at least one transverse plate that is arranged between the side plates and that connects the side plates to each other; wherein a welded joint is provided between the respective chord plate and the side plates, and wherein at least one form-fitting connection comprising a plug-in connection is provided between the transverse plate and each of the two side plates, and wherein at least one form-fitting connection comprising a plug-in connection is also provided between the transverse plate and the chord plate, and wherein the lifting gear is movable along the box girder and on its upper chord or lower chord by means a crane trolley.

26. The crane as claimed in claim 25, wherein the respective form-fitting connection comprises a plug-in portion of the transverse plate that is received by a corresponding receiving aperture of the respective side plate and/or the respective chord plate, with each receiving aperture having a substantially complementary shape relative to the respective plug-in portion.

27. The box girder as claimed in claim 25, wherein the plug-in portion is formed as a protrusion of an outer edge of the transverse plate.

28. The box girder as claimed in claim 25, wherein at least one of the plug-in portions is designed to form a support element extending through the corresponding receiving aperture, with the support element configured to attachably receive a crane component.

29. The box girder as claimed in claim 25, further comprising a force-transmitting connection comprising another welded joint provided between the transverse plate and the respective side plate and/or between the transverse plate and the respective chord plate.

30. A method of manufacturing a box girder configured as a crane girder, said method comprising: spacing two side plates apart from each other; arranging at least one transverse plate between the side plates; and connecting the two side plates to each other with the at least one transverse plate and with at least one chord plate, wherein said connecting the two side plates to each other includes at least one form-fitting connection comprising a plug-in connection between the transverse plate and each of the two side plates, and includes at least one form-fitting connection comprising a plug-in connection between the transverse plate and the chord plate; and welding a joint between the respective chord plate and the side plates after said connecting the two side plates to each other.

31. The method of manufacturing a box girder as claimed in claim 30, wherein the respective form-fitting connection is produced by plugging a plug-in portion of the transverse plate into a corresponding receiving-aperture of the respective side plate and/or the respective chord plate, each receiving aperture having a substantially complementary shape relative to the respective plug-in portion.

32. The method of manufacturing a box girder as claimed in claim 30, further comprising welding a force-transmitting connection comprising a further welded joint between the transverse plate and the respective side plate and/or between the transverse plate and the respective chord plate, wherein the further welded joint comprises a fillet or a plug weld type.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1a shows a perspective view of a section of a box girder, in particular a crane girder, in accordance with an embodiment of the invention;

[0036] FIG. 1b shows a side view of the box girder of FIG. 1a;

[0037] FIG. 2a shows a front view of the box girder of FIGS. 1a and 1 b in a first orientation and as seen in the direction of the longitudinal extension of the girder;

[0038] FIG. 2b shows a front view of the box girder of FIGS. 1a and 1b in a second orientation and as seen in the direction of the longitudinal extension of the girder;

[0039] FIG. 3a shows a plan view of a first embodiment of a transverse plate of the box girder of FIGS. 1a, 1b, 2a and 2b; and

[0040] FIG. 3b shows a plan view of a second embodiment of a transverse plate of the box girder of FIGS. 1a, 1b, 2a and 2b.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] FIG. 1a shows a perspective view of a section of a box girder 1 that is configured to be used as a crane girder, e.g. for a single-girder crane or a double-girder crane. If a crane is designed as a double-girder crane, the crane does not only comprise one single box girder 1 but two corresponding box girders 1 according to the invention that are then arranged in parallel to each other. The features that are described regarding the box girder 1 apply accordingly to both girders in case of a double-girder crane.

[0042] The girder 1 is oriented horizontally with its longitudinal extension L. When used as a crane girder, the girder 1 is configured to support a crane trolley having a lifting gear, e.g. a cable winch or a chain hoist. The crane trolley, in particular its traveling mechanism and the lifting gear, is motorized, e.g. by means of at least one electric drive motor. The motorized crane trolley is thus movable together with the lifting gear along the longitudinal extension L of the girder. For this purpose a running surface 7 for wheels 6 (see FIGS. 2a and 2b) of the crane trolley is provided on the girder 1. Furthermore, provision may be made that traveling mechanisms, not illustrated, are fastened to opposite ends of the girder 1, so that a crane bridge is formed. By means of the traveling mechanisms of the girder 1, the girder 1 is movable on rails, not illustrated, in a horizontal direction of travel transversely and at right angles with respect to the longitudinal extension L of the girder 1. The rails are typically arranged at a position above the ground and for this purpose can be elevated, for example, by means of a suitable support structure or can be fastened to opposite walls of a building. In order to move the girder 1, the traveling mechanisms of the girder 1 are each driven by a drive motor, in particular by an electric motor. By means of a crane control horizontal movements of the girder 1 and/or the crane trolley together with the lifting gear and vertical movements of the lifting gear can be controlled and operated separately from one another in order to pick up and move loads between different places and in three-dimensional moving directions.

[0043] In case of a so-called top running crane trolley application the running surface 7 for the crane trolley may be provided on top of the girder 1, especially on its upper chord 3 that may also be designated as a top flange or by a rail 1a arranged on the upper chord 3 (see FIG. 2b). In case of a so-called underslung application, where the crane trolley is suspended from the girder 1, the running surface 7 is provided on a lower chord 4 of the girder 1 (see FIG. 2a). The lower chord 4 may also be designated as a bottom flange. For this purpose, in FIG. 2a the chord plate 2d forms the lower chord 4 and protrudes horizontally and laterally from the two side plates 2a, 2b in a transverse direction with respect to and along the longitudinal extension L of the girder 1. The running surface 7 is thus divided by the two side plates 2a, 2b. In view of FIGS. 2a and 2b it becomes evident that the girder 1 is configured so that each chord plate 2c, 2d can alternatively form the upper chord 3 in a first orientation of the box girder 1 or the lower chord 4 in a second orientation of the box girder 1. As a result, independently from the orientation of the box girder 1, the running surface 7 for wheels 6 of a crane trolley is provided on the same chord plate 2d. It is also indicated in FIGS. 2a and 2b that the thickness t2 of the chord plate 2d is greater than the thickness t1 of the chord plate 2c, owed to the fact that the chord plate 2d is providing the running surface 7 for both the top running crane trolley application and the underslung application.

[0044] The box girder 1 shown in FIG. 1a has a box-shaped cross-sectional shape in the above-defined sense that is determined by four sheet metal plates 2a, 2b, 2c, 2d welded together, so that a hollow space is enclosed. In the present case a quadrangular cross-sectional shape of the hollow space is obtained from the arrangement of the four plates 2a-2d that all have a flat shape. In particular the girder 1 comprises a first side plate 2a, a second side plate 2b, a first chord plate 2c and a second chord plate 2d. Both side plates 2a, 2b may also be designated as web plates. The side plates 2a, 2b are horizontally spaced apart from each other and form vertical side walls of the girder 1. The upper chord 3 is formed by the horizontally orientated first chord plate 2c and the lower chord 4 is formed by the horizontally orientated second chord plate 2d.

[0045] Both chord plates 2c, 2d are connecting the two side plates 2a, 2b to each other so that the hollow space is enclosed. Furthermore, a welded joint is provided between outer sides of the respective chord plate 2c, 2d and the side plates 2a, 2b, wherein each side plate 2a, 2b is connected to each chord plate 2c, 2d on the respective outer side and by means of a weld seam S1 of the fillet weld type (see also FIG. 2a and FIG. 2b), so that the plates 2a-2d are welded together in pairs. Thus, the girder 1 can also be designated as a welded beam.

[0046] It is also indicated in FIGS. 1a and 1b that an exemplary number of four transverse plates 5 are arranged between the side plates 2a, 2b connecting the side plates 2a, 2b to each other while each transverse plate 5 extends transversely and at rights angles to the longitudinal extension L of the girder 1. In the side view of FIG. 1b the first side plate 2a is hidden behind the shown second side plate 2b and the receiving apertures 2f and corresponding plug-in portions 5ab that can be seen in FIG. 1a are hidden by the chord plate 2c. The transverse plates 5 are spaced apart from each other at positions P1, P2, P3, P4 along the longitudinal extension L and serve as transverse bulkheads or diaphragms. In FIG. 1a a first outer transverse plate 5 and the inner transverse plates 5 are exemplified with dashed lines at positions P1, P2 and P3.

[0047] A form-fitting connection, in particular a plug-in connection, is provided between each transverse plate 5 and the side plates 2a, 2b, respectively. Further, a form-fitting connection, in particular a plug-in connection, is also provided between each transverse plate 5 and the first chord plate 2c. The form-fitting connections are produced during pre-assembly of the girder 1 and prior to welding the plates 2a, 2b, 2c and 5 together as described below. The positions P1, P2, P3, P4 of the transverse plate 5 with respect to the longitudinal extension L and seen from a first end E1 of the girder 1 are determined by respective receiving apertures 2e, 2f that serve as assembly slots (see also FIG. 1b). For this purpose, the receiving apertures 2e, 2f are designed as through-holes and are provided in the plates 2a, 2b, 2c along the longitudinal extension L. As a result, implementation of the corresponding form-fitting connection is possible by plugging a plug-in portion 5ab, 5ac of the transverse plate 5 into the respective receiving aperture 2e or 2f. All receiving apertures 2e, 2f that define one of the positions P1, P2, P3 or P4 for the corresponding transverse plate 5 are arranged within an imaginary plane at the respective position P1, P2, P3 or P4 with the plane extending transversely and at rights angles to the longitudinal extension L. In the present example there is one lateral receiving aperture 2e in each side plate 2a, 2b and one receiving aperture 2f in the first chord plate 2c at positions P1 and P4. At positions P2 and P3 there are three lateral receiving apertures 2e in each side plate 2a, 2b and also one receiving aperture 2f in the first chord plate 2c.

[0048] Of course, the number of receiving apertures 2e, 2f in each plate 2a, 2b, 2c and per position P1, P2, P3, P4 as well as the number of the corresponding plug-in portions 5ab, 5ac may vary. However, at least one lateral receiving aperture 2e in each side plate 2a, 2b and optionally at least one receiving aperture 2f in one of the chord plates 2c, 2d and corresponding plug-in portions 5ab, 5ac are preferred at each position P1, P2, P3, P4.

[0049] Furthermore, it is indicated in FIG. 1a and FIG. 1b that two different embodiments of the transverse plates 5 are used in the illustrated example. Starting from the first end E1 of the girder 1, the first outer transverse plate 5 according to a first embodiment is provided at the first position P1 close to the first end E1 with respect to the longitudinal extension L. Such a transverse plate 5 according to the first embodiment is exemplified in FIG. 1a with dashed lines and is also shown in FIG. 3a and described in detail below.

[0050] Further apart from the first end E1 and from the first transverse plate 5 two further transverse plates 5, each according to a second embodiment, are exemplified in FIG. 1a with dashed lines at positions P2 and P3, respectively. As can be seen in FIG. 1a, the transverse plates 5 according to the second embodiment have two opposing plug-in portions 5ab that are designed to form support elements 5b extending through the corresponding receiving apertures 2e of the opposite side plates 2a, 2b. The support elements 5b are configured so that a crane equipment element like a profile 1b in the form of a U-tube for receiving a power supply line for the above-mentioned drive-motors of the crane can be attached to the support element 5b outside the hollow space of the girder 1 and next to the corresponding side plate 2a or 2b as shown in FIG. 1a. Alternatively, the attachable crane equipment element may also be a platform for personnel. In the present example the support element 5b and corresponding receiving apertures 2e are those of the three plug-in portions 5ab and receiving apertures 2e that are situated closest to the chord plate 2d. However, as can be seen in FIGS. 1a and 2a, there is still enough space for the wheels 6 between the support elements 5b and the running surface 7 in case of the illustrated underslung application. A corresponding transverse plate 5 according to the second embodiment is also shown in FIG. 3b and described in detail below.

[0051] In the region of the second end E2 (see FIG. 1b) of the girder 1 which is opposing the first end E1 another transverse plate 5 according to the first embodiment is provided at position P4. Thus, the two outer transverse plates 5 that are arranged close to the ends E1, E2, respectively, are designed according to the first embodiment. The inner transverse plates 5 that are arranged between the aforementioned outer transverse plates 5 are designed according to the second embodiment.

[0052] Of course, the number of transverse plates 5 may vary and there may be more than two inner transverse plates 5 or only one inner transverse plate 5, depending on the desired length of the girder 1. Moreover, other arrangements and combinations of the two embodiments of transverse plates 5 are possible and it is also possible to use only identical transverse plates 5 according to the same embodiment, for example only transverse plates 5 that each have at least one support element 5b according to the second embodiment or only transverse plates 5 where no support elements 5b are formed. The latter may the case if no profile 1b or any other crane equipment element needs to be attached to the girder 1.

[0053] The receiving apertures 2e, 2f that are provided in the plates 2a, 2b, 2c for producing the respective form-fitting connection with the corresponding plug-in portion 5ab, 5ac of the transverse plates 5 have a substantially complementary shape relative to the cross-section of the respective plug-in portion 5ab, 5ac. As can be seen from FIG. 1a, 1b and especially from detail A in FIG. 1b, the lateral receiving apertures 2e may have a long hole shape with parallel longitudinal sides and corresponding edges and narrow sides which forms rounded ends and corresponding edges of the respective receiving aperture 2e. The same applies to the shape of the receiving apertures 2f of the chord plate 2c. The distance of the longitudinal sides of the receiving apertures 2e, 2f is slightly wider than the thickness of the transverse plates 5 and its plug-in portions 5ab, 5ac so that insertion of the plug-in portions 5ab, 5ac into and/or through the receiving apertures 2e, 2f is allowed. Furthermore, the longitudinal sides of the apertures 2e, 2f are in parallel with respect to the above-mentioned imaginary plane, in particular defining the corresponding imaginary plane at the respective positions P1, P2, P3, P4.

[0054] In connection with the above-mentioned features it is thus within the scope of the present invention to provide a pre-assembly method for manufacturing the above-described girder 1. A main aspect of the pre-assembly method is that at least one form-fitting connection, in particular plug-in connection, is produced between the respective transverse plate 5 and the two opposing side plates 2a, 2b, respectively, before the welded joint between the respective chord plate 2c, 2d and the side plates 2a, 2b is produced. In addition to this, at least one form-fitting connection, in particular plug-in connection, may also be produced between the transverse plate 5 and one of the chord plates 2c, 2d before the welded joint between the respective chord plate 2c, 2d and the side plates 2a, 2b is produced. In the present example only the first chord plate 2c is connected to the transverse plates 5 by means of such a form-fitting connection. In contrast, a form-fitting plug-in connection according to the invention is dispensed with between the second chord plate 2d and the transverse plates 5, in order to improve the fatigue strength and resistance of the plate 2d.

[0055] Producing the form-fitting connection(s), in particular plug-in connection(s), is enabled due to the specific and accurate provision of the plug-in portion(s) 5ab, 5ac on the transverse plate(s) 5 and the corresponding receiving aperture(s) 2e, 2f in the plates 2a, 2b, 2c. As a result of these structural features, producing of the form-fitting connection(s) between the plates 2a, 2b, 2c and 5 goes along with aligning them in their final positions for the completed girder 1. Thus, it is achieved that the final positions are maintained until the final welding process is completed only by means of the form-fitting connections so that an easy pre-assembly prior to the final welding process is possible. This applies to all modifications of the girder 1 according to the invention, regardless of the number of transverse plates 5, plug-in portions 5ab, 5ac and corresponding receiving apertures 2e, 2f.

[0056] Subsequent to producing the above-described form-fitting connection(s), a further force-transmitting connection is produced between the transverse plates 5 and the respective side plates 2a, 2b and/or between the transverse plates 5 and the respective chord plate 2c. In the present example the further force-fitting connection is a welded joint, in particular comprising weld seams S1 of the fillet weld type and weld seams S2 of the plug weld type. The positions of these weld seams S1, S2 are schematically illustrated in FIGS. 1a, 1b, 2a and 2b. It is also indicated in FIG. 1a, 2a and 2b that the regular plug-in portions 5ab, 5ac not forming support elements 5b do not protrude through the corresponding receiving apertures 2e, 2f, but only into the receiving aperture 2e, 2f. In FIGS. 2a and 2b the positions of the hidden regular plug-in portions 5ab, 5ac and the corresponding receiving apertures 2e, 2f are indicated. In these cases the plug-in portions 5ab, 5ac are welded to the corresponding plate 2a, 2b, 2c by means of weld seams S2 of the plug weld type. In contrast, the plug-in portions 5ab forming support elements 5b protrude through the corresponding receiving apertures 2e and beyond the outside of the respective plate and thus to the outside of the girder 1 and its hollow space. In these cases the plug-in portions 5ab, i.e. the support elements 5b, are welded to the corresponding plates 2a, 2b by means of weld seams S1 of the fillet weld type. All weld seams S1, S2 connect the corresponding plug-in portion 5ab, 5ac to an edge of the respective receiving aperture 2e, 2f. As indicated in FIG. 1b, there can be provided two weld seams S1 on the opposing sides of each support element 5b so that the support element 5b is welded to both opposing longitudinal sides/edges of the corresponding receiving aperture 2e.

[0057] FIG. 3a, 3b show plan views of the two embodiments of the transverse plate 5. The transverse plates 5 according to both embodiments are formed symmetrically in relation to their respective longitudinal axis LA. As a result, identically designed side plates 2a, 2b can be used so that the lateral receiving apertures 2e are mutually opposing at each position P1, P2, P3, P4 as it is indicated in FIGS. 2a and 2b. Furthermore, the transverse plates 5 according to both embodiments comprise an elongate shape in the direction of the longitudinal axis LA and have a rectangular and planar main surface 5e. The plug-in portions 5ab, Sac are each formed as a protrusion of an outer edge of the transverse plate 5 with respect to the main surface 5e. In other words, the outer edge is protruding from the rectangular shape of the main surface 5e in order to form the respective plug-in portion 5ab for the side plates 2a, 2b or the plug-in portion 5ac for the chord plate 2c. In the present embodiments all plug-in portions 5ab, 5ac have a rectangular shape, however other shapes are of course possible.

[0058] In order to form the plug-in portions 5ab for the side plates 2a, 2c and thus also the support elements 5b, the longitudinal edges of the transverse plates 5 extending in parallel to the longitudinal axis LA are offset away from the longitudinal axis LA in comparison with the remaining longitudinal edges defining the main surface 5e. Thus, the longitudinal edges of the plug-in portions 5ab have a greater distance from the longitudinal axis LA than the longitudinal edges of the main surface 5e outside the plug-in portions 5ab. The offset of the longitudinal edges of the plug-in portions 5ab with regard to the longitudinal edges of the main surface 5e is dimensioned so that the plug-in portions 5ab protrude through the lateral receiving apertures 2e only for those plug-in portions 5ab that are designed to form support elements 5b. Thus, the support elements 5b extend further transversely to the longitudinal axis LA than the regular plug-in portions 5ab. Accordingly, the offset of the remaining regular plug-in portions 5ab not forming support elements 5b is smaller so that the plug-in portions 5ab do not protrude beyond the outside of the side plates 2a, 2b. Thus, the maximum offset of the regular plug-in portions 5ab depends on the thickness of the side plates 2a, 2b. The same applies to the dimension of the offset of the regular plug-in portions 5ac for the chord plate 2c. In contrast to the plug-in portions 5ab, the plug-in portion 5ac is formed at the first end 5c of the transverse plates 5. For this purpose, the edge of the corresponding narrow side of the transverse plates 5 is offset away from the remaining edge defining the main surface 5e at the narrow side. The maximum offset of the plug-in portion 5ac depends on the thickness of the chord plate 2c.

[0059] It can also be seen from FIGS. 3a and 3b that the transverse plates 5 of both embodiments differ from each other in that the transverse plate 5 in FIG. 3a has only two opposing regular plug-in portions 5ab but no plug-in portion 5ab that is designed to form a support element 5b, whereas the transverse plate 5 in FIG. 3b has two opposing plug-in portions 5ab forming support elements 5b and two further pairs of opposing regular plug-in portions 5ab. Besides these differences, the height h, the width w1 and the width w2 of both embodiments are the same.