Support for a crane

Abstract

The present disclosure relates to a support for a crane, in particular for a mobile crane, having at least two first support beams and two second support beams that are each arranged pairwise at mutually oppositely disposed sides of the support.

Claims

1. A support for a crane, comprising: at least two first support beams and two second support beams that are each arranged pairwise at mutually oppositely disposed sides of a vehicle frame, wherein a maximum deployment range of the first support beams is smaller than a maximum deployment range of the second support beams; wherein the first support beams are n-fold telescopic support beams and the second support beams are at least (n+1) fold telescopic support beams, wherein n=1; wherein the first support beams comprise single sliding beams and the second support beams comprise double sliding beams; and wherein the single sliding beams extend further than the double sliding beams.

2. The support in accordance with claim 1, wherein the crane is a mobile crane.

3. The support in accordance with claim 1, wherein the first support beams are arranged in a plane transverse to a longitudinal direction of the support or offset from one another.

4. The support in accordance with claim 1, wherein the second support beams are arranged in a plane transverse to a longitudinal direction of the support or offset from one another.

5. The support in accordance with claim 1, wherein the second support beams are arranged in a rear region or in a front region of the support.

6. The support in accordance with claim 1, wherein a tilt edge defined by the second support beams is arranged closer to a center of rotation of a superstructure of the crane than a tilt edge defined by the first support beams.

7. The support in accordance with claim 1, wherein the support is configured as an undercarriage or as part of an undercarriage of the crane or is composed of the undercarriage of the crane.

8. A crane, having a support, the support comprising at least two first support beams and two second support beams that are each arranged pairwise at mutually oppositely disposed sides of a vehicle frame, wherein a maximum deployment range of the first support beams is smaller than a maximum deployment range of the second support beams, wherein the support is configured as an undercarriage or as part of an undercarriage of the crane or is composed of the undercarriage of the crane; wherein the first support beams are n-fold telescopic support beams and the second support beams are at least (n+1) fold telescopic support beams, wherein n=1; wherein the first support beams comprise single sliding beams and the second support beams comprise double sliding beams; and wherein the single sliding beams extend further than the double sliding beams.

9. The crane in accordance with claim 8, wherein the crane is a mobile crane.

10. The crane in accordance with claim 8, wherein a tilt edge defined by the second support beams is arranged closer to a center of rotation of a superstructure of the crane than a tilt edge defined by the first support beams.

11. The support in accordance with claim 1, wherein either the first support beams or the second support beams are in a sliding beam box.

12. The support in accordance with claim 11, wherein at least one of the first support beams or the second support beams is detachable from the sliding beam box.

Description

BRIEF DESCRIPTION OF THE FIGURE

(1) FIG. 1 shows a schematic plan view of a support for a crane, in particular for a mobile crane, having a total of four support beams 1, 1, 2, 2 that are each arranged pairwise at mutually oppositely disposed sides.

DETAILED DESCRIPTION

(2) The two first mutually oppositely disposed support beams 1, 1 here have a smaller maximum deployment range than the two second mutually oppositely disposed support beams 2, 2. The maximum deployment range can here be defined as the maximum horizontal extent of the support beams 1, 1, 2, 2 perpendicular to the longitudinal axis of the support and away from the support. This extent is at a maximum when the support beams 1, 1, 2, 2 have been telescoped or pivoted outwardly. The longitudinal axis of the support is recognizable as the longest, transversely extending chain-dotted line.

(3) The dashed and dotted lines show the extent of a parallelogram-shaped support base from the prior art (dashed) and of a trapezoidal or at least approximately trapezoidal support base in accordance with the present disclosure (dotted).

(4) Lateral tilt edges of the support bases are shown at the top and bottom in FIG. 1 and front or rear tilt edges of the support bases that are associated with the respective support beams are shown at the left and right in FIG. 1. The spacing designated by the reference symbol a relates to the shortest spacing from a lateral tilt edge in the trapezoidal support base present in accordance with the present disclosure. The spacing designated by the reference symbol b corresponds to the shortest spacing from a lateral tilt edge in a parallelogram-shaped support base known from the prior art. Said spacings can be spacings between a center of rotation 3 of a superstructure of the crane and said tilt edges.

(5) Reference symbols L1 and L2 designate spacings from the center of rotation 3 of the superstructure from the front tilt edge or from the rear tilt edge. As can be seen from FIG. 1, the spacing a is only minimally smaller than the spacing b and only a minimal loss of support width thereby occurs in accordance with the present disclosure.

(6) The slewing platform contact point has the following properties: It is present as a construction feature and is fixed before a steel construction takes place, that is in the design phase. The position of the slewing platform on the undercarriage in the later configuration of the crane is fixed by it and it represents the center of rotation 3 of the superstructure in the product configuration or defines it.

(7) The meaning of an optimized ratio of the tilt edges is as follows: On the evaluation of the stability of the crane, the tilt load utilization of the crane can be taken into account. All the masses of the crane are furthermore taken into account. The mass or the mass distribution is known via reliably estimated weights of the assemblies. The support width belongs to two support beams arranged pairwise and having support cylinders. It is the spacing of the support cylinders in the transverse direction toward the vehicle frame. Two tilt edges meet in the support cylinders. The slewing platform contact point has a spacing from every tilt edge. A balancing calculation of the stabilizing moments and of the tilt moments takes place to optimize the ratios of the tilt edges.

(8) The advantage of the present disclosure comes into effect against this background. For although the support base (that is the size of the standing square) is reduced by the presence of only one support beam at one end of the crane, the stability only decreases by a negligible amount due to the design of the support in accordance with the present disclosure. The stabilities thus still remain balanced or coordinated with one another.

(9) The above-mentioned spacing, that is the spacing of the slewing platform contact point from the tilt edges, can be varied, for example, by shortening the support beams, equally by displacing the slewing platform contact point.

(10) Support bases can furthermore be imagined in which the support width at the side of the single sliding beams or of the first support beams 1, 1 is substantially less than at the side of the double sliding beams or of the second support beams 2, 2 or support bases in which the contact point is displaced more toward the single sliding beams 1, F.

(11) Furthermore, in conjunction with payloads dependent on the angle of rotation, in particular in the 360 range of rotation of the superstructure, or in conjunction with maximum permitted payloads for the respective angular position of the superstructure, the loss of stability can be compensated in that the superstructure is rotated in the direction of the supports.

(12) For the payload calculation takes place with payloads dependent on the angle of rotation with respect to the running time of the crane and takes account of the instantaneous spacing from the tilt edge and not the minimum of the range of rotation of 360. This can compensate the disadvantage in stability, but requires a more exact planning of the use, in particular of the positioning, of the vehicle or crane.

(13) To approximately reach the support widths of the double sliding beams or to keep the difference in support widths as small as possible, the single sliding beam solution means that the one sliding beam has to be slid out further than the two beams with the double sliding beam solution or that the clamping regionthat is the part of the sliding beams that is in the sliding beam boxis considerably smaller with single sliding beams than with double sliding beams.

(14) The loads or support forces in the clamping region of the support beams can thus increase considerably with the same undercarriage load capacity and the support region of both the single sliding beams and of the sliding beam box must be dimensioned greater than with double sliding beams of the same load capacity. Furthermore, the single sliding beam cannot be adapted as well to the load progression as is possible with double sliding beams (height, width, sheet metal thicknesses).

(15) Despite the aforesaid unfavorable constraints, it is nevertheless possible to configure the combination of sliding beam box/single sliding beams as lighter and also more favorable with the same undercarriage load capacity, which makes up a further advantage of the present disclosure.

(16) The first support beams 1, 1 arranged pairwise can be arranged at the rear or at the front at the undercarriage. The spacing L2 (spacing of the center of rotation 3 of the superstructure from the tilt edge of the second support beams 2, 2) is much smaller than the spacing L1 (spacing of the center of rotation 3 of the superstructure from the tilt edge of the first support beams 1, 1).

(17) Due to this arrangement, the shortest spacing a from the lateral tilt edge is only negligibly smaller with a trapezoidal support base than the shortest spacing b from the lateral tilt edge with a parallelogram-shaped support base having four sliding beams that can be telescoped twice. Only a minimal loss of the relevant support width and thus of the stability toward the lateral tilt edge is thus achieved with respect to the parallelogram-shaped support base.

(18) The present disclosure can comprise a combination of support beams arranged in pairs, being able to be telescoped twice, with support beams arranged in pairs and being able to be telescoped once. A support base can thereby be produced with maximally extended supports or support beams that is reminiscent of a trapezoid or that is a trapezoid.

(19) This so-called trapezoidal support base is furthermore characterized in that the front and/or rear supports or support beams are in a plane transverse to the longitudinal direction of the support or can also be arranged offset from one another. The latter is shown in FIG. 1.