Tower crane

Abstract

The invention relates to a tower crane with a crane tower and a jib mounted thereon as well as a counter-jib, wherein the length of the counter-jib is defined by the number of the counterweights received.

Claims

1. A tower crane comprising: a crane tower and a jib mounted thereon; and a counter-jib, wherein a length of the counter-jib is defined by a number of counterweights; wherein a first counterweight is mounted to a free end of a steel structure of the counter-jib, and any other counterweights are directly connected to the first counterweight or to one another; wherein at least one counterweight of the number of couterweights comprises at least one cantilevered panel to retain the at least one counterweight at a respective bearing point of the steel structure of the counter-jib or a further counterweight; wherein the at least one counterweight additionally comprises at least one tab or at least one rigid hook establishing a tensile connection with the steel structure or the further counterweight; and wherein at least one attachment rod extending transversely to a jib direction is provided at the steel structure or the further counterweight as a counter-element for the at least one tab or at least one rigid hook.

2. The tower crane according to claim 1, wherein at least two counterweights of the number of counterweights in a counter-jib direction are mounted successively.

3. The tower crane according to claim 1, wherein the bearing point of at least one counterweight is formed by a recess of an upper side of the counterweight.

4. The tower crane according to claim 3, wherein a continuous platform is formed when successively arranging multiple counterweights through the recess.

5. The tower crane according to claim 4, wherein the counterweights are identical.

6. The tower crane according to claim 4, wherein at least one of the counterweights is surrounded at least partially by a steel frame.

7. The tower crane of claim 4, wherein at least one part of the counterweights differ in at least one of thickness, perimeter, shape, or type of material used.

8. The tower crane of claim 3, wherein the recess extends in the jib direction continuously through the counterweight.

9. A counterweight for ballasting a counter-jib of a tower crane, wherein the counterweight comprises at least one cantilevered panel to retain the counterweight on a horizontal bearing point, as well as at least one tab or at least one rigid hook, for establishing a tensile connection with an attachment rod; wherein the counterweight comprises a bearing point for retaining the cantilevered panel of a further counterweight, wherein the bearing point is formed by a recess on an upper side of the counterweight and the recess extends in a mounting position in a jib direction continuously on the upper side through the counterweight; wherein the counterweight is provided with a frame enclosing a ballast element; and wherein the frame provides support to the ballast element.

10. The counterweight according to claim 9, wherein the frame enclosure is made of steel.

11. The counterweight according to claim 9, wherein the counterweight does not have a cleat.

12. The counterweight of claim 9, wherein the cantilevered panel is in the form of at least one cleat.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1: a rear view of the counterweight of the invention;

(2) FIG. 2: a detailed view of the counter-jib of the tower crane according the invention in a side view with mounted counterweights, and

(3) FIG. 3: an alternative embodiment of the counterweights according to the invention.

DETAILED DESCRIPTION

(4) The idea according to the invention of the present application is that the counterweights are designed self-supporting for the maximum possible counterweight ballasting for compensating the torques of the tower crane.

(5) In doing so, only the innermost counterweight 10 is connected to the rear end of the steel structure of the counter-jib 100. Any further counterweights 11 are connected to one another without being required to connect them directly to the steel structure of the counter-jib 100. This has the advantage that the steel structure of the counter-jib 100 may be designed really short which is particularly advantageous for the transportation of the tower crane.

(6) Moreover, the length of the counter-jib 100 may be optimally adjusted to the equipped jib length of the jib 120 of the tower crane 1 with a crane tower 110 using the number of ballasted counterweights 10, 11. For example, short jib lengths get a short counter-jib due to the small number of necessary counterweights 10, 11 which is advantageous for the non-operational state, particularly regarding the function rotating in the wind, as well as in the event of cramped construction site conditions. In contrast, long jib lengths get a long counter-jib length due to the large number of required counterweights which is advantageous for the economic dimensioning of the rotary mechanisms.

(7) FIG. 1 shows the counterweight 10, 11 according to the invention in a rear view. In this perpendicular installation position, it is mounted to the steel structure or a front counterweight from the back. In the example embodiment, the first 10 and any further counterweights 11 are identically designed according to FIG. 1. The counterweights 10, 11 provide for a hexagonal basic shape. Within the context of the invention, the counterweights may of course have every other basic shape. For mounting on the steel structure or a front counterweight 10, 11, two cleats 30 as well as two pull tabs 20 are available as attachment means (see FIG. 2). The two cleats 30 cantilever into the shown perpendicular position of the elements 10, 11, preferably in the upper third of the front side parallel to one another on the left and right side. Similarly, two pull tabs 20 extend parallel to each other, each perpendicular to the ground surface, to the front, wherein one pull tab 20 is mounted each on the right and left side near the top edge. Furthermore, the pull tabs 20 are pivotably hinged to the counterweight 10, 11.

(8) In FIG. 2, it is also apparent that the first counterweight 10 is put from above onto the steel structure of the counter-jib 100 using the cleat 30 and accordingly secured using the pull tab 20. In doing so, the cleats 30 are put onto a horizontal bearing surface of the steel structure and the tabs 20 are hooked on a suitable attachment rod 101 of the counter-jib 100.

(9) Any further counterweight 11 is also put from above onto the respective front counterweight 10, 11 using their cleats 30 as well as the pull tabs 20. As a result, a plurality of counterweights 10, 11 is stacked successively in counter-jib direction such that the entire jib length of the counter-jib 100 is defined by the number of the counterweights 10, 11.

(10) For receiving the cleats 30 of the rear counterweight 11, each counterweight 10, 11 also comprises an appropriate bearing point to be able to put the cleats 30 from above onto the horizontal bearing surface. These bearing surface is formed by a continuous recess 13 of the upper side 12, as depicted in FIG. 1, for example. The recess is continuous in the longitudinal direction which results in the upper side 12 forming a rectangular channel which extends in the longitudinal direction of the jib whose horizontal bottom surface serves as the bearing point for receiving the cleats 30. In the illustration of FIG. 1, the cleats of the counterweight 11 located behind are marked with the reference number 30. At the top edge of the recess 13, an attachment rod 21 extends transversely to the jib direction. At this attachment rod 21, the pull tabs 20 of the adjacent counterweight 11 may be hooked into.

(11) A particular advantage of this arrangement is that the steel structure of the counter-jib 100 has no given fixed points for the various counterweights 11. This allows an optimal counterbalancing of the weight balance of the counter-jib 100 with various weights 10, 11. For example, it may be conceivable that the counterweights 10, 11 have various basic shapes on the one side, but particularly differ regarding various widths, i.e. the thickness in jib direction. This allows a particularly flexible configuration of the counterweight. It is furthermore conceivable that especially the rearmost counterweight 11 is designed particularly long to intentionally increase the resulting wind attack surface of the counter-jib 100.

(12) Furthermore, the counterweights 10, 11 may also be employed across multiple crane types as the fixed point to the steel structure 100 may be standardized. The multiple application is advantageous for the flexible usage within rental pools and creates economies of scale during manufacturing.

(13) When the counterweights are connected to one another using the tensile connection and cleat bearing, a lateral platform is no longer necessary as it is formed by the recesses 13 of the counterweights 10, 11 extending in line. This hidden arrangement of the platforms within the counterweights 10, 11 may lead to a smaller wind surface and thus to reduced costs for the counter-jib 100. Furthermore, a respective and distinctive product design may be implemented. The attachment rods 21 may be used as a railing for the platform at the same time.

(14) Alternatively to the pivotable pull tab 20 according to FIG. 2, a stationary horizontal safety hook 23 according to FIG. 3 may be employed as well.

(15) Additionally, the counterweights 10, 11 may be designed with a supporting steel frame 14 which passes around the perimeter of the counterweight 10, 11. Only the upper side 12 is recessed. Thus, the steel frame 14 not only has a supporting function, but also serves for the protection against transport and mounting damages. Furthermore, the steel frame may serve as a permanent shuttering already during manufacturing of the counterweights 10, 11. The additional costs incurred for the more complex ballast elements 10, 11 may be compensated with an advantageous construction by savings at the counter-jib 100, particularly due to the elimination of the platforms and the support structure for the counterweights.