Tower crane

Abstract

The invention relates to a tower crane, preferably a rotary tower crane, particularly preferably a top-slewing crane, comprising a jib and a counter-jib. The jib and/or counter-jib is hinged to the tower top and/or rotating platform by means of at least one connection point. A first connection part of the at least one connection point has a concave stop surface, and a second connection part of the connection point comprises a convex counter-stop surface, wherein the counter-stop surface of the second connection part acts on the stop surface of the first connection part by means of a pressure force in order to produce a force-fitting connection between the connection parts.

Claims

1. A tower crane, having a boom and a counterboom, wherein at least one of the boom and counterboom is connected in an articulated manner to at least one of a tower tip and a slewing platform by at least one connection point, a first connection part of the at least one connection point has a concave abutment surface and a second connection part of the connection point comprises a convex counter-abutment surface, with the counter-abutment surface of the second connection part acting by compressive force on the abutment surface of the first connection part, the second connection part comprises a connection head having a defined radius as the counter-abutment surface, the first connection part is configured as a connection socket having an inner radius adapted to the radius of the connection head as the abutment surface, and said concave abutment surface and convex counter-abutment surface are configured to contact one another and fit and be secured together by movement of said second connection part only along a common axis orthogonal to a vertical direction, wherein said head of said second connection part extends from an end face thereof having said convex counter-abutment surface with a positive radius of curvature dimensioned smaller than a negative radius of curvature of said concave abutment surface of said first connection part.

2. A tower crane in accordance with claim 1, wherein the compressive force is produced by at least one boom guying and/or by a load torque.

3. A tower crane in accordance with claim 1, wherein at least one connection pin is insertable transversely to a longitudinal beam axis, for fixing the connection with corresponding pin slots provided both at the first and second connection parts.

4. A tower crane in accordance with claim 3, wherein said pin slot for the connection pin at the second connection part is formed by a bore at a center of the radius of the connection head.

5. A tower crane in accordance with claim 1, wherein the at least one connection point is arranged directly at the tower tip or at a slewing platform provided in the region of the tower tip.

6. A tower crane in accordance with claim 1, wherein the first connection part is a component of the tower tip or of the slewing platform and the second connection part is arranged at the boom or counterboom.

7. A tower crane in accordance with claim 1, wherein at least one capturing eye is provided above the abutment surface or counter-abutment surface at the second or first connection part in assembly position, through which capturing eye a capturing pin extends, with the capturing eye being dimensioned larger than periphery of the capturing pin.

8. A tower crane in accordance with claim 7, wherein the capturing eye is formed by an aperture within a metal sheet that is perpendicular on the connection head.

9. A tower crane in accordance with claim 1, wherein one or more capturing metal sheets are provided in the region of the convex abutment surface that assist the leading together of the convex counter-abutment surface and the concave abutment surface during boom assembly.

10. A method of assembling a boom or counterboom at a tower crane, comprising the following steps: providing the tower crane of claim 1; moving the boom or counterboom into the region of the tower tip and capturing the boom/counterboom by leading capturing means through a capturing eye; and adjusting the boom or counterboom to lead the abutment surface and counter-abutment surface together and inserting a pin through the second connection part.

11. A method in accordance with claim 10, wherein a boom guying is tensioned or load torque is produced by lowering the boom after the insertion of the pin to apply compressive force to the connection point.

12. A method of dismantling a boom or counterboom at a tower crane comprising the following steps: providing the tower crane of claim 1; drawing a pin inserted through the second connection part; aligning the boom/counterboom such that capturing means are freely suspended within a capturing eye; and pulling out the capturing means.

13. The crane of claim 1, wherein the compressive force is provided by guying said second connection part toward said first connection part.

14. A tower crane, having a boom and a counterboom, wherein at least one of the boom and counterboom is connected in an articulated manner to at least one of a tower tip and a slewing platform by at least one connection point, a first connection part of the at least one connection point has a concave abutment surface and a second connection part of the connection point comprises a convex counter-abutment surface, with the counter-abutment surface of the second connection part acting by compressive force on the abutment surface of the first connection part, the second connection part comprises a connection head having a defined radius as a counter-abutment surface, the first connection part is configured as a connection socket having an inner radius adapted to the radius of the connection head as the abutment surface, said first connection part additionally comprises side metal sheets on opposite sides thereof, and said side metal sheets each having a bore for receiving a pin therethrough, being substantially parallel with one another, projecting beyond an upper edge of said first connection part, and comprising edge regions angled outwardly to form a receiving funnel for the second connection part.

15. The crane of claim 14, wherein said second connection part comprises a bore therethrough and extending transversely to a longitudinal boom axis, such that the pin extends through said bores of said second connection part and side metal sheets to form a pivot axis between said first and second connection parts.

16. The crane of claim 14, wherein said second connection part comprises a sheet extending upwardly therefrom and comprising an aperture, and additionally comprising a capturing pin for extending through said aperture and a second set of bores through said side metal sheets to capture said second connection part therebetween.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages and properties of the invention will be explained in more detail in the following with reference to an embodiment shown in the drawings:

(2) There are shown:

(3) FIG. 1: perspective side views of a connection point in accordance with the invention between the boom or counterboom and the tower crane;

(4) FIG. 2: a sectional representation through the connection point in accordance with the invention;

(5) FIG. 3: perspective side views of the second connection part provided at the boom or counterboom;

(6) FIG. 4: perspective representations of the first connection part arranged at the tower tip or slewing platform;

(7) FIG. 5: a slightly modified embodiment of the connection point in accordance with the invention.

(8) FIG. 6: an overall view of a crane with an assembled boom/counterboom; and

(9) FIG. 7: a further view of a crane with an assembled boom/counterboom.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(10) An embodiment of the invention will be explained in more detail in the following. FIGS. 1 to 4 show different views of the innovative connection point of the crane in accordance with the invention, with FIGS. 1a, 1b showing perspective side views of the existing connection; FIG. 2 showing a sectional representation in a longitudinal direction through the existing connection; FIGS. 3a, 3b showing perspective side views of the second connection part; and FIGS. 4a, 4b show ng perspective representations of the first connection part. An individual connection point is shown in each case, but the total connection between the boom/counterboom and the crane tip takes place by a plurality of such connection points.

(11) The first connection point 10 is a component of the crane tip or of a slewing platform provided at the crane tip and is shown separately in FIGS. 4a, 4b. It is configured in the form of a connection socket 11 whose inner wall 12 has a concave shape with a negative radius of curvature. Side metal sheets 13a, 13b are attached, in particular screwed to the connection part 10, on both sides of the first connection part 10 in the region of the connection socket 11 and are initially in parallel with one another, but are angled outwardly in the boom direction forming an introduction funnel. The angled regions 14a, 14b form introduction aids for the introduction of the complementary connection part 20 into the connection socket 11. The side metal sheets 13a, 13b additionally project beyond the upper edge of the first connection part 10 and each have a bore 16 for receiving a pin at their upper end whose purpose will be explained later.

(12) The complementary second connection part 20, shown separately in FIGS. 3a, 3b, is formed by the connection head 21 that extends at the end face from the corresponding articulated connection region of the boom/counterboom in the direction of the crane tip. The connection head 21 comprises a convex counter-abutment surface 22 whose positive radius of curvature is dimensioned as slightly smaller than the radius of the abutment surface 12.

(13) Once the connection head 22 has been introduced into the connection socket 12, both connection parts 10, 20 can be pivoted with respect to one another about a horizontal axis due to the mutually matched radii, which is in particular of advantage during the assembly procedure. The connection section is substantially force fit since the second connection part 20 or the boom/counterboom is drawn in the direction of the tower tip or into the connection socket 12 by a guying. Oppositely directed tensile forces are removed by the connection pin 35 that is inserted through corresponding bores 15 of the side metal sheets 13a, 13b and through a central bore 25 of the connection head 22 transversely to the longitudinal boom axis. The connection pin 35 thus also forms the pivot axis of the two connection parts 10, 20. There is a force ratio here of approximately 10:1 between compressive forces and tensile forces during crane operation so that the connection pin 35 can be dimensioned as considerably smaller due to the comparatively small tensile forces.

(14) It is still noteworthy that the width of the connection socket 12 should be larger than the width of the connection head 22.

(15) A metal sheet 30 extends perpendicularly upwardly on the upwardly disposed peripheral surface of the connection head 22 and has a large-dimensioned circular aperture 31. This aperture serves as a capturing eye 31 that inter alia serves the capture of the boom/counterboom during the crane assembly. If the boom/counterboom taken up by an auxiliary crane is brought into proximity with the crane tip at the start, a capturing pin 36 can be inserted as a capturing means through the capturing eye 31 and through the bores 16 of the side metal sheets 13a, 13b. The boom part/counterboom part thereby captured can thereby be aligned more simply in the final position with respect to the establishing of the connection, i.e. the connection head 22 is introduced into the connection socket with the assistance of the introduction aids 14a, 14b. Finally, the connection pin 35 is inserted and the boom guying is tensioned or the top flange lug is connected.

(16) The diameter of the capturing pin 36 is dimensioned as considerably smaller than the diameter of the capturing eye 31, which considerably simplifies the capturing of the second connection part. The capturing eye, however, also takes over a securing function during the dismantling process to avoid an uncontrolled pivoting away of the boom or counterboom. The boom or counterboom is taken up by the auxiliary crane and the connection pin 35 is drawn during the dismantling process. A comparatively small movement of the boom or counterboom is hereby produced if it had not been exactly received at its center of gravity by the auxiliary crane. This pivot movement is, however, bounded by the still inserted capturing pin 36 that abuts the inner wall of the capturing eye 31. In the following step, the crane operator of the auxiliary crane has to align the boom or counterboom so much that the capturing pin 36 is suspended within the capturing eye, i.e. does not abut the inner margin. If this is the case, the taken up boom part/counterboom part is in equilibrium and an unwanted pivot movement can be precluded after the drawing of the capturing pin 36. The boom or counterboom can then be let down by the auxiliary crane without risk.

(17) A slightly modified embodiment of the connection point in accordance with the invention can be seen from FIG. 5. This embodiment differs with respect to the features key to the invention in the embodiment of the connection part 20. The connection head 21′ and the capturing eye 31′ are formed in one piece here. The capturing eye 31′ also does not have a circular aperture, but rather has an oval or rectangular aperture having rounded corners.

(18) FIGS. 6, 7 respectively show an overall view of a tower crane whose boom 20 is assembled in the region 1 by means of the connection point in accordance with the invention at the crane tip or a slewing platform provided there. The force fit connection closure is achieved in the crane of FIG. 7 since the second connection part 20 (boom/counterboom) is drawn in the direction of the tower tip or into the connection socket 12 by the guying 2. In the crane type of FIG. 6, this force is generated by the load torque of the boom/counterboom.