LIFTING SYSTEM AND LIFTING METHOD FOR A CRANE

Abstract

A lifting system for a crane for generating a hoist rope pretension during a travel of a suspension element of the crane is provided. The system includes a separable pretension hook block and a connected auxiliary rope that is supported in a windable and unwindable manner on an auxiliary winch on the crane, and that is guided over a deflection apparatus arranged or installable at a boom of the crane. The pretension hook block comprises two lockable hook block parts that are releasably lockable to one another, that are connected to one another via the auxiliary rope, and of which an upper hook block part has a fastening means for fastening to the suspension element of the crane and a lower hook block part has a pick-up means for fastening a weight.

Claims

1. A lifting system for a crane for generating a hoist rope pretension during a travel of a suspension element of the crane, the lifting system comprising: a separable pretension hook block; and an auxiliary rope that is connected to the hook block, the auxiliary rope supported in a windable and unwindable manner on an auxiliary winch arranged or installable on the crane, and that is guided via a deflection apparatus that is arranged or installable at a boom of the crane, wherein the pretension hook block comprises two hook block parts that are releasably lockable to one another, that are connected to one another via the auxiliary rope, and of which an upper hook block part has a fastening means for fastening to the suspension element and a lower hook block part has a pick-up means for fastening a weight.

2. The lifting system in accordance with claim 1, wherein the upper hook block part comprises at least one first deflection pulley and the lower hook block part comprises at least one second deflection pulley via which the auxiliary rope is guided.

3. The lifting system in accordance with claim 1, wherein the pretension hook block has at least one deflection pulley to lead the auxiliary rope laterally past the suspension element.

4. The lifting system in accordance with claim 1, wherein the pretension hook block comprises a guide mechanism by means of which the lower and upper hook block parts are configured to be brought into a defined locked position on bringing together.

5. The lifting system in accordance with claim 1, wherein the lower and upper hook block parts have connections means for the releasable locking to one another.

6. The lifting system in accordance with claim 1, wherein the lower and upper hook block parts are lockable by an actuable locking mechanism.

7. The lifting system in accordance with claim 6, wherein the locking mechanism is adapted to lock automatically on bringing together of the lower and upper hook block parts.

8. The lifting system of claim 1, further comprising: a hoist winch on which a hoist rope connected to the suspension element is supported in a windable and unwindable manner.

9. The lifting system in accordance with claim 8, further comprising: a crane control that is configured to control the hoist winch and the auxiliary winch synchronized such that a weight fastened to the unlocked pretension hook block that is unlocked is held suspended at a certain height or in a certain region above the ground during a travel of the suspension element by reeling up the hoist winch and simultaneously unreeling the auxiliary winch.

10. A crane, having a lifting system in accordance with claim 1.

11. A pretension hook block of a lifting system in accordance with claim 1 and having an auxiliary rope fastening means for fastening the auxiliary rope.

12. A method of lifting a suspension element of a crane using a lifting system in accordance with claim 1, the method comprising: fastening the pretension hook block to the suspension element that is lowered; unlocking the upper and lower hook block parts; fastening a weight to the lower hook block part; lifting the suspension element, whereby the lower and upper hook block parts move away from one another; and placing the weight down by unreeling the auxiliary winch while the suspension element is in its raised position and releasing the lower hook block part from the weight.

13. The method in accordance with claim 12, wherein the lower hook block part is raised by reeling up the auxiliary winch and is brought together with the upper hook block part after placing down and releasing of the weight so that the hook block parts can be locked to one another.

14. The method in accordance with claim 12, wherein the hoist winch and the auxiliary winch are controlled synchronously or synchronized for the travel of the suspension element.

15. The method in accordance with claim 14, wherein travel of the suspension element takes place in a two-hook operation monitored by the crane control.

16. A method for use of a lifting system in accordance with claim 1, comprising the steps: fastening the pretension hook block to the suspension element that is lowered; unlocking the upper and lower hook block parts; fastening a weight to the lower hook block part; lifting the suspension element, whereby the lower and upper hook block parts move away from one another; and simultaneous unreeling the auxiliary winch such that the weight remains on the ground and a constant strand tension is present in an auxiliary winch rope.

17. The lifting system in accordance with claim 4, wherein the guide mechanism includes one or more of (a) at least one guide rail or (b) a tongue-in-groove mechanism.

18. The lifting system in accordance with claim 5, wherein the lower and upper hook block parts are configured to be pinned by one or more pins.

19. The lifting system in accordance with claim 6, wherein the locking mechanism is actively or passively actuable on or after bringing together of the hook block parts.

20. The lifting system in accordance with claim 7, wherein the locking mechanism includes one or more of a spring element or a snap-in-mechanism.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Further features, details, and advantages of the invention result from the embodiments explained in the following with reference to the Figures. There are shown:

[0050] FIG. 1: a schematic side view of the pretension hook block in accordance with the invention in a locked state suspended at a lifting hook of a crane in accordance with an embodiment;

[0051] FIG. 2: the pretension hook block in accordance with FIG. 1 in the unlocked state and having a weight taken up;

[0052] FIG. 3: a longitudinal section through the pretension hook block in accordance with the invention;

[0053] FIG. 4: a schematic side view of the boom tip of a crane with a suspension element, a mast nose, and a pretension hook block;

[0054] FIG. 5: a side view and a front view of the pretension hook block in accordance with the invention;

[0055] FIG. 6: a schematic representation of the connection regions of the upper and lower hook block parts of the pretension hook block in accordance with the invention in accordance with an embodiment;

[0056] FIG. 7: a side view of the superstructure of the crane in accordance with an embodiment with an indicated location of the hoist winch; and

[0057] FIGS. 8 to 11: different positions of the suspension element and the pretension hook block during the carrying out of the lifting method in accordance with the invention in accordance with an embodiment, in a side total view of the crane in each case.

DETAILED DESCRIPTION

[0058] FIG. 1 shows a schematic side view of the pretension hook block 10 of the lifting system in accordance with the invention in accordance with a preferred embodiment. The pretension hook block 10 is suspended at a suspension element 6 of a crane 1, with it here being a crawler crane 1 in the embodiments shown here.

[0059] The crane 1, that is shown in a total side view in FIGS. 8 to 11, comprises an undercarriage 8 having a crawler unit, a superstructure 3 supported on the undercarriage 8 rotatably about a vertical axis, a boom 2 connected in an articulated manner to the superstructure 3 pivotably about a horizontal axis, and a suspension element 6 for lifting loads that is designed as a roller frame 6a having a lifting hook 6b in the embodiments shown here.

[0060] The superstructure 3 of the crane 1 is shown isolated in a side view in FIG. 7. A hoist winch 5 on which a hoist rope 4 is windably and unwindably supported is located on the superstructure 3. The hoist rope 4 is connected to the suspension element 6 so that the suspension element 6 can be raised and lowered by actuating the hoist winch 5 or by reeling and unreeling the hoist rope 4.

[0061] The crane 1 furthermore has a hoist winch 14 on which a hoist rope 12 is windably and unwindably supported. As can be seen in FIG. 8, the auxiliary winch 14 is located in the lower region of the boom 2.

[0062] As is indicated in FIG. 4, the hoist rope 4 is guided at the boom tip to the hoist winch 6 over a deflection pulley of a roller head. A deflection apparatus 16 that is configured as a mast nose and has a deflection pulley over which the auxiliary rope 12 is guided is installed at the boom tip.

[0063] Reference is made in the following to FIGS. 1 to 3 that show the pretension hook block 10 in accordance with the invention in a locked state (FIG. 1) and in an unlocked state (FIGS. 1 to 2). FIG. 5 additionally shows side and front views of the pretension hook block.

[0064] The pretension hook block 10 in accordance with the invention is designed in two parts and comprises an upper hook block part 20 (upper block) and a lower hook block part 22 (lower block). A fastening means 21 via which the pretension hook block 10 can be lashed or fastened to the lifting hook 6b of the crane 1 is located at the upper side of the upper hook block part 20. A pick-up means 23 in the form of a further lifting hook to which a load or a weight 40 can be fastened is located at the lower side of the hook block part 22.

[0065] The two hook block parts 20, 22 can be locked to one another so that the pretension hook block 10 can be moved or raised as a whole (see FIG. 1). The locking can take place by means of one or more pins 30. As can in particular be recognized in FIG. 3, the upper hook block part 20 has a first deflection pulley 24 while the lower hook block part 22 comprises a second deflection pulley 26. The auxiliary rope 12 guided over the mast nose 16 is guided or reeved, starting from the mast nose 16, over the second deflection pulley 26 of the lower hook block part 22 and subsequently over the first deflection pulley 24 of the upper hook block part 20 and is connected to the lower hook block part 22 via a fastening means 29. The upper hook block part 20 furthermore has a further deflection pulley 28 to lead the auxiliary rope 12 laterally past the suspension element 6. The two hook block parts 20, 22 are connected to one another via the auxiliary rope 12 such that the spacing of the two hook block parts 20, 22 from one another is variable by a suitable control of the auxiliary winch 14.

[0066] A sufficiently great pretension on the lifting of the suspension element can be generated on the hoist rope 4 by means of the pretension hook block 10 in accordance with the invention in combination with the auxiliary winch 14, the auxiliary rope 12, and the mast nose 16 so that said hoist rope 4 is tautly wound onto the hoist winch 5. The occurrence of tangles is thereby prevented and a good winding quality is ensured.

[0067] If the suspension element 6 is to be raised by the crane 1 without an attached load for the purpose of a dismantling of a higher component, a weight 40 is fastened to the pick-up means 23 of the lower hook block part 22 of the pretension hook block 10 fastened to the suspension element 6, as is shown in FIG. 2. The weight 40 is connected via the pretension hook block 10 to the suspension element 6 and thus to the hoist rope 4 and generates a suitable pretension force.

[0068] The pulley block of the pretension hook block 10 implemented via the deflection pulleys 24, 26 and the fastening means 29 has the effect that the weight force of the weight 40 fastened to the pick-up means 23 is spread over the different strands of the hoist rope 12. Since the reeving of the auxiliary rope 12 of the pretension hook block 10 is selected with three reevings, with the first strand leading to the mast nose 16, two strands contribute to the increase of the pretension, i.e. approximately ⅔ of the ballast weight is suspended at the suspension element 6 and tension the hoist rope 4 that is reeled onto the hoist winch 5. More than three reevings of the hoist rope 12 or more than one respective deflection pulley 24, 26 can naturally be provided at the hook block parts 20, 22 here.

[0069] The two deflection pulleys 24, 26 have parallel axes of rotation. The fastening means 29 is located above the second deflection pulley 26 at the lower hook block part 22 while the pick-up means 23 is arranged beneath the second deflection pulley 26. The further deflection pulley 28 is located obliquely above the first deflection pulley 24 at the upper hook block part 20 while the fastening means 21 is arranged above the first deflection pulley 24.

[0070] As can be seen in FIG. 4, the spacing between the first deflection pulley 24 and the further deflection pulley 28 can substantially correspond to the spacing between the corresponding deflection pulleys for the hoist rope 4 and the auxiliary rope 12 at the boom head or at the mast nose 16.

[0071] As can be seen in FIG. 5, the two hook block parts 20, 22 can be pushed into one another, with the upper hook block part 20 having a pick-up region 34 configured as a tongue into a pick-up region of the lower hook block part 22 configured as a groove 32. The pick-up regions 32, 34 can be chamfered, whereby the threading or pushing in is facilitated.

[0072] As described above, the two hook block parts 20, 22 can be manually lockable via pins 30 (see also FIG. 5). An alternative embodiment is shown in sketched form in FIG. 6 in which the pretension hook block 10 has a locking mechanism. A retaining pin 38 is accordingly arranged in the upper region of the lower hook block part 22 while a pivotable hook element 36 is located at the lower region of the upper hook block part 20. On the brining together of the two hook block parts 20, 22, the pin 38 automatically pushes the hook 36 to the side and pivots it about its pivot axis, as shown. Once the hook block parts 20, 22 have reached their completely retracted licking position, the hook 36 snaps in and automatically locks the two hook block parts 20, 22. A spring element, not shown in any more detail, can be provided for this purpose that forces the hook 36 into its locked position. The hook block parts 20, 22 thereby do not have to be manually locked, which in particular facilitates the bringing together at great heights.

[0073] FIGS. 8 to 11 show an overall side view of the crane 1 during a travel of the suspension element 6 in accordance with an embodiment of the method in accordance with the invention. A start is made in this respect from the situation that a load is to be taken up from an elevated position and is to be placed on the ground 9 for dismantling. To be able to lift the suspension element 6 to the height of the load to be taken up with sufficient pretension, the previously lowered suspension element 6 is connected in a first step via the pretension hook block 10 to a weight 40. The pretension hook block 10 is suspended at the lifting hook 6b in the locked state. The weight 40 is fastened to the reception means 23 of the pretension hook block 10. During the suspending at the lifting hook 6b, the pretension hook block 10 can either already be connected to the auxiliary rope 12 or, for example during the first travel, the auxiliary rope 12 Is reeved into the pretension hook block 10 after the suspension thereof.

[0074] The pretension hook block 10 is now unlocked or unpinned and the weight 40 is raised slightly by actuation of the hoist winch 5 and the auxiliary winch 14 (see FIG. 8). The weight 40 can be raised from the ground here. The weight 40 can be held closely above the ground 9, in particular suspended, during the raising of the suspension element 6 by reeling up the hoist winch 6 and simultaneously unreeling the auxiliary winch 14, preferably by a corresponding control and monitoring of the crane control. As long as the weight 40 is in the suspended state, a high pretension is applied to the hoist rope 4 or to the hoist winch 5 due to its weight.

[0075] Once the suspension element 6 has been pulled up completely, i.e. up to the desired height, via the hoist rope 4 by means of the hoist winch 5 (see FIG. 9). the auxiliary winch 14 is unreeled, the lower hook block part 10 is let down, and the weight 40 is placed on the ground 9 and unhooked.

[0076] The lower hook part 22 is subsequently pulled up by reeling up the auxiliary winch 14 and is guided to the upper hook block part 20. Once the hook block parts 20, 22 are in their locked position, they can be pinned together (or an automatic locking takes place as explained above). This can take place from the elevated position where the load to be conveyed or to be placed down also has to be taken up. FIG. 10 shows the situation after the bringing together and locking of the hook block parts 20, 22 while the pretension hook block 22 of the pretension hook block 10 is still suspended at the suspension element 6.

[0077] The pretension hook block 10 can now be unhooked from the suspension element 6 of the crane 1 (see FIG. 11) and can subsequently be lowered to the ground 9 by means of the auxiliary winch 14. The suspension element 6 is still in the elevated position and can now be connected to the load to be conveyed. The load can be placed on the ground 9 by actuating the hoist winch 5. The above-explained steps can be carried out again for the next travel of the suspension element 6.

[0078] The weight 40 that is raised from the ground 9 and that has the result that the total pretensioning process can be monitored by the control of the crane 1 is advantageous in this method. The pretensioning process corresponds to regular crane operation. It is in this case a monitored two-hook operation having a hook 6b as the main travel at the main or hoist winch 5 and having a hook 23 at the auxiliary winch 14 via the mast nose 16 having a common load.

[0079] In this solution, no conversion work is necessary at the crane 1 that would require a separate static observation. Furthermore, no auxiliary vehicle has to be used for the application of the pretension. The auxiliary winch 14 for the auxiliary travel and the short mast nose 16 form part of the standard equipment with many lattice mast cranes and also with large telescopic cranes. The crane 1 can additionally be rotated and/or traveled during the pretensioning process, which is not possible with a solution having an auxiliary vehicle and/or an auxiliary winch placed on the ground.

REFERENCE NUMERAL LIST

[0080] 1 crane [0081] 2 boom [0082] 3 superstructure [0083] 4 hoist rope [0084] 5 hoist winch [0085] 6 suspension element [0086] 6a pulley block [0087] 6b lifting hook [0088] 8 undercarriage [0089] 9 ground [0090] 10 pretension hook block [0091] 12 auxiliary rope [0092] 14 auxiliary winch [0093] 16 deflection apparatus (mast nose) [0094] 20 upper hook block part [0095] 21 fastening means [0096] 22 lower hook block part [0097] 23 pick-up means (lifting hook) [0098] 24 first deflection pulley [0099] 26 second deflection pulley [0100] 28 deflection pulley [0101] 29 auxiliary fastening means [0102] 30 pin [0103] 32 groove [0104] 34 tongue [0105] 36 hook [0106] 38 pin [0107] 40 weight