Telescopic jib bracing device

Abstract

A telescopic jib bracing unit for a mobile crane includes a holding frame which is embodied for fastening to the telescopic jib of the mobile crane and exhibits an open cross-section, the cross-sectional opening of which enables the jib to be retracted into the holding frame, and two bracing supports which are connected by the holding frame to form a structural unit. Two frame parts which form the open cross-section of the holding frame are coupled to each other via a coupling point such that they can be moved with respect to each other. A bracing unit transport system, a mobile crane and a fitting method are also provided.

Claims

1. A telescopic jib bracing unit for a mobile crane, comprising: a holding frame configured for fastening to the telescopic jib of the mobile crane and having an open cross-section configured to enable the jib to be inserted into the holding frame; and two bracing supports connected by the holding frame to form a structural unit, wherein two frame parts forming the open cross-section of the holding frame are coupled to each other via a coupling point such that they are movable with respect to each other.

2. The bracing unit according to claim 1, wherein the two frame parts are coupled to each other such that moving the frame parts with respect to each other alters an opening width of the open cross-section.

3. The bracing unit according to claim 1, wherein the two frame parts are coupled to each other such that moving the frame parts with respect to each other alters a design breadth of the bracing unit.

4. The bracing unit according to claim 1, wherein the two frame parts are coupled to each other rotationally via the coupling point by a rotational joint, a rotational axis of which extends specifically parallel to a longitudinal axis of the jib.

5. The bracing unit according to claim 1, wherein the two frame parts are coupled to each other translationally via the coupling point by a guide.

6. The bracing unit according to claim 1, wherein movement of the two frame parts is assisted and generated by an actuator having at least one hydraulic cylinder.

7. The bracing unit according to claim 1, wherein the holding frame is configured such that the opening in the open cross-section widens autonomously in a suspended state and/or in a resting position deposited on a crane undercarriage.

8. The bracing unit according to claim 1, wherein the holding frame is configured such that the two frame parts autonomously abut the jib as the jib is inserted into the holding frame.

9. The bracing unit according to claim 1, wherein the holding frame has a cross-section which opens upwards and enables the bracing unit to be fitted by luffing the jib off and/or out.

10. The bracing unit according to claim 1, wherein the bracing unit is configured to be deposited on an undercarriage of the mobile crane for the purpose of fitting using the mobile crane itself.

11. The bracing unit according to claim 1, wherein the bracing unit is provided with defined abutments via which it can be deposited on an undercarriage of the mobile crane and/or on a transport vehicle.

12. The bracing unit according to claim 1, wherein the bracing unit is configured to remain deposited on an undercarriage of the mobile crane and/or bolted to the jib of the mobile crane during transport.

13. A bracing unit transport system, comprising: the bracing unit according to claim 1; and a transport vehicle configured for transporting the bracing unit, wherein the bracing unit and/or the transport vehicle is/are configured such that a design breadth of the bracing unit deposited on the transport vehicle is reduced autonomously.

14. A telescopic crane comprising: an undercarriage and a superstructure rotatably arranged on the undercarriage and on which a luffing jib is arranged which comprises an outer base part of the jib and one or more telescopic parts of the jib; and the bracing unit according to claim 1.

15. A method for fitting a telescopic jib bracing unit on a mobile crane, comprising the steps of: providing the bracing unit according to claim 1 which can be transported separately from the mobile crane; depositing the bracing unit on an undercarriage of the mobile crane using the mobile crane itself; positioning the bracing unit on the jib by a luffing movement of the jib; and bolting the bracing unit to the jib.

Description

(1) The invention is described below in more detail on the basis of an embodiment and by means of the enclosed drawings. It can comprise any of the features described herein, individually and in any expedient combination. The drawings show:

(2) FIG. 1 a bracing device deposited on a transport vehicle;

(3) FIG. 2 a bracing device suspended on the load hook of a crane;

(4) FIG. 3 a crane comprising a bracing device deposited on its undercarriage;

(5) FIG. 4 the bracing device in a widened resting position on the crane undercarriage;

(6) FIG. 5 a jib which is inserted into the holding frame;

(7) FIG. 6 a bracing device which is bolted to the jib;

(8) FIG. 7 a first embodiment of the bracing device, in a transport arrangement;

(9) FIG. 8 the bracing device from FIG. 7, in a widened resting position;

(10) FIG. 9 the bracing device from FIG. 7, in a normal position corresponding to the jib profile;

(11) FIG. 10 a second embodiment of the bracing device, in a transport arrangement;

(12) FIG. 11 the bracing device from FIG. 10, in a widened resting position;

(13) FIG. 12 the bracing device from FIG. 10, in a normal position corresponding to the jib profile.

(14) FIG. 1 shows a bracing unit 9 in accordance with the present invention, being transported on a low loader 8, separately from the remainder of the mobile crane, wherein the bracing unit 9 assumes a position on the low loader 8 in which it exhibits a smaller design breadth than in an arrangement in which it is deposited on the crane undercarriage 1 or even bolted on the jib 3, wherein FIG. 7 illustrates how the smaller design breadth of the bracing unit 9 can be achieved, namely by turning the two frame parts 101 and 102 about the rotational joint 19, such that the latter assumes a lower position relative to the frame parts 101 and 102 than in a normal arrangement.

(15) FIG. 2 shows a perspective view of the bracing unit 9 in accordance with the invention, which substantially consists of two symmetrically arranged bracing supports 11 and the corresponding holding frame 10, wherein the holding frame 10 is sub-divided into two frame parts 101 and 102 which can be rotated relative to each other about the central rotational joint 19. In the state of the bracing unit 9 shown in FIG. 2, it is suspended on a crane hook 30 by means of the sling 21, wherein the sling and/or cables 21 attach in the region of the rotational joint 19 and the abutment supports 17, such that the bracing device 9 widens autonomously due to its inherent weight, i.e. the frame parts 101 and 102 are rotated about the rotational joint 19 such that the latter comes to rest in a higher position relative to the frame parts 101 and 102 than in a normal arrangement of the holding frame 10, wherein the bracing supports 11 themselves are embodied in a way which is already known. Specifically, they each comprise a winch 16 for bracing the jib and are erected by means of the erecting cylinders 12 in the jib luffing plane and also secured again after use, while they can be moved out of and also back into the jib luffing plane by means of the respective pivot brackets 13 and pivot cylinders 14. The bracing supports 11 can thus assume a so-called V arrangement or Y arrangement, wherein the jib bracing can then also absorb lateral loads, such as wind loads, on the crane jib 3.

(16) FIG. 3 shows the next step in fitting the bracing device 9 in accordance with the invention, in which the latter is deposited in the front region of the crane undercarriage 1. It demonstrates that the bracing unit 9 can be independently positioned on the crane undercarriage 1 by the mobile crane, such that separate lifting gear does not have to be provided.

(17) FIG. 4 shows the bracing unit 9 fully positioned on the crane undercarriage 1, wherein it should be noted that the abutments 17 and 18 of the bracing unit 9 come to rest in defined regions of the crane undercarriage 1, in order to be able to bolt the bracing unit 9 to the jib 3 as soon as the latter has been inserted into the holding frame 10 and/or the frame parts 101 and 102 of the holding frame 10. In the embodiment shown, the holding frame 10 is bolted to the collar 6 of the base body 4. For this purpose, the jib 3 has to be lowered (luffed off and/or out) into a substantially horizontal position, such that the collar 6 is inserted into the holding frame 10 and comes to rest in the holding frame 10. An essential aspect of the present invention can likewise be gathered from FIG. 4: as can be gathered from the foregoing FIGS. 1 to 3, the bracing supports 11 of the bracing device 9, which is separated from the remainder of the mobile crane, are aligned parallel to each other. When the holding frame 10 is rigid, with an invariable profile and an open cross-section, the space provided between the bracing supports 11 is thus directly dependent on the distance between the upper ends of the U-shaped holding frame 10. If more space is needed for inserting the jib 3 into and extending it out of the holding frame 10 again, this has hitherto been possible only by increasing the design breadth of the holding frame 10. When being transported on a low loader 8 separately from the mobile crane, however, the holding frame 10—as also the entire bracing device 9 itself—must not exceed a given maximum breadth. In large mobile cranes which exhibit correspondingly large jib cross-sections, as equally with cranes comprising twin luffing cylinders which extend beyond the lateral breadth of the jib 3, it has for this reason been hitherto near-impossible to implement a bracing unit 9 which can be fitted on the jib 3 “from below”. As can be gathered from FIG. 4, widening the holding frame 10 and thus also the entire bracing unit 9 additionally enables the luffing cylinders, which are arranged on both sides of the jib 3, to be guided past the bracing supports 11 without any problems.

(18) As soon as the luffing cylinders have been guided past the bracing supports 11, and the jib 3 and/or the collar 6 of the outermost telescope section 4 has been submerged into the holding frame 10, the bracing supports 11 can be guided back to the jib 3 by abutting the frame parts 101 and 102 against the jib 3 and/or the collar 6. In the example shown, this is achieved by the collar 6 running onto the rotational joint 19, which lies centrally below it, and pressing the latter downwards, wherein the abutments 18 which are provided on both sides of the holding frame 10 and support it roll off on the crane undercarriage 1 and thus enable the respective frame parts 101 and 102, which lie on the crane undercarriage 1, to rotate. The same applies to the abutments 17 below the bracing supports 11, wherein in the example shown, the abutments 18 on the crane undercarriage 1 fulfil the additional function of guiding the holding frame 10 on the crane undercarriage 1 as it is placed onto the jib 3. For this purpose, a rail-like guiding structure 20 (FIGS. 4 to 6) is provided on the undercarriage 1, which enables the abutments 18 to roll off but prevents them from moving in the longitudinal direction of the crane. This can for example be achieved by one or more grooves and/or rails transverse to the longitudinal direction of the crane, in which the abutments 18 are held by the inherent weight of the bracing device 9, even when they are rolling off on the crane undercarriage 1. If the frame parts 101 and 102 can be shifted translationally with respect to each other, the guiding structure 20 can be adapted to the translational (rather than rotational) movement, in order to fulfil the same function.

(19) In general terms, the guiding structure 20 can enable the frame parts 101 and 102 and/or their abutments 18 to move during fitting but prevent them from moving in the longitudinal direction of the crane. Such a guiding structure can also be provided for the rearward abutments 17. Since, in the embodiment shown, the latter lie on the crane undercarriage 1 at substantially the same point when rolling off, the guiding structure at said location can take the form of an indentation or recess on the crane undercarriage 1 which prevents the respective abutments 17 from moving translationally in any horizontal direction. If such a translational movement—such as a movement in the transverse direction of the crane—is desirable, the guiding structure for the rear abutments 17 can of course likewise comprise rails or grooves such as have already been described for the front guiding structure 20.

(20) FIG. 6 shows the holding frame 10 of the bracing unit 9 in accordance with the invention, in a state in which it is placed onto the jib 3 and in which the holding frame 10 can be bolted to the collar 6 of the outermost telescope section 4 by activating the locking cylinders 15.

(21) The cross-sections of the different arrangements of the frame parts 101 and 102 with respect to each other shown in FIGS. 7 to 9 illustrate again the advantages of the present invention: FIG. 9 shows a normal arrangement of the frame parts 101 and 102 relative to each other, in which the holding frame 10 abuts and can be bolted to the collar 6 and/or the outer circumference of the jib 3. In this arrangement, it is not possible to insert the jib 3 into the holding frame 10 and/or extend it out of the holding frame 10 again, since the available opening width D6 is not sufficient for this purpose. It is also possible for the design breadth D3 shown in FIG. 9 to exceed a permitted maximum value for road transport.

(22) The present invention remedies both problems by pivoting the frame parts 101 and 102 with respect to each other via the central rotational joint 19. On the one hand, this enables the opening width of the holding frame 10, which is relevant to inserting and extending again, to be widened to a larger distance D5, wherein the design breadth D2—which is likewise increased relative to the design breadth D3 of the normal arrangement—is irrelevant, since this arrangement is not assumed until the mobile crane is fitted at the site of operation. For road transport, the frame parts 101 and 102 of the embodiment shown are pivoted in opposite directions with respect to each other, such that the design breadth D1 of the bracing device 9 assumes a value which is permitted for road transport and smaller than the design breadth D3 of the normal arrangement. The opening width D4, which is reduced relative to the normal arrangement, is again irrelevant in the transport state.

(23) FIGS. 10 to 12 show an embodiment of the bracing device 9 in accordance with the invention in which the frame parts 101 and 102 are moved translationally with respect to each other, rather than rotationally as in the embodiment shown in FIGS. 7 to 9. This translational movement in the horizontal direction is generated by an actuator 21 which in FIG. 12 is shown schematically as a hydraulic cylinder but can equally comprise a rack-and-pinion drive or similar means suitable for translational movement. While FIG. 10 shows a transport arrangement which exhibits reduced breadths D1 and D4 (corresponding to the rotational arrangement shown in FIG. 7), FIG. 11 shows a fitting arrangement which exhibits extended breadths D2 and D5 (corresponding to the rotational arrangement shown in FIG. 8), and FIG. 12 shows an operating arrangement of the frame parts 101 and 102 (corresponding to the rotational arrangement shown in FIG. 9), wherein in the latter arrangement, the frame parts 101 and 102 can be bolted to the crane jib 3.