MOBILE CRANE COMPRISING A SUPERSTRUCTURE HAVING AT LEAST ONE BEARING POINT FOR PINNING ON A BOOM

Abstract

The disclosure relates to a mobile crane comprising a superstructure having at least one bearing point for pinning on a boom, wherein the bearing point comprises two spaced apart side parts that each have a bore for receiving the pin; and wherein the boom comprises at least one connection part that is provided with a bore and that can be introduced between the side parts such that a common connection pin can be pushed through the bores of the side parts and the connection part, wherein the clear width between the side parts is larger than the width of the connection part of the boom, and wherein a step pin is provided as a connection pin and its formed shoulder forms an abutment for the connection part of the pinned boom in the pinned position.

Claims

1. A mobile crane comprising a superstructure having at least one bearing point for pinning on a boom, wherein the at least one bearing point comprises two spaced apart side parts that each have a bore for receiving a pin; and wherein the boom comprises at least one connection part that is provided with a bore and that can be introduced between the two spaced apart side parts such that a common connection pin can be pushed through the bores of the two spaced apart side parts and the at least one connection part, wherein a clear width between the two spaced apart side parts is larger than a width of the at least one connection part of the boom; and in that a step pin is provided as a connection pin and its formed shoulder forms an abutment for the at least one connection part of the pinned boom in the pinned position.

2. The mobile crane in accordance with claim 1, wherein the formed shoulder of the step pin projects into a space between the two spaced apart side parts and the at least one connection part in the pinned position and limits play of the pinned boom in an axial direction of the step pin.

3. The mobile crane in accordance with claim 2, wherein the step pin is pushed or pushable in a direction toward a boom luffing axis.

4. The mobile crane in accordance with claim 1, wherein a pin diameter for forming the step is larger than a diameter of a bushing inserted into the bore of the at least one connection part; and in that the step forms an abutment for a front face of the bushing.

5. The mobile crane in accordance with claim 2, wherein a pin pulling device is provided for automatic pulling and pushing of the step pin.

6. The mobile crane in accordance with claim 5, wherein the pin pulling device comprises a hydraulic cylinder as an actuator whose cylinder is formed by a hollow space of the step pin, with a setting piston being fixed to the superstructure in a stationary manner and the step pin being linearly displaceable on the setting piston.

7. The mobile crane in accordance with claim 5, wherein one or more guide rods are provided along which the step pin is linearly displaceably guided.

8. The mobile crane in accordance with claim 7, wherein one or more latching pins are provided that extend transversely to the axial direction of the step pin and that limit an axial movement of the pin in the pulling direction.

9. The mobile crane in accordance with claim 8, wherein the one or more latching pins are directly supported at the superstructure to introduce axial forces acting on the pushed-in step pin directly into the superstructure.

10. The mobile crane in accordance with claim 8, wherein the one or more latching pins are releasably connected to the superstructure via at least one force baffle in a form fitting manner and to the step pin via relief plates.

11. The mobile crane in accordance with claim 5, wherein the pin pulling device is arranged outwardly at one of the two spaced apart side parts.

12. The mobile crane in accordance with claim 7, wherein one or more guide rods are installed at the superstructure.

13. The mobile crane in accordance with claim 12, wherein the one or more guide rods are installed at the two spaced apart side parts of the superstructure.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0018] Further properties of the disclosure will be explained in more detail in the following with reference to an embodiment shown in the Figures. There are shown:

[0019] FIGS. 1 to 3: different perspective sectional representations of the innovative pin connection between the boom and the superstructure with an inserted step pin;

[0020] FIG. 4: a perspective side view of the pin pulling device; and

[0021] FIG. 5: a perspective side view of a mobile crane whose boom is connected to the superstructure construction via the pin connection in accordance with the disclosure.

DETAILED DESCRIPTION

[0022] The installation and dismantling of a boom at the superstructure of a mobile crane should be simplified by the solution in accordance with the disclosure. FIG. 5 shows a detailed section of such a mobile crane comprising an undercarriage 2 having a chassis, with a superstructure 3 being placed thereon rotatable about a vertical axis. A main boom 4 is connected, for example, pinned, in an articulated manner to the superstructure luffable about a horizontal axis. Two pinning points 5 with connection pins 50 in accordance with the disclosure that are pushed in the direction of the luffing axis of the boom 4 from the outside are required for the pin connection,

[0023] Details of the pinning points 5 in accordance with the disclosure will be discussed in the following with reference to the detail views shown in FIGS. 1 to 4. The pinning point 5 between the boom 4 and the superstructure 3 is substantially formed by two parallel side walls 31a, 31b of the superstructure 3 that are spaced apart from one another by a clear width to provide space for introducing a connection part 4a of the boom 4. Both wide walls 31a, 31b and the connection part 4a of the boom 4 are equipped with bores 4b for receiving a connection pin 50. A boom bushing 7 is additionally introduced into the bore 4b of the connection part 4a.

[0024] To simplify the installation/dismantling of the boom 4, the width of the boom 4 that is defined via the outer spacing of the end faces of the boom bushing 7 is kept smaller than the clear width of the steel construction in the superstructure 3, i.e. between the side parts 31b on the left and right sides. The axial play of the connection part 4a and of the respective side wall 31b thus achieved on the left and right sides should respectively be in the range of 5 mm. This would be sufficient for a substantially faster installation and dismantling of the boom 4.

[0025] The connection pin 50 used is designed as a step pin 50 that has a shoulder 51 having a larger diameter as a substantial feature. The shoulder 51 projects slightly out of the bore 31c of the right side wall 31b into the clear space between the side walls 31a, 31b in the installed state (see FIG. 2). The shoulder 51 additionally also projects toward the outside on the oppositely disposed side of the side wall 31b in the pushed-in pin state. The part of the shoulder 51 projecting into the clear width between the side parts 31a, 31b forms an abutment for the front face of the boom bushing 7 so that the axial play of the boom is ultimately limited within the two side parts 31a, 31b. The geometrical design of the shoulder 51 is important here. It must be selected sufficiently large so that it can take up the axial force from the front face of the boom bushing 7. The surface pressure that has to be transferred in a harmless manner must be observed here.

[0026] The design is mirror inverted, but otherwise identical, for both pin points in accordance with FIG. 5. On the dismantling, the shoulder 51 together with the step pin 50 moves away from the boom bushing 7 and the available play increases. The boom 4 can be easily removed from the auxiliary crane. The installation is equally more simply possible due to the now existing axial play.

[0027] In the dimensioning of the step pin and also of the bearing points within the side walls 31a, 31b, the statistical notch in the pin 30 has to be observed that is present due to the diameter variation. The boom bushing 7 introduces a perpendicular force (radial to the bearing point) into the bearing region (side walls 31a, 31b) of the step pin 50. One of the two abutments of the step pin 50, the outer side wall 31b here, has a larger bore diameter for the pin leadthrough since the shoulder 51 of the step pin 50 has to be supported in this region. The cross-sectional change is thus located in the heavily loaded region of the step pin 50. The step pin 50 does not only have to be able to endure this load without damage and in the long term, but this capability must also be demonstrated by calculation with the necessary safety supplements.

[0028] An axial force, i.e. in the axial direction of the pin 50, can arise in crane operation in addition to the radial force. This force is mainly caused by starting or braking in slewing gear operation. The load here has to be laterally accelerated, whereby lateral forces arise in the pin connection 5 of the boom 4. This axial force predominantly has to be taken up by the shoulder 51 in the solution in accordance with the disclosure and the step pin 50 would forward the force to a pin pulling device 10 installed outwardly at the superstructure construction 3.

[0029] The pin pulling device 10 is hydraulically actuable, with the hollow step pin 50 forming the cylinder chamber 50a. A setting piston 57 is disposed within the chamber 50a and the latter is closed in a pressure-tight manner by means of the termination plate 58. The rod of the setting piston 57 is led through to the outside via a rod leadthrough of the termination plate 58.

[0030] The design of the inner hydraulic components of the pin pulling device 10 can, however, not be designed as so strong that it could take up the axial force to be borne by the shoulder 51 in crane operation. The pin pulling device 10 has to be protected from the axial force in crane operation for this reason. This is achieved by a latch device 101 (FIGS. 1 and 4). It includes the two force baffles 311, 312 that are fastened to the superstructure construction 3 above and below the displacement path of the step pin. Each of these force baffles 311, 312 provides two leadthroughs through which latching pins 313, 314 can be pushed, and indeed such that they extend in parallel with one another in the vertical direction. Relief plates 52, 53 that likewise have leadthroughs for receiving the latching pins 313, 314 are provided as mating connection elements at the connection plate 58 or directly at the step pin 50. If the latching pins 313, 314 are pushed through the leadthroughs into the force baffles 311, 312 or the relief plates 52, 53, the step pin 50 is fixed, as is shown in FIG. 4, for example. The axial forces acting on the step pin 50 are thus introduced directly into the superstructure construction 3 via the latching pins 313, 314 and the force baffles 313, 314 and the pin pulling device 10 is thereby effectively protected.

[0031] The upper end of the latching pins 313, 314 projecting over the upper force baffle 311 has an eyelet through which a securing pin 315 can be pushed. When not in use, i.e. when the step pin 50 is to be pulled, the securing pin 315 is removed and the latching pins 313, 314 can be pulled out upwardly out of the plates 311, 312, 52, 53. The latching pins 313, 314 can be stowed at the superstructure 3 by means of the holder 316.

[0032] Due to the step-like design of the step pin 50, its diameter additionally varies in the direction of displacement. The bore diameter of the outer side part 31b of the superstructure 3 is coordinated with the diameter of the shoulder 51. If the step pin 50 is pulled by the pin pulling device 10, the diameter-reduced part of the step pin 50 is located in the bore 31c of the side part 31b and a sufficient support is no longer ensured (see FIG. 3). The forces and torques caused by its own weight have to be taken up by additional guide means in this position. For this purpose, a total of four guide rods 102-105 are arranged around the bore of the side part 31b that extend outwardly in the displacement direction of the pin. The free ends of the guide rods 102-105 are connected to one another via an end plate 59. The oppositely disposed end of the guide rods 102-105 is connected to the side part. The termination plate 58 of the step pin 50 is guided by sliding surfaces along the respective guide rods 102-105.

[0033] The free end of the piston rod 57 is additionally installed at the end plate 59; a connection position for the hydraulic supply of the pin pulling device are equally accommodated there.

[0034] FIGS. 1-5 show example configurations with relative positioning of the various components. If shown directly contacting each other, or directly coupled, then such elements may be referred to as directly contacting or directly coupled, respectively, at least in one example. Similarly, elements shown contiguous or adjacent to one another may be contiguous or adjacent to each other, respectively, at least in one example. As an example, components laying in face-sharing contact with each other may be referred to as in face-sharing contact. As another example, elements positioned apart from each other with only a space there-between and no other components may be referred to as such, in at least one example. As yet another example, elements shown above/below one another, at opposite sides to one another, or to the left/right of one another may be referred to as such, relative to one another. Further, as shown in the figures, a topmost element or point of element may be referred to as a “top” of the component and a bottommost element or point of the element may be referred to as a “bottom” of the component, in at least one example. As used herein, top/bottom, upper/lower, above/below, may be relative to a vertical axis of the figures and used to describe positioning of elements of the figures relative to one another. As such, elements shown above other elements are positioned vertically above the other elements, in one example. As yet another example, shapes of the elements depicted within the figures may be referred to as having those shapes (e.g., such as being circular, straight, planar, curved, rounded, chamfered, angled, or the like). Further, elements shown intersecting one another may be referred to as intersecting elements or intersecting one another, in at least one example. Further still, an element shown within another element or shown outside of another element may be referred as such, in one example.

[0035] The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.