GB2607149A - Locking system and locking method for ballast elements and mobile crane - Google Patents

Abstract

A system for releasably locking two ballast elements 10, 12 of a mobile crane, the first ballast element having a first cut-out 100 fastenable to a counterweight device 6 of the mobile crane and a second ballast element connectable to the first ballast element and having a second cut-out 120 that covers the first cut-out in the connected state. A locking device 20 for releasably connecting and locking the ballast elements has an elongate carrier 200 pushable through the first and second cut-outs and a locking element 202 that cooperates with a counter-locking element of the first and/or second ballast elements in a locked position. A support element 204 is spaced apart from the locking element and a securing mechanism (206 fig.3) fixes the locking device in the locked position. When the ballast elements are aligned the locking element can be pushed into place, rotated through ninety degrees , pulled up using handle 208 and a foldable bolt 210 may be inserted through aperture 201 to secure the lock in place.

Description

Liebherr-Werk Ehingen GmbH DE-89584 Ehingen Locking system and locking method for ballast elements and mobile crane The present invention relates to a system for releasably connecting and locking two ballast elements of a mobile crane.

Mobile cranes typically have an undercarriage having a chassis and a superstructure rotatably supported on the undercarriage and having a boom and a counterweight arrangement.. In the case of a wheeled chassis, the undercarriage is here drivable on a plurality of axles with wheels in public road traffic. Specifications relating to the loads that the axles may apply to the public road that differ from country to country apply in public road traffic. In this context, it represents an economic advantage to utilize the axial loads in the best possible manner and to have great variability with sufficiently small piece distribution stages of the counterweight.

The counterweight arrangement typically comprises a base counterweight plate, ballast elements that can be placed or stacked thereon, and a device to attach the base counterweight plate having the ballast elements to the superstructure. As a rule, thus device comprises hydraulic cylinders called ballasting cylinders that move or raise the base counterweight plate having the ballast elements to the superstructure. -2 -

To vary the axle loads when traveling in public road traffic, it is known from the prior art to not also remove one or more ballast elements for transport and to transport them separately, but rather to instead fixedly connect them to the steel construction of the superstructure. When the counterweight is removed, these ballast elements do not therefore move back to the undercarriage from where the components are then themselves removed from the mobile crane and placed on a separate transport vehicle. The nationally permitted axle loads can thereby be better utilized in that no, one, two, or more ballast elements selectively remain on the superstructure for the public road trip.

The ballast elements remaining on the superstructure are connected to the frame of a counterweight device of the superstructure via special connection means. Screws and/or bolt systems can be used as the connection means. If two or more ballast elements should remain on the superstructure for the travel in public road traffic, further connection means then have to be attached between the counterweights that connect the ballast elements to one another.

The ballast elements frequently have additional structures such as bollards at the outer sides for tying on a pulling means or connection means for hooking up further hook-in ballast elements. A use of laterally attachable connection systems for the ballast elements remaining on the superstructure is thereby avoided.

It is therefore the object of the present invention to provide a possibility with mobile cranes of the initially named kind to connect ballast elements remaining on the superstructure to one another in a simple, fast, and safe manner for road transport. The connection should in particular be able to take place without tools.

This object is achieved in accordance with the invention by a device having the features of claim 1. Advantageous embodiments of the invention result from the dependent claims and from the following description. -3 -

A system for releasably connecting two ballast elements of a mobile crane is accordingly proposed that comprises the following: a first ballast element having at least one continuous first cutout that is fastenable to a counterweight device of the mobile crane, with the counterweight device preferably being located at a superstructure of the mobile crane; a second ballast element reversibly connectable to the first ballast element and having at least one second cutout that covers the at least one first cutout of the first ballast element in the connected state; and at least one locking device for releasably connecting and locking the two ballast elements to one another.

The locking device in accordance with the invention here comprises: an elongate carrier pushable through the first and second cutouts; a locking element that is arranged at the carrier and that is configured to cooperate with a counter-locking element of the first and/or second ballast elements in a locked position for locking the two ballast elements; a support element that is arranged at the carrier, that is spaced apart from the locking element, and that is configured to take up forces acting on the first and/or second ballast elements in the locked position transverse to the longitudinal axis of the carrier; and a securing mechanism by means of which the locking device is fixable in the locked position.

The locking device in accordance with the invention provides a simple and fast possibility of connecting and locking the ballast elements to one another for the disposition at the counterweight device. It can in particular be moved without tools from a release position in which it can be introduced into the mutually covering cutouts into a locked position in which the ballast elements are locked to one another for road transport. If a taking along of both ballast elements is not necessary due to the situation, the second ballast element can be simply removed from the superstructure and transported separately, while the first ballast element is -4 -fastenable to the counterweight device, for example by means of screws and/or bolt connections.

The forces that occur on braking or accelerating or when cornering during the road travel can additionally be taken up directly by the provision of an additional support element at the carrier of the locking device and can be introduced into the mobile crane or into the counterweight device. The support element is an element differing from the locking element or the carrier. It can therefore be especially configured for an effective force absorption.

The ballast elements are in particular formed in plate shape. They are preferably arranged among one another in the connected or locked state, with the second ballast elements being located below the first ballast element fastened to the counterweight device. The locking device is therefore in particular vertically aligned in the locked position (assuming a planar, horizontal base) and is introduced into the ballast elements or their cutouts in a vertical direction. The arrangement of the locking device in the vertical direction is more space saving and flexible here than connection systems attachable or introducible at the side.

The carrier is preferably substantially rod-shaped or cylindrical, with the locking and support elements in particular projecting laterally from the carrier.

Provision is made in a possible embodiment that the support element is configured to cooperate with a counter-support element formed in the first cutout in the locked position of the locking device and to introduce forces acting transversely to the longitudinal axis of the carrier into the first ballast element. Since the first ballast element is directly connected to the counterweight device, forces that act on the first ballast element and that occur, for example, on an acceleration during the road travel are directly introduced into the counterweight device via the connection means. The forces acting on the second ballast element, in contrast, are conducted via the locking device into the first ballast element and/or into the counterweight device. The support element is provided and correspondingly configured for this purpose. -5 -

The counter-support element is preferably a wall of a support recess that is formed in the first cutout and in which the support element is located in the locked position. If a force acting in a transverse direction, i.e. perpendicular to the longitudinal carrier axis, that is in particular vertical, on the second ballast element exceeds a certain value that can be determined by the sticking friction between a support surface of the locking device and the second ballast element, the second ballast element moves relative to the first ballast element and presses against the locking element or the carrier. The support element is thereby pressed against the wall of the support recess in the first ballast element so that the force is introduced into the latter.

Provision is made in a further possible embodiment that the support element has at least one contact surface that is disposed opposite a wall, in particular a side wall, of the first cutout, in particular of a support recess formed in the first cutout, in the locked position and is configured to contact this wall on the occurrence of a force acting transversely to the longitudinal axis of the carrier in the first and/or second ballast elements and to introduce the force into the first ballast element. The contact in particular takes place as a result of a relative movement or of a slipping of the second ballast element relative to the first.

The support recess can be formed by a widened portion of the first cutout, i.e. a region having a larger diameter. It can have a circular or a non-circular contour (in a plan view) so that the support element can move within the support recess without jolting from the release position into the locked position on the movement of the locking device.

Provision is made in a further possible embodiment that the carrier, locking element, and support element are fixedly connected to one another, i.e. thy are not movably supported relative to one another. They are preferably formed in one piece, with the locking element and/or the support element also being able to be alternatively fastened to the carrier, for example by means of screws. Since the locking device is only one single part, a particularly simple handling results. No parts can be lost. -6 -

Provision is made in a further possible embodiment that the counter-locking element is provided in a locking recess that is formed in the second cutout and has an opening having a non-circular cross-section and that the locking element projects beyond the outer contour of the carrier in a plan view and likewise does not have any circular cross-section. The locking element is pushable through the opening, i.e. it passes through it, in a release position, while it does not pass through the opening in the locked position. The locking element is preferably configured to form a form fit with a wall of the locking recess in the locked position.

The locking recess into which the non-circular opening merges can likewise be non-circular. It only has to be ensured that sufficient space is present that the locking element can move from the release position into the locked position. This can take place in the locking recess itself or in a further recess adjoining the locking recess.

The locking recess can be configured as a groove that is in particular open toward the bottom and that has a shape complementary to the contour of the locking element so that it fits exactly into the groove in the locked position. The locking element can no longer rotate about the longitudinal axis of the carrier within the groove since it strikes against the walls in so doing. The locking recess can alternatively be formed as completely or at least sectionally circular so that only a pulling out of the locking element through the opening is blocked by the locking recess itself, but not a rotation about the longitudinal carrier axis. In this case, a different element or a different abutment can serve to block the rotation.

Provision is made in a further possible embodiment that the locking element has a shape or outer contour rectangular or triangular in a plan view, with the opening having a complementary rectangular or triangular contour through which the locking element is pushable in the release position, while it blocks a pulling out of the locking element in the locked position. Other geometries of the outer contours are alternatively also conceivable. The support element preferably has an outer contour that corresponds to the locking element in a plan view. -7 -

Provision is made in a further possible embodiment that the first and/or second cutouts does/do not have a circular cross-section sectionally. At least one of these sections is in particular the previously described opening of the locking recess.

Provision is made in a further possible embodiment that the locking element is arranged at one end of the carrier, the securing mechanism at the oppositely disposed end of the carrier, and the support element between the securing mechanism and the locking element. The phrase "at the end of the carrier" is to be given a broad interpretation here so that the respective element does not have to be located right at the end, but can also be arranged only in the region of the end.

Provision is made in a further possible embodiment that a handle is arranged at the end of the carrier disposed opposite the locking element for raising and/or moving the locking device from the release position into the locked position and vice versa, said handle preferably being pivotably supported at the carrier.

A recess into which the handle or the total upper section of the latching element is fully or partially lowerable can furthermore be provided in the region of the orifice of the first cutout. This recess is in particular dimensioned so generously that the actuation of the securing mechanism can take place within this recess.

Due to the pivotability, the handle does not project too far beyond the surface of the first ballast element in the locked state. The handle can also serve the tying of a pulling means. Provision can be made, for example, that the two ballast elements are connectable and lockable by means of the at least one locking device in a placed down state and that the connected ballast elements can then be raised via the locking device(s) to the superstructure or to the counterweight device and can be fastened there.

Provision is made in a further possible embodiment that the locking element has a support surface that is oriented transversely to the longitudinal axis of the carrier and -8 -on which the second ballast element lies in the locked position. The ballast elements are arranged above one another in the connected state and the second ballast element hangs via the at least one locking device at the first ballast element fastened to the superstructure. The locking device and the second ballast element are preferably configured such that the total weight force of the second ballast element is taken up from the at least one locking device and is introduced into the first ballast element and/or into the counterweight device of the mobile crane. The support surface can be formed at the locking element.

Provision is made in a further possible embodiment that the securing mechanism comprises a securing element that is in particular of bolt shape, that is pushable into a securing cutout extending transversely to the longitudinal axis of the carrier in the locked position, and is releasably lockable by a securing element locking means in a securing position. The locking device is fixable in the locked position by the securing mechanism and can no longer independently move into the release position. The securing element locking means can be a folding securing plug. The securing element can comprise a lever or a handle that facilitates the operation, in particular the plugging into or the pulling out of the securing cutout.

The securing element and/or the securing element locking means is/are preferably inseparably connected to the carrier. Inseparably here does not mean unmovably, but rather only that the parts always remain connected to the carrier and thus cannot be lost and thus cannot represent a risk for the environment. No loose parts are present. This additionally facilitates the operation of the locking device.

Provision is made in a further possible embodiment that the locking device comprises an abutment element that is displaceably supported at the carrier relatively thereto and has an abutment surface contacting the first ballast element in the locked position, with the carrier preferably being displaceably supported in a central cutout of the abutment element. The abutment element can surround the carrier as a sleeve and can be flattened toward the bottom (i.e. toward the surface of the first ballast element). The locking device is preferably pushed into the first cutout for so long until -9 -the abutment surface contacts the first ballast element. The locking device can then be moved into the locked position and the securing mechanism can be actuated.

Provision is made in a further possible embodiment that the abutment means has a transverse cutout that extends transversely to the longitudinal axis of the carrier through the central cutout and is movable into a covering with the securing cutout, through which the securing element is pushable, in the locked position. The abutment element and the carrier are therefore locked with one another in the securing position and they can no longer be moved with respect to one another.

A plurality of transverse cutouts or transverse bores that are spaced apart from one another (along the longitudinal axis) can be provided at the carrier to receive the securing element, with the individual transverse cutouts being bringable into coverage with the one transverse cutout of the abutment element at different positions of the locking device decisive for the locking process.

In a further possible embodiment, a locking abutment is provided that is configured to block an independent release of the locked position. The locking abutment preferably cooperates with the locking element in the locked position and is implemented by a lateral wall of a locking recess formed in the second cutout in which locking recess the locking element is located in the locked position and in particular has an inner contour complementary to the outer contour of the locking element. It is advantageous in this connection if the locking recess is configured as a groove that is open toward the bottom (with the counterweight device being located "at the top"), wherein the locking element moves into the groove after a rotation and subsequent raising of the locking device and is secured against rotation therein.

Alternatively, the locking abutment can be arranged outside the locking recess and can cooperate with another element, e.g. the support element or a separately provided abutment element, of the locking device.

-10 -Provision is made in a further possible embodiment that the second ballast element is only connectable to the first ballast element via the at least one locking device, in particular via at least two locking devices, and is arranged below the first ballast element in the connected state. The second ballast element here hangs, in particular only, at the locking device or devices and is connected via it or them or via the first ballast element to the counterweight device.

The present invention furthermore relates to a mobile crane having a system in accordance with the invention. The mobile crane additionally comprises a counterweight device, that is in particular arranged at a rotatable superstructure, for receiving a counterweight comprising at least two ballast elements that are connectable and lockable by the system in accordance with the invention. The same advantages and properties obviously result here as for the system in accordance with the invention so that a repeat description will be dispensed with at this point.

The counterweight device preferably comprises one or more ballasting cylinders for raising at least one ballast element to the counterweight device. The mobile crane in accordance with the invention can furthermore be a so-called high speed crane that can be driven on public roads at relatively high speeds of, for example, up to 80 k.p.h. and in which high acceleration and braking forces can thus occur that put corresponding strain on the locking device. The support element therefore has to be designed accordingly.

The present invention further relates to a method of connecting and locking two ballast plates of a system in accordance with the invention. The method comprises the following steps: guiding, preferably from below, the second ballast plate to the first ballast plate optionally fastened to the counterweight device so that the mutually facing openings of the first and second cutouts are covered by one another and form a continuous cutout; pushing, in particular vertically pushing, the locking device into the cutout formed by the first and second cutouts until it contacts an abutment; moving the locking device into the locked position, with this movement at least comprising a rotation of the locking device about the longitudinal axis of the carrier; and locking or securing the locking device in the locked position by means of the securing mechanism.

The same advantages and properties obviously result here as for the system in accordance with the invention so that a repeat description will be dispensed with at this point. The unlocking of the ballast elements substantially takes place by carrying out these steps in reverse order.

Provision is made in a possible embodiment of the invention that the moving of the locking device into the locked position after the rotation about the longitudinal axis of the carrier comprises a raising of the locking device until the locking element and/or the support element abut/abuts an abutment. In particular no raising is possible in an angular range between the release position and the locked position.

The abutment is preferably formed by the upper wall of a recess (for example the above-described locking recess), with the locking device only having been raised sufficiently on the contacting of this abutment and the securing mechanism thus becoming actuable (or the securing element placeable) so that the locking device is locked in the locked position.

Further features, details, and advantages of the invention result from the embodiments explained in the following with reference to the Figures. There are shown: Figure 1: a side view of a mobile crane in accordance with an embodiment of the invention; -12 -Figure 2: an enlarged detail of the counterweight device of the mobile crane with an embodiment of the system in accordance with the invention in a perspective view; Figure 3: an embodiment of the locking device in a perspective view; Figures 4-6: perspective sectional views through the first and second ballast elements with different positions of the locking device in accordance with Figure 3 on the locking of the ballast elements; Figure 7: an alternative embodiment of the locking device in a perspective view; and Figure 8: a lateral sectional view through the first ballast element with the locking device in accordance with Figure 7 introduced into the first cutout.

Figure 1 shows an embodiment of a mobile crane 1 in a lateral view having a system in accordance with the invention for locking ballast elements of the counterweight arrangement 5. The mobile crane 1 has an undercarriage 2 with a wheeled chassis that comprises a plurality of wheel axles 2a with wheels 2b. The weight of the mobile crane 1 is therefore distributed over the different wheel axles 2a.

A superstructure 6 is rotatably supported about a vertical axis on the undercarriage 2. The superstructure 6 has a luffable telescopic boom 4 and a counterweight arrangement 5 (also called superstructure ballast or simply a counterweight) in the rear region. The rear region of the superstructure frame structure forms a counterweight device 6 to which a first ballast element 10 is fastenable via connection means 7 (in particular screw and/or bolt connections). Ballast elements can be raised from special placement surfaces at the undercarriage 2 by means of hydraulic ballasting cylinders, not shown in any more detail here, and moved to the counterweight device 6 to equip the superstructure ballast 5. A base counterweight -13 -plate 8 on which ballast plates can be stacked and can then be raised to the superstructure 6 by means of the ballasting cylinders is located in a center region of the undercarriage 2 for this purpose.

To be able to vary and better utilize the axle loads when driving the mobile crane 1 in public road traffic, a plurality of ballast elements, at least two plate-like ballast element or ballast plates 10 and 12 (see Figure 2) in the present case, can be fixedly connected to the steel construction of the superstructure 6 for the transport and therefore remain on the superstructure 6.

Figure 2 shows the counterweight device 6 of the superstructure 6 in a perspective view with two ballast plates 10, 12 fastened thereto via connection means 7. Here, the first (upper) ballast plate 10 is directly connected to the counterweight device 6 while the second (lower) ballast plate 12 is connected to the first ballast plate 10 and locked via a plurality of locking devices 20 (four in the present case). Where required, the second ballast plate 12 can be removed from the superstructure 6 and only the first ballast plate 10 can be connected thereto. Both or neither of the ballast plates can likewise remain at the superstructure 6. The ballast plates 10,12 have T grooves 30 at the side into which further ballast elements can be hooked as hook-in ballast.

In Figure 3, one of the locking devices 20 that are used to connect and lock the two ballast plates 10, 12 to one another is shown in a perspective view. The locking device 20 has an elongate substantially cylindrical carrier 200. A latch-like or bar-like locking element 202 that has a substantially rectangular contour in a plan view is located at an end (called the lower end in the following) of the carrier 200. A pivotable handle 28 via which the locking element 20 can be raised and actuated (i.e. in particular pushed in, pulled out, and rotated) is located at the other end of the carrier 200.

A sleeve-like abutment element 230 having a central recess that is designed as a bore that extends in parallel with the elongate carrier axis and in which the carrier 200 is displaceably guided relative to the abutment element 230 is located below the -14 -handle 208. The abutment element 230 substantially has the shape of a reversed "T" seen from the side. A support element 204 that is likewise of a latch shape or bar shape and that has a substantially rectangular contour in a plan view is arranged at the carrier 200 between the abutment element 230 and the locking element 202. The locking and support elements 202, 204 are formed in one piece with the carrier 200 and project in a radial direction away from the carrier 200 at both sides, i.e. in a winglike manner. The locking and support elements 202, 204 are here aligned in parallel with one another and have, at their front faces, respective contact surfaces 203, 205 that are slightly convexly swept.

The locking device 20 furthermore has a securing mechanism 206 that comprises a bolt-like securing element 210 or a securing bolt 210. The securing bolt 210 is supported in a securing cutout 234 of the abutment element 234 that extends transversely to the longitudinal carrier axis, that is formed as a bore, and that intersects its central recess. The carrier 200 has at least one corresponding transverse bore 201 (cf. Figure 5) that covers the securing cutout 234 in a locked position of the locking device 20 so that the securing bolt 210 can be pushed through and immovably fixes the abutment element 230 at the carrier 200. A lever 220 by means of which the securing bolt 210 is simply and comfortably displaceable is located at an end of the securing bolt 210.

The plug-in bolt or securing bolt 210 is securable or lockable in the completely inserted position by means of a securing element locking means 212 designed as a folding securing plug here so that it cannot slide out of the securing cutout 234 in an unwanted manner. Both the lever 220 and the folding securing plug 212 are secured at the locking device and permanently connected thereto via securing members 214. There are therefore no loose parts; the locking device 20 forms a unit.

Figures 4 -6 show different positions of the vertically acting locking device 20 on the locking of the first and second ballast plates 10, 12, each in a perspective sectional view through the ballast plates 10, 12 and the locking device 20.

-15 -The first ballast plate 10 has a continuous first cutout, that is a cutout 100 that extends from the upper side to the lower side. The second ballast plate 12 also has such a continuous cutout that is called the second cutout 120 here. In the connected or locked state, the first and second cutouts 100, 120 cover one another and form a continuous cutout through both ballast elements 10, 12 into which the locking device 20 is pushable in the vertical direction. Both the first and second cutouts 100, 120 each have sections of different diameters.

The sections 106 and 124 are adapted to the geometry of the locking and support elements 202, 204 and provide that the locking device 20 is only pushable into the cutouts 100, 120 in one single alignment that can be seen in Figures 4 and 5. In the embodiment shown here with a bar-like locking element 202, the sections 106 and 124 also have rectangular cross-sections.

In Figure 5, the locking device 20 can be seen in a completely pushed in position, i.e. at a maximum depth, that is called the release position. The support element 204 is located within a recess 108, 122 having a diameter increased in comparison with the section 106. This recess is formed by a recess of the first cutout 100 opening into the lower side of the first ballast plate 10 and called a support recess 108 here and by a recess 108 of the second cutout 120 adjoining it and opening into the upper side of the second ballast plate 12. The section 106 can also be called an opening of the support recess 108. The recesses 108 and 122 can have a circular cross-section.

A constricted region 124 that merges into a recess 128 again having an enlarged diameter adjoins the recess 122 of the second cutout 120. The recess 128 that in particular opens into the lower side of the second ballast plate 12 can have a circular cross-section. In the transition region between the recesses 124 and 128, a groove 126 is formed that is open toward the recess 128 (that is toward the bottom) and that is formed complementary to the locking element 202 (that is latch shaped or bar shaped having a substantially rectangular cross-section) so that the locking element 202 fits exactly in this groove 126 called a locking recess. The region 124 can also be called an opening of the locking recess 126.

-16 -The long axis of the locking recess 126 extends (in a plan view) transversely to the long axis of the region 124 or of the locking element 202 in the release position. So that the locking element 202 fits into the locking recess 126, the locking device 20 has to be rotated by 90° starting from the release position. The position of the locking device 20 in which the locking element 202 is located in the locking recess 126 and the support element is located in the support recess 108 is called the locked position. The two ballast plates 10, 12 are connected to and locked with one another in the locked position. In this respect, the second ballast plate 12 lies via the upper wall of the locking recess 126 on the upper support surface 207 of the locking element 202.

The locking device 20 receives the total weight of the second ballast plate 12 and lies via the downwardly facing abutment surface 232 of the abutment element 230 on the first ballast element 10, expressed more exactly on an upper support surface 105 of a depression 104 upwardly adjoining the region 106. The depression 104 in turn merges into a recess 102 opening into the upper side of the first ballast plate 10, in which recess 102 the handle 208 and the abutment element 230 are (at least partially sunk) in the locked position. No parts thereby project beyond the first ballast plate 10 (or only negligibly) in the locked state.

If, for example, the crane operator decides after a crane deployment that he would like to move the mobile crane 1 with two counterweights or ballast plates 10, 12 away from the first deployment site in public road traffic, he will connect the ballast plates 10, 12 via the locking device(s) 20. For this purpose, he takes up the locking device at the pivotable handle 208 as shown in Figure 4. He aligns the locking element 202 corresponding to the section 106 of the first cutout 100 in the first ballast plate 10 and introduces the locking element 202 formed as a transverse latch together with the carrier 200 into the corresponding cutouts 100, 120 in the ballast plates 10, 12. This takes place for so long until the abutment surface 232 of the abutment element 230 abuts the provided abutment or support surface 105 of the depression 104.

-17 -If the plug-in bolt 210 is still plugged in, it is pulled out of the transverse cutout 201 by using the lever 220. The length of the securing member 214 here ideally prevents the securing pin 210 from being able to be completely pulled out of the securing cutout 234. The carrier 200 can now be further lowered. In the completely pushed in position (see Figure 5), the locking element 202 is located beneath the locking recess 126 in the recess 128.

The locking device 20 can now be rotated in its totality out of the release position by 900 so that the locking element 202 is aligned in parallel with the groove 126. The locking element 202 is inserted from below into the locking recess 126 via a repeat raising of the locking device 20 at the handle 208 until the upper contact surface 207 abuts the upper wall of the locking recess 126. The transverse cutout 201 and the securing cutout 234 now again cover one another so that the plug-in bolt 210 can be plugged in again (cf. Figure 6).

In this locked position, the ballast plates 10, 12 are in particular initially still held via the ballasting cylinders (not shown) in the counterweight arrangement 5. The ballast plates can, however, also be separate. After letting down the ballasting cylinders, the ballast plates 10, 12 lie on their abutments, the first ballast plate 10 at its connection to the superstructure 6 or to the counterweight arrangement 5 and the second ballast plate 12 at the surface 203 for the force introduction at the locking element 202. The force flow takes place via the carrier 200, the plug-in bolt 210 and the abutment element 230 into the first ballast plate 10.

The mobile crane 1 with the remaining ballast plates 10, 12 can now independently take up the other ballast weights placed on the base counterweight plate 8 from the undercarriage 2 via its boom 4 and can place them on a separate transport vehicle for the road travel. The mobile crane 1 is subsequently moved into a state in which it can be driven on public roads. The great mass of the ballast plates 10 and 12 remains on the steel construction of the superstructure 6.

-18 -The mobile crane 1 in particular drives as a high speed crane in public traffic. This means that the ballast plates 10, 12 all experience accelerations at a speed in the range, for example, of up to 80 k.p.h. These accelerations are inter alia caused by braking, accelerating, and cornering, driving over crests and hollows, and by vibrations. The locking device 20 is accordingly configured to take up large forces in the direction of travel and transversely to the direction of travel in a safe manner in public traffic. The latter can be aligned horizontally or vertically. All conceivable superpositions can logically also be considered.

The support element 204 is provided for this purpose. It is intended to take up the braking and acceleration forces at least in the direction of travel. In the locked position, the support element 204 is received for this purpose in the support recess 108 of the first cutout 100 of the first ballast plate 10. The dimensions of the support recess 108 are designed such that less play is present between its wall that acts as a counter-support element and the front or contact surfaces 205 of the support element 204 The second ballast plate 20 lies on the support surface 207 of the locking element 202 and introduces its weight force. Sticking friction is hereby produced. If the braking and acceleration forces in the direction of travel exceed this sticking friction, the second ballast plate 12 slips on the support surface 207 until the front or contact surface 203 of the locking element 202 abuts the lateral wall of the locking recess 126, that acts as a counter-locking element, and establishes a form fit.

Independently of how the forces are introduced into the locked connection, they have to be led off again. This should take place via a force pair. The lower force of the force pair is introduced into the first ballast plate 10 via the support element 204 and its contact surfaces 205. The upper force of the force pair is either introduced into the first ballast plate 10 via the friction between the abutment surface 232 of the abutment element 230 or is introduced into the lateral wall of the depression 104 via the outer jacket surface of the abutment element 230. The carrier 200 is consequently bent under (changing) load and correspondingly dimensioned.

-19 -The forces transverse to the direction of travel generate a torque that is transmitted via a force pair in the abutment surfaces 232 of the abutment elements 230. At least two locking devices 20, preferably at least three, have to be present overall for this purpose to lock the ballast plates 10 12. The transverse forces are transmitted via friction.

No further tool such as a wrench or the like is required to connect the ballast elements 10, 12. The handle 208 is pivotable so that is does not project too highly from the first ballast element 10 or the upper recess 102. The latter additionally takes up the associated elements of the plug-in bolt 210 and is sufficiently large in dimension for a comfortable operation.

Various slopes are provided in the ballast plates 10, 12 at the transitions between sections of different diameters that, in particular together with the slopes provided at the locking and support elements 202, 204, and the carrier 200 facilitate an introduction of the locking device 20 into the cutouts 100, 120. A rotation of the locking device 20 in its locked position is securely prevented by the shape of the locking recess or groove 126. If the locking element 202 is below the groove 126, the locking device 20 can be rotated. This required rotation also takes along the support element 204.

The position of the abutment element 230 is ensured via the position depression 104 and corresponding lateral flattened portions or planar contact surfaces 233. If the abutment element 230 and the carrier 200 are positioned sufficiently exactly with respect to one another, the plug-in bolt 210 can be easily plugged in The time at which the locking device 20 is attached is of no significance. It can take place before or after the installation of the ballast elements 10, 12. This means that the two ballast elements 10, 12 can, for example, only be locked by means of the locking device(s) 20 and then attached to the counterweight device 5 via the connection means 7 or that the first ballast element 10 can first be fastened to the -20 -superstructure 6 and then the second ballast element 10 can be attached to and locked at the first ballast element 10 via the locking device(s) 20.

To reduce to great a play after the plugging in of the plug-in bolt 210, a setting possibility can be provided. It can be setting metal sheets, as required, that are introduced or placed between the first ballast plate 10 and the abutment element 230.

An alternative embodiment of the locking device 20' in accordance with the invention is shown in Figures 7 and 8. In this respect, the locking element 202' is not bar-shaped with an (in a plan view) rectangular contour), but rather has a triangular shape in a plan view (in particular in the form of an equilateral triangle). Two support elements 204' that have a circular shape (in a plan view) are furthermore provided here. A force transmission thereby results by a force pair, with the total outer periphery servicing as a contact surface.

A holder 250 is furthermore provided that is installable or installed into the first cutout 100 and that has the counter-abutments for the support elements 204'. The holder 250 in this embodiment comprises two or more annular washers 251 that are connected via a plurality of screws extending in the vertical direction, that are arranged in parallel above one another, and whose central openings are adapted to the outer diameters of the support elements 204' and furthermore have three recesses spaced apart from one another by 120° to lead through the triangular locking element 202' in the release position. The support elements 204' are at the level of the annular washers 251 in the locked position.

A setting metal sheet 22 is inserted between the upper annular washer 251 and an annular projection/abutment of the first cutout 100'. The pushing in and rotating of the locking device 20' works in an analog manner to the first embodiment, with here no rotation about 90° taking place into the locked position, but rather by 60°.

Reference numeral list: 1 mobile crane -21 - 2 undercarriage 2a axle 2b wheel 4 boom counterweight arrangement 6 superstructure 7 connection means 8 base counterweight plate first ballast element 12 second ballast element locking device T groove first cutout 102 recess 104 recess support surface 106 section of the first recess/opening 108 support recess second cutout 122 recess 124 section of the second cutout/opening 126 locking recess (groove) 127 wall 128 recess carrier 201 transverse cutout 202 locking element 203 contact surface 204 support element 205 contact surface 206 securing mechanism 207 support surface -22 -208 handle 210 securing element 212 securing element locking means 214 securing member 220 lever 230 abutment element 232 abutment surface 233 contact surface 234 securing cutout 250 holder 251 annular washer 252 setting metal sheet

Claims (18)

1. -23 -Claims 1. A system for releasably connecting and locking two ballast elements, in particular plate-like ballast elements (10, 12) of a mobile crane (1), comprising: 1 a first ballast element (10) having at least one continuous first cutout (100) that is fastenable to a counterweight device (6) of the mobile crane (1); 2 a second ballast element (12) reversibly connectable to the first ballast element (10) and having at least one second cutout (120) that covers the at least one first cutout (100) of the first ballast element (10) in the connected state; and 3 at least one locking device (20) for releasably connecting and locking the two ballast elements (10, 12) to one another, the locking device (20) comprising the following: 3.1 an elongate carrier (200) pushable between the first and second cutouts (100 120); 3.2 a locking element (202) that is arranged at the carrier (200) and that cooperates with a counter-locking element of the first and/or second -24 -ballast elements (10, 12) in a locked position for locking the two ballast elements (10 12); 3.3 a support element (204) that is arranged at the carrier (200), that is spaced apart from the locking element (202), and that is configured to take up forces acting on the first and/or second ballast elements (10, 12) in the locked position transverse to the longitudinal axis of the carrier (200); and 3.4 a securing mechanism (206) by means of which the locking device (20) is fixable in the locked position.
2. A system in accordance with claim 1, characterized in that the support element (204) is configured to cooperate with a counter-support element formed in the first cutout (100) and to introduce forces acting transversely to the longitudinal axis of the carrier (200) in the locked position, with the counter-support element preferably being a wall of a support recess (108) that is formed in the first cutout (100) and in which the support element (204) is located in the locked position.
3. 3. A system in accordance with claim 1 or claim 2, characterized in that the support element (204) has at least one contact surface (205) that is disposed opposite a wall of the first cutout (100), in particular of a support recess (108) formed in the first cutout (100), in the locked position and that is configured to contact the wall on an occurrence of a force acting transversely to the longitudinal axis of the carrier (200) on the first and/or second ballast elements (10, 12) and to introduce the force into the first ballast element (10).
4. 4. A system in accordance with one of the preceding claims, characterized in that the carrier (200), the locking element (202), and the support element (204) are fixedly connected to one another and are preferably formed in one piece.
5. A system in accordance with one of the preceding claims, characterized in that the counter-locking element is provided in a locking recess (126) formed in the second cutout (120) and has an opening (124) having a non-circular cross-section and that the locking element (202) projects beyond the outer contour of the carrier (200) in a plan view and likewise does not have any circular cross- -25 -section, with the locking element (202) being pushable through the opening (124) in a release position and does not pass through the opening (124) in the locked position that can in particular be achieved by a rotation of the locking device (20) about the longitudinal axis of the carrier (200), and with the locking element (202) preferably being configured to form a form fit with a wall (127) of the locking recess (126) in the locked position.
6. 6. A system in accordance with claim 5, characterized in that the locking element (202) has an outer contour that is rectangular or triangular in a plan view, with the opening (12) having a complementary rectangular or triangular contour through which the locking element (202) is pushable in the release position, and with the support element (204) preferably having an outer contour corresponding to the locking element (20) in a plan view.
7. 7. A system in accordance with one of the preceding claims, characterized in that the first cutout (100) and/or the second cutout (120) does/do not have any circular cross-section sectionally..
8. 8. A system in accordance with one of the preceding claims, characterized in that the locking element (202) is arranged at one end of the carrier (200), the securing mechanism (206) at the oppositely disposed end of the carrier (200), and the support element (204) between the securing mechanism (206) and the locking element (202).
9. 9. A system in accordance with one of the preceding claims, characterized in that a handle (208) is arranged at the end of the carrier (200) disposed opposite the locking element (202) for raising and/or moving the locking device (20) from a release position into the locked position and vice versa, said handle(208) preferably being pivotably supported at the carrier (200).
10. A system in accordance with one of the preceding claims, characterized in that; the locking element (202) has a support surface (207) oriented transversely to the longitudinal axis of the carrier (200) on which the second ballast element (12) lies in the locked position, with the locking device (20) and the second -26 -ballast element (12) preferably being configured such that the total weight force of the second ballast element (12) is taken up by the at least one locking device (20) and is conducted into the first ballast element (10) and/or into the counterweight device (6) of the mobile crane (1).
11. 11 A system in accordance with one of the preceding claims, characterized in that the securing mechanism (206) comprises a securing element (210), in particular of bolt shape, that is pushable into a securing cutout (234) extending transversely to the longitudinal axis of the carrier (200) and is releasably lockable in a securing position by a securing element locking means (212), with the securing element (210) and/or the securing element locking means (212) preferably being inseparably connected to the carrier (200).
12. 12 A system in accordance with one of the preceding claims, characterized in that the locking device (20) comprises an abutment element (230) that is displaceably supported at the carrier (200) relative thereto and has an abutment surface (232) contacting the first ballast element (10) in the locked position, with the carrier (200) preferably being displaceably supported in a central cutout of the abutment element (230).
13. 13 A system in accordance with claims 11 and 12, characterized in that the abutment element (230) has a transverse cutout (201) that extends transversely to the longitudinal axis of the carrier (200) through the central cutout and is movable into coverage with the securing cutout (234), through which the securing element (212) is pushable, in the locked position.
14. 14 A system in accordance with one of the preceding claims, characterized in that a locking abutment is provided that is configured to block an independent release of the locked position, with the locking abutment preferably cooperating with the locking element (202) in the locked position and being formed by a lateral wall of a locking recess (126) that is formed in the second cutout (120) and in which the locking element (202) is located in the locked position, and that -27 -in particular has an inner contour complementary to the outer contour of the locking element (202).
15. A system in accordance with one of the preceding claims, characterized in that the second ballast element (12) is only connectable to the first ballast element (10) via the at least one locking device (20), in particular via at least two locking devices, (20,) and is preferably arranged below the first ballast element (10) in the connected state.
16. 16 A mobile crane (1) having a counterweight device (6) that is in particular arranged at a rotatable superstructure (3) for receiving a counterweight (5) comprising at least two ballast elements (10, 12) and having a system in accordance with one of the preceding claims, wherein the counterweight device (6) preferably comprises one or more ballasting cylinders to raise at least one ballast element (10, 12) to the counterweight device (6).
17. 17 A method of connecting and locking two ballast plates (10, 12) of a system in accordance with one of the claims 1 to 15, the method comprising the steps: - guiding the second ballast plate (12) to the first ballast plate (10) fastened to the counterweight device (6) so that the mutually facing openings of the first and second cutouts (100, 120) cover one another.- pushing the locking device (20) into the cutout formed by the first and second cutouts (100, 120) until it contacts an abutment (232); - moving the locking device (20) into the locked position, with this movement at least comprising a rotation of the locking device (20) about the longitudinal axis of the carrier (200); and locking the locking device (20) in the locked position by means of the securing mechanism (206).
18. 18 A method in accordance with claim 17, characterized in that the moving of the locking device (20) into the locked position after the rotation abut the longitudinal axis of the carrier (200) comprises a raising of the locking device (20) until the locking element (202) and/or the support element (204) abuts/abut -28 -an abutment that is preferably formed by the upper wall of a recess (126), with the securing mechanism (206) only being actuable at this abutment and the latching device (20) being lockable in the locked position.