EP1473267A1 - Crane ballasting device - Google Patents

Abstract

The device has a gripper (2) for handling stackable ballast blocks (3), and a connecting unit placed between the gripper and a block. The unit has two opposite gripping hooks assembled in region of ends of a swing bar of the gripper and cooperates with transverse axis of the block. A back part of each hook is attached to a sling by which the gripper is suspended at a hoisting cable, where each hook is associated to a bolt.

Description

The present invention relates to the technical field of cranes, especially tower cranes. This invention relates, more particularly, a device for ballasting such a crane with the aid of stackable concrete blocks on a crane base frame, the device for weighting combining the ballast blocks and means of handling these blocks, allowing the establishment of ballast blocks without intervention manual.

• sur le dessus des blocs de lest, des crochets orientés vers l'extérieur et logés à l'intérieur de cavités de forme adaptée au guidage latéral de roulettes du préhenseur et au débattement maximal du préhenseur ;
• un préhenseur relié (en utilisation) à un câble de levage actionné par un treuil de la grue, le préhenseur étant composé de deux bras articulés entre eux par l'une de leurs extrémités, et munis à leur autre extrémité respective d'une partie ouverte prévue pour s'engager dans un crochet des blocs de lest, cette autre extrémité étant aussi pourvue de roulettes, tandis que des leviers articulés sont prévus pour commander l'ouverture ou la fermeture des bras du préhenseur ;
• un système de centrage des blocs de lest, qui utilise d'une part des excroissances de profil trapézoïdal sur la face supérieure de ces blocs et des cavités correspondantes sur la face inférieure des mêmes blocs, une cavité d'un bloc supérieur étant prévue pour coopérer avec une excroissance d'un bloc inférieur, et d'autre part des étriers prévus sur un côté des blocs de lest, à leur partie supérieure, et des réservations correspondantes ménagées à la partie inférieure des blocs, chaque réservation d'un bloc supérieur étant prévue pour coopérer avec un étrier d'un bloc inférieur, les étriers constituant aussi des barreaux d'échelles utilisées par les opérateurs.

The published European patent application EP 1205422 A1 already describes a device for gripping the ballast blocks intended to be stacked at the base of a crane, in particular of a tower crane, this known device combining:

• on the top of the ballast blocks, hooks oriented outwards and housed inside cavities adapted to the lateral guide wheels of the gripper and the maximum movement of the gripper;
• a gripper connected (in use) to a hoisting rope actuated by a winch of the crane, the gripper being composed of two arms articulated to each other by one of their ends, and provided at their respective end with an open part provided to engage a hook of the ballast blocks, this other end being also provided with wheels, while articulated levers are provided to control the opening or closing of the arms of the gripper;
• a system for centering the ballast blocks, which uses, on the one hand, trapezoidal profile excrescences on the upper face of these blocks and corresponding cavities on the lower face of the same blocks, a cavity of an upper block being provided to cooperate with a protrusion of a lower block, and secondly stirrups provided on one side of the ballast blocks, at their upper part, and corresponding reservations made at the bottom of the blocks, each reservation of an upper block being provided to cooperate with a caliper of a lower block, the stirrups also constituting ladder bars used by the operators.

• La forme requise des blocs de lest est particulièrement difficile à réaliser, notamment en ce qui concerne les cavités avec paroi en pente, le positionnement précis des crochets dans ces cavités, les excroissances et réservations de profil trapézoïdal, et la mise en place des étriers latéraux ainsi que la réalisation des réservations correspondantes.
• Les roulettes de guidage, prévues aux extrémités des bras du préhenseur, constituent des parties fragiles, exposées à des chocs en cours d'utilisation.
• L'ensemble des leviers utilisés pour le déverrouillage des blocs de lest possède une faible fiabilité, compte tenu des positions relatives de ses axes d'articulation.
• Le système de centrage est complexe, dans la mesure où il nécessite des éléments distincts pour le positionnement relatif longitudinal et le positionnement relatif transversal des blocs de lest empilés.
• Lors de l'utilisation du dispositif, la sécurité de l'opérateur n'est pas garantie, si celui-ci engage un bras ou un doigt dans les pièces articulées.

This known device has various disadvantages:

• The required shape of the ballast blocks is particularly difficult to achieve, in particular as regards the cavities with sloping wall, the precise positioning of the hooks in these cavities, the excrescences and reservations of trapezoidal profile, and the installation of the lateral stirrups. as well as the realization of the corresponding reservations.
• The guide rollers, provided at the ends of the arms of the gripper, are fragile parts, exposed to shocks during use.
• The set of levers used for unlocking the ballast blocks has a low reliability, given the relative positions of its axes of articulation.
• The centering system is complex in that it requires separate elements for longitudinal relative positioning and transverse relative positioning of the stacked ballast blocks.
• When using the device, the safety of the operator is not guaranteed, if it engages an arm or a finger in the articulated parts.

Overall, even though it claims to require only one operator to carry out the ballasting, the device known here evoked therefore remains complex and expensive, and of a delicate and dangerous use.

• permette une réalisation des opérations de lestage et de délestage, c'est-à-dire de mise en place et de retrait des blocs de lest, par un seul opérateur avec un gain effectif de temps et de main d'oeuvre, et en toute sécurité pour cet opérateur ;
• utilise des blocs de lest de configuration simple, pouvant être produits industriellement de façon économique ;
• comporte un système simple et précis pour le centrage des blocs de lest les uns par rapport aux autres ;
• comporte aussi un système simple de centrage des moyens de préhension sur un bloc de lest à manipuler ;
• constitue globalement un dispositif simple et robuste, donc fiable, dont le principe repose en particulier sur un fonctionnement par gravité des pièces articulées.

The present invention aims at eliminating all of the above-mentioned disadvantages, and its main goals are therefore to provide a crane ballast device which:

• allow a realization of the operations of ballasting and unloading, that is to say of setting up and withdrawal of the blocks of ballast, by a single operator with an effective gain of time and manpower, and in all security for this operator;
• uses ballast blocks of simple configuration, which can be industrially produced economically;
• has a simple and precise system for centering the ballast blocks with respect to each other;
• also comprises a simple system for centering the gripping means on a ballast block to be handled;
• overall constitutes a simple and robust device, so reliable, whose principle is based in particular on a gravity operation articulated parts.

For this purpose, the subject of the invention is a weighting device for crane, in particular for tower cranes, of the kind here concerned, that is to say combining stackable ballast blocks on a crane base frame and a gripper for the handling of the ballast blocks, the gripper being intended to be connected, in use, to a means of handling, this device comprising in a known manner non-permanent connection means by gripping between the gripper and a block of ballast, as well as means for the centering of the stacked ballast blocks, relative to one another, and said essentially characterized by the fact that the connecting means non-permanent aforementioned include two opposite grip hooks pivoted, about horizontal axes, in the end regions of a gripper lifter, each gripping hook having, on one side of its pivot axis, a catching nose adapted to cooperate with a transverse axis placed in a corresponding housing of a block of ballast, and the other side of its pivot axis, a rear part attached to a sling by which the gripper is suspended from the hoisting rope, at each gripping hook being associated with a latch carried by the rudder and provided to temporarily hold the corresponding gripping hook in release position of the transverse axis.

Thus, the invention provides a weighting device which is of use particularly easy, the device comprising hooks mounted on the gripper and no longer on the ballast blocks, and requiring only Manual intervention Unlocking the hooks before lifting a block while the other movements are controlled by gravity and by the action of the slings on the hooks of prehension.

In a simple embodiment, the rudder is constituted to from two parallel bars or sections, secured to one another in between them a longitudinal gap, so as to form the two ends of the yoke of the yokes used for the articulation of the two hooks suspension.

On the two bars or profiles of the rudder are advantageously vertical protection plates, which protect the deflection of the rear part of the gripping hooks, for safety of the operator.

Preferably, the rear part of each gripping hook itself, or carries, a counterweight, which allows the hooks to grasping to automatically release the transverse axes of the ballast block, when it is placed and the slings relax.

Advantageously, each sling forms, with the longitudinal axis of the corresponding gripping hook, an angle of less than 180 °, which ensures the holding in position of the gripping hooks on the axes cross-section of the ballast block, under the effect of the weight of this block.

In an advantageous embodiment, each lock of the gripper is a latch pivoted around a horizontal axis carried by the rudder, the bolt having a bent shape, with a lower part forming a counterweight, and an upper part forming a locking nose and provided with a ramp, intended to cooperate with a raised control finger by the rear part of the corresponding gripping hook.

According to another aspect of the invention, the ballast blocks, made essentially made of concrete, each have two gripping parts embedded in the concrete, each of which delimits a dwelling suitable for receive a gripping hook, each metal gripping part being provided with a transverse axis, crossing the housing which it delimits and intended to cooperate with the hooking nose of a gripping hook engaged in this housing.

Under the spreader are advantageously fixed two brackets of positioning, provided to cooperate, respectively, with the edges upper housing delimited by the two gripping parts of a ballast block; these brackets ensure the centering of the gripper on a block of ballast, when the rudder lands on the upper face of the block of ballast.

In a preferred embodiment, the means for the centering stacked ballast blocks, relative to one another, include on each block of ballast conical centering pins, which protrude above the upper face of the ballast block, and corresponding housings of flared shape, in particular conical or pyramidal, which open into the lower face of the ballast block. These pieces and complementary dwellings ensure, by themselves, the relative positioning longitudinal and transversal two directly stacked ballast blocks, and they allow for certain tolerances in manufacturing and laying blocks.

According to an advantageous embodiment, from the point of view of the manufacture of the device and its accuracy of realization, the centering pins and the corresponding housings belong to centering parts each metal centering part extending vertically on one side of a metal grip part, and being attached thereto to form a single metal insert, embedded in the concrete of the ballast block.

Finally, the rudder is advantageously provided, at its ends, of rings provided for receiving a guide rope, usable in the course of handling a block of ballast, hooked under the rudder, the rope being scheduled to be held by an operator who remains posted on the ground.

Figure 1 est une vue d'ensemble, en perspective, d'un préhenseur d'un dispositif conforme à la présente invention ;

Figure 2 est une vue de face montrant l'ensemble du dispositif selon l'invention, avec le préhenseur se présentant au-dessus d'un bloc de lest ;

Figure 3 est une vue à échelle agrandie du détail A de la figure 2, montrant plus particulièrement un crochet du préhenseur en position verrouillée ;

Figures 4, 5 et 6 sont des vues de détail similaires à la figure 3, illustrant des positions successives du crochet au cours de l'utilisation du dispositif, plus particulièrement dans la phase d'accrochage d'un bloc de lest ;

Figure 7 est une vue de face similaire à la figure 2, montrant le préhenseur lors du levage du bloc de lest ;

Figure 8 est une autre vue de face illustrant le guidage du bloc de lest en cours de manutention ;

Figure 9 est encore une autre vue de face, illustrant l'empilage et le centrage des blocs de lest ;

Figure 10 est une vue de détail, illustrant le début du décrochage automatique du bloc de lest posé ;

Figure 11 est une vue similaire à la figure 10, illustrant la fin du décrochage automatique du bloc de lest ;

Figure 12 montre, en vue de face, l'ensemble du dispositif avec son préhenseur décroché du dernier bloc de lest posé ;

Figure 13 représente, en perspective, un insert métallique du bloc de lest.

The invention will be better understood from the description which follows, with reference to the attached schematic drawing showing, by way of example, an embodiment of this crane ballast device:

Figure 1 is an overall perspective view of a gripper of a device according to the present invention;

Figure 2 is a front view showing the entire device according to the invention, with the gripper being above a block of ballast;

Figure 3 is an enlarged view of the detail A of Figure 2, more particularly showing a hook of the gripper in the locked position;

Figures 4, 5 and 6 are detail views similar to Figure 3, illustrating successive positions of the hook during use of the device, more particularly in the attachment phase of a ballast block;

Figure 7 is a front view similar to Figure 2, showing the gripper when lifting the ballast block;

Figure 8 is another front view illustrating the guide of the ballast block being handled;

Figure 9 is yet another front view, illustrating the stacking and centering of the ballast blocks;

Figure 10 is a detail view, illustrating the beginning of the automatic stall of the weighted weight block;

Figure 11 is a view similar to Figure 10, illustrating the end of the automatic stall of the ballast block;

Figure 12 shows, in front view, the entire device with its gripper unhooked last ballast block placed;

Figure 13 shows, in perspective, a metal insert of the ballast block.

The crane weighting device, shown in the drawing, consists of a gripper 2 and ballast blocks 3, the gripper 2 being adapted to ballast blocks 3.

The gripper 2 is represented as a whole in FIGS. and 2, with FIG. 3 representing on a larger scale a detail A of this gripper 2.

The gripper 2 comprises a lifter 4, constituted from two "U" shaped sections 5 and 6 parallel, opposed to one another, and secured one with the other, a gap 7 being formed between the two sections 5 and 6, over the entire length of these. Thus slightly spaced, the two sections 5 and 6 form two clevises respectively located at both ends of the lifter 4.

On the lower part of the rudder 4, therefore under the wings lower sections of the two sections 5 and 6 are welded two transverse brackets 8 and 9 respectively.

On the upper part of the rudder 4, more particularly on the two sections 5 and 6 are welded protective plates 42 triangular, vertical (omitted in Figure 1).

At each end, in its screed portion, the rudder 4 has two coaxial holes, formed respectively in the souls vertical sections of the two sections 5 and 6, and receiving a hinge axis horizontal 10 for a pivoting grip hook (described below).

Towards each end, but behind the coaxial holes receiving the hinge axis 10 above, the spreader 4 comprises two other coaxial holes, respectively formed in the vertical webs of the two sections 5 and 6, and receiving a horizontal hinge axis 11 for a latch pivoting (described below).

At each of its ends, the rudder 4 is still equipped with two horizontal rings, respectively 12 and 13 (not indicated on the Figure 1 but visible in the following figures). Each ring 12 or 13, soldered on the end portions of the two sections 5 and 6, is provided for receive a handling guide rope 14 of a ballast block 3, as illustrated in Figure 8.

The gripper 2 comprises two gripping hooks, respectively 15 and 16, articulated symmetrically on the horizontal axes 10 carried by both ends of the rudder 4, each hook 15 or 16 thus crossing the gap 7 formed between the two sections 5 and 6.

• une partie avant, située sous le palonnier 4, et formant un bec d'accrochage 17 dirigé vers l'intérieur ;
• une partie arrière 18, située au-dessus du palonnier 4, et faisant office de contrepoids ;
• dans la partie arrière 18, un doigt soudé 19 de commande de verrouillage ;
• à l'extrémité de cette partie arrière 18, un trou recevant un axe transversal 20, pour la liaison du crochet 15 ou 16 avec une élingue de manutention (décrite plus loin).

Each gripping hook 15 or 16, extending substantially rectilinearly and obliquely, on either side of its hinge axis 10, comprises itself:

• a front part, located under the spreader 4, and forming a hooking nose 17 directed inwards;
• a rear portion 18, located above the spreader 4, and acting as a counterweight;
• in the rear portion 18, a welded lock control finger 19;
• at the end of this rear portion 18, a hole receiving a transverse axis 20, for the connection of the hook 15 or 16 with a handling sling (described later).

It will be noted that the protection plates 42 extend in the deflection zone of the rear parts 18 of the two gripping hooks 15 and 16, to protect the hands of the operator.

The gripper 2 also includes two pivoting latches, respectively 21 and 22, articulated symmetrically on the horizontal axes 11 carried by the spreader 4, with a first lock 21 associated with one of the gripping hooks 15, and a second latch 22 associated with the other hook of grasping 16.

• une partie inférieure 23 formant contrepoids, dirigée vers l'extrémité correspondante du palonnier 4 ;
• une partie supérieure 24 formant bec de verrouillage ;
• sur la partie supérieure 24, une rampe 25 tournée vers l'avant, destinée à coopérer avec le doigt 19 de commande de verrouillage du crochet 15 ou 16 associé ;
• une tige transversale 26 de commande de déverrouillage.

Each lock 21 or 22 itself has a bent and hook shape, with:

• a counterweight lower portion 23, directed towards the corresponding end of the spreader 4;
• an upper portion 24 forming a locking nose;
• on the upper part 24, a ramp 25 facing forward, intended to cooperate with the locking pin 19 of the associated hook 15 or 16;
• a transverse rod 26 for unlocking control.

Finally, the gripper 2 comprises two metal slings 27 and 28, which are arranged in inverted "V". At their lower extremities, both slings 27 and 28 are provided with respective rings 29, for their connection respectively with the rear ends of the two hooks of 15 and 16, each ring 29 being traversed by the axis 20 of the hook associated. The respective upper ends of the two slings 27 and 28 are connected to a common ring 30, for the handling of the whole of the gripper 2. Note that each sling 27 or 28 forms, with the axis longitudinal of the gripping hook 15 or 16 corresponding, an obtuse angle less than 180 °, to ensure a holding force in position locked hooks 15 and 16, when the gripper 2 is raised.

In addition, the weighting device comprises an arrangement particular ballast blocks 3, adapted to the gripper 2 previously described.

Each ballast block 3, made essentially of concrete, has an elongated parallelepipedal general shape, and it comprises two inserts metal 31 and 32 embedded in the concrete during casting. As indicated in particular Figure 2, the two metal inserts 31 and 32 are arranged symmetrically on the ballast block 3, and each insert 31 or 32 is composed a gripping portion 33 of the ballast block, and a centering portion 34 blocks between them.

The gripping portion 33 is like a chimney flattened, extending over the entire height of the ballast block 3, and crossing, in its upper part, by a transverse axis 35. The spacing between the two axes 35, respectively belonging to the two inserts 31 and 32, corresponds to the horizontal distance between the respective hooks 17 two gripping hooks 15 and 16 of the gripper 2.

The centering portion 34 extends vertically on the outer side of the gripping portion 33, to which it is attached by bars horizontal 36. In the general shape of a rod, this centering portion 34 has, at its apex, a conical centering pin 37 preferably removable, protruding above the upper face of the ballast block 3. At its base, the centering portion 34 forms a housing 38 of conical shape or pyramidal, which opens into the lower face of the ballast block 3 and is provided to receive a centering pin of a lower ballast block.

As shown in Figures 2, 7, 9 and 12, the two inserts 31 and 32 have a difference of shape, as far as their respective dwellings. The centering portion 34 located to the right on the drawing has the general shape of a pyramid with a substantially square base. The other centering portion 34, located on the left, which is also shown on the Figure 13, has the general shape of a rectangular pyramid elongated in the longitudinal direction of the ballast block 3.

The use of the weighting device, for laying blocks of ballast 3, will now be described, with reference to the successive figures of drawing. This use includes, in general, the attachment of the blocks of ballast 3, then their handling, and finally their stall.

Referring first to Figures 2 and 3, the hooking is performed by bringing, over a block of ballast 3, the gripper 2 itself which is suspended, by the upper ring 30, to a handling hook (no represent). Initially, the two grip hooks 15 and 16 of the gripper 2 are locked, that is to say retained by means of locks respective 21 and 22 in their position for which the two beaks latching 17 are raised, and spaced at most from one another. The locked position of the gripping hooks is particularly illustrated, for the hook 16, by the figure 3 which shows how this hook 16 is retained, by its finger 19, in the lock 22.

The gripper 2 is lowered towards the ballast block 3, and centered on this block 3 using the two centering brackets 8 and 9 which are placed at the edge of the housing delimited by the respective gripping portions 33 of the two metal inserts 31 and 32 - see Figure 4.

The operator then manually unlocks the two hooks of 15 and 16, by acting on the control rod 26 of each 21 and 22, so as to release the fingers 19 of the hooks 15 and 16. FIG. 5 illustrates this unlocking operation, the movement of manual pivoting latch 22 here visible being indicated by the F1 arrow.

Then, we start the lifting of the whole; the slings 27 and 28 are stretched, and the gripping hooks 15 and 16 pivot according to the arrow F2, in the direction of lowering and tightening their beaks 17. These latches 17 then engage around transverse axes 35 of the grip portions 33 of the ballast block 3. On refers here more particularly to Figure 6, which represents the detail B enlarged of Figure 7.

The ballast block 3 is thus supported by the gripper 2, in a lifting position illustrated in Figure 7. When lifting the ballast block 3, the holding in position of the two gripping hooks 15 and 16 is ensured by the mere weight of this block 3, given the angle less than 180 ° formed by each sling 27 or 28 with the longitudinal axis of the hook 15 or 16 corresponding.

We then operate the handling of the ballast block 3 raised, for bring it above the similar ballast blocks 3 previously placed and stacked on the base frame 39 of the crane, over which the mast 40 of the crane - see figure 8. During this operation, the guide ballast block 3 raised and moved is provided by the operator 41 posted on the ground, by means of a rope 14 attached to the rudder 4, plus particularly to a terminal ring 13 of this spreader 4.

The ballast block 3 is thus presented above the ballast blocks 3 previously stacked, as shown in Figure 9, the positioning correct of this block of ballast 3 on the other blocks, being ensured by the parties of centering 34. More specifically, tapered centering pins 37 belonging to the ballast block 3 previously installed come to cooperate with the housings 38 of conical or pyramidal shape of the ballast block 3 currently being pose (Figure 9 showing these elements just before they cooperate). then of this operation, the housing 38 of particular pyramidal shape, based on elongated rectangular, allows to absorb positioning differences between the two blocks of ballast 3, while guaranteeing the correct alignment of the faces side of these two blocks 3.

The ballast block 3 considered is thus "self-centered" on block 3 immediately inferior, on the upper face of which it finally comes take support.

From this moment, the stall of the block of ballast 3 which has just been laid, this last phase being illustrated by Figures 10 to 12. For this purpose, the movement of descent of the hook is continued. handling, so that the slings 27 and 28 relax.

Under the effect of the counterweight constituted by their rear parts 18 respective grip hooks 15 and 16 initiate a movement of tilting, around the pivot axes 10, as indicated by the arrow F3 (for hook 16) in Figure 10.

The descent movement of the handling hook is pursuing, the beaks 17 of the gripping hooks 15 and 16 release finally the transverse axes 35 of the ballast block 3, as illustrated by Figure 11 which shows the enlarged detail C of Figure 12.

During the tilting of the gripping hooks 15 and 16 which occurs during the descent of the handling hook, the finger 19 of each of these hooks acts on the ramp 25 of the associated lock 21 or 22. The tilting of the latches 21 and 22, which takes place by gravity when the finger 19 arrives at the lower end of the ramp 25, causes the lock automatic two gripping hooks 15 and 16 by the locks respective 21 and 22.

The gripper 2 can then be removed from the ballast block 3 that comes to be placed, and this gripper 2 can be reused, as described above, for taking and laying the next ballast block 3, and so on ...

It will be noted that the ballast blocks 3 can thus be stacked either in direct overlay (see Figures 9 and 12), either staggered as illustrated by figure 8.

One would not depart from the scope of the invention, as defined in the appended claims, by constructive modifications of the rake, or by modifications of the detail of the shape of the hooks of prehension and their locks, or by adapting to blocks of ballast of all sizes and shapes.

Claims (12)

Crane weighting device, in particular for tower cranes, combining ballast blocks (3) stackable on a base frame (39) of the crane, and a gripper (2) for the handling of ballast blocks (3) , the gripper (2) being intended to be connected, in use, to a handling means this device comprising non-permanent connection means by hooking between the gripper (2) and a block of ballast (3), and means for centering ballast blocks (3) stacked with respect to one another, characterized in that said non-permanent connection means comprise two opposite gripping hooks (15, 16) pivotally mounted about horizontal axes ( 10), in the end regions of a lifter (4) of the gripper (2), each gripping hook (15, 16) having, on one side of its pivot axis (10), a beak of hooking (17) designed to cooperate with a transverse axis (35) placed in a corresponding housing (33) a ballast block (3), and on the other side of its pivot axis (10), a rear portion (18) attached to a sling (27, 28) by which the gripper (2) is suspended from the lifting cable, with each gripping hook (15, 16) being associated a latch (21, 22) carried by the spreader (4) and provided to temporarily hold the corresponding gripping hook (15, 16) in position releasing the transverse axis (35). Crane ballast device according to claim 1, characterized in that the spreader bar (4) consists of two parallel bars or sections (5, 6) which are secured to each other by means of a longitudinal interstice between them (7), so as to form at both ends of the spreader (4) of the yokes for the articulation of the two suspension hooks (15, 16). Crane ballast device according to claim 2, characterized in that on the two bars or profiles (5, 6) of the crossbar (4) are fixed vertical protection plates, which protect the deflection area of the rear part (18). ) gripping hooks (15, 16). Crane ballast device according to any one of claims 1 to 3, characterized in that the rear portion (18) of each gripping hook (15, 16) itself constitutes, or carries, a counterweight. Crane weighting device according to one of Claims 1 to 4, characterized in that each sling (27, 28) forms, with the longitudinal axis of the corresponding gripping hook (15, 16), an angle of less than 180 °. Crane ballast device according to any one of claims 1 to 5, characterized in that each latch (21, 22) of the gripper (2) is a latch pivoted about a horizontal axis (11) carried by the rudder , the latch (21, 22) having a bent shape, with a lower part (23) forming a counterweight, and an upper part (24) forming a locking nose and provided with a ramp (24) intended to cooperate with a finger control (19) carried by the rear portion of the gripping hook (15, 16) corresponding. Crane ballast device according to one of Claims 1 to 6, characterized in that the ballast blocks (3), essentially made of concrete, each comprise two metal gripping parts (33), embedded in the concrete, which each delimits a housing adapted to receive partially a gripping hook (15, 16), each metal gripping portion (33) being provided with a transverse axis (35), passing through the housing which it delimits and intended to cooperate with the latching nose (17) of a gripping hook (15, 16) engaged in this housing. Crane weighting device according to claim 7, characterized in that two positioning brackets (8, 9) are provided below the lifting beam (4) for cooperating respectively with the upper edges of the housing defined by the two gripping portions (33) of a ballast block (3). Crane ballast device according to one of Claims 1 to 8, characterized in that the means for centering the ballast blocks (3) stacked with each other on each ballast block (3). conical centering pins (37), protruding above the upper face of the ballast block (3), and corresponding recesses (38) of flared shape, in particular conical or pyramidal shape, which open into the underside of the ballast block (3). Crane ballast device according to claim 9, characterized in that one of the flared housing (38) of each ballast block (3) has the general shape of an elongated rectangular base pyramid in the longitudinal direction of this block of ballast (3). Crane ballast according to Claims 2 and 9, characterized in that the centering pegs (37) and corresponding recesses (38) belong to metal centering parts (34), each metal centering part ( 34) extending vertically on one side of a metal gripping portion (33), and being attached thereto (at 36) to form a single metal insert (31, 32) embedded in the concrete of the block of ballast (3). Crane ballast device according to one of Claims 1 to 11, characterized in that the lifting beam (4) is provided at its ends with rings (12, 13) for receiving a guide rope (14). , usable during the handling of a ballast block (3), hooked under the spreader (4).

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