EP0451061B1 - Remote-controlled motorized load engaging device - Google Patents

Abstract

The device comprises a gripper (15) whose arms (16, 17) hold at their free end an on-loading mechanism (18, 19) designed to engage a load (13) by gripping accessories (14). Two connecting rods (21, 22) constitute a deformable diamond with the upper part of the gripper (15). The lower ends of connecting rods (21, 22) are hinged to a shoulder (27) of a guide column (28) on which moves a slide (29) forming the head of the gripper (15). Two jacks (45, 46) control the opening and closing of the gripper (15). A connector arm (30) links the shoulder of column (28) to a turning grappling rope (10) and allows the center of gravity to be corrected by a jack (52). This gripping device is intended for use with raising devices such as turret slewing cranes.

Description

The present invention relates to the field of load handling, in particular on building sites and public works. It relates to a motorized device for gripping heavy and bulky loads, such as formwork, prefabricated panels and slabs, the device being remotely controlled for its functions of gripping and setting loads. This device is intended more particularly for cable lifting devices, such as tower cranes and mobile cranes.

It is well known, for these lifting devices, to use hooks, grapples, claws and lifting clamps as a gripping device.

In the most common embodiments, the orientation and centering of the gripping device are carried out manually, while the gripping of the load is carried out by slinging, or automatically, by clamping, when the tensioning cable lifting. Despite the protective devices and safety measures provided, this type of operation always presents a bodily risk to the operator, whether by putting his hands on the moving parts, or simply by virtue of his presence, near the load being handled.

For particular applications, there are automatic gripping devices, also ensuring centering on the load to be grabbed, but this possibility remains reduced. This is the case, for example, in the embodiment described in French Patent No. 2,511,993, where the clamp is equipped with two movable stops facilitating its positioning, relative to the rails to be handled. This is also the case in the embodiment described in French patent No. 2 210 563, where the gripping device comprises a bell, arranged to be hooked to a lifting device, the lower part of which has a mouth in the form of funnel overturned, guided by a tip secured to the load to be handled.

In these two embodiments, the centering requires a fairly precise prior positioning, and the final positioning is not adjustable; thus, these two gripping devices are not adaptable to the various loads to be handled on building sites and public works, which offer very different dimensions and sections from each other and which, because of their intrinsic resistance, must be equipped with at least two gripping accessories, the spacing of which can vary from 0.5 to 2.5 m. When handling these loads, the center of gravity of the load must also be positioned.

By the published French patent application FR-A-2619800, which serves as a basis for the preamble of claim 1, there is known a handling spreader for cylindrical containers, comprising an articulated structure of vertical axis of symmetry, the device comprising a substantially vertical guide column, on which a slide moves forming one of the vertices of the articulated structure. This comprises three pivoting arms or branches which carry, at their free lower end, a support mechanism, while three connecting rods are articulated respectively between the arms or branches and the slide. The lifter can thus be opened or closed like an umbrella. However, the arms or branches being articulated at the upper part of the lifter, on fixed plates, their lower ends provided with the load taking mechanism do not describe a horizontal movement when they approach a load to be grasped. In addition, this lifting beam with three arms or branches, offset by 120 °, can only be used for handling cylindrical loads. Finally, such a spreader does not include any means for positioning and correcting the center of gravity.

The present invention makes it possible to resolve these difficulties, by providing a remote-controlled motorized load gripping device, intended more particularly for cable lifting devices, the general design of which automatically performs the functions of centering, gripping and locking, on any type of load with standardized gripping accessories and spacing, as well as the center of gravity positioning function.

Advantageously, the device according to the invention is designed to be associated with a motorized load rotation device, self-supplied with energy, such as that defined in patent application EP-A-0 409 748, in the name of the Applicant .

• les branches de la structure déformable, au nombre de deux, forment un compas dont la tête est constituée par le coulisseau déplaçable sur la colonne de guidage,
• les bielles, au nombre de deux, sont articulées à l'embase de la colonne de guidage, l'ensemble des deux bielles formant, avec la partie supérieure du compas, un losange déformable,
• un bras de liaison relie l'embase de la colonne de guidage à une suspente montée tournante sous une moufle de l'appareil de levage à câble, autour d'un axe vertical, la moufle étant pourvue d'une motorisation pour l'actionnement en rotation de ladite suspente,
• des liaisons motorisées indépendantes sont prévues, pour la commande d'ouverture et de fermeture du compas, de positionnement par pivotement du bras de liaison, de centrage et de verrouillage des mécanismes de prise de charge, et
• des moyens d'alimentation en énergie et de contrôle / commande, notamment pour les liaisons motorisées, sont aussi prévus.

The device according to the invention is of the type with an articulated structure of vertical axis of symmetry forming a deformable quadrilateral, the device comprising a guide column, substantially vertical, on which a slide moves forming one of the vertices of the articulated structure , this one comprising branches which carry, at their free end, a load taking mechanism, and a set of connecting rods articulated on the branches, and this device being characterized in that:

• the branches of the deformable structure, two in number, form a compass whose head is constituted by the slide movable on the guide column,
• the connecting rods, two in number, are articulated at the base of the guide column, the assembly of the two connecting rods forming, with the upper part of the compass, a deformable diamond,
• a connecting arm connects the base of the guide column to a hanger mounted to rotate under a muffle of the cable lifting device, around a vertical axis, the muffle being provided with a motorization for actuation in rotation of said hanger,
• independent motorized links are provided, for controlling the opening and closing of the compass, positioning by pivoting of the link arm, centering and locking of the load taking mechanisms, and
• power supply and control / command means, in particular for motorized links, are also provided.

According to the principle of the invention, the device is thus suitable for the automatic handling of loads equipped with standardized gripping accessories. In the initial state, the gripping device is entirely folded back on itself, and offers a minimum horizontal size, which allows it to access, in the best possible conditions, at the various points site intervention.

In one embodiment of the invention, the two arms of the compass are each made up of a main beam of “V” shaped section, open towards the inside of said compass, and of a tie rod arranged inside the "V" section of the main beam, each of the branches forming a deformable parallelogram, the four vertices of which are represented by the articulations of the main beam and of the tie rod on the slide, and the articulations of these same elements on the support of the load taking mechanism. Preferably, the connecting rods are articulated in the middle of the main beams of the arms of the compass.

The gripping device according to the invention thus has a. articulated structure light and not very thick, however rigid, and ensuring a good protection of the most fragile organs. In particular, the main beams of "V" section protect the motorized opening and closing members of the compass, produced for example in the form of two identical double-acting cylinders, arranged symmetrically on either side of the guide column and connecting, by articulations, the lower part of the slide to the branches of said compass. The deformable diamond structure, and the length chosen for the arms of the compass, equal to twice the side of the diamond, ensure the rigorous horizontality of the displacement of the free ends of these arms, therefore of the load-taking mechanisms.

According to another characteristic of the invention, the guide column comprises, at its upper part, a substantially horizontal console, serving as a recovery support for a double-acting cylinder, the body of which is articulated in its middle on the upper part of the link arm, and the rod of which is articulated, at its end, to said console.

This arrangement ensures the positioning and correction of the center of gravity, as an additional motorized function of the device.

The link arm can be made up of two parallel beams arranged symmetrically on either side of the planar articulated structure, the two beams being articulated on the base of the guide column and on the rotating hanger, and being connected between them by at least one spacer, arranged above the articulated connection with the body of the jack.

According to one embodiment of the invention, the mechanisms of load take-up consist of supports whose upper part takes up the articulations of the arms of the compass, while their base forms a casing which takes up the guiding, gripping and locking members of the load on the gripping accessories.

The guide members advantageously form two lateral branches of the casing, each consisting of a bore in which a partially fluted shaft spins, at the outlet of which is fixed a bent rod serving as support for a guide ramp for the gripping accessories of the load, said splined shaft meshing with a rack piston which moves axially in a cylinder, and the stroke of which is determined to rotate the rod, from an internal horizontal position corresponding to a gripping of the load by closing the compass, until to an external horizontal position corresponding to a gripping of the load by opening the compass, passing through an intermediate vertical position for storage or rest, preferably indexed by an imprint of the grooved shaft, in which is likely to be engaged , partially, a ball pushed by a spring. A universal use gripping device is thus produced, which not only makes it possible to grip loads equipped with gripping accessories whose spacing can vary, for example, between 0.5 and 2.5 m, but also allows a entry of charges according to two modes, either from the inside or from the outside, the choice of entry mode being made in particular according to the environment. In addition, the rest or storage position of the guide rods provided with ramps, protects these fairly vulnerable members when they do not intervene, and also makes it possible to limit the size of the device.

According to an additional arrangement, the load gripping and locking members form the central part of the casing, consisting of a bore in which a partially grooved shaft journals, at the ends of which are fixed two pyramid-shaped locks, capable of cooperating with openings of the accessories for gripping the load, said splined shaft meshing with a rack piston, which moves axially in a cylinder and the stroke of which is determined to rotate the latches by 90 °, from an unlocked position, to a locked position, identified respectively by two detectors, for example magnetic, arranged at 90 ° from one another, around the periphery of the bore, and cooperating with a blind hole drilled in the body of the shaft grooved.

• Figure 1 montre une grue à tour à flèche distributrice, équipée d'un dispositif de préhension, selon l'invention ;
• Figure 2 est une vue d'ensemble, en perspective, du dispositif de préhension ;
• Figure 3 est une vue latérale d'ensemble du même dispositif de préhension ;
• Figure 4 est une vue détaillée du mécanisme de prise de charge de ce dispositif ;
• Figure 5 est une vue en coupe, suivant V-V de la figure 4 ;
• Figure 6 est une vue en coupe, suivant VI-VI de la figure 4 ;
• Figure 7 est une vue en coupe partielle, suivant VII-VII de la figure 6 ;
• Figures 8 et 9 montrent, en coupe, le système de verrouillage en position non verrouillée ;
• Figures 10 et 11 montrent, en coupe, le système de verrouillage en position verrouillée ;
• Figures 12 à 18 représentent, de façon schématique, différentes phases de fonctionnement du dispositif de préhension.

In any case, the invention will be better understood, with the aid of the description which follows, with reference to the appended diagrammatic drawing representing, by way of nonlimiting example, an embodiment of this motorized load gripping device remote control:

• Figure 1 shows a tower crane with distribution jib, equipped with a gripping device, according to the invention;
• Figure 2 is an overall perspective view of the gripping device;
• Figure 3 is an overall side view of the same gripping device;
• Figure 4 is a detailed view of the charging mechanism of this device;
• Figure 5 is a sectional view along VV of Figure 4;
• Figure 6 is a sectional view along VI-VI of Figure 4;
• Figure 7 is a partial sectional view along VII-VII of Figure 6;
• Figures 8 and 9 show, in section, the locking system in the unlocked position;
• Figures 10 and 11 show, in section, the locking system in the locked position;
• Figures 12 to 18 show, schematically, different phases of operation of the gripping device.

As shown in Figure 1, the gripping device, object of the invention, generally designated by the reference 1, is intended to equip lifting devices, such as a tower crane 2 with distribution boom 3. The gripping device 1 is suspended from the jib 3 of the crane 2, by means of a lifting cable 4 forming a hauling system 5, between a distribution carriage 6 and a muffle 7. At one end, the lifting cable 4 is fixed at a point 8, at the head of arrow 3; at the other end, the cable 4 is wound on the drum of a winch 9, placed at the foot of the arrow 3. The muffle 7 comprises a hanger 10, rotatably mounted around a vertical axis 11, and a motorization , for driving the hanger 10 in rotation around the vertical axis 11, as indicated by an arrow "F".

The gripping device 1 is suspended on the hanger 10, by means of a horizontal axis 12, and is equipped with the means necessary for ensuring automatic handling of a load 13 fitted with standardized gripping accessories 14.

With particular reference to Figures 2 and 3, the gripping device 1 is in the form of a planar articulated structure, situated in a substantially vertical plane and consisting of a compass 15, the two branches 16, 17 of which bear , at their respective lower ends, load-taking mechanisms 18, 19, and a set 20 of two connecting rods 21, 22, the first end of which is articulated at 23, 24 on the central part of the branches 16, 17 of the compass 15, while the other end is articulated at 25, 26 to the base 27 of a column 28, substantially vertical, along which a slide 29 moves in translation, forming the head of the compass 15.

The gripping device 1 also comprises a double link arm 30, connecting the base 27 of the column 28 to the hanger 10 of the muffle 7.

The branches 16, 17 of the compass 15 each consist of a main beam 31, 32, of section in the shape of a "V", open towards the interior of said compass 15, and of a tie rod 33, 34 disposed at the interior of the "V" of the main beam 31, 32; each of the branches 16, 17, forms a deformable parallelogram whose four vertices are represented by the articulations 35, 36, 37, 38 of the main beams 31, 32, and tie rods 33, 34 on the slide 29, and the articulations 39, 40, 41, 42 of these same elements 31, 32, 33, 34 on a support 43, 44, of the load taking mechanism 18, 19.

According to an additional characteristic, the compass 15 and the assembly 20 of the two connecting rods 21, 22 form a deformable diamond so that in operation, the load-taking mechanisms 18, 19 move in a substantially horizontal plane, containing the joints 25, 26 and 39 to 42. The opening or closing of the compass 15 is ensured by two identical double-acting hydraulic cylinders 45, 46, arranged symmetrically on either side of the column 28, connecting by joints 47 , 48 on the one hand, and 49, 50 on the other hand, the lower part of the slider 29 with the respective main beams 31, 32 of the arms 16, 17 of said compass 15.

At the upper end of the column 28 for guiding the slide 29, is fixed a console 51, substantially horizontal, disposed in the plane of the articulated structure, and serving for the recovery of a hydraulic cylinder with double effect 52, the body 53 of which is connected in its middle by a hinge 54 to the upper part of the double link arm 30, and the rod 55 of which is articulated at 56 at the free end of the console 51.

The double-acting cylinder 52 provides an angular movement of the link arm 30, about its articulation axis 57, on the base 27 of the column 28 for guiding the slide 29. This link arm 30 consists of two side members parallel 58, arranged symmetrically on either side of the planar articulated structure of the gripping device 1, and rigidly connected, between the jack 52 and their articulation 12 on the hanger 10 of the block 7, by means of spacers 59.

As shown in detail in FIGS. 4 to 6, each load taking mechanism 18 or 19 consists of the support 43, the upper part of which takes up the joints 39, 41 of the branch 16 or 17 of the compass 15, while the base of this support forms a casing 60, which takes up the guiding, gripping and locking members of the load 13 on the gripping accessories 14.

The guide members form two lateral branches 61, 62 of the casing 60, while the gripping and locking members form the central part 63 of said casing 60.

The lateral branch 61 or 62 of the casing 60, consists of a bore 64, with an axis inclined to the horizontal, in which a partially grooved shaft 65 is journalled, at the outlet of which is fixed a bent rod 66, serving as a support to a guide ramp 67, for the gripping accessories 14. FIG. 7 shows the detail of the pivoting control of the rod 66; the splined shaft 65 meshes with a rack piston 68, moving axially in a cylinder 69, and the stroke of the piston 68 is determined to pivot the guide rod 66, from an inner extreme horizontal position, corresponding to a gripping of the load 13 by closing the compass 15, to an extreme external horizontal position, corresponding to a gripping of the load 13 by opening the compass 15, passing through an intermediate vertical position of rest, shown in FIG. 6. As the also shows this figure 6, the two guide members 61, 62, are offset in height, one relative to the other, so that their guide rods 66, 67 can slide one under the other, c that is to say that those of the load taking mechanism 18 slide on those of the other load taking mechanism 19, when the gripping accessories 14 of the load 13 are separated by a short distance.

According to an additional characteristic, the splined shaft 65 has an imprint 70, in which is capable of engaging a ball 71, pressed by a spring 72, to maintain the guide rod 66 in the vertical rest position.

The central part 63 of the casing 60 consists of a bore 73, in which a partially grooved shaft 74 journals, at the ends of which are fixed two latches 75, 76, of pyramidal shape, capable of cooperating with openings of the gripping accessories 14 of the load 13. The latches 74, 75 are controlled by a rack piston 77, meshing with the splined shaft 74, and moving axially in a cylinder 78. The stroke of the piston 77 is determined to pivot the latches 75, 76 by 90 °, from an unlocked position shown in Figures 8 and 9, to a locked position shown in Figures 10 and 11. Magnetic detectors 79, 80, arranged 90 ° from each other on the bore 73, make it possible to detect the locking and unlocking positions, when these magnetic detectors 79, 80 are located opposite a blind hole 81, drilled on the body of the shaft 74.

By way of example, FIGS. 12 to 18 show different phases of operation of the gripping device according to the invention, for the automatic handling of a load 13 equipped with standardized gripping accessories 14.

As shown in FIG. 12, in the initial state, the gripping device 1 is entirely folded back on itself and thus offers a minimum horizontal size which allows it to access, in the best possible conditions, at the various points of site intervention. In this configuration, the lifting device, such as the tower crane 2 of FIG. 1, ensures the empty handling of the gripping device 1, installed at the rotary hanger 10 of the muffle 7, from which it receives its energy. and its control commands, the gripping device 1 using electro-hydraulic energy.

When the gripping device 1 arrives above the load 13, it is oriented approximately by the crane operator, as a function of the position of the gripping accessories 14, by controlling the rotation of the rotary hanger 10 of the muffle 7, and deployed by the control of the jacks 45, 46 for opening the compass 15.

When the opening of the gripping device 1 is sufficient, the crane operator controls the movement of the rack pistons 68 to rotate the guide rods 66 from the vertical rest position to the interior horizontal position, as shown in FIG. 13.

Thanks to a sensor 82, optical or other, placed under the base 27 of the guide column 28, the gripping plane is detected during the final slow descent of the gripping device 1 by the presence, in this plane, gripping accessories 14, advantageously provided with receiving means for their identification.

With the height adjustment made, the crane operator controls the closing of the compass 15, as shown in FIG. 14.

During this phase, the guide rods 66 and the ramps 67 automatically center the gripping device 1 on the load 13. At the end of the race, the centering is ensured by sheets 83 of the casing 60 itself.

When the centering device comes to a stop, the crane operator controls the movement of the pistons 77, in order to pivot the latches 75, 76 then introduced through the openings of the gripping accessories 14, and thus lock the load 13. In this position, the guide rods 66 are returned to the vertical position, as shown in FIG. 15. In addition, the crane operator ensures the search for the center of gravity of the load 13, by controlling the pivoting of the double link arm 30, via the cylinder 52, the control being able to be carried out by an inclinometer not shown (see FIG. 16). The load 13 being well balanced, the crane operator then proceeds to handle this load 13, and to place it at the desired destination. Finally, the crane operator proceeds to refocus the gripping device 1, and to detach the load 13, by carrying out the reverse maneuvers to those defined above.

Figures 17 and 18 illustrate the possibility of entering from the inside, and no longer from the outside, of a load 13 equipped with the same standardized gripping accessories 14. The entry from the inside is carried out by opening the compass 15, while this compass is closed when entering from the outside.

A motorized device for gripping loads with remote control is thus produced, which automatically performs the functions of centering, gripping and locking, on any type of load 13 having gripping accessories 14, of standardized shape and spacing, as well as the center of gravity positioning function. In addition, the device 1 allows the taking of loads 13 having an inclination on the horizontal, due to a bad leveling of the ground or a slope of the storage area, the adaptation to the possible inclination d 'A load being obtained by acting on the actuator 52 which controls the pivoting of the link arm 30. It may also be noted that this gripping device 1 can be used as a lifting beam, by providing attachment points for handling slings.

Claims (11)

1. Remote-controlled motorised load-gripping device, intended for cable lifting appliances and comprising an articulated structure with a vertical axis of symmetry forming a deformable quadrilateral, the device comprising a substantially vertical guide column (28) on which moves a slide (29) forming one of the apices of the articulated structure, the latter having legs (16, 17) which carry, at their free end, a load-bearing mechanism (18, 19), and a set (20) of links (21, 22) pivoted on the legs (16, 17), characterised in that:

   - the legs (16, 17) of the deformable structure, two in number, form a calliper (15), the head of which is formed by the slide (29) movable on the guide column (28),

   - the links (21, 22), two in number, are pivoted (at 25, 26) on the base (27) of the guide column (28), the set (20) of two links (21, 22) forming, with the top part of the calliper (15), a deformable diamond,

   - a connecting arm (30) connects the base (27) of the guide column (28) to a grappling rope (10) mounted under a pulley block (7) of the cable lifting appliance so as to rotate about a vertical axis (11), the pulley block (7) having motorisation for rotating the said grappling rope (10),

   - independent motorised connections (45, 46, 52, 65, 68, 74, 77) are provided for controlling the opening and closing of the calliper (15), for positioning the connecting arm (30) by pivoting, and for centring and locking the load-bearing mechanisms (18, 19), and

   - means for power supply and control/actuation (82), notably for the motorised connections, are also provided.
2. Motorised load-gripping device according to Claim 1, characterised in that the two legs (16, 17) of the calliper (15) each consist of a main beam (31, 32) with a cross section in the shape of a "V" open towards the inside of the said calliper (15), and a tie rod (33, 34) disposed inside the V-shaped cross section of the main beam (31, 32), each of the legs (16, 17) forming a deformable parallelogram, the four angles of which are represented by the articulations (35, 36, 37, 38) of the main beam (31, 32) and tie rod (33, 34) on the slide (29) and the articulations (39, 40, 41, 42) of these same members (31, 32, 33, 34) on the support (43, 44) of the load-bearing mechanism (18, 19).
3. Motorised load-gripping device according to Claim 2, characterised in that the links (21, 22) are pivoted at the middle (23, 24) of the main beams (31, 32) of the legs (16, 17) of the calliper (15).
4. Motorised load-gripping device according to any one of Claims 1 to 3, characterised in that the motorisation mechanisms for opening and closing the calliper (15) are produced in the form of two identical double-acting rams (45, 46) disposed symmetrically on each side of the guide column (28) and connecting, by means of articulations (47, 48, 49, 50), the bottom part of the slide (29) to the legs (16, 17) of the said calliper (15).
5. Motorised load-gripping device according to any one of Claims 1 to 4, characterised in that the guide column (28) has, at its top, a substantially horizontal bracket (51) serving as a support for a double-acting rams (52), the cylinder (53) of which is pivoted at its middle (54) on the top part of the connecting arm (30) and the piston rod (55) of which is pivoted at its end (56) on the said bracket (51).
6. Motorised load-gripping device according to Claim 5, characterised in that the connecting arm (30) consists of two parallel longitudinal members (58), disposed symmetrically on each side of the flat articulated structure, the two longitudinal members (58) being pivoted (at 57) on the base (27) of the guide column (28) and (at 12) on the rotating grappling rope (10), and being connected together by at least one brace (59) disposed above the pivoted connection (54) with the cylinder (53) of the ram (52).
7. Motorised load-gripping device according to any one of Claims 1 to 6, characterised in that the load-bearing mechanisms (18, 19) consist of supports (43, 44), the top part of which carries the pivots (39, 40, 41, 42) of the legs (16, 17) of the calliper (15), whilst their base forms a housing (60) which carries the mechanisms (61 to 81) for guiding, gripping and locking the load (13) on the gripping accessories (14).
8. Motorised load-gripping device according to Claim 7, characterised in that the guide mechanisms form two lateral arms (61, 62) of the housing (60), each consisting of a bore (64) in which a partially fluted shaft (65) turns, at the outlet of which is fixed a bent rod (66) serving as a support for a guide ramp (67) for the accessories (14) for gripping the load (13), the said fluted shaft (65) engaging with a piston with a rack (68), which moves axially in a cylinder (69) and the travel of which is determined so as to cause the guide rod (66, 67) to pivot from an inner horizontal position corresponding to a gripping of the load (13) by closure of the calliper (15), to an outer horizontal position corresponding to a gripping of the load by opening of the calliper (15), passing through an intermediate vertical storage or resting position, preferably located by an indentation (70) in the fluted shaft (65), in which a bore (71) pushed by a spring (72) is able to be partially engaged.
9. Motorised load-gripping device according to Claim 8, characterised in that the mechanisms for gripping and locking the load (13) form the central part (63) of the housing (60), consisting of a bore (73) in which rotates a partially fluted shaft (74), at the ends of which are fixed two pyramid-shaped latches (75, 76), able to cooperate with openings in the accessories (14) for gripping the load (13), the said fluted shaft (74) engaging with a piston with a rack (77), which moves axially in a cylinder (78) and the travel of which is determined so as to cause the latches (75, 76) to pivot through 90°, from an unlocked position to a locked position, located respectively by two sensors (magnetic for example) (79, 80), disposed at 90° to each other on the circumference of the bore (73) and cooperating with a blind orifice (81) formed on the body of the fluted shaft (74).
10. Motorised load-gripping device according to Claim 8 or 9, characterised in that the guide mechanisms (61, 62) are offset in height with respect to each other so that their respective guide rods (66, 67) are able to slide one under the other, when the accessories (14) for gripping the load (13) are separated by a small distance.
11. Motorised load-gripping device according to any one of Claims 1 to 10, applied particularly to a crane with a tower (2) with a bogie jib (3), characterised in that the motorised device for rotating the grappling rope (10) about the vertical axis (11) is notably a self-powering motorised device and in that the gripping device (1) receives, from the rotating grappling rope (10), its power and its commands.

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