EP3415458A1 - Device and method for automatic tensioning of a dispensing cable for a crane - Google Patents

Abstract

Automated tensioning device (1) for a distributor cable (4) for moving a distributor carriage (3) along a crane boom, comprising a motor cooperating with the cable for moving the carriage, a mechanism tensioner for adjusting the tension of the cable, and an automated control system comprising:
- A stop (7) movable between a rest position and several working positions in the presence of a thrust force exerted by the carriage;
- A return member (8) urging said stop towards its rest position and providing a force resistant to thrust exerted by the carriage; and
- a proximity sensor (9) detecting the stop in its rest position and its working positions;
- A control unit connected to the motor and the sensor to control a tension of the cable according to a stroke of the stop between its rest position and its working positions.

Description

The present invention relates to automated tensioning device of a distributor cable ensuring the displacement of a distributor carriage movable along a ditributrice arrow of a crane.

It also relates to a hoisting crane, such as a tower crane, comprising such a tensioning device, as well as to a method of automated tensioning of a distributor cable in such a crane.

In the field of cranes, it is known from the previous document FR 2,456,700 to use a tensioning device comprising a motor cooperating with the distributor cable to ensure the displacement of the distributor carriage, by means of a distribution winch coupled to the motor and comprising a winding drum on which are fixed ends of a front and rear strand of the cable distributor. It is also known from this document to provide a tensioning mechanism coupled to the distributor cable for adjusting the tension of the dispenser cable, wherein this tensioning mechanism comprises a differential drum device rotatably mounted on the distributor carriage.

The distributor cable generally has a long length, which may exceed 100 meters depending on the boom lengths, which contributes to the distribution cable lengthening during the time of its use, so that it is essential to tighten this distributor cable. regularly. Generally, it is necessary to perform this re-tensioning of the distributor cable about two to three times during the first month of use of the crane, then thereafter once a quarter.

This tensioning of the distributor cable is indeed necessary to ensure proper operation of the translation of the dispenser carriage which does not accept having a relaxed dispenser cable, because the safety device of the slack cable would come into action and block the trolley in safety position in accordance with the usual safety requirements, and in particular with the indications of the European standard EN 14439 on "cranes - safety - tower cranes".

This tensioning of the distributor cable is also necessary to guarantee a reactive operation of the translation of the distributor carriage and a precise positioning of the distributor carriage on the boom. Indeed, with each movement pulse, the distributor carriage reacts faster when the distributor cable is sufficiently tight because there will be little or no slack cable to recover.

In the example of the document FR 2,456,700 this operation consists in rotating the two drums of diameters distinct from the differential drum device, in a first direction of rotation corresponding to a winding of the front strand on the drum of larger diameter, thus contributing to a winding of a larger diameter. front strand length around the larger diameter drum compared to the concomitant rear strand winding around the smaller diameter drum; this winding difference between the two drums contributing to the required tensioning. A ratchet locking system is also provided to prohibit the rotation of the drums in a second opposite direction of rotation.

To rotate the two drums of the differential drum device, it is now planned to do it manually by means of a specific operating key manipulated by an operator placed on the arrow. Such an operating key is usually quite long, for example between 70 and 120 centimeters, so that the operator can exert sufficient effort to tighten the distributor cable. This re-tensioning operation of the distributor cable constitutes a dangerous maneuver to be performed in height on the boom of the crane and adds an additional cost of operating the crane.

The present invention aims to solve all or part of the aforementioned drawbacks, by proposing a tensioning device of a distributor cable that is automated, autonomous and controllable directly by the crane driver, so without the need for manual intervention, thus contributing to improving safety during the operation of the crane and thus reducing maintenance costs, and reducing maintenance downtime and thus increasing on-site productivity and operating costs of the crane .

• une butée montée mobile sur un élément de structure fixe de la grue entre une position de repos en l'absence de poussée exercée par le chariot distributeur sur la butée, et plusieurs positions de travail en présence d'un effort de poussée exercé par le chariot distributeur sur la butée ;
• un organe de rappel élastique sollicitant ladite butée vers sa position de repos et offrant un effort résistant à un effort de poussée exercé par le chariot sur la butée ; et
• un capteur de proximité configuré pour détecter la butée dans sa position de repos et ses positions de travail ;
• une unité de pilotage raccordée au moteur et au capteur de proximité pour piloter ledit moteur, et par conséquent un réglage de la tension du câble distributeur, en fonction d'une course de la butée entre sa position de repos et ses positions de travail.

For this purpose, it proposes an automated tensioning device for a distributor cable ensuring the displacement of a distributor carriage movable along a crane dispensing arrow, said tensioning device comprising a motor cooperating with the distributor cable for moving the dispenser carriage and further comprising a tensioning mechanism coupled to the dispenser cable for adjusting the tension of the dispenser cable, said tensioning device further comprising an automated control system comprising:

• a stop mounted on a fixed structure element of the crane between a rest position in the absence of thrust exerted by the carriage dispenser on the stop, and several working positions in the presence of a thrust force exerted by the distributor carriage on the stop;
• an elastic return member urging said stop towards its rest position and offering a force resistant to a thrust force exerted by the carriage on the stop; and
• a proximity sensor configured to detect the stop in its rest position and its working positions;
• a control unit connected to the motor and to the proximity sensor for controlling said motor, and consequently a regulation of the tension of the distributor cable, as a function of a stroke of the stop between its rest position and its working positions.

Thus, and as described later, such a tensioning device can automatically tension the dispenser cable by moving the dispenser carriage which pushes the stopper, depending on the stroke of the stopper during this thrust. In other words, this tensioning device is automated to facilitate the implementation by the crane operator, ensure the right maneuvers and their accuracy, and allow to have mastered repeatability of the sequences and efforts put in the cable (s) of distribution.

This tensioning device also allows, as described later, to automatically ensure an update of the "zero scope" of the distributor carriage which corresponds to the reference position of the distributor carriage to determine its position along the arrow, after retention.

The elastic return member is calibrated to a predefined stiffness value as a function of the desired tension in the distributor cable; the return member establishing a progressive resistance force, increasing as the return member is pushed under the effect of the thrust of the carriage, to a thrust distance chosen to establish a tension force sufficient in the distributor cable for the proper operation of the dispenser carriage.

According to one characteristic, the stop is slidably mounted in translation on the fixed structure element of the crane.

Alternatively, the stop is pivotally mounted on the fixed structure member of the crane.

According to another feature, the stop has a first end having a stop surface for the distributor carriage, and a second end having a detection surface for the proximity sensor positioned opposite this detection surface.

In a particular embodiment, the detection surface of the abutment is a flat surface inclined relative to a sliding direction in translation of said abutment.

Thus, the distance between the detection surface and the proximity sensor varies as a function of the translational movement of the stop.

In a particular embodiment, the abutment passes through the fixed structural element so that the abutment surface and the detection surface are disposed on either side of the fixed structural element.

Advantageously, the elastic return member is interposed between the fixed structural element and the abutment surface provided at the first end of the abutment.

• un brin avant du câble distributeur présente une première extrémité fixée sur un premier côté du tambour d'enroulement et une seconde extrémité opposée fixée sur le mécanisme tendeur, ce brin avant passant par au moins une poulie de renvoi disposée en pointe de la flèche distributrice ; et
• un brin arrière du câble distributeur présente une première extrémité fixée sur un second côté du tambour d'enroulement et une seconde extrémité opposée fixée sur le mécanisme tendeur, ce brin arrière passant par au moins une poulie de renvoi disposée au pied de la flèche distributrice.

According to a possibility of the invention, the tensioning device comprises at least one distribution winch coupled to the engine and comprising a winding drum, where:

• a front end of the distributor cable has a first end fixed on a first side of the winding drum and an opposite second end fixed to the tensioning mechanism, this front strand passing through at least one deflection pulley arranged in a point of the dispensing boom; and
• a rear end of the distributor cable has a first end attached to a second side of the winding drum and an opposite second end fixed to the tensioning mechanism, the rear end passing through at least one return pulley disposed at the foot of the dispensing boom.

• deux tambours de diamètres distincts et solidaires en rotation, la seconde extrémité du brin avant du câble distributeur étant fixée pour s'enrouler sur un tambour de plus grand diamètre et la seconde extrémité du brin arrière du câble distributeur étant fixée pour s'enrouler sur un tambour de plus petit diamètre, où le brin avant et le brin arrière sont enroulés de sorte que, d'une part, une rotation des deux tambours selon un premier sens de rotation entraîne un déroulement du brin avant sur le tambour de plus grand diamètre et un enroulement du brin arrière sur le tambour de plus petit diamètre et, d'autre part, une rotation des deux tambours selon un second sens de rotation entraîne un enroulement du brin avant sur le tambour de plus grand diamètre et un déroulement du brin arrière sur le tambour de plus petit diamètre ; et
• un système de blocage principal coopérant avec les tambours pour interdire la rotation des tambours selon ledit premier sens de rotation.

According to another possibility of the invention, the tensioning mechanism comprises a differential drum device rotatably mounted on the distributor carriage and comprising:

• two drums of different diameters and fixed in rotation, the second end of the front end of the distributor cable being fixed to wind on a larger diameter drum and the second end of the rear end of the distributor cable being fixed to wind on a drum of smaller diameter, wherein the front and rear strands are wound so that, on the one hand, a rotation of the two drums in a first direction of rotation causes unwinding of the front strand on the drum of larger diameter and a winding of the rear run on the drum of smaller diameter and, on the other hand, a rotation of the two drums in a second direction of rotation causes winding of the front run on the larger diameter drum and unwinding of the rear run on the smaller diameter drum; and
• a main locking system cooperating with the drums to prohibit the rotation of the drums in said first direction of rotation.

This tensioning mechanism with differential drum device is particularly well suited to the invention, without other types of tensioning mechanisms can be envisaged, such as mechanisms with swallowing drum. It should be noted that the first direction of rotation of the drums of the differential drum device results in a loosening (or a decrease) of the tension in the distributor cable. It should be noted that a rotation of the two drums in the second direction of rotation corresponds to a tensioning of the distributor cable, in other words to an increase of the tension in the distributor cable.

• une configuration fermée dans lequel il coopère avec les tambours pour interdire la rotation des tambours également selon le second sens de rotation ; et
• une configuration ouverte dans lequel il autorise la rotation des tambours selon ledit second sens de rotation.

Advantageously, the tensioning mechanism comprises a secondary locking system selectively movable between:

• a closed configuration in which it cooperates with the drums to prohibit the rotation of the drums also in the second direction of rotation; and
• an open configuration in which it allows the rotation of the drums according to said second direction of rotation.

Thus, during the work of distributing the load by the distributor carriage along the dispensing boom, the secondary locking system can be moved in closed configuration so that the two drums of the differential drum device are locked in both directions of rotation. rotation, which has the advantage of avoiding a resumption of balan forces during changes in direction of movement of the distributor carriage. It should be noted that the second direction of rotation of the drums of the differential drum device results in an increase (or an increase) in the tension in the distributor cable.

On the other hand, during the work of adjusting the tension of the distributor cable, the secondary locking system is moved in open configuration and thus the adjustment of the tension is authorized only in a well-defined zone, in particular at the foot of the arrow, and provided that said secondary locking system is in an open configuration.

According to one variant, the secondary locking system is absent, and the rotation of the drums according to the second direction of rotation is constantly allowed.

According to another advantageous characteristic of the invention, the proximity sensor is an inductive sensor or a light sensor.

Advantageously, the stop is movably mounted on a structural element disposed at the foot of the crane dispensing boom, so that the crane driver can have a vision sufficiently close to the distributor carriage during the tension adjustment operation.

The present invention also relates to a hoisting crane comprising a distributing boom along which is movable a trolley, said crane comprising a tensioning device according to the invention, wherein the trolley is movable in a setting configuration in which the trolley distributor exerts a thrust on the stop, against the elastic return member, causing a displacement of the stop to a predefined working position detected by the proximity sensor

• détection de la butée par le capteur de proximité en position de repos, correspondant à un début de course de réglage ;
• premier déplacement du chariot distributeur selon un premier sens de translation jusqu'à venir en appui sur la butée puis exercer une poussée sur la butée, à l'encontre de l'organe de rappel élastique, provoquant un déplacement de la butée jusqu'à une position de travail prédéfinie détectée par le capteur de proximité, correspondant à une fin de course de réglage ;
• mise en tension du câble distributeur par le mécanisme tendeur concomittament au déplacement du chariot distributeur jusqu'à la fin de course de la butée ;
• second déplacement du chariot distributeur selon un second sens de translation, opposé au premier sens de translation, jusqu'au retour de la butée en début de course.

The invention also relates to a method of automated tensioning of a distributor cable in a crane according to the invention, comprising the following steps:

• detection of the stop by the proximity sensor in the rest position, corresponding to a start of the adjustment stroke;
• first displacement of the distributor carriage in a first direction of translation until it bears against the abutment and then exerting a thrust on the abutment, against the elastic return member, causing displacement of the abutment to a stop predefined working position detected by the proximity sensor, corresponding to a limit switch;
• tensioning of the distributor cable by the tensioning mechanism concomitantly with the displacement of the distributor carriage until the end of travel of the stop;
• second displacement of the distributor carriage in a second direction of translation, opposite the first direction of translation, until the return of the stop at the beginning of travel.

Thus, the distributor cable is tensioned automatically, at a voltage dependent on the predetermined stiffness value of the elastic return member, without manual intervention.

It should be noted that the first direction of translation may be a direction of movement towards the rear (in other words towards the foot of arrow) whereas the second direction of translation is a direction of displacement towards the front (in other words in direction of the arrowhead), if the stop / proximity sensor / resilient return member assembly is located at the foot of the arrow.

However, it may be provided that the first direction of translation is a forward direction of travel and that the second direction of translation is a backward direction of movement, if the abutment assembly / proximity sensor / organ of displacement. elastic return is located in arrowhead.

Advantageously, the tensioning method comprises a step of zeroing a reference position of the distributor carriage when the stop is returned to the start of the stroke following the second displacement of the distributor carriage.

Thus, the tensioning method automatically resets the "zero scope" of the distributor carriage which corresponds to the reference position of the distributor carriage to determine its position along the arrow. With the automation of this registration, the risk of error in this reference position is eliminated and the range indication will always remain accurate and reliable.

According to one possibility, the first displacement of the distributor carriage is made from a starting position detected by a presence detector, and this movement is authorized on condition that said presence detector has detected the presence of said distributor carriage in the position of departure.

• au moins une moufle de levage portant un organe de levage et suspendue au chariot ditributeur par un câble de levage est en position haute non descendue ;
• un effort de charge sur l'organe de levage est mesuré comme étant inférieur à 5 % d'une charge maximale prédéfinie.

According to another possibility, the first movement of the distributor carriage is carried out provided that the following conditions are met:

• at least one lifting muffle carrying a lifting member and suspended from the trolley by a hoisting cable is in the up position not descended;
• a loading force on the lifting member is measured as being less than 5% of a predefined maximum load.

According to another possibility, the first movement of the distributor carriage is performed under the action of a manual control exerted by a driver of the crane.

• la figure 1 est une vue schématique en perspective d'une partie de la grue conforme à l'invention ;
• la figure 2 est une vue schématique zoomée de la zone II de la figure 1 qui est positionnée sur l'ensemble butée/capteur de proximité/organe de rappel élastique ;
• la figure 3 est une vue schématique de dessus d'une partie de la grue de la figure 1 ;
• la figure 4 est une vue schématique de côté d'une partie de la grue de la figure 1 ;
• la figure 5 est une vue schématique en perspective de dessous d'une partie de la grue de la figure 1 ;
• la figure 6 est une vue schématique en perspective d'un dispositif à tambour différentiel ;
• la figure 7 est une vue schématique partielle de dessus d'une partie de la grue de la figure 1, illustrant un exemple de réalisation d'un système de blocage secondaire ;
• les figures 8 et 9 sont des vues schématiques de côté du système de blocage secondaire en situation, respectivement dans une configuration fermée (figure 8) et dans une configuration ouverte (figure 9) ;
• la figure 10 est une vue schématique de côté d'une partie de la grue de la figure 1, dans une première configuration où le chariot distributeur est en contact avec la butée lors de son premier déplacement, la butée étant alors en début de course de réglage ;
• la figure 11 une vue zoomée de la zone XI de la figure 10 ;
• la figure 12 une vue schématique équivalente à celle de la figure 10, dans une deuxième configuration (qui fait suite à la première configuration) où le chariot distributeur a terminé son premier déplacement et a poussé la butée jusqu'à une position de travail finale correspondant à une fin de course de réglage ;
• la figure 13 une vue zoomée de la zone XIII de la figure 12 ;
• la figure 14 une vue schématique équivalente à celle de la figure 10 ou 12, dans une troisième configuration (qui fait suite à la deuxième configuration) où le chariot distributeur a effectué son second déplacement jusqu'au retour de la butée en début de course ;
• la figure 15 une vue zoomée de la zone XV de la figure 14 ; et
• les figures 16 et 17 sont des vues schématiques de côté d'une variante de réalisation de la butée, respectivement dans une position de repos en début de course de réglage (figure 16) et dans une position de travail finale en fin de course de réglage (figure 17).

Other features and advantages of the present invention will appear on reading the detailed description below, of an example of non-limiting implementation, with reference to the appended figures in which:

• the figure 1 is a schematic perspective view of a portion of the crane according to the invention;
• the figure 2 is a zoomed schematic view of zone II of the figure 1 which is positioned on the stop / proximity sensor / resilient return member assembly;
• the figure 3 is a schematic view from above of a part of the crane of the figure 1 ;
• the figure 4 is a schematic side view of a part of the crane of the figure 1 ;
• the figure 5 is a schematic perspective view from below of a part of the crane of the figure 1 ;
• the figure 6 is a schematic perspective view of a differential drum device;
• the figure 7 is a partial schematic view from above of a part of the crane of the figure 1 illustrating an exemplary embodiment of a secondary locking system;
• the Figures 8 and 9 are schematic side views of the secondary blocking system in situation, respectively in a closed configuration ( figure 8 ) and in an open configuration ( figure 9 );
• the figure 10 is a schematic side view of a part of the crane of the figure 1 in a first configuration where the distributor carriage is in contact with the stop during its first displacement, the stop being then at the beginning of the adjustment stroke;
• the figure 11 a zoomed view of area XI of the figure 10 ;
• the figure 12 a schematic view equivalent to that of the figure 10 in a second configuration (which follows the first configuration) where the distributor carriage has completed its first displacement and pushed the stop to a final working position corresponding to an adjustment limit switch;
• the figure 13 a zoomed view of area XIII of the figure 12 ;
• the figure 14 a schematic view equivalent to that of the figure 10 or 12 in a third configuration (which follows the second configuration) where the distributor carriage has made its second displacement until the return of the stop at the start of the race;
• the figure 15 a zoomed view of the XV zone of the figure 14 ; and
• the Figures 16 and 17 are schematic side views of an alternative embodiment of the stop, respectively in a rest position at the start of the adjustment stroke ( figure 16 ) and in a final working position at the end of the adjustment stroke ( figure 17 ).

With reference to Figures 1 to 5 a tensioning device 1 according to the invention is provided on a crane 2, of tower crane type, comprising a distributor boom 20 along which is movable a distributor carriage 3, where the boom 20 is mounted on a tower 21 in the foot of the arrow. The distributor carriage 3 is shaped to distribute a load (not shown) along the arrow 2.

The distributor carriage 3 circulates on a raceway between the foot of the boom and the tip of the boom (or free end of the boom), and supports a lifting member 30 (such as a hook) mounted on a muffle of hoist 31 suspended from the trolley trolley 3 by a lifting cable 32.

The trolley 3 is movable forward (that is to say towards the tip of the arrow), and also towards the rear (in other words towards the foot of the arrow).

The tensioning device 1 is provided to allow an automatic adjustment by the crane driver (or crane operator) of the tension of the distributor cable 4 ensuring the displacement of the distributor carriage 3 forwards and backwards.

This tensioning device 1 comprises a motor 5 cooperating with the distributor cable 4 to ensure the displacement of the distributor carriage 3 and further comprising a tensioning mechanism 6 coupled to the distributor cable 4 to ensure adjustment of the tension of the distributor cable 4.

• un grand tambour 61 qui constitue le tambour de plus grand diamètre ; et
• un petit tambour 62 qui constitue le tambour de plus petit diamètre ;

où les deux tambours 61, 62 sont couplés (ou solidaires) en rotation.As visible on the figure 5 , the tensioning mechanism 6 is carried by the distributor carriage 3 and comprises a differential drum device rotatably mounted on the distributor carriage 3 and comprising two drums 61, 62 of different diameters:

• a large drum 61 which constitutes the drum of larger diameter; and
• a small drum 62 which constitutes the drum of smaller diameter;

where the two drums 61, 62 are coupled (or integral) in rotation.

The distributor cable 4 is coupled to a distribution winch mounted at the bottom of the boom and comprising a winding drum 50 rotated by the motor 5 in two opposite directions of rotation, so that the rotation of the motor 5 causes the displacement of the distributor carriage 3 forwards or backwards in the direction of rotation of the winding drum 50.

• un brin avant 41 du câble distributeur 4 présente :
  • une première extrémité 411 fixée pour s'enrouler sur un premier côté du tambour d'enroulement 50 et
  • une seconde extrémité 412 opposée fixée pour s'enrouler sur le grand tambour 61 du mécanisme tendeur 6 ;
  • où ce brin avant 41 passe par une poulie de renvoi (non visible sur les figures) disposée à la pointe de la flèche 20 ; et
• un brin arrière 42 du câble distributeur 4 présente :
  • une première extrémité 421 fixée pour s'enrouler sur un second côté du tambour d'enroulement 50 ; et
  • une seconde extrémité 422 opposée fixée pour s'enrouler sur le petit tambour 62 du mécanisme tendeur 6 ;
  • où ce brin arrière 42 passe par une poulie de renvoi 43 disposée au pied de la flèche 20.

The distributor cable 4 is coupled to both the winding drum 50 of the distribution winch and to the drums 61, 62 of the tensioning mechanism 6 in the following manner, with reference to FIG. figure 10 :

• a front end 41 of the distributor cable 4 has:
  • a first end 411 fixed to wind on a first side of the winding drum 50 and
  • a second end 412 opposite fixed to wind on the large drum 61 of the tensioning mechanism 6;
  • where this front strand 41 passes through a return pulley (not visible in the figures) disposed at the tip of the boom 20; and
• a rear end 42 of the distributor cable 4 has:
  • a first end 421 fixed to wind on a second side of the winding drum 50; and
  • a second end 422 opposite fixed to wind on the small drum 62 of the tensioning mechanism 6;
  • where this rear run 42 passes through a deflection pulley 43 disposed at the foot of the boom 20.

Thus, the front run 41 has a length substantially equivalent to twice the length of the boom 20, while the rear run 42 has a length substantially equivalent to the length of the boom 20.

For a displacement of the distributor carriage 3 towards the front, the motor 5 rotates the winding drum 50 in a so-called forward direction of rotation which corresponds to a winding of the front strand 41 on the winding drum 50 and to a winding unwinding of the rear section 42 on the winding drum 50. For a displacement of the distributor carriage 3 towards the rear, the motor 5 rotates the winding drum 50 in a direction of rotation said rear direction, opposite to the forward direction, which corresponds to a unwinding of the front run 41 on the winding drum 50 and a winding of the rear run 42 on the winding drum 50.

• interdire la rotation des tambours 61, 62 selon un premier sens de rotation S1 correspondant à un déroulement du brin avant 41 sur le grand tambour 61 et à un enroulement du brin arrière sur le petit tambour 62 et
• autoriser la rotation des tambours 61, 62 selon un second sens de rotation S2, opposé au premier sens de rotation S1, où ce second sens de rotation S2 correspond à un enroulement du brin avant 41 sur le grand tambour 61 et à un déroulement du brin arrière sur le petit tambour 62.

The differential drum device comprises a main locking system 80 cooperating with the drums 61, 62 for:

• prohibiting the rotation of the drums 61, 62 in a first direction of rotation S1 corresponding to a unwinding of the front strand 41 on the large drum 61 and a winding of the rear strand on the small drum 62 and
• allow rotation of the drums 61, 62 in a second direction of rotation S2, opposite to the first direction of rotation S1, where this second direction of rotation S2 corresponds to a winding of the front strand 41 on the large drum 61 and to a strand unwinding back on the small drum 62.

This first direction of rotation S1 of the drums 61, 62 results in a loosening (or a decrease) of the tension in the distributor cable 4. The function of this main locking system is precisely to prevent such a relaxation of the tension in the 4. On the contrary, this second direction of rotation S2 of the drums 61, 62 results in an increase (or an increase) of the tension in the distributor cable 4.

As visible on the figure 6 , the two drums 61, 62 are mounted on an axis 63, and are more specifically integral in rotation with this axis 63.

• un système à crans unidirectionnel comprenant des crans (ou dents) 81 en périphérie de l'un des tambours 61, 62 ou d'une roue crantée 82 solidaire des tambours 61, 62 ainsi qu'illustré sur la figure 6, et
• au moins un cliquet 83 pivotant propre à se bloquer dans les crans 81 pour un blocage pour interdire la rotation des tambours 61, 62 selon le premier sens de rotation S1, tout en autorisant la rotation des tambours 61, 62 selon un second sens de rotation S2 opposé au premier sens de rotation ; et
• au moins un organe élastique de rappel (non illustré) sollicitant le cliquet 83 vers une position de blocage dans les crans 81.

As illustrated on the figure 6 this main locking system 80 may comprise:

• a unidirectional notch system comprising notches (or teeth) 81 on the periphery of one of the drums 61, 62 or a notched wheel 82 integral with the drums 61, 62 as illustrated on FIG. figure 6 , and
• at least one pivoting pawl 83 adapted to lock in the notches 81 for a locking to prevent the rotation of the drums 61, 62 in the first direction of rotation S1, while allowing the rotation of the drums 61, 62 in a second direction of rotation S2 opposite to the first direction of rotation; and
• at least one elastic return member (not shown) urging the pawl 83 towards a locking position in the notches 81.

The toothed wheel 82 is integral in rotation with the axis 63.

• une configuration fermée dans lequel il coopère avec les tambours 61, 62 pour interdire la rotation des tambours 61, 62 également selon le second sens de rotation S2; et
• une configuration ouverte dans lequel il autorise la rotation des tambours 61, 62 selon ce second sens de rotation S2.

The tensioning mechanism 6 may also comprise a secondary locking system 90 selectively movable between:

• a closed configuration in which it cooperates with the drums 61, 62 to prevent the rotation of the drums 61, 62 also in the second direction of rotation S2; and
• an open configuration in which it allows the rotation of the drums 61, 62 according to this second direction of rotation S2.

This secondary locking system 90 is distinct from the aforementioned main locking system. The second direction of rotation S2 of the drums 61, 62 is recalled as an increase (or increase) of the tension in the distributor cable 4.

• en configuration fermée, pendant le travail de distribution de la charge par le chariot distributeur 3 le long de la flèche 20, bloquer la rotation des tambours 61, 62 selon ce second sens de rotation, ces tambours 61, 62 étant par ailleurs déjà bloqués en rotation selon le premier sens de rotation grâce au système de blocage principal ; et
• en configuration ouverte, pendant la mise en tension du câble distributeur 4, ainsi que décrit ultérieurement, autoriser la rotation des tambours 61, 62 selon ce second sens de rotation S2, cette rotation selon ce second sens de rotation S2 étant nécessaire pour tendre le câble distributeur 4.

This secondary locking system 90 has the following functions:

• in the closed configuration, during the work of distributing the load by the distributor carriage 3 along the arrow 20, blocking the rotation of the drums 61, 62 according to this second direction of rotation, these drums 61, 62 being moreover already blocked in rotation in the first direction of rotation by means of the main locking system; and
• in the open configuration, during the tensioning of the distributor cable 4, as described later, allow the rotation of the drums 61, 62 according to this second direction of rotation S2, this rotation according to this second direction of rotation S2 being necessary to tension the cable distributor 4.

The Figures 7 to 9 illustrate an exemplary embodiment of such a secondary locking system 90, being noted that this example of secondary locking system 90 is not illustrated in the other figures.

• un système à crans unidirectionnel comprenant des crans (ou dents) 91 en périphérie de l'un des tambours 61, 62 ou d'une roue crantée 92 solidaire des tambours 61, 62, et
• un cliquet 93 pivotant propre à se bloquer dans les crans 91 pour un blocage pour interdire la rotation des tambours 61, 62 selon le second sens de rotation S2 ; et
• au moins un organe élastique de rappel (non illustré) sollicitant le cliquet 93 vers une position de blocage dans les crans 91 ; et
• un actionneur 94 mobile déplaçable sélectivement entre :
  • une position de repos (visible sur la figure 8) dans laquelle l'actionneur 94 n'agit pas sur le cliquet 93 qui reste en position de blocage dans les crans 91 pour interdire la rotation des tambours 61, 62 selon le second sens de rotation S2 ; et
  • une position de déverrouillage (visible sur la figure 9) dans laquelle l'actionneur 94 agit sur le cliquet 93 (en appuyant dessus) pour le débloquer des crans 91 et ainsi autoriser la rotation des tambours 61, 62 selon le second sens de rotation S2.

This secondary locking system 90 comprises:

• a unidirectional detent system comprising notches (or teeth) 91 on the periphery of one of the drums 61, 62 or a toothed wheel 92 integral with the drums 61, 62, and
• a pivoting pawl 93 adapted to lock in the notches 91 for locking to prevent the rotation of the drums 61, 62 in the second direction of rotation S2; and
• at least one elastic return member (not shown) urging the pawl 93 to a locking position in the notches 91; and
• a movable actuator 94 movable selectively between:
  • a rest position (visible on the figure 8 ) in which the actuator 94 does not act on the pawl 93 which remains in the locked position in the notches 91 to prevent the rotation of the drums 61, 62 in the second direction of rotation S2; and
  • an unlocking position (visible on the figure 9 ) in which the actuator 94 acts on the pawl 93 (pressing on it) for the to unlock notches 91 and thus allow the rotation of the drums 61, 62 in the second direction of rotation S2.

The toothed wheel 92 is integral in rotation with the axis 63. It is conceivable that the two drums 61, 62 are framed by the toothed wheel 82 on one side and the toothed wheel 92 on the other side.

This secondary locking system 90 is thus reversed in its operation with respect to the main locking system 80. Thus, the notches 91 are turned in the opposite direction relative to the notches 81.

The pawl 93 is mounted on the distributor carriage 3 and remains in the locking position (visible on the Figures 7 and 8 ) during the work of distribution of the load by the distributor carriage 3, thus blocking the rotation of the drums 61, 62 in the second direction of rotation S2.

The actuator 94 is mounted on the boom of the crane, at the foot of the boom, and occupies its rest position during the work of distribution of the load by the distributor carriage 3, without acting with the pawl 93; the secondary locking system 90 is then in closed configuration.

On the other hand, upstream or at the beginning of the automated tensioning process, when the distributor carriage 3 is at the end of the jib, the actuator 94 is controlled towards its unlocking position in order to unlock the pawl 93 and thus allow the drums 61 to rotate. 62 in the second direction of rotation S2; the secondary locking system 90 is then in open configuration.

The tensioning device 1 further comprises an automated control system 10 which makes it possible to control the tensioning of the dispenser cable 4 automatically.

This automated control system 10 comprises an abutment 7 slidably mounted in translation on a fixed structure element 22 of the crane 2 placed at the base of the jib, so that the abutment 7 is situated in front of the distributor carriage 3 when the latter is substantially at the start of the race at the foot of the arrow 20.

This abutment 7 comprises a rod 70 extended by an enlarged head 72. The rod 70 is slidably mounted on the structural element 22 and, as such, the rod 70 passes through this structural element 22 in an orifice or bearing.

The rod 70 has a free end end provided with an abutment surface 71 provided for the distributor carriage 3 to abut against said abutment surface 71. As such, the distributor carriage 3 can have, on the rear, a rear bumper 33 clean to bear on the abutment surface 71.

This abutment surface 71 is widened relative to the rod 70, and is in particular in the form of a larger diameter disc diameter of the rod 70 if it is cylindrical.

• une première extrémité présentant la surface de butée 71 et
• une seconde extrémité présentant la tête élargie 72.

The rod 70 has a rear end, opposite to the front end and therefore to the abutment surface 71, on which is fixed the enlarged head 72. Thus, the abutment 7 has on both sides of the structural element 22:

• a first end having the abutment surface 71 and
• a second end having the enlarged head 72.

The enlarged head 72 has a planar detection surface 73 inclined relative to the direction of sliding DC of the abutment 7 on the structural element 22.

This automated control system 10 further comprises an elastic return member 8 interposed between the structural element 22 and the abutment surface 71, where this return member 8 is in the form of a helical compression spring mounted around it of the stem 70.

The automated control system 10 also comprises a proximity sensor 9 fixedly mounted on the boom 20 and disposed facing the detection surface 73 of the enlarged head 72 of the stop 7, where the proximity sensor 9 is configured to detect and measuring the distance between said proximity sensor 9 and said detection surface 73.

This proximity sensor 9 may for example be an inductive sensor or a light sensor (infrared sensor, etc.).

• une position de repos (visible sur les figures 2, 10 et 11) en l'absence de poussée exercée par le chariot distributeur 3 sur la butée 7, autrement dit en l'absence d'effort de poussée exercé vers l'arrière (autrement dit en direction du pied de flèche) par le butoir arrière 33 du chariot distributeur 3 sur la surface de butée 71 de la butée 7, étant noté que l'organe de rappel 8 sollicite cette butée 7 vers sa position de repos ; et
• plusieurs positions de travail en présence d'un effort de poussée exercé par le chariot distributeur 3 sur la butée 7, autrement dit en présence d'un effort de poussée exercé vers l'arrière par le butoir arrière 33 du chariot distributeur 3 sur la surface de butée 71 de la butée 7, étant noté que l'organe de rappel 8 offre un effort résistant à cet effort de poussée exercé par le chariot distributeur 3 sur la butée 7.

The stop 7 is selectively movable between:

• a rest position (visible on figures 2 , 10 and 11 ) in the absence of thrust exerted by the trolley 3 on the stop 7, that is to say in the absence of pushing force exerted backwards (ie in the direction of the foot of the arrow) by the rear stopper 33 of the trolley distributor 3 on the abutment surface 71 of the abutment 7, being noted that the return member 8 urges the abutment 7 to its rest position; and
• several working positions in the presence of a thrust force exerted by the distributor carriage 3 on the stop 7, in other words in the presence of a thrust force exerted backwards by the rear stopper 33 of the distributor carriage 3 on the surface stop 71 of the abutment 7, being noted that the return member 8 provides a force resistant to this thrust force exerted by the distributor carriage 3 on the stop 7.

In the working positions, the stop 7 has slid (towards the rear), compared to the rest position, which contributes to a modification of the distance between the proximity sensor 9 and the detection surface 73, and also to a compression of the return member 8 between the structural element 22 and the abutment surface 71.

It should be noted that the detection surface 73 is inclined in the direction of a reduction of the distance between the proximity sensor 9 and the detection surface 73 when the stop 7 has slid (towards the rear) from its position of rest towards a working position.

As the proximity sensor 9 is configured to detect and measure the distance between the proximity sensor 9 and the detection surface 73, this proximity sensor 9 is then configured to detect the stop 7 in its rest position and in its positions of job.

• au moteur 5 pour piloter le déplacement du chariot distributeur 3 vers l'avant et vers l'arrière ; et
• au capteur de proximité 9 pour récupérer en temps réel la distance mesurée entre ce capteur de proximité 9 et la surface de détection 73 de la butée 7 ;

de sorte que cette unité de pilotage puisse piloter le moteur 5, et par conséquent un réglage de la tension du câble distributeur 4 (comme décrit ultérieurement), en fonction d'une course de la butée 7 entre sa position de repos et ses positions de travail (autrement dit en fonction de la distance mesurée entre ce capteur de proximité 9 et la surface de détection 73 de la butée 7).The automated control system 10 also comprises a control unit (not shown), preferably placed in the cockpit of the crane 2, which is connected to both:

• the motor 5 to control the movement of the distributor carriage 3 forwards and backwards; and
• the proximity sensor 9 to recover in real time the distance measured between this proximity sensor 9 and the detection surface 73 of the stop 7;

so that this control unit can drive the motor 5, and therefore an adjustment of the tension of the distributor cable 4 (as described later), as a function of a stroke of the stop 7 between its rest position and its positions of work (in other words as a function of the distance measured between this proximity sensor 9 and the detection surface 73 of the abutment 7).

It should be noted that the stop assembly 7, structural element 22, return member 8 and proximity sensor 9 is arranged at the foot of the crane 2 dispensing boom 20, so that the crane driver can have a vision. sufficiently close to the distributor carriage 3 during the automated tensioning process of the distributor cable 4 described below.

This automated tensioning method comprises the following steps.

In a first step, the distributor carriage 3 is placed in a starting position, for example that illustrated in FIGS. Figures 10 and 11 , in which the distributor carriage 3 does not exert thrust on the stop 7. It is conceivable to provide a presence detector (not shown) configured to detect the presence of the distributor carriage 3 in this starting position.

This starting position of the distributor carriage 3 substantially corresponds to a reference position of the distributor carriage 3, which will be updated at the end of the process (as described later), which is its position at the beginning of the race at the foot of the arrow. This reference position serves as a starting point for determining the position of the distributor carriage 3 along the arrow 20.

In this first step or after this first step, it is expected that the secondary locking system 90, when present, switches to open configuration. This switching can be performed by a passive mechanical system or by a motorized system.

In this first step or after this first step, the control unit recovers the departure distance DD measured between the proximity sensor 9 and the detection surface 73 of the stop 7, while the stop 7 is in the rest position. . In other words, it is provided a detection of the stop 7 by the proximity sensor 9 in the rest position; this rest position of the stop 7 corresponding to a start of adjustment stroke.

Prior to this first step or after this first step, the crane driver initiates the sequence of steps under the action of a manual control, for example on an activation button (specific button, button on touch screen,. ..).

• le détecteur de présence a détecté la présence du chariot distributeur 3 en position de départ ;
• la moufle de levage 31 portant l'organe de levage 30 est en position haute non descendue ;
• un effort de charge sur l'organe de levage 30 est mesuré comme étant inférieur à 5 % d'une charge maximale prédéfinie.

The second step is to check if the following conditions are met:

• the presence detector has detected the presence of the distributor carriage 3 in the starting position;
• the lifting muffle 31 carrying the lifting member 30 is in the up position not descended;
• a loading force on the lifting member 30 is measured as less than 5% of a predefined maximum load.

The undescended up position of the lifting block 31 can for example be detected by an electric contactor or by a calibration of the hoist winch encoder (which controls the rise / fall of the muffle 31) indicating the setting of the maximum electrically high position possible.

The third step is performed if the above conditions are met. If necessary, the third step is to control the motor 5 to make a first displacement of the distributor carriage 3 towards the rear (as shown schematically by the arrow D1 on the Figures 12 and 13 ) until it bears on the abutment 7 and exerts a thrust on the abutment 7, against the resilient return member 8, causing displacement of the abutment 7 to a predefined working position (called final working position) detected by the proximity sensor 9, corresponding to an adjustment limit switch.

In other words, and as illustrated in the Figures 12 and 13 , the distributor carriage 3 is moved rearwardly until to a measurement of a predefined end distance DF between the proximity sensor 9 and the detection surface 73 of the stop 7. As explained above, the Starting distance DD is greater than the ending distance DF.

As a reminder, during this first displacement of the distributor carriage 3 towards the rear, the motor 5 rotates the winding drum 50 in the backward direction which corresponds to a unwinding of the front strand 41 on the winding drum 50 and to a winding of the rear end 42 on the winding drum 50

Concomitant with this first displacement of the distributor carriage 3 until the distance measured by the proximity sensor 9 is equal to the predefined end distance DF, the return member 8 exerts a resistive force, which believes as and when measuring the thrust, and therefore the front end 41 of the distributor cable 4 is wound on the large drum 61 of the tensioning mechanism 6 (while unwinding on the winding drum 50) and the rear strand 42 is unwound on the small drum 62 of the tensioning mechanism 6 (while winding on the winding drum 50), so that the tension of the distributor cable 4 increases.

Thus, during this third step, the distributor cable 4 is tensioned by the tensioning mechanism 6 with a differential drum device.

The final tension of the distributor cable 4 will depend on the predefined end distance DF and the elastic return coefficient of the return member 8.

In a fourth step, and as illustrated on the Figures 14 and 15 , the motor 5 is driven to make a second displacement of the distributor carriage 3 towards the front (as shown diagrammatically by the arrow D2 on the Figures 14 and 15 ) until the stop 7 returns to the start of the race (ie a return to the rest position), that is to say until the distance measured by the proximity sensor 9 is equal to the distance of rest DR.

In a fifth step, the control unit performs a reset of the reference position of the distributor carriage 3 when the stop 7 is returned to the start of the stroke following the second displacement of the distributor carriage 3, that is to say when the distance measured by the proximity sensor 9 is equal to the rest distance DR. It should be noted that this zeroing can be done a little before the complete return of the stop 7 at the beginning of the race (in other words a little before the complete release of the return member 8) to have a better control of the position of the distributor carriage 3 pushed by the return member 8 and still retained by the rear end 42 of the cable distributor cable 4.

Thus, this method allows an automated registration of the reference position of the distributor carriage 3, which eliminates any risk of error in this reference position and thus allows to have a range indication (or positioning indication of the carriage distributor 3 along the arrow 20) which will always remain fair and reliable.

• une automatisation du mouvement de tension du câble distributeur 4, avec un pilote de grue qui déclenche la séquence de mise en tension sous l'action d'une commande manuelle ;
• une automatisation qui permet une mise en tension automatique et précise du câble distributeur 4, grâce au mécanisme tendeur 6 avec dispositif à tambour différentiel ;
• un dispositf de tension 1 automatisée qui permet de limiter et de maitriser l'effort dans le câble distributeur 4 (sans risque de sur-tension et de sous tension) ;
• une tension automatisée simple d'utilisation, permettra de diminuer le risque de travail avec un câble distributeur 4 détendu qui pourrait entrainer le déclenchement du dispositif de sécurité du mou de câble ;
• une automatisation qui permet d'effectuer cette mise en tension plus souvent qu'auparavent, améliorant ainsi le déplacement du chariot distributeur 3 qui sera plus réactif et plus précis car il n'y aura plus de mou de câble à retendre avant de déclencher le déplacement du chariot distributeur 3 ;
• une tension automatisée qui permet de remplacer l'intervention manuelle d'un opérateur extérieur de maintenance de maintenance par une action plus facile, sans effort et autonome du pilote de grue, améliorant également la sécurité pendant l'exploitation de la grue 2 ;
• une automatisation des mouvements qui permet de reporter une partie des responsabilités attribués avant aux opérateurs extérieurs de maintenance, au bon déroulement de la séquence donc au constructeur de la grue 2 qui s'engage sur le bon fonctionnement des mouvements et de la fiabilité des composants et du dispositf de tension 1 ;
• une automatisation qui permet de réduire les frais de maintenance, de diminuer les temps d'arrêt de maintenance et donc d'augmenter la productivité sur le chantier et améliorer les coûts d'exploitation de la grue 2, donc une meilleure rentabilité pour le commanditaire du chantier ;
• une mise à zéro automatisée de la position de référence du chariot distributeur 3, qui permet ainsi de toujours indiquer sur un écran de pilotage des bonnes valeurs de portée de la charge, ces valeurs restants précises pourront ainsi être reprises dans un process de contrôle commande de la grue 2.

Therefore, this voltage product has many technical advantages:

• an automation of the tensioning movement of the distributor cable 4, with a crane driver which triggers the tensioning sequence under the action of a manual control;
• an automation that allows automatic and precise tensioning of the distributor cable 4, thanks to the tensioning mechanism 6 with differential drum device;
• an automated voltage device 1 which allows to limit and control the force in the cable distributor 4 (without risk of over-voltage and under voltage);
• a simple automated tension of use, will reduce the risk of working with a cable distributor 4 relaxed which could cause the release of the safety device slack cable;
• an automation that allows this tensioning more often than before, thus improving the movement of the distributor trolley 3 which will be more responsive and more accurate because there will be more slack cable to tighten before triggering the displacement the dispenser carriage 3;
• an automated tension which makes it possible to replace the manual intervention of an outside operator of maintenance maintenance by an easier, effortless and autonomous action of the crane pilot, also improving the safety during the operation of the crane 2;
• an automation of the movements which makes it possible to postpone part of the responsibilities attributed before to the external operators of maintenance, to the good progress of the sequence thus to the manufacturer of the crane 2 which commits itself on the good functioning of the movements and the reliability of the components and voltage device 1;
• automation that reduces maintenance costs, reduces maintenance downtime and therefore increases productivity on the job site and improves the operating costs of crane 2, thus improving profitability for the contractor. construction site ;
• an automatic zeroing of the reference position of the distributor carriage 3, which thus makes it possible to always indicate on a control screen good load range values, these precise remaining values can thus be included in a control process of the crane 2.

Of course the implementation example mentioned above is not limiting in nature and further improvements and details can be made to the tensioning device according to the invention without departing from the scope of the invention. other forms of tensioning mechanism and / or stop may for example be made.

For example, Figures 16 and 17 illustrate an alternative embodiment of the abutment 7 described below, using the same numerical references for similar elements or performing the same functions.

This abutment 7 comprises a rod 70 extended by an enlarged head 72. The rod 70 is slidably mounted on the structural element 22 and passes through this structural element 22 in a hole or bearing 23 visible on the Figures 16 and 17 .

In this variant, the enlarged head 72 supports a secondary rod 74, parallel to the rod 70, and slidably mounted on the structural element 22 in a hole or bearing 24. This a secondary rod 74 provides additional guidance of the translation of the stop 7, and contributes to a better accuracy in the measurement of its displacement.

The rod 70 has a free end end provided with an abutment surface 71 provided for the distributor carriage 3 to abut against said abutment surface 71.

The enlarged head 72 has a planar detection surface 73 inclined relative to the direction of sliding DC of the abutment 7 on the structural element 22.

In this variant, the detection surface 73 is inclined in the direction of increasing the distance between the proximity sensor 9 and the detection surface 73 when the stop 7 has slid (towards the rear) from its rest position. (illustrated in figure 16 ) to the final working position (illustrated in figure 17 ). In other words, the starting distance DD is less than the ending distance DF.

This variant therefore has an advantage in the sense that, in the event of a malfunction with excessive thrust exerted by the distributor carriage 3, there is no risk that the stop 7 comes to tap the proximity sensor 9. In fact, when pushing, the stop 7 moves away from the proximity sensor 9.

Claims (17)

Automated tensioning device (1) for a distributor cable (4) for moving a distributor carriage (3) movable along a crane (2) distributing vane (20), said tensioning device (4) 1) comprising a motor (5) cooperating with the distributor cable (4) to ensure the displacement of the distributor carriage (3) and further comprising a tensioning mechanism (6) coupled to the distributor cable (4) to provide tension control the distributor cable (4), said tensioning device (1) being characterized by further comprising an automated control system comprising: a stop (7) movably mounted on a fixed structure element (22) of the crane (2) between a rest position in the absence of thrust exerted by the distributor carriage (3) on the abutment (7), and several working positions in the presence of a thrust force exerted by the distributor carriage (3) on the stop (7); - A resilient return member (8) urging said stop (7) towards its rest position and offering a force resistant to a thrust force exerted by the distributor carriage (3) on the stop (7); and - a proximity sensor (9) configured to detect the stop (7) in its rest position and its working positions; a control unit connected to the motor (5) and to the proximity sensor (9) for driving said motor (5), and consequently an adjustment of the tension of the distributor cable (4), as a function of a stroke of the stop (7) between its rest position and its working positions. Voltage device (1) according to claim 1, wherein the stop (7) is slidably mounted in translation on the fixed structure element (22) of the crane (2). A tensioning device (1) according to claim 2, wherein the stop (7) has a first end having an abutment surface (71) for the dispensing carriage (3), and a second end having a sensing surface (73). for the proximity sensor (9) positioned opposite this detection surface (73). Voltage device (1) according to claim 3, wherein the detection surface (73) of the stop (7) is a flat surface inclined relative to a direction of sliding (DC) in translation of said stop (7). A tensioning device (1) according to any one of claims 3 and 4, wherein the stop (7) passes through the fixed structural element (22) so that the abutment surface (71) and the detection surface ( 73) are arranged on either side of the fixed structural element (22). A tensioning device (1) according to any one of claims 3 to 5, wherein the resilient return member (8) is interposed between the fixed structural element (22) and the abutment surface (71) provided in the first end of the stop (7). Voltage device (1) according to any one of claims 1 to 6, comprising at least one distribution winch coupled to the motor (5) and comprising a winding drum (50), where: a front end (41) of the distributor cable (4) has a first end (411) fixed on a first side of the winding drum (50) and an opposite second end (412) fixed on the tensioning mechanism (6), this forward strand (41) passing through at least one deflection pulley disposed in a point of the distributor arrow (20); and a rear end (42) of the distributor cable (4) has a first end (421) fixed on a second side of the winding drum (50) and an opposite second end (422) fixed to the tensioning mechanism (6), this rear strand (42) passing through at least one deflection pulley (43) disposed at the foot of the distributor boom (20). A tensioning device (1) according to claim 7, wherein the tensioning mechanism (6) comprises a differential drum device rotatably mounted on the distributor carriage (3) and comprising: two drums (61, 62) of different diameters and integral in rotation, the second end (412) of the front end (41) of the distributor cable (4) being fixed to wind on a drum of larger diameter (61) and the second end (422) of the rear end (42) of the distributor cable (4) being fixed to wind on a smaller diameter drum (62), where the front end (41) and the back end (42) are wound so that, on the one hand, a rotation of the two drums (61, 62 ) in a first direction of rotation (S1) causes unwinding of the front run (41) on the larger diameter drum (61) and winding of the rear run (42) on the smaller diameter drum (62) and, on the other hand, a rotation of the two drums (61, 62) in a second direction of rotation (S2) causes winding of the front run (41) on the larger diameter drum (61) and unwinding of the rear run ( 42) on the smaller diameter drum (62); and - a main locking system (80) cooperating with the drums (61, 62) to prohibit the rotation of the drums (61, 62) in said first direction of rotation (S1). A tensioning device (1) according to claim 8, wherein the tensioning mechanism (6) comprises a secondary locking system (90) selectively movable between: - A closed configuration in which it cooperates with the drums (61, 62) to prevent the rotation of the drums (61, 62) also in the second direction of rotation (S2); and - An open configuration in which it allows the rotation of the drums (61, 62) according to said second direction of rotation (S2). Voltage device (1) according to any one of claims 1 to 9, wherein the proximity sensor (9) is an inductive or luminous sensor. Tensioning device (1) according to any one of claims 1 to 10, wherein the stop (7) is movably mounted on a structural element (22) arranged at the foot of the crane (2) ). Lifting crane (2) comprising a distributor boom (20) along which is movable a distributor carriage (3), said crane (2) comprising a tensioning device (1) according to any one of claims 1 to 11, wherein the distributor carriage (3) is movable in a setting configuration in which the distributor carriage (3) pushes against the stop (7), against the resilient return member (8), causing a moving the stop (7) to a predefined working position detected by the proximity sensor (9). Method of automatically tensioning a distributor cable (4) in a crane (2) according to claim 12, comprising the steps of: - Detection of the stop (7) by the proximity sensor (9) in the rest position, corresponding to a start of adjustment stroke; first movement of the distributor carriage (3) in a first direction of translation until it bears against the abutment (7) and then exerts a thrust on the abutment (7), against the return member (8); ) elastic, causing a displacement of the stop (7) to a predefined working position detected by the proximity sensor (9), corresponding to an adjustment limit switch; - Tensioning of the distributor cable (4) by the tensioning mechanism (6) concomittament to the displacement of the distributor carriage (3) to the end of travel of the stop (7); - Second displacement of the distributor carriage (3) in a second direction of translation, opposite to the first direction of translation, until the return of the stop (7) at the start of travel. A tensioning method according to claim 13, comprising a step of zeroing a reference position of the distributor carriage (3) when the stop (7) is returned to the start of the stroke following the second movement of the distributor carriage (3). A tensioning method according to any one of claims 13 to 14, wherein the first movement of the dispensing carriage (3) is performed from a start position detected by a presence detector, and this movement is allowed with the condition wherein said presence detector has detected the presence of said distributor carriage (3) in the starting position. A tensioning method according to any one of claims 13 to 15, wherein the first movement of the distributor carriage (3) is carried out provided that the following conditions are met: - At least one lifting muffle (31) carrying a lifting member (30) and suspended from the trolley (3) by a lifting cable (32) is in the up position not descended; a loading force on the lifting member (30) is measured as being less than 5% of a predefined maximum load. A tensioning method according to any one of claims 13 to 16, wherein the first movement of the distributor carriage (3) is effected by the action of a manual control exerted by a driver of the crane.

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