ES2795200T3 - Automated tensioning device and procedure of a distributor cable for crane - Google Patents

Abstract

Automated tensioning device (1) of a distributor cable (4) that ensures the movement of a distributor carriage (3) movable along a distributor boom (20) of a crane (2), said tension device (1) comprising ) a motor (5) that cooperates 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 an adjustment of the tension of the distributor cable (4), said tension device (1) being characterized in that it also comprises 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 stop (7) and various working positions in the presence of a thrust force exerted by the distributor carriage (3) on the stop (7); - an elastic return member (8) urging said stop (7) towards its rest position and offering a force resistant to a pushing effort 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) to control said motor (5) and, consequently, an adjustment of the tension of the distributor cable (4), depending on a travel of the stop (7) between its rest position and its working positions.

Description

DESCRIPTION

Automated tensioning device and procedure of a distributor cable for crane

The present invention relates to an automated tensioning device for a distributor cable that ensures the movement of a displaceable distributor carriage along a distributed boom of a crane.

It is also related to a lifting crane, such as a tower crane, comprising a tensioning device of this type, as well as to an automated tensioning method of a distribution cable in a crane of this type.

In the field of cranes, it is known from the previous document FR 2456700 that a tension device is used comprising a motor that cooperates 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 ends of a front end and a rear end of the distributor cable are fixed. It is also known from this document that a tensioning mechanism is provided coupled to the distributor cable to ensure an adjustment of the tension of the distributor cable, where this tensioning mechanism comprises a differential drum device mounted rotatably on the distributor carriage.

The distribution cable generally has a great length, which can exceed 100 meters depending on the boom lengths, which contributes to the extension of the distribution cable during the time of use, so it is essential to re-tension this distribution cable regularly. Generally, it is necessary to re-tension the distribution cable approximately two to three times during the first month of use of the crane, then approximately once a quarter thereafter.

This tensioning of the distributor cable is, in fact, necessary to ensure proper operation of the translation of the distributor carriage that does not accept having a distributor cable slack, since the cable slack safety device would come into action and block the trolley in safety position in accordance with conventional safety requirements and, in particular, with the indications of the European standard EN 14439 on "lifting devices with suspended load - 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, in each movement impulse, the distributor carriage reacts faster when the distributor cable is sufficiently tensioned, since there will be little or no cable slack to recover.

In the example of document FR 2456700, this operation consists of rotating the two drums of different diameters of the differential drum device, according to a first direction of rotation corresponding to a winding of the front rope on the drum of larger diameter, which contributes, of this way, to a winding of a greater length of front line around the drum of larger diameter compared to the concomitant winding of rear line around the drum of smaller diameter; this difference in winding between the two drums contributing to the required tensioning. On the other hand, a ratchet locking system is provided to prevent the rotation of the drums according to a second opposite direction of rotation.

Nowadays, to rotate the two drums of the differential drum device, it is foreseen to do it manually by means of a specific maneuvering key manipulated by an operator placed on the boom. A maneuvering wrench of this type is generally quite long, for example between 70 and 120 centimeters, so that the operator can exert sufficient effort to re-tension the distributor cable. This operation of retensioning the distributor cable constitutes a dangerous maneuver to be carried out at height above the crane boom and adds an additional cost of operating the crane.

The purpose of the present invention is to resolve all or part of the aforementioned drawbacks, proposing a tensioning device for a distribution cable that is automated, autonomous and can be piloted directly by the crane pilot, therefore, without the need for manual intervention. , which contributes, in this way, to improve safety during crane operation and, therefore, to reduce maintenance costs and reduce maintenance downtimes and, therefore, to increase productivity in the construction site and crane operating costs.

To do this, it proposes an automated tensioning device for a distributor cable that ensures the movement of a displaceable distributor trolley along a distributor boom of a crane, said tension device comprising a motor that cooperates with the distributor cable to ensure movement of the distributor carriage and further comprising a tensioning mechanism coupled to the distributor cable to ensure an adjustment of the tension of the distributor cable, said tension device further comprising an automated control system comprising:

- a stop mounted movably on a fixed structure element of the crane between a rest position in absence thrust exerted by the distributor carriage on the stop and various working positions in the presence of a thrust 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 pushing 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 to control said motor and, consequently, an adjustment of the tension of the distributor cable, as a function of a travel of the stop between its rest position and its working positions.

In this way, and as described later, a tensioning device of this type makes it possible to automatically tension the distributor cable by moving the distributor carriage to push the stop, depending on the travel of the stop during this pushing. In other words, this tension device is automated to facilitate the implementation by the crane operator, guarantee good maneuvers and their precision and allow to have a managed repeatability of the sequences and of the efforts placed on the cable (s). ) of distribution.

This tensioning device also makes it possible, as described later, to automatically ensure an update of the "zero range" of the distributor carriage corresponding to the reference position of the distributor carriage to determine its position along the boom, after retention.

The elastic return member is set at a predefined stiffness value as a function of the desired tension in the distributor cable; the return member establishing a progressive resisting force, increasing as the return member is pushed under the effect of the thrust of the carriage, up to a thrust distance chosen to establish a sufficient tensile stress in the distributor cable for the proper operation of the distribution of the distributor car.

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

As a variant, the stop is pivotally mounted on the fixed structure element of the crane.

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

In a particular embodiment, the detection surface of the stop is a flat surface inclined in relation to a direction of movement in translation of said stop.

In this way, the distance between the detection surface and the proximity sensor varies as a function of the translational displacement of the stop.

In a particular embodiment, the stop passes through the fixed structure element, so that the stop surface and the detection surface are arranged on each side of the fixed structure element.

Advantageously, the elastic return member is sandwiched between the fixed structure element and the stop surface provided at the first end of the stop.

According to one possibility of the invention, the tensioning device comprises at least one distribution winch coupled to the motor 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 a second opposite end fixed on the tensioning mechanism, this front end passing through at least one transmission pulley arranged at the tip of the distributor boom ; and

a rear end of the distributor cable has a first end fixed on a second side of the winding drum and a second opposite end fixed on the tensioning mechanism, this rear end passing through at least one transmission pulley arranged at the foot of the distributor boom.

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 integral in rotation, the second end of the front end of the distributor cable being fixed to be wound on a drum of larger diameter and the second end of the rear end of the distributor cable being fixed to be wound on a drum of smaller diameter , where the front rope and the rear rope are wound, so that, on the one hand, a rotation of the two drums according to a first direction of rotation drives an unwinding of the front rope on the drum of larger diameter and a winding of the rear rope on the drum of smaller diameter and, on the other hand, a rotation of the two drums according to a second direction of rotation drives a winding of the front rope on the drum of larger diameter and an unwinding of the rear rope on the drum of smaller diameter; and

- a main locking system that cooperates with the drums to prevent the rotation of the drums according to said first direction of rotation.

This tensioning mechanism with a differential drum device is particularly well suited to the invention, without for this reason other types of tensioning mechanisms can be considered, such as, for example, mechanisms with a swallow drum. It should be noted that the first direction of rotation of the drums of the differential drum device results in a relaxation (or a lowering) of the tension in the distributor cable. It should be noted that a rotation of the two drums according to the second direction of rotation corresponds to a tensioning of the distributor cable, in other words, to an increase in the tension in the distributor cable.

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

- a closed configuration in which it cooperates with the drums to prevent the drums from rotating, likewise, according to the second direction of rotation; and

- an open configuration in which it authorizes the rotation of the drums according to said second direction of rotation.

In this way, during the work of distributing the load by the distributor carriage along the placing 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, which has the advantage of avoiding a resumption of the balancing efforts during changes in the 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 moves in open configuration and, thus, the adjustment of the tension is only authorized in a well defined area, in particular, at the boom foot and as long as said secondary locking system is properly in open configuration.

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

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 structure element arranged at the foot of the placing boom of the crane, so that the crane pilot can have a sufficiently close view of the distributor carriage during the tension adjustment operation.

The present invention also relates to a lifting crane comprising a placing boom along which a distributor trolley is movable, said crane comprising a tension device according to the invention, where the distributor trolley is movable in a configuration adjustment in which the distributor carriage exerts a thrust on the stop, against the elastic return member, which causes a movement of the stop to a predefined working position detected by the proximity sensor

The invention is also related to a method of automated tensioning of a distribution cable in a crane according to the invention, which comprises the following steps:

- detection of the stop by the proximity sensor in the rest position, corresponding to a start of the adjustment travel;

- first displacement of the distributor carriage according to a first translation direction until it rests on the stop, then exerts a push on the stop, against the elastic return member, which causes a movement of the stop to a detected predefined working position by the proximity sensor, corresponding to an end of adjustment travel;

- tensioning of the distributor cable by the tensioning mechanism concomitantly with the displacement of the distributor carriage until the end of the stop;

- second displacement of the distributor carriage according to a second direction of translation, opposite to the first direction of translation, until the stop returns to the start of travel.

In this way, the distributor cable is automatically tensioned, to a tension dependent on the predefined stiffness value of the elastic return member, without manual intervention.

It should be noted that the first translation direction can be a movement direction towards the rear (in other words, in the direction of the boom foot), while the second translation direction is a movement direction towards the front ( in other words, in the direction of the boom tip), if the stop / proximity sensor / elastic return member assembly is located at the boom foot.

However, provision can be made for the first translation direction to be a movement direction towards the front and for the second translation direction to be a movement direction towards the rear, if the stop / proximity sensor / control member assembly elastic return is located on the pen tip.

Advantageously, the tensioning method comprises a step of resetting a reference position of the distributor carriage when the stop has returned to the start of travel following the second displacement of the distributor carriage.

In this way, the tensioning procedure makes it possible to automatically re-establish the "zero reach" of the distributor carriage that corresponds to the reference position of the distributor carriage to determine its position along the boom. With the automation of this new setting, the risk of error about this reference position is eliminated and the range indication will always remain fair and reliable.

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

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

- at least one lifting gear carrying a lifting member and suspended on the distributor carriage by a lifting cable is in the high, un-lowered position;

- a load effort 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 carried out under the action of a manual control exerted by a pilot of the crane.

Other characteristics and advantages of the present invention will become apparent upon reading the detailed description below, of a non-limiting example of implementation, made with reference to the attached figures in which:

figure 1 is a schematic perspective view of a part of the crane according to the invention;

FIG. 2 is a schematic zoom view of zone II of FIG. 1 which is positioned on the stop / proximity sensor / elastic return member assembly;

figure 3 is a schematic view from above of a part of the crane of figure 1;

figure 4 is a schematic side view of a part of the crane of figure 1;

figure 5 is a schematic perspective view from below of a part of the crane of figure 1;

figure 6 is a schematic perspective view of a differential drum device;

figure 7 is a partial schematic view from above of a part of the crane of figure 1, illustrating an embodiment of a secondary locking system;

Figures 8 and 9 are schematic side views of the secondary locking system in position, respectively in a closed configuration (Figure 8) and in an open configuration (Figure 9);

- Figure 10 is a schematic side view of a part of the crane of Figure 1, in a first configuration where the distributor carriage is in contact with the stop during its first movement, the stop then being at the beginning of its travel adjustment;

FIG. 11 is a zoom view of zone XI of FIG. 10;

FIG. 12 is a schematic view equivalent to that of FIG. 10, in a second configuration (which follows the first configuration) where the distributor carriage has completed its first movement and has pushed the stop to a final working position corresponding to a end of adjustment travel;

FIG. 13 is a zoom view of the zone XIII of FIG. 12;

FIG. 14 is a schematic view equivalent to that of FIG. 10 or 12, in a third configuration (which follows the second configuration) where the distributor carriage has made its second movement until the stop returns to the beginning of the journey;

FIG. 15 is a zoom view of the zone XV of FIG. 14; and

Figures 16 and 17 are schematic side views of a variant embodiment of the stop, respectively in a rest position at the beginning 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 tension device 1 according to the invention is provided on a lifting crane 2, of the tower crane type, comprising a placing boom 20 along which a distributor carriage 3 is movable , where the boom 20 is mounted on a tower 21 at the boom foot. Distributor carriage 3 is shaped to distribute a load (not shown) along boom 2.

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

The distributor carriage 3 is movable towards the front (said in another way, in the direction of the tip of the boom) and, likewise, towards the rear (said in another way, in the direction of the foot of the boom).

The tension device 1 is provided to allow an automated adjustment by the crane pilot (or crane operator) of the tension of the distributor cable 4 which ensures the displacement of the distributor carriage 3 towards the front and towards the rear.

This tension device 1 comprises a motor 5 that cooperates 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 an adjustment of the tension of the distributor cable 4 .

As can be seen in Figure 5, the tensioning mechanism 6 is carried by the distributor carriage 3 and comprises a differential drum device mounted rotatably on the distributor carriage 3 and comprising two drums 61, 62 of different diameters:

- a large drum 61 constituting the drum with the largest diameter; and

- a small drum 62 constituting the drum with the smallest diameter;

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

The distribution cable 4 is coupled to a distribution winch mounted to the boom foot and comprising a winding drum 50 driven in rotation by the motor 5 in two opposite directions of rotation, so that the rotation of the motor 5 drives the movement of the Distributor carriage 3 towards the front or towards the rear according to the direction of rotation of the winding drum 50.

The distribution cable 4 is coupled both to the winding drum 50 of the distribution winch and to the drums 61, 62 of the tensioning mechanism 6 as follows, with reference to Figure 10:

- a front end 41 of the distribution cable 4 has:

- a first end 411 fixed to wrap on a first side of the winding drum 50 and

- a second opposite end 412 fixed to wrap on the large drum 61 of the tensioning mechanism 6; - where this front end 41 passes through a transmission pulley (not visible in the figures) arranged at the tip of the boom 20; and

- a rear end 42 of the distribution cable 4 has:

- a first end 421 fixed to wrap on a second side of the winding drum 50; and

- a second opposite end 422 fixed to wrap on the small drum 62 of the tensioning mechanism 6; - where this rear end 42 passes through a transmission pulley 43 arranged at the foot of the boom 20.

Thus, the front end 41 has a length substantially equivalent to twice the length of the boom 20, while the rear end 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 makes the winding drum 50 rotate according to a direction of rotation called the forward direction, which corresponds to a winding of the front line 41 on the winding drum 50 and an unwinding of the line rear 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 according to a direction of rotation called the rear direction, opposite to the front direction, which corresponds to an unwinding of the front line 41 on the winding drum 50 and to a winding of the rear line 42 on the winding drum 50.

The differential drum device comprises a main locking system 80 that cooperates with drums 61, 62 to:

- prevent the rotation of the drums 61, 62 according to a first direction of rotation S1 corresponding to an unwinding of the front rope 41 on the large drum 61 and a winding of the rear rope on the small drum 62 and

- authorizing the rotation of the drums 61, 62 according to 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 rope 41 on the large drum 61 and an unwinding of the rear end on small drum 62.

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

As can be seen in figure 6, the two drums 61, 62 are mounted on a shaft 63 and are more specifically integral in rotation with this shaft 63.

As illustrated in Figure 6, this main locking system 80 may comprise:

- a unidirectional notch system comprising notches (or teeth) 81 in the periphery of one of the drums 61, 62 or of a notched wheel 82 integral with the drums 61, 62, as illustrated in figure 6 and

- at least one pivoting ratchet 83 suitable to lock in the recesses 81 for a lock to prevent the rotation of the drums 61, 62 according to the first direction of rotation S1, while authorizing the rotation of the drums 61, 62 according to a second direction of rotation S2 opposite to the first direction of rotation; and - at least one elastic return member (not illustrated) urging the pawl 83 towards a locking position in the recesses 81.

The notched wheel 82 is integral in rotation with the shaft 63.

The tensioning mechanism 6 can 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, likewise, according to the second direction of rotation S2; and

- an open configuration in which it authorizes the rotation of the drums 61, 62 according to this second direction of rotation S2.

This secondary locking system 90 is different from the primary locking system mentioned above. The second direction of rotation S2 of the drums 61, 62 is translated, as a reminder, in an increase (or an increase) of the tension in the distributor cable 4.

This secondary locking system 90 has the following functions:

- in a closed configuration, during the work of distributing the load by the distributor carriage 3 along the boom 20, blocking the rotation of the drums 61, 62 according to this second direction of rotation, these drums 61, 62 being by other side, already locked in rotation according to the first direction of rotation thanks to the main locking system; and

- in open configuration, during the tensioning of the distributor cable 4, as described later, authorize the rotation of the drums 61,62 according to this second direction of rotation S2, this rotation being according to this second direction of rotation S2 necessary to tension the distribution cable 4.

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

This secondary locking system 90 comprises:

- a unidirectional notch system comprising notches (or teeth) 91 on the periphery of one of the drums 61, 62 or of a notched wheel 92 integral with the drums 61, 62 and

- a pivoting pawl 93 suitable to lock in the recesses 91 for a lock to prevent the rotation of the drums 61, 62 according to the second direction of rotation S2; and

- at least one elastic return member (not illustrated) urging the pawl 93 towards a locking position in the recesses 91; and

- a movable actuator 94 selectively movable between:

- a rest position (visible in figure 8) in which the actuator 94 does not act on the ratchet 93 which remains in a locked position in the recesses 91 to prevent the rotation of the drums 61,62 according to the second direction of rotation S2; and

- an unlocking position (visible in figure 9) in which the actuator 94 acts on the pawl 93 (resting on it) to unlock it from the notches 91 and, thus, authorize the rotation of the drums 61, 62 according to the second direction of rotation S2.

The notched wheel 92 is integral in rotation with the shaft 63. It can be considered that the two drums 61, 62 are framed by the notched wheel 82 on one side and the notched wheel 92 on the other side.

This secondary locking system 90 is thus reversed in operation relative to the main locking system 80. In this way, the notches 91 are rotated in the reverse direction relative to the notches 81.

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

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

On the other hand, upstream or at the beginning of the automated tensioning procedure, when the distributor carriage 3 is at the boom foot, the actuator 94 is commanded towards its unlocking position to unlock the ratchet 93 and, thus, authorize the rotation of the the drums 61,62 according to the second direction of rotation S2; the secondary locking system 90 is then in an open configuration.

The tensioning device 1 further comprises an automated control system 10 that allows to control the tensioning of the distributor cable 4 automatically.

This automated control system 10 comprises a stop 7 mounted sliding in translation on a fixed structure element 22 of the crane 2 positioned at the foot of the boom, so that the stop 7 is located in front of the distributor carriage 3 when the latter is substantially at the beginning of the route at the foot of boom 20.

This stop 7 comprises a rod 70 extended by an enlarged head 72. The rod 70 is slidably mounted on the frame element 22 and, in this regard, the rod 70 passes through this frame element 22 in a hole or bearing.

The rod 70 has a free front end provided with an abutment surface 71 provided so that the distributor carriage 3 comes to abut against said abutment surface 71. In this regard, the distributor carriage 3 can have, on the rear part, a limit rear 33 suitable to come to rest on the abutment surface 71.

This abutment surface 71 is enlarged relative to the rod 70 and is in particular in the form of a disk with a diameter greater than the diameter of the rod 70 if the latter is cylindrical.

The rod 70 has a rear end, opposite to the front end and, therefore, to the stop surface 71, on which the enlarged head 72 is fixed. In this way, the stop 7 has on each side of the structure element 22:

- a first end presenting the abutment surface 71 and

- a second end presenting the enlarged head 72.

The enlarged head 72 has a flat and inclined detection surface 73 in relation to the direction of movement DC of the stop 7 on the frame element 22.

This automated control system 10 further comprises an elastic return member 8 sandwiched between the structure element 22 and the stop surface 71, where this return member 8 is in the form of a helical compression spring mounted around the rod 70.

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

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

The stop 7 is selectively movable between:

- a rest position (visible in Figures 2, 10 and 11) in the absence of thrust exerted by the distributor carriage 3 on the stop 7, in other words, in the absence of thrust exerted towards the rear (said of otherwise, in the direction of the boom foot) by the rear limit 33 of the distributor carriage 3 on the stop surface 71 of the stop 7, it being noted that the return member 8 urges this stop 7 towards 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 towards the rear by the rear limit 33 of the distributor carriage 3 on the stop surface 71 of the stop 7, it being noted that the return member In the working positions, the stop 7 has moved (towards the rear), compared to the rest position, which contributes to a change in the distance between the proximity sensor 9 and the detection surface 73 and also to a compression of the return member 8 between the frame element 22 and the abutment surface 71.

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

Since 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 work positions.

The automated control system 10 also comprises a steering unit (not illustrated), preferably placed in the cockpit of the crane 2, which is connected at the same time:

- to the motor 5 to control the displacement of the distributor carriage 3 towards the front and towards the rear; and - to the proximity sensor 9 to retrieve in real time the distance measured between this proximity sensor 9 and the detection surface 73 of the stopper 7;

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

It should be noted that the stop assembly 7, structure element 22, return member 8 and proximity sensor 9 is arranged at the foot of the placing boom 20 of the crane 2, so that the crane pilot can have a vision as close enough to the distributor trolley 3 during the automated tensioning of the distributor cable 4 described below.

This automated tensioning procedure comprises the following steps.

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

This starting position of the distributor carriage 3 corresponds substantially to a reference position of the distributor carriage 3, which will be updated at the end of the procedure (as described later), which is its position at the start of travel at the level of the boom foot. This reference position serves as the starting point for determining the position of the distributor carriage 3 along the boom 20.

In this first stage or after this first stage, provision is made for the secondary locking system 90, when present, to pivot in the open configuration. This tilting can be carried out by a passive mechanical system or by a motorized system.

In this first stage or after this first stage, the control unit recovers the starting distance DP 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, a detection of the stop 7 is provided by the proximity sensor 9 in the rest position; this rest position of the stop 7 corresponding to a start of the adjustment travel.

As prior to this first stage or after this first stage, the crane pilot begins the sequence of stages under the action of a manual control, for example, on an activation button (specific button, button on touch screen, ... ).

The second stage consists of verifying if the following conditions are met:

- the presence detector has detected the presence of the distributor carriage 3 in the starting position;

- the lifting gear 31 carrying the lifting member 30 is in the high, non-lowered position;

- a loading effort on the lifting member 30 is measured as being less than 5% of a predefined maximum load.

The undescended high position of the lifting gear 31 can be detected, for example, by an electrical contactor or by a calibration of the encoder of a lifting winch (which commands the lifting / lowering of the lifting gear 31) indicating the setting of the maximum high position electrically possible.

The third stage is carried out if the conditions mentioned above are met. If necessary, the third stage consists of piloting the motor 5 to make a first movement of the distributor carriage 3 towards the rear (as shown by the arrow D1 in Figures 12 and 13) until it comes to rest on the stop 7 and exerting a thrust on the stop 7, against the elastic return member 8, which causes a movement of the stop 7 to a predefined working position (called the final working position) detected by the proximity sensor 9, corresponding to an end of adjustment travel.

In other words and as illustrated in Figures 12 and 13, the distributor carriage 3 moves towards the rear until 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 DP 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 rear direction corresponding to an unwinding of the front rope 41 on the winding drum 50 and a winding of the rope rear 42 on winding drum 50

Concomitantly 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 increases as the thrust is produced and consequently, the front end 41 of the distributor cable 4 is wound on the large drum 61 of the tensioning mechanism 6 (unrolling at the same time on the winding drum 50) and the rear end 42 is unwound on the small drum 62 of the tensioning mechanism 6 (coiling at the same time on the winding drum 50), so that the tension of the distributor cable 4 increases.

In this way, during this third stage, the distribution cable 4 is tensioned by the tensioning mechanism 6 with a differential drum device.

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

In a fourth stage and as illustrated in Figures 14 and 15, the motor 5 is piloted to effect a second movement of the distributor carriage 3 towards the front (as schematized by the arrow D2 in Figures 14 and 15) until the return of the stop 7 to the start of travel (that is, a return to the rest position), in other words, until the distance measured by the proximity sensor 9 is equal to the rest distance DR.

In a fifth stage, the control unit performs a zeroing of the reference position of the distributor carriage 3 when the stop 7 has returned to the start of travel as a continuation of the second displacement of the distributor carriage 3, that is, when the measured distance by the proximity sensor 9 is equal to the rest distance DR. It should be noted that this resetting can be done a little before the complete return of the stop 7 to the beginning of the stroke (in other words, a little before the complete relaxation of the return member 8) to have a better management of the position of the distributor carriage 3 pushed by the return member 8 and always held by the rear end 42 of the distributor cable 4.

In this way, this procedure allows a new automated establishment of the reference position of the distributor carriage 3, which eliminates any risk of error on this reference position and thus allows to have a range indication (or indication of positioning of the distributor carriage 3 along the boom 20) that will always remain fair and reliable.

Consequently, this tensioning procedure has a number of technical advantages:

- an automation of the tension movement of the distributor cable 4, with a crane pilot that 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 a differential drum device;

- an automated tension device 1 that makes it possible to limit and manage the effort in the distributor cable 4 (without risk of overvoltage and undervoltage);

- a simple automated tension to use, will make it possible to reduce the risk of working with a slack distributor cable 4 which could drag the triggering of the cable slack safety device;

- an automation that makes it possible to carry out this tensioning more often than before, which improves, in this way, the displacement of the distributor carriage 3 which will be more reactive and more precise, since there will no longer be any slack in the cable to be re-tensioned earlier to trigger the displacement of the distributor carriage 3;

- an automated tension that makes it possible to replace the manual intervention of an external maintenance operator with an easier, effortless and autonomous action of the crane pilot, which also improves safety during the operation of the crane 2;

- an automation of the movements that makes it possible to transfer a part of the responsibilities previously assigned to the external maintenance operators, to the proper development of the sequence, therefore, to the manufacturer of the crane 2 who is committed to the proper functioning of the movements and the reliability of the components and of the tension device 1;

- an automation that allows to reduce maintenance costs, reduce maintenance downtimes and, therefore, increase productivity on the construction site and improve the operating costs of the crane 2, therefore, better profitability for the sponsor of the work;

- an automated zeroing of the reference position of the distributor carriage 3, which thus makes it possible to always indicate on a pilot screen good values of the load range, these values, which remain precise, may, in this way, resume in a crane command control process 2.

Of course, the implementation example mentioned above does not have any limiting character and other improvements and details can be provided to the tensioning device according to the invention, without thereby departing from the scope of the invention where, for example, other forms of tensioning and / or stop mechanism.

By way of example, Figures 16 and 17 illustrate a variant embodiment of the stopper 7 described below, using the same numerical references for elements that are similar or that fulfill the same functions.

This stop 7 comprises a rod 70 extended by an enlarged head 72. The rod 70 is slidably mounted on the frame element 22 and passes through this frame element 22 in a hole or bearing 23 visible in 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 frame element 22 in a hole or bearing 24. This a secondary rod 74 provides additional guidance for the translation of the stop 7 and contributes to better precision in measuring its displacement.

The rod 70 has a free front end provided with a stop surface 71 provided so that the distributor carriage 3 comes to abut against said stop surface 71.

The enlarged head 72 has a flat and inclined detection surface 73 in relation to the direction of movement DC of the stop 7 on the frame element 22.

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

Therefore, this variant has an advantage in the sense that, in the event of a malfunction with too great a thrust exerted by the distributor carriage 3, there is no risk of the stop 7 hitting the proximity sensor 9 Indeed, during pushing, the stop 7 moves away from the proximity sensor 9.

Claims (17)

1. Automated tensioning device (1) of a distributor cable (4) that ensures the movement of a distributor carriage (3) movable along a distributor boom (20) of a crane (2), said tension device comprising (1) a motor (5) that cooperates with the distributor cable (4) to ensure the displacement of the distributor carriage (3) and which further comprises a tensioning mechanism (6) coupled to the distributor cable (4) to ensure an adjustment of the tension of the distributor cable (4), said tension device (1) being characterized in that it also comprises 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 stop (7) and various positions of work in the presence of a thrust effort exerted by the distributor carriage (3) on the stop (7); - an elastic return member (8) urging said stop (7) towards its rest position and offering a force resistant to a pushing effort 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) to control said motor (5) and, consequently, an adjustment of the tension of the distributor cable (4), depending on a travel of the stop (7) between its rest position and its working positions. Tension device (1) according to claim 1, in which the stop (7) is mounted slidingly in translation on the fixed structure element (22) of the crane (2). Tension device (1) according to claim 2, in which the stop (7) has a first end presenting a stop surface (71) for the distributor carriage (3) and a second end presenting a stop surface (3). detection (73) for the proximity sensor (9) positioned in front of this detection surface (73). Tension device (1) according to claim 3, in which the detection surface (73) of the stop (7) is a flat surface inclined in relation to a direction of movement (DC) in translation of said stop (7 ). Tensioning device (1) according to any one of Claims 3 and 4, in which the stop (7) passes through the fixed structure element (22), so that the stop surface (71) and the surface of Detection (73) are arranged on each side of the fixed frame element (22). Tension device (1) according to any one of claims 3 to 5, in which the elastic return member (8) is sandwiched between the fixed structure element (22) and the stop surface (71) provided in the first end of the stopper (7). Tension 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 a second opposite end (412) fixed on the tensioning mechanism (6), passing this front end (41) by at least one transmission pulley arranged at the tip of the placing boom (20); and - a rear end (42) of the distribution cable (4) has a first end (421) fixed on a second side of the winding drum (50) and a second opposite end (422) fixed on the tensioning mechanism (6), this rear end (42) passing through at least one transmission pulley (43) arranged at the foot of the placing boom (20). Tension 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 be wound on a drum of greater diameter (61) and the second end (422) of the rear end (42) of the distributor cable (4) fixed to wrap on a drum of smaller diameter (62), where the front end (41) and the rear end (42) are wound, so that , on the one hand, a rotation of the two drums (61,62) according to a first direction of rotation (S1) drives an unwinding of the front rope (41) on the drum with a larger diameter (61) and a winding of the rear rope ( 42) on the drum of smaller diameter (62) and, on the other hand, a rotation of the two drums (61, 62) according to a second direction of rotation (S2) drags a winding of the front rope (41) on the drum of larger diameter (61) and unwinding of the rear end (42) on the smaller diameter drum (62); and - a main locking system (80) that cooperates with the drums (61, 62) to prevent the rotation of the drums (61, 62) according to said first direction of rotation (S1). Tension device (1) according to claim 8, in which 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), likewise, according to the second direction of rotation (S2); and - an open configuration in which it authorizes the rotation of the drums (61,62) according to said second direction of rotation (S2). 10. Tension device (1) according to any one of claims 1 to 9, wherein the proximity sensor (9) is an inductive or light sensor. Tension device (1) according to any one of claims 1 to 10, in which the stop (7) is movably mounted on a frame element (22) arranged at the foot of the placing boom (20) of the crane (2). Lifting crane (2) comprising a placing boom (20) along which a distributor trolley (3) is movable, said crane (2) comprising a tension device (1) according to any one of the claims 1 to 11, where the distributor carriage (3) is movable in an adjustment configuration in which the distributor carriage (3) exerts a thrust on the stop (7), against the elastic return member (8), which causes the movement of the stop (7) to a predefined working position detected by the proximity sensor (9). 13. Method of automated tensioning of a distribution cable (4) in a crane (2) according to claim 12, comprising the following steps: - detection of the stop (7) by the proximity sensor (9) in the rest position, corresponding to a start of the adjustment travel; - first displacement of the distributor carriage (3) according to a first translation direction until it rests on the stop (7), then exerts a push on the stop (7), against the elastic return member (8), which causes a movement of the stop (7) to a predefined working position detected by the proximity sensor (9), corresponding to an end of adjustment travel; - tensioning of the distributor cable (4) by the tensioning mechanism (6) concomitantly with the displacement of the distributor carriage (3) until the end of the stop (7); - second displacement of the distributor carriage (3) according to a second translation direction, opposite to the first translation direction, until the stop (7) returns to the start of the journey. 14. Tensioning method according to claim 13, comprising a step of resetting a reference position of the distributor carriage (3) when the stop (7) has returned to the start of travel following the second displacement of the distributor carriage ( 3). Tensioning method according to any one of claims 13 and 14, in which the first movement of the distributor carriage (3) is carried out from a starting position detected by a presence detector and this movement is authorized under the condition that said presence detector has detected the presence of said distributor carriage (3) in the starting position. Tensioning method according to any one of claims 13 to 15, in which the first movement of the distributor carriage (3) is carried out provided that the following conditions are met: - at least one lifting gear (31) carrying a lifting member (30) and suspended on the distributor carriage (3) by a lifting cable (32) is in the high, undescended position; - a load effort on the lifting member (30) is measured as being less than 5% of a predefined maximum load. Tensioning method according to any one of claims 13 to 16, in which the first movement of the distributor carriage (3) is carried out under the action of a manual control exerted by a pilot of the crane.