EP1301431A1

EP1301431A1 - Articulated jib crane

Info

Publication number: EP1301431A1
Application number: EP01944862A
Authority: EP
Inventors: Jean-Marc Yerly
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-07-11
Filing date: 2001-07-10
Publication date: 2003-04-16
Anticipated expiration: 2021-07-10
Also published as: AU6725501A; DE60113546T2; AU2001267255B2; WO2002004336A1; US20040026350A1; DE60113546D1; EP1301431B9; ATE304988T1; EP1301431B1; NZ524020A; EP1172323A1; CA2414173A1

Abstract

The invention concerns a load lifting and handling appliance with articulated jib, capable of being raised and inclined, comprising a mast, a jib foot articulated in rotation at its first end (35) to the top of the mast (21, 22, 29), a fly jib (41) articulated in rotation at the second end (36, 37) of the jib foot, said fly jib comprising on either side of its hinge pin (45) to the fly jib foot respectively a fly jib point (43) and a counter fly jib (42, 49), a jib-retaining assembly comprising at least a king post (16) and a jib tie (25), and at least a double acting stick cylinder (3) linking the jib foot to the fly jib, determining the angle between jib foot and fly jib. The foot portion proximate to said second end and the counter fly jib having conjugated shapes enabling the fly jib point to be urged in aligned position with the jib foot. The lifting appliance may comprise a mobile counterweight system (113).

Description

CRANE WITH ARTICULATED BOOM

The present invention relates to a lifting device with a distributing boom working in articulated mode or in lifting mode for lifting and handling loads comprising a pylon, a jib foot articulated in rotation at its first end at the top of the pylon, an articulated dart in rotation at the second end of the jib foot, said dart comprising on either side of its axis of articulation at the jib foot respectively a dart point and a counter-dart, an arrow retaining assembly comprising at least a punch and an arrow rod, and at least one double-acting articulation cylinder connecting the arrow foot to the dart, determining the angle between the arrow foot and dart.

To allow the handling of loads on construction sites, cranes with a horizontal directional distributing jib are usually used on which slides a carriage serving as a guide for suspension means.

In certain circumstances, for example when the sites are congested or when national legislation prohibits overflight of plots adjacent to the site, they are preferred either cranes with lifting and tilting distributing jib, or cranes with articulated orientable distributing jib. Cranes with lifting distributing jibs have the advantage, compared to horizontal jib cranes of comparable pylon heights, of being able to bring loads to greater heights.

However, these two types of cranes have certain disadvantages compared to horizontal jib cranes. On the one hand, their minimum spans being relatively high, the handling of loads in the immediate vicinity of the base of the cranes cannot be insured. On the other hand, it is very difficult to control a regularity of the speed of distribution of the loads which makes it possible to avoid any untimely swaying.

Patent FR 2605619 describes a crane of defined type of entry, which combines the effects of an articulated distributing jib crane with those of a lifting distributing jib crane, thus giving it a certain versatility. In addition, the mast of this crane has the advantage of being foldable and foldable and this automatically.

However, due to the design of the articulations of the distributing jib, this crane always has a significant minimum reach. In addition, the gain in height under hook obtained when the tip of the boom is raised remains relatively small, not being able to exceed an angular amplitude equivalent to 30 ° relative to the horizontal, due to the angle that the dart always forms. and the arrowhead.

On the other hand, when this crane is folded up and placed on a rolling carrying chassis, specially designed for its transport, the road assembly thus formed is barely allowed to pass under a 4-meter gauge, authorizing it to access the road network. However, this set cannot circulate on certain secondary axes with restricted gauge.

The aim of the present invention is to produce a lifting device with a versatile orientable distributing jib, which can just as easily be used as a lifting distributing jib crane as as an articulated distributing jib crane or even as a tilting jib crane, the transformation from one function to another must be done as simply as possible.

Another object of the present invention is to produce a lifting device with an adjustable distributing jib. versatile which, when working like an articulated jib crane, has a very low minimum reach, but the highest possible maximum reach.

Another object of the present invention is to produce a lifting device with a versatile orientable distributing jib capable of distributing a load with a regular speed, in particular with a constant horizontal speed when it works like a crane with an articulated distributing jib.

Another object of the present invention is to produce a lifting device with a versatile orientable distributing jib which, when it works like a crane with a lifting distributing jib, allows the highest hook height possible.

The aim of the present invention is finally to produce a lifting device with a versatile orientable distributing jib which, when the jib is articulated on an articulated pylon, can be folded up as compactly as possible so that it can be placed in a marine-type container for transport.

To this end, the subject of the present invention is a lifting device with an adjustable distributing boom working in articulated mode or in lifting mode for the lifting and handling of loads as defined from the start, in which the part of the boom foot close to said second end and the counter-dart have conjugate shapes allowing the dart point to come into position aligned with the arrow foot.

The arrow rod can be connected to the dart tip by passing through at least one lifting strut secured to the dart. The lifting strut can be arranged substantially at the junction between the counter-dart and the tip of the dart.

The counter-dart and the part of the jib foot close to its second end may have prismatic profiles and can come into contact with one another when the jib foot and dart are aligned.

The part of the jib foot near its second end may have the shape of a fork with two branches and the counter-dart can be housed in one space between the two branches.

The jib foot can be made up of two parallel beams and the counter-dart can be accommodated in one space between the two beams.

The jib foot and the jib can be connected by two identical articulation cylinders, mounted symmetrically with respect to the vertical plane of symmetry of the lifting machine.

The articulation cylinder or cylinders can directly connect the boom foot to the counter-jib.

The articulation cylinder (s) can directly connect the boom foot and the dart point.

Each articulation cylinder can connect the boom foot and the dart by means of two connecting rods.

Said connecting rods can be articulated to each other and to the jack by the same axis of rotation.

According to a preferred embodiment of the invention, particularly advantageous for tower cranes, the lifting machine comprises a movable counterweight whose position is subject to the angle of inclination of the boom foot. The mobile counterweight thus balances the crane according to the position of the boom.

This mobile counterweight can be fixed to a first end of a pivoting counterweight arm, the second end of which is articulated in rotation with the turret or platform of the lifting machine, on the side opposite the jib. The counterweight is connected to the boom, near the boom foot / dart joint by at least one counterweight cable passing over the punch. The presence of the counterweight cable (s) makes it possible to reduce the importance of the cable and of the boom lifting motor. This counterweight cable can be attached to the dart, in particular to the reinforced part of the dart / boom foot joint.

The other end of the counterweight cable can be attached to the platform, the counterweight cable passing over a pulley carried by the pivoting counterweight arm. In this way, the angle of the swivel arm, and therefore the moment of retention of the counterweight, is directly controlled by the angle of the boom without using an auxiliary motor.

So that the counterweight cable remains perfectly tight, even when the jib foot is fully raised, the pulley can be connected to the pivoting counterweight arm by an equally pivoting pulley arm, articulated to the counterweight arm, and the assembly formed by this pulley and the pulley arm may include weighting means for tensioning the counterweight cable.

Preferably one hoist comprises two counterweight cables passing respectively on either side of the boom foot.

In order to facilitate understanding of the invention, its characteristics and advantages, several embodiments are presented below, with reference to the drawing in which:

- Figure 1 shows in perspective a first embodiment of the lifting device with a distributor boom in the working position in articulated mode and, in the background, in lifting mode;

- Figure 2 shows, in an elevational view, the first embodiment of the lifting device having a distributor boom in the folded position along the pylon;

- Figure 3 shows, in superimposed views in elevation, different stages of folding the pylon of the first embodiment of the lifting machine;

- Figures 4a to 4d show, in elevational views, the different stages of transformation from the articulated mode to the lifting mode of the distributing boom of the first embodiment of the lifting machine;

- Figure 5 shows, in an elevational view, the first embodiment of the lifting device in the folded position;

- Figures 6a to 6c show, in elevation views, different means for transporting the first embodiment of the lifting device.

- Figure 7 shows, in superimposed views in elevation, different phases of operation of the first embodiment of the lifting device with a distributor boom in the working position in lifting mode;

- Figure 8 shows, in a perspective view, the detail of a device for blocking the distributor boom in the working position in the lifting mode of the second embodiment of the lifting machine; - Figure 9 shows in perspective a second embodiment of the lifting device with a distributor boom in the working position in articulated mode and, in the background, in lifting mode;

- Figure 10 shows, in a perspective view, the articulation by cylinder between boom and dart foot of a variant of the second embodiment of the lifting device in the working position in articulated mode.

- Figure 11 shows, in an elevational view, the articulation by cylinder between the foot of the arrow and dart of the variant of Figure 10, with the distributor arrow in the folded position.

- Figures 12a, 12b and 12c show, in schematic elevation views, a third embodiment of the lifting device, with its distributing boom respectively in articulated, lifting and tilting mode.

- Figures 13a and 13b show in perspective views the joint, respectively with a cylinder and two cylinders, between the boom foot and jib of the third embodiment of the lifting device in the working position in articulated mode.

- Figures 14a, 14b, 14c, 14d, 14e, 14f and 14g schematically show variants of the articulation by jack (s) between the jib foot and dart of the third embodiment, in the working position in articulated mode.

- Figure 15 shows an embodiment of the lifting device with a movable counterweight.

- Figure 16 shows another embodiment of the lifting device with a mobile counterweight. - Figure 17 shows an enlarged view of the mobile counterweight system.

To simplify the drafting and facilitate understanding of the invention, identical reference numbers have been given in several figures to identical or equivalent parts of several variant embodiments

The first embodiment of the lifting device with an adjustable distributing jib working in articulated mode or in lifting mode for lifting and handling loads as shown in FIG. 1 comprises a folding pylon made up of two articulated sections l one to the other, namely a pylon foot 21 and an upper pylon 22. The pylon foot is pivotally mounted around a horizontal axis on the front part of a rotating chassis or turret 12. The upper pylon carries, pivoting about a horizontal articulation 26, on the one hand a distributing arrow 31, 41 articulated and liftable and, on the other hand, two symmetrical punches 16 connected at their end by an axis carrying two pulleys 17. The turret 12 is mounted pivoting about a vertical axis on a supporting frame 11.

The pylon is kept in the working position thanks to a set of elements consisting of a ballast 13 fixed to the rear part of the turret 12, straightening struts 23 connecting the pylon to the turret, two tie rods 25, all connected to a control device not shown in the drawing, which may for example be a winch placed on the turret 12, the two tie rods passing respectively over the two pulleys 17 of the punches 16.

The articulated and lifting distributing jib consists of two main parts, namely a jib foot 31 and a dart 41, articulated to one another.

The lower end 35 of the jib foot 31 is connected, by means of the horizontal articulation 26, at the top of the upper pylon 22. The other end 36 of the boom foot is connected, by means of a horizontal articulation 45, to the dart 41. The articulation 45 divides the dart 41 into two asymmetrical parts, namely a counter-dart 42, carrying at its end two pulleys 44, and a dart point 43, carrying at its end 46 two pulleys guiding load suspension means consisting of a lifting cable 53, a muffle and d 'a lifting hook 54.

As shown in the foreground of Figure 1, when the end 46 of the dart tip 43 is in position A, the distributor boom is in the working position in articulated mode. The tie rods 25 pass successively in the grooves of the pulleys 17 of the two punches 16, then in those of the two pulleys 44 of the counter-dart 42, and are fixed to the dart 41. The tie-rods 25 form with the jib foot 31, the two punches 16 and the counter-dart 42 a deformable quadrilateral. This geometrical configuration allows the end 46 of the tip of the dart 43 to move along an approximately flat and horizontal trajectory, represented by dashed line 51.

In the background of FIG. 1, when the end 46 of the dart point 43 is in position B, the distributing arrow is in the working position in lifting mode. The dart 41 is aligned with the arrow foot 31. It can be seen that the tie rods 25 are fixed on the dart 41, near the end 46 of the dart tip 43. In this configuration, these tie rods 25 no longer pass as on the pulleys 17 of the two punches 16, and now form a triangle with the two punches 16 and the aligned assembly arrowhead 31 - dart 41.

The part in the background and in perspective of FIG. 1 showing the dispensing boom in the working position in lifting mode, shows that the boom foot 31 is in fact consisting of two parallel beams 31a and 31b mounted laterally on either side, on the one hand, of the upper pylon 22, and, on the other hand, of the dart 41.

Such a construction with two beams is advantageous. Indeed, the counter-dart 42 can be housed within the slot or 1 spacing 34 between these two beams 31a and 31b and perfect alignment of the dart 41 with the jib foot 31 is then obtained, which, as described below, allows a significant gain in hook height compared to the versatile arrows of the prior art which have a bent shape.

In addition, such a construction with two beams strengthens the structure of the lifting device by providing better resistance to torsion.

The general movement of the assembly in articulated mode, governed by the particular geometry of the quadrilateral (44, 45, 26, 17), is known from the prior art. It is however important to highlight the role played by two of the elements of the lifting device, namely the movement control system and the slot between the two beams of the boom foot.

In a configuration in articulated mode in which the end 46 of the dart point 43 is for example in position A, the device controlling the tie rods 25 can be blocked so as to keep the distance between the pulleys 17 and 44 constant for all the phases of modification of the angle of the articulation of the distributing arrow.

The control device (1) of the joint 45 consists of a system of rods and double-acting cylinder (s), which will be described in detail below. In order to bring the end 46 of the dart point 43 to the position D corresponding to the minimum reach of the lifting machine, the operation is carried out simply by the relative movement of the rod relative to the cylinder of the jack or jacks. The lifting hook 54 progressively approaches the pylon.

Thanks to this simple mode of controlling the angle of the jib foot / dart, it becomes easy to control the regularity of the translation speed of the end 46 of the dart tip and thus avoid any untimely swinging of the load. during its handling.

During the horizontal movement shortening the range, the end 46 of the dart point 43 passes through the intermediate position C, corresponding approximately to the position of minimum range which was obtained with the lifting devices of the prior art. Now, due to the presence of the slot or spacing 34 between the two beams 31a and 31b of the jib foot 31 which allows the dart point 43 to lodge there, the movement can continue until bringing the end 46 of the dart point 43 in position D, all against the arrow foot. This position D corresponds to the minimum range of the hoist.

Starting from this position D corresponding to the minimum range and to return to position A, it suffices to operate the reverse movement of the rod of the articulation cylinder (s), while maintaining the locking of the control device. tie rods 25 so that the end 46 of the tip of the dart 43 progressively moves away from the top of the upper pylon 22.

Continuing the movement beyond position A, still maintaining the blocking of the tie rods control device 25, the articulated mode is transformed into the liftable mode of the distributing boom. As symbolized by the white arrows 56, 57 in FIG. 4a, the arrow base 31 lowers and the end 46 of the tip of the dart straightens. In FIG. 4b, the tie rods 25 are almost aligned with the dart 41. In FIG. 4c, the jib foot continues its descent, the tie rods 25 are then separated from the pulleys 44 of the counter-dart 42.

Finally, in FIG. 4d, the position of the point of attachment 48 of the tie rods 25 on the tip of the dart 43 becomes apparent. The jib 41 is perfectly aligned with the jib foot 31. A locking device 61, described below, now this alignment can be provided optionally, in addition to the jack system (1). The dispensing boom is then in the working position in lifting mode. The end 46 of the dart point 43 being in position E, the distributing arrow is already inclined by a few degrees relative to the horizontal.

FIG. 8 shows in detail the elements constituting the blocking device 61 integral, on the one hand, with each of the two beams 31a and 31b of the jib foot 31 and, on the other hand, with the counter-dart 42 of the dart 41 and cooperating together in order to keep the dart 41 and the jib foot 31 aligned. To make it easier to understand, the tie rods and the articulation cylinder system have been omitted in this figure.

Under each of the two beams 31a and 31b are projecting and placed vis-à-vis respectively a part 62a and a part 62b. In each of these two parts is a locking cylinder 63a and 63b respectively sliding in a horizontal transverse direction respectively within the housings 64a and 64b. The locking cylinders are held partly outside their housing under the action of springs 65a and 65b respectively. Under the counter-jib 42, there is, projecting, an inverted U-shaped part 66, the two lateral faces of which are bevelled. Two holes 67a and 67b, intended to serve respectively as housing for the external part of each of the locking cylinders 63a and 63b, were made respectively on the two lateral faces of the part 66.

In the final alignment phase of the dart 41 and the jib foot 31, the end of the outer part of the two locking cylinders 63a and 63b comes into contact with the part 66. The bevelled shape of the lateral faces of this playing part the role of guide, the locking cylinders are gradually introduced by sliding within their respective housings 64a and 64b and the springs 65a and 65b are gradually compressed. The alignment phase continuing, the ends of the locking cylinders will be located respectively with the holes 67a and 67b.

The precise alignment of the cylinders 63a, 63b with the holes 67a, 67b is obtained by means of two stops 68a, placed respectively on either side of the part 66. In this particular position, under the action of the springs 65a and 65b , the locking cylinders 63a and 63b respectively engage in the two holes 67a and 67b, thus ensuring the locking in aligned position of the dart with the jib foot. The distributing boom can then operate in lifting mode.

The performance of the lifting device in the lifting mode is illustrated in Figure 7.

The inclination of the distributing arrow obtained during the alignment of the distributing arrow and corresponding to position E is 7 ° above the horizontal. A range of more than 24 meters corresponds to the maximum range that can be obtained with this hoist. The height under hook is more than 24 meters from the top of the pylon. At position F, a maximum tilt of the boom of nearly 80 ° is obtained. The minimum reach is then 6 meters and the hook height is almost 42 meters.

To return to articulated working mode, two electromagnetic devices 69a, respectively secured to the two parts 62a and 62b, are actuated in order to allow the total withdrawal of the two locking cylinders 63a and 63b from the holes 67a and 67b. The actuator control device (1) for jacks makes it possible to break the alignment of the dart with the jib foot.

To completely fold the lifting device, it is first necessary to place the distributor boom in the working position in articulated mode and then bring the end 46 of the boom 43 to position D corresponding to the minimum reach. . The arrowhead 43 is then housed between the two beams of the arrowhead 31.

The next step is to release the tie rods 25. The jib foot 31, framing the dart point 43, then tilts towards the front of the lifting machine and comes to rest along the upper pylon 22, like this is illustrated in Figure 2. Indeed, the joint 26, supporting the boom foot 31, is placed in front of the upper pylon. A joint 27, supporting the two punches 16, is placed at the rear of the upper pylon.

The folding of the pylon is illustrated in FIG. 3 using a succession of superimposed views. To clarify the drawing, the major part of the distributing boom in a folded and folded position on the upper pylon as described above has been removed in this figure.

As shown in FIGS. 2 and 3, the end of each of the punches 16, opposite to that carrying the pulleys 17, is mounted in articulation with a straightening sling 20, thus avoiding the tilting of the punches towards the rear of the machine, the sling being connected to a straightening strut 23. The top of the pylon is extended by two pieces 28 forming a stop for the two punches, thus avoiding their tilting towards the front of the lifting machine. Each of the beams of the boom foot 31 carries a return bridge 32 for the straightening of the boom. On each of these easels is a stop 33 pressing respectively on each of the punches, thus preventing the tilting of the jib foot 31 towards the rear of the lifting machine.

By actuating a double-acting cylinder 18 which rests on the pylon foot 21 and acts on a system of connecting rods 19, the pylon folds around a horizontal articulation 24 and tilts thanks to the presence of straightening struts 23. The straightening slings 20, each linked in articulation at the end of a punch 16, rotate these punches around the articulation 27.

At the end of the folding process, all the elements of the lifting machine are horizontal, the upper pylon 22 resting on the pylon foot 21 and supporting the dart 41 framed by the two beams of the jib foot 31 , the punches 16 and the straightening slings 20 being placed alongside these elements. This configuration is shown in Figure 5.

An additional advantage offered by the distributing boom whose boom foot is made up of two beams is obtained with a lifting device having a folding pylon. This saves space when the lifting gear is fully folded, thus allowing a wide variety of modes of transport.

The fact that the dart 41 can be housed between the beams 31a and 31b of the jib foot 31 makes it possible to obtain a significant gain in space in height. Thanks to the compactness of the hoist in the folded position, numerous transport possibilities are offered, none of which require the specific construction of a rolling chassis. Figures 6a to 6c illustrate some of these possibilities.

According to FIG. 6a, the folded lifting device is placed on a carriage 71 and its carrying frame 11 is attached to the rear of a tractor 72. According to FIG. 6b, the lifting device is placed on an articulated trailer 73 to a tractor 72.

According to FIG. 6c, the lifting device is placed in a container 74 known by the name of "marine container" and whose standard dimensions are 12040 millimeters for the length and 2450 millimeters for the height. Previously and thanks to the presence of a vertical articulation 47, the counter-dart 42 was folded back on itself, thus saving space this time in length. The container can then be transported in a conventional manner, for example on a trailer with a flat platform 75.

The lifting device has been described above with a carrying frame 11 resting on the ground. It is understood that it can also be mounted, whatever the type of pylon that composes it, on a rolling carrying chassis, possibly self-propelled.

Some of the advantages obtained by using a distributing boom whose boom foot has a slot allowing the housing of all or part of the dart have just been illustrated with a lifting machine whose pylon is foldable. However, the same versatility and similar performances of the distributing jib are also obtained when this folding pylon is replaced by a conventional tower or even by a telescopic pylon.

In a second embodiment of the lifting machine, particularly advantageous when the pylon is a conventional tower 29 as shown in FIG. 9, the jib foot 31 consists of a single beam in the form of a fork V- Φ

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The articulation between jib foot and dart can be achieved by means of numerous variants of the articulation system with connecting rods and jacks without departing from the scope of the invention. Figure 14a is a schematic representation in side view of this joint which can represent both the joint of Figure 10 as the joint of Figure 13a or the joint of Figure 13b with regard to the arrangement of the cylinder 3 and connecting rods 8 and 9. It will be noted in particular in this FIG. 14a that one end 10 of the connecting rod 8 is articulated on the counter-dart.

The articulation shown schematically in Figure 14b differs from the articulation shown in Figure 14a in that the connecting rod 8 is articulated slightly more forward, on the other side of the articulation axis 45, on the tip dart.

FIG. 14c shows a variant in which the connecting rod 8 is articulated at 10 at the level of the articulation axis 45. The free end of the jack rod is articulated at 15 on a median zone of the connecting rod 9 and not at the articulation 7 between the connecting rod 9 and the connecting rod 8.

Figure 14d shows an alternative embodiment of Figure 14c, where the rod 8 is articulated on the dart point.

Figure 14e shows another alternative embodiment in which the rod 8 is articulated much more forward 10 on the dart point; the entire connecting rods + actuator system is located below the articulation axis 45. The head of the actuator rod is articulated at 15 in a central region of the connecting rod 9, the jib foot has a recess ( not shown in the figure) to accommodate the connecting rod and cylinder when the dart folds against the boom foot.

In FIG. 14f, the connecting rod 8 is also articulated at 10 clearly in front of the dart point. In this alternatively, it is the middle part of the connecting rod 9 which is articulated at the jib foot, while the ends of the connecting rod 9 are articulated at 7 and 14 respectively at the connecting rod 8 and at the cylinder head.

FIG. 14g shows an articulation in which the actuator rod is articulated directly on the axis 45 between arrowhead and counter-dart, while the connecting rods 8 and 9 have a common articulation 7 not at the end of the cylinder rod, but on the cylinder, near the point of exit of the cylinder rod.

Note in the joints shown in Figures 14a, 14b and 14g, the presence of four axes of rotation / horizontal joint while the joints shown in Figures 14c, 14d, 14e and 14f have five axes of articulation.

It will also be noted that on all the articulations shown in FIGS. 13a, 13b, 14a to 14g, the articulation axis 45 is arranged so that the dart point can come back against the jib foot, subject, in as regards the joints shown in FIGS. 14e and 14g, of a corresponding recess in the jib foot or in the dart. Those skilled in the art will readily understand that all the joints shown in FIGS. 14a to 14g for the third embodiment are adaptable mutatis mutandis to the first two embodiments.

It will also be noted that in FIGS. 12a-14g, the third embodiment of the dart carries a lifting bridge 50 situated approximately at the base of the jib foot / dart joint. It goes without saying that the first and second embodiments of the lifting machine can also be provided with such an easel 50. 3 Vv F 0) tt îi ttl Pi Mi J 3 Ml SU J Ω H ¹ Λ TJ Mi p- SU 3 Pi Ml Φ t TJ Mi P. fi

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is ensured by the pivoting of the pivoting arm 114. The rotation of the pivoting arm 114 is controlled by two counterweight cables 115. One end of the counterweight cables 115 is fixed at a fixed point 122 of the platform. The two cables 115 pass through two pulleys 118 carried by the pivoting arm 114, over two return pulleys 117 fixed to the platform, then over two pulleys 122 carried on either side by the top of the punch 16. The cables 115 are fixed to the dart 41 at a point 116 located at the joint 45, in the area where this dart is reinforced. The cables 115 are therefore arranged on either side of the jib foot 31 and of the counter-dart 42.

FIG. 16 shows an embodiment of the invention which differs from the embodiment shown in FIG. 15 only in that the cables 115 are fixed at points 116 ′ of the jib foot 31, located near of the articulation 45 foot of arrow / dart. The boom foot is reinforced at this level.

The location of the fixing point 116 or 116 ′ in this zone close to the articulation, combined with the fact that each cable 115, passing over the pulley 118 is arranged in duplicate between the point 122 and the arm 114, makes it possible to servo the angle of inclination of the arm 114, between a substantially horizontal position and a substantially vertical position, to the angle of inclination of the jib foot, also between a substantially horizontal position and a substantially vertical position, and this without use additional motor winding or unwinding the cables 115.

FIG. 17 shows a particular embodiment of the pulleys 118 and their mounting on the arm 114. The pulleys 118 are carried by a pivoting pulley arm 119, mounted in rotation on the counterweight arm 114 by its end 123. L assembly formed by the pulley arm 119 and the pulleys 118 is extended by a second arm 124 on which is fixed a counterweight 120, which, by making the assembly formed by the pulley arm 119 and the pulleys 118 exerts a tension on the cables 115 and keeps them taut when the jib foot 31 is in a position close to the vertical.

An additional fixed counterweight 125 can be placed on or under the platform. The stroke of the counterweight 113 in the direction of the pylon 29 is limited by a stop cable 126, stretched in FIG. 17, not stretched in FIGS. 15 and 16.

The adjustment of the counterweights 113, 120 and 125, as well as the adjustment of the arms 114 and 119 makes it possible to balance the crane optimally, in the different working modes, lifting, tilting and articulated.

Claims

claims

1. Machine for lifting and handling loads with a hinged and lifting distributing jib, comprising a pylon (21, 22, 29), a jib foot (31, 31a, 31b) articulated in rotation at its first end (35) at the top of the pylon, a dart (41) articulated in rotation at the second end

(36, 37) of the jib foot, said dart comprising on either side of its articulation axis (45) at the jib foot respectively a dart point (43) and a counter-dart (42, 49, 49a, 49b), an arrow retaining assembly comprising at least one punch (16) and an arrow tie rod (25), and at least one double-acting articulation cylinder (3, 3a, 3b) connecting the foot of dart arrow, determining the angle between arrow foot and dart, characterized in that said second end of the arrow foot and the counter-dart have conjugate shapes allowing the dart point to come into position aligned with the foot arrow.

2. Machine according to claim 1, characterized in that the arrow rod (25) is connected to the dart tip (43) passing through at least one lifting bridge (50) integral with the dart.

3. Machine according to claim 2, characterized in that the lifting bridge (50) is arranged substantially at the junction between the counter-dart (42, 49, 49a, 49b) and the dart tip (43).

4. Machine according to one of claims 1 to 3, characterized in that the counter-dart (49, 49a, 49b) and the second end (37) of the jib foot have prismatic profiles and come into contact with one against each other when the boom foot and dart are aligned.

5. Machine according to one of claims 1 to 3, characterized in that the second end (36) of the foot arrow has the shape of a fork with two branches (31a, 31b) and the counter-dart (42) is housed in the space (34) between the two branches.

6. Machine according to one of claims 1 to 3, characterized in that the jib foot consists of two parallel beams (31a, 31b) and that the counter-dart (42) is received in one spacing (34 ) between the two beams.

7. Machine according to one of the preceding claims, characterized in that the jib foot (31) and the dart (41) are connected by two cylinders (3a, 3b) of identical articulation, mounted symmetrically with respect to the plane of vertical symmetry of the arrow.

8. Machine according to one of the preceding claims, characterized in that the or the cylinders (3, 3a, 3b) of articulation directly connect the jib foot to the dart.

9. Machine according to one of claims 1 to 7, characterized in that the or the articulation cylinders directly connect the boom foot and dart tip.

10. Machine according to one of claims 1 to 7, characterized in that each actuator (3, 3a, 3b) of articulation connects the jib foot (31) and the dart (41) by means of two connecting rods (8, 8a, 8b, 9, 9a, 9b).

11. Machine according to claim 10, characterized in that said connecting rods are articulated to one another and to the jack by the same axis of rotation (7).

12. Lifting device with distributing jib according to one of claims 5 to 7, characterized in that it comprises a locking device comprising, on the one hand, two parts (62a, 62b), integral with the jib foot ( 31) and arranged opposite each side of the slot (34), each said parts being equipped with a sliding locking cylinder (63a, 63b), and, on the other hand, a counterpart (66), integral with the jib (42) and having bevelled side faces each comprising a bore (67a, 67b), the assembly being arranged so that the cylinders (63a, 63b) can cooperate respectively with each of the holes during alignment of the dart with the jib foot.

13. Machine according to one of claims 1 to 12, in particular tower crane, characterized in that it comprises a mobile counterweight (113), the position of which is controlled by the angle of inclination of the jib foot ( 31).

14. Machine according to claim 13, characterized in that said mobile counterweight (113) is fixed to a first end of a pivoting counterweight arm (114), the second end (121) of which is articulated in rotation with the platform ( 112) of the machine, on the side opposite to the boom, and in that said pivoting counterweight arm (114) is connected (116, 116 ′) to the boom near the jib foot / dart joint by at at least one counterweight cable (115) passing over said punch (16).

15. The machine as claimed in claim 14, characterized in that a first end (116) of said counterweight cable (115) is fixed to the dart (41), in particular to the reinforced part of the dart / jib foot joint.

16. Machine according to one of claims 14 or 15, characterized in that the second end of said cable (115) of counterweight is fixed to the platform (112) and in that said cable (115) of counterweight passes over a pulley (118) carried by said pivoting counterweight arm (114).

17. Machine according to claim 16, characterized in that said pulley (118) is connected to said pivoting counterweight arm (114) by a pivoting pulley arm (119), articulated to said pivoting counterweight arm, and in that all formed by said pulley (118) and said pulley arm (119) includes weighting means (120) for tensioning said counterweight cable (115).

18. Machine according to one of claims 14 to 17, characterized in that it comprises two counterweight cables (115) passing on either side of the boom foot (31).