EP1418151B1 - Chassis with devices for articulations for outriggers - Google Patents

Description

The present invention relates to a chassis comprising support arms on the ground, each articulated to the chassis by a hinge device, for a machine, in particular a hoist and, more particularly, a tower crane.

In the field of tower cranes, there are among others cranes which rest on the ground via a fixed frame. For this type of crane, the most common ground support system consists of four support arms, articulated to the frame. Each arm, made of sheet metal and having a box structure, has at its free end an adjustable foot support on the ground. The other end of this support arm is articulated to the frame about a vertical axis, which allows the folding of the arm against the frame for the transport of the crane. The articulating device of the arm on the chassis is of the chapetenon type, with a simple axis, the clevis being constituted by an upper plate of the frame and a bottom plate of the frame (in a corner zone of this frame), with a vertical clearance for the assembly of the arm with the frame, and the pivoting of said arm. The game must take into account the superposition tolerances of the sheets that constitute the box structure of the arm, and also the realization of the frame. Thus this game can be relatively important and reach values of the order of 15 mm.

The correct support of the crane in working position, on the four arms deployed, is ensured by a perfect contact between the upper bearing surface of the arms, on the one hand, and the lower bearing surface of the upper plate chassis, on the other hand. The aforementioned game is then located at the lower part of the arms and the frame.

Conversely, during the transport of the crane, each arm is supported on the lower plate of the frame, because of the weight of this arm. The game is located at the top of the arms and the chassis.

When placing the crane on the ground, the arms are supported successively on the ground by their respective feet. When placing an arm on the ground, the frame lowers until it comes into contact, by the support surface of its upper sheet, with the upper bearing surface of the arm concerned. At this moment, the frame slides downwards, along the hinge axis of the arm to the frame.

The disadvantage of such a hinge device, particularly in the case of support arms of great length and relatively high height low at the joint, is a serious risk of jamming of the arm on the axis of articulation, at the time of placing the crane on the ground. Indeed, the ratio between the length and the height of the arm determines a coefficient of friction, which must not exceed a certain value for the arm to freely slide along its axis of articulation to the frame. As a result of the jamming thus observed, and given the game previously discussed, the upper support of the arm against the bearing surface of the upper plate of the frame does not take place, and the correct transmission of the frame forces to the arms is not carried out, which can deteriorate the chassis and, consequently, unbalance the crane or cause jolts when unhooking the arm.

The document FR-A-673782 discloses a similar ground support system for a transport vehicle of a hoisting apparatus such as a crane, this vehicle comprising a chassis provided with four support arms on the ground, each of the arms support is articulated to the frame by a hinge device which comprises a substantially vertical axis of articulation, extending between a lower sheet or beam of the frame and a sheet or upper beam of the frame, the hinge axis passing through and from one side, on its height, the region of one end of the support arm. More particularly, this hinge pin passes through bores in the lower and upper plates of the frame, and in the region of the end of the support arm. Locking means in rotation of the hinge pin, with locking key, are provided in the upper part of the hinge axis, at the upper plate of the frame. This document serves as a basis for the preamble of claim 1.

The present invention aims to avoid the aforementioned drawbacks by providing for the support arms an improved articulation device, which guarantees in the working position a certain and permanent support of said arms against the frame, so as to ensure a perfect transmission of efforts between the arms and the chassis, thanks to a "recovery" of assembly games.

• un axe d'articulation sensiblement vertical, s'étendant entre une tôle inférieure et une tôle supérieure du châssis, et traversant de part en part, sur sa hauteur, la région d'une extrémité du bras d'appui ;
• dans les tôles inférieure et supérieure du châssis, et dans la région de l'extrémité du bras d'appui, des alésages traversés par l'axe d'articulation ;
• dans la partie supérieure de l'axe d'articulation, et au niveau de la tôle supérieure du châssis, des moyens de blocage en rotation de l'axe d'articulation, relativement à cette tôle supérieure ;

ce châssis étant caractérisé en ce que :

• l'alésage de la tôle inférieure du châssis possède un diamètre supérieur au diamètre des alésages du bras et de la tôle supérieure du châssis ;
• dans la partie inférieure de l'axe d'articulation, un épaulement annulaire délimite une tête inférieure de cet axe de diamètre correspondant à l'alésage de la tôle inférieure du châssis, tandis que le diamètre dudit axe au-dessus de son épaulement correspond aux alésages du bras et de la tôle supérieure du châssis ;
• dans la partie supérieure de l'axe d'articulation, et au niveau de la tôle supérieure du châssis, sont prévus des moyens de positionnement et de traction vers le haut de l'axe d'articulation, relativement à cette tôle supérieure ;

de telle sorte qu'en exerçant une traction de l'axe d'articulation vers le haut, cet axe entraîne vers le haut le bras par l'intermédiaire de son épaulement, et amène ainsi la surface supérieure du bras contre la surface inférieure de la tôle supérieure du châssis.For this purpose, the subject of the invention is a chassis comprising support arms on the ground, each articulated to the chassis by a hinge device, for a machine, in particular a lifting machine and, more particularly, a crane. in turn, the articulation device comprising, for each of the support arms:

• a substantially vertical axis of articulation, extending between a lower plate and an upper plate of the frame, and passing right through, over its height, the region of one end of the support arm;
• in the lower and upper plates of the frame, and in the region of the end of the support arm, bores traversed by the hinge pin;
• in the upper part of the hinge pin, and at the level of the upper plate of the frame, means for locking in rotation of the hinge pin relative to this upper sheet;

this chassis being characterized in that:

• the bore of the bottom plate of the frame has a diameter greater than the diameter of the bores of the arm and the upper plate of the frame;
• in the lower part of the hinge axis, an annular shoulder delimits a lower head of this axis of diameter corresponding to the bore of the lower plate of the frame, while the diameter of said axis above its shoulder corresponds to bores of the arm and the upper plate of the chassis;
• in the upper part of the hinge pin, and at the level of the upper plate of the frame, there are provided means for positioning and pulling upwards of the hinge axis relative to this upper sheet;

such that by pulling the hinge axis upwards, this axis drives the arm upwardly through its shoulder, and thus brings the upper surface of the arm against the lower surface of the upper plate of the chassis.

• d'une part, en regard de l'extrémité supérieure de l'axe, au moins un trou prévu pour recevoir un organe de positionnement et de traction de cet axe ;
• d'autre part, de manière excentrée par rapport à l'extrémité supérieure de l'axe d'articulation, au moins un autre trou prévu pour recevoir un pion de blocage en rotation de cet axe.

According to a preferred embodiment of the invention, the means for positioning and locking in rotation of the hinge pin comprise a positioning plate and blocking the axis, said plate taking place horizontally above the upper plate of the frame, and this plate comprising:

• on the one hand, facing the upper end of the axis, at least one hole provided to receive a positioning member and traction of this axis;
• on the other hand, eccentrically relative to the upper end of the hinge pin, at least one other hole provided for receiving a locking pin in rotation of this axis.

According to a particular embodiment, the positioning and traction means of the hinge pin comprise at least one traction screw, intended to be introduced through the corresponding hole of the locking positioning plate, and at least one tapped hole formed in the upper end of the hinge axis, the or each pulling screw being clamped in the corresponding tapped hole of the axis.

Thus, the idea underlying the invention is to achieve the articulation of each support arm on the frame, no longer by a single axis, but by means of a stepped axis, which can be pulled to the top, particularly by means of pulling screws, to bring the upper part of the arm and the upper plate of the frame.

• Les bras d'appui étant maintenus en permanence en position d'appui, au moyen de l'axe, comme il vient d'être indiqué, on supprime le mouvement de coulissement relatif du bras et de l'axe au moment de la mise en appui de la grue sur le sol, et ainsi on élimine tout risque de coincement du bras sur l'axe.
• En conséquence, il est garanti une surface d'appui maximale entre chaque bras et le châssis, ce qui assure une parfaite transmission des efforts entre le châssis et les bras d'appui, donc entre la grue et le sol.
• Par ailleurs, la mobilité verticale de l'axe d'articulation, combinée avec les moyens de traction de cet axe vers le haut, permet une "récupération" des jeux importants de construction et d'assemblage, tant du châssis que des bras.
• Enfin, le dispositif d'articulation objet de l'invention reste de structure simple et économique, puisqu'il utilise des composants courants tels que plaque, axe, vis et pion, en nombre très limité.

In this way, the articulated support arms are permanently maintained in their high support position under the upper plate of the frame, which is their working position, which provides the following advantages:

• The support arms being permanently maintained in the support position, by means of the axis, as just indicated, the relative sliding movement of the arm and the axis is eliminated at the moment of setting. crane support on the ground, and thus eliminates any risk of jamming of the arm on the axis.
• As a result, it ensures a maximum support surface between each arm and the frame, which ensures a perfect transmission of forces between the frame and the support arms, so between the crane and the ground.
• Furthermore, the vertical mobility of the hinge pin, combined with the traction means of this axis upwards, allows a "recovery" of important games of construction and assembly, both the chassis and arms.
• Finally, the hinge device object of the invention remains simple and economical structure, since it uses common components such as plate, axis, screw and pin, in very limited numbers.

• Figure 1 est une vue de côté d'une grue à tour dont le châssis fixe est conforme à la présente invention ;
• Figure 2 est une vue d'ensemble, en perspective, du châssis fixe de la grue de la figure 1, avec ses bras d'appui déployés ;
• Figure 3 est une vue en coupe du dispositif d'articulation d'un bras d'appui, suivant III-III de la figure 2 ;
• Figure 4 est une vue de dessus de ce dispositif d'articulation.

The invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of example, an embodiment of this frame with support arm on the ground:

• Figure 1 is a side view of a tower crane whose fixed frame is in accordance with the present invention;
• Figure 2 is an overall view, in perspective, of the fixed frame of the crane of Figure 1, with its support arms deployed;
• Figure 3 is a sectional view of the articulation device of a support arm, according to III-III of Figure 2;
• Figure 4 is a top view of this hinge device.

Figure 1 shows a collapsible tower crane, which generally known comprises: a fixed frame 2 bearing on the ground 3; a rotating frame 4 mounted on the fixed frame 2 by means of an orientation device 5; a mast 6 articulated by its lower part on the rotating frame 4; a dispensing boom 7 hinged to the top of the mast 6; a retainer 8 of the boom 7.

The fixed frame 2, shown more particularly in Figure 2, comprises four support arms 9, deployable cross for the working position of the crane, and foldable against the frame 2 for transporting the crane. Each support arm 9, made of sheet metal, forms a kind of box beam, one end of which is connected to an angle of the fixed frame 2 by a hinge device 10, and the other end of which carries an adjustable foot 11. ground support.

The invention is more particularly concerned with the articulation device 10, shown in detail in FIGS. 3 and 4.

The fixed frame 2 comprises a lower horizontal plate 12 and an upper horizontal plate 13, of the same contour. These two superimposed plates 12 and 13 form four clevis configurations, on which the rear ends of the four support arms 9, respectively engaged between the lower plate 12 and the upper plate 13, are articulated respectively about vertical axes 14.

To receive a vertical axis 14, the lower plate 12 of the frame 2 comprises, in each screed portion, a bore 15 of diameter D. The upper plate 13 of the frame 2 comprises, coaxially with this bore 15, another bore 16 more small diameter d.

In the lower and upper plates of the rear end of the support arm 9, there are provided respective bores 17 and 18, coaxial and of the same diameter d, equal to that of the bore 16 of the upper plate 13 of the frame 2 .

In its portion comprising the bore 15, the bottom plate 12 of the frame 2 is doubled by a reinforcing sheet 19, provided with a bore of the same diameter D. Similarly, there is provided a reinforcing sheet 20 integral with the upper sheet 13 of frame 2, in the region of its bore 16, the reinforcing sheet being provided with a bore of the same diameter d.

The hinge pin 14, of generally cylindrical shape, has in its lower portion an annular shoulder 21, which delimits a lower head 22 of this axis 14 of diameter D corresponding to the diameter of the bore 15 of the lower plate 12 of the chassis 2. Above the shoulder 21, and up to the upper end 23 of the hinge axis 14, the diameter d of this axis 14 is constant, and corresponds to the diameter of the bores 17 and 18 of the arm 9 and the bore 16 of the upper plate 13 of the frame 2.

At the upper end 23 of the hinge pin 14 are formed, in diametrically opposite positions, two threaded holes 25 drilled vertically.

The hinge device 10 further comprises a positioning and locking plate 26 of the axis 14, the plate 26 having a disc shape extended by a radial lug. In the plate 26 are formed two holes 27 whose spacing is equal to that of the two tapped holes 25 of the hinge pin 14. In the mounted position of the hinge device 10, the positioning and locking plate 26 takes support on the reinforcement plate 20 integral with the upper plate 13 of the frame 2. Two tensioning screws 28 with brake are engaged from above through the respective holes 27 of the plate 26, and are respectively clamped in the two threaded holes 25 of the axis 14.

In the radial lug of the plate 26 is formed another hole 29, which will thus be offset laterally with respect to the axis of articulation 14. This other hole 29 receives a pin 30 for locking in rotation, also introduced into corresponding holes of the upper plate 13 and its reinforcing plate 20.

The operation and use of the articulation device 10, previously described, are as follows:

When assembling a support arm 9 with the fixed frame 2 of the tower crane, the arm 9 is engaged in one of the clevis portions of this frame 2, and is positioned so that that its bores 17 and 18 are aligned with the corresponding bores 15 and 16 of the frame 2.

The hinge axis 14 is introduced through the bore 15 of the bottom plate 12 of the frame 2, and successively engaged in the other bores 17 and 18 and finally 16, until its annular shoulder 21 comes to bear under the arm 9. The lower head 22 of the shaft 14 is then housed in the bore 15 of corresponding diameter D of the bottom plate 12 of the frame 2, while the upper end 23 of the shaft 14 has reached the level of the upper plate 13 and its reinforcing plate 20.

Then, the locking pin 30 of the positioning plate 26 is put in place, as well as this plate 26 itself, which thus bears on the reinforcing plate 20. Finally, the traction screws 28 are placed in position and tightened in the corresponding threaded holes 25. The hinge axis 14 is thus pulled upward, this pulling action being symbolized by an arrow T in FIG. 3. The axis 14 carries with it upwardly the arm 9, via its shoulder. 21. The arm 9 is thus brought closer to the upper plate 13 of the frame 2, the upper surface 31 of the arm 9 being brought against the lower surface 32 of the upper plate 13. However, the tightening of the traction screws 28 is not continued until the arm 9 is locked, because it must be ensured that this arm 9 remains free to rotate, to be deployed or retracted.

Each support arm 9 thus has, finally, negligible vertical clearance, which guarantees a permanent position of support on the sheet metal upper 13 of the fixed frame 2 of the crane, for work, and therefore a perfect transmission of forces between the frame 2 and the support arms 9, and therefore between the structure of the crane and the ground 3.

In addition, the reinforcing plates 19 and 20 increase the matting range of the hinge pin 14, in its lower and upper parts, and the reinforcing plate 20 provides a stiffening of the upper plate 13 of the frame 2, which is subjected to a bending moment during work.

The invention has been described above in the context of its application to a tower crane, with fixed frame 2 with articulated arms 9 of monobloc structure. This invention is also applicable in the case of telescopic arms, in which case the device concerned is used for articulated mounting of the outer member of each telescopic arm.

The same articulation device also applies to all lifting gear or similar devices, provided with support arms on the ground for their stabilization in the working position, for example: mobile cranes, nacelles for personnel intervention at height, truck mounted cranes.

• en modifiant le nombre des vis de traction, le recours à une ou plusieurs vis étant possible ;
• en remplaçant ces vis de traction par tous organes de traction équivalents, tels que goujons, ou axes filetés avec écrou... ;
• en modifiant les formes de détail du châssis et des bras ;
• en destinant le dispositif à des grues de configuration différente, ou à d'autres types d'engins de levage, comme déjà indiqué plus haut.

In addition, it is not departing from the scope of the present invention, as defined in the appended claims:

• by modifying the number of the traction screws, the use of one or more screws being possible;
• replacing these tensioning screws with all equivalent tensioning devices, such as studs, or threaded pins with nuts ...;
• modifying the details of the chassis and arms;
• by targeting the device to cranes of different configuration, or to other types of lifting gear, as already indicated above.

Claims (4)

1. Chassis (2) comprising arms bearing on the ground (9), each articulated to the chassis (2) by an articulation device (10), for a machine, in particular for a lifting machine and even more particularly a tower crane, the articulation device (10) comprising, for each of the bearing arms (9):

   - a substantially vertical articulation shaft (14) extending between a bottom metal sheet (12) and a top metal sheet (13) of the chassis (2), and passing right through, over its height, the region of one end of the bearing arm (9);

   - in the bottom (12) and the top (13) metal sheets of the chassis (2), and in the region of the end of the bearing arm (9), bores (15, 16, 17, 18) through which the articulation shaft (14) passes;

   - in the top part (23) of the articulation shaft (14), and level with the top metal sheet (13) of the chassis (2), means (29, 30) of locking the articulation shaft (14) with respect to rotation, relative to this top metal sheet (13);

   characterised in that:

   - the bore (15) in the bottom metal sheet (12) of the chassis (2) has a diameter (D) greater than the diameters (d) of the bores (16, 17, 18) in the arm (9) and in the top metal sheet (13) of the chassis (2);

   - in the bottom part of the articulation shaft (14), an annular shoulder (21) delimits a bottom head (22) of this shaft (14) with a diameter (D) corresponding to the bore (15) in the bottom metal sheet (12) of the chassis (2), whilst the diameter (d) of the said shaft (14) above its shoulder (21) corresponds to the bores (16, 17, 18) in the arm (9) and in the top metal sheet (13) of the chassis (2);

   - in the top part (23) of the articulation shaft (14), level with the top metal sheet (13) of the chassis (2), there are provided means (25 to 28) of positioning and upward traction of the articulation shaft (14) relative to this top metal sheet (13);

   so that, by exerting an upward traction (T) on the articulation shaft (14), this shaft (14) drives the arm (9) upwards by means of its shoulder (21) and thus brings the top surface (31) of the arm (9) against the bottom surface (32) of the top metal sheet (13) of the chassis (2).
2. Chassis with bearing arms according to claim 1, characterised in that the means of positioning and rotational locking of the articulation shaft (14) comprise a positioning and locking plate (26) for the shaft (14), the said plate (26) fitting horizontally above the top metal sheet (13) of the chassis (2), and this plate (26) comprising:

   - on the one hand, opposite the top end (23) of the shaft (14), at least one hole (27) designed to receive a positioning and traction member (28) for this shaft (14);

   - on the other hand, eccentrically with respect to the top end of the articulation shaft (14), at least one other hole (29) designed to receive a pin (30) for locking this shaft (14) in rotation.
3. Chassis with bearing arms according to claim 2, characterised in that the positioning and traction means for the articulation shaft (14) comprise at least one traction screw (28), designed so as to be introduced through the corresponding hole (27) in the positioning and locking plate (26), and at least one threaded hole (25) provided in the top end (23) of the articulation shaft (14), the or each traction screw (28) being tightened in the corresponding threaded hole (25) in the shaft (14).
4. Chassis with bearing arms according to claims 2 or 3, characterised in that the positioning and locking plate (26) bears on a reinforcement metal sheet (20), fixed to the top metal sheet (13) of the chassis (2) in the region where the articulation shaft (14) passes through it.

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