EP0873964B1 - Device for erecting the tower for a telescopic crane - Google Patents

Description

The present invention relates to self-erecting tower cranes with telescopic poles, foldable for transport on the road, and this invention relates more particularly to a mast lifting device for such a crane, that is, that is to say a device which allows the telescopic mast to be straightened, by moving it from a substantially horizontal transport position to a vertical working position, the lifting of the mast being accompanied by that of the boom of the crane, carried by the mast.

A self-erecting tower crane, with telescopic mast, usually comprises a fixed or rolling base frame supporting, by means of an orientation device, a rotating frame which itself supports the telescopic mast generally constituted two or three elements mounted sliding one into the other. The connecting means, provided between the rotating frame and the lower and outer mast member, are designed to allow the raising of the mast and, consequently, the training of the assembly consisting of the mast and the boom, this in a continuous movement.

• une liaison motorisée, par un treuil et un mouflage, entre le châssis tournant et le pied du mât,
• deux haubans avant articulés entre le châssis et le mât,
• deux haubans arrière aussi articulés entre le châssis et le mât.

A first known solution, applied to a telescopic mast crane in two or three elements, comprises:

• a motorized connection, by a winch and a halyard, between the rotating frame and the foot of the mast,
• two front stays articulated between the frame and the mast,
• two rear stays also articulated between the frame and the mast.

This articulated double link induces a lift kinematics which makes it possible to maintain the center of gravity of the moving parts as close as possible to the center of the lifting polygon. The front stays can be connected together, as well as the rear stays. These stays are connected to the lateral faces of the mast, or to the front of the mast.

Such a lifting device has a bulk width width, resulting from the lateral arrangement of the stays. It also has the particularity that the space between the ground surface and the lower part of the structure of the crane decreases during the lifting; this results in difficulties for the broaching and unplugging of the rear transport train of the crane, or difficulties in case of crowded construction site. The device still requires connecting pieces between the mast and the transport equipment, and it also requires separate drive means, on the one hand for lifting the mast and on the other hand for telescoping the mast. Finally, this known device has a small range of postage, for laying the front and rear supports of the base frame.

• un pied de mât assurant la liaison articulée entre la partie inférieure et extérieure du mât et le châssis tournant,
• deux haubans arrière articulés entre le châssis et le mât,
• une liaison motorisée, par un vérin, entre le pied de mât et le châssis tournant, assurant le dépliage du mât et le relevage de l'ensemble constitué par la mâture et la flèche, jusqu'à la position verticale.

Another known lifting device, applied to a two-part telescopic mast crane, comprises:

• a mast foot providing the articulated connection between the lower and outer part of the mast and the rotating frame,
• two rear stay cables articulated between the frame and the mast,
• a motorized connection, by a jack, between the mast foot and the rotating frame, ensuring the unfolding of the mast and the lifting of the assembly consisting of the mast and the arrow, to the vertical position.

In this embodiment, the volume and length of the mast foot make the free space between the ground and the weak mast foot, when the crane is in the transport position, hence the need for transport equipment lowers and attached very backward, which limit the rear clearance angle, causing difficulties access to construction sites. In addition, the efforts to be exercised during the lifting require a powerful motorization.

• FR 2464217 A : le relevage du mât est assuré par le système de télescopage, complété par un câble de relevage, et en utilisant un treuil.
• FR 2370674 A : le relevage du mât est là aussi assuré par son télescopage, en utilisant un vérin qui est le vérin de télescopage monté entre l'élément extérieur inférieur et l'élément intérieur supérieur du mât.
• EP 0132572 A : le relevage du mât est assuré par un treuil associé à un mouflage.

Other mast lifting devices, for tower cranes with telescopic mast, are known from documents FR 2464217 A, FR 2370674 A and EP 0132572 A, the structures and operations of these devices however remaining far from the object of the invention. present invention:

• FR 2464217 A: mast lifting is provided by the telescoping system, completed by a lifting cable, and using a winch.
• FR 2370674 A: raising the mast is also ensured by its telescoping, using a jack which is the telescoping jack mounted between the lower outer member and the upper inner member of the mast.
• EP 0132572 A: raising the mast is provided by a winch associated with a hauling.

In these three documents, the lower element of the telescopic mast is articulated directly on the rotating frame of the crane, contrary to the object of the present invention.

The present invention aims at eliminating the disadvantages of the devices described above, by providing a mast lifting device which is compact and simpler, and which facilitates and makes safer the operations of positioning and lifting the crane , as well as its transport.

• au moins un hauban avant, assurant une liaison articulée entre la partie avant du châssis tournant et l'arrière de l'élément inférieur et extérieur du mât télescopique, cet élément n'étant pas articulé directement sur le châssis tournant,
• au moins un hauban arrière, assurant une liaison articulée entre un point intermédiaire ou arrière du châssis tournant et l'arrière de l'élément inférieur et extérieur du mât télescopique,
• et un ensemble motorisé, comprenant au moins un vérin à double effet et un système de bielles, assurant une liaison entre le ou les haubans avant et l'élément inférieur et extérieur du mât télescopique, et commandant les mouvements relatifs de l'ensemble des éléments du dispositif de relevage.

To this end, the invention relates to a self-erecting tower crane and telescopic mast comprising a mast lifting device, the lifting device comprising:

• at least one front stay, providing an articulated connection between the front part of the rotating frame and the rear of the lower and outer element of the telescopic mast, this element not being articulated directly on the rotating frame,
• at least one rear stay, providing an articulated connection between an intermediate or rear point of the rotating frame and the rear of the lower and outer element of the telescopic mast,
• and a motorized assembly, comprising at least one double-acting cylinder and a connecting rod system, providing a connection between the front stay or cables and the lower and outer element of the telescopic mast, and controlling the relative movements of all the elements. of the lifting device.

According to a preferred embodiment of the invention, the mast lifting device comprises a single front seat with profiles symmetrical with respect to the vertical median plane of the rotating frame and the mast, two rear stays symmetrical to each other by relative to this median plane, a single jack located in said median plane and stitched by a first end at an intermediate point of the front stay, a transverse bar mounted at the other end of the jack, and two symmetrical pairs of lateral rods connected by trunnions respectively on both sides of the rudder bar, each pair of connecting rods comprising a smaller link rod articulated with the lower and outer member of the telescopic mast, and a longer connecting rod hinged with the front stay at a point near the articulation of the latter with the lower and outer element of the telescopic mast. Advantageously, the front stay is composed of two parallel beams, symmetrical with respect to the above-mentioned vertical median plane and rigidly connected to each other by a cross-member, to which is affixed the first end of the jack, which takes place between the two. beams. A such double but monobloc front stay, associated with a single jack, has the advantage of ensuring the stability of the assembly, even in the case of a load distributed asymmetrically with respect to the vertical median plane.

• La motorisation réalisée par l'ensemble à vérin et bielles procure une grande sûreté de mouvement, au cours de l'opération de relevage du mât ainsi qu'au cours de l'opération inverse d'abaissement du mât.
• Le vérin de l'ensemble motorisé de relevage est aussi utilisable comme moyen de motorisation du télescopage du mât, de sorte qu'il constitue un moyen de motorisation commun aux deux fonctions.
• Le positionnement convenable de l'attache du hauban avant sur l'élément de mât inférieur et extérieur permet de réduire les efforts de relevage et la puissance nécessaire pour la motorisation.
• Les haubans avant et arrière étant articulés à l'arrière de l'élément de mât inférieur et extérieur, et non pas sur les faces latérales de cet élément, l'encombrement en largeur du dispositif se trouve réduit.
• La faible dimension du hauban avant permet aussi l'utilisation de trains de transport standards, et d'augmenter l'angle de dégagement arrière pour faciliter les accès sur les chantiers.
• Le hauban avant peut servir lui-même d'élément de liaison entre la mâture et l'équipement de transport, d'où une simplification supplémentaire par suppression de pièces de liaison.
• Lors du relevage du mât, l'espace libre entre le sol et la partie inférieure du hauban avant et du mât voit sa hauteur augmenter, ce qui dégage la place nécessaire pour le brochage ou le débrochage du train de transport arrière.
• L'amplitude de mise à poste de la grue est augmentée.
• La liaison entre le mât relevé et le châssis tournant peut être rigidifiée, en position redressée de travail, en prévoyant une liaison non permanente du genre brochage, soit directement entre la partie inférieure du mât et la partie avant du châssis tournant, soit entre la partie inférieure du mât et un point intermédiaire de la longueur du hauban avant ; cette dernière solution offre en outre l'avantage d'un gain de hauteur pour la mâture.

Overall, the mast lifting device object of the invention has the following advantages (solving the problems encountered with the known solutions mentioned above):

• The motorization realized by the assembly with cylinder and connecting rods provides a great safety of movement, during the operation of raising of the mast as well as during the reverse operation of lowering of the mast.
• The cylinder of the motorized lifting assembly is also used as a means of motorization telescoping mast, so it is a means of motorization common to both functions.
• The proper positioning of the front stay attachment on the lower and outer mast member reduces the lifting forces and power required for the drive.
• The front and rear stays are hinged to the rear of the lower and outer mast member, and not on the side faces of this element, the overall width of the device is reduced.
• The small size of the front stay also allows the use of standard transport trains, and increase the rear clearance angle to facilitate access to the building sites.
• The front stay can serve itself as a link between the mast and the transport equipment, which simplifies the additional by removing connecting pieces.
• When raising the mast, the free space between the ground and the lower part of the front stay and the mast increases its height, which frees the necessary space for the broaching or unhitching of the rear transport train.
• The amplitude of stationing of the crane is increased.
• The connection between the mast raised and the rotating frame can be stiffened, in the upright working position, by providing a non-permanent connection of the kind broaching, either directly between the lower part of the mast and the front part of the rotating frame, or between the part lower mast and an intermediate point of the length of the front stay; this latter solution also offers the advantage of a height gain for the mast.

• Figure 1 est une vue de côté d'une grue pourvue du dispositif de relevage de mât conforme à la présente invention, en position de travail ;
• Figure 2 montre la même grue, vue de côté, en position repliée après mise à poste ;
• Figure 3 une vue de côté partielle de cette grue, en cours de relevage dans une position intermédiaire ;
• Figure 4 est une vue de face de l'ensemble motorisé de relevage.

The invention will be better understood from the description which follows, with reference to the appended schematic drawing showing, by way of example, an embodiment of this mast lifting device for telescopic tower crane:

• Figure 1 is a side view of a crane provided with the mast lifting device according to the present invention, in the working position;
• Figure 2 shows the same crane, seen from the side, in the folded position after posting;
• Figure 3 a partial side view of this crane, being raised in an intermediate position;
• Figure 4 is a front view of the motorized lift assembly.

The tower crane, shown schematically in FIG. 1, comprises, in a known manner, a fixed base frame 1 supporting, via a device 2, a rotating frame 3 which carries a counterweight at the rear 4. The rotating frame 3 supports, at the front, a telescopic mast 5 which consists of three elements, namely a lower and outer element 6, an intermediate element 7 and an upper and inner element 8, all of section for example square or polygonal. This crane is provided with a distributing arrow 9 with carriage 10, carried by the top of the upper element 8 of the telescopic mast 5, and held in a horizontal position by a rear retaining device 11 connected to the rear part of the rotating frame 3 .

A mast lifting device, generally designated by the reference 12, provides the connection between the rotating frame 3 and the lower and outer element 6 of the telescopic mast 5 (this element 6 is not articulated directly on the rotating frame 3), and allows the mast 5 to be brought into the vertical working position, starting from the horizontal position of the position shown in FIG. 2, and vice versa.

The lifting device 12 consists mainly of a front stay 13, two rear stays 14, a jack 15 and a system of rods 16 and 17.

The front stay 13 is articulated by a first end, about a horizontal axis 18, to the front part of the rotating frame 3. The other end of the front stay 13 is hinged to the lower and outer member 6 of the telescopic mast 5 along a horizontal axis 19 located at the rear of the mast element 6, more particularly outside the rear face 20 of this mast element 6. As shown in FIG. 4, the front stay 13 is composed of two parallel beams 21, symmetrical with respect to the vertical median plane P of the rotating frame 3 and the mast 5, the two beams 21 being secured to one another by a cross member 22 located at a short distance from the first end of the front stay 13.

The two rear shrouds 14 are parallel and symmetrical with respect to the vertical median plane P. Each rear shroud 14 is hinged at one end, along a horizontal axis 23, at an intermediate point of the rotating frame 3, relatively close to its rear portion. The other end of each rear stay 14 is articulated, along a horizontal axis 24, to the lower and outer part 6 of the telescopic mast 5. The hinge pin 24 is located outside the rear face 20 of this mast element 6, above the hinge axis 19 of the front stay 13 with the same mast element 6.

The jack 15, which is a double-acting hydraulic jack, is located in the vertical median plane P. The body 25 of the jack 15 is pinned at one end to the cross member 22 of the front stay 13, so that the jack 15 takes place between the two beams 21 of the front stay 13. The rod 26 of the jack 15 carries, at its outer end, a transverse beam 27, having a horizontal pin 28 at each end.

The linkage system comprises two pairs of rods 16,17, symmetrical with respect to the vertical median plane P, the two connecting rods 16 and 17 of each pair being of unequal lengths. The rod 16 of smaller length is hinged, at one of its ends, on the trunnion 28 and, at its other end, along a horizontal axis 29, on the corresponding side of the lower and outer element 6 of the telescopic mast 5; the hinge axis 29 of the connecting rod 16 is located at an intermediate level between the respective hinge pins 19 and 24 of the front stay 13 and the rear stays 14 with the mast element 6. The connecting rod 17 of larger length is articulated, by one of its ends, on the pin 28 and, at its other end, along an axis horizontal 30, at the front stay 13; the hinge axis 30 of the connecting rod 17 is relatively close to the hinge axis 19 of the front stay 13 with the mast element 6.

The actuation of the jack 15 in the direction of the output of its rod 26 controls the lifting of the telescopic mast 5, from its horizontal position of setting (FIG. 2) to its vertical working position (FIG. a continuous deformation movement of the quadrilateral defined by the rotating frame 3, the front stay 13, the rear stays 14 and the mast member 6, the movement being effected through intermediate positions, one of which is shown on the 3. When the telescopic mast 5 is fully straightened, the lower end of its lower and outer element 6 is secured, by a broach 31, with the front stay 13.

The lowering of the telescopic mast 5 and its horizontal setting, for the purpose of transporting the crane, is carried out by actuating the jack 15 in the opposite direction of the lifting, that is to say in the direction of the retraction of its rod 26, after having disengaged the lower part of the mast 5 of the front stay 13 by removing the broach 31.

The cylinder 15, providing the motorization of the lifting of the telescopic mast 5, can also be used for the motorization of the telescoping function of this mast 5. In this other use of the cylinder 15, the spreader 27 mounted at the end of the rod 26 of the jack 15 and connected to the connecting rods 16 and 17 constitutes a fixed point, while the body 25 of this jack 15, desolisarisé of the crosspiece 22 and connected to a muffle 32, constitutes the mobile part of a haulage whose second muffle 33 is secured to the base of the front stay 13 (see Figure 4).

• par des modifications de structure, telles que le remplacement du vérin unique 15 par deux vérins parallèles reliés par un palonnier d'équilibrage, le hauban avant 13 restant unique, ou par deux vérins associés respectivement à deux haubans avant, avec adjonction d'un répartiteur hydraulique d'efforts ;
• en prévoyant un brochage 31 de la partie inférieure du mât 5 non pas sur le hauban avant 13, mais directement sur la partie avant du châssis tournant 3 ;
• en destinant le même dispositif de relevage à une grue dont le mât télescopique ne comporterait pas trois éléments, mais seulement deux éléments de mât ou, au contraire, plus de trois éléments.

One would not depart from the scope of the invention as described in the claims:

• by structural modifications, such as the replacement of the single cylinder 15 by two parallel cylinders connected by a balancing beam, the front stay 13 remaining single, or by two cylinders respectively associated with two front stays, with the addition of a splitter hydraulic efforts;
• by providing a pin 31 of the lower part of the mast 5 not on the front stay 13, but directly on the front part of the rotating frame 3;
• by targeting the same lifting device to a crane whose telescopic mast does not include three elements, but only two mast elements or, on the contrary, more than three elements.

Claims (6)

1. An automatic-assembly tower crane with a telescopic tower, said crane comprising a tower raising device (12) and a fixed or movable base frame (1) which supports, via an orientation device (2), a rotating frame (3) which supports the telescopic tower (5), characterised in that the raising device (12) comprises:

   - at least one front stay (13) which forms an articulated joint between the front part of the rotating frame (3) and the rear (20) of the lower external element (6) of the telescopic tower (5), said element (6) not being articulated directly to the rotating frame (3),

   - at least one rear stay (14) which forms an articulated joint between an intermediate or rear point (23) of the rotating frame (3) and the rear (20) of the lower external element (6) of the telescopic tower (5),

   - and a motorised assembly comprising at least one double-acting jack (15) and a system of connecting rods (16, 17), forming a joint between the front stay or stays (13) and the lower external element (6) of the telescopic mast (5), and controlling the relative movements of the system of elements of the raising device (12).
2. A crane according to claim 1, characterised in that the tower raising device comprises a single front stay (13) with symmetrical profiles with respect to the central vertical plane (P) of the rotating frame (3) and of the tower (5), two rear stays (14) which are symmetrical to each other with respect to said central plane (P), a single jack (15) which is situated in said central plane (P) and which is pin-jointed at a first end to an intermediate point (22) of the front stay (13), a transverse lifting beam (27) mounted at the other end of the jack (15), and two symmetrical pairs of lateral connecting rods (16, 17) connected by journals (28) to the two respective sides of the lifting beam (27), each pair of connecting rods comprising a connecting rod of lesser length (16) articulated (at 29) to the lower external element (6) of the telescopic tower (5), and a connecting rod of greater length (17) articulated to the front stay (13) at a point (30) situated near the articulated joint (19) of the front stay to the lower external element (6) of the telescopic tower (5).
3. A crane according to claim 2, characterised in that the front stay (13) is composed of two parallel beams (21) which are symmetrical with respect to the aforementioned central vertical plane (P) and which are rigidly attached to each other by a crossbeam (22), to which is coupled the first end of the jack (15) which is situated between the two beams (21).
4. A crane according to any one of claims 1 to 3, characterised in that the jack (15) of the motorised raising assembly is provided so that it can also be used as a means of motorising the telescopic movements of the tower (5).
5. A crane according to any one of claims 1 to 4, characterised in that a non-permanent connection, of a pin-joint type (31), is provided between the lower part of the telescopic tower (5) in its erected operating position, and the front part of the rotating frame (3).
6. A crane according to any one of claims 1 to 4, characterised in that a non-permanent connection, of a pin-joint type (31), is provided between the lower part of the telescopic tower (5) in its erected operating position, and an intermediate point along the length of the front stay (13).