EP0855361B1 - Telescopic mast for a tower crane - Google Patents

Description

The present invention relates to cranes with tower, and more particularly to a mast structure telescopic type for tower crane.

In the field of foldable tower cranes in sight of their transport, one distinguishes in particular the mast cranes foldable into several parts, and mast cranes telescopic. The invention relates to mast cranes telescopic, whose mast consists of two or three mast elements, or even more numerous elements, mounted sliding inside each other so that form a telescopic, extendable structure or retractable vertically.

The elements of a telescopic crane mast turn must ensure the transmission of forces during of the crane work, as well as the continuity of the transmission of forces during telescoping; these latest efforts include normal efforts, shear forces, bending moments and moments of torsion. Guidance and centering of the mast elements with respect to the others, as well as the locking of the mast elements with each other in the working position.

Traditionally, the mast elements of cranes in turn are made of wire mesh. Recently Telescopic masts also appeared, the elements have a tubular or box configuration, with solid side faces. We know, in particular, telescopic masts whose elements consist of horizontal section boxes square or rectangular, so with four side faces, the mast elements being guided relative to the others by means of skates or rollers.

We also know, for example by the US patent N ° 4459786, composite telescopic crane jibs of box elements, of polygonal section. Such a arrow is mechanically comparable to a beam telescopic recessed at its base, which is subjected to significant bending efforts and efforts to weak compression. On the contrary, a crane mast to tower, of the kind here concerned, is comparable to a beam telescopic recessed at its base and subjected to forces low bending and compressive forces significant, as well as significant torsional forces. In addition, a telescopic crane boom can be telescoped in charge, when in use, while a mast crane is only telescoped when the crane is assembled, without charge. So the problems posed by an arrow telescopic, which by the way does not belong to a crane with turn, are not those encountered with a mast telescopic, and in particular it arises, in the case of the mast, the specific problem of the recovery of torsional and compressive forces.

Various telescopic mast structures, not applied to tower cranes, are also known. Through example, French patent application N ° 2404754 concerns a tool holder or some kind of antenna telescopic, with only two parts telescoping. Such a structure can be compared to a beam embedded at its base and subjected to stresses significant bending, due to wind, and to low compression, since it is not intended for lifting of loads. This document can therefore be compared to previous, so it doesn't solve the problems specific to the present invention. Note also that the telescopic structure of French document N ° 2404754 has tubular elements of horizontal section circular, with no relative blocking in rotation, and is therefore not suitable for taking up significant torsional forces applied to the masts of tower cranes. Finally, the particular technical solution of the the aforementioned French document is obviously not applicable to a mast comprising more than two elements telescoping.

The present invention aims to improve the telescopic masts for a tower crane composed of mast elements in box, by providing a mast whose elements have an optimized section, so as to improve it mechanical resistance, in particular by reducing the setting in the wind, while ensuring good guidance of the elements of mast relative to each other, and especially by being capable of resisting torsional forces and compression to which such a structure is subjected, what whatever the number of its elements.

To this end, the invention has for object a telescopic mast for crane, composed of several mast elements slidably mounted one at a time the interior of the others and each having a structure in a box, this mast being characterized in that the box mast elements each have a section polygonal in shape with more than four sides, determined by lateral faces parallel and / or perpendicular to the front-rear direction of the crane, and side faces intermediate, oblique to this direction front-rear, said mast comprising means for guiding the mast elements relative to each other others, located on oblique lateral faces of these mast elements, and automatic locking means said mast elements with each other, in predetermined relative positions, which are arranged on lateral faces parallel and / or perpendicular to the front-rear direction of the crane.

In a preferred embodiment of the telescopic mast object of the invention, the elements of box mast each has a shaped section dodecagonal, determined by two opposite side faces parallel to the front-rear direction of the crane, a front side face and rear side face perpendicular to the front-rear direction of the crane, and eight oblique faces, divided into four pairs of adjacent oblique faces connecting, two by two, the faces previous side.

The polygonal section with more than four sides, in particular with twelve sides, thus proposed, constitutes a ideal compromise between square or rectangular section, ideal for guidance, and the circular section, ideal to withstand the forces due to the wind. In particular, the dodecagonal section is close to the section of optimal resistance which is that of a section tube round, and a mast which has such a section dodecagonal has, with identical resistance, a reduced size and weight compared to a mast square or rectangular section. Resistance to face warping is also improved, which removes the need for stiffeners. In comparison with mast elements formed by section tubes round, the mast structure object of the invention also has the advantage of easier manufacturing and more economical, either by cold bending a sheet, or by assembling sheets corresponding to the various faces. The sufficiently numerous side faces of the elements mast of polygonal section allow to dissociate well the guide means and the locking means. In in particular, the location of the guide means on the oblique faces provides self-centered guidance in the plane vertical center of the crane, with clearances, in preventing any rotation of an interior mast element by relative to an external mast element, while the mast interior is subjected to sharp forces.

• quatre patins de guidage situés à la base de l'élément de mât intérieur, et fixés extérieurement sur les faces obliques de cet élément adjacentes aux faces avant et arrière, et
• quatre autres patins de guidage situés au sommet de l'élément de mât extérieur, et fixés intérieurement sur les faces correspondantes de cet élément, c'est-à-dire ses faces obliques adjacentes aux faces avant et arrière.

In an advantageous embodiment, applicable to mast elements of dodecagonal section as defined above, the guide means comprise, in combination, for an inner mast element and an associated external mast element:

• four guide shoes located at the base of the inner mast element, and fixed externally on the oblique faces of this element adjacent to the front and rear faces, and
• four other guide pads located at the top of the external mast element, and fixed internally on the corresponding faces of this element, that is to say its oblique faces adjacent to the front and rear faces.

Preferably, all of these guide shoes are constituted by a sliding plate covering substantially the entire width of the oblique face corresponding, to reduce the contact pressure to a minimum value, the plate being covered with a synthetic coating reducing the coefficient of friction, and also removing the need for a lubrication.

Thanks to the arrangement of the guide shoes, the side games are canceled by the contact of the skates on the corresponding oblique faces, and the front clearances and rear are caught by "wedge phenomenon", which allows self-centered guidance.

• un ensemble de blocage supérieur, composé de deux patins latéraux d'encastrement disposés à l'extérieur des faces latérales, parallèles à la direction avant-arrière de la grue, de l'élément de mât intérieur, et de deux logements d'encastrement disposés à l'intérieur des faces correspondantes de l'élément de mât extérieur, au sommet de ce dernier,
• un ensemble de blocage inférieur, composé de deux autres patins latéraux d'encastrement disposés à l'extérieur des faces latérales, parallèles à la direction avant-arrière de la grue, de l'élément de mât intérieur, à la base de ce dernier, et de deux logements d'encastrement disposés à l'intérieur des faces correspondantes de l'élément extérieur,

les patins d'encastrement étant pourvus de rampes d'engagement et de dégagement,

• et deux verrous symétriques rabattables, articulés au sommet de l'élément de mât extérieur et commandés automatiquement lors du télescopage des éléments de mât, les verrous coopérant avec les patins et les logements d'encastrement de l'ensemble de blocage supérieur, en venant s'engager, une fois rabattus, respectivement entre les deux patins et les logements correspondants.

As for the means for automatic locking of the mast elements with each other, these advantageously comprise, in combination, for an inner mast element and an associated outer mast element:

• an upper locking assembly, composed of two lateral mounting pads arranged outside the side faces, parallel to the front-rear direction of the crane, of the inner mast element, and two mounting housings arranged inside the corresponding faces of the external mast element, at the top of the latter,
• a lower blocking assembly, composed of two other lateral mounting pads arranged outside the lateral faces, parallel to the front-rear direction of the crane, of the internal mast element, at the base of the latter, and two recess housings arranged inside the corresponding faces of the external element,

the embedding pads being provided with engagement and release ramps,

• and two symmetrical folding latches, articulated at the top of the external mast element and controlled automatically during the telescoping of the mast elements, the latches cooperating with the pads and the recessing housings of the upper blocking assembly, coming from s 'engage, once folded, respectively between the two pads and the corresponding housings.

These provisions make it possible to carry out embedding an interior mast element on a external mast element, in telescoped position, for ensure the transmission of all the efforts of an element from mast to mast. In addition, they transition suitable between guidance function and function embedding, and vice-versa, taking up the efforts of the guide.

Overall, the particular means of guidance and locking, previously defined, allow to dissociate the functions of embedding and guidance which are subjected to efforts of a nature different, and thereby optimize the achievement of each of these functions, while allowing the transition from one to the other. In addition, the structure of these means makes visible, from the ground, the maneuvers of locking and unlocking.

Figure 1 est une vue d'ensemble, de côté, d'une grue à tour pourvue d'une mâture conforme à la présente invention, représentée à l'état télescopé ;

Figure 2 est une vue de côté partielle de la mâture, montrant un élément de mât intérieur et un élément de mât extérieur en cours de télescopage ;

Figure 3 est une vue en coupe horizontale suivant III-III de figure 2, montrant les moyens de guidage situés à la base de l'élément de mât intérieur ;

Figure 4 est une vue en coupe horizontale suivant IV-IV de figure 2, montrant les moyens de guidage situés au sommet de l'élément de mât extérieur ;

Figure 5 est une vue de côté partielle de la mâture, similaire à la figure 3 mais montrant l'élément de mât intérieur verrouillé avec l'élément de mât extérieur ;

Figure 6 est une vue en coupe horizontale suivant VI-VI de figure 5, montrant l'ensemble de blocage supérieur et les verrous ;

Figure 7 est une vue en coupe horizontale suivant VII-VII de figure 5, montrant l'ensemble de blocage inférieur.

In any case, 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 telescopic mast for a tower crane:

Figure 1 is an overall side view of a tower crane provided with a mast according to the present invention, shown in the telescoped state;

Figure 2 is a partial side view of the mast, showing an inner mast member and an outer mast member during telescoping;

Figure 3 is a horizontal sectional view along III-III of Figure 2, showing the guide means located at the base of the inner mast member;

Figure 4 is a horizontal sectional view along line IV-IV of Figure 2, showing the guide means located at the top of the outer mast element;

Figure 5 is a partial side view of the mast, similar to Figure 3 but showing the inner mast member locked with the outer mast member;

Figure 6 is a horizontal sectional view along line VI-VI of Figure 5, showing the upper blocking assembly and the latches;

Figure 7 is a horizontal sectional view along VII-VII of Figure 5, showing the lower locking assembly.

• un premier élément de mât 7, ou élément inférieur, articulé par sa base au châssis tournant 2,
• un deuxième élément de mât 8, ou élément intermédiaire, monté coulissant à l'intérieur du premier élément de mât 7, et
• un troisième élément de mât 9, ou élément supérieur, monté coulissant à l'intérieur du deuxième élément de mât 8.

The tower crane, shown very diagrammatically in FIG. 1, comprises a fixed base chassis 1 supporting a rotating chassis 2, orientable around a vertical axis 3. The rotating chassis 2 carries a counterweight 4 at the rear, and at the front of this rotating frame 2 is articulated, around a horizontal axis 5, a telescopic mast designated as a whole by the reference 6, composed of three mast elements 7, 8 and 9 mounted to slide relative to each other , is :

• a first mast element 7, or lower element, articulated by its base to the rotating frame 2,
• a second mast element 8, or intermediate element, slidably mounted inside the first mast element 7, and
• a third mast element 9, or upper element, slidably mounted inside the second mast element 8.

The crane still has a boom dispenser 10, foldable, which is linked to the top of the mast 6 along a hinge axis 11, and which is held in a horizontal position by a device retainer 12, connected to the rear part of the chassis turning 2.

The present invention is more concerned particularly to the structure of the telescopic mast 6, the elements of which are shown in more detail in Figures 2 and following. In the following description of these elements, we will distinguish an interior mast element and an external mast element, which in the example illustrated are respectively the second mast element 8 and the first mast element 7 (but which could be also the third and second elements).

• quatre faces obliques 18, 19, 20 et 21, adjacentes aux faces avant 14 et arrière 15, et formant des angles de 60° par rapport au plan médian 13 ;
• quatre autres faces obliques 22, 23, 24 et 25, adjacentes aux faces latérales droite 16 et gauche 17, et formant des angles de 30° par rapport au plan médian 13.

Il est aussi possible de considérer que les huit faces obliques 18 à 25 sont réparties en quatre paires de faces obliques adjacentes, respectivement : 18-22, 19-23, 20-24 et 21-25.The mast elements 7, 8 and 9 are all three constituted by boxes, having a dodecagonal section, that is to say in the form of a polygon with twelve sides. Each mast element thus has twelve solid side faces. To define the orientations of these faces, reference will be made to the longitudinal median plane 13 of the rotating part of the crane, corresponding to the front-rear direction of this crane, the front being the side towards which the tip of the arrow is directed. vending machine 10.
Thus, each mast element 7, 8 or 9 has a front lateral face 14 and a rear lateral face 15, perpendicular to the median plane 13, a right lateral face 16 parallel to the median plane 13, and a left lateral face 17 also parallel to the median plane 13. The first four lateral faces 14 to 17, previously defined, are connected together by intermediate faces or oblique faces, a total of eight, designated 18 to 25. We can distinguish here:

• four oblique faces 18, 19, 20 and 21, adjacent to the front 14 and rear 15 faces, and forming angles of 60 ° relative to the median plane 13;
• four other oblique faces 22, 23, 24 and 25, adjacent to the right 16 and left 17 lateral faces, and forming angles of 30 ° relative to the median plane 13.

It is also possible to consider that the eight oblique faces 18 to 25 are distributed in four pairs of adjacent oblique faces, respectively: 18-22, 19-23, 20-24 and 21-25.

Guiding an inner mast element 8 by relative to an external mast element 7 is produced at by means of guide shoes, fixed on the oblique faces respectively 18, 19, 20 and 21 (adjacent to the front faces 14 and rear 15) of these two mast elements 7 and 8.

More specifically, as shown in the figure 3, first four guide shoes 26, 27, 28 and 29 are provided at the base of the inner mast element 8. These guide shoes 26, 27, 28 and 29 are fixed, respectively, on the four oblique faces 18, 19, 20 and 21 of the inner mast element 8, outside of this item 8.

As shown in Figure 4, four more pads guide 30, 31, 32, and 33 are provided at the top of the outer mast element 7. These guide pads 30, 31, 32 and 33 are fixed, respectively, on the four oblique faces 18, 19, 20 and 21 of the mast element 7, at inside this element 7.

Each of the guide pads 26 to 33 has, as shown in Figures 3 and 4, a width substantially equal to that of the oblique face 18, 19, 20 or 21 next to which it is located, and with which he is called to cooperate. Figure 2 also illustrates, at A and B, the support zones between the pads of an element of mast and the corresponding faces of the other element of mast.

Thanks to the guide pads 26 to 33 previously described, the inner mast element 8 can be telescoped, until reaching with respect to the external mast element 7 a predetermined vertical position, in which it is automatically locked with this external element 7. To this end, locking means are provided, shown mainly in Figures 5, 6 and 7.

These means include a blocking assembly upper, composed of two mounting pads 34 and 35 and two recessed housings 36 and 37. Both mounting pads 34 and 35 are arranged outside of the two lateral faces, respectively straight 16 and left 17, of the inner mast element 8; these skates 34 and 35 are equipped with engagement and clearance ramps 38 and 39. The two mounting housings 36 and 37 are arranged inside the side faces, respectively right 16 and left 17, of the outer mast element 7, at the top of this element 7.

The locking means also include a lower locking assembly, consisting of two others mounting pads 40 and 41 and two other housings 42 and 43. The two 40 mounting pads and 41 are arranged towards the base of the mast element inside 8, outside the two lateral faces, respectively right 16 and left 17, of this element 8. These pads 40 and 41 are also provided with ramps of engagement and clearance 44 and 45. The two housings 42 and 43 are arranged inside the corresponding faces 16 and 17 of the mast element exterior 7.

The upper blocking assembly is completed by two symmetrical locks 46 and 47, pivotally mounted at top of the outer mast element 7, around an axis of horizontal pivot 48 perpendicular to the median plane 13 and close to the upper edge of the rear face 15 of this item 7.

At the end of the telescoping of the mast element interior 8, the mounting pads 34, 35, 40 and 41 come to cooperate with the corresponding housings 36, 37, 42 and 43, as shown in Figure 5. Both latches 46 and 47, initially held in the raised position and moved back (see also figure 2), are folded down to engage, respectively, between the two pads 34, 35 and the corresponding housings 40, 41 of the assembly upper mounting. The support zones of an element mast on the other, operating in the locked position, are shown in C, D and E in Figure 5.

Conversely, the two locks 46 and 47 are cleared and raised, when it comes to entering the element inside 8 in the outside element 7.

• en prévoyant une section en forme de dodécagone irrégulier (angles et/ou côtés inégaux), au lieu d'une section en forme de dodécagone régulier (angles et côtés égaux),
• plus généralement en prévoyant d'autres sections polygonales, régulières ou non, à plus de quatre côtés,
• en appliquant l'invention à une mâture télescopique composée seulement de deux éléments, ou composée de plus de trois éléments,
• en modifiant le détail des moyens de guidage et de verrouillage.

We would not depart from the scope of the invention:

• by providing an irregular dodecagon-shaped section (unequal angles and / or sides), instead of a regular dodecagon-shaped section (equal angles and sides),
• more generally by providing other polygonal sections, regular or not, with more than four sides,
• by applying the invention to a telescopic mast composed only of two elements, or composed of more than three elements,
• by modifying the detail of the guide and locking means.

Claims (5)

1. Telescopic mast structure (6) for a tower crane, composed of several mast elements (7, 8, 9) mounted so that they can slide one inside another and each having a box-like structure, characterized in that the box-structure mast elements (7, 8, 9) each have a cross section of polygonal shape with more than four sides, which is determined by lateral faces (14 to 17) which are parallel and/or perpendicular to the fore-aft direction (13) of the crane, and intermediate lateral faces (18 to 25) which are oblique with respect to this fore-aft direction (13), the said mast structure (6) comprising means (26 to 33) for guiding the mast elements (7, 8, 9) one with respect to another, these means being situated on oblique lateral faces (18 to 21) of these mast elements (7, 8, 9), and means (34 to 48) for automatically locking the said mast elements (7, 8, 9) together in predetermined relative positions, which means are arranged on lateral faces (16, 17) which are parallel and/or perpendicular to the fore-aft direction (13) of the crane.
2. Telescopic mast structure for a tower crane according to Claim 1, characterized in that the box-structure mast elements (7, 8, 9) each have a cross section of dodecagonal shape which is determined by two opposite lateral faces (16, 17) which are parallel to the fore-aft direction (13) of the crane, a front lateral face (14) and a rear lateral face (15) which are perpendicular to the fore-aft direction (13) of the crane, and eight oblique faces (18 to 25) arranged in four pairs of adjacent oblique faces connecting, in pairs, the previous lateral faces (14 to 17).
3. Telescopic mast structure for a tower crane according to Claim 2, characterized in that the guide means comprise, in combination, for an inner mast element and outer mast element pairing:

   four guide shoes (26 to 29) situated at the base of the inner mast element and fixed on the outside to the oblique faces (18 to 21) of this element which are adjacent to the front face (14) and rear face (15), and

   four more guide shoes (30 to 33) which are situated at the top of the outer mast element and fixed on the inside to the oblique faces (18 to 21) of this element which are adjacent to the front face (14) and rear face (15).
4. Telescopic mast structure for a tower crane according to Claim 3, characterized in that the guide shoes (26 to 33) consist of a slip plate covering more or less the entire width of the corresponding oblique face (18 to 21), the plate being covered with a coating of synthetic material that reduces the coefficient of friction.
5. Telescopic mast structure for a tower crane according to any one of Claims 1 to 4, characterized in that the means for automatically locking the mast elements (7, 8, 9) together comprise, in combination, for an inner mast element and outer mast element pairing:

   an upper locking assembly composed of two lateral engagement shoes (34, 35) arranged on the outside of the lateral faces (16, 17) which are parallel to the fore-aft direction (13) of the crane and belong to the inner mast element, and of two engagement housings (36, 37) arranged on the inside of the corresponding faces (16, 17) of the outer mast element, at its top,

   a lower locking assembly composed of two more lateral engagement shoes (40, 41) arranged on the outside of the lateral faces (16, 17) which are parallel to the fore-aft direction (13) of the crane and belong to the inner mast element, at its base, and of two engagement housings (42, 43) arranged on the inside of the corresponding faces (16, 17) of the outer element,

   the engagement shoes (34, 35, 40, 41) being provided with engagement and disengagement ramps (38, 39, 44, 45),

   and two symmetric turn-down latches (46, 47) articulated (at 48) to the top of the outer mast element and operated automatically as the mast elements (7, 8, 9) are deployed, the latches (46, 47) interacting with the engagement shoes (34, 35) and the engagement housings (36, 37) of the upper locking assembly by engaging, once turned down, between the two shoes (34, 35) and the corresponding housings (36, 37), respectively.

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