FR2761969A1 - DEVICE FOR TELESCOPIC LADDERS AND MOBILE ELEMENT GUIDED ON THESE LADDERS, FOR A TOWER CRANE - Google Patents

Abstract

The device applies to a tower crane with telescopic mast in three parts, equipped with a telescopic ladder (13) also in three parts (14, 15, 16), a ladder element being associated with each element of mast. The ladder element (15) associated with the intermediate mast element has uprights (26) of crenellated profile, which surround the uprights (22, 24) of the other two ladder elements (14, 16). The mobile element, to be guided on the ladder (13), comprises a guide frame, the frame of which (32) carries first guide rollers (33, 34) located opposite the right and left side faces of the ladder (13), and other guide rollers (37 to 42) which clamp two by two the uprights (22, 24, 26) of the ladder elements (14, 15, 16), and which find passage in the parts concaves (27) of the uprights (26) of the ladder element (15). The mobile element is in particular a crane cabin.

Description

The present invention relates, in general, to the field of cranes

  tower and it relates, more particularly, to a device combining telescopic ladders and a mobile element guided on these ladders, for a tower crane with telescopic mast in three elements equipped with telescopic ladders also in three elements, an element of scale associated with

  each tower element of the tower crane.

  By "mobile element" is meant here any transport element which can be moved and guided vertically, over the height of the mast totally or partially

  deployed crane, for example: crane cab, hoist

  load, hoist, protective gondola for crane operator. Tower cranes are already known, the masts of which include ladders used for guiding a mobile element. In particular, Swiss patent 665825 and European patent application 0175052 describe tower cranes, in which the ladders provide guidance for an elevator cabin. We can also cite French patent application 9604980 of April 16, 1996 in the name of the Applicant, in which the ladders are used to guide a protective nacelle, constituting a secure access device to the cabin, for the crane operator.

climbing along the ladders.

  Considering more particularly the Swiss patent 665825, this document describes a crane with telescopic mast in two elements, provided with a ladder also telescopic and produced in two main elements, associated respectively with the two mast elements; the upper ladder element has uprights of rectangular profile, and the lower ladder element has uprights of "U" profile coming to surround the uprights of the upper element on three of their four faces. On this scale is mounted rolling a mobile chassis, provided with four rollers and four guide rollers, the latter having a groove in a "V" profile, said movable chassis being secured to the cabin. The telescopic ladder comprises, in addition to its two main elements, a short "slide" element, which has a profile corresponding to that of the lower ladder element, but which is slidably mounted on the upper ladder element . Thus, when the cabin is mounted, the movable chassis first rolls directly on the lower ladder element, then, reaching the top of the lower ladder element, it engages on the slide element in the waiting position, and carries with it this slide element, by means of which it is then guided along the upper ladder element. Thus, a special slide element is required here to make the connection of

  profile between the two main scale elements.

  The sliding element of the ladder may get stuck during its movement, due to the high friction, this element having no running roller. A simple stop device provides the drive connection between the movable chassis and said slide element, while a locking system would be necessary to say the least, for safety purposes, in particular to avoid that during the descent of the cabin the movable frame is no longer guided if the slide element gets stuck, which could even lead to

falling from the cabin.

  Thus, the solution of Swiss patent 665825 is complex, unreliable and insecure, even very dangerous, while being limited, in its application, to a crane with telescopic mast in two elements. In particular, the document considered does not provide any solution

  applicable to a telescopic mast in three elements.

  The aforementioned European patent application 0175052 is

  also limit to the description of a scale in two

  telescopic elements, and this document does not provide any details of the means for guiding the mobile element, in particular as regards the passage without interruption from one ladder element to another. In general, the previous documents show solutions which also appear insufficient to ensure appropriate guidance of the movable element in all directions, while also ensuring the recovery of the forces due to a load which, necessarily, is offset relative on the way to

  bearing formed by the scales.

  The present invention aims to remedy all of these drawbacks by providing a telescopic ladder device and a movable element guided on these ladders, specially designed for a telescopic mast in three elements, the proposed device permanently guiding suitable in the front, rear, right and left directions, as well as the resumption of the forces due to the offset load, also ensuring a continuous passage from one ladder element to the next, in order to globally produce a reliable device and adapted, ensuring perfectly safe guidance, while retaining a relatively simple and compact structure. To this end, the subject of the invention is a device for telescopic ladders and a movable element guided on these ladders, for a tower crane with telescopic mast in three elements fitted with telescopic ladders also in three elements, an element of ladder being associated with each mast element of the tower crane30, the device being characterized in that: - the ladder element, associated with the lower and outer mast element, is fixed to its upper part and to its lower part on this mast element, and has two uprights of square or rectangular section, connected by bars, - the ladder element, associated with the upper and inner mast element, is fixed to its upper part on this mast element, and has two uprights of square or rectangular section, connected by bars, the width of this ladder element being equal to that of the previous one, - the ladder element, ass associated with the intermediate mast element, is fixed by its upper part to this mast element, and has two uprights of crenellated profile, having in their middle a concave part and, on either side of the concave middle part, two convex parts capable of enveloping the corresponding uprights of the other two ladder elements, the bars of this ladder element connecting the concave middle parts of its two uprights, and the width of this ladder element being equal to that of the two other ladder elements, - the movable element, to be guided on the ladder, includes a guide frame itself composed: * of a frame of horizontal section in the shape of a "U", surrounding the ladder on its front face and on its lateral faces, * first guide rollers, with horizontal axes, located opposite the right and left lateral faces of the ladder, and able to roll along the right and left lateral faces of the uprights of the ladder elements associated with the exterior and interior mast elements, and also along the convex convex parts of the ladder element associated with the intermediate mast element, * other guide rollers, with orthogonal horizontal axes to the axes of the preceding rollers and distributed on the right and left sides of the ladder, and comprising rollers taking place on either side of the respective uprights of the three ladder elements, with central rollers finding passage in the concave part crenellated profile uprights of the ladder element associated with the

intermediate mast.

  The telescopic ladder thus consists of two classic elements, and a more specific element, the uprights of which have a particular profile ensuring, by its enveloping convex parts, a sliding connection with the two preceding elements and, by its concave middle part , the passage of at least one guide roller belonging to the movable element to be guided along the ladder. The attachments of the three ladder elements to the corresponding mast elements allow the ladder to be deployed and retracted without encountering any obstacle. The profile chosen for the three ladder elements makes it possible to obtain a minimum size of the ladders when they are retracted, therefore to satisfy the requirements of road gauge for the transport of the crane, and this profile also achieves a "natural" structure. guide, in four directions forming angles of 90 between them, for the guide frame which supports a

  means of transport such as a crane cabin.

  Thanks to its sets of rollers, this guide frame for the movable element ensures guiding in perfect safety, because, when it passes over each of the three ladder elements, there are always rollers which enclose the amounts of the scale element concerned. Arranged in two perpendicular directions35, these rollers provide lateral guidance and guidance in the front-rear direction, as well as the recovery of lateral and / or front-rear forces due to the load supported by said guide frame. The configuration proposed by the invention also ensures, in the vertical direction, a guiding continuity in the passage from one ladder element to the next. According to a preferred embodiment of the invention, the guide rollers belonging to the guide frame of the movable element comprise two sets of eight guide rollers, located respectively at the base and at the top of said frame and each comprising: - two large guide rollers located respectively opposite the right and left lateral faces of the scale, and - six smaller guide rollers, distributed in two groups of three rollers located respectively on the right and left sides of the scale, these rollers enclosing two by two the uprights of the ladder elements associated with the outer, inner and intermediate mast elements, the central roller of each group of three rollers finding passage in the concave part of the crenellated profile upright of the ladder element associated to

the intermediate mast element.

  In any case, the invention will be better understood at

  using the following description, with reference to the drawing

  attached schematic showing, by way of example, an embodiment of this device of telescopic ladders and of mobile element guided on these ladders, for tower crane: Figure 1 is a side view of a tower crane equipped with the device which is the subject of the invention, the mobile element being the cabin of the crane; Figure 2 shows, in side view, the scales of this crane with their attachment points to the mast; Figure 3 is a horizontal sectional view showing the profiles of the scales; Figure 4 shows, in isolation, the particular profile of the ladder element associated with the intermediate mast element; Figure 5 is a perspective view of the movable element, namely the cabin, with indication of a section of the ladder on which this movable element is guided. In Figure 1 is shown a tower crane, which comprises a fixed base frame i on which is rotatably mounted, around a vertical axis 2, another frame 3 which carries a counterweight 4 at the rear and at before which is mounted, along a horizontal axis 5, a telescopic mast 6. The crane is provided with a distributing jib 7 (shown only partially), mounted at the top of the mast 6. Guy lines 8 connect the

  rotating frame 3 and mast 6, while a rear retaining device 9 connects the arrow 7 to the rotating frame 3.

  The telescopic mast 6 consists of an outer and lower element 10, an intermediate element 11 and an inner and upper element 12. Each mast element 10, 11 or 12 has for example a square section

or polygonal.

  The telescopic mast 6 is equipped with a ladder 13, which is also telescopic, which consists of three ladder elements 14, 15 and 16, associated respectively with the three mast elements 10, 11 and 12. The telescopic ladder 13 is shown, in the partially deployed position, on the

figure 2.

  The first ladder element 14, associated with the external mast element 10, is fixed to this external mast element 10 at a lower fixing point 17 and at an upper fixing point 18. To allow the retraction of the ladder, the second ladder element 15, associated with the intermediate mast element 11, is fixed to this intermediate mast element 11 only at an upper fixing point 19. Likewise, the third ladder element 16, associated to the inner mast element 12, is fixed to this inner mast element 12 only at an upper fixing point 20. The telescopic ladder 13 is used to guide an element movable vertically along the mast 6, this movable element being the crane cabin 21 in the example illustrated in the drawing. For this purpose, the scale elements 14, 15 and

  16 have the relative configurations and positions shown in FIGS. 3 and 4.

  The first ladder element 14 comprises two uprights 22 of square profile, connected by bars 23.

  The third ladder element 16 also comprises two uprights 24 of square profile, connected by bars 25.

  These two scale elements 14 and 16 are of the same width, so that their respective uprights 22 and 24 come

  opposite, in the retracted position of the ladder 13.

  The second ladder element 15 has a more particular configuration, clearly visible in FIG. 4. This ladder element 15 has two uprights 26 of crenellated profile, which can be described as having a concave middle part 27, located between two convex parts 28 and 29. The bars 30 of this ladder element 15 connect the concave middle parts 27 of its two uprights 26. The width of this second ladder element 15 is equal to that of the first and third

scale elements 14 and 16.

  In the retracted position of the telescopic ladder 13, the second ladder member 15 takes place between the first ladder member 14 and the third ladder member 16. The convex portions 28 of the uprights 26 of the second ladder member 15 come to wrap the corresponding uprights 22 of the first ladder element 14. The other convex parts 29 of the uprights 26 of the second ladder element 15 come to wrap the corresponding uprights 24 of the third ladder element 16. Referring to FIG. 5 , the crane cabin 21 is supported by a guide frame 31, located behind this cabin 21 and on one side thereof. The guide frame 31 comprises a frame 32 made of tubes, which extends vertically over the height of the cabin 21 and which has a horizontal section in the shape of a "U", surrounding the ladder 13 on its front face and on its of them

side faces.

  The frame 32 of the guide frame 31 supports two identical sets of guide rollers, located respectively at the base and at the top of this frame 31, and each comprising eight guide rollers. Figure 315 clearly shows the arrangement of these eight rollers,

  for one of the two sets of guide rollers.

  Two large guide rollers 33 and 34, with respective horizontal axes 35 and 36, are located one facing the right side face, and the other facing the left side face of the scale 13. According to the degree of deployment of the ladder 13 and the position of the crane cabin 21, the large guide rollers 33 and 34 are capable of rolling: - along the right and left lateral faces of the uprights 22 of the first ladder element 14 , and / or - along the convex parts 28 and 29 of the uprights 26 of the second ladder element 15, and / or - along the right and left lateral faces of the

  uprights 24 of the third ladder element 16.

  Six smaller guide rollers 37 to 42 are provided, the axes of which are horizontal and orthogonal to the axes 35 and 36 of the large rollers 33 and 34. A first group of three equidistant small rollers 37, 38 and 39 is provided on the right side of the ladder 13, and a second group of three small equidistant rollers 40, 41 and 42 is provided on the left side of the ladder 13. These small rollers enclose two by two the uprights of the ladder elements 14, 15 and 16. In other words: - The uprights 22 of the first ladder element 14 are enclosed, on the right, by the pair of rollers 37 and 38 and, on the left, by the pair of rollers 40 and 41, each pair comprising a

  outer roller and a central roller.

  - The uprights 24 of the third ladder element 16 are enclosed, on the right, by the pair of rollers 38 and 39 and, on the left, by the pair of rollers 41 and 42, each pair comprising a

  outer roller and a central roller.

  - The uprights 26 of the second ladder element 15 are enclosed, on the right, by the pair of rollers 37 and 39 and, on the left, by the pair of rollers 40 and 42, each pair comprising the

two outer rollers.

  In addition, the two central rollers 38 and 41 find passage in the concave middle parts 27 of the

  two uprights 26 of the second ladder element 15.

  As shown in FIG. 5, the movable element guided on the ladder 13 also comprises a platform 43 for access to the cabin 21, the platform 43 comprising a hatch and being located opposite the ladder 13, thus

  that opposite door 44 of cabin 21.

  The frame 31, support of the cabin 21, can be hoisted or lowered along the ladder 13 by any suitable lifting means, such as rope, rope or cable, generally moved by a winch itself actuated by a motor or manually. These elevation means comprise in themselves the safety devices intended to prevent the fall of the frame 31, therefore of the movable element 21 such as the crane cabin, in the event of a breakdown of the driving energy. Figure 1 shows several positions, namely a lower position, an intermediate position and a position

  in which the cabin 21 can be brought.

  The two sets of eight rollers 33, 34, 37 to 42 of the guide frame 31 ensure guiding in perfect safety, during the displacement of the cabin 21, because for each ladder element 14, 15 or 16 , these rollers enclose the uprights 22, 24 or 26, the operation being possible with the telescopic mast 6 fully or partially deployed. In addition, the device ensures the recovery of the forces due to a load offset from the scale 13, which is the case here for the cabin 21, offset both laterally and forwards relative to the scale 13. It goes without saying that the invention is not limited to the only embodiment of this device of telescopic ladders and of movable element guided on these ladders which has been described above, by way of example; on the contrary, it embraces all of the variant embodiments and applications respecting the same principle.20 In particular, one would not depart from the spirit of the invention by giving the mobile element any configuration , other than that of a cabin, and by assigning it any function: transport of persons, transport of equipment, protection of personnel. Similarly, telescopic ladders can

  be mounted, indifferently, outside or inside the mast.

Claims (3)

  1 - Device of telescopic ladders and mobile element guided on these scales, for crane & tower with telescopic mast in three elements equipped with telescopic ladders also in three elements, a ladder element being associated with each mast element of the tower crane, characterized in that: - the ladder element (14), associated with the lower and outer mast element (10), is fixed to its upper part (at 18) and to its part lower (at 17) on this mast element (10), and has two uprights (22) of square or rectangular section, connected by bars (23), - the ladder element (16), associated with the upper and inner mast element (12), is fixed at its upper part (at 20) to this mast element (12), and has two uprights (24) of square or rectangular section, connected by bars (25), the width of this scale element (16) being equal to that of the previous one (14), - the ladder element (15), associated with the intermediate mast element (11), is fixed by its upper part (in 19) to this mast element (11), and has two uprights (26) of crenellated profile, having in their center a concave part (27) and, on either side of the concave middle part (27), two convex parts (28,29) capable of enveloping the corresponding uprights (22,24) of the two other elements ladder (14, 16), the bars (30) of this ladder element (15) connecting the concave middle parts (27) of its two uprights (26), and the width of this ladder element (15 ) being equal to that of the other two scale elements (14,16), the movable element (21), to be guided on the scale (13), comprises a guide frame (31) itself composed: * a frame (32) of horizontal section in the shape of a "U", surrounding the ladder (13) on its front face and on its lateral faces, * of first guide rollers (33, 34), with horizontal axes (3 5.36), located opposite the right and left side faces of the ladder (13), and able to roll along the right and left side faces of the uprights (22,24) of the ladder elements (14,16 ) associated with the external (10) and internal (12) mast elements, and also along the enveloping convex parts (28, 29) of the ladder element (15) associated with the intermediate mast element (11) , * other guide rollers (37 to 42), of horizontal axes orthogonal to the axes (35,36) of the preceding rollers (33,34) and distributed on the right and left sides of the scale (13), and comprising rollers (37 to 42) taking place on either side of the respective uprights (22,24,26) of the three ladder elements (14,16,15), with central rollers (38,41) finding passage in the concave parts (27) of the uprights (26) of crenellated profile of the ladder element (15) associated with the element intermediate mast (11).   2 - Device according to claim 1, characterized in that the guide rollers belonging to the guide frame (31) of the movable element (21) comprise two sets of eight guide rollers (33,34,37 to 42), located respectively at the base and at the top of said frame (31) and each comprising: - two large guide rollers (33,34) located respectively opposite the right and left lateral faces of the ladder (13), and - six smaller guide rollers (37 to 42), distributed in two groups of three rollers (37,38,39; 40,41,42) located respectively on the right and left sides of the scale (13), these rollers ( 37 to 42) enclosing two by two the uprights (22,24,26) of the ladder elements (14, 16,15) associated with the exterior (10), interior (12) and intermediate (11) mast elements, the central roller (38,41) of each group of three rollers finding passage in the concave part (27) of the corresponding amount (26) of the inte mat element intermediate (11). 3 - Device according to claim 1 or 2, characterized in that the movable element (21), guided on   the ladder (13) is a crane cabin.