EP0803466B1 - Method and device for safety ascending to a cab, in particular on a tower crane - Google Patents

Description

The present invention relates to a method for secure access to a high operator position, plus particularly in the cabin of a tower crane. She has also for object a device, intended for setting process work. This invention finds its particular application for access to the tower crane cabin automated assembly, with telescopic or folding mast, used on building construction sites.

In service, the cabin of such a crane is generally arranged at the top of the mast, so that the crane operator, taking place in this cabin for driving of the crane, can have good visibility on all work operations. To access the cabin, the crane mast is traditionally fitted with ladders and fixed "crinoline" protective cages, arranged either inside the mast when the cross section of this mast is sufficient for the passage of the crane operator, outside the mast when the section of the mast is insufficient, which is often the case for cranes with automated assembly.

In all cases, the scales must include rest stages, placed at levels such that each scale flight does not exceed an authorized value. Of preferably, successive flights of scales are laterally offset from each other, to ensure better ergonomics. Nevertheless, in progress up or down ladders, the crane operator is not not immune to a fall inside the crinoline, up to several meters high, inside the crinoline. Fixed crinolines do not therefore are not perfect protections against risk of falling.

In addition, if the scales and crinolines are arranged outside the mast, the crinolines in particular have a wind resistance important, which limits the mechanical resistance and the operating range of the crane in service. The presence of outdoor crinolines also involves space additional which hinders the folding of the crane into position transportation, as well as increased vulnerability.

To overcome some of the disadvantages previous, we know by the European patent application N ° 0.175.052 an embodiment in which the cabin is sliding climb along the crane mast, and in which the crinoline device of the access ladders to the cabin, composed of hoops also sliding on along the mast and connected together by cables or straps, hangs under the cabin. In position of transport of the crane, the cabin is lowered at the foot of the mast, and the hoops of the crinoline device stack on top of each other, then presenting a footprint as small as possible. Such a achievement is interesting for road transport of the crane, but it presents technical difficulties and a significant additional cost, in particular to ensure the correct guiding of the crinoline arches during the sliding, and maintaining in position of these arches. Another mobile complete cabin device vertically is known from Swiss Patent No. 665,825.

We also know access devices to the summit of the mast of a crane, in particular of high height, constituted by a real elevator car running at inside the mast - see patent application International No. WO 92/18412. Such a solution is not conceivable only for section mast cranes important transverse. She is particularly expensive, because it requires motor means, braking means and safety devices specific.

Furthermore, in the area of scales in general, many devices have already been proposed more or less effective safety, for the rise and descending the ladder, as well as devices forming work or intervention platform, which can be placed at the desired height on a scale.

• Le dispositif n'assure pas une protection complète, c'est-à-dire à la fois latérale, inférieure et éventuellement supérieure de l'opérateur.
• L'utilisation d'un tel dispositif est particulièrement fatigante, puisque l'utilisateur doit monter à l'échelle par la seule force de ses jambes, sans pouvoir s'aider de ses bras.
• Cet inconvénient est aggravé par le fait que le dispositif ne comporte aucun moyen de compensation de son poids, lequel s'ajoute à celui de l'utilisateur.
• Le dispositif n'offre pas une sécurité véritable, au sens d'une immobilisation ferme de ce dispositif sur l'échelle, à toute hauteur; l'utilisation de la seule pression de ressorts est notablement insuffisante pour immobiliser le protecteur sur les montants de l'échelle.
• L'entraínement du dispositif le long de l'échelle, lors de la montée, se fait seulement par la tenue des poignées, ce qui impose un geste volontaire et inhabituel; une sangle entre-jambes retient l'utilisateur mais ne permet pas l'entraínement du dispositif vers le haut, lors de la montée de l'échelle.
• Le dispositif ne comporte aucun moyen facilitant son accès depuis l'extérieur, et la sortie de l'utilisateur; en particulier, il n'est prévu aucune disposition permettant à l'utilisateur, parvenu en position haute, de sortir en toute sécurité du protecteur, pour gagner un poste de conduite élevé, notamment une cabine de grue à tour qui se situerait sur le côté de l'échelle.
• Enfin, ce dispositif connu n'est pas véritablement adapté au passage d'une échelle à une autre, avec guidage continu, alors que les grues à mât télescopique ou repliable possèdent habituellement une succession d'échelles. Ainsi, la solution révélée par la demande de brevet français N° 2.495.684, au demeurant formulée de manière très succincte, s'avère non ergonomique et même totalement irréaliste, en particulier vis-à-vis du domaine spécifique d'application de la présente invention.

In particular, French patent application No. 2,495,684 discloses a sliding protector, constituted by a sort of carriage rolling along the uprights of a ladder, and provided laterally with handles gripped by the operator when the l 'ladder. This device in itself has many drawbacks, and it is neither intended nor adapted for access to a high driving position, such as a crane cabin:

• The device does not provide complete protection, that is to say at the same time lateral, bottom and possibly top of the operator.
• The use of such a device is particularly tiring, since the user must climb the ladder by the sole force of his legs, without being able to use his arms.
• This drawback is aggravated by the fact that the device does not include any means of compensating for its weight, which is added to that of the user.
• The device does not offer real security, in the sense of a firm immobilization of this device on the ladder, at any height; the use of spring pressure alone is notably insufficient to immobilize the guard on the uprights of the ladder.
• The drive of the device along the ladder, during the climb, is done only by holding the handles, which requires a voluntary and unusual gesture; a crotch strap retains the user but does not allow the drive of the device up, when climbing the ladder.
• The device has no means facilitating its access from the outside, and the exit of the user; in particular, no provision is made for the user, having reached the high position, to exit the guard in complete safety, in order to gain a high driving position, in particular a tower crane cabin which would be situated on the side of the scale.
• Finally, this known device is not really suitable for passing from one ladder to another, with continuous guidance, whereas cranes with telescopic or folding mast usually have a succession of ladders. Thus, the solution revealed by French patent application No. 2,495,684, moreover formulated very succinctly, turns out to be non-ergonomic and even completely unrealistic, in particular with regard to the specific field of application of the present invention.

French patent application No. 2,518,519 reveals a lifting device, intended to facilitate the ascent of a crane operator on a tower crane, the device being presented mainly as a mobile seat, suspended on a cable, and further comprising a counterweight and possibly a drive motor.

In this known device, the seat is neither maintained or guided on the ladder or another part from the crane mast, this seat simply hanging from the cable. Therefore, if the crane operator is unwell it can tilt around the seat or even with this seat, with the additional risk of hitting the bars of the ladder or parts of the crane mast, and stay hanging upside down. In addition, the device is not nature to surround and protect the crane operator on all sides. This device therefore does not provide protection and appropriate security, which are precisely the goals of the present invention.

Furthermore, with its mobile part limited to one simple seat, the patent application device French N ° 2.518.519 does not allow the transport of tools, documentation or any other object useful for the crane maintenance personnel. Finally, this device cannot constitute a work platform, for maintenance personnel.

French patent application No. 2,682,098 describes a safety device, for tower cranes and others, which includes a cable and a counterweight, the cable being intended to be connected, by a hook which is fixed to a belt or harness, with the person using the scale. This document does not provide any protection that would accompany the person moving along the ladder and who would surround that person, and the ladder remains fitted with a classic fixed crinoline, while the present invention specifically aims to remove the crinoline and its drawbacks.

We can also point out U.S. Patent No. 2,245,661, in which a harness device is described, movable along a ladder and used for execution work at height. Thus, this device constitutes a small work platform, can be hung on the desired level on the rungs of a ladder but like the previous ones it is not designed for secure access to a driving position located high up, especially at the cabin of a tower crane.

The object of the present invention is to remedy the disadvantages outlined above, by providing a method and a device for secure access to a high driving, especially in the cabin of a tower crane, which limit the effects of wind to increase the mechanical resistance and the autonomy height of the crane, and which facilitate the folding of the crane for its road transport, while ensuring ergonomics and optimum safety, both during the ascent and lowering the mast only when the crane operator the ladder to the cabin, and vice versa.

For this purpose, it is essentially proposed a procedure for secure access to a driving position high, especially on a tower crane, accessible by a mast or the like in one or more parts fitted laterally from one or more access ladders to a cockpit or cabin, process which according to the invention is to use a protective device individual, mobile along the mast, maintained and guided on the ladder or successively on the scales and trained along the mast, via a resting harness on the shoulders of the crane operator or a harness supporting the crane operator, on the path of this crane operator when climbing along the ladder or ladders to the cabin, and conversely when descending from the cabin.

As can be easily understood, the fact of using an accompanying mobile personal protection device the crane operator during his ascent or descent, between the floor and cabin, removes fixed crinolines traditional, thus limiting the effects of the wind, thanks to the significant reduction of surfaces exposed to the wind. Removing crinolines also makes folding easier and transporting the crane, and makes it a lot less vulnerable; note that for the transport of crane, the personal protective device is reduced to the base of the crane mast, or even removed from the crane. This device mainly provides protection as close as possible to the crane operator, and he can also ensure, at any time and in any position along the mast, a rest platform function or intervention.

As indicated above, the personal protection is trained, along the mast, by through a harness resting on the shoulders of the crane operator, or a harness supporting the crane operator. In all cases, the personal protective device can thus accompany the crane operator, during the climb or the descending the ladder, which are always carried out in a normal gesture, the crane operator putting his hands and feet on the rungs of the ladder.

The device, according to the invention, for secure access at a high operator position, especially on a crane turn, for the implementation of the process defined above, includes a personal protective carrycot, accessible from the outside, inside which the crane operator can stand upright, the basket being provided with holding and guiding means on the ladder or ladders of the mast, and a harness or harness for its training by the crane operator, the device further comprising means of compensation for the weight of the basket and the means immobilization of said nacelle.

Advantageously, the protective nacelle is presents as a rigid structure closed but perforated, composed of horizontal arches joined by rails vertical, of a floor located at its base and having a function of rest and intervention platform, and, possibly, a protective roof in its part superior. Thus, this structure provides protection lateral, dorsal, lower and, if applicable, superior. The floor also allows to lay in any safety of tools or documentation necessary for maintenance staff.

According to an additional characteristic, the protective nacelle is provided with an access door lateral, opening inwards, and a hatch relief in the floor. The side door facilitates the access of the crane operator inside the nacelle, when it is in the low position, and it above all allows, in the high position of the nacelle, a safe passage of the crane operator from the gondola to the cabin, and vice versa. The fact that the door opens only towards the inside of the nacelle avoids any risk falling from being pushed against this door, or an untimely opening whatever the cause, while the nacelle is located at an intermediate height.

According to another characteristic, the means of holding and guiding the protective basket consist of pairs of rollers mounted in rows respectively on cross members symmetrically fixed on either side of the nacelle, on the one hand, at its lower part or floor and, on the other hand, to a intermediate level between the bottom or floor and the upper part of the nacelle, the pairs of rollers continuously supported on the amounts of the ladder or ladders of the mast.

According to an additional characteristic, in the case of a mast with successive elements, of sections different from each other, carrying scales respective, it is expected that free spaces, substantially equal to the thickness of the ladder uprights of the mast, are provided between the different lines of rollers, in correspondence with the different positions ladders on the mast elements. The passage of the protective basket, from one scale to the next, is thus carried out without discontinuity, whatever the number of scales.

In a particular embodiment, the means of compensating for the weight of the gondola protection consists of a winch, equipped with a motor torque, attached to the top of the mast, the winch cable descending directly above the nacelle and being fixed in a point located at the top of said nacelle. These means to compensate for the weight of the nacelle driven by the crane operator, so that the effort to provided by the crane operator during the climb is not practically not increased. In addition, by adjusting appropriate effort to compensate for the weight of the nacelle, it is ensured that the nacelle is actually trained by the crane operator, either by through the harness, either through the harness.

As for the means of immobilization of the nacelle of protection, in a particular mode of execution, these consist of a reel fitted with an anti-fall device operating by inertia, known per se, fixed at the top of the mast substantially in line with the nacelle, the cable the reel being fixed at a point located at the part upper of said nacelle. Such means stop immediately when the gondola begins to fall, crane operator inside.

The previously defined device is more particularly applicable to access to a cabin of a self-erecting tower crane, telescopic mast or foldable composed of successive mast elements carrying respective scales, on which is maintained and guided the protective basket. It can be, between others, of a tower crane whose cabin, to which this device gives access, is itself mobile along the crane mast, and in particular guided on the same scales than the protective basket. Such a cabin can be immobilized at any intermediate height, and note that the device according to the invention allows in this case access to the cabin, whatever its level immobilization.

Even more particularly, the invention is applicable to a tower crane with telescopic mast in which scales, other than the item scale lower mast, are rigidly fixed, only by their upper part at the top of the mast element corresponding, the scales being offset transversely with respect to each other and being provided with a central rail for holding and guiding from the lower end of the ladder of the mast element immediately higher, this end being equipped a rolling and / or sliding means cooperating with the rail. These provisions allow the mast to be telescoped with its ladders, and ensure the maintenance in position of ladders, to allow the passage of the gondola protection from one ladder to the next, when climbing, or to the previous one, during its descent.

Figure 1 est une vue latérale d'ensemble, à l'état monté, d'une grue à tour à laquelle s'applique le procédé selon l'invention, la nacelle de protection du dispositif d'accès à la cabine occupant sa position basse;

Figure 2 est une vue arrière d'ensemble de la même grue, correspondant à la figure 1;

Figure 3 est une vue latérale d'ensemble de la même grue, la nacelle de protection occupant sa position haute;

Figure 4 est une vue arrière de la même grue, correspondant à la figure 3;

Figure 5 est une vue latérale de détail de la nacelle de protection, guidée sur une échelle et associée à des moyens de compensation de son poids et d'immobilisation, dans une première forme de réalisation;

Figure 6 est une vue en plan par dessus de la nacelle de protection selon la figure 5, montrant sa disposition par rapport à la cabine de la grue;

Figure 7 est une vue latérale de détail de la nacelle de protection, guidée sur une échelle et associée à des moyens de compensation de son poids et d'immobilisation, dans une seconde forme de réalisation;

Figure 8 est une vue arrière de détail de la nacelle de figure 7, montrant sa disposition par rapport à la cabine de la grue;

Figure 9 est une vue en plan par dessus de cette nacelle, correspondant à la figure 8;

Figure 10 est une vue latérale partielle du mât, et des échelles associées, d'une grue à tour à laquelle est appliquée l'invention;

Figure 11 est une vue en plan par dessus de l'ensemble d'échelles équipant le mât de cette grue.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended diagrammatic drawing which, by way of example, illustrates modes of implementation of this method for secure access to a high operator position, and represents embodiments of the associated device, in the case of application to a tower crane:

Figure 1 is an overall side view, in the assembled state, of a tower crane to which the method according to the invention applies, the protection nacelle of the access device to the cabin occupying its low position ;

Figure 2 is an overall rear view of the same crane, corresponding to Figure 1;

Figure 3 is an overall side view of the same crane, the protective nacelle occupying its high position;

Figure 4 is a rear view of the same crane, corresponding to Figure 3;

Figure 5 is a detail side view of the protective nacelle, guided on a ladder and associated with means of compensation for its weight and immobilization, in a first embodiment;

Figure 6 is a plan view from above of the protective nacelle according to Figure 5, showing its arrangement relative to the crane cabin;

Figure 7 is a detail side view of the protective nacelle, guided on a ladder and associated with means of compensation for its weight and immobilization, in a second embodiment;

Figure 8 is a rear detail view of the nacelle of Figure 7, showing its arrangement relative to the cabin of the crane;

Figure 9 is a plan view from above of this nacelle, corresponding to Figure 8;

Figure 10 is a partial side view of the mast, and associated ladders, of a tower crane to which the invention is applied;

Figure 11 is a plan view from above of the set of ladders fitted to the mast of this crane.

The tower crane, represented as a whole at Figures 1 to 4, comprises in a known manner a base frame fixed or rolling 1 supporting, by means of a orientation device 2 with vertical axis 3, a chassis turning 4 which carries a mast 5. This tower crane is provided with a dispensing arrow 6, carried by the top of the mast 5 and kept horizontal by means of a tie rod 7, a punch 8 and a rear shroud 9, connected to the rear of the rotating chassis 4.

In the particular case illustrated in the drawing, the mast 5 is telescopic. It consists of three mast elements successive 10, 11, 12 including cross sections are different and decreasing from bottom to high, to allow telescoping. Each mast element 10, 11, 12 carries a ladder, respectively 13, 14, 15, laterally attached to this mast element. As shown schematically in FIGS. 2 and 4, the scales 13, 14, 15 are offset transversely, relative to each other to others; this provision will be explained below.

The crane is provided with a cabin 16, carried by the mast 5 and offset laterally with respect to this mast 5 and arrow 6. The cabin 16 occupies in particular, when the crane is in service, a high position, at the top of the mast 5. However, it should be noted that this cabin 16 can also be immobilized at an intermediate height on mast 5, when the crane is in service, or be lowered at the foot of the mast 5 for folding the crane, said cabin 16 being guided on ladders 13, 14, 15.

According to the invention, the crane is equipped with a device for access to cabin 16, placed at the chosen height, this device allowing the crane operator safely access cabin 16 from the ground. The device generally comprises a nacelle of protection 17 inside which the crane operator can stand stand upright, means of compensation 18 for the weight of the nacelle 17, and means 19 for immobilizing said basket 17.

As shown in Figures 5 and 6, relating to a first embodiment of this device, the nacelle protection 17 has a rigid, closed structure but openwork, composed of horizontal arches 20 joined by vertical beams 21, a floor 22 located at the base of the structure, and a harness 23 located in the half superior of this structure.

The protective nacelle 17 is equipped, at the level from floor 22 and at an intermediate level between the floor 22 and harness 23, of two superimposed pairs horizontal rails 24 and 25, symmetrically fixed on either side of the nacelle 17. The crosspieces 24 and 25 carry rollers 26 and 27 respectively, with axes horizontal, spaced horizontally from the thickness e of uprights 28 of the ladders 13, 14, 15 of the mast 5. In the example illustrated, each crosspiece 24 or 25 carries four rollers 26 or 27 mounted in lines, sparing between them three identical free spaces of value e, corresponding respectively when passing the uprights 28, offset horizontally, different scales 13, 14, 15.

The protective nacelle 17 is still provided a side access door 29, articulated around an axis vertical 30 and opening towards the inside of the nacelle (see Figure 6), and an emergency hatch 31 provided in floor 22.

The upper part of nacelle 17, indicated in 32, possibly forms a protective roof, not shown in detail.

The means of compensation 18 for the weight of the nacelle 17 consist, in the examples considered, of a winch 33, fitted with a torque motor, the cable 34 of which is fixed, at an attachment point 35, to the upper part 32 of the nacelle 17. The winch 33 is fixed to the top of the mast 5; it can in particular be supported by the platform 36 of the crane lifting winch.

The immobilization means 19 of the nacelle of protection 17 consist, for their part, of a reel 37 automatically unwinding or winding a cable 38 which is fixed, at a point of attachment 39, to the upper part 32 of the nacelle 17. The reel 37 is provided with a anti-fall device operating by inertia; he can still be provided with a control cable, provided for manual control. This reel 37 is fixed at the top of mast 5, and it can in particular be supported by the platform 36 of the crane lifting winch.

The means of immobilization 19 previously described allow immobilization of the nacelle protection 17 at any intermediate height. These means are advantageously supplemented by means, mechanical or electro-mechanical, for locking platform nacelle 17 in the low position and in high position, with manual unlocking.

The operation of the device previously described, for access to cabin 16 of the crane, is the following :

At the outset, as shown in Figures 1 and 2, the crane is in the assembled state with the cabin 16 arranged at the top of mast 5 (cabin 16 having been previously brought to the top of the mast, if it is a cabin that can also occupy a low position). The gondola protection 17 is in the low position, and it is accessible from the rotating chassis 4, by through a recipe platform 40.

In this configuration, the crane operator accesses directly inside nacelle 17 through the door lateral 29; he goes into the usual up position of the lower ladder 13, and initiates the rise of this scale 13.

As soon as the first steps of scale 13 are gravis, the crane operator's shoulders are supported under the harness 23 of the nacelle 17. Thus, continuing from climb normally on ladder 13, the crane operator drives with him, through harness 23, nacelle 17 whose weight is compensated by the tensile force, directed upwards, exerted by the cable 34 of the winch 33. Meanwhile, the cable 38 belonging to the means 19 is wrapped automatically on the reel 37, to ensure the safety of movement of nacelle 17 throughout its ascent, accompanying that of the crane operator, along the mast 5.

The nacelle 17 first moves along the lower element 10 of the mast 5, the first pairs of rollers 26 and 27 ensuring its guidance and its maintenance on the amounts 28 of the scale 13 associated with this element lower 10. When the nacelle 17 driven by the crane operator crosses the lower mast element 10 to the intermediate mast element 11, the second pairs of rollers 26 and 27 take over from the first pairs of rollers, ensuring continuity of guidance and maintenance on the uprights 28 of the following scale 14. Likewise, when the nacelle 17 which reaches higher crosses the passage of the intermediate mast element 11 to the upper mast element 12, the third pairs of rollers 26 and 27 intervene to ensure continuity guiding and holding on the uprights 28 of the last scale 15. The nacelle 17 thus accompanies the crane operator, during the entire ascent of the mast 5, ensuring side and back protection, one position intermediate of nacelle 17 being indicated on the figure 2.

Finally, the nacelle 17 arrives, with the crane operator, in its high position located at the cabin 16 - see figures 3 and 4. The nacelle 17 is automatically locks in this high position, and the crane operator accesses directly inside the cabin 16, the door of which comes in correspondence with the door lateral 29 of nacelle 17, the relative arrangement of cabin 16 and nacelle 17 also appearing clearly in Figure 6.

Conversely, the crane operator descends from the crane with the protective nacelle 17, after having unlocked manually said nacelle.

To ensure correct operation, uphill as downhill, harness 23 must exercise in permanently an effort directed downwards and substantially constant, of the order of a few kilograms, over the shoulders of the crane operator. The value of this effort is regulated by via the winch torque motor 33 compensation for the weight of the nacelle 17. In others terms, the self-weight of this nacelle 17 must not be fully compensated, so that harness 23 remains resting on the crane operator's shoulders.

The previously described device allows the crane operator, locking gondola 17, to rest at any time during its climb or descent along mast 5, placing itself on the floor 22. This device also allows the crane operator to intervene in any intermediate point in the path between the ground and the cabin 16, the floor 22 of the nacelle 17 making then office work platform. During such interventions, the harness 23 can be retracted so as not to not hinder the crane operator in his movements.

In case of crane operator discomfort, or incident technique causing blocking of the nacelle protection 17 at a point far from the ground, the personnel of rescue or maintenance can intervene to rescue the crane operator, using ladders 13, 14, 15 of mast 5 and individual safety equipment, access to the interior of the nacelle 17 being made possible in particular by the emergency hatch 31.

Figures 7 to 9 show another form of realization of the protective nacelle 17, in which unmodified elements (compared to the first form are designated by the same references, and do not will not be described again. In this second embodiment, the harness is replaced by a harness 41, composed of one or more straps moored to the rigid structure of the nacelle 17. Unlike the previous embodiment, the means of compensation 18 exert an effort here on the nacelle directed upwards which is greater than the dead weight of nacelle 17, so that the harness 41 supports the crane operator at all times. It is thus guaranteed that the nacelle 17 accompanies the crane operator during the ascent or lowering the mast 5.

Figures 10 and 11 show details of scales 13, 14, 15 respectively associated with the three elements 10, 11, 12 of the telescopic mast 5. The ladder 13 of the lower mast member 10 is located closest to the central axis 3 of the mast 5. The ladder 14 of the mast element intermediate 11 is offset towards the outside, relative to the previous scale 13. The scale 15 of the element of upper mast 12 is itself offset towards the outside, compared to the previous scale 14. The two scales 14 and 15, other than scale 13 of the mast element lower 10, are rigidly fixed only by their upper part at the top of the mast element 11 or 12 correspondent, through a pair horizontal spacers 42. In addition, the ends lower of the two scales 14 and 15 are maintained and guided, respectively, on the two scales 13 and 14.

To this end, each scale 13, 14, 15 comprises, over its entire height, a vertical median rail 43, of "T" section. The lower end of the ladder upper 15 is provided with a holding pad and guide 44, engaged on the middle rail 43 of the ladder intermediate 14. Similarly, the lower end of this intermediate ladder 14 is provided with a holding and guiding 45, engaged on the middle rail of the lower scale 13.

These provisions allow sliding relative of the three scales 13, 14, 15, accompanying the telescoping of the mast 5. In addition, in relation to the device object of the present invention, they ensure keeping ladders 13, 14, 15 in position with the required horizontal spacing, corresponding to the diameter rollers 26 and 27, between their respective uprights 28, what is necessary for the passage of the gondola protection 17, from one scale to the next or to the previous, during the ascent or descent of the crane operator.

We would not stray from the scope of the invention as defined by the claims by applying the even proceeded to access to driving positions, taking or not the shape of a cabin, always located in height, but belonging to other lifting and handling, such as port cranes, gantry cranes, bridges rollers, etc ..., always provided with at least one mast or similar part, also known as "leg" or "palée", laterally equipped with one or more access ladders at the driving position. We wouldn't go away, either, of the scope of the invention as defined by claims by modifications of forms and constructive details, concerning the protective basket and its guidance along the mast of the crane or other device lifting or handling, or concerning the means of compensation for the weight of the gondola and the means immobilization of said nacelle, or concerning ladders with their holding and guiding means, where the sliding pads can be replaced or supplemented by rolling means.

Claims (11)

1. Method for safe access to a high-level control station, notably on a tower crane, accessible by means of a mast or the like (5) in one or more parts (10, 11, 12) equipped laterally with one or more ladders (13, 14, 15) giving access to a control station or cab (16), characterised in that it consists of using an individual protective device (17, 18, 19), movable up and down the mast (5), held and guided on the ladder or in succession on the ladders (13, 14, 15) and driven up and down the mast (5), by means of a harness (23) resting on the shoulders of the crane driver or a cross belt (41) supporting the crane driver, on the route of this crane driver when lie is climbing up the ladder or ladders (13, 14, 15) as far as the cab (16), and conversely when descending from the cab (6).
2. Device for safe access to a high-level control station, notably on a tower crane, for implementing the method according to Claim 1, characterised in that it comprises an individual protective gondola (17), accessible from the outside, inside which the crane driver can stand upright, the gondola (17) being provided with means of holding and guiding (24, 25, 26, 27) on the ladder or ladders (13, 14, 15) on the mast (5), and a harness (23) or cross belt (41) for driving it by the crane driver, the device also comprising means (18) of compensating for the weight of the gondola (17) and means of immobilising (19) the said gondola (17).
3. Device for safe access to a high-level control station, according to Claim 2, characterised in that the protective gondola (17) is in the form of a rigid structure which is closed but which has apertures in it, composed of horizontal hoops (20) joined by vertical rails (21), a floor (22) situated at its base and having the function of a resting or working platform and, optionally, a protective roof at its top part (32).
4. Device for safe access to a high-level control station, according to Claim 3, characterised in that the protective gondola (17) is provided with a side access door (29), and an emergency trap door (31) provided in the floor (22).
5. Device for safe access to a high-level control station, according to any one of Claims 2 to 4, characterised in that the means of holding and guiding the protective gondola (17) consist of pairs of rollers (26, 27) mounted in lines respectively on cross members (24, 25), fixed symmetrically on each side of the gondola (17), on the one hand at the level of its bottom part or floor (22) and on the other hand at a level intermediate between the bottom part or floor (22) and the top part (32) of the gondola (17), the pairs of rollers (26, 27) bearing continuously on the uprights (28) of the ladder or ladders (13, 14, 15) on the mast (5).
6. Device for safe access to a high-level control station, according to Claim 5, characterised in that free spaces, substantially equal to the thickness (e) of the uprights (28) of the ladders (13, 14, 15) on the mast, are provided between the different lines of rollers (26, 27), in correspondence with the different positions of the ladders (13, 14, 15) on successive mast sections (10, 11, 12), with different cross sections from each other.
7. Device for safe access to a high-level control station, according to any one of Claims 2 to 6, characterised in that the means (18) for compensating for the weight of the protective gondola (17) consist of a winch (33), equipped with a torque motor, fixed to the top of the mast (5), the cable (34) of the winch (33) descending vertically above the gondola (17) and being fixed at a point (35) situated at the top part (32) of the said gondola (17).
8. Device for safe access to a high-level control station, according to any one of Claims 2 to 7, characterised in that the means (19) of immobilising the protective gondola (17) consist of a winder (37) provided with an anti-fall device operating by inertia, fixed to the top of the mast (5) substantially vertically above the gondola (17), the cable (38) of the winder (37) being fixed at a point (39) situated at the top part (32) of the said gondola (17).
9. Device for safe access to a high-level control station, according to any one of Claims 2 to 8, characterised by its application to access to the cab (16) of a self-erecting tower crane, with a telescopic or folding mast (5) composed of successive mast sections (10, 11, 12) carrying respective ladders (13, 14, 15), on which the protective gondola (17) is held and guided.
10. Device for safe access to a high-level control station on a tower crane, according to Claim 9, characterised in that the cab (16) to which this device gives access is itself movable up and down the mast (5) of the crane, and notably guided on the same ladders (13, 14, 15) as the protective gondola (17).
11. Device for safe access to a high-level control station, on a telescopic-mast tower crane according to Claim 9 or 10, characterised in that the ladders (14, 15), other than the ladder (13) on the bottom mast section (10), are rigidly fixed (at 42) only by their top part to the top of the corresponding mast section (11, 12), the ladders (13, 14, 15) being offset transversely with respect to each other and being provided with a middle rail (43) for holding and guiding the bottom end of the ladder (14, 15) on the immediately higher mast section (11, 12), this bottom end being equipped with a rolling and/or sliding means (44, 45) cooperating with the rail (43).

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