Description of the prior art It is known that railway cars and rolling stock in general call for the frequent performance of ordinary and extraordinary maintenance operations. To this end, therefore, appropriate workshops are distributed all long the railway network, where the railway cars, though always kept on the rails, are taken every time they stand in need of interventions of a certain complexity and which therefore call for adequate infrastructures and specialized labour.

Particular importance attaches to the operations of repairing/replacing the external components of the cars.

This primarily because these components are subject to greater wear and tear and therefore call for more frequent and more numerous repair interventions. Secondarily, because as a general rule they are also more critical from the point of view of the operational safety of the vehicle. Lastly, because they engender greater logistical difficulties that are due to both the need for operating at a certain height above ground, and the need for employing complex and rather bulky machinery/instruments.

There is thus a greatly felt need for equipment capable of facilitating the task of the maintenance workers, enabling

them to work on all the external parts of the cars in conditions that will assure the greatest possible comfort and a maximum of safety.

Summary of the invention The object of the present invention is to fully satisfy the need discussed above and, more particularly, to provide an item of equipment that, due to a novel combination of its components, will be capable of appreciably improving the quality of maintenance work performed on the outside of railway cars, increasing the productivity of the repair operations and, at the same time, permitting it to be carried out in greater safety.

This object is achieved with the supporting platform for railway car maintenance workers according to the present invention, to be placed close to the body side of said car and characterized in that it comprises: a motor- operated trolley with a lateral side which extends along the direction of its movement and is intended to be arranged close to the body side of said car; a raisable horizontal footboard supported by the trolley; and a pair of projecting structures comprising respective walking planes, said structures being arranged at the forward and rearward ends of the horizontal footboard, with respect to the direction of motion of the trolley, and being movable between a non-working position in which they do not project beyond the lateral side of the trolley, and a working position in which they do project beyond this side, holding out the walking planes beyond the lateral side of the trolley in a position that is substantially coplanar with the footboard.

According to a preferred solution, the projecting structures are pivotable around an axis which is raisable

integrally with the footboard and extends along the direction of motion of the trolley, so that in said non- working position and in said working position the projecting structures are respectively lifted and lowered, said two positions being spaced by a rotation through substantially 90°.

Brief description of the drawings The characteristics and advantages of the multifunctional mobile platform for the maintenance of railway cars according to the present invention will be described more in detail hereinafter with the description of a preferred embodiment thereof, which is to be considered as an example and not limitative in any way, said description making reference to the attached drawings, in which: - figure 1 shows a side elevation of the platform according to the invention; - figures 2a and 2b show respectively a top plan and a front elevation of the platform of figure 1, provided with pivotable projecting structures in the lifted position; - figures 3a and 3b show, respectively, a top plan and front elevation of the platform of figure 1, with the pivotable structures in the lowered position; - figure 4 shows the axle region of the platform of the previous figures to a larger scale and partly in section; figure 5 shows a detail of the region of figure 4 seen in the direction of the arrow V of said figure; - figures 6a and 6b show, respectively, a top plan and front elevation of a pair of opposed platforms in working configuration for performing maintenance work on

the roof of a railway car; - figures 7a and 7b show, respectively, a top plan and front elevation of a pair of opposed platforms in working configuration for performing maintenance work on the frontal face of a railway car.

Detailed description of the invention Referring to figures 1 to 5, the platform according to the present invention comprises a base trolley 1 movable on wheels 2 distributed over two axles 3, one of which is motor-driven. Preferably, as in the illustrated example, the wheels 2 move on rails 4 situated next to and parallel with the rails (not shown in the figure) intended to carry the car that is to be repaired. Alternatively, the trolley 1 may be carried on tyred wheels. The two front sides of the trolley 1, i. e. the two sides which cross the direction of motion, are provided with stop devices la, which perform collision-prevention functions.

As shown in detail by figures 4 and 5, with each axle 3 there is associated a system to prevent the trolley 1 from overturning, said system comprising, for each wheel 2, a pair of sliding blocks 5, one mounted upstream and the other downstream the wheel. Each sliding block 5 consists of a stirrup 5a that projects downwards from the trolley 1 and four rollers 5b carried by the stirrup 5a, these rollers forming two pairs arranged on opposite sides of the stirrup. The rollers 5b slide within two opposed C- shaped guides 6 formed below the appropriate rail 4.

From the trolley and, more precisely, its lateral side opposite the one that faces the railway line, there rise two uprights 7 and from these there extends horizontally, above the trolley 1, a shelf structure 8.

The shelf 8 is mounted on the uprights 7 by means of a

sliding arrangement, so that it can be raised and lowered into any desired position under the action of a transport system powered by an oil-pressure circuit, which is not shown in detail since its configuration would be obvious to a person skilled in the art.

The shelf 8, in its turn, sustains a footboard 9 intended as a support for the personnel occupied on the maintenance work and for this purpose provided with perimeter guard rails 10 to prevent accidental falls. The footboard 9, just like the shelf 8, has a width that is less than the width of the trolley 1. It can however be displaced with respect to the shelf 8, in a direction perpendicular to the direction of motion of the trolley 1, in such a way that it can assume both a rearward position in which it is in contact with the uprights 7 (as in the figures) and a forward position in which it projects beyond the free lateral edge lb of trolley 1, i. e. the edge adjacent to the item of rolling stock on which the work is to be performed. Using appropriate actuator means, this movement is once again powered by the oil-pressure circuit mentioned above.

The shelf structure 8 also supports a pair of projecting structures 11 arranged close to respective front edges of the footboard 9, i. e. at the forward and rear end thereof in relation to the direction of motion of the trolley 1. More precisely, each projecting structure 11 has a walking plane lla and a guard rail llb that rises from the perimeter of said walking plane lla. In the zone adjacent to the uprights 7 the guard rail lib is hinged to the shelf structure 8, so that the projecting boards-in this particular embodiment-can be pivoted about a longitudinal axis Y between a vertically lifted position

(figures 2a and 2b) and a lowered or working position (figures 1, la and lb), these two positions being spaced by an angle of about 90°, so that the walking planes will be vertical when lifted and horizontal when lowered. In the lowered position the walking planes lla are coplanar with the footboard 9 and project beyond the free lateral side lb of the trolley 1. This further movement is likewise controlled by the previously mentioned oil- pressure circuit.

The guard rails llb are interrupted in the parts adjacent to the footboard 9, thus enabling the maintenance crews to gain access to the walking planes lla, and also at the distal end edge of the projecting structures, from which there extend respective telescopic appendices 13.

The latter, in their turn, are provided with a walking plane 13a, which prolongs the walking plane lla of the projecting structure 11 even further beyond the free lateral side lb of the trolley 1. In particular, as will be explained more clearly further on, in the lowered position and with the appendix 13 fully extended, each structure 11 projects beyond the side 1b by a distance that substantially corresponds to half the standard width of railway cars and rolling stock in general. The appendices 13 are also provided with perimeter guard rails similar to the guard rails lib of projecting structures 11.

The workmen on the footboard 9 stand in need of supply means for the tools/instruments normally used in the repair and maintenance operations. To this end the platform according to the invention is connected to circuits supplying such resources as-typically-oxygen, fuel gas, oil and electricity, the latter being used also

for powering the propulsion of the platform and its parts.

As can clearly be seen, especially in figure 1, the connection is effected by means of hanging chains 15 that contain the cables/pipes and are supported coaxially by a beam 14 rising from the trolley 1 and are also dragged by it whenever the trolley changes position.

Referring now to the various figures from 6a to 7b, it will be noted that the chains 15 are connected to the trolley 1 from above and, more precisely, by means of a horizontal suspension system 16 that extends in the direction of motion of the trolley and is integral with the infrastructures (not shown in the figure) of the repair shop. It can be noted in figures 6b and 7b that a chain segment 17 reaches the footboard 9, on which there are situated not only the plug-in point of the various power sources mentioned above, but also control panels 18 (see figure 6b) for the movement of the trolley 1, the shelf 8, the footboard 9 and the projecting structures 11.

Lastly, it should be noted that the trolley 1 is provided with a general electric control panel 19 to which there is connected, in addition to the various auxiliary power components, also a PLC that, with the help of an appropriate sensor network and in a manner obvious for a person skilled in the art, administers the programmed logic of the platform movements as described further on.

Still referring to the various figures from 6a to 7b, which show the platform in its working configuration around a railway car 12, it should be noted that the movement of trolley 1 and the raising of the shelf structures 8 (and therefore of the footboard 9) makes it possible for the maintenance crew to work in conditions of maximum comfort and safety at any height and in any

longitudinal position along a body side of the car 12. The positioning of the shelf structures 8 at the desired height must necessarily be effected with the projecting structures 11 in the non-working position and with the footboard 9 in its rearward position, thereby avoiding all risk of bumping into the side of the car under repair.

Nevertheless, when the platform is in the position at the end of the car 12, one of the projecting structures 11, namely the one that can be moved without interfering with the car 12, may be lowered. This makes it possible to realize the configuration shown in figures 7a and 7b by using two identical and opposed platforms on the two sides of the vehicle. Thanks to this configuration, the two projecting structures 11, when lowered into their working position and with their respective appendices 13 fully extended, form a kind of gangway that, running alongside the front face of the car 12, renders all the points thereof readily accessible.

When the shelf structures 8 reach their upper end- of-run position, i. e. with the footboard 9 in its highest position, it becomes possible for said footboard, which is now above the roof of the car 12, to be moved further forward and for both the projecting structures 11 to be lowered, thus obtaining the configuration shown in figures 6a and 6b. In this configuration, still using two opposed platforms exactly aligned with each other, the footboards 9 and the projecting structures 11 with their respective appendices 13 form a four-sided gangway on which the maintenance workers can move (as shown in figure 6b, where they are indicated by the reference number 20), thus rendering the roof of the vehicle readily accessible for carrying out maintenance work thereon.

It should be noted that, with a view to avoiding damage to the car or other items of rolling stock, the PLC management system prevents the shaft structure 8 from being moved when the footboard 9 is in its forward position and/or one or both of the projecting structures 11 are lowered into their working position. Furthermore, as has already been mentioned, the footboard 9 cannot be moved forward except when the shelf structures 8 are in their upper end-of-run position.

It is readily apparent that the platform according to the invention fully attains the aims it set out to achieve, providing in practice a mobile production area that can be easily configured to meet all specific needs of the maintenance workers with respect to the rolling stock to be maintained and is capable of placing at their disposal the power supplies for the equipment needed for a highly variegated range of interventions, even the most complex. And all this with a maximum of safety. The quality and the productivity of the maintenance operations are thus considerably enhanced.

The projecting structures 11, rather than being pivotable, could be such as to be simply held out transversely with respect to the side lb by means of a telescopic solution similar to the one already mentioned in connection with the appendix 13. In that case a base frame of such form as not to project beyond the side lb of the trolley 1 will either be connected to the footboard 9 or incorporated in it, while the actual projecting structure (possibly, in its turn, provided with an appendix 13) will be joined to the frame by means of a sliding fit, so that it can be extended into its working position beyond the side lb.

The footboard 9, too, can be provided with a walk-on appendix to be extended transversely with respect to the side lb. Indeed, rather than being of a substantially parallelepiped shape as in the illustrated example, the end of the car could be wedge-shaped and have tapering body sides according to the aerodynamic design typical of modern locomotives. In that case it will be useful to have an appendix of the footboard 9 with a free edge shaped in such a manner as to reproduce the top plan outline of the end of the car. Thanks to this expedient, whenever the platform has to be placed against such a car end, the walkway surface can be extended so as to skirt the perimeter of the car, which becomes translated into an obvious advantage in terms of efficacy of the maintenance operations that can be carried out and safety for the men engaged in the work.

Variants and/or modifications can be brought to the multifunctional mobile platform for the maintenance of railway cars according to the present invention without for this reason going beyond the scope of the invention as defined by the claims hereinbelow.