GAMBA, Gianfranco (Via Statuto 6, Bergamo, I-24128, IT)
| CLAIMS 1) Self-propelled, railway work-vehicle with mobile work platform for the construction and maintenance of railway overhead power lines, of the type comprising a motorised support railway vehicle (1) and a lifting device provided with a mobile work platform (4) mounted on said vehicle (1), characterized in that said lifting device consists of an adjustable assembly (2) mounted on a fifth wheel and provided with an adjustable arm (3) with a telescopic extension (3a) , at the free end of which there is fastened said work platform (4) and in that the motorization of said railway vehicle is a hybrid motorisation comprising at least an inner combustion engine and at least an electric motor. 2) Railway work-vehicle as claimed in claim 1) , wherein said railway vehicle (1) is a 2-axle vehicle and said adjustable assembly is fastened to the vehicle in correspondence of one of said axles . 3) Railway work-vehicle as claimed in claim 2), wherein said telescopic arm (3, 3a) is hinged on said adjustable assembly (2) to have a rotation movement in a vertical plane between a horizontal, fully drawn-in home position and a sub-vertical, fully extended work position at maximum height. 4) Railway work-vehicle as claimed in claim 3), wherein said adjustable assembly (2) is furthermore provided with an automatic control for keeping it in an always perfectly horizon- tal position, regardless of the position of the arm (3) and of the opening degree of the telescopic extension (3a) and of the lateral or longitudinal inclination of the railway vehicle (1) plane . 5) Railway work-vehicle as claimed in claim 4) , wherein said mobile platform (4) is apt to rotate by 180° with respect to the end of the telescopic extension (3a) which supports the same . 6) Railway work-vehicle as claimed in claim 4), having an overall bulk, in the home position of said telescopic arm (3, 3a), of 2.5 m width, 4.3 m length and 2.8 m height with respect to the track plane. 7) Railway work-vehicle as claimed in any one of the preceding claims, wherein said mobile platform (4) has a maximum operating height of 7,5 m with respect to the track plane when the centre of equilibrium of the platform lies above the ve- hicle, or a maximum height of about 6.5 m with a maximum longitudinal or lateral range of about 4.20 m with respect to the vertical rotation axis of the adjustable assembly (2) . 8) Railway work-vehicle as claimed in any one of the preceding claims, wherein the rotation movement of the adjustable assembly (2), the telescopic and rotation movements of the telescopic arm (3, 3a) and the rotation movement of the mobile platform (4) are controlled by hydraulic drives. 9) Railway work-vehicle as claimed in claim 8) , further comprising a central processing unit which automatically causes rectilinear movements of the mobile platform (4) along the axes X (horizontal direction parallel to the track) , Y (horizontal direction perpendicular to the track) and Z (vertical direction) , by the interpolation of said hydraulic drives. 10) Railway work-vehicle as claimed in claim 9), further comprising automatic anti-collision devices apt to block the movement of the telescopic arm (3, 3a) and of the mobile platform (4), when the distance between parts of these elements and the overhead line drops below a preset threshold value. 11) Railway work-vehicle as claimed in claim 1) , where said internal combustion engine is a high-efficiency, reduced- emission Diesel engine. 12) Railway work-vehicle as claimed in claim 1), wherein said electric motor is powered by a series of maintenance-free gel drive batteries integrated in the flatcar of the railway ve- hicle (1) . 13) Railway work-vehicle as claimed in claim 12), further comprising multiple alternative means for obtaining the recharge of said batteries, such as: means which use the movement produced by said internal combustion engine, means for connecting to an external power network, means for the recovery of the kinetic energy of the vehicle during the braking phases. 14) Railway work-vehicle as claimed in claim 1) , wherein said engine and motor control the two axles of the vehicle independently from one another. |
DESCRIPTION
FIELD OF THE INVENTION
The present invention refers to a railway work-vehicle with mobile platform for the maintenance of railway overhead power lines. In particular, the invention concerns improvements of such vehicle in connection with the safety handling of the platform, the operators' working comfort and the propulsion of the vehicle.
STATE OF THE PRIOR ART
Work-vehicles for maintaining railway overhead power lines were devised virtually together with the railways' electrification and have hence been known for a long time. In their initial version, they were simple bogies with no motorisation, on the flatcar of which a fixed castle was anchored carrying one or two rung vehicles, at the top of which a fixed work platform was often found. From this structure the name ladder-bogie derives, which is frequently still used today in the Italian industry to refer to such type of vehicles. The more generally used name of work-vehicle will be used throughout the present description.
In actual fact this primitive solution has by now been largely abandoned in favour of work-vehicles with Diesel motorisation and movable platforms, wherein said platform is capable of hydraulic movements along the vertical axis (Z axis) and along a horizontal axis (Y axis) perpendicular to the track direction (said last axis being referred to as X axis) . Normally it is also possible to cause the movable platform to rotate about the vertical axis, at least for a certain sector of a cir- cle, so that the movements of the platform along the horizontal axis may occur - at least within said sector - in any direction in the XY plane.
After this first evolution, the above-described work- vehicles have not been the subject of further improvements, de- spite the fact that they show substantial drawbacks during the use thereof, which drawbacks will be briefly summarised in the following.
A first, major drawback is linked to the insufficient work safety which characterised these work-vehicles, especially when operators must work on the suspension ropes of the overhead power line. As a matter of fact, during the lifting phase the work platform can at most reach a position wherein the highest parts thereof (normally the fall-preventing side railings) end up touching the contact wires of the overhead power line, on the axis of which it is aligned; in this position, however, the platform is still too low to enable the operators to work with a sufficient degree of comfort on the suspension ropes, especially in the proximity of the support shelves of the catenary where the distance between suspension ropes and contact wires reaches the highest value. In situations of this type, which in fact are very frequent in maintenance operations, operators must hence necessarily use improvised solutions, pulling themselves up in conditions of unstable balance onto the highest parts of the platform - such as for example the protection railings, possibly with the help of planks resting on the same - to be able to work at a suitable height, with serious consequences precisely on their safety, despite the fact that this improper use of the vehicle is strictly forbidden by current regulations, which establish that operators on the platform must always be able to reach comfortably all the positions within the work area and always with their feet resting securely on the surface of the floor of the platform.
A second drawback of work-vehicles of the known type depends on the fact that the platform thereof is parallel to the vehicle plane and rigidly follows the movements thereof . There derives hence that in upwards sloping sections or, more so in the curved sections of the track, the work plane of the platform is not horizontal, but inclined in a longitudinal direction up to 3% and crosswise up to 10%, thus not offering operators a steady work position which is comfortable and especially safe.
A third drawback is finally connected to the Diesel mo- torisation of known-type work-vehicles, which motorisation has all the limits and drawbacks linked to the high noise level and to the emission of exhaust gases of this type of engines. In particular the use of current work-vehicles in the proximity of inhabited areas, especially at night-time, which is more fre- quently dedicated to maintenance operations, hence results in great nuisance and complaints, while the use of work-vehicles within tunnels determines great discomfort to operators due to air pollution from exhaust gases, especially in case of long tunnels with low air recirculation and works extending over a long period of time. Not least are furthermore the vibrations caused by the thermal engine, whereto operators are exposed during all the operations carried out on these lifting structures, when they are at a height .
PROBLEM AND SOLUTION
The object of the present invention is hence to propose a new-design work-vehicle which overcomes the above-mentioned drawbacks and which hence allows to operate in safe conditions both below and above the overhead power line, or laterally of the same, and which furthermore may be moved to the work area without noise or exhaust gases, so as to make the use thereof in tunnels healthier and safer and so as to make the use thereof next to inhabited areas devoid of disturbances.
This object is achieved by means of a work-vehicle having the features defined in the main claim enclosed herewith. The dependent claims define other preferred features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the work-vehicle of the present invention will in any case be more evident from the fol- lowing detailed description of a preferred embodiment of the same, which is provided here purely as an example and must hence not be interpreted as limiting the scope of the invention. Such embodiment is shown in the attached drawings, wherein:
fig. 1 is a schematic side view of the work-vehicle ac- cording to the present invention, which also shows the outline measure in millimetres of the vehicle in a transport position; fig. 2 is a front view of the work-vehicle of fig. 1 in a transport position;
fig. 3 is a schematic side view which illustrates the moving area of the platform and the useful work area in the longi- tudinal plane; and
fig. 4 comprises a front view and a side view of the work- vehicle of fig. 1 resting on tracks having the maximum inclination possible, in the transversal and longitudinal plane, respectively, which inclination is automatically compensated by the work-vehicle of the invention, which always keeps the trampling plane of the platform horizontal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The work-vehicle according to the present invention consists of a normal 2-axle railway vehicle 1. On the vehicle flat- car, and substantially in correspondence of an axle of the same, there is housed an adjustable assembly 2 mounted on a vertical- axis fifth wheel the lower portion of which is anchored to the plane of vehicle 1, so that adjustable assembly 2 may rotate at will along an arch of 360°. The constraint between the lower part of the fifth wheel and the vehicle consists of a hinge on a spherical joint; this allows - through a drive consisting of two independent hydraulic cylinders and a double inclinometer - to automatically maintain the lower fifth wheel in a horizontal plane, so that the operator may always work in a maximum comfort condition and in full safety. A third omnidirectional inclinometer for planarity control oversees the work of the two axial inclinometers which operate to bring the adjustable assembly 2 level .
Adjustable assembly 2 is furthermore provided with an arm 3 hinged thereto provided with a telescopic extension 3a so that arm 3 may be capable both of a longitudinal extension movement through its telescopic extension 3a, and of a rotation movement in a vertical plane with respect to adjustable assembly 2. Arm 3 may hence take up a series of work positions at a different in- clination and extension, between two limit positions represented in fig. 3 and consisting of a fully drawn-in horizontal home po- sition and of a fully extended, sub-vertical position of maximum height. Without the help of particular structural applications, in a fully automatic way, the electronic equipment management system furthermore allows - as can be seen again in fig. 3 - to work in the rear 180° up to a minimum height of about 2 metres from the track plane (vehicle flatcar height) , and hence much lower than the transport one, thus guaranteeing the opportunity to work comfortably even in particularly low tunnels.
On the free end of the telescopic extension 3a of arm 3 there is finally fastened, free to rotation along 180°, a work platform 4 provided with usual fall-preventing protection railings 5, provided with a collapsing-by-rotation device, so as to reduce the bulk in the transport position, if necessary (position shown in fig. 1 and 2 as FP) . Adjustable assemblies of this type, normally with hydraulic drives, are well-known in the art and allow to combine a remarkable degree of reliability, flexibility and speed of use in the different work positions, excellent manoeuvrability of movable platform 4 which can be made to rotate along 180°, and very limited bulk in a foldaway position. In order to reduce to zero the slight initial delay of the travel of the hydraulic orientation cylinder of the platform, due to the piloting of the locking valves mounted directly on the cylinders of the hydraulic parallelogram controlling platform planarity, at each work cycle the electronic unit managing the equipment if necessary resets the perfect horizontality of the trampling plane of the platform, always ensuring a safe position to all the operators who occupy it.
As a matter of fact, as shown in figs. 1 and 2, the entire system consisting of adjustable assembly 2, arm 3 with tele- scopic extension 3a and of platform 4, in a foldaway position is comprised within the outline of a railway vehicle measuring 2,5 x 4,3 m, with a height bulk of 2,8 m, hence making also road transport of this vehicle very easy, for the swift transfer thereof between various working sites.
In the maximum inclination and extension position of the telescopic extension 3a of arm 3, platform 4 can instead reach a height of about 7,5 metres from the track plane (useful work height 9,5 m) , when the centre of gravity of the movable platform lies on the vehicle vertical. Alternatively, in a slightly lowered position, at a height of platform 4 of about 6,5 metres from the track plane (useful work height 8,5 metres), platform 4 can keep a work position with a longitudinal or lateral range of 4,20 metres (useful work area 4,7 m) with respect to the vertical rotation axis of assembly 2, thus allowing to reach most comfortably all the possible work positions, both along the line and in the proximity of the shelves supporting the overhead power line and behind the shelves. Fig. 3 shows by the thin line the limit area of the positions which the platform can take up and by the thick line the corresponding useful work area for the operators; such areas are symmetrical for the entire arc of 360°, except for the rear portion of the vehicle where the particularly lowered position of the platform can be obtained only in correspondence of the rear area of the vehicle.
The work-vehicle of the invention hence allows to operate in a much larger work area compared to the one achievable through known-type work-vehicles. Despite this large widening of the covered work area, obtained through the use of adjustable assembly 2 with arm 3 and telescopic extension 3a, however, the work-vehicle of the present invention keeps the opportunity of reaching the various work positions through rectilinear move- ments, and hence in a way particularly convenient for the operator.
As a matter of fact, the movement of platform 4 can be actuated in the way usual for this type of adjustable arms, i.e. by driving one or more of the four types of actuations available (rotation of assembly 2, inclination of arm 3, extension of telescopic extension 3a and rotation of platform 4) in order to move the platform closer to the desired final position, with a typical movement which is called "saw-toothed" . However, according to a preferred feature of the invention, the work-vehicle is provided with a control and management unit of such actuations which enables the operator to obtain rectilinear movements of the platform according to axes X, Y and Z through an automatic interpolation of the different actuations of the machine by the control unit, in a way transparent to the operator. The operator hence has easy and safe control of the machine even when he must lead platform 4 in the proximity of obstacles; as a matter of fact, since said platform moves along rectilinear trajectories, he is able to foresee with much greater accuracy and in an entirely safe way, the path which the platform will follow during its movements compared to what occurs in traditional movable arms with "saw-toothed" movements.
This articulated solution of the work-vehicle of the invention hence enables the operator to effortlessly avoid the obstacle represented by the presence of the contact wires which prevent traditional work-vehicles to rise up to a convenient height for the maintenance or repair of suspension ropes, allowing to raise platform 4 along a suitable vertical trajectory moved outwards of the track by a measure sufficient to cause the platform not to interfere with the contact wires: thereby the operators can reach in full safety and with full visibility all the possible work positions on both sides of the overhead power line. Similar considerations apply when it is necessary to operate in the proximity of the supports, a position which can be reached and easily overtaken by the work-vehicle of the invention, so as to be able to access in a comfortable position also the rear part of the support, i.e. in a position which was fully unreachable with the work-vehicles of the prior art. The actuation safety of telescopic arm 3 and of platform 4 can be further increased by providing the vehicle of the present invention with automatic anti-collision devices (for example infra-red ones) which allow to avoid the collision between arm 3 or platform 4 and the overhead power line, blocking the movement of the arm when the minimum distance between said elements drops below the preset threshold value.
Finally, thanks to the fact that assembly 2 and therewith movable platform 4 - as already stated above - have an automatic horizontality control - regardless of the positions taken up by arm 3, and by vehicle 1 - the inclination problems of traditional work platforms is fully overcome, as clearly visible in fig. 4. In said traditional platforms, in fact, the same inclination as the track is reproduced, i.e. both the lateral one in curves and the longitudinal one in slopes, forcing the operator to work on an inclined plane, certainly not ideal to perform well and safely all the necessary operations . The solution offered by the work-vehicle of the invention allows instead to cancel the effect of the lateral or longitudinal inclination of vehicle 1, enabling the operator to always work on a horizontal plane, hence in conditions of maximum stability and safety.
With the above described lifting device the first part of the object of the invention has hence been fully achieved, i.e. that of enabling the operator to reach any point of the overhead power line comfortably and without any risks for his safety.
However, in order to fully reach such object and hence guarantee full safety for the operator not only from the point of view of his position on the platform, but also in connection with the environmental conditions in which he works, the work- vehicle of the present invention provides to use, instead of the conventional Diesel engine propulsion, a hybrid motorisation comprising at least one internal combustion engine and at least one electric motor powered by a series of batteries installed in the flatcar of vehicle 1.
As a matter of fact, the adoption of the hybrid motorisation allows the work-vehicle of the invention great flexibility in the choice of the propulsion most suitable to the different working conditions. In particular, the work-vehicle can move quickly on the railway during the macro-transfers from one work- ing site to the other using the internal combustion engine, preferably a high-efficiency, last-generation Diesel engine with reduced emissions. During the mini-transfers occurring instead within the working site while carrying the maintenance operations on the overhead power line, the work-vehicle can be con- veniently moved by the electric motor. As a matter of fact this type of motor allows to control better the position of the work- vehicle also for small backward-forward position adjustments or for continuous, low-speed transfers along the line. Moreover, the two vehicle axles are driven independently by the motors for the purpose of obtaining the minimum energy consumption in the various working conditions.
With this type of motorisation, during the maintenance operations all the sources of noise which may cause a nuisance to operators on the platform and to personnel on the ground, making them less attentive or preventing them from perceiving signals or voice communications, are completely abolished; nor are there emissions of harmful gases which make the working environment less healthy or simply less pleasant, inducing the operators to hasty repair works in order to escape more quickly the inconvenience .
Thanks to the proposed motorisation solution, in particular, it is possible to work, even for long periods of time, in poorly ventilated tunnels without any breathing problem due to the absence of fumes and particulate. The quietness of the work- vehicle with electric propulsion furthermore allows to work at night-time, even in the proximity of inhabited areas, creating a favourable condition for maintenance works which - during daytime - are made difficult by the intensity of railway traffic.
The battery pack that comes with the equipment consists of maintenance-free, latest-generation gel elements for traction use.
The recharging of the batteries which supply the electric motor can occur at three different times:
1 - recharge during transfers or outdoor works, during which the Diesel engine is used: as a matter of fact, in this phase the Diesel engine, in addition to supplying energy for the various movements, also provides to recharge the batteries;
2 - recharge during breaks, with Diesel engine: this condition is useful for example during lunch-break or at night, when the work-vehicle may be placed in an area where fumes and noise are not a nuisance. As a matter of fact, the control system which comes with the work-vehicle of the invention provides the opportunity to leave the vehicle on (with all movements interlocked at the highest safely level) until the batteries are suitably charged. The management of the recharge phases is fully automatic and continuously monitored, allowing to reach the ideal recharge level and then to halt automatically both the recharge process and the Diesel engine. The halt of the engine is furthermore provided also in case of technical failure;
3 - recharge with connection to the electric supply network: wherever an electric supply network is available the op- portunity of a direct recharge of the batteries is finally provided, with an automatic management identical to what has been described above concerning the recharge with Diesel engine.
In addition to the above described ordinary recharge systems, the work-vehicle of the invention also provides the oppor- tunity to recover kinetic energy, especially during braking phases, thereby allowing to regenerate - in the form of electric energy of the batteries - the energy normally transformed into heat and fully dissipated. Should the batteries be already fully charged and the vehicle face a downward slope, dissipation re- sistances are finally provided to be able to control speed through the electric motor.
In the preceding description only the innovative aspects of the work-vehicle of the invention have been illustrated, being intended that the machine has also all the other technical devices of traditional work-vehicles , necessary for the good operation of the vehicle and well-known to people skilled in the field, so that the description thereof can here be omitted for shortness sake.
However, it is understood that the invention must not be considered limited to the particular arrangement shown above, which represents only an exemplifying embodiment thereof, but that a number of variants are possible, all within the reach of a person skilled in the field, without departing from the scope of protection of the invention, as defined by the attached claims.