EP0692418B1

EP0692418B1 - Driving system for cableway installations of the type including carrying cables and hauling cables

Info

Publication number: EP0692418B1
Application number: EP95201878A
Authority: EP
Inventors: Erwin Oberhuber
Original assignee: HOELZL COSTRUZIONE FUNIVIE Srl
Current assignee: HOELZL COSTRUZIONE FUNIVIE Srl
Priority date: 1994-07-14
Filing date: 1995-07-08
Publication date: 1999-11-24
Anticipated expiration: 2015-07-08
Also published as: DE69513452T2; EP0692418A1; IT1276268B1; ATE186879T1; ITBZ940042A1; DE69513452D1; ES2139830T3; ITBZ940042A0

Abstract

A driving system for cableway installations comprises at least one pathway along which a respective car (4; 4, 4') moves, and a pair of parallel carrying cables (1; 1, 1') on which a carriage (5) of the car (4; 4, 4') moves slidably. The carrying cables (1; 1, 1') are located at opposite sides of the car (4; 4, 4'), at a reciprocal distance greater than the width of the car (4; 4, 4'). On the carriage (5) of the car (4; 4, 4'), in a position symmetrical with and in the proximity of the sides of the carriage (5), there are two pairs of freely rotatable compensation pulleys (11a, 12a, 11b, 12b). For each pathway there is a first section of hauling cable (6A; 60A, 60B) and a second section of hauling cable (6B; 60A', 60B'); the first section of hauling cable (6A; 60A, 60B) comprises two parallel branches (6a, 6b; 60a, 60b, 60c, 60d) extending from a first station (2) to the car (4; 4, 4') and located at a reciprocal distance greater than the width of the car (4; 4, 4'), and the second section of hauling cable (6B; 60A', 60B') comprises two parallel branches (6c, 6d; 60a', 60b', 60c', 60d') extending from a second station (3) to the car (4; 4, 4') and located at a reciprocal distance greater than the width of the car (4; 4, 4'). The first section of hauling cable (6A; 60A, 60B) is wound on the first pair of compensation pulleys (11a, 12a), and the second section of hauling cable (6B; 60A', 60B') is wound on the second pair of compensation pulleys (11b, 12b). <MATH>

Description

The present invention relates to a driving system for cableway installations of the type including carrying cables and hauling cables.
It is known that cableway installations are divided into two wide-ranging categories: "single cable" installations and "twin-cable" installations.
With the name of single-cable installations there are indicated those cableway installations wherein a single cable (or, as the case may be, a single pair of parallel cables) executes simultaneously both the function of carrying cable and the function of hauling cable. With the name of twin-cable installations there are, on the other hand, indicated those cableway installations with at least one, fixed, carrying cable and at least one, movable, hauling cable.
Single-cable installations have two main drawbacks with respect to twin-cable installations. In the first place, in a single-cable installation the carrying-hauling cable must have a sufficiently large diameter to support the weight of the car; this determines an increase in the weight of the masses in motion and an increase in the size of the driving system with respect to the case of a twin-cable installation, wherein the weight of the car is supported by the carrying cable and the hauling cable can thus have a reduced diameter. In the second place, the possibility of tensioning the carrying-hauling cable of a single-cable installation is always a great deal less than that of the carrying cable of a twin-cable installation. Twin-cable installations are thus frequently preferred over the single-cable type, in particular if cars of considerable dimensions and weight are contemplated.
Twin-cable installations are known that for each car and corresponding pathway between an upper station and a lower station comprise a single carrying cable or a twin carrying cable; the car is suspended from the carrying cable, either single or twin, through a cableway carriage, to which the car is in turn fastened through a suspension.
As is known, during their movement the cars are subjected to oscillations. Such oscillations are usually distinguished into longitudinal oscillations, when they take place in the vertical plane lying in the direction of forward movement of the car, and transversal oscillations, when they take place transversally to the direction of forward movement of the car (direction of the carrying cable).
With reference to longitudinal oscillations, the length of the suspension and the inclination of the carrying cable are particularly important. In fact, the presence of too short a suspension and of steep gradients of the carrying cable, it can happen that during the longitudinal oscillations the car can touch the carrying cable and/or the hauling cable, with consequent damage to both the car and the cables.
On the other hand, too long a suspension requires the construction of cableway stations that are unnecessarily tall, and thus substantial costs for civil engineering works and a frequently unacceptable environmental impact, particularly in the case of stations built high up in the mountains.
It is thus recommended that cars be built with short suspensions.
Tranversal oscillations in turn require the car to be made to approach the station at a very low speed.
In view of the described state of the art, the object of the present invention is that of providing a driving system for cableway installations of the type comprising carrying cables and hauling cables that allows the use of cars with suspensions of a limited length, and that is not affected by the problems caused by the oscillations of the cars.
According to the present invention, such object is achieved thanks to a driving system for cableway installations of the twin-cable type, comprising:

at least one pathway along which the respective car moves; and
for said at least one pathway, a pair of parallel carrying cables, on which a carriage for supporting the car moves slidably, and at least one hauling cable, characterized in that
said carrying cables are located at opposite sides of the car, at a reciprocal distance greater than the width of the car;
on the carriage of the car there are two pairs of freely rotatable compensation pulleys, each pair of pulleys comprising a first pulley and a second pulley located symmetrically in the proximity of the two sides of the carriage;
for said at least one pathway there is a first section of hauling cable and a second section of hauling cable, the first section of hauling cable comprising two parallel branches extending from a first station to the car and located at a reciprocal distance greater than the width of the car, and the second section of hauling cable comprising two parallel branches extending from a second station to the car and located at a reciprocal distance greater than the width of the car, said first section of hauling cable being wound on the first pair of compensation pulleys, and said second section of hauling cable being wound on the second pair of compensation pulleys.

Thanks to the fact that the distance between the two carrying cables and between the two branches of each section of hauling cable is greater than the width of the car, the car will be able to oscillate longitudinally even in the presence of a short suspension, without any danger of it going to touch the cables. Again thanks to the fact that the distance between the two carrying cables is greater than the width of the car, the transversal oscillations of the car are highly damped when approaching the stations; the speed at which the cars approach the stations does not therefore have to be reduced too much.
Moreover, thanks to the use of pairs of compensation pulleys, round which the hauling cable(s) are wound, an indirect and balanced connection is obtained of the hauling cable(s) of the car, which allows a uniform movement of the car to be obtained without any risk that, due to even small differences in the movement of the two branches of the hauling cable(s) or to their breakage, the large distance between the two abovementioned branches generates a dangerous twisting moment.
These and other features and advantages of the present invention will be made more evident by the following detailed description of two embodiments thereof, described as non-limiting examples with reference to the enclosed haulings, wherein:
Fig. 1 is a schematic plan view from above of a driving system according to the present invention for a cableway installation with one pathway, in a first operative condition;
Fig. 2 shows the driving system of Fig. 1, in a second operative condition;
Fig. 3 is a plan view from above of a car of the cableway installation of Fig. 1;
Fig. 4 is a front view of the car of Fig. 3;
Fig. 5 is a cross-sectional view taken along the line V-V of Fig. 3;
Fig. 6 is a diagrammatic plan view from above of a driving system according to the present invention for a cableway installation with two pathways, in a first operative condition;
Fig. 7 shows the driving system of Fig. 6, in a second operative condition;
Fig. 8 is a cross-sectional view taken along the line VIII-VIII of Fig. 6;
Fig. 9 is a cross-sectional view taken along the line IX-IX of Fig. 6.
There is shown in a diagrammatic manner in Figs. 1 and 2 a driving system according to the present invention for a cableway installation with one pathway, comprising a pair of parallel carrying cables 1 (represented with a continuous line), extending between two stations 2 and 3. In the example shown, station 2 is a driving station, located indifferently up the mountain or down in the valley; station 3 is a driven station.
The two carrying cables 1 are located at opposite sides of a car 4, at a reciprocal distance greater than the width of the car 4. The car 4 is provided in a known manner with a supporting carriage 5 (better visible in Fig. 3) slidably moving on the two carrying cables 1 through idle pulleys 50.
In the present case of a cableway installation with only one pathway, there is only one hauling cable 6, closed in upon itself to form a ring. The hauling cable 6 comprises a first pair of parallel branches 6a, 6b (represented with a dashed and dotted line) that extend from the station 2 to the car 4 and define a first section of hauling cable 6A, and a second pair of parallel branches 6c, 6d (represented by a line with dashes and two dots) that extend from the station 3 to the car 4 and define a second section of hauling cable 6B. The reciprocal distance between the two branches 6a, 6b, as well as the reciprocal distance between the two branches 6c, 6d, is greater than the width of the car 4. Thus, neither the carrying cables 1, nor the branches 6a-6d of the hauling cable 6 lie along the pathway of longitudinal oscillation of the car 4. The hauling cable 6 also comprises two further parallel branches 6e, 6f, that connect together the abovementioned branches 6a, 6b and 6c, 6d, respectively.
On the carriage 5 of the car 4 there are two pairs of pulleys, for example twin pulleys 11 and 12 located in the proximity of the two sides of the carriage 5 and each comprising two coaxial pulleys 11a, 11b and 12a, 12b, superimposed one above the other, and rotatable independently one from the other (Figs. 4 and 5). At the point where the branch 6a is joined with the branch 6b, the first section of hauling cable 6A is wound on the first pair of pulleys 11a and 12a; in a similar manner, at the point where the branch 6c is joined with the branch 6d, the second section of hauling cable 6B is wound on the second pair of pulleys 11b and 12b.
As shown in Figs. 1 and 2, at the station 2 there is a pair of driving pulleys 7 and 8 that are normally driven in an integral manner by the same driving shaft not shown, on which the branches 6a and 6b, respectively, of the hauling cable 6 are wound. In a similar manner, there is a pair of driven pulleys 9 and 10 at the station 3, on which the branches 6c and 6d, respectively, of the hauling cable 6 are wound.
The branches 6e and 6f of the hauling cable 6 extend from the exit of the driving pulleys 7 and 8 of the station 2 to the entry to the driven pulleys 9 and 10 of the station 3, in a direction parallel to the carrying cables 1, to connect the branch 6a of the section of hauling cable 6A to the branch 6c of the section of hauling cable 6B and the branch 6b of the section of hauling cable 6A to the branch 6d of the section of hauling cable 6B.
The two driven pulleys 9 and 10 can be displaced integrally along a direction parallel to the direction of the carrying cables 1, to ensure an adequate degree of tension of the hauling cable 6: the two pulleys 9 and 10 thus perform the twin function of transmission and tensioning. As an alternative, the two pulleys 9, 10 can be fixed, and the two driving pulleys 7 and 8 can be displaced integrally along said direction parallel to the direction of the carrying cables 1: the pulleys 9, 10 then perform only the function of transmission, while the tensioning function is performed by the driving pulleys 7, 8. It is also possible that both the two driven pulleys 9, 10, and the two driving pulleys 7, 8 can be displaced along the direction of the carrying cables.
Moreover, the two driving pulleys 7 and 8, that as has been said are normally integral, can be disconnected so that they can rotate independently one from the other, so that the hauling cable 6 can be made to slide along; this is made possible by the fact that, as has been said, the pulleys 11a and 12a on the carriage 5 of the car 4 can rotate in a manner independent from pulleys 11b and 12b, respectively. In this way, it is possible to vary the points of winding of the hauling cable 6 on the pulleys 11 and 12, at which points of winding the stress on the hauling cable 6 is at its maximum; it is thus possible to ensure a uniform wear of the hauling cable.
When the driving system is in operation, the simultaneous rotation of the pulley 7 in a clockwise direction and of the pulley 8 in an anti-clockwise direction determines the sliding action of the hauling cable 6 in the direction indicated by the arrows of Fig. 1; the car 4 slides along the carrying cables 1 in the direction of the station 2 (arrow A in Fig. 1). If the angular speed of rotation of the two pulleys 7 and 8 is exactly the same, and such pulleys have exactly the same radius, the sliding speed of the two branches 6a and 6b, as well as that of the two branches 6c and 6d, is the same; the twin pulleys 11 and 12 located on the car do not rotate on their own axis of rotation, as there is no relative sliding action of the pairs of parallel branches 6a, 6b and 6c, 6d of the hauling cable 6. If, on the other hand, the pulleys 7 and 8 do not rotate at exactly the same speed, or if they have a slightly different radius (for example, due to a different degree of wear of the races of the pulleys themselves), the sliding speed of the two branches 6a and 6b will not be the same: there will then be a rotation of the pulleys 11a and 12a on the respective axis of rotation in a clockwise or anticlockwise direction according to whether the branch 6a has a smaller or larger sliding speed with respect to that of the branch 6b; in a similar manner, the pulleys 11b and 12b will rotate in an anticlockwise or in a clockwise direction, respectively. The twin pulleys 11 and 12, making it possible for the pairs of parallel branches 6a, 6b and 6c, 6d of the hauling cable 6 to slide relatively to one another, allow a compensation to be made for the different sliding speed of the branches 6a and 6b of the hauling cable 6; for this reason the pulleys 11a, 11b, 12a, 12b are known as "compensation pulleys". It should be noted that in this way no twisting moment is applied to the car, as would instead be the case if the branches of the carrying cable were connected in a substantially fixed manner to the car. This is also true in the event of a breakage of the hauling cable: in this case, the hauling cable merely slips away from the carriage of the car, without any dangerous twisting moment being applied to the latter that could cause disastrous slippages of the carriage off the carrying cables.
In a similar manner, when the pulley 7 rotates in an anti-clockwise direction and, at the same time, the pulley 8 rotates in a clockwise direction, the hauling cable 6 slides in the direction indicated by the arrows in Fig. 2; the car 4 then slides along the carrying cables 1 in the direction of the station 3 (arrow B of Fig. 2). As in the previous case, the twin pulleys 11 and 12 allow a compensation to be made for any difference in the sliding speed of the parallel branches 6b and 6c of the hauling cable.
In Figs. 6 and 7 there is shown, in a diagrammatic manner, a driving system according to the invention for a cableway installation with two pathways. The installation comprises two pairs of carrying cables 1 and 1', one pair for each pathway, extending between two stations 2 and 3. The carrying cables of each pair 1 or 1' are parallel to each other, and are located at a reciprocal distance greater than the width of a respective car 4 or 4'. The cars 4 and 4' have a respective supporting carriage 5 (Fig. 3) slidably moving on the pair of carrying cables 1 or 1' through the idle pulleys 50.
As opposed to the previous case of an installation with only one pathway, there are two hauling cables 60 (represented by a dashed and dotted line) and 60' (represented by a line with dashes and two dots), both closed in upon themselves to form two rings. The first hauling cable 60 comprises a first pair of parallel branches 60a and 60b that extend from the station 2 to the car 4 and define a first section of hauling cable 60A for a first pathway, and a second pair of parallel branches 60c and 60d that extend from the station 2 to the car 4' and define a first section of hauling cable 60B for a second pathway. The second hauling cable 60' comprises in turn a first pair of parallel braches 60a' and 60b' that extend from the station 3 to the car 4 and define a second section of hauling cable 60A' for the first pathway, and a second pair of parallel branches 60c' and 60d' that extend from the station 3 to the car 4' and define a second section of hauling cable 60B' for the second pathway. The reciprocal distance between the parallel branches 60a, 60b; 60c, 60d; 60a', 60b'; 60c', 60d' is greater than the width of the cars 4 and 4'; thus, neither the carrying cables, nor the hauling cables lie within the paths of longitudinal oscillation of the cars.
On the carriage 5 of each of the cars 4 and 4' there are two pairs of pulleys, for example two twin pulleys 11 and 12 located in the proximity of the sides of the carriage; as in the previous case, each twin pulley comprises two pulleys, 11a, 11b and 12a, 12b, respectively, coaxial and rotatable independently one from the other (Figs. 4 and 5).
At the point where the branches 60a and 60b are joined, the hauling cable 60 is wound on the first pair of pulleys 11a and 12a of the car 4, and in a similar manner, at the point where the branches 60c and 60d are joined, the cable 60 is wound on the first pair of pulleys 11a and 12a of the car 4'. The hauling cable 60' is in turn wound, at the point where the branches 60a' and 60b' are joined, on the second pair of pulleys 11b and 12b of the car 4, and, at the point where the branches 60c' and 60d' are joined, on the second pair of pulleys 11b and 12b of the car 4'.
As is visible in Figs. 6 and 7, at the station 2 there is a twin driving pulley 13, two twin driven pulleys 14 and 15, and two single driven pulleys 16 and 17.
As shown in Fig. 8, the twin driving pulley 13 comprises two coaxial pulleys 13a and 13b made integral by a pair of tie rods 18. The pulley 13 is coupled, by means of a toothed joint 19, to a driving shaft 20; the rotary motion of the driving shaft 20 is thus transmitted to the pulley 13a, and this in turn transmits it to the pulley 13b. There are also two braking units 21, for the pulleys 13a and 13b, respectively. The single twin driving pulley 13 could be replaced by a pair of separate driving pulleys.
The twin driven pulleys 14 and 15 each comprise, in a manner altogether similar to the pulleys 11 and 12 on the cars 4 and 4', two superimposed coaxial pulleys freely rotatable one with the other.
At the station 2, the branch 60a of the hauling cable 60 is wound on the driven pulley 16 and on the lower pulley of the twin driven pulley 14, and the branch 60d is wound on the driven pulley 17 and on the lower pulley of the twin driven pulley 15; at the point where the branches 60a and 60d are joined, the hauling cable 60 is wound on the pulley 13a of the twin driving pulley 13. Again at the station 2, the branch 60b of the hauling cable 60 is wound on the upper pulley of the twin driven pulley 14, and the branch 60c is wound on the upper pulley of the twin driven pulley 15; at the point where the two branches 60b and 60c are joined, the hauling cable 60 is wound on the pulley 13b of the twin driving pulley 13.
At the station 3 there are two single driven pulleys 22 and 23, and three twin driven pulleys 24, 25 and 26.
As shown in Fig. 9, the twin driven pulley 26 comprises two coaxial superimposed pulleys 26a and 26b rotatable independently one from the other on a shaft 27. The twin driven pulley 26 can also be displaced along a direction parallel to the direction of the carrying cables to ensure a constant degree of tension of the hauling cables 60 and 60'; the twin driven pulley 26 is thus a tensioning pulley. As an alternative, the twin driven pulley 26 can be fixed, and the twin driving pulley 13 can be displaced in the direction of the carrying cables, or both the twin driven pulley 26 and the twin driving pulley 13 can be displaced in the direction of the carrying cables.
At the station 3, the branch 60a' of the hauling cable 60' is wound on the driven pulley 23 and on the lower pulley of the twin driven pulley 24, and the branch 60d is wound on the driven pulley 22 and on the lower pulley of the twin driven pulley 25; at the point where the two branches 60a' and 60d' are joined, the hauling cable 60' is wound on the pulley 26a of the twin tensioning pulley 26. Again at the station 3, the branch 60b' of the hauling cable 60' is wound on the upper pulley of the twin driven pulley 24, and the branch 60c' is wound on the upper pulley of the twin driven pulley 25; at the point where the branches 60b' and 60c' are joined, the hauling cable 60' is wound on the pulley 26b of the twin tensioning pulley 13.
When the driving system is in operation, the rotation in the anti-clockwise direction of the twin driving pulley 13 determines the sliding action of the two hauling cables 60 and 60' in the direction indicated by the arrows in Fig. 6; the car 4 slides along the pair of carrying cables 1 towards the station 3, while the car 4' slides along the carrying cables 1' toward the station 2. The rotation in a clockwise direction of the twin driving pulley 13 determines on the other hand the sliding action of the hauling cables 60 and 60' in the direction indicated in Fig. 7; the car 4 then slides along the pair of carrying cables 1 towards the station 2, while the car 4' slides along the carrying cables 1' toward the station 3.
In both cases, if the sliding speeds of the branches 60a and 60b (and thus of the branches 60c and 60d) of the hauling cable 60 are exactly the same one with the other, and the sliding speeds of the branches 60a' and 60b' (and thus of the branches 60c' and 60d') of the hauling cable 60' are also exactly the same one with the other, the twin pulleys 11 and 12 on the cars 4 and 4' do not rotate on their respective axis of rotation.
If, on the other hand, the two branches 60a and 60b (and thus the two branches 60c and 60d) of the hauling cable 60 do not slide along at the same speed, for example due to the fact that the two pulleys 13a and 13b of the twin driving pulley do not have exactly the same radius, the pulleys 11a and 12a of the first pair of pulleys on the cars 4 and 4' rotate on their respective axis of rotation, allowing a relative sliding action of the branches of the hauling cable 60 in order to compensate that difference in the sliding speeds; in this way the application of a twisting moment to the cars 4 and 4' is avoided. Something similar takes place if the two branches 60a' and 60'b (and thus the two branches 60c' and 60d') of the hauling cable 60 do not slide along at the same speed: such difference in the sliding speeds is compensated by the rotation of the pulleys 11b and 12b of the second pair of pulleys on the cars 4 and 4'.
Even in the case of breakage of one of the hauling cables, the latter simply slips away from the respective pair of pulleys on the cars, but it does not impart any dangerous twisting moment to the cars.
As has been said, the two pulleys 13a and 13b of the twin driving pulley 13 are normally made integral by the two tie rods 18, and rotate simultaneously. If the tie rods 18 are removed it is possible to disconnect the two pulleys 13a and 13b, making the pulley 13b independently rotatable with respect to the pulley 13a; it is thus possible to have the hauling cable 60 slip along so as to ensure its uniform wear. The slippage of the hauling cable 60' is, on the other hand, always possible, since the two pulleys 26a and 26b of the twin pulley 26 are normally independently rotatable from one another.
The driving system according to the present invention is suitable for installations wherein a braking system of the cars on the carrying cables is provided for or otherwise.

Claims

Driving system for cableway installations of the twin-cable type, comprising:

at least one pathway along which a respective car (4; 4, 4') moves; and

for said at least one pathway, a pair of parallel carrying cables (1; 1, 1'), on which a carriage (5) for supporting the car (4; 4, 4') moves slidably, and at least one hauling cable, (6; 60, 60'), characterized in that

said carrying cables (1; 1, 1') are located at opposite sides of the car (4; 4, 4'), at a reciprocal distance greater than the width of the car (4; 4, 4');

on the carriage (5) of the car (4; 4, 4') there are two twin compensation pulleys (11,12) each twin pulley being constituted by two superposed (11a,11b; 12a,12b) rotatably independent pulleys, said twin pulleys (11,12) being located symmetrically in the proximity of the two sides of the carriage (5);

for said at least one pathway there is a first section of hauling cable (6A; 60A, 60B) and a second section of hauling cable (6B; 60A', 60B'), the first section of hauling cable (6A; 60A, 60B) comprising two parallel branches (6a, 6b; 60a, 60b, 60c, 60d) extending from a first station (2) to the car (4; 4, 4') and located at a reciprocal distance greater than the width of the car (4; 4, 4'), and the second section of hauling cable (6B; 60A', 60B') comprising two parallel branches (6c, 6d; 60a', 60b', 60c', 60d') extending from a second station (3) to the car (4; 4, 4') and located at a reciprocal distance greater than the width of the car (4; 4, 4'), said first section of hauling cable (6A; 60A, 60B) being wound on the lower pulleys (11a,12a) of the twin compensation pulleys, and said second section of hauling cable (6B; 60A', 60B') being wound on the upper pulleys (11b,12b) of the twin compensation pulleys (11b, 12b).
Driving system according to claim 1, characterized in that the first pulleys (11a, 11b) of each pair of compensation pulleys (11a, 12a, 11b, 12b) are coaxial and superimposed one above the other to form a twin pulley (11), and the second pulleys (12a, 12b) of each pair of compensation pulleys (11a, 12a, 11b, 12b) are also coaxial and superimposed one above the other to form a further twin pulley (12).
Driving system according to claim 1 or 2 and comprising one pathway only, characterized in that:

said first section of hauling cable (6A) and said second section of hauling cable (6B) are connected to form a single ring-shaped hauling cable (6);

said two branches (6a, 6b) of the first section of hauling cable (6A) are wound on two respective driving pulleys (7, 8), respectively, located in said first station (2) and normally connected so as to be able to rotate integrally;

said two branches (6c, 6d) of the second section of hauling cable (6B) are wound on two respective driven pulleys (9, 10), respectively, located in said second station (3).
Driving system according to claim 3, characterized in that said two driven pulleys (9, 10) can be integrally displaced in the direction of the carrying cables (1) to allow the hauling cable (6) to be put under tension.
Driving system according to claim 4, characterized in that said two driving pulleys (7, 8) as well can be integrally displaced in the direction of the carrying cables (1) to allow, in combination with the two driven pulleys (9, 10), the hauling cable to be put under tension.
Driving system according to claim 3, characterized in that said two driving pulleys (7, 8) can be integrally displaced in the direction of the carrying cables (1) to allow the hauling cable (6) to be put under tension.
Driving system according to any of the claims from 3 to 6, characterized in that said two driving pulleys (7, 8) normally connected to rotate integrally can be disconnected so as to rotate independently one from the other, to allow the sliding action of the hauling cable (6).
Driving system according to claims 1 or 2 and comprising:

two pathways;

for each pathway, a respective pair of substantially parallel carrying cables (1, 1') on which the carriage of a respective car (4, 4') moves slidably, characterized in that:

the carrying cables (1, 1') of each pathway are placed at opposite sides of the respective car (4, 4') at a reciprocal distance greater than the width of said respective car (4, 4');

the first section of hauling cable (60A) of one pathway, extending from the first station (2) to the respective car (4), is connected to the first section of hauling cable (60B) of the other pathway, extending from the first station (2) to the respective car (4'), to form a first ring-shaped hauling cable (60A), and the second section of hauling cable (60A') of one pathway, extending from the second station (3) to the respective car (4), is connected to the second section of hauling cable (60B') of the other pathway, extending from the second station (3) to the respective car (4'), to form a second ring-shaped hauling cable (60');

the first hauling cable (60) is wound on at least one driving pulley (13) located in said first station (2), and the second hauling cable is wound on driven pulleys (22-26) located in said second station (3).
Driving system according to claim 8, characterized in that said at least one driving pulley (13) is a twin-pulley comprising two superimposed coaxial driving pulleys (13a, 13b) normally connected to rotate integrally.
Driving system according to claim 9, characterized in that a first driving pulley (13a) of the twin driving pulley (13) is coupled with a driving shaft (20), and a second driving pulley (13b) of the twin driving pulley (13) is made integral with the first driving pulley (13a) by means of tie rods (18).
Driving system according to claim 9 or 10, characterized in that the two driving pulleys (13a, 13b) of the twin driving pulley (13) can be disconnected to allow the sliding action of the first hauling cable (60).
Driving system according to any of the claims from 8 to 11, characterized in that said twin driving pulley (13) can be displaced in the direction of the carrying cables (1, 1') to allow the two hauling cables (60, 60') to be put under tension.
Driving system according to any of the claims from 8 to 12, characterized in that said driven pulleys (22-26) located in the second station (3) comprise at least one twin driven pulley (26) comprising two coaxial superimposed pulleys (26a, 26b) rotatable independently one from the other, said twin driven pulley (26) being displaceable in the direction of the carrying cables (1, 1') to allow the two hauling cables (60, 60') to be put under tension.
Driving system according to claim 13, characterized in that said driven pulleys located in the second station (3) comprise three twin driven pulleys (24-26), each comprising two coaxial superimposed pulleys rotatable independently one from the other, and two single driven pulleys (22, 23).
Driving system according to any of the claims from 8 to 14, characterized in that it comprises further driven pulleys (14-17) located in said first station (2).
Driving system according to claim 15, characterized in that said further driven pulleys (14-17) comprise two twin pulleys (14, 15), each comprising two coaxial superimposed pulleys rotatable independently one from the other, and two single driven pulleys (16, 17).