Cable transport system with two constant-force safety brakes that can be actuated selectively or simultaneously

Abstract

The invention relates to a cable transport system in which the pulley (10) is mechanically braked by friction, selectively or simultaneously, by a first safety brake (F1) capable of applying a first constant predetermined braking torque and a second safety brake (F2) capable of applying a second constant predetermined braking torque. A control unit (14) controls these two safety brakes (F1, F2), after receiving an emergency stop command (O1), according to a parameter representative of a mechanical torque (CM) transmitted to the pulley (10) by a drive system (12).

Description

[0001] DESCRIPTION

[0002] TITLE: Cable transport installation with two safety brakes with constant forces and which can be activated selectively or simultaneously

[0003] Technical field of the invention

[0004] The present invention relates to a cable transport installation comprising:

[0005] - a tractor carrying cable arranged in a closed loop,

[0006] - at least one rotatably mounted pulley applying a longitudinal force to the cable for its running movement,

[0007] - a plurality of vehicles attached to the cable,

[0008] - a motorization system transmitting a mechanical torque to the pulley to set it in rotation and generate said longitudinal force, the motorization system comprising at least one electric motor,

[0009] - a first safety brake cooperating by friction with the pulley, varying between an inactive state in which the first safety brake allows free rotation of the pulley and an active state in which the first safety brake mechanically brakes the pulley by friction,

[0010] - a second safety brake cooperating by friction with the pulley, varying between an inactive state in which the second safety brake allows free rotation of the pulley and an active state in which the second safety brake mechanically brakes the pulley by friction,

[0011] - a control unit controlling the motorization system and the safety brakes and capable of receiving emergency stop orders.

[0012] Vehicles are seats and / or cabins, intended for the transport of people or material between two points served by the cable transport installation.

[0013] State of the art

[0014] Figure 1 shows in a simplified manner the essential elements of a station of a known example of a cable transport installation.

[0015] Thus, cable transport installations generally include a pulley 1 transferring a mechanical torque to the cable in order to ensure its movement. This mechanical torque can be resistant or driving, depending on the gradient of the line and depending on the load on board the vehicles on the ascending track and the load on board the vehicles on the descending track. The pulley is itself driven by a motorization system which includes in series a gearbox 2, generally with an angle transmission, and an electric motor 3. Cable transport installations are always equipped with braking means. Most of the time, these braking means consist of three systems: an electric braking system, a service braking system identified by the reference 4, a safety braking system.

[0016] The electric braking system is provided by suitable control of the electric motor, particularly when normal deceleration or a normal stop with reduced deceleration is required in service. The electric braking system uses the service braking system 4 when the cable stops.

[0017] The service braking system 4 is a caliper brake, mechanically ensuring by friction a braking torque on a disc coupled to the rotor of the electric motor 3.

[0018] The safety braking system comprises two safety brakes 5, 6, each having a caliper mechanically applying by friction a braking torque directly to the pulley.

[0019] In normal operation, the service braking system 4 is designed to ensure deceleration of the cable, even under the most severe conditions of slope or load, within the range of values ​​imposed by administrative regulations, namely between 0.5 m / s 2 and 1.25 m / s 2 . The service braking system 4 is used in emergency situations, upon receipt of an emergency stop command from a human-machine interface or an automatic online failure detection device. The deceleration is then significantly greater than the deceleration obtained, under normal conditions, by the electric braking system.

[0020] The safety braking system is used in the event of a failure of the service braking system 4. It is an additional safety element in the event of a serious problem with the cable transport installation. The safety braking system is designed to ensure deceleration of the cable, even under the most severe conditions of gradient or load, within the range of values ​​imposed by administrative regulations, namely between 0.5 m / s 2 and 1.25 m / s 2 .

[0021] The braking force required to achieve such decelerations depends on the line load and its distribution between the ascending and descending tracks. If the vehicles are loaded along the ascending track, the required braking force is smaller than when the vehicles are loaded along the descending track. In long and / or very steep cableway installations, it is sometimes not possible to find settings for the service braking system and the safety braking system that allow the deceleration requirements contained between 0.5 m / s 2 and 1.25 m / s 2for all load conditions. Figure 2 illustrates this problem of the state of the art. It represents the braking torque applied to the pulley (in kNm) on the ordinate as a function, on the abscissa, of the deceleration of the cable (in m / s2), for 4 different load states of the vehicles: curve P1 corresponds to a load state indicated as “0 / 100”, which means that 0 vehicles on the ascending track carry no load, while 100% of the vehicles on the descending track carry their maximum loads, curve P2 corresponds to a load state indicated as “100 / 100”, which means that 100% of the vehicles on the ascending track carry their maximum loads and 100% of the vehicles on the descending track carry their maximum loads, curve P3 corresponds to a load state indicated as “0 / 0”, which means that 0 vehicles on the ascending track carry no load and 0 vehicles on the descending track carry no load,curve P4 corresponds to a load state indicated as “100 / 0”, which means that 0 vehicles in the descending lane are carrying a load, while 100% of the vehicles in the ascending lane are carrying their maximum loads.

[0022] The vertical lines passing through the values ​​X1 and X2 indicate the extreme values ​​of the deceleration range authorized by the administrative regulations, X1 being equal to 0.5 m / s 2 and X2 being equal to 1.25 m / s 2 .

[0023] Figure 2 illustrates that it is not possible to find an ordinate value (i.e. a braking torque value applied to the pulley (in kNm) by the service or safety braking system) for which all curves P1, P2, P3 and P4 are jointly included between X1 and X2.

[0024] In this case, it is typically necessary to install additional inertias (rotating masses) to reduce the influence of the load on board the vehicles.

[0025] This type of installation is not entirely satisfactory. First of all, the separate presence of a service braking system and a safety braking system makes the solution complex and expensive.

[0026] On the other hand, the use of a service braking system acting at the level of the electric motor involves high operating temperatures, high rotation speeds, and high wear rates of the friction pads; thus the service braking system is not totally reliable and involves a high level of maintenance.

[0027] Furthermore, the sometimes necessary use of additional inertias is not satisfactory because it represents losses of efficiency, the presence of unnecessary parts and involves adjustments on a case-by-case basis. As the safety braking system is used in the event of failure of the service braking system 4, the transition from one to the other may take a certain amount of time, in addition to the additional time resulting from the failure itself of the service braking system, and this may involve excessively long emergency braking which does not meet the aforementioned deceleration requirements set by the administrative regulations.

[0028] Finally, the total braking torque likely to be applied if the service braking system and the safety braking system were to inadvertently become simultaneously operational would imply a deceleration level that is significantly too high, typically of the order of 2.5 m / s. 2, which would be dangerous for people on board vehicles. This type of risk must be managed by additional means, which increases the complexity, cost and unreliability of known transport facilities.

[0029] Document FR2904594 describes an alternative solution, in which the safety brake system comprises two independent brakes, each capable of braking the transport installation according to a deceleration level contained within the range defined by administrative regulations. A speed sensor delivers an acquisition signal representative of the running speed of the cable. Each of the brakes is complex and expensive, because each includes a pressure regulator, in order to generate pressure forces and therefore braking torques that can be adjusted and varied as desired over time. The control unit transmits first control signals to the first brake, these being modulated to control the speed of the cable according to a first predetermined deceleration setpoint curve activated by the braking order.At the same time, the control unit transmits second control signals to the second brake, these being modulated to control the speed of the cable according to a second predetermined deceleration setpoint curve activated by the braking order, the instantaneous value of the second setpoint curve being greater, at each instant, than the value of the first setpoint curve.

[0030] However, once again, this type of transport installation is complex and expensive due to the nature of emergency brakes requiring modulation, adjustment and control means. It also results in a lack of reliability due to the complexity and number of mechanical, electrical and software means involved.

[0031] Subject of the invention

[0032] The present invention aims to provide a cable transport installation which is simple, economical, robust and reliable.

[0033] This aim can be achieved by providing a cable transport installation comprising: a hauling carrier cable arranged in a closed loop, at least one rotatably mounted pulley applying a longitudinal force to the cable for its running movement, a plurality of vehicles attached to the cable, a motorization system transmitting a mechanical torque to the pulley for its rotation and the generation of said longitudinal force, the motorization system comprising at least one electric motor, a first safety brake cooperating by friction with the pulley, varying between an inactive state in which the first safety brake allows free rotation of the pulley and an active state in which the first safety brake mechanically brakes the pulley by friction by transmitting to the pulley a first braking torque having a first predetermined constant value, a second safety brake cooperating by friction with the pulley,varying between an inactive state in which the second safety brake allows free rotation of the pulley and an active state in which the second safety brake mechanically brakes the pulley by friction by transmitting to the pulley a second braking torque having a second predetermined constant value, a control unit configured to: o receive at least one emergency stop command, o receive an acquisition signal whose value is representative of the evolution over time of said mechanical torque, o transmit control signals to the motorization system, o transmit first control signals to the first safety brake in order to place the first safety brake selectively in its active state or in its inactive state, o transmit second control signals to the second safety brake in order to place the second safety brake selectively in its active state or in its inactive state,the first control signals and the second control signals emitted by the control unit after the emergency stop order has been received by the control unit being a function of the value taken by the acquisition signal at the time of receipt of the emergency stop order.,

[0034] Such a cable transport installation is simple, economical, robust and reliable. Indeed, with this organization, it is no longer necessary to use a service braking system as was the case in the state of the art presented previously. It also makes it possible to avoid any recourse to additional inertias, even in the context of long and / or steep installations, because it is sufficient to dimension the first safety brake and the second safety brake appropriately. In addition, any risk of seeing a deceleration applied beyond 1.25 m / s is excluded. 2. Furthermore, the very nature of the two safety brakes makes them economical, reliable and robust.

[0035] Some preferred but not limiting aspects are as follows.

[0036] The control signals transmitted to the motorization system and emitted by the control unit, after receiving the emergency stop order, are a function of the value taken by the acquisition signal at the time of receiving the emergency stop order. This allows simple management of the electric motor and the safety brakes. For example, if the acquisition signal is below a certain threshold, the control signals will be modulated so that the slowing down and stopping of the installation is operated solely by the electric motor, without action of the safety brakes. Conversely, above this threshold, the control signals will be modulated so that the electric motor does not intervene in the transmission of a braking torque to the pulley, leaving this operation to the exclusive control of at least one of the two safety brakes, or even both.

[0037] The value of the acquisition signal is representative, at each instant, of the electrical intensity consumed by the electric motor of the motorization system. These provisions allow simple, reliable and economical management by the control unit, eliminating the need for another type of sensor.

[0038] The control unit may place the cable transport installation, after receiving the emergency stop order, among:

[0039] - a first operating mode in which a safety brake chosen from the first safety brake and the second safety brake occupies its active state and the other safety brake from the first safety brake and the second safety brake occupies its inactive state, only one from the first braking torque and the second braking torque being transmitted to the pulley, the control unit automatically placing the cable transport installation in the first operating mode when the following first condition is verified: the value taken by the acquisition signal at the time of receipt of the emergency stop order is between a low threshold and a high threshold, predetermined and recorded in a memory of the control unit,

[0040] - a second operating mode in which the first safety brake is in its active state and simultaneously the second safety brake occupies its active state, the first braking torque and the second braking torque being jointly transmitted to the pulley, the control unit automatically placing the cable transport installation in the second operating mode when the following second condition is verified: the value taken by the acquisition signal at the time of receipt of the emergency stop order is strictly greater than the predetermined high threshold. These provisions guarantee that the cable transport installation is reliable, economical and robust.Safety braking is achieved by simply controlling the two safety brakes between their active and inactive states, to adapt the braking torque applied to the pulley to the exact requirement in real time and according to the load conditions and the load distribution between the ascending and descending lines. The first operating mode also eliminates the risk of exerting excessive resistive torque and avoids the risk of excessive deceleration, which could otherwise be dangerous. This also avoids unnecessary wear on the safety brakes by operating them selectively if possible, i.e. when the load to be stopped is not too high.

[0041] The control unit is configured so as to automatically place the cable transport installation, after receiving the emergency stop order, in a third operating mode in which the first safety brake is in its inactive state and simultaneously the second safety brake occupies its inactive state, when the following third condition is verified: the value taken by the acquisition signal at the time of receiving the emergency stop order is strictly lower than the predetermined low threshold.

[0042] These provisions ensure that the cable transport installation is reliable, economical and robust. Safety braking is carried out by simply controlling the two safety brakes between their active and inactive states, to adapt the braking torque applied to the pulley to the exact requirement in real time and according to the load conditions and the load distribution between the ascending and descending lines. The third operating mode avoids unnecessary use of safety brakes when the simple electric motor, through appropriate control, is able to achieve the deceleration required for emergency braking, typically when the load is not very heavy or is mainly present on the vehicles of the ascending line. This also avoids unnecessary wear on the safety brakes by not operating them if it is not necessary.

[0043] In the third operating mode, the control unit transmits, after receiving the emergency stop command, control signals to the motorization system modulated so that the electric motor transmits to the pulley a resistive mechanical torque regulated over time so that the electric motor carries out a control of the running speed of the cable according to a predetermined deceleration setpoint curve recorded in a memory of the control unit, the deceleration setpoint curve being activated by said emergency stop command. This has the advantages already presented in connection with the presentation of the third operating mode, while ensuring that the comfort of the passengers is very good by imposing a deceleration speed low enough for a pleasant feeling.

[0044] The first predetermined constant value of the first braking torque for which the first safety brake is sized, the second predetermined constant value of the second braking torque for which the second safety brake is sized, the predetermined high threshold and the predetermined low threshold are all four configured so that the deceleration of the cable is, after receipt of the emergency stop order, between 0.5 m / s 2 and 1.25 m / s 2 . It follows that the mere presence of the two safety brakes allows the cable transport installation to meet the requirements of the administrative regulations, very advantageously avoiding the need for a service braking system as was the case in the state of the art presented in Figure 1, for reasons of reliability, cost, simplicity and robustness.

[0045] The cable transport installation comprises at least a first human-machine interface and at least one automatic failure detection device, the emergency stop order being issued by an element chosen from the human-machine interface and the automatic failure detection device. These provisions ensure rapid transmission of an emergency stop order by a person, typically the personnel responsible for boarding or disembarking vehicles, or by a safety sensor such as, for example, a sensor detecting a derailment or any other failure.

[0046] The cable transport installation comprises a second human-machine interface allowing a user to generate a braking order if a slowing down or stopping of the cable is desired by the user, the control unit being able to receive said braking order, which is distinct from the emergency stop order; after receiving said braking order, the control unit transmits to the motorization system control signals configured so that the electric motor transmits to the pulley a resistant mechanical torque suitable for carrying out said slowing down or stopping of the cable, the first safety brake and the second safety brake both being in the inactive state. These provisions guarantee rapid transmission of a braking stop order by a person, typically the personnel responsible for re-boarding vehicles or disembarking.These provisions also ensure that the cable transport installation is reliable, economical and robust. Normal braking, as distinct from emergency braking, is achieved by simply controlling the two safety brakes to their inactive state and simply controlling the electric motor to adapt the braking torque applied to the pulley to the exact requirement in real time and according to the load conditions and the load distribution between the ascending and descending lines. Unnecessary use of safety brakes is avoided when the simple electric motor, through appropriate control, is able to achieve the deceleration required for normal braking. This also avoids unnecessary wear on the safety brakes by not operating them if necessary.

[0047] The control unit is configured so that during a first phase and a second successive phase in which the cable transport installation is placed in the first operating mode after receiving respectively a first emergency stop order and a second consecutive emergency stop order, the control unit:

[0048] - places during the first phase, the first safety brake in the active state and the second safety brake in the inactive state,

[0049] - places during the second phase, the first safety brake in the inactive state and the second safety brake in the active state.

[0050] These provisions ensure alternation between the safety brakes used during successive emergency braking, in order to obtain uniform wear of the two safety brakes over time, and reducing the need for inspection and maintenance.

[0051] The first safety brake and the second safety brake are identical, circumferentially offset from each other around the axis of rotation of the pulley, the first predetermined constant value of the first braking torque being equal to the second predetermined constant value of the second braking torque.

[0052] These provisions allow for simplification of construction and management of parts, while reducing costs.

[0053] The first safety brake is configured so that the first predetermined constant value of the first braking torque is between 220 and 330 kNm and the second safety brake is configured so that the second predetermined constant value of the second braking torque is between 220 and 330 kNm.

[0054] These provisions ensure that the safety brakes are capable of emergency braking of all transport installations whose specifications are currently known in terms of transport capacity, gradient and line length.

[0055] Each of the first safety brake and the second safety brake comprises at least one braking member including a two-jaw caliper and two friction pads respectively secured to the two jaws, the friction pads varying, by relative movement between the jaws, between a first configuration where the friction pads do not exert friction forces on the pulley and a second configuration in which the friction pads exert friction forces on the pulley. These arrangements allow the safety brakes to be economical and reliable, and simple in terms of maintenance.

[0056] Each braking device comprises an automatic return element such as a spring or a fixed load, permanently biasing the friction pads towards the second configuration, and a hydraulic pressure supply opposing the action of the return element to bias the friction pads towards the first configuration only when hydraulic pressure is applied. These arrangements enable the safety brakes to be economical and reliable, and simple to maintain. They are also safe, because in the event of failure of the hydraulic pressure supply, the braking torques are automatically applied to stop the running of the cable and the operation of the cable transport installation.

[0057] Summary description of the drawings

[0058] Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the appended drawings in which:

[0059] [Fig. 1] Figure 1, already described, represents in a simplified manner the essential elements of a station of a known example of a cable transport installation.

[0060] [Fig. 2] Figure 2, already described with reference to the state of the art, represents, for an example of a transport installation according to the state of the art, the braking torque applied to the pulley (in kNm) on the ordinate as a function, on the abscissa, of the deceleration of the cable (in m / s2), for 4 different load states of the vehicles.

[0061] [Fig. 3] Figure 3 shows in a simplified manner the essential elements of a station of an example of a cable transport installation according to the invention.

[0062] [Fig. 4] Figure 4 represents, for the example of figure 3, the braking torque applied to the pulley (in kNm) on the ordinate as a function, on the abscissa, of the deceleration of the cable (in m / s2), for 4 different load states of the vehicles.

[0063] [Fig. 5] The figure represents by block diagram the essential elements already visible in figure 3 and their interactions.

[0064] [Fig. 6] Figure 6 shows a flowchart of operating steps of the cable transport installation of Figures 3 and 5.

[0065] Detailed description

[0066] In Figures 3 to 6 and in the remainder of the description, the same references represent identical or similar elements. In addition, the different elements are not shown to scale so as to enhance the clarity of the figures. Furthermore, the different embodiments and variants are not mutually exclusive and can be combined with each other.

[0067] With reference to figures 3 and 5, a cable transport installation comprises a tractor carrier cable arranged in a closed loop, at least one rotatably mounted pulley 10 applying a longitudinal force to the cable for its running movement and a plurality of vehicles attached to the cable.

[0068] Vehicles are seats and / or cabins, intended for the transport of people or material between two points served by the cable transport installation.

[0069] The length and gradient of the cable depends on the terrain on which the transmission facility is built and the distance between the lower and upper stations.

[0070] The cable transport installation comprises a motorization system 12 transmitting a mechanical torque CM to the pulley 10 for its rotation and the generation of the longitudinal force. The motorization system comprises at least one electric motor. The transmission between the motorization system 12 and the pulley 10 can be direct, the rotor of the electric motor being directly coupled to the pulley 10, or indirect by means of the interposition of a gearbox.

[0071] The cable transport installation comprises a first safety brake F1 cooperating by friction with the pulley 10. The first safety brake F1 varies between an inactive state in which the first safety brake F1 allows free rotation of the pulley 10 and an active state in which the first safety brake F1 mechanically brakes the pulley 10 by friction by transmitting to the pulley 10 a first braking torque having a first predetermined constant value.

[0072] The cable transport installation also comprises a second safety brake F2 cooperating by friction with the pulley 10. The second safety brake F2 varies between an inactive state in which the second safety brake F2 allows free rotation of the pulley 10 and an active state in which the second safety brake F2 mechanically brakes the pulley 10 by friction by transmitting to the pulley 10 a second braking torque having a second predetermined constant value.

[0073] The first safety brake F1 applies a first friction force to the pulley 10. The second safety brake F2 applies a second friction force to the pulley 10. The first predetermined constant value of the first braking torque depends on the first friction force and the distance separating the point of application of the first force and the center of rotation of the pulley 10. The second predetermined constant value of the second braking torque depends on the second friction force and the distance separating the point of application of the second force and the center of rotation of the pulley 10.

[0074] The cable transport installation comprises a control unit 14 configured to receive at least one emergency stop order 01, to receive an acquisition signal SA whose value is representative of the evolution over time of the mechanical torque CM transmitted to the pulley 10 by the motorization system 12, to transmit control signals SP to the motorization system 12, to transmit first control signals SC1 to the first safety brake F1 in order to place the first safety brake F1 selectively in its active state or in its inactive state, and to transmit second control signals SC2 to the second safety brake F2 in order to place the second safety brake F2 selectively in its active state or in its inactive state.

[0075] The first control signals SC1 and the second control signals SC2 emitted by the control unit 14 after the reception of the emergency stop order 01 by the control unit 14 depend directly on the value taken by the acquisition signal SA at the time of reception of the emergency stop order 01 by the control unit 14.

[0076] The control signals SP transmitted to the motorization system 12 and emitted by the control unit 14, after receipt of the emergency stop order 01, are a function of the value taken by the acquisition signal SA at the time of receipt of the emergency stop order 01 by the control unit 14.

[0077] Preferably, the value of the acquisition signal SA is representative, at each instant, of the electrical intensity consumed by the electric motor of the motorization system 12. However, the value of the acquisition signal SA may be representative, at each instant, of another parameter dependent on the mechanical torque CM, such as, for example, the load on board the vehicles and / or the speed of the cable.

[0078] According to one embodiment, from an initial situation SI in which the transport installation is in a normal stability regime where the cable runs at a normal speed, the control unit 14 is capable of placing the cable transport installation, after receiving the emergency stop order 01, by a circumstantial modulation of the first control signals SC1 and the second control signals SC2, among:

[0079] - a first operating mode in which a safety brake chosen from the first safety brake F1 and the second safety brake F2 occupies its active state and the other safety brake from the first safety brake F1 and the second safety brake F2 occupies its inactive state, only one from the first braking torque and the second braking torque being transmitted to the pulley 10, the control unit 14 automatically placing the cable transport installation in the first operating mode when the following first condition C1 is verified: the value taken by the acquisition signal SA at the time of receipt of the emergency stop order 01, is between a low threshold and a high threshold, predetermined and recorded in a memory of the control unit 14,

[0080] - a second operating mode in which the first safety brake F1 is in its active state and simultaneously the second safety brake F2 occupies its active state, the first braking torque and the second braking torque being jointly transmitted to the pulley 10, the control unit 14 automatically placing the cable transport installation in the second operating mode when the following second condition C2 is verified: the value taken by the acquisition signal SA at the instant of receipt of the emergency stop order 01 is strictly greater than the predetermined high threshold.

[0081] Step E5 corresponds to the reception of the emergency stop order 01 by the control unit 14, which in a step E6 determines the value which was taken by the acquisition signal SA in order to be representative of the mechanical torque transmitted to the pulley 10 at the instant when the emergency stop order 01 was received. Then in a step E7, the control unit compares this value to the high and low thresholds. If the first condition 01 is verified, then the first operating mode is adopted in a step E8. If the second condition 02 is verified, then the second operating mode is adopted in a step E9.

[0082] The control unit 14 is configured so as to automatically place the cable transport installation, after receiving the emergency stop order 01, in a third operating mode in which the first safety brake F1 is in its inactive state and simultaneously the second safety brake F2 occupies its inactive state, when the third condition 03 is verified: the value taken by the acquisition signal SA at the time of receipt of the emergency stop order 01 is strictly lower than the predetermined low threshold. If in step E7 it is noted by the control unit 14 that the value of the acquisition signal SA is lower than the low threshold, then the third condition 03 is verified and the control unit 14 places the transport installation in the third operating mode in a step E10.

[0083] In the third operating mode, it is then possible to provide that the control unit 14 transmits, after receiving the emergency stop order 01, control signals SP to the motorization system 12 modulated so that the electric motor transmits to the pulley 10 a resistive mechanical torque CM regulated over time so that the electric motor carries out a control of the running speed of the cable according to a predetermined deceleration setpoint curve recorded in a memory of the control unit 14, the deceleration setpoint curve being activated by receiving the emergency stop order 01.

[0084] Alternatively, depending on the load, the slope and the expected deceleration speed, it is possible to provide that in the third operating mode, after receiving the emergency stop command 01, such control signals SP are not transmitted, and in this particular case, the control unit 14 will wait for the stop by simple mechanical inertia without resorting to a resistive mechanical torque applied by the electric motor for this purpose.

[0085] According to a non-limiting embodiment, the first predetermined constant value of the first braking torque for which the first safety brake F1 is dimensioned, the second predetermined constant value of the second braking torque F2 for which the second safety brake is dimensioned, the predetermined high threshold and the predetermined low threshold are all four configured so that the deceleration of the cable is, after receipt of the emergency stop order 01, between 0.5 m / s 2 and 1.25 m / s 2 .

[0086] With reference to Figure 5, the cable transport installation comprises at least a first human-machine interface 16 and at least one automatic failure detection device 18, the emergency stop order 01 being issued by an element chosen from the human-machine interface 16 and the automatic failure detection device 18. These arrangements guarantee rapid transmission of an emergency stop order 01 by a person, typically the personnel responsible for re-boarding or disembarking the vehicles, or by a safety sensor such as for example a sensor detecting a derailment or any other failure.

[0087] The cable transport installation comprises a second human-machine interface 20 allowing a user to generate a braking order 02 if a slowing down or a stopping of the cable is desired by the user, the control unit 14 being able to receive this braking order 02, which is distinct from the emergency stop order 01; after receiving the braking order 02, the control unit 14 transmits to the motorization system 12 control signals SP configured so that the electric motor transmits to the pulley 10 a resistant mechanical torque adapted to achieve this slowing down or this stopping of the cable, the first safety brake F1 and the second safety brake F2 both being in the inactive state thanks to a circumstantial modulation of the first control signals SC1 and the second control signals SC2.

[0088] From the initial situation SI, step E1 corresponds to the reception of the braking order 02 by the control unit 14, which transmits to the motorization system 12 control signals SP configured so that, in a step E2, the electric motor transmits to the pulley 10 a resistive mechanical torque ensuring the slowing down corresponding to what is expected following the transmission of the braking order 02.

[0089] The control unit 14 is configured so that during a first phase and a second successive phase in which the cable transport installation is placed in the first operating mode after receiving respectively a first emergency stop order and a second consecutive emergency stop order, the control unit 14:

[0090] - places during the first phase, the first safety brake F1 in the active state and the second safety brake F2 in the inactive state,

[0091] - places during the second phase, the first safety brake F1 in the inactive state and the second safety brake F2 in the active state. The first safety brake and the second safety brake are identical, circumferentially offset from each other around the axis of rotation of the pulley, the first predetermined constant value of the first braking torque being equal to the second predetermined constant value of the second braking torque.

[0092] According to a non-limiting embodiment, the first safety brake F1 is configured so that the first predetermined constant value of the first braking torque is between 220 and 330 kNm and the second safety brake F2 is configured so that the second predetermined constant value of the second braking torque is between 220 and 330 kNm.

[0093] It is advantageous to provide that each of the first safety brake F1 and the second safety brake F2 comprises at least one braking member including a two-jaw caliper and two friction pads respectively secured to the two jaws. The friction pads vary, by relative movement between the jaws, between a first configuration where the friction pads do not exert friction forces on the pulley 10 and a second configuration in which the friction pads exert friction forces on the pulley 10.

[0094] In a first non-limiting embodiment, the first safety brake F1 comprises a single braking member as described above. The first braking torque, characterized by its first aforementioned value, then results from the friction forces applied to the pulley 10 by this single braking member when it is in its second configuration, and from the distance separating the center of rotation of the pulley 10 and the zone of application of the friction forces. Alternatively, the first safety brake F2 may comprise a first braking member and a second braking member, distinct from each other, both being as described above.The first braking torque then results on the one hand from the first friction forces applied to the pulley 10 by the first braking member when it is in its second configuration and from the distance separating the center of rotation of the pulley 10 and the zone of application of the first friction forces, and on the other hand from the second friction forces applied to the pulley 10 by the second braking member when it is in its second configuration and from the distance separating the center of rotation of the pulley and the zone of application of the second friction forces.

[0095] The second safety brake F2 may also comprise a single braking member as described above. The second braking torque, characterized by its second aforementioned value, then results from the friction forces applied to the pulley 10 by this single braking member when it is in its second configuration, and from the distance separating the center of rotation of the pulley 10 and the zone of application of the friction forces. Alternatively, the second safety brake F2 may comprise a first braking member and a second braking member, distinct from each other, both being as described above.The second braking torque then results on the one hand from the first friction forces applied to the pulley 10 by the first braking member when it is in its second configuration and from the distance separating the center of rotation of the pulley 10 and the zone of application of the first friction forces, and on the other hand from the second friction forces applied to the pulley 10 by the second braking member when it is in its second configuration and from the distance separating the center of rotation of the pulley 10 and the zone of application of the second friction forces.

[0096] According to a non-limiting embodiment, each braking member comprises an automatic return element such as a spring or a fixed load, permanently urging the friction pads towards the second configuration, and a hydraulic pressure supply opposing the action of the return element to urge the friction pads towards the first configuration only when the hydraulic pressure is applied.

[0097] Figure 4 represents the braking torque applied to the pulley (in kNm) on the ordinate as a function, on the abscissa, of the deceleration of the cable (in m / s2), for 4 different load states of the vehicles: curve P5 corresponds to a load state indicated as “0 / 100”, which means that 0 vehicles on the ascending track carry no load, while 100% of the vehicles on the descending track carry their maximum loads, curve P6 corresponds to a load state indicated as “100 / 100”, which means that 100% of the vehicles on the ascending track carry their maximum loads and 100% of the vehicles on the descending track carry their maximum loads, curve P7 corresponds to a load state indicated as “0 / 0”, which means that 0 vehicles on the ascending track carry no load and 0 vehicles on the descending track carry no load, curve P8 corresponds to a load state indicated as “100 / 0”, which means that 0 vehicles on the descending track are not carrying a load,while 100% of the vehicles in the ascending lane carry their maximum loads.,

[0098] The vertical lines passing through the values ​​X1 and X2 indicate the extreme values ​​of the deceleration range authorized by the administrative regulations, X1 being equal to 0.5 m / s 2 and X2 being equal to 1.25 m / s 2 .

[0099] The horizontal line passing through the value Y1 represents the first value taken by the first braking torque when the first safety brake is in the active state and the second safety brake is in the inactive state, or by the second value taken by the second braking torque when the first safety brake is in the inactive state and the second safety brake is in the active state (which corresponds to the implementation of the first operating mode described previously). Y1 is for example equal to 330 kNm. The horizontal line passing through the value Y2 represents the sum of the first value taken by the first braking torque and the second value taken by the second braking torque when the first safety brake is in the active state and the second safety brake is in the active state (which corresponds to the implementation of the second operating mode described previously). Y2 is for example equal to 660 kNm.

[0100] It can be seen that implementing the second operating mode, by applying a total torque equal to Y2 to the pulley by the two safety brakes, allows to remain within the range between X1 and X2 under the load conditions corresponding to curves P5, P6 and P7. On the other hand, as shown in point Q1, implementing the second operating mode under the load conditions according to curve P8 would result in a deceleration value that is significantly too high, beyond X2. This is why in this case the control unit would decide to place the cable transport installation in the first operating mode, with only one of the two safety brakes in the active state.

[0101] It can also be seen in Figure 4 that the implementation of the first operating mode, by applying to the pulley a braking torque equal to Y1 by the first safety brake or by the second safety brake, makes it possible to remain within the range between X1 and X2 under the load conditions corresponding to curves P6, P7 and P8. On the other hand, as shown in point Q2, the implementation of the first operating mode under the load conditions according to curve P5 would result in a deceleration value that is clearly too low, below X1. This is the reason why in this case, the control unit would decide to place the cable transport installation in the second operating mode, with a transition of the first safety brake and the second safety brake to their active states.

Claims

CLAIMS 1. Cable transport installation comprising a hauling carrier cable arranged in a closed loop, at least one rotatably mounted pulley (10) applying a longitudinal force to the cable for its running movement, a plurality of vehicles attached to the cable, a motorization system (12) transmitting a mechanical torque (CM) to the pulley (10) for its rotation and the generation of said longitudinal force, the motorization system (12) comprising at least one electric motor, a first safety brake (F1) cooperating by friction with the pulley (10), varying between an inactive state in which the first safety brake (F1) allows free rotation of the pulley (10) and an active state in which the first safety brake (F1) mechanically brakes the pulley (10) by friction by transmitting to the pulley (10) a first braking torque having a first predetermined constant value,a second safety brake (F2) cooperating by friction with the pulley (10), varying between an inactive state in which the second safety brake (F2) allows free rotation of the pulley (10) and an active state in which the second safety brake (F2) mechanically brakes the pulley (10) by friction by transmitting to the pulley (10) a second braking torque having a second predetermined constant value, a control unit (14) configured to: o receive at least one emergency stop command (01), o receive an acquisition signal (SA) whose value is representative of the evolution over time of said mechanical torque (CM), o transmit control signals (SP) to the motorization system (12), o transmit first control signals (SC1) to the first safety brake (F1) in order to place the first safety brake (F1) selectively in its active state or in its inactive state,o transmitting second control signals (SC2) to the second safety brake (F2) in order to place the second safety brake (F2) selectively in its active state or in its inactive state, the first control signals (SC1) and the second control signals (SC2) emitted by the control unit (14) after the emergency stop order (01) has been received by the control unit (14) being a function of the value taken by the acquisition signal (SA) at the time of receipt of the emergency stop order (01)., 2. Cable transport installation according to claim 1, in which the control signals (SP) transmitted to the motorization system (12) and emitted by the control unit (14) after receipt of the emergency stop order (01) are a function of the value taken by the acquisition signal (SA) at the time of receipt of the emergency stop order (01).

3. Cable transport installation according to one of claims 1 or 2, in which the value of the acquisition signal (SA) is representative, at each instant, of the electrical intensity consumed by the electric motor of the motorization system (12).

4. Cable transport installation according to one of claims 1 to 3, in which the control unit (14) is capable of placing the cable transport installation, after receiving the emergency stop order (01), among: a first operating mode in which a safety brake chosen from the first safety brake (F1) and the second safety brake (F2) occupies its active state and the other safety brake from the first safety brake (F1) and the second safety brake (F2) occupies its inactive state, only one from the first braking torque and the second braking torque being transmitted to the pulley (10), the control unit (14) automatically placing the cable transport installation in the first operating mode when the following first condition (C1) is verified: the value taken by the acquisition signal (SA) at the time of receiving the emergency stop order (01),is between a low threshold and a high threshold, predetermined and recorded in a memory of the control unit (14), a second operating mode in which the first safety brake (F1) is in its active state and simultaneously the second safety brake (F2) occupies its active state, the first braking torque and the second braking torque being jointly transmitted to the pulley (10), the control unit (14) automatically placing the cable transport installation in the second operating mode when the following second condition (02) is verified: the value taken by the acquisition signal (SA) at the time of receipt of the emergency stop order (01) is strictly greater than the predetermined high threshold., 5. Cable transport installation according to claim 4, in which the control unit (14) is configured so as to automatically place the cable transport installation, after receiving the emergency stop order (01), in a third operating mode in which the first safety brake (F1) is in its inactive state and simultaneously the second safety brake (F2) occupies its inactive state, when the third condition (03) is verified: the value taken by the acquisition signal (SA) at the time of receiving the emergency stop order (01) is strictly lower than the predetermined low threshold.

6. Cable transport installation according to claim 5, wherein in the third operating mode, the control unit (14) transmits, after receiving the emergency stop order (01), control signals (SP) to the motorization system (12) modulated so that the electric motor transmits to the pulley (10) a resistive mechanical torque (CM) regulated over time so that the electric motor carries out a control of the running speed of the cable according to a predetermined deceleration setpoint curve recorded in a memory of the control unit (14), the deceleration setpoint curve being activated by said emergency stop order (01).

7. Cable transport installation according to one of claims 4 to 6, the first predetermined constant value of the first braking torque for which the first safety brake (F1) is dimensioned, the second predetermined constant value of the second braking torque for which the second safety brake (F2) is dimensioned, the predetermined high threshold and the predetermined low threshold are configured so that the deceleration of the cable is, after receipt of the emergency stop order (01), between 0.5 m / s 2 and 1.25 m / s 2 .

8. Cable transport installation according to one of claims 1 to 7, comprising at least one first human-machine interface (16) and at least one automatic failure detection device (18) and in which the emergency stop order (01) is issued by an element chosen from the human-machine interface (16) and the automatic failure detection device (18).

9. Cable transport installation according to one of claims 1 to 8, comprising a second human-machine interface (20) allowing a user to generate a braking order (02) if a slowing down or a stopping of the cable is desired by the user, and in which the control unit (14) is able to receive said braking order (02), which is distinct from the emergency stop order (01), and in which after receiving said braking order (02), the control unit (14) transmits to the motorization system (12) control signals (SP) configured so that the electric motor transmits to the pulley (10) a resistant mechanical torque (CM) adapted to carry out said slowing down or stopping of the cable, the first safety brake (F1) and the second safety brake (F2) both being in the inactive state.

10. Cable transport installation according to one of claims 1 to 9, wherein the control unit (14) is configured so that during a first phase and a second successive phase in which the cable transport installation is placed in the first operating mode after receiving respectively a first emergency stop order (01) and a second emergency stop order (01) consecutively, the control unit: places during the first phase, the first safety brake (F1) in the active state and the second safety brake (F2) in the inactive state, place during the second phase, the first safety brake (F 1 ) in the inactive state and the second safety brake (F2) in the active state.

11. Cable transport installation according to one of claims 1 to 10, in which the first safety brake (F1) and the second safety brake (F2) are identical, circumferentially offset from each other around the axis of rotation of the pulley (10), the first predetermined constant value of the first braking torque being equal to the second predetermined constant value of the second braking torque.

12. Cable transport installation according to one of claims 1 to 11, in which each of the first safety brake (F1) and the second safety brake (F2) comprises at least one braking member including a two-jaw caliper and two friction pads respectively secured to the two jaws, the friction pads varying, by relative movement between the jaws, between a first configuration where the friction pads do not exert friction forces on the pulley and a second configuration in which the friction pads exert friction forces on the pulley.

13. A cable transport installation according to claim 12, wherein each braking member comprises an automatic return element such as a spring or a fixed load, permanently urging the friction pads towards the second configuration, and a supply of hydraulic pressure opposing the action of the return element to urge the friction pads towards the first configuration only when the hydraulic pressure is applied.

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