Cable transport system with two safety brakes with constant force and selectively or simultaneously actuable

Abstract

A cable transport system is described in which the pulley (10) is mechanically braked by friction, either selectively or simultaneously, by a first safety brake (F1) capable of applying a first constant predetermined braking torque and by a second safety brake (F2) capable of applying a second constant predetermined braking torque. A control unit (14) operates these two safety brakes (F1, F2), after receiving an emergency stop command (O1), based on a parameter representing a mechanical torque (CM) transmitted to the pulley (10) by a drive system (12). Figure 3

Description

Title of the invention: Cable transport system with two safety brakes with constant force and actuable selectively or simultaneously Technical field of the invention

[0001] The present invention relates to a cable transport installation comprising:

[0002] - a hauling carrier cable arranged in a closed loop,

[0003] - at least one rotating pulley applying a longitudinal force on the cable for its scrolling motion,

[0004] - a plurality of vehicles attached to the cable,

[0005] - a motorization system transmitting a mechanical torque to the pulley for its rotation and generation of said longitudinal force, the drive system comprising at least one electric motor,

[0006] - a first safety brake cooperating by friction with the pulley, varying between a 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,

[0007] - a second safety brake cooperating by friction with the pulley, varying between a 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,

[0008] - a control unit operating the motorization system and the safety brakes and capable of receiving emergency stop orders.

[0009] The vehicles are seats and / or cabins, intended for the transport of persons or equipment between two points served by the cable transport installation. Prior art

[0010] Fig. 1 represents in a simplified manner the essential elements of a station of an example of a known cable transport installation.

[0011] Thus, cable transport systems generally include a pulley 1 that transfers mechanical torque to the cable to ensure its movement. This mechanical torque can be resistive or driving, depending on the gradient of the line and 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 drive system that includes, in series, a gearbox 2, generally with a right-angle drive, and an electric motor 3.

[0012] 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 reference number 4, - a safety braking system.

[0013] The electric braking system is ensured by appropriate control of the electric motor, particularly when normal deceleration or a normal stop with reduced deceleration is required during operation. The electric braking system uses the service braking system 4 when the cable is stopped.

[0014] 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.

[0015] The safety braking system includes two safety brakes 5, 6, each having a caliper mechanically applying a braking torque by friction directly to the pulley.

[0016] In normal operation, the service braking system 4 is designed to ensure cable deceleration, even under the most severe gradient or load conditions, within the range of values ​​imposed by administrative regulations, namely between 0.5 m / s² and 1.25 m / s². 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 fault detection system. The deceleration is then significantly greater than the deceleration achieved, under normal conditions, by the electric braking system.

[0017] The safety braking system is used in the event of a failure of the service braking system 4. It is an additional safety feature in case of a serious problem with the cable transport installation. The safety braking system is designed to ensure that the cable decelerates, even under the most severe conditions of gradient or load, within the range of values ​​imposed by administrative regulations, namely between 0.5 m / s² and 1.25 m / s².

[0018] The braking force required to achieve such decelerations depends on the load on the line and its distribution between the ascending and descending tracks. If the vehicles are loaded along the ascending track, the braking force required is less than when the vehicles are loaded along the descending track. In long and / or very steep cable transport installations, it is sometimes not possible to find settings for the service braking system and the safety braking system that allow the deceleration requirements to be met, which are between 0.5 m / s² and 1.25 m / s² for all load conditions.

[0019] Figure 2 illustrates this prior art problem. It represents the braking torque applied to the pulley (in kNm) on the ordinate as a function, on the abscissa, of the cable deceleration (in m / s²), for 4 different vehicle load states: - The PI curve corresponds to a load state indicated as "0 / 100", meaning that 0 vehicles in the uphill lane are carrying no load, while 100% of the vehicles in the downhill lane are carrying their maximum loads. - Curve P2 corresponds to a load state indicated as "100 / 100", meaning that 100% of vehicles in the uphill lane are carrying their maximum loads and 100% of vehicles in the downhill lane are carrying their maximum loads. - Curve P3 corresponds to a load state indicated as "0 / 0", which means that 0 vehicles in the uphill lane are carrying a load and 0 vehicles in the downhill lane are carrying a load. - Curve P4 corresponds to a load state indicated as "100 / 0", which means that 0 vehicles in the descending lane are carrying loads, while 100% of the vehicles in the ascending lane are carrying their maximum loads.

[0020] The vertical lines passing through the values ​​XI and X2 indicate the extreme values ​​of the deceleration range authorized by the administrative regulations, XI being equal to 0.5 m / s2 and X2 being equal to 1.25 m / s2.

[0021] Fig. 2 illustrates that it is not possible to find a value in ordinates (i.e. a value of braking torque applied to the pulley (in kNm) by the service or safety braking system) for which all the curves PI, P2, P3 and P4 are jointly between XI and X2.

[0022] In this case, it is typically necessary to install additional inertias (rotating masses) to reduce the influence of the load on board the vehicles.

[0023] This type of installation is not entirely satisfactory. Firstly, the separate presence of a service braking system and a safety braking system makes the solution complex and expensive.

[0024] On the other hand, the use of a service braking system acting at the level of the electric motor implies high operating temperatures, high rotational speeds, and high wear rates of the friction pads; thus the service braking system is not totally reliable and implies a high level of maintenance.

[0025] Moreover, the sometimes necessary recourse to additional inertias is not satisfactory because it represents losses in efficiency, the presence of unnecessary parts and implies adjustments on a case-by-case basis.

[0026] Since the safety braking system is used in the event of a failure of the service braking system 4, the switch from one to the other may take some time, in addition to the extra time resulting from the failure itself. of the service braking system, and this may involve an emergency braking that is too long and does not meet the aforementioned deceleration requirements set by administrative regulations.

[0027] Finally, the total braking torque that could be applied if the service braking system and the safety braking system were to be unintentionally activated simultaneously would result in a significantly excessive level of deceleration, typically on the order of 2.5 m / s², which would be dangerous for the occupants of the vehicles. This type of risk must be managed by additional means, which increases the complexity, cost, and unreliability of known transport systems.

[0028] Document FR2904594 describes an alternative solution in which the safety braking system comprises two independent brakes, each capable of braking the transport installation to a deceleration level within the range defined by administrative regulations. A speed sensor provides an acquisition signal representing the cable's travel speed. Each brake is complex and expensive, as each includes pressure regulation to generate pressure forces and thus adjustable braking torques that can be varied as desired over time. The control unit transmits initial control signals to the first brake, which are modulated to control the cable speed according to a predetermined deceleration setpoint curve activated by the braking command.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 command, the instantaneous value of the second setpoint curve being greater, at each instant, than the value of the first setpoint curve.

[0029] However, once again, this type of transport system is complex and expensive due to the nature of the emergency brakes, which require modulation, adjustment, and control mechanisms. This also results in a lack of reliability due to the complexity and number of mechanical, electrical, and software components involved. Object of the invention

[0030] The present invention aims to provide a cable transport installation that is simple, economical, robust and reliable.

[0031] This objective can be achieved through the provision of a cable transport installation comprising: - a traction cable arranged in a closed loop, - at least one rotating pulley applying a longitudinal force to the cable for its unspooling movement, - a plurality of vehicles attached to the cable, - a drive system transmitting mechanical torque to the pulley for its rotation and the generation of said longitudinal force, the drive 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 for: • receive at least one emergency stop order, • receive an acquisition signal whose value is representative of the evolution over time of said mechanical torque, • transmit control signals to the drive system, • transmit initial control signals to the first safety brake in order to selectively place the first safety brake in its active or inactive state, • transmit second control signals to the second safety brake in order to selectively place the second safety brake in its active or inactive state,

[0032] 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 the receipt of the emergency stop order.

[0033] Such a cable transport system is simple, economical, robust, and reliable. Indeed, with this design, it is no longer necessary to use a service braking system as was the case in the prior art presented previously. It also eliminates the need for any additional inertia, even for long and / or steep installations, since it is sufficient to dimension the first The safety brake and the second safety brake are appropriately engaged. Furthermore, any risk of deceleration exceeding 1.25 m / s² is eliminated. Moreover, the very nature of the two safety brakes makes them economical, reliable, and robust.

[0034] Some preferred but not limiting aspects are the following.

[0035] The control signals transmitted to the drive system and issued by the control unit, after receiving the emergency stop command, depend on the value of the acquisition signal at the moment the emergency stop command is received. This allows for 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 deceleration and stopping of the installation are carried out solely by the electric motor, without the safety brakes being activated. Conversely, above this threshold, the control signals will be modulated so that the electric motor does not participate in transmitting braking torque to the pulley, leaving this operation exclusively to at least one of the two safety brakes, or even both.

[0036] The value of the acquisition signal is representative, at each instant, of the electrical current consumed by the electric motor of the drive system. These features allow for simple, reliable, and economical management by the control unit, eliminating the need for another type of sensor.

[0037] The control unit is capable of placing the cable transport installation, after receiving the emergency stop order, into one of the following positions:

[0038] - a first mode of operation in which a safety brake chosen from The first safety brake and the second safety brake are in their active state, and the other safety brake, one of the first and the other, is in its inactive state. Only one of the first and second braking torques is transmitted to the pulley. The control unit automatically places the cable transport system in the first operating mode when the following condition is met: the value of the acquisition signal at the time of receiving the emergency stop command is between a predetermined low and high threshold, stored in the control unit's memory.

[0039] - a second mode of operation 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 system in the second operating mode when the following second condition is met: the value taken by the acquisition signal at the time the receipt of the emergency stop order is strictly greater than the predetermined upper threshold.

[0040] These provisions ensure that the cable transport system is reliable, economical, and robust. Safety braking is achieved by simply switching the two safety brakes between their active and inactive states, adapting the braking torque applied to the pulley to the precise requirements in real time, according to the load conditions and the load distribution between the ascending and descending lines. This first operating mode also eliminates the risk of excessive resistive torque and prevents the risk of excessive deceleration, which could otherwise be dangerous. It also prevents unnecessary wear on the safety brakes by operating them selectively whenever possible, i.e., when the load to be stopped is not too heavy.

[0041] The control unit is configured so as to automatically place the cable transport installation, after receiving the emergency stop order, into a third operating mode in which the first safety brake is in its inactive state and simultaneously the second safety brake is in 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 less than the predetermined low threshold.

[0042] These provisions ensure that the cable transport system is reliable, economical, and robust. Safety braking is achieved by simply switching the two safety brakes between their active and inactive states, adapting the braking torque applied to the pulley to the precise requirements in real time, according to the load conditions and the load distribution between the uphill and downhill lines. The third operating mode avoids unnecessary use of the safety brakes when the electric motor alone, through appropriate control, is able to achieve the deceleration required for emergency braking, typically when the load is not very heavy or is primarily concentrated on the vehicles of the uphill line. This also prevents unnecessary wear on the safety brakes by not activating them when not required.

[0043] In the third operating mode, after receiving the emergency stop order, the control unit transmits modulated control signals to the motorization system so that the electric motor transmits to the pulley a time-regulated resisting mechanical torque so that the electric motor achieves a control of the cable's speed following a predetermined deceleration setpoint curve recorded in a memory of the control unit, the deceleration setpoint curve being activated by said emergency stop order. This offers the advantages already presented in connection with the presentation of the third operating mode, while ensuring that passenger comfort is very good by imposing a fairly low deceleration speed 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 upper threshold and the predetermined lower threshold are all four configured so that the deceleration of the cable, after receiving the emergency stop order, is between 0.5 m / s² and 1.25 m / s². It follows that the sole presence of the two safety brakes allows the cable transport installation to meet the requirements of the administrative regulations, very advantageously eliminating the need for a service braking system as was the case in the prior art presented in [Fig. 1], for reasons of reliability, cost, simplicity and robustness.

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

[0046] The cable transport system includes a second human-machine interface allowing a user to generate a braking command if the user desires the cable to slow down or stop. The control unit is capable of receiving this braking command, which is distinct from the emergency stop command. Upon receiving the braking command, the control unit transmits control signals to the drive system configured so that the electric motor transmits a suitable resisting mechanical torque to the pulley to achieve the slowing down or stopping of the cable, with both the first and second safety brakes inactive. These provisions ensure the rapid transmission of a braking stop command by a person, typically the personnel responsible for boarding or disembarking the vehicles.These provisions also ensure that the cable transport installation is reliable, economical, and robust. Normal braking, unlike emergency braking, is achieved by simply switching the two safety brakes to their inactive state and by simply controlling the electric motor to adapt the braking torque applied to the pulley to the precise need in real time and according to the conditions. load and load distribution between the uphill and downhill lines. Unnecessary use of safety brakes is avoided when the electric motor, through appropriate control, is capable of achieving the deceleration required for normal braking. This also prevents unnecessary wear on the safety brakes by not activating them when not required.

[0047] The control unit is configured so that during a first 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] - place during the first phase, the first safety brake in the active state and the second safety brake in the inactive state,

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

[0050] These provisions make it possible to guarantee an alternation between the safety brakes used during successive emergency braking, in order to obtain homogeneous wear of the two safety brakes over time, and reducing the need for control 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 a simplification of construction and management of parts, while also allowing for a reduction in 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 able to brake in an emergency 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 element including a two-jaw caliper and two friction pads respectively fixed to the two jaws, the friction pads varying, by relative displacement between the jaws, between a first configuration in which the friction pads do not exert frictional forces on the pulley and a second configuration in which the friction pads exert frictional forces on the pulley. These arrangements ensure that the safety brakes are economical, reliable, and simple in terms of maintenance.

[0056] Each braking device includes an automatic return element, such as a spring or a fixed load, which continuously returns the friction pads to the second position, and a hydraulic pressure supply that counteracts the action of the return element, returning the friction pads to the first position only when hydraulic pressure is applied. These arrangements ensure that the safety brakes are economical, reliable, and easy to maintain. They are also safe because, in the event of a failure of the hydraulic pressure supply, the braking torques are automatically applied to stop the cable travel and the operation of the cable transport system. Brief description of the drawings

[0057] Other aspects, objectives, advantages and features of the invention will become clearer upon reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0058] [Fig-1] Fig. 1, already described, represents in a simplified manner the elements essentials of a station in an example of a known cable transport installation.

[0059] [Fig.2] Fig.2, already described with reference to the prior 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.

[0060] [Fig.3] Fig.3 represents in a simplified manner the essential elements of a station of an example of a cable transport installation according to the invention.

[0061] [Fig.4] Fig.4 represents, for the example of Fig.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.

[0062] [Fig. 5] The figure represents by block diagram the essential elements already visible on the [Fig.3] and their interactions.

[0063] [Fig.6] Fig.6 represents a flowchart of operating steps of the cable transport installation of figures 3 and 5. Detailed description

[0064] In Figures 3 to 6 and in the rest of the description, the same reference numerals represent identical or similar elements. Furthermore, the various elements are not drawn to scale in order to prioritize the clarity of the figures. By Moreover, the different modes of embodiment and variants are not mutually exclusive and can be combined with each other.

[0065] With reference to Figures 3 and 5, a cable transport installation comprises a haul rope arranged in a closed loop, at least one pulley 10 mounted for rotation applying a longitudinal force on the cable for its movement of running and a plurality of vehicles attached to the cable.

[0066] The vehicles are seats and / or cabins, intended for the transport of persons or equipment between two points served by the cable transport installation.

[0067] The length and slope of the cable depend on the terrain on which the transport installation is built and the distance between the downstream station and the upstream station.

[0068] The cable transport system includes a drive system 12 transmitting a mechanical torque CM to the pulley 10 to rotate it and generate the longitudinal force. The drive system includes at least one electric motor. The transmission between the drive system 12 and the pulley 10 can be direct, with the rotor of the electric motor directly coupled to the pulley 10, or indirect, through the interposition of a gearbox.

[0069] The cable transport installation includes a first safety brake Fl cooperating by friction with the pulley 10. The first safety brake Fl varies between an inactive state in which the first safety brake Fl allows free rotation of the pulley 10 and an active state in which the first safety brake Fl mechanically brakes the pulley 10 by friction by transmitting to the pulley 10 a first braking torque having a first predetermined constant value.

[0070] The cable transport installation also includes 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.

[0071] The first safety brake Fl 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 between 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 between the point of application of the second force and the center of rotation of the pulley 10.

[0072] The cable transport installation includes a control unit 14 configured to receive at least one emergency stop command 01, to receive a signal acquisition 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 SCI to the first safety brake Fl in order to place the first safety brake Fl 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.

[0073] The first SCI control signals and the second SC2 control signals emitted by the control unit 14 after the receipt of the emergency stop order 01 by the control unit 14 depend directly on the value taken by the acquisition signal SA at the moment of the receipt of the emergency stop order 01 by the control unit 14.

[0074] The SP pilot signals transmitted to the drive system 12 and emitted by the control unit 14, after receiving the emergency stop order 01, are a function of the value taken by the acquisition signal SA at the time of receiving the emergency stop order 01 by the control unit 14.

[0075] 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 the load carried on board the vehicles and / or the speed of the cable.

[0076] According to one embodiment, starting from an initial situation SI in which the transport installation is in a stable normal regime where the cable is moving at a normal speed, the control unit 14 is capable of placing the cable transport installation, after receiving the emergency stop command 01, by a specific modulation of the first control signals SCI and the second control signals SC2, among:

[0077] - a first mode of operation in which a safety brake chosen from The first safety brake Fl and the second safety brake F2 are in their active state, and the other safety brake, either the first safety brake Fl or the second safety brake F2, is in its inactive state. Only one of the first and second braking torques is transmitted to the pulley 10. The control unit 14 automatically places the cable transport system in the first operating mode when the following first condition Cl is met: the value taken by the acquisition signal SA at the moment of receiving the emergency stop command. 01, is between a low threshold and a high threshold, predetermined and recorded in a memory of the control unit 14,

[0078] - a second mode of operation in which the first safety brake Fl is in its active state and simultaneously the second safety brake F2 is in 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 time of receiving the emergency stop order 01 is strictly greater than the predetermined high threshold.

[0079] Step E5 corresponds to the reception of the emergency stop command 01 by the control unit 14, which, in step E6, determines the value of the acquisition signal SA to be representative of the mechanical torque transmitted to the pulley 10 at the moment the emergency stop command 01 was received. Then, in step E7, the control unit compares this value to the upper and lower thresholds. If the first condition C1 is met, then the first operating mode is adopted in step E8. If the second condition C2 is met, then the second operating mode is adopted in step E9.

[0080] The control unit 14 is configured to automatically place the cable transport system, after receiving the emergency stop command 01, into a third operating mode in which the first safety brake Fl is in its inactive state and simultaneously the second safety brake F2 is in its inactive state, when the third condition C3 is met: the value of the acquisition signal SA at the moment of receiving the emergency stop command 01 is strictly less than the predetermined lower threshold. If, at step E7, the control unit 14 determines that the value of the acquisition signal SA is less than the lower threshold, then the third condition C3 is met and the control unit 14 places the transport system into the third operating mode at step E10.

[0081] In the third mode of operation, 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 time-regulated resistive mechanical torque CM so that the electric motor achieves a control of the cable's speed following 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.

[0082] Alternatively, depending on the load, the slope and the expected deceleration speed, it is possible to foresee that in the third operating mode, after receiving the emergency stop order 01, such pilot 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 resisting mechanical torque applied by the electric motor for this purpose.

[0083] According to a non-limiting embodiment, the first predetermined constant value of the first braking torque for which the first safety brake Fl is sized, the second predetermined constant value of the second braking torque F2 for which the second safety brake is sized, the predetermined upper threshold and the predetermined lower threshold are all four configured so that the deceleration of the cable is, after receiving the emergency stop order 01, between 0.5 m / s2 and 1.25 m / s2.

[0084] With reference to [Fig.5], the cable transport installation includes at least one first human-machine interface 16 and at least one automatic fault detection device 18, the emergency stop order 01 being issued by an element chosen from the human-machine interface 16 and the automatic fault detection device 18. These arrangements ensure rapid transmission of an emergency stop order 01 by a person, typically the personnel responsible for boarding or disembarking the vehicles, or by a safety sensor such as, for example, a sensor detecting a derailment or any other failure.

[0085] The cable transport installation includes a second human-machine interface 20 allowing a user to generate a braking command 02 if a slowing down or stopping of the cable is desired by the user, the control unit 14 being able to receive this braking command 02, which is distinct from the emergency stop command 01; after receiving the braking command 02, the control unit 14 transmits to the drive system 12 pilot signals SP configured so that the electric motor transmits to the pulley 10 a suitable mechanical resisting torque to achieve this slowing down or stopping of the cable, the first safety brake Fl and the second safety brake F2 both being in the inactive state thanks to a circumstantial modulation of the first control signals SCI and the second control signals SC2.

[0086] Starting from the initial situation SI, step El corresponds to the reception of the braking command 02 by the control unit 14, which transmits to the drive system 12 control signals SP configured so that, in a step E2, the electric motor transmits to the pulley 10 a resisting mechanical torque ensuring the deceleration corresponding to what is expected following the issuance of the braking order 02.

[0087] The control unit 14 is configured so that during a first 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:

[0088] - place during the first phase, the first safety brake Fl in the active state and the second safety brake F2 in the inactive state,

[0089] - during the second phase, the first safety brake Fl is in the inactive state and the second safety brake F2 in the active state.

[0090] 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.

[0091] According to a non-limiting embodiment, the first safety brake Fl 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.

[0092] It is advantageous to provide that each of the first safety brake Fl and the second safety brake F2 comprises at least one braking element including a two-jaw caliper and two friction pads respectively fixed to the two jaws. The friction pads vary, by relative displacement between the jaws, between a first configuration in which the friction pads do not exert frictional forces on the pulley 10 and a second configuration in which the friction pads do exert frictional forces on the pulley 10.

[0093] In a first, non-limiting embodiment, the first safety brake Fl comprises a single braking element as described above. The first braking torque, characterized by its first value mentioned above, is then derived from the frictional forces applied to the pulley 10 by this single braking element when it is in its second configuration, and from the distance separating the center of rotation of the pulley 10 and the area of ​​application of the frictional forces. Alternatively, the first safety brake F2 may comprise a first braking element and a second braking element, distinct from each other, both being as described above. The first braking torque is then derived, on the one hand, from the first frictional forces applied to the pulley 10 by the first braking element when it is in its second configuration and from the distance separating the center of rotation of pulley 10 and the area of ​​application of the first friction forces, and on the other hand of the second friction forces applied to pulley 10 by the second braking element when it is in its second configuration and the distance separating the center of rotation of the pulley and the area of ​​application of the second friction forces.

[0094] The second safety brake F2 may also comprise a single braking element as described above. The second braking torque, characterized by its second value mentioned above, is then derived from the frictional forces applied to the pulley 10 by this single braking element when it is in its second configuration, and from the distance between the center of rotation of the pulley 10 and the area of ​​application of the frictional forces. Alternatively, the second safety brake F2 may comprise a first braking element and a second braking element, distinct from each other, both being as described above.The second braking torque then results from, on the one hand, the first frictional forces applied to the pulley 10 by the first braking element when it is in its second configuration and the distance separating the center of rotation of the pulley 10 and the area of ​​application of the first frictional forces, and on the other hand, the second frictional forces applied to the pulley 10 by the second braking element when it is in its second configuration and the distance separating the center of rotation of the pulley 10 and the area of ​​application of the second frictional forces.

[0095] According to a non-limiting embodiment, each braking element includes an automatic return element such as a spring or a fixed load, continuously 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 hydraulic pressure is applied.

[0096] 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 vehicle load states: - Curve P5 corresponds to a load state indicated as "0 / 100", meaning that 0 vehicles in the uphill lane are carrying no load, while 100% of the vehicles in the downhill lane are carrying their maximum loads. - Curve P6 corresponds to a load state indicated as "100 / 100", meaning that 100% of the vehicles in the uphill lane and 100% of the vehicles in the downhill lane are carrying their maximum loads. - Curve P7 corresponds to a load state indicated as "0 / 0", which means that 0 vehicles in the uphill lane are carrying a load and 0 vehicles in the downhill lane are carrying a load. - Curve P8 corresponds to a load state indicated as "100 / 0", which means that 0 vehicles in the descending lane are carrying loads, while 100% of the vehicles in the ascending lane are carrying their maximum loads.

[0097] The vertical lines passing through the values ​​XI and X2 indicate the extreme values ​​of the deceleration range authorized by the administrative regulations, XI being equal to 0.5 m / s2 and X2 being equal to 1.25 m / s2.

[0098] The horizontal line passing through the value Y1 represents the first value of 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 the second value of 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 above). Y1 is, for example, equal to 330 kNm. The horizontal line passing through the value Y2 represents the sum of the first value of the first braking torque and the second value of 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 above). Y2 is, for example, equal to 660 kNm.

[0099] It can be seen that implementing the second operating mode, by applying a total torque of Y2 to the pulley via both safety brakes, allows the system to remain within the range between XI and X2 under the load conditions corresponding to curves P5, P6, and P7. However, as shown by 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, exceeding X2. Therefore, in this case, the control unit would decide to place the cable transport system in the first operating mode, with only one of the two safety brakes active.

[0100] It can also be seen in [Fig. 4] that implementing the first operating mode, by applying a braking torque of Y1 to the pulley using either the first or second safety brake, allows the system to remain within the range between XI and X2 under the load conditions corresponding to curves P6, P7, and P8. However, as shown in point Q2, implementing the first operating mode under the load conditions according to curve P5 would result in a deceleration value that is significantly too low, below XL. This is why, in this case, the control unit would decide to place the cable transport installation in the second operating mode, with the first safety brake and the second safety brake passing into their active states.

Claims

1. Demands Cable transport installation including - a traction cable arranged in a closed loop, - at least one pulley (10) mounted for rotation applying a longitudinal force to the cable for its movement, - a plurality of vehicles attached to the cable, - a drive system (12) transmitting a mechanical torque (CM) to the pulley (10) for its rotation and the generation of said longitudinal force, the drive system (12) comprising at least one electric motor, - a first safety brake (Fl) cooperating by friction with the pulley (10), varying between an inactive state in which the first safety brake (Fl) allows free rotation of the pulley (10) and an active state in which the first safety brake (Fl) 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 for: • receive at least one emergency stop order (01), • receive an acquisition signal (SA) whose value is representative of the evolution over time of said mechanical torque (CM), • transmit control signals (SP) to the drive system (12), • transmit first control signals (SCI) to the first safety brake (Fl) in order to place the first safety brake (Fl) selectively in its active state or in its inactive state, • 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, the first control signals (SCI) and the second control signals (SC2) emitted by the control unit (14) after the receipt of the emergency stop order (01) by the control unit (14) being a function of the value taken by the acquisition signal (SA) at the time of the receipt of the emergency stop order (01).

2. Cable transport installation according to claim 1, wherein the control signals (SP) transmitted to the drive system (12) and emitted by the control unit (14) after receiving the emergency stop order (01) are a function of the value taken by the acquisition signal (SA) at the time of receiving the emergency stop order (01).

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

4. A cable transport system according to any one of claims 1 to 3, wherein the control unit (14) is capable of placing the cable transport system, after receiving the emergency stop command (01), into one of the following operating modes: - a first operating mode in which one safety brake selected from the first safety brake (F1) and the second safety brake (F2) is in its active state and the other safety brake selected from the first safety brake (F1) and the second safety brake (F2) is in its inactive state, only one of the first and second braking torques being transmitted to the pulley (10), the control unit (14) automatically placing

5.

6. the cable transport installation in the first operating mode when the following first condition (Cl) 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), - a second operating mode in which the first safety brake (F1) is in its active state and simultaneously the second safety brake (F2) is in 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 time of receiving the emergency stop order (01) is strictly greater than the predetermined upper threshold. Cable transport installation according to claim 4, wherein the control unit (14) is configured so as to automatically place the cable transport installation, after receiving the emergency stop order (01), into a third operating mode in which the first safety brake (F1) is in its inactive state and simultaneously the second safety brake (F2) is in its inactive state, when the third condition (C3) is verified: the value taken by the acquisition signal (SA) at the time of receiving the emergency stop order (01) is strictly less than the predetermined low threshold. A cable transport installation according to claim 5, wherein in the third operating mode, the control unit (14) transmits, after receiving the emergency stop command (01), modulated control signals (SP) to the drive system (12) such that the electric motor transmits to the pulley (10) a time-regulated resistive mechanical torque (CM) so that the electric motor achieves a servo control of the cable's travel speed according to a predetermined deceleration setpoint curve stored in a memory of the control unit (14), the deceleration setpoint curve being activated by said emergency stop command (01).

7. Cable transport installation according to any one of claims 4 to 6, the first predetermined constant value of the first braking torque for which the first safety brake (F1) is sized, the second predetermined constant value of the second braking torque for which the second safety brake (F2) is sized, the predetermined upper threshold and lower threshold are configured so that the deceleration of the cable is, after receipt of the emergency stop order (01), between 0.5 m / s2 and 1.25 m / s2.

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

9. A cable transport installation according to any one of claims 1 to 8, comprising a second human-machine interface (20) enabling a user to generate a braking command (02) if a slowing down or stopping of the cable is desired by the user, and wherein the control unit (14) is capable of receiving said braking command (02), which is distinct from the emergency stop command (01), and wherein after receiving said braking command (02), the control unit (14) transmits to the drive system (12) pilot signals (SP) configured so that the electric motor transmits to the pulley (10) a resisting mechanical torque (CM) suitable for effecting 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. A cable transport installation according to any one of claims 1 to 9, wherein the control unit (14) is configured such that during a first 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 command (01) and a second consecutive emergency stop command (01), the control unit: - during the first phase, place the first safety brake (Fl) in the active state and the second safety brake (F2) in the inactive state, - during the second phase, place the first safety brake (Fl) in the inactive state and the second safety brake (F2) in the active state.

11. Cable transport installation according to any one of claims 1 to 10, wherein 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 any one of claims 1 to 11, wherein each of the first safety brake (F1) and the second safety brake (F2) comprises at least one braking element including a two-jaw caliper and two friction pads respectively attached to the two jaws, the friction pads varying, by relative displacement between the jaws, between a first configuration in which the friction pads do not exert frictional forces on the pulley and a second configuration in which the friction pads exert frictional forces on the pulley.

13. Cable transport installation according to claim 12, wherein each braking element includes an automatic return element such as a spring or a fixed load, continuously 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 hydraulic pressure is applied.

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