Cable transport installation, method of detecting an event on a cable and manufacturing method

Abstract

A cable transport installation (1) comprising a cable (2) supported by several pulleys (5) of several pillars (4). At least one pillar (4) is provided with at least one optical fuse (6) defining a first and a second state in which an optical signal can or cannot flow. Detection means (7, 8) are configured to detect a derailment of the cable (2) from one of the pulleys (5). The detection means make the signal flow through the optical fuses (6) to monitor their state. The optical fuses (6) are configured to change state between the first state and the second state when at least one of the optical fuses (6) comes into contact with the cable (2) or one of its supports. The detection means emit an alert in response to detecting a change of state of one of the optical fuses (6). Each optical fuse (6) comprises an optical fiber.

Description

Technical Field

[0001] The present invention relates to a cable transport device, a method for detecting events on a cable, and a method for manufacturing such a device. Background Technology

[0002] Cable transport equipment typically consists of one or more cables that support and move the carriages. The cables are held in place by multiple pulleys arranged along the cableway.

[0003] The cable may abnormally disengage from the groove of the pulley, potentially causing it to fall. It is particularly important to be able to detect the movement of the cable as it emerges from the groove and the location of the post associated with the event. As described in document FR2548612, connecting one or more electrical safety lines to a cableway, and the interruption of these lines, especially in the event of cable derailment, will lead to equipment shutdown. In FR2548612, the safety line includes at least one conductive breakable band located near the cable guide pulley and designed to break upon cable drop. Therefore, a cable drop will cause the safety line to break and the equipment to shut down.

[0004] However, the electrical performance of electrical circuits varies considerably with temperature, and more generally with weather conditions, making the electrical performance of the detection system susceptible to change. Uneven changes in the electrical performance of electrical circuits due to aging have also been observed. The detection system may also experience transient faults, at least in part, related to the connection of the detectors on the power lines that connect the detectors to the central control circuit. This renders the solution unsatisfactory. To reduce the risk of harmful tripping, it is known to install a second circuit connected in parallel with the first circuit, with the second destructible strip installed just next to the first strip. Again, this solution is unsatisfactory because it increases the cost and installation complexity associated with cable event detection.

[0005] The control circuit for installing different posts is known from document FR2946940. The circuit consists of more posts than are being tested. The circuit includes one or more fuse elements mounted on the posts to detect derailment. No electrical signal flows between two adjacent electrical lines, thus allowing determination of which post experienced derailment.

[0006] It is also evident that the conductors in the circuit do not age at the same rate because they are located at different altitudes and are affected by different weather conditions (wind and sun). This makes the solution proposed in document FR2946940 not entirely satisfactory. Summary of the Invention

[0007] One object of the present invention is to provide a cable transport device capable of rapidly detecting events on the cable, such as cable derailment, pulley loss, or pulley blockage, and making it easier to determine which post is associated with the event. To this end, the cable transport device includes:

[0008] Cable

[0009] A plurality of posts, each post having at least one pulley, are arranged such that a cable is supported by the at least one pulley of the plurality of posts. At least one of the plurality of posts is provided with at least one fuse, which defines a first state that allows a signal to pass and a second state that blocks the signal from passing.

[0010] A detection device is configured to detect at least one cable event, the detection device causing a signal to flow through at least one fuse of the plurality of posts to monitor the state of the at least one fuse, the at least one fuse being configured to change state between a first state and a second state when the fuse detects the at least one cable event, and the detection device being configured to issue an alarm in response to detecting a state change of the at least one fuse of the plurality of posts.

[0011] The notable feature of this cable transport device is that the at least one fuse is an optical fuse including an optical fiber, and the detection device includes a transmitter device configured to transmit optical signals and a receiver device configured to receive the optical signals, the transmitter device being connected to the receiver device via the at least one optical fuse.

[0012] The detection device preferably includes at least one optical fuse configured to change state when the at least one optical fuse is mechanically compressed by a cable.

[0013] According to one development of the invention, the at least one optical fuse is configured to cut the optical fiber when the at least one optical fuse is mechanically compressed by the cable.

[0014] In an advantageous manner, the at least one optical fuse is configured to cut the optical fiber by shearing when the at least one optical fuse is mechanically compressed by the cable.

[0015] According to another development, the at least one optical fuse includes a pin movably mounted to cut the fiber optic loop when the pin is mechanically pressed by the cable. The at least one optical fuse includes a body defining a cavity and a fiber optic loop, the fiber optic loop being mounted within the cavity around two connection points separated by the pin. The at least one optical fuse is configured to detect cable derailment via the pin.

[0016] Advantageously, the fiber optic loop passes through the pin along the first axis, and more preferably, the pin is configured to rotate about a rotation axis perpendicular to and at a distance from the first axis to cut the fiber optic loop.

[0017] In a preferred manner, the at least one cable event is selected from the following events: cable derailment from at least one of the pulleys, loss of at least one of the pulleys, or blockage of at least one of the pulleys.

[0018] In a preferred manner, each post includes a catcher designed to receive cable detached from the at least one pulley. The at least one optical fuse protrudes from the catcher to be struck by the cable and to detect cable derailment. Alternatively, the catcher has a movable portion connected to the optical fuse to apply mechanical stress to the optical fuse when the movable portion is struck by the cable.

[0019] In one particular embodiment, the mechanical pressure of the cable on the at least one optical fuse is achieved through direct contact between the at least one optical fuse and the cable, and through the cable cutting the at least one optical fuse.

[0020] In another preferred embodiment, the detection device includes at least one optical fuse arranged to detect a missing or blocked pulley, the at least one optical fuse being functionally connected to the pulley assembly of the plurality of posts to change state when the pulley assembly rotates beyond a threshold.

[0021] Advantageously, several of the plurality of optical fuses are arranged in series on the optical circuit and are designed such that optical signals can flow through the latter. Each and at least one of the plurality of optical fuses is initially in a first state. The detection device includes a determining device configured to determine the position of the optical fuse in a second state among the series-connected optical fuses when a cable event has been detected.

[0022] Preferably, the determining device is configured to calculate the transit time of the emitted optical signal reflected by the severed optical fiber in order to determine the position of the optical fuse in the second state.

[0023] In a particular embodiment, each of the optical fuses is connected to the optical circuit via a connector that introduces at least one interference, and the determining device is configured to calculate the amount of interference experienced by the optical signal in order to determine the location of the optical fuse in the second state.

[0024] Also advantageous is that each column includes:

[0025] The control box is powered and connected to the control circuitry via optical lines.

[0026] Multiple optical fuses are connected to a control box, which contains transmitter and receiver units.

[0027] Another objective of this invention is to provide an effective detection method for cable incidents.

[0028] This objective is intended to be achieved by a method for detecting cable events in cable transport equipment, the method comprising at least the following steps:

[0029] A cable transport device is provided, including a cable, a plurality of posts, each post having at least one pulley, the cable being supported by at least one pulley of the plurality of posts, at least one of the plurality of posts having at least one fuse defining a first state that allows a signal to pass and a second state that prevents a signal from passing, the at least one fuse being configured to change state between the first state and the second state when the at least one fuse detects an event on the cable.

[0030] Signals are transmitted regularly through the fuse;

[0031] The detection signal receiver device does not receive the signal and thereby infers a change in the state of the at least one fuse representing an event on the cable.

[0032] The remarkable feature of this method is that the at least one fuse is an optical fuse including an optical fiber, the signal is an optical signal designed to pass through the optical fuse, and the receiver device is an optical receiver device.

[0033] Preferably, each optical fuse belongs to an optical connector, which are connected in series along an optical fiber. Each optical connector introduces interference into the optical signal as it passes through. The method includes counting down the amount of interference received into the optical signal to determine the number of optical connectors that have passed through, and assessing the location of the optical fuses that have changed state.

[0034] In an advantageous manner, optical fuses are connected in series along an optical fiber. Each pair of consecutive optical fuses along the fiber is separated by a threshold distance, which corresponds to the minimum distance along the fiber between the two optical fuses that allows them to be distinguished by a measuring device for optical signals. The determination of the optical fuse in a changed state is performed by calculating the time taken to receive the signal reflected by the fuse in a changed state.

[0035] Another object of the present invention is to provide a method for manufacturing cable transport equipment that is easy to implement and more efficient than the configurations of the prior art.

[0036] This result is likely achieved through a method for manufacturing cable transport equipment, which includes the following steps:

[0037] - Provides a cable transport device comprising a cable and a plurality of posts, each post being provided with at least one pulley, the cable being configured to be supported by the at least one pulley of the plurality of posts, at least one of the plurality of posts being provided with at least one electric fuse defining a first state that allows an electrical signal to pass through and a second state that prevents an electrical signal from passing through, the at least one fuse being configured to change state between the first state and the second state when the at least one electric fuse is mechanically compressed by the cable, the at least one electric fuse being connected to a detection circuit via a conductive cable;

[0038] - Replace the electrical fuse with an optical fuse, the optical fuse defining a first state that allows optical signals to pass and a second state that blocks optical signals from passing, the at least one optical fuse being configured to change state between the first state and the second state when the at least one optical fuse detects an event on the cable;

[0039] - Connect the at least one optical fuse to the detection circuit via optical lines. Attached Figure Description

[0040] Other advantages and features will become more apparent from the following description of specific embodiments and implementations of the invention, given for non-limiting purposes only and illustrated in the accompanying drawings. In the drawings:

[0041] Figure 1 A first embodiment of the device is schematically shown, which has a specific optical line connecting each post equipped with at least one optical fuse;

[0042] Figure 2 A second embodiment of the device is schematically shown, which has an optical circuit connecting all the posts provided with at least one optical fuse;

[0043] Figures 3a and 3b schematically show the front and perspective views of an optical fuse with or without an optical fiber path, wherein the movable pin is designed to cut the optical fiber.

[0044] Figure 4 Another embodiment of an optical fuse is schematically shown, in which the path of the optical fiber is indicated by dashed lines, and the optical fiber is designed to be cut by a cable;

[0045] Figure 5 A catcher mounted on a column with supporting pulleys is shown schematically;

[0046] Figure 6A catcher mounted on a column with a compression pulley is shown schematically.

[0047] Figure 7 The column head with multiple optical fuses is schematically shown. Detailed Implementation

[0048] An embodiment of cable transport equipment 1 has been described. Figure 1 and Figure 2 As shown in the diagram, the device 1 includes an overhead cable 2 connecting two terminals 3a and 3b. The overhead cable 2 can be a traction cable only, a transport cable only, or a transport-traction cable only. A traction cable 2 is designed to traction one or more carriages but not to support the weight of the carriages; a transport cable 2 is configured to transport carriages but not to traction one or more carriages. A transport-traction cable is designed to support the weight of the carriages and traction the carriages between the two terminals 3a and 3b.

[0049] Cable transport equipment can be used to transport people or goods. This equipment may include one or more terminals, also known as stations.

[0050] Device 1 can be of any type, such as Figure 1 The devices shown are single-cable or double-cable, with fixed or detachable grippers, and have continuous or reciprocating cables. Single-cable devices include a single cable for carrying and traction, while double-cable devices include at least one traction cable and at least one carrying cable. Fixed-grip devices include cars permanently attached to the traction cable, while detachable-grip devices include cars detachably attached to the traction cable. Continuous-cable devices include a traction cable that defines a closed loop between two terminal stations, and the cars run continuously along the traction cable. Reciprocating devices include cars that travel back and forth between two terminal stations along the same track.

[0051] exist Figure 1 and 2 In the specific embodiment shown, device 1 includes two terminal stations 3a and 3b, or loading / unloading stations, for loading and unloading people or goods in a carriage (not shown). Device 1 also includes drive stations 3a / 3b equipped with motors to drive a bull-wheel to move the traction cable 2. Device 1 may include return stations 3b / 3a, which include return pulleys for tensioning the traction cable 2. Advantageously, the carriage is coupled to the traction cable 2. Preferably, the cable is located above the carriage and above the ground. However, devices that traction the carriage via a cable located below the carriage are also conceivable, for example, for carriages running on rails and / or wheels.

[0052] Each car of device 1 includes an attachment device for attaching the car to the traction cable 2. The attachment device may be a fixed or detachable gripper.

[0053] Using a transport traction cable is particularly advantageous.

[0054] The equipment 1 also includes a structure 4 in which one or more cables 2 run. The structure 4 is a vertical structure for supporting the cables 2. The structure 4 may be a pole, i.e., a pole located between loading and / or unloading stations.

[0055] Post 4 can perform support, compression, or horizontal offset of the traction cable. Structure 4 can also be an internal support structure located at terminal stations 3a, 3b, or intermediate stations (not shown), also referred to as an internal support post. Cable 2 defines the path connecting stations 3a and 3b to each other.

[0056] Generally, structure 4 includes at least one pulley 5, preferably multiple pulleys 5. The pulley is a wheel with grooves designed to receive the cable 2. Regardless of the structure, the cable 2 rests on the pulley 5.

[0057] The pulley 5 is mounted so that it can rotate about the main axis of rotation. The main axis of rotation is advantageously a horizontal axis, that is, the pulley 5 is a compression pulley or a support pulley, and the carriage can move up and down.

[0058] To detect cable-related events, also known as cable events or events on cable 2, device 1 is equipped with a detection device configured to detect movement of cable 2 outside its normal position, such as cable derailment, and accidents on one of the pulleys associated with cable 2, such as blockage of pulley 5 and / or loss of pulley 5 on post 4. Derailment of cable 2 corresponds to cable 2 slipping out of the groove of at least one pulley 5, i.e., leaving its predetermined position. Depending on the specific circumstances, cable 2 may fall or move upward to be preferentially captured by a catcher, or be laterally jammed by a flange plate (not shown). Loss of pulley 5 corresponds to pulley 5 floating, while blockage of pulley 5 corresponds to pulley 5 no longer being able to rotate with the movement of cable 2. Posts can be line posts or station posts.

[0059] For detecting events on cable 2, it is particularly advantageous that at least one post 4, and preferably several posts 4, are provided with at least one fuse element, which is an optical fuse 6. Preferably, each post 4 is provided with at least one optical fuse 6, which is arranged to detect events corresponding to events on cable 2, such as events selected from at least one pulley derailment, pulley 5 loss, and pulley 5 rotational obstruction. More preferably, the post 4 includes several optical fuses 6, which are configured to detect several different cable event configurations among the aforementioned events. For example, the post 4 has at least one optical fuse 6 configured to detect cable 2 derailment, at least one optical fuse 6 configured to detect pulley 5 loss, and at least one optical fuse 6 configured to detect pulley 5 obstruction.

[0060] The optical fuse is configured to change state between a first state and a second state when the at least one fuse 6 is mechanically compressed by the cable 2. The first state allows optical signals to pass through, while the second state blocks the signals.

[0061] One or more optical fuses 6 are connected to a transmitter device 7, which is configured to transmit signals designed to pass through one or more optical fuses 6 to a receiver device 8 configured to receive signals that have passed through one or more optical fuses 6.

[0062] To improve efficiency, the optical fuse 6 includes at least one optical fiber 11, the optical attenuation value of which varies depending on the state of the optical fuse 6.

[0063] Existing technologies use conductive wires, such as copper wires, whose electrical properties vary significantly with temperature and aging. The optical performance of fiber optic cable 11 is less dependent on climatic conditions, especially temperature. It is also evident that fiber optic cables are non-conductive, making the detection device insensitive or less sensitive to lightning. Furthermore, the connection between the optical fuse 6 and the rest of the optical circuit exhibits a more favorable performance / cost ratio than its electrical equivalent. This results in the optical fuse tripping less frequently than the electrical fuse.

[0064] Because of the low attenuation of fiber 11, it is easier to detect signal loss and changes in the state of optical fuse 6, even over long distances.

[0065] In a particularly advantageous manner, when the device is in operation, the optical fuse 6 is configured to be in a first state, i.e., allowing optical signals to pass through. This configuration makes it possible to detect changes in the state of the optical fuse 6, malfunctions of the optical fuse 6, and malfunctions of the transmitter device 7. When the optical fuse 6 detects an event on the cable 2, the optical fuse 6 switches to a state that prevents optical signals from passing between the transmitter device 7 and the receiver device 8.

[0066] The optical fuse 6 is designed to operate in harsh environments, meaning it may be exposed to low temperatures, rain, ice, or sunlight, which could cause aging of electronic components and / or measurement distortion. Therefore, it is particularly advantageous to use the simpler-to-manufacture optical fuse 6. For the same reason, it is particularly advantageous to use a passive optical fuse 6, i.e., one without a power source, to avoid the need to supply power to the optical fuse 6. Using an electrically insulated optical fuse is also advantageous, making installation on posts traditionally made of metal easier.

[0067] Transmitter device 7 emits an optical signal that must pass through optical fuse 6 to reach receiver device 8. When receiver device 8 detects the absence of an optical signal, it infers that the cable has suffered an event considered dangerous and sends an alarm. The alarm transmission can be associated with the shutdown of equipment, such as the shutdown of the drive motor of cable 2. Transmitter device 7 preferably emits optical signals regularly. It is advantageous for transmitter device 7 to emit several optical signals per second.

[0068] In one configuration, the optical fuse 6 can be reset, i.e., when an operation is performed on the column to check for derailment, the action allows the optical fuse to be switched back to its initial state.

[0069] In a particular embodiment, the optical fuse 6 is a non-resettable fuse, i.e., an optical fuse 6 that accepts only one state change. Preferably, the optical fuse 6 is configured to switch only from a first state that allows optical signals to pass through to a second state that does not allow signals to pass through once an event such as derailment occurs. This configuration ensures that after an event is detected, the post will necessarily be operated to operate the optical fuse. For example, the optical fuse 6 can be configured as a single-use fuse, such that the tripping of the latter necessarily requires replacement of the optical fuse 6.

[0070] Because the optical fuse 6 is designed to operate in corrosive environments, its robustness and ability to detect incident light and interrupt communication are particularly advantageous. It is also advantageous that the optical fuse 6 is not powered. Furthermore, it is advantageous that the optical fuse 6 does not include a movable reflector and / or spring.

[0071] To obtain reliable detection of events on the cable, such as derailment of cable 2 relative to pulley 5 of post 4, multiple optical fuses 6 are installed on each post 4 along the cable wiring loop.

[0072] exist Figure 1In the specific configuration shown, each post 4 is associated with a specific optical line 9. In other words, the optical line 9 comprises only a single post 4 or is associated with only a single post 4. The optical line 9 may have a specific transmitter device 7 and receiver device 8, but it is advantageous to combine these devices to monitor several optical lines. The transmitter device 7 transmits optical signals to several posts 4 via several different optical lines. The receiver device 8 receives optical signals from several posts 4 via multiple optical lines 9. The receiver device 8 is able to identify faulty posts.

[0073] When an event occurs on cable 2 at post 4, receiver device 8 no longer receives signals from the associated optical line 9, which allows for rapid identification of the faulty post 4. In this configuration, it is particularly advantageous to connect optical fuses 6 in series so that optical fuses 6 in an open state can be detected quickly, and thus the location and / or type of event can be assessed.

[0074] When the optical fuse 6 is in the open state, the end of the optical fiber 11 assembled in the optical fuse exhibits a fault, such as a fault reflecting a portion of the transmitted signal. By using an optical pulse reflection or reflection measurement device, the reflected light can be analyzed relative to the transmitted light, and the fault, attenuation, and their distance can be determined. This allows the exact location of the faulty fuse on post 4 to be determined, and possibly the type of event.

[0075] It is advantageous to connect multiple optical fuses 6 of the column in series on a dedicated optical circuit 9. In a variant, the multiple optical fuses of the column 4 are star-connected and connected to a scheduling device that provides optical signals to each optical fuse 6 and retrieves optical signals from each optical fuse 6. This variant is less advantageous because it requires the use of a scheduling device that must be powered.

[0076] Because the optical attenuation of optical fiber changes very little over time, it is preferred to use... Figure 2 The specific configuration shown involves multiple optical fuses 6 of device 1 connected in series. The same signal passes through multiple optical fuses until an event occurs on cable 2. A single optical line 9 connects transmitter device 7 and receiver device 8, and connects multiple optical fuses 6 in series. A single optical line connects all posts 4, thus forming a compact and reliable detection device.

[0077] By using an optical pulse reflection or reflection measurement device, the reflected light can be analyzed relative to the transmitted light, and faults and attenuations, as well as their distances, can be determined. The precise location of the faulty optical fuse 6 among the optical circuits 9 distributed on different pillars 4 can then be determined.

[0078] These two embodiments can also be combined by using several optical lines 9, each optical line 9 associated with one or more posts 4. Similarly, it is advantageous to connect the optical fuses 6 in series to detect the location of the faulty optical fuse 6 using an optical pulse reflection or reflection measurement device, and to avoid installing power-consuming dispatching devices on the posts 4.

[0079] Different optical fuses can be mounted on post 4 to detect derailment on different pulleys. The position of optical fuse 6 relative to pulley 5 depends on the construction of post 4. If pulley 5 is a support pulley, which prevents cable 2 from falling, then it is preferable to mount the optical fuse below the intended position of the cable. On the other hand, if pulley 5 is a compression pulley, which prevents cable 2 from moving upward, then it is preferable to mount the optical fuse above the intended position of cable 2. To detect that the cable has disengaged from the pulley's groove in a direction that will not cause the cable to fall, such as lateral movement of cable 2 upward against the flange plate, it is preferable to place optical fuse 6 outside the axis corresponding to the normal position of the cable. In this way, when the cable leaves its position, it mechanically compresses optical fuse 6, for example, by contacting optical fuse 6, causing optical fuse 6 to trip. In this particular case, the optical fuse will be cut by the cable with the cut optical fiber. In another embodiment, the cable 2, sliding out of the pulley 5, applies a load to the moving member, thereby mechanically compressing the optical fuse 6. The cable 2, emerging from the groove, applies stress to the optical fuse 6 through an intermediate member. When the cable 2 mechanically compresses the intermediate member, for example, when it strikes the intermediate member, the latter mechanically compresses the optical fuse 6 and causes a change in state.

[0080] To facilitate easier detection of derailment of the cable corresponding to its exit from the groove of pulley 5, preferably, each post 4 includes a catcher 10, i.e., a support designed to receive the cable 2 that has exited pulley 5. The support 10 at least partially guides the cable that has exited pulley 5 to define its path and facilitate contact between the cable and the optical fuse 6 or the intermediate component that actuates the optical fuse.

[0081] Figure 5 and 6 Two embodiments of the catcher 10 are shown, the catcher 10 being assembled to retrieve from the support pulley ( Figure 5 ) and compression pulley ( Figure 6 The cable 2 that has detached from the cable is captured. The catcher 10 can be of any shape, as long as it can better grasp the path of the derailed cable 2 in order to detect the derailment.

[0082] An optical fuse 6 is arranged to detect the cable 2 disengaging from or from an associated pulley 5, and preferably to detect that the cable 2 has fallen onto the catcher 10. The optical fuse 6 is configured to switch from a state allowing signal passage to a state blocking signal passage when struck by the cable 2 sliding on the catcher 10. The optical fuse 6 is arranged at a distance from the groove, and preferably at a distance from the pulley 5. Figure 7 As shown, the optical fuse 6 is preferably fixedly mounted on the column 4, more preferably fixedly mounted on the pulley assembly of the column 4. Several pulleys 5 are assembled on the pulley assembly. The column 4 advantageously includes at least one pulley assembly, such as a main pulley assembly pivotally mounted on a support structure of the column, or a main pulley assembly pivotally mounted on a support structure, and one or more auxiliary pulley assemblies pivotally mounted relative to the main pulley assembly. The optical fuse 6 can be configured to detect rotation of the main pulley assembly relative to the support structure exceeding a threshold. The optical fuse 6 can also be configured to detect rotation of the auxiliary pulley assembly relative to the main pulley assembly exceeding a threshold.

[0083] Preferably, the optical fuse 6 protrudes from the catcher 10. As the cable 2 disengages from the groove of the pulley 5, the cable 2 moves until it reaches the catcher 10, such as a U-shaped catcher 10. When the cable 2 contacts the catcher 10, it slides until it reaches the optical fuse 6. Once the cable 2 contacts the optical fuse 6, it deforms the optical fuse 6, causing a change in its state.

[0084] In another embodiment, the optical fuse 6 is configured to detect a different failure mode known as "pulley loss." This failure is no longer movement of the cable 2 in a direction perpendicular to its longitudinal axis (defined by the alignment of the pulley's groove), but rather a failure where the pulley 5 moves out of its position. In this particular case, the pulley assembly, including the faulty pulley 5, becomes unbalanced, causing it to rotate beyond a threshold position. The optical fuse 6 can be configured to detect this excessive rotation of the pulley assembly. For example, when the threshold is reached, the rotational mechanical pressure of the pulley assembly compresses the optical fuse, causing it to change state.

[0085] For illustrative purposes, the pulley assembly is mounted to be rotatable about a rotation axis to define a rotation axis perpendicular to the longitudinal axis of cable 2. The fuse 6 is mounted such that rotation of the pulley assembly after an event on cable 2 causes displacement of the fuse 6 in contact with the cable. The cable extends and rubs against the optical fuse 6, which cuts the body 13 of the optical fuse 6 and then the optical fiber 11. When the optical fiber 11 is cut, or once the optical fiber 11 is cut, the receiving device 8 detects signal attenuation or the absence of an optical signal, and thereby infers that an event has occurred that can stop the drive motor of cable 2. Figure 4The configuration of the illustrated fuse 6 is particularly suitable. The cable 2 contacts the optical fuse to cut the optical fiber. The optical fuse 6 is made of a softer material than the cable 2, such that contact between the optical fuse 6 and the cable 2 causes the optical fuse 6 to be cut by the cable 2 until the optical fiber is severed.

[0086] In another configuration, it is advantageous for the pulley assembly to be unbalanced when cable 2 is not present. One pulley can be heavier than the other and / or one further from the axis of rotation of the pulley assembly than the other. Thus, when cable 2 slips off pulley 5 without reaching catcher 10, the pulley assembly rotates and changes the state of the optical fuse 6 associated with it. In this particular case, if the movement of cable 2 is incompatible with contacting catcher 10, the rotation of the pulley assembly causes a change in the state of the optical fuse 6. Rotating the pulley assembly to a threshold position causes the optical fuse 6 to change state.

[0087] In one embodiment, the optical fuse 6 is arranged between two pulleys 5, offset from the plane of the sidewalls comprising the grooves of the two pulleys. In this way, when the cable 2 is in the grooves of the two pulleys, the cable is a distance away from the optical fuse. As the cable 2 emerges from the grooves of the pulleys, it moves toward the optical fuse until it contacts the optical fuse and abrades the surface of the optical fuse, causing the optical fiber to be severed.

[0088] The device preferably includes an optical fuse 6 detachably mounted relative to the optical circuitry 9 to facilitate maintenance operations. The optical fuse 6 includes inputs and outputs, and preferably includes an internal optical fiber 11 for transmitting optical signals.

[0089] In a specific embodiment not shown, the optical fuse 6 may include a reflector movably arranged relative to the optical fiber 11 between a first position configured to reflect optical signals in the optical fiber 11 and a second position configured to prevent reflection of optical signals. The optical fuse 6 includes a pin, and the position of the reflector is defined by the position of the pin. The reflector may be mounted on the pin. The optical fuse 6 is mounted on a post such that the pin is moved by the cable when the cable leaves the groove of the pulley 5 to slide on the catcher 10. The pin is assembled to be movable relative to the body 13 of the optical fuse. In another configuration, the fuse is mounted on a post such that the pin defines the maximum permissible rotation of the pulley assembly. When the pulley assembly becomes unbalanced and reaches a threshold position, it strikes the optical fuse 6, which changes state, for example, by moving the pin and the reflector. In another configuration, rotation of the pulley assembly applies mechanical stress to the optical fuse 6, and when the rotation reaches a threshold, the optical fuse changes state.

[0090] This technical solution allows for altering the state of the optical fuse, thus blocking or allowing the optical signal flowing in the fiber optic cable 11 to pass through depending on the cable's position relative to the pulley or the pulley assembly. This enables the determination of derailment or another type of event. However, this technical solution is indeed cumbersome and expensive because it requires integrating the reflector and pin 12, both of which are mounted to be movable relative to the body 13 and / or the fiber optic cable 11. Furthermore, the reflectivity of the reflector may vary over time due to climatic conditions.

[0091] In another configuration, the optical fuse 6 has two optical fiber sections assembled to be movable relative to each other and optically connected to each other via an optical adapter. The optical fuse also includes a pin 12. The optical adapter is configured to ensure the transmission of an optical signal between the two sections of the optical fiber 11 in a first state. The position of at least one section of the optical fiber 11 is defined by the pin relative to the optical adapter. Movement of the pin causes movement of one section of the optical fiber 11, which alters the optical coupling and thus changes the signal attenuation. The optical fuse 6 can be installed as described above to detect different events on the cable, such as different types of derailment. By detecting the changes occurring in the optical coupling and the resulting attenuation introduced by the optical fuse 6, the event on the cable 2 can be determined.

[0092] To ensure operation can be performed on the affected post 4, it is particularly advantageous that the optical fuse 6 is non-resettable. The optical fuse is preferably replaced after an accident. Preferably, the optical fuse at least partially breaks when it detects an event, such as when cable 2 strikes the optical fuse 6.

[0093] To provide a compact and robust optical fuse 6, it is particularly advantageous that the optical fuse 6 has few moving parts, especially when the cable 2 slips out of the groove of the grooved wheel 5 and impacts the optical fuse 6, which is configured to cut the optical fiber 11. By cutting the optical fiber 11, the flow of optical signals is interrupted, and the optical fuse becomes non-resettable, requiring manual intervention to replace the fuse for improved safety.

[0094] To cut the optical fiber 11 within the optical fuse 6, the optical fuse 6 is particularly advantageous in that it includes the optical fiber 11 located within a body 13 and a pin 12 assembled to be movable relative to the body 13, and the pin 12 is arranged to cut the optical fiber 11 when the cable strikes the pin 12 of the optical fuse 6 and moves the pin 12. Such an embodiment is shown in FIG3, particularly in FIG3a and 3b.

[0095] Pin 12 can be installed in the path of cable 2 such that pin 12 pulls optical fiber 11 in the direction of its longitudinal axis to cut optical fiber 11 by traction by stretching it beyond its break point. Breakage of optical fiber 11 can also be achieved by another mechanical stress on optical fiber 11, such as by wrapping it around an object or by twisting it. However, these different embodiments are not the most effective in cable transport equipment under harsh weather conditions.

[0096] Advantageously, pin 12 and body 13 are arranged such that pin 12 cuts optical fiber 11 by shearing. For example, pin 12 and body 13 can form a pair of scissors to cut optical fiber 11. Pin 12 preferably moves in a direction perpendicular to the longitudinal axis of optical fiber 11 to cut optical fiber 11. Figure 3 shows two possible directions of movement of one end of pin 12 by two arrows, which cause the other end of the pin to move to cut optical fiber 11 against body 13. Figure 3 further shows the possible movements of pin relative to body 13 that lead to the cutting of optical fiber by dashed arrows.

[0097] In a particular embodiment, pin 12 is secured to body 13 by one or more deformable or breakable connectors. Applying stress exceeding a threshold to pin 12 can cause at least one connector to deform and potentially break. Pin 12 moves and severes optical fiber 11. Other modes of movement of pin 12 relative to body 13 can also result in breakage of optical fiber 11.

[0098] Pin 12 may be equipped with a blade. When cable 2 contacts pin 12, pin 12 moves, and the blade cuts optical fiber 11. The movement of pin 12 can be of any type, such as translation or rotation.

[0099] In the configuration shown in Figure 3, pin 12 and body 13 are configured to cut optical fiber 11 by shearing. Body 13 defines a groove 13a, and pin 12 is disposed in groove 13a. Optical fiber 11 extends from a portion of body 13, passes through pin 12, and extends to another portion of body 13. Pin 12 is mounted to be movable relative to body 13. When the cable contacts pin 12, pin 12 moves perpendicular to the longitudinal axis of optical fiber 11 and cuts optical fiber 11. Advantageously, pin 12 is mounted to be rotatable relative to body 13, with its axis of rotation perpendicular or parallel to the longitudinal axis of optical fiber 11 in the area to be cut.

[0100] In a preferred configuration, the optical fiber 11 extends within the body 13 on each side of the pin 12. For example, the body 13 defines a groove 13a, and the pin 12 is fitted into the groove 13a. The optical fiber 11 passes through the groove, which in turn passes through the pin 12. Rotation of the pin 12 relative to the body 13 deforms the optical fiber 11, thus cutting it. The axis of rotation of the pin 12 is located at a distance from the optical fiber 11.

[0101] In one particular embodiment, the optical fiber 11 is mounted in such a way that a loop of the optical fiber 11 is defined within the optical fuse. The optical fiber 11 is not mounted in a straight line within the optical fuse between the input and output, nor is it tensioned between the input and output.

[0102] Preferably, the optical fuse includes a body 13 defining a cavity. An optical fiber 11 is looped within the cavity. The optical fiber 11 is fixedly mounted in the cavity via two grooves 13a, which form two attachment points separated by a pin. Thus, when the pin 12 is actuated, it stretches the optical fiber until it is cut.

[0103] Advantageously, the optical fiber is mounted to move freely beyond the two attachment points. It is also advantageous that the optical fiber is coated with a material that deforms as the fiber deforms with temperature. For example, the optical fiber can be coated with an elastomer-type material. This material is flexible enough to deform, thereby absorbing a portion of the stress present due to the different deformations between the optical fiber and the body 13. The difference in thermal expansion between the optical fiber and the body 13 is insufficient to cause the optical fiber to break. This configuration allows the optical fiber to move freely or relatively freely within the cavity. Since the optical fiber 11 is capable of moving relative to the body 13, the deformation of the body 13 and the optical fiber 11 with temperature changes (thermal expansion) does not cause such deformation in the optical fiber 11 that would cause it to break. The difference in the coefficients of thermal expansion between the body 13 and the optical fiber 11 cannot cut the optical fiber 11, nor can it deform the optical fiber 11.

[0104] In the embodiment shown in Figure 3, the optical fiber 11 surrounds two protruding studs 14 within the cavity. The two studs 14 also define through-holes, allowing the optical fuse to be secured to... Figure 5 and 6 The optical fiber 11 is fixed on plate 15 as shown. When the cable contacts pin 12, pin 12 moves and applies tension to optical fiber 11, which is stretched until it breaks due to shear. This optical fuse configuration can effectively cut optical fiber 11 while being economical. This solution is particularly advantageous because no power supply to the post is required, as the optical fuse 6 is a mechanical component that uses energy provided by the cable to be observed to change its state.

[0105] In another configuration, each post includes at least one optical fuse, a transmitter device for an optical signal, and a receiver device for the signal. When the fuse switches from an on state to an off state, the optical fiber 11 can no longer transmit the optical signal, for example, the optical fiber 11 is cut. The receiver device associated with the optical fuse in the off state detects the absence of a signal and provides this information to a detection circuit, which identifies the post associated with the incident and generates an alarm. In this embodiment, the detection circuit is separate from the receiver device and is advantageously located in the terminal. This information is provided to the detection circuit, for example, in the form of an optical signal.

[0106] Advantageously, the first optical fuse is located at one end of the post, and the second optical fuse is located at the opposite end of the post along the longitudinal axis of the cable, which can be the running axis of the cable. This configuration allows for the detection of the cable emerging from the grooves of pulleys located at both ends of the post head. To detect the loss or blockage of pulleys, such as... Figure 7 As shown, it is advantageous to install an optical fuse on each pulley assembly. Preferably, the optical fuse 6 is installed to detect when the sway of the pulley assembly, including one or more pulleys to be monitored, exceeds a threshold.

[0107] To detect cable-related events, the transmitter device 7 of the detection apparatus emits an optical signal, which can be continuous, quasi-continuous, periodic, or aperiodic. The optical signal passes through one or more optical fuses 6 until it reaches the receiver device 8 located on the same optical line 9. Upon receiving the optical signal, the receiver device 8 infers that no event, such as derailment, has been detected. In a particular configuration, the optical line 9 defines a loop, and advantageously, the transmitter device 7 and the receiver device 8 are located in the same position and form, for example, two parts of the same unit. For example, the transmitter device and the second receiver are located in the drive terminal to detect accidents on all posts with fuse elements. In equipment with several stations, several transmitter devices and receiver devices may be present to separate the observation area in the cableway.

[0108] When the optical fuse 6 detects an event on cable 2, it switches to the open state, and the receiver device 8 infers that an event has occurred on cable 2. The receiver device 8 then generates an alarm that shuts off the drive motor of cable 2.

[0109] If the optical circuit 9 includes several optical fuses 6 connected in series, analysis of the optical circuit 9 by an optical pulse reflection or reflectometer allows determination of the distance to the fault, i.e., the location of the optical circuit break. The location of the optical fuses 6 can then be precisely determined, and thus the location of the faulty column can be determined, and possibly the type of event detected on the cable 2 can be determined. The use of optical signals is far more precise than the use of electrical signals.

[0110] Using an optical fuse 6 to detect events on cable 2, such as derailment of cable 2 or failure of pulley 5, is particularly advantageous because the modifications required to the existing equipment are minimal. Therefore, an optical signal detection device can replace a detection device that uses electrical signals.

[0111] An optical signal transmitter device 7 replaces the electrical signal transmitter device. An optical signal receiver device 8 replaces the electrical signal receiver device. Electrical circuitry is replaced by optical circuitry composed of optical fibers.

[0112] An optical line 9 is installed, connecting the optical signal transmitter device 7 to the optical signal receiver device 8. At least one optical fuse is installed along the optical connection 9 to detect events such as cable derailment. This at least one optical fuse 6 replaces at least one electrical fuse on the plurality of posts 4 of the device. Advantageously, the plurality of optical fuses 6 are connected in series on the same optical line 9.

[0113] It is advantageous to mount the optical fuse 6 within an optical connector that introduces optical signal attenuation. For example, at least one end of the optical fuse 6 introduces signal attenuation. The signal attenuation may be low, but high enough to be detectable.

[0114] When the optical fuses 6 are connected in series, and when one of the optical fuses 6 changes state to indicate a fault, a break in the optical circuit is detected, and the optical signal can no longer reach the sensor. It is advantageous to detect which optical fuse 6 changed state. A preferred method for detecting the position of the optical fuse 6 along the optical circuit is to use a reflection measurement technique. A transmitted signal propagates upwards to the optical fuse that blocks the optical signal and forms a reflector. The cross-section of the optical fiber reflects the transmitted signal.

[0115] The returned signal is analyzed to determine the position of the reflector, thereby determining the location of the optical fuse that changed state. In the first analysis mode, the returned signal received by the reflectometer is processed by a computing device (e.g., a computer) to determine the number of optical connectors that passed through. Each optical connector introduces interference. By calculating the number of interferences, the number of optical connectors that passed through can be determined. The location of the last optical fuse in the conducting state can be determined, thereby determining the location of the next optical fuse in the disconnected state. Since the location of the fuses along the optical path is known, it is possible to determine the location of the optical fuses before inspection and to predict the type of fault.

[0116] In the second analysis mode, the returned signal received by the reflectometer is processed by a computing device (e.g., a computer) to determine the transmission time of the optical signal. Since the medium through which the optical signal travels, i.e., the optical fiber, is known, the position of the reflector can be determined, thereby determining the position of the optical fuse that changed state. If the distance of each optical fuse relative to the reflectometer is known, it is possible to determine which fuse changed state.

[0117] In an alternative embodiment, the optical fuses are installed in series, but the fiber optic distance separating each group of two consecutive optical fuses is greater than a threshold distance, such as 1 meter. The threshold distance is defined by the resolution of the optical signal measurement device. The threshold distance corresponds to the minimum distance between two events along the fiber that allows the optical signal measurement device to distinguish between them. While the optical signal measurement device can distinguish between two events occurring on two consecutive posts because they are tens of meters apart along the fiber, it is much more difficult to distinguish between two incidents for two fuses on the same post that are a few centimeters apart.

[0118] Therefore, it is always advantageous to separate two optical fuses installed consecutively along an optical fiber by a threshold distance. For ease of installation, it is also advantageous to install two optical fuses in series along an optical fiber, separated by at least a threshold distance. Alternatively, two optical fuses can be installed consecutively along an optical fiber, separated by a threshold distance along the fiber, but physically, they are not separated from each other by a distance equal to the threshold. The determination of the optical fuse changing state is performed by calculating the time taken to receive the signal reflected by the fuse, which is designed to change state through the transmission of optical signals.

[0119] In a particular embodiment, each optical fuse is associated with a connector, which introduces attenuation of the optical signal as it passes through. In a particular configuration, the device has more optical fuses than a threshold number, enabling signal analysis to be performed using a reflectometer. It is then advantageous to divide the device into multiple optical lines, each with an optical fiber and fewer optical fuses than the threshold number. The optical fuses are connected in series.

[0120] In an advantageous embodiment, each post is associated with an optical fiber. Each post is tested independently to check for proper operation. For example, all posts are tested in less than 5 seconds, such as less than 3 seconds, less than 2 seconds, or even less than 1 second. The device is shut down when an optical fuse is detected to have changed state. When an optical fiber obstructing the flow of optical signals is identified, the post associated with the fault is quickly identified. The optical circuitry can then be advantageously supplemented with a reflectometer at the point of device shutdown to detect which optical fuse on the post has changed state. The type of fault can then be determined.

Claims

1. A cable transport device (1) comprising: Cable (2) A plurality of posts (4), each post having at least one pulley (5), the cable (2) being arranged to press against the at least one pulley (5) of the plurality of posts (4), at least one of the plurality of posts (4) having at least one fuse (6), the at least one fuse defining a first state allowing signal passage and a second state preventing signal passage. Detection devices (6, 7, 8) are configured to detect at least one event on the cable (2), the detection devices (6, 7, 8) causing a signal to flow through the at least one fuse (6) to monitor the state of the at least one fuse (6), the at least one fuse (6) being configured to change its state between a first state and a second state when the at least one fuse (6) detects the at least one event on the cable (2), and the detection devices (6, 7, 8) being configured to issue an alarm in response to detecting a change in the state of the at least one fuse (6). The feature is that the at least one fuse (6) is an optical fuse including an optical fiber (11), the detection device (6, 7, 8) includes a transmitter device (7) configured to transmit an optical signal and a receiver device (8) configured to receive the optical signal, the transmitter device (7) being connected to the receiver device (8) via the at least one optical fuse (6), and the at least one optical fuse (6) being configured to change its state when the at least one optical fuse (6) is mechanically compressed by the cable (2), the optical fiber being of an elastomer type. The material coating, wherein the at least one optical fuse (6) includes a pin (12) mounted in a movable manner to cut the fiber (11) loop when the pin (12) is mechanically pressed by the cable (2), and wherein the at least one optical fuse (6) includes the fiber (11) loop and a body (13) defining a cavity, the fiber (11) loop being mounted in the cavity around two attachment points (13a) separated by the pin (12), the at least one optical fuse (6) being configured to detect derailment of the cable (2) by means of the pin (12).

2. The cable transport equipment (1) according to claim 1, wherein, The at least one optical fuse (6) is configured to cut the optical fiber (11) when the at least one optical fuse (6) is mechanically pressed by the cable (2).

3. The cable transport equipment (1) according to claim 2, wherein, The at least one optical fuse (6) is configured to cut the optical fiber (11) by shearing when the at least one optical fuse (6) is mechanically compressed by the cable (2).

4. The cable transport equipment (1) according to claim 1, wherein, The optical fiber (11) loop passes through the pin (12) along the first axis.

5. The cable transport equipment (1) according to claim 4, wherein, The pin (12) is installed so that it can rotate about a rotation axis that is perpendicular to the first axis and at a certain distance from the first axis, so as to cut the optical fiber (11) loop.

6. The cable transport equipment (1) according to claim 1, wherein, The at least one event on the cable is selected from the following events: the cable (2) derails from at least one of the pulleys (5), the loss of at least one of the pulleys (5), or the blockage of at least one of the pulleys (5).

7. The cable transport equipment (1) according to claim 1, wherein, Each post (4) includes a catcher (10) designed to receive a cable (2) detached from the at least one pulley (5), and wherein the at least one optical fuse (6) protrudes from the catcher (10) to be struck by the cable (2) and to detect derailment of the cable (2), and / or wherein the catcher (10) has a movable portion connected to the at least one optical fuse (6) to mechanically compress the at least one optical fuse (6) when the movable portion is struck by the cable (2).

8. The cable transport equipment (1) according to claim 2, wherein, The mechanical pressure of the cable (2) on the at least one optical fuse (6) is achieved through direct contact between the at least one optical fuse (6) and the cable (2) and the cutting of the at least one optical fuse (6) by the cable (2).

9. The cable transport equipment (1) according to claim 1, wherein, The at least one optical fuse (6) is arranged to detect a missing or blocked pulley, and the at least one optical fuse (6) is functionally connected to the pulley assembly of the plurality of posts (4) to change the state when the pulley assembly rotates beyond a threshold.

10. The cable transport equipment (1) according to claim 1, wherein, The at least one optical fuse (6) includes a plurality of optical fuses (6) connected in series on an optical line (9) and is designed such that an optical signal can flow through the plurality of optical fuses (6), each optical fuse (6) initially being in a first state, wherein the detection device (6, 7, 8) includes a determining device configured to determine the position of one of the plurality of optical fuses (6) being in a second state when an event on the cable (2) has been detected.

11. The cable transport equipment (1) according to claim 10, wherein, The determining device is configured to calculate the transmission time of the emitted optical signal reflected by the cut optical fiber in order to determine the position of the optical fuse (6) in the second state.

12. The cable transport equipment (1) according to claim 10 or 11, wherein, Each of the optical fuses is connected to the optical circuit via a connector that introduces at least one interference, and wherein the determining device is configured to calculate the number of interferences experienced by the optical signal in order to determine the position of the optical fuse (6) in the second state.

13. The cable transport equipment (1) according to claim 1, wherein, Each column (4) includes: The control box is powered and connected to a control circuit via optical lines (9), the control circuit being configured to issue an alarm. Multiple optical fuses (6) are connected to the control box, which includes a transmitter device (7) and a receiver device (8).

14. A method for detecting events on a cable (2) in a cable transport device (1), comprising at least the following steps: A cable transport device (1) is provided, comprising a cable (2) and a plurality of posts (4), each post being provided with at least one pulley (5), the cable (2) being configured to press the at least one pulley (5) of the plurality of posts (4), at least one of the plurality of posts (4) being provided with at least one fuse, the at least one fuse defining a first state that allows a signal to pass and a second state that blocks a signal from passing, the at least one fuse being configured to change the state between the first state and the second state when the at least one fuse detects an event on the cable (2); Signals are transmitted regularly through the at least one fuse; If the detection signal receiver device does not receive the signal, it infers a state change of the at least one fuse representing an event on the cable. The method is characterized in that the at least one fuse is an optical fuse (6) including an optical fiber (11), wherein the signal is an optical signal designed to pass through the at least one optical fuse (6), the receiver device is an optical receiver device (8), the at least one optical fuse (6) is configured to change state when the at least one optical fuse (6) is mechanically compressed by the cable (2), wherein the at least one optical fuse (6) includes a pin (12) movably mounted to cut the optical fiber (11) loop when the pin (12) is mechanically compressed by the cable (2), and wherein the at least one optical fuse (6) includes the optical fiber (11) loop and a body (13) defining a cavity, the optical fiber (11) loop being mounted in the cavity around two attachment points (13a) separated by the pin (12), and the at least one optical fuse (6) is configured to detect derailment of the cable (2) by the pin (12).

15. The method for detecting events on a cable (2) in a cable transport device (1) according to claim 14, wherein, Each optical fuse (6) belongs to an optical connector connected in series along the optical fiber (11), wherein each optical connector introduces interference to the optical signal as the optical signal passes through the optical connector, the method comprising reciprocating the number of interferences received to determine the number of optical connectors that pass through, and assessing the location of the optical fuses that change state.

16. The method for detecting events on a cable (2) in a cable transport device (1) according to claim 14, wherein, The optical fuses (6) are connected in series along the optical fiber (11), wherein two consecutive optical fuses (6) along the optical fiber (11) are always separated by a threshold distance, which corresponds to the minimum distance between the two optical fuses along the optical fiber, which makes it possible to distinguish them by a measuring device of the optical signal, and to determine the optical fuse in the changed state by calculating the time taken to receive the signal reflected by the fuse in the changed state.

17. A method for manufacturing cable transport equipment (1), comprising: A cable transport device (1) is provided, comprising a cable (2) and a plurality of posts (4), each post being provided with at least one pulley (5), the cable (2) being configured to press against the at least one pulley (5) of the plurality of posts (4), at least one of the plurality of posts (4) being provided with at least one electric fuse, the at least one electric fuse defining a first state that allows an electrical signal to pass through and a second state that prevents an electrical signal from passing through, the at least one fuse being configured to change state between the first state and the second state when the at least one electric fuse is mechanically pressed by the cable (2), the at least one electric fuse being connected via a conductor cable to a detection device, the detection device being configured to detect at least one event on the cable; The at least one electrical fuse is replaced with an optical fuse (6), which defines a first state that allows an optical signal to pass through and a second state that blocks the optical signal from passing through. The at least one optical fuse (6) is configured to change the state between the first state and the second state when the at least one optical fuse (6) detects an event on the cable (2). The at least one optical fuse (6) is connected to the detection device via optical lines (9). The detection devices (6, 7, 8) include a transmitter device (7) configured to emit an optical signal and a receiver device (8) configured to receive the optical signal. The transmitter device (7) is connected to the receiver device (8) via the at least one optical fuse (6). The detection devices (6, 7, 8) are configured to issue an alarm in response to detecting a change in the state of the at least one optical fuse (6). The at least one optical fuse (6) includes a pin (12) movably mounted to cut the fiber (11) loop when the pin (12) is mechanically pressed by the cable (2). The at least one optical fuse (6) includes the fiber (11) loop and a body (13) defining a cavity. The fiber (11) loop is mounted in the cavity around two attachment points (13a) separated by the pin (12). The at least one optical fuse (6) is configured to detect derailment of the cable (2) via the pin (12).

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