Pantograph comprising a safety device and method implemented by such a pantograph

Abstract

The invention relates to a pantograph (1) for a rail vehicle, the pantograph comprising a structure and an articulated frame (5) mechanically connected to the structure, and a head mechanically connected to the articulated frame, wherein the pantograph is characterised in that it comprises a safety device (36) and an actuator (30) configured to act on the articulated frame via the safety device, and wherein the safety device is configured to selectively: - mechanically couple the actuator to the articulated frame, whereby the articulated frame can be moved, by the actuator, between a raised position in which the head is in contact with a catenary and a lowered position in which the head is brought closer to the structure; and - mechanically uncouple the actuator from the articulated frame, whereby the articulated frame moves into the lowered position, under its own weight, independently of the action of the actuator.

Description

Description Title: Pantograph comprising a safety device and method implemented by such a pantograph TECHNICAL FIELD OF THE INVENTION [1] The field of the invention is that of electric vehicles powered by catenaries, such as electric railway vehicles (trains) or urban passenger transport vehicles (tram, metro, etc.). [2] More specifically, the invention relates to a pantograph comprising a safety device, a railway vehicle comprising such a pantograph, and a safety method implemented by such a pantograph. [3] The invention finds applications in particular in the field of the electrical supply of trains equipped with articulated pantographs, as well as their protection against damage. STATE OF THE ART [4] Automatic emergency dropping device techniques are known from the prior art, allowing an emergency descent of a pantograph to be carried out in the event of an anomaly (malfunction, shock, etc.) detected in one of its components. [5] For example, in the case of pantographs operated by pneumatic actuators, an automatic emergency lowering device may include a rupture pneumatic line, causing the pneumatic system to be purged and thus the pantograph to lower in the event of an impact. [6] In the case of pantographs operated by electric actuators, an emergency lowering can be carried out directly by controlling the electric actuator so as to lower the pantograph. [7] However, such automatic emergency lowering devices do not allow for all situations of abnormal pantograph operation to be taken into account, and are not necessarily triggered in all such situations. [8] Thus, whatever the type of pantograph, there is a need to strengthen the safety of existing pantographs and railway vehicles, in the face of abnormal operating situations of the pantograph which may damage the pantograph and / or its environment. STATEMENT OF THE INVENTION [9] The present invention aims to remedy all or part of the drawbacks of the state of the art cited above.

[0010] To this end, according to a first aspect, the invention relates to a pantograph for a railway vehicle, comprising a frame and an articulated frame mechanically connected to the frame and at least one bow mechanically connected to the articulated frame, the pantograph comprising a device for securing the pantograph and an actuator configured to act on the articulated frame via the securing device, the securing device being configured to selectively mechanically couple the actuator and the articulated frame, whereby the articulated frame can be moved, under the action of the actuator, between at least one high position in which the bow is in contact with a catenary and a low position in which the bow is brought closer to the frame; and mechanically uncouple the actuator and the articulated frame, whereby the articulated frame is moved into the low position, under the effect of its own weight, independently of the action of the actuator.

[0011] Such a pantograph makes it possible to prevent any damage to the pantograph and / or the catenary in the event of an anomaly or incident at the level of the pantograph and / or the catenary, when the pantograph is in a high position.

[0012] In particular, the integrity of the pantograph and / or the catenary can be preserved in the event of an anomaly at the actuator level, for example in the event of an anomaly in the actuator control leading to an over-force between the bow and the catenary.

[0013] Furthermore, for example in the event of an anomaly in the actuator control, it can be avoided that all or part of the pantograph remains in contact with a live catenary.

[0014] The level of availability of the railway vehicle, as well as the safety of its operation, are thus increased.

[0015] In addition, the pantograph according to the invention provides additional safety compared to a pantograph equipped only with an automatic emergency descent device, such a device being able to further equip the pantograph according to the invention.

[0016] It is specified that the fact that the safety device is configured to selectively mechanically couple the actuator and the articulated frame and to mechanically uncouple the actuator and the articulated frame means in particular that the coupled or uncoupled state can be selectively chosen according to the needs of the pantograph, and in particular not only in response to the occurrence of a particular predefined event.

[0017] Preferred embodiments, which are particularly convenient, are described below.

[0018] Preferably, the safety device is configured to selectively mechanically couple the actuator and the articulated frame and to mechanically uncouple the actuator and the articulated frame in response to the reception or non-reception by the safety device of a safety instruction determined as a function of the operating state of the actuator.

[0019] In particular, the actuator may be in a so-called normal operating state, allowing adequate operation of the pantograph, or abnormal, not allowing adequate operation of the pantograph, or even presenting a risk to the physical integrity of the pantograph.

[0020] The safety instruction may be sent to and received by the safety device when the operating state of the actuator is abnormal, in response to which the safety device mechanically disengages the actuator and the articulated frame.

[0021] Preferably, the safety device is configured to: - receive a safety instruction, and mechanically uncouple the actuator and the articulated frame in response to receiving the safety instruction, and - mechanically couple the actuator and the articulated frame by default, in the absence of receipt of a safety instruction.

[0022] Preferably, the pantograph comprises a control and command module configured to transmit a safety instruction to the safety device.

[0023] Preferably, the control and command module is configured to control and command the actuator, and to transmit a safety instruction to the safety device in the event of an anomaly in the control of the actuator.

[0024] Preferably, the pantograph comprises a sensor for measuring a force representative of the force exerted by the bow relative to the catenary, and in which the control and command module is configured to transmit a safety instruction to the safety device when the force representative of the force exerted by the bow relative to the catenary measured by the measurement sensor is greater than a force threshold value.

[0025] Preferably, the control and command module is configured to receive a safety order from a transmitter remote from the pantograph, in particular from an on-board computer of the railway vehicle, and to transmit a safety instruction to the safety device in response to receipt of the safety order.

[0026] Preferably, the safety device is of the power failure type, electrically connected to a power supply, whereby the actuator and the articulated frame are mechanically uncoupled when the safety device is not electrically powered.

[0027] Preferably, the actuator is an electric actuator.

[0028] Preferably, the safety device is a mechanical clutch coupling device comprising a driving part mechanically secured to the actuator and a receiving part mechanically secured to the articulated frame.

[0029] In the context of this application, "mechanically attached" means mechanically attached, directly or indirectly, and "rotationally connected" means pivotally connected.

[0030] Preferably, the safety device is a mechanical coupling device with an electromagnetic clutch.

[0031] Preferably, the actuator comprises a linear cylinder and a crank pin which is on the one hand connected for rotation to the linear cylinder, and which is on the other hand mechanically secured to the drive part.

[0032] Preferably, the articulated frame comprises a lower arm, and the pantograph further comprises a pivot tube which is mechanically secured to the lower arm, as well as a pivot shaft which is rotatably connected to the frame, the pivot tube is introduced and rotatably mounted on the pivot shaft, the receiving part being mechanically secured to the pivot tube and the driving part being mechanically secured to the pivot shaft.

[0033] Preferably, the pantograph further comprises one or more lifting springs configured to support the driving of the articulated frame in said at least one high position.

[0034] According to a second aspect, the invention relates to a railway vehicle comprising a pantograph as described above.

[0035] In particular, the railway vehicle is a train.

[0036] According to a third aspect, the invention relates to a method for securing a pantograph, implemented by a pantograph as described above, comprising the steps of: - receipt by the safety device of a safety instruction; - mechanical decoupling, by the safety device, of the actuator and the articulated frame; whereby the articulated frame can be moved into a low position under the effect of its own weight, independently of the action of the actuator, and thus be made safe. BRIEF DESCRIPTION OF THE FIGURES

[0037] Other advantages, aims and particular characteristics of the present invention will emerge from the following non-limiting description of at least one particular embodiment of the devices and methods which are the subject of the present invention, with reference to the appended drawings, in which:

[0038] Figure 1 is a perspective view of a pantograph according to the invention, in a high position;

[0039] Figure 2 is a perspective view of the pantograph of Figure 1, in a low position;

[0040] Figure 3 is a detailed perspective view of a lower part of the pantograph of Figure 1, from a first viewing angle;

[0041] Figure 4 is a detailed perspective view of a lower part of the pantograph of Figure 1, from a second viewing angle;

[0042] Figure 5 is an exploded perspective view including the safety device, pivot tube and pivot shaft of the pantograph of Figure 1;

[0043] Figure 6 is a sectional view of the lower part of the pantograph, with a substantially parallel sectional plane of the pantograph and passing through a longitudinal axis of the pivot shaft and the pivot tube;

[0044] Figure 7 is a block diagram of a method for securing the pantograph, according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0045] This description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner.

[0046] Please note, from now on, that the figures are not necessarily to scale.

[0047] Figures 1 and 2 show a pantograph 1 for a railway vehicle such as a train or tram, respectively in a high position in which the pantograph 1 is deployed or erected, and in a low position in which the pantograph 1 is folded.

[0048] In the raised position, in which the pantograph 1 is erected or deployed, the pantograph 1 can capture the electric current providing power to a motor of the railway vehicle, via an electrically powered catenary.

[0049] It should be noted here that the pantograph 1 can adopt several different high positions, in particular depending on variations in the height of the catenary. The low position is understood here as being the lowest position that the pantograph 1 can adopt, in other words an extreme position that it adopts when it folds under the effect of its own weight.

[0050] In the illustrated example, the pantograph 1 comprises a frame 2 which is intended to be mounted on the roof of a railway vehicle.

[0051] The frame 2 may comprise two side members 3 extending substantially parallel to each other, and at least two cross members 4, here four in number, connecting the side members 3.

[0052] The side members 3 are intended to be fixed to the roof of the railway vehicle, for example by bolting.

[0053] The pantograph 1 shown is of the “single-arm” type and comprises an articulated frame or system 5, which is configured to raise and lower a bow of the pantograph between at least one low position and at least one high position.

[0054] The articulated frame 5 comprises a lower arm 6 and an upper arm 7.

[0055] The articulated frame 5 comprises a first articulation 27 which articulately connects the lower arm 6 and the upper arm 7.

[0056] On the one hand, the lower arm 6 is mechanically connected to rotate by one of its ends, called the lower end of the lower arm 6, to the frame 2 of the pantograph.

[0057] On the other hand, the lower arm 6 is mechanically connected to rotate by its other end, called the upper end of the lower arm 6, to one of the ends of the upper arm 7, called the lower end of the upper arm 7.

[0058] The pantograph 1 comprises a pantograph head 8 which comprises a second articulation 9, by which the head 8 is connected to the other of the ends of the upper arm 7, called the upper end of the upper arm 7.

[0059] The pantograph head 8 comprises a bow frame 10, and a bow 11 arranged on the bow frame 10 and which rubs on the catenary when the pantograph 1 is deployed. A friction strip 12 generally made of carbon is mounted on the upper face of the bow 11, and is adapted to rub on the catenary to capture the electric current passing there.

[0060] In the example illustrated, the pantograph head 8 is a double-bow head, and thus comprises two juxtaposed bows 11.

[0061] Furthermore, all or part of the bows 11 may be provided with horns 20 at their ends, which make it possible to prevent any lateral snagging with a catenary, and its entanglement in the pantograph.

[0062] In addition, all or part of the bows 11 may comprise one or more suspensions 21, which are arranged between the bow 11 and the bow frame 10.

[0063] The articulated frame 5 may further comprise a coupling bar 18, also called a thrust rod, which extends opposite the lower arm 6, and which is mechanically subject to rotation on the one hand to the frame 2 and on the other hand to the lower end of the upper arm 7.

[0064] The articulated frame 5 may also include a guide 19, also called a positioning rod, which extends opposite the upper arm 7, and which is secured mechanically rotatable on the one hand to the upper end of the lower arm 6 and on the other hand to the bow frame 10 of the pantograph head 8.

[0065] This system, which is known in the art and which is not described in more detail here, forms a pair of articulated parallelograms which ensure that the pantograph head 8 is parallel to the catenary regardless of the deployed or folded position of the pantograph 1.

[0066] In the illustrated example, the pantograph 1 further comprises a lifting spring 29, which is configured to act on the articulated frame 5.

[0067] The lifting spring 29 here supports the deployment of the pantograph 1.

[0068] The pantograph 1 further comprises an actuator 30 which is also configured to act on the articulated frame 5.

[0069] The actuator 30 is here an electric actuator, which is for example an electric linear cylinder having a cylinder body 32 and a piston 33 provided with a rod 34, acting on the lower arm 6 so as to drive it in rotation and thus allow the deployment or retraction of the pantograph 1.

[0070] The pantograph 1 also comprises a control module 35, which is connected by a data link in particular to the electronic and electrical components of the pantograph 1, and which is in particular configured to command and control the actuator 30.

[0071] Thus, the actuator 30 can be force-controlled, for example in response to the measurement of a panto-catenary effect, i.e. exerted by the bow 11 relative to the catenary, when the pantograph 1 is deployed and in use.

[0072] Without limitation, reference will be made, for example, to French patent application FR 2307032 filed by the Applicant with regard to the implementation of such a particularly convenient and efficient system and method. However, any other method known in the art and suitable for controlling the pantograph may be used.

[0073] The pantograph 1 further comprises a safety device 36.

[0074] The safety device 36 is configured to selectively mechanically couple the actuator 30 and the articulated frame 5, and mechanically uncouple the actuator 30 and the articulated frame 5.

[0075] We now refer in particular to figures 3 to 6 which represent in more detail a lower part of the pantograph 1 (that is to say a part situated between the lower arm 6 and the frame 2).

[0076] As described above, the lower arm 6 of the pantograph 1 is rotatably fixed to the frame 2.

[0077] The frame 2 here comprises a pair of fixing wings 37 which are opposite each other and which are each fixed to a crosspiece 4.

[0078] On the one hand, the pantograph 1 comprises a pivot shaft 38 which is mounted freely rotatable on the frame 2.

[0079] In the example illustrated, the pantograph 1 comprises a pair of plates 39 which are each mounted on one of the fixing wings 37, for example by means of bolts 40.

[0080] The pivot shaft 38 comprises, inserted respectively on each of its ends, two bearings 41, here tapered roller bearings, and each of the plates 39 comprises a central opening 42 in which a bearing 41 is received, so as to allow the pivot shaft 38 to rotate freely relative to the frame 2.

[0081] The pantograph 1 also comprises a crank pin 43 which is mechanically connected to one end of the rod 34 of the piston 33 of the electric actuator 30.

[0082] Thus, when the actuator 30 acts on the crank pin 43, it exerts a lever arm on the pivot shaft 38, which pivots around the frame 2.

[0083] Here, the actuator 30 is configured to rotate the pivot shaft 38 so as to erect the pantograph 1 when the piston rod 34 moves out of the cylinder, in other words when the cylinder pushes on the crankpin 43.

[0084] For example, the crank pin 43 is sleeved onto the pivot shaft 38, which has a first slot 44, and the crank pin 43 includes a first key 45 which is received in the first slot 44.

[0085] The crank pin 43 comprises, at a free end to which the piston rod 34 of the jack is subjected to rotation, a pair of lugs 46 each provided with an opening and the crank pin 43 also comprises an articulation finger 47 making it possible to fix the end of the rod 34 of the piston 33 to the crank pin 43 in rotation, and which is received in the openings of the lugs 46.

[0086] The cylinder body 32 of the actuator 30 is here fixed for rotation on the frame 2, by means of a rotation bearing 48 which the frame 2 comprises, which allows a slight inclination of the cylinder body 32 when the piston rod 34 moves.

[0087] On the other hand, the pantograph 1 comprises a pivot tube 49, which can be arranged around the pivot shaft 38.

[0088] The pivot tube 49 here has a length corresponding substantially to two-thirds of that of the pivot shaft 38, so that it only covers approximately two-thirds of the pivot shaft 38 when it is inserted onto the latter.

[0089] It should be noted that the pantograph 1 may comprise a cover 50 arranged on the part of the pivot shaft 38 not covered by the pivot tube 49, as well as on the safety device 36 and the actuator 30.

[0090] In the example illustrated, the pivot tube 49 and a first portion of tube 24 of the lower arm 6 are in one piece, and are secured for example by welding.

[0091] The pivot tube 49 comprises, respectively at each of its ends and introduced into the latter, a first and a second end piece 51.

[0092] Each of the first and second end pieces 51 is provided with an opening, and the pivot tube 49 comprises a pair of bearings 52 which are each on the one hand inserted into an opening of an end piece 51, and which are on the other hand inserted onto the pivot shaft 38.

[0093] Thus, the pivot tube 49, and thus the articulated frame 5, can pivot freely around the pivot shaft 38.

[0094] In the illustrated example, the pivot tube 49 is provided with a sling 53 and which extends partially around the circumference of the pivot tube 49.

[0095] Here, the sling 53 comprises a plurality of teeth 54 provided to cooperate with a chain 55 which the lifting spring 29 comprises, and which is secured to one end of the lifting spring 29.

[0096] The lifting spring 29, which is here a tension spring, can thus pull on the chain 55 and transmit, via the teeth 54 of the sling 53, a moment of force to the pivot tube 49 in order to pivot it.

[0097] Here, in particular, the lifting spring 29 is configured to exert a moment of force tending to drive the pantograph 1 into its high position, but which is however less than the moment of force exerted by the pantograph's own weight.

[0098] Thus, the lifting spring 29 is such that it can support the actuator 30 acting on the pantograph 1 during its deployment, the pantograph 1 being able to fold back under the effect of its own weight when the actuator 30 is not acting on the pantograph 1.

[0099] In the illustrated example, the safety device 36 is a mechanical clutch device.

[0100] In particular, the safety device 36 can be actuated under the effect of an electric current, and can be of the current failure type, that is to say that the mechanical clutch device is in an opening configuration in the absence of a supply current to the device, and in a closing configuration in the presence of a supply current to the device.

[0101] For example, the safety device 36 may be a mechanical clutch device of the electromagnetic clutch type, preferably with teeth.

[0102] The main constituent elements of such a clutch are briefly described below.

[0103] The safety device 36 comprises a driving part 56 and a receiving part 57.

[0104] The driving part 56 is mechanically secured to the actuator 30, while the receiving part 57 is mechanically secured to the articulated frame 5.

[0105] The driving part 56 here comprises a first annular body 58 which is inserted onto the pivot shaft 38.

[0106] For example, the driving part 56 comprises on an inner diameter a first groove 59 and a second key 60 received in the first groove 59, and the pivot shaft 38 comprises a second slot 61 in which the second key 60 is also received, which makes it possible to produce a shaft-hub type connection between the pivot shaft 38 and the first annular body 58.

[0107] Furthermore, for example, the pivot shaft 38 has a shoulder piece 62 which is inserted and fixed on the pivot shaft 38, against which the first annular body 58 abuts.

[0108] The driving part 56 may comprise a shaft nut 63 and the pivot shaft 38 may comprise a shaft portion which is threaded, the first annular body 58 thus being able to be held in translation on the pivot shaft 38 against the shoulder piece 62, by means of the shaft nut 63 screwed onto the threaded shaft portion.

[0109] The first annular body 58 is provided with a first front face 64, the normal of which is substantially parallel to a general direction of extension of the pivot shaft 38.

[0110] The first front face 64 is here provided with a first toothing 65 comprising a plurality of teeth arranged in a circle on the first front face 64.

[0111] The receiving portion 57 comprises a second annular body 66 and a third annular body 67.

[0112] The third annular body 67 is mechanically secured to the second end piece 51 of the pivot tube 49.

[0113] The second end piece 51 here comprises a flange 68 which extends radially towards the outside of the pivot tube 49, and the third annular body 67 is fixed, for example by screwing using first screws 69, to the flange 68.

[0114] The third annular body 67 is inserted onto the pivot shaft 38, between the first annular body 58 and the second annular body 66.

[0115] The third annular body 67 is provided to be able to slide relative to the second annular body 66 while being coupled to the latter in rotation.

[0116] For example, the second annular body 66 is provided with second peripheral axial grooves 70 and the third annular body 67 is provided with axial claws 71 configured to be introduced into the second grooves 70.

[0117] Thus, the second annular body 66 and the third annular body 67 form a claw or dog coupling, the second annular body 66 and the third annular body 67 thus being able to be driven jointly in rotation.

[0118] The third annular body 67 comprises a second front face 72 which faces the first front face 64 of the first annular body 58, the normal of which is substantially parallel to a general direction of extension of the pivot shaft 38, and similarly to the first annular body 58, a second toothing 73 on this second front face 72.

[0119] The first teeth 65 and second teeth 73 are similar here, and configured to be able to be engaged with each other so as to mechanically couple in rotation the first annular body 58 and the second annular body 66.

[0120] The first annular body 58 comprises one or more electromagnets (not shown in the figures) which are configured to establish a magnetic field when they are supplied with electricity, for example by means of a railway vehicle power supply (main or auxiliary).

[0121] Under the effect of such a magnetic field, the third annular body 67, which is movable in translation in an axial direction of the pivot shaft 38, can be brought closer to the first annular body 58 to close the mechanical clutch device.

[0122] Such a mechanical clutch device constitutes a current failure type device, the presence of an electric current supplying the electromagnet(s) being necessary to close the mechanical device.

[0123] For further details concerning the design of such an electromagnetic clutch, it is possible to refer, for example, to the clutch marketed by the company Warner Electric (registered trademark) under the reference E320.

[0124] The safety device 36 may further comprise one or more return members (not shown) configured to return the third annular body 67 against the second annular body 66, in other words to maintain the mechanical clutch device in an open configuration.

[0125] For example, the return members are formed by tension or compression springs and arranged so as to act against the force exerted by said magnetic field.

[0126] According to an alternative embodiment of the first annular body 58, the first annular body 58 may comprise a first part 74 and a second part 75 rotatably mounted on the first part 74.

[0127] The first part 74 is integral with the pivot shaft 38, here being secured to the latter by means of the shaft nut 63 and the second key 60 as described above.

[0128] Here, the first part 74 comprises the first toothing 65.

[0129] The second part 75 is for example rotatably mounted on the first part 74 by means of a pair of bearings (not shown in the figures).

[0130] Here, the second part 75 comprises the electromagnet(s).

[0131] The second part 75 may comprise a hooking tab 76 which is fixed to the frame 2, which allows the second part 75 to be immobilized in rotation relative to the frame 2.

[0132] In other words, the first part 74 of the first annular body 58 is integral with the pivot shaft 38, and can be driven in rotation with the latter.

[0133] The second part 75 of the first annular body 58 is fixed in rotation relative to the frame 2, and is not driven in rotation with the pivot shaft 38.

[0134] The second annular body 66 can be driven in rotation with the articulated frame 5.

[0135] The third annular body 67 can be driven in rotation with the second annular body 66, and therefore with the articulated frame 5, while being able to slide relative to the second annular body 66.

[0136] When the third annular body 67 and the first part 74 of the first annular body 58 are coupled via the teeth 65 and 73, the pivot shaft 38, the first part 74 of the first annular body 58, the third annular body 67, the second annular body and the articulated frame 5 are secured and can be jointly driven in rotation.

[0137] The control module 35, which may for example comprise a controller or microcontroller, or a computer or microcomputer, is here configured to control the opening or closing of the safety device 36.

[0138] In other words, the control module 35 here makes it possible to control, or not, the power supply to the safety device 36, which results in coupling, respectively uncoupling, the articulated frame 5 and the actuator 30.

[0139] Preferably, by default, the control module 35 controls the power supply to the safety device 36. For example, the pantograph 1 comprises a relay for controlling the power supply to the safety device 36, the relay being configured to electrically power the safety device 36 by default in the absence of a control signal from the relay.

[0140] The control module 35 can also make it possible to command and control the actuator 30.

[0141] For example, the pantograph 1 may comprise one or more sensors (not shown) of a force representative of the panto-cantenary force, that is to say the force exerted by the bow(s) 11 relative to the catenary.

[0142] The control module 35 may comprise a non-volatile computer storage memory, in which instructions are stored for executing a method of controlling the pantograph.

[0143] In particular, such a control method comprises a step of controlling the actuator 30 as a function of a panto-catenary force value in particular.

[0144] Alternatively, the pantograph 1 may comprise a control module for controlling and operating the actuator 30 which is different from the control module 35.

[0145] The safety device 36 may be configured to receive a safety instruction, for example in the form of a low-intensity electrical signal which controls the relay that the safety device 36 may comprise.

[0146] When the safety device 36 receives the safety instruction, the articulated frame 5 and the actuator 30 are uncoupled, here for example by controlling the relay to cut off the electrical power supply to the electromagnet(s), causing the safety device 36 to move into its open configuration.

[0147] On the contrary, when no safety instruction is received by the safety device 36, the articulated frame 5 and the actuator 30 are coupled, here the relay is controlled to electrically supply the electromagnet(s), that is to say that it takes its default state here, causing the safety device 36 to switch to its closing configuration.

[0148] The closing configuration of the safety device 36, in which the articulated frame 5 and the actuator 30 are coupled, is here the default configuration of the device.

[0149] The safety instruction is for example transmitted to the safety device 36 by the control module 35.

[0150] For example, and in particular when the control module 35 is also a control and command module of the actuator 30, the control module 35 is configured to transmit the safety instruction in the event of an anomaly in the control of the actuator 30.

[0151] An anomaly in the control of the actuator 30 may for example correspond to an anomaly in the electrical supply of the actuator 30, and / or a error in a control signal transmitted to the actuator, and / or an emergency stop signal from the actuator 30 which may in particular be transmitted by a remote operator.

[0152] When the pantograph comprises one or more sensors for measuring a force representative of the panto-catenary force, the control module 35 can be configured to transmit the safety instruction in the event of the panto-catenary force exceeding a force threshold value.

[0153] The control module 35 may also include means of communication with an on-board computer of the railway vehicle (for example of a train system of the “train control and management systems” type known as TCMS (according to the English acronym), which is remote from the pantograph 1.

[0154] For example, the communication means may be data transmission cables connected via a data connection to an on-board computer, or they may be wireless communication means that are configured to communicate wirelessly with an on-board computer.

[0155] The control module 35 can then be configured to receive a safety order from such an on-board computer, issued manually by the action of an operator or automatically by the execution of a control program by the on-board computer, and to transmit the safety instruction to the safety device 36, in response to such a safety order.

[0156] Optional advantageous features of the pantograph 1 are described below.

[0157] As can be seen in Figures 3 and 4 in particular, the pantograph 1 may comprise a holding member 13 configured to support the head 8 of the pantograph 1 when the latter is in the low position.

[0158] For example, the holding member 13 comprises a support 14 fixed to the frame and a U-shaped part 15 fixed to the support 14.

[0159] The U-shaped part 15 may comprise branches which are substantially elastically deformable, and which may each comprise rollers 16. This allows the bow frame 10 to pass by elastic deformation when the pantograph 1 is moved to or from its lower position, and to be held in the U-shaped part 15.

[0160] Furthermore, as can also be seen in Figures 3 and 4, the pantograph 1 may comprise a support member 17 which is provided to support the lower arm 6 when the pantograph 1 is in the low position.

[0161] For example, the support member 17 comprises a pad made of flexible material, such as an elastomer, fixed to the frame 2 and on which the lower arm 6 can rest.

[0162] Furthermore, as can be seen in Figures 1 and 2, the lower arm 6 and the coupling rod 18 may each comprise at least one first insulator 22, respectively second insulator 23.

[0163] In the example illustrated, the lower arm 6 and the coupling bar 18 comprise for example each of the first tube portions 24, respectively second tube portions 25, between which are arranged insulating portions formed by a first insulator 22, respectively second insulator 23.

[0164] Here, the lower arm 6 comprises two first tube portions 24, and an insulator 22.

[0165] The coupling bar comprises three second tube portions 25, and two insulators 23 arranged respectively between two adjacent second tube portions 25.

[0166] Furthermore, as can be seen in Figures 1 and 2, the pantograph 1 may also include a guide bar 26, making it possible to guide an electrical power cable (not shown) adapted to carry an electrical current from the catenary to the railway vehicle.

[0167] The guide bar 26 is for example mechanically subject to rotation on the one hand to the lower end of the upper arm 7, and on the other hand to the frame 2, for example by means of a third insulator 28 which the pantograph 1 comprises.

[0168] Furthermore, according to one aspect, the invention also relates to a method 100 for securing a pantograph, in particular implemented by a pantograph 1 as described above, illustrated by the block diagram in FIG. 7.

[0169] In accordance with what is described above, the method 100 comprises the steps, in particular the following steps:

[0170] - A first step 101, of reception by the safety device 36 of a safety instruction.

[0171] For example, the safety instruction, which can be issued by the control module 35, can be a low intensity control signal intended to control the relay of the safety device 36.

[0172] - A second step 102, of mechanical uncoupling, by the safety device 36, of the actuator 30 and the articulated frame 5.

[0173] For example, the uncoupling comprises the step of controlling the relay so that the electromagnet(s) of the safety device 36 are no longer supplied with electricity, which has the effect of removing the contact between the first annular body 58 and the third annular body 67 and thus causing the safety device 36 to move into an open configuration.

[0174] Thus, the articulated frame 5 can be moved into the low position under the effect of its own weight, independently of the action of the actuator 30 (which may, for example, be faulty and keep the pantograph in the high position despite a descent instruction given to it), and thus be secured against any damage.

[0175] It should be specified that the method 100 is in particular executed under initial conditions of normal operation of the pantograph 1, that is to say that the railway vehicle is in use (stationary or in motion) and the pantograph 1 is in the high position, that is to say that it is erected, with the safety device 36 which is in the closed configuration, that is to say that the articulated frame 5 and the actuator 30 are mechanically coupled.

[0176] In the absence of any reception of a safety instruction by the safety device 36, the actuator 30 and the articulated frame 5 remain coupled by default, and the actuator 30 can be controlled to move the articulated frame 5 up or down as required.

[0177] In a particularly advantageous manner, the pantograph 1 can comprise both a safety device 36 of the current failure type, an electric actuator 30, one or more sensors for measuring a force representative of the panto-catenary force, an electronic control module 35 comprising a non-volatile storage memory on which instructions for a safety method as described above are stored.

[0178] In such an embodiment, all of the aforementioned elements, as well as the method implemented in the control module 35 can be selected. so as to meet a safety integrity level (SIL) corresponding to safety integrity level 2 (SIL 2).

[0179] For this purpose, all of the aforementioned elements, as well as the method implemented in the control module 35 are themselves each designed with safety integrity level 2 (SIL 2), so as to form a functional chain of safety integrity level 2 (SIL 2).

[0180] Achieving such a level of safety, which is not achievable by known state-of-the-art techniques, in particular pneumatically actuated pantographs, makes it possible to satisfy functional safety standards, in particular standards NF EN 61508 and NF EN 61511, as well as those specific to the railway sector, such as standards NF EN 50126, NF EN 50128 and NF EN 50129 (standards applicable in their most recent version on the priority date of this application).

[0181] Thus, a pantograph designed with elements such as those described above makes it possible in particular to satisfy the validation studies of the Reliability - Maintainability - Availability - Safety type (known as FMDS, or RAMS in English terminology) required to allow the implementation of railway products on railway vehicles.

[0182] The pantograph 1 and the method 100 described above are particularly convenient in that they make it possible to significantly improve the safety of the pantograph, in particular when the latter is equipped with an electric actuator, and make it possible to prevent incidents. The pantograph 1 as described is particularly compact, and simple to design and control.

[0183] According to other non-illustrated variants of the pantograph according to the invention:

[0184] The pantograph has a head fitted with a single bow, or more than two bows.

[0185] The pantograph has no lifting spring, or more than one lifting spring.

[0186] The lifting spring is a compression spring.

[0187] The electric actuator is different from a linear cylinder, for example the electric actuator is a rotary motor, for example arranged in direct drive of the pivot shaft.

[0188] The safety device is different from a power failure type device.

[0189] The safety device is a mechanical coupling device different from a clutch.

[0190] The safety device is a mechanical clutch coupling device different from an electromagnetic clutch, for example a diaphragm disc clutch.

[0191] The mechanical clutch coupling device is normally engaged, that is to say that in the absence of stress (in particular electrical), the driving part and the receiving part are engaged, that is to say coupled.

[0192] The lower arm and / or tie rod does not have insulators.

[0193] The frame has one or more insulators by means of which it is mounted on the roof of the railway vehicle.

[0194] The actuator is configured to rotate the pivot shaft so as to erect the pantograph when the piston rod retracts into the cylinder, that is, when the cylinder pulls on the crankpin.

[0195] The vehicle is different from a railway vehicle of the train or tram type, for example of the trolleybus or metro type.

[0196] It is recalled more generally that the invention is not limited to the examples described and illustrated.

Claims

Claims 1. Pantograph (1) for a railway vehicle, comprising a frame (2) and an articulated frame (5) mechanically connected to the frame and at least one bow (11) mechanically connected to the articulated frame, the pantograph being characterized in that it comprises a safety device (36) for the pantograph and an actuator (30) configured to act on the articulated frame (5) via the safety device (36), the safety device (36) being configured to selectively: - mechanically coupling the actuator (30) and the articulated frame (5), whereby the articulated frame (5) can be moved, under the action of the actuator (30), between at least one high position in which the bow (11) is in contact with a catenary and a low position in which the bow (11) is brought closer to the frame (2); and - mechanically uncoupling the actuator (30) and the articulated frame (5), whereby the articulated frame (5) is moved into the low position, under the effect of its own weight, independently of the action of the actuator (30).

2. Pantograph (1) according to claim 1, wherein the safety device (36) is configured to: - receive a safety instruction, and mechanically uncouple the actuator (30) and the articulated frame (5) in response to receiving the safety instruction, and - mechanically couple the actuator (30) and the articulated frame (5) by default, in the absence of receipt of a safety instruction.

3. Pantograph (1) according to claim 2, wherein the pantograph comprises a control and command module (35) configured to transmit a safety instruction to the safety device (36).

4. Pantograph (1) according to claim 3, in which the control and command module (35) is configured to control and command the actuator (30), and to transmit a safety instruction to the safety device (36) in the event of an anomaly in the control of the actuator (30).

5. Pantograph (1) according to any one of claims 3 and 4, in which the pantograph comprises a sensor for measuring a force representative of the force exerted by the bow (11) relative to the catenary, and in which the control and command module (35) is configured to transmit a setting instruction in safety to the safety device (36) when the force representative of the force exerted by the bow relative to the catenary measured by the measuring sensor is greater than a force threshold value.

6. Pantograph (1) according to any one of claims 3 to 5, in which the control and command module (35) is configured to receive a safety order from a transmitter remote from the pantograph, in particular from an on-board computer of the railway vehicle, and to transmit a safety instruction to the safety device (36) in response to the reception of the safety order.

7. Pantograph (1) according to any one of claims 1 to 6, wherein the safety device (36) is of the current failure type, electrically connected to a power supply, whereby the actuator (30) and the articulated frame (5) are mechanically uncoupled when the safety device (36) is not electrically powered.

8. Pantograph (1) according to any one of claims 1 to 7, wherein the actuator (30) is an electric actuator.

9. Pantograph (1) according to any one of claims 1 to 8, in which the safety device (36) is a mechanical clutch coupling device comprising a driving part (56) mechanically secured to the actuator (30) and a receiving part (57) mechanically secured to the articulated frame (5).

10. Pantograph (1) according to claim 9, wherein the safety device (36) is a mechanical coupling device of electromagnetic clutch.

11. Pantograph (1) according to any one of claims 9 and 10, wherein the actuator (30) comprises a linear cylinder and a crank pin (43) which is on the one hand rotatably connected to the linear cylinder, and which is on the other hand mechanically secured to the driving part (56).

12. Pantograph (1) according to any one of claims 9 to 11, wherein the articulated frame (5) comprises a lower arm (6), and the pantograph further comprises a pivot tube (49) which is mechanically secured to the lower arm (6), as well as a pivot shaft (38) which is rotatably connected to the frame (2), wherein the pivot tube (49) is inserted and rotatably mounted on the pivot shaft (38), the part receiving part (57) being mechanically secured to the pivot tube (49) and the driving part (56) being mechanically secured to the pivot shaft (38).

13. Pantograph (1) according to any one of claims 1 to 12, further comprising one or more lifting springs (29) configured to support the driving of the articulated frame (5) in said at least one high position.

14. Railway vehicle comprising a pantograph (1) according to any one of claims 1 to 13.

15. Method (200) for securing a pantograph, implemented by a pantograph (1) according to any one of claims 1 to 13, comprising the steps of: - (201) reception by the safety device (36) of a safety instruction, and - (202) mechanical decoupling, by the safety device (36), of the actuator (30) and the articulated frame (5); whereby the articulated frame (5) can be moved into a low position under the effect of its own weight, independently of the action of the actuator (30), and thus be made safe.

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