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

Abstract

The invention relates to a pantograph (1) for a railway vehicle, comprising a frame and an articulated frame (5) mechanically connected to the frame and a bow mechanically connected to the articulated frame, the pantograph being characterized in that it comprises a safety device (36) and an actuator (30) configured to act on the articulated frame via the safety device, the safety device being configured to selectively: - mechanically couple the actuator and the articulated frame, by means of which the articulated frame can be moved, under the action of the actuator, between a 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, by means of which the articulated frame is moved into the low position, under the effect of its own weight, independently of the action of the actuator.

Description

Title of the invention: Pantograph comprising a safety device and method implemented by such a pantograph. TECHNICAL FIELD OF THE INVENTION

[0001] The field of the invention is that of electric vehicles powered by catenary, such as electric railway vehicles (trains) or urban passenger transport vehicles (tram, metro, etc.).

[0002] 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.

[0003] The invention finds particular applications in the field of power supply for trains equipped with articulated pantographs, as well as their protection against damage. STATE OF THE ART

[0004] It is known in the prior art of techniques for automatic emergency dropping devices (also known by the English term automatic dropping device) allowing an emergency descent of a pantograph in the event of an anomaly (malfunction, shock, ...) detected at the level of one of its components.

[0005] 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 be lowered in the event of a shock.

[0006] In the case of pantographs operated by electric actuators, an emergency descent can be operated directly by the control of the electric actuator so as to lower the pantograph.

[0007] However, such automatic emergency lowering devices do not allow for taking into account all situations of abnormal operation of the pantograph, and are not necessarily triggered in all these situations.

[0008] Thus, regardless of the type of pantograph, there is a need to strengthen the safety of existing pantographs and railway vehicles, in the face of situations of abnormal operation of the pantograph which may damage the pantograph and / or its environment. Description of the invention

[0009] The present invention aims to remedy all or part of the disadvantages of the prior art mentioned above.

[0010] To this end, according to a first aspect, the invention relates to a pantograph for 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 pantograph safety device and an actuator configured to act on the articulated frame via the safety device, the safety 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 deterioration of 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 control of the actuator leading to an over-force between the bow and the catenary.

[0013] Moreover, for example in the event of an anomaly in the control of the actuator, it can thus 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 lowering device, such a device being able to equip the pantograph according to the invention.

[0016] Preferred embodiments, which are particularly convenient, are described below.

[0017] Preferably, the safety device is configured to: - receive a safety shutdown instruction, and mechanically disconnect the actuator and the articulated frame in response to receiving the safety shutdown instruction, and - mechanically couple the actuator and the articulated frame by default, in the absence of a safety instruction being received.

[0018] Preferably, the pantograph includes a control and command module configured to transmit a safety instruction to the safety device.

[0019] Preferably, the control and command module is configured to control and command the actuator, and to transmit a command to set it to safety to the safety device in case of an anomaly in the actuator control.

[0020] Preferably, the pantograph includes 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 measuring sensor is greater than a threshold force value.

[0021] Preferably, the control and command module is configured to receive a safety order from a remote transmitter of 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 receiving the safety order.

[0022] Preferably, the safety device is of the current failure type, electrically connected to a power supply, by means of which the actuator and the articulated frame are mechanically uncoupled when the safety device is not electrically powered.

[0023] Preferably, the actuator is an electric actuator.

[0024] Preferably, the safety device is a mechanical clutch coupling device comprising a driving part mechanically attached to the actuator and a receiving part mechanically attached to the articulated frame.

[0025] Preferably, the safety device is a mechanical coupling device of an electromagnetic clutch.

[0026] Preferably, the actuator comprises a linear cylinder and a crankpin which is on the one hand rotationally connected to the linear cylinder, and which is on the other hand mechanically bound to the driving part.

[0027] Preferably, the articulated frame includes a lower arm, and the pantograph further includes a pivot tube which is mechanically attached to the lower arm, as well as a pivot shaft which is rotationally connected to the frame, the pivot tube is inserted and rotationally mounted on the pivot shaft, the receiving part being mechanically attached to the pivot tube and the driving part being mechanically attached to the pivot shaft.

[0028] Preferably, the pantograph further comprises one or more lifting springs configured to support the drive of the articulated frame in said at least one high position.

[0029] According to a second aspect, the invention relates to a railway vehicle comprising a pantograph as described above.

[0030] In particular, the railway vehicle is a train.

[0031] 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 system of a safety instruction; - mechanical disengagement, by the safety device, of the actuator and the articulated frame; thanks to which 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 secured. BRIEF DESCRIPTION OF THE FIGURES

[0032] Other advantages, purposes and particular features of the present invention will become apparent from the following non-limiting description of at least one particular embodiment of the devices and methods of the present invention, with reference to the accompanying drawings, in which:

[0033] Fig. 1 is a perspective view of a pantograph according to the invention, in a high position;

[0034] [Fig.2] is a perspective view of the pantograph of [Fig.1], in a low position;

[0035] Fig. 3 is a detailed perspective view of a lower part of the pantograph of Fig. 1, from a first angle of view;

[0036] Fig. 4 is a detailed perspective view of a lower part of the pantograph of Fig. 1, from a second viewpoint;

[0037] The [Fig.5] is an exploded perspective view in particular of the safety device, the pivot tube and the pivot shaft of the pantograph of the [Fig.1];

[0038] Fig. 6 is a cross-sectional view of the lower part of the pantograph, with a substantially parallel cross-sectional plane built from the pantograph and passing through a longitudinal axis of the pivot shaft and pivot tube;

[0039] Fig. 7 is a synoptic diagram of a method for securing the pantograph, according to the invention. DETAILED DESCRIPTION OF THE INVENTION

[0040] The present description is given by way of non-limiting grammar, each feature of an embodiment being able to be advantageously combined with any other feature of any other embodiment.

[0041] It should be noted from the outset that the figures are not necessarily to scale.

[0042] Figures 1 and 2 represent a pantograph 1 for a railway vehicle such as a train or tram, respectively in a raised position in which the pantograph 1 is deployed or erected, and in a lowered position in which the pantograph 1 is folded.

[0043] In the raised position, in which the pantograph 1 is erected or deployed, the pantograph 1 can capture the electric current ensuring the power supply to a motor of the railway vehicle, via an electrically powered catenary.

[0044] It should be specified here that the pantograph 1 can adopt several different high positions, particularly depending on variations in the height of the catenary. The low position is understood here as the lowest position that the pantograph 1 can adopt, in other words, an extreme position that it adopts when it retracts under the effect of its own weight.

[0045] In the illustrated example, the pantograph 1 includes a frame 2 which is intended to be mounted on the roof of a railway vehicle.

[0046] The frame 2 may include two longitudinal members 3 extending substantially parallel to each other, and at least two cross members 4, here four in number, connecting the longitudinal members 3.

[0047] The longitudinal members 3 are intended to be fixed to the roof of the railway vehicle, for example by bolting.

[0048] The pantograph 1 shown is of the "single-arm" type and includes an articulated frame or system 5, which is configured to raise and lower a pantograph bow between at least one low position and at least one high position.

[0049] The articulated frame 5 includes a lower arm 6 and an upper arm 7.

[0050] The articulated frame 5 includes a first articulation 27 which connects in a way articulated the lower arm 6 and the upper arm 7.

[0051] On the one hand, the lower arm 6 is mechanically connected for rotation by one of its ends, called the lower end of the lower arm 6, to the frame 2 of the pantograph.

[0052] On the other hand, the lower arm 6 is mechanically connected for rotation 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.

[0053] The pantograph 1 includes a pantograph head 8 which has a second joint 9, by which the head 8 is connected to the other end of the upper arm 7, called the upper end of the upper arm 7.

[0054] The pantograph head 8 comprises a bow frame 10, and a bow 11 arranged on the bow frame 10 which rubs against the catenary when the pantograph 1 is extended. A friction strip 12, generally made of carbon, is mounted on the upper face of the bow 11, and is adapted to rub against the catenary to collect the electric current flowing through it.

[0055] In the illustrated example, the pantograph head 8 is a double-bow head, and thus comprises two juxtaposed bows 11.

[0056] In addition, all or part of the bows 11 may be fitted with horns 20 at their ex hoppers, which prevent any lateral snagging with a catenary, and its entanglement in the pantograph.

[0057] In addition, all or part of the bows 11 may include one or more suspensions 21, which are arranged between the bow 11 and the bow frame 10.

[0058] The articulated frame 5 may further include a coupling bar 18, also called a push rod, which extends in relation to the lower arm 6, and which is mechanically fixed to rotation on one side to the frame 2 and on the other side to the lower end of the upper arm 7.

[0059] 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 mechanically subjected to rotation on one side to the upper end of the lower arm 6 and on the other side to the bow frame 10 of the pantograph head 8.

[0060] This system, which is known in the art and is not described in more detail here, forms a pair of articulated parallelograms which make it possible to ensure that the pantograph head 8 is parallel to the catenary regardless of the deployed or folded position of the pantograph 1.

[0061] In the illustrated example, the pantograph 1 further includes a lifting spring 29, which is configured to act on the articulated frame 5.

[0062] The lifting spring 29 here supports the deployment of the pantograph 1.

[0063] The pantograph 1 further includes an actuator 30 which is also configured to act on the articulated frame 5.

[0064] The actuator 30 is here an electric actuator, which is for example a linear actuator electric having a cylinder body 32 and a piston 33 equipped 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.

[0065] The pantograph 1 also includes 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 configured in particular to command and control the actuator 30.

[0066] Thus, the actuator 30 can be controlled in force, 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.

[0067] Without limitation, reference may be made, for example, to French patent application FR 2307032 filed by the Applicant concerning the implementation of such a particularly convenient and efficient system and method. However, any other method known to the art and suitable for controlling the pantograph may be used.

[0068] The pantograph 1 also includes a safety device 36.

[0069] 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.

[0070] Reference is now made 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 located between the lower arm 6 and the frame 2).

[0071] As described above, the lower arm 6 of the pantograph 1 is subject to rotation to the frame 2.

[0072] The frame 2 here includes a pair of fixing wings 37 which are opposite each other and which are each fixed to a cross member 4.

[0073] On the one hand, the pantograph 1 includes a pivot shaft 38 which is mounted freely for rotation on the frame 2.

[0074] In the illustrated example, 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.

[0075] The pivot shaft 38 has, inserted respectively on each of its ends, two bearings 41, here tapered roller bearings, and each of the plates 39 has 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.

[0076] The pantograph 1 also includes a crankpin 43 which is mechanically connected to one end of the rod 34 of the piston 33 of the electric actuator 30.

[0077] Thus, when the actuator 30 acts on the crankpin 43, it exerts a lever arm on the pivot shaft 38, which pivots around the frame 2.

[0078] 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.

[0079] For example, the crankpin 43 is fitted onto the pivot shaft 38, which has a first slot 44, and the crankpin 43 includes a first key 45 which is received in the first slot 44.

[0080] The crankpin 43 has, at the level of a free end to which the piston rod 34 of the cylinder is rotationally fixed, a pair of lugs 46 each provided with an opening and the crankpin 43 also has a pivot finger 47 allowing the end of the rod 34 of the piston 33 to be rotationally fixed to the crankpin 43, and which is received in the openings of the lugs 46.

[0081] 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 comprises the frame 2, which allows a slight inclination of the cylinder body 32 when the piston rod 34 moves.

[0082] On the other hand, the pantograph 1 includes a pivot tube 49, which can be arranged around the pivot shaft 38.

[0083] The pivot tube 49 here has a length corresponding approximately to two-thirds of that of the pivot shaft 38, so that it only covers about two-thirds of the pivot shaft 38 when it is inserted onto the latter.

[0084] It should be noted that the pantograph 1 may include a cover 50 disposed 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.

[0085] In the illustrated example, the pivot tube 49 and a first portion of tube 24 of the lower arm 6 are in one piece, and are joined together for example by welding.

[0086] The pivot tube 49 has, respectively at each of its ends and inserted into these, a first and a second end piece 51.

[0087] Each of the first and second end caps 51 is provided with an opening, and the pivot tube 49 has a pair of bearings 52 which are each on one hand inserted into an opening of an end cap 51, and which are on the other hand inserted onto the pivot shaft 38.

[0088] Thus, the pivot tube 49, and therefore the articulated frame 5, can pivot freely around the pivot shaft 38.

[0089] In the illustrated example, the pivot tube 49 is equipped with a sling 53 which extends partially around the circumference of the pivot tube 49.

[0090] Here, the sling 53 has a plurality of teeth 54 provided to cooperate with a chain 55 which is included in the lifting spring 29, and which is subjected to one end of the lifting spring 29.

[0091] 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 make it pivot.

[0092] Here, in particular, the lifting spring 29 is configured to exert a torque tending to drive the pantograph 1 into its upper position, but which is nevertheless less than the torque exerted by the pantograph's own weight.

[0093] 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 however to fold back under the effect of its own weight when the actuator 30 is not acting on the pantograph 1.

[0094] In the illustrated example, the safety device 36 is a mechanical clutch device.

[0095] In particular, the safety device 36 can be actuated under the effect of an electric current, and can be of the current failure type, i.e. that the mechanical clutch device is in an open configuration in the absence of a supply current to the device, and in a closed configuration in the presence of a supply current to the device.

[0096] For example, the safety device 36 can be a mechanical device electromagnetic clutch type, preferably with teeth.

[0097] The main constituent elements of such a clutch are briefly described below.

[0098] The safety device 36 comprises a driving part 56 and a receiving part 57.

[0099] The driving part 56 is mechanically attached to the actuator 30, while the receiving part 57 is mechanically attached to the articulated frame 5.

[0100] The driving part 56 here comprises a first annular body 58 which is inserted on the pivot shaft 38.

[0101] For example, the drive part 56 has on an inner diameter a first groove 59 and a second key 60 received in the first groove 59, and the pivot shaft 38 has a second slot 61 in which the second key 60 is also received, which makes it possible to achieve a shaft-hub type connection between the pivot shaft 38 and the first annular body 58.

[0102] In addition, for example, the pivot shaft 38 has a shoulder piece 62 which is introduced and fixed on the pivot shaft 38, against which the first annular body 58 is abutted.

[0103] The driving part 56 may include a shaft nut 63 and the pivot shaft 38 may include a portion of shaft 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 portion of shaft.

[0104] The first annular body 58 is provided with a first front face 64, the normal of which is substantially parallel to a general extension direction of the pivot shaft 38.

[0105] The first front face 64 is here provided with a first set of teeth 65 comprising a plurality of teeth arranged in a circle on the first front face 64.

[0106] The receiving part 57 comprises a second annular body 66 and a third annular body 67.

[0107] The third annular body 67 is mechanically attached to the second end 51 of the pivot tube 49.

[0108] The second end piece 51 here has a flange 68 which extends radially outwards from the pivot tube 49, and the third annular body 67 is fixed, for example by screwing by means of first screws 69, to the flange 68.

[0109] The third annular body 67 is introduced on the pivot shaft 38, between the first annular body 58 and the second annular body 66.

[0110] The third annular body 67 is designed to be able to slide relative to the second annular body 66 while being coupled to the latter in rotation.

[0111] For example, the second annular body 66 is provided with second grooves 70 peripheral axial and the third annular body 67 is provided with axial claws 71 configured to be inserted into the second grooves 70.

[0112] 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 being able to be driven jointly in rotation.

[0113] The third annular body 67 has 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 extension direction of the pivot shaft 38, and similarly to the first annular body 58, a second toothing 73 on this second front face 72.

[0114] The first toothing 65 and second toothing 73 are here similar, and configured so that they can be meshed with each other so as to mechanically couple in rotation the first annular body 58 and the second annular body 66.

[0115] The first annular body 58 comprises one or more electromagnets (not shown in the figures) which are configured to establish a magnetic field when supplied with electricity, for example by means of a railway vehicle power supply (main or auxiliary).

[0116] Under the effect of such a magnetic field, the third annular body 67, which is mobile 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.

[0117] 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.

[0118] For further details concerning the design of such an electromagnetic clutch, it is possible to refer, for example, to the clutch marketed by Warner Electric (registered trademark) under the reference E320.

[0119] The safety device 36 may further include 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.

[0120] For example, the return mechanisms are formed by tension or compression springs and arranged so as to act against the force exerted by said magnetic field.

[0121] 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 mounted for rotation on the first part 74.

[0122] The first part 74 is integral with the pivot shaft 38, here being subjected to this last by means of the shaft nut 63 and the second key 60 as described above.

[0123] Here, the first part 74 includes the first toothing 65.

[0124] The second part 75 is for example mounted to rotate on the first part 74 by means of a pair of bearings (not shown in the figures).

[0125] Here, the second part 75 comprises the electromagnet(s).

[0126] The second part 75 may include 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.

[0127] 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.

[0128] 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.

[0129] The second annular body 66 can be driven in rotation with the articulated frame 5.

[0130] The third annular body 67 can be rotated with the second body annular 66, and therefore with the articulated frame 5, while being able to slide relative to the second annular body 66.

[0131] 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 joined together and can be driven jointly in rotation.

[0132] The control module 35, which may for example include a controller or microcontroller, or a computer or microcomputer, is here configured to control the opening or closing of the safety device 36.

[0133] In other words, the control module 35 here allows the power supply to be controlled or not, to be controlled, which results in coupling, respectively uncoupling, the articulated frame 5 and the actuator 30.

[0134] Preferably, by default, the control module 35 controls the power supply to the safety device 36. For example, the pantograph 1 has a relay to control the power supply to the safety device 36, the relay being configured to power the safety device 36 by default in the absence of a control signal to the relay.

[0135] The control module 35 can also be used to command and control the actuator 30.

[0136] For example, the pantograph 1 may include one or more sensors (not shown) of a force representative of the pantograph-cantenary force, that is to say of the force exerted by the bow(s) 11 relative to the catenary.

[0137] The control module 35 may include a non-volatile computer storage memory, in which instructions for executing a pantograph control method are stored.

[0138] In particular, such a control method includes a step of controlling the actuator 30 as a function of a panto-catenary force value in particular.

[0139] Alternatively, the pantograph 1 may include a control module for the control and command of the actuator 30 which is different from the control module 35.

[0140] The safety device 36 can be configured to receive a safety instruction, for example in the form of a low intensity electrical signal which controls the relay which may be included in the safety device 36.

[0141] 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 power supply to the electromagnet(s), causing the safety device 36 to switch to its open configuration.

[0142] On the contrary, when no safety instructions are 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 it takes its default state here, causing the safety device 36 to switch to its closed configuration.

[0143] The closing configuration of the safety device 36, in which the hinged frame 5 and the actuator 30 are coupled, is here the default configuration of the device.

[0144] The safety instruction is for example transmitted to the safety device 36 by the control module 35.

[0145] For example, and in particular when the control module 35 is also a control and command module for 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.

[0146] 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 an error in a control signal transmitted to the actuator, and / or an emergency stop signal of the actuator 30 which may in particular be transmitted by a remote operator.

[0147] When the pantograph has one or more sensors for measuring a force representative of the pantograph-catenary force, the control module 35 can be configured to transmit the safety instruction in the event of exceeding a threshold value of force by the pantograph-catenary force.

[0148] The control module 35 may also include communication means with an on-board computer of the railway vehicle (for example of a train system of the type "train control and management systems" called TCMS (according to the English acronym), which is remote from the pantograph 1.

[0149] For example, the means of communication may be data transmission cables connected via a data connection to an on-board computer, or may be wireless means of communication configured to be able to communicate wirelessly with an on-board computer.

[0150] 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.

[0151] Optional advantageous features of the pantograph 1 are described below.

[0152] As can be seen in particular in Figures 3 and 4, the pantograph 1 may include a retaining member 13 configured to support the head 8 of the pantograph 1 when it is in the lowered position.

[0153] For example, the retaining member 13 comprises a support 14 fixed to the frame and a U-shaped piece 15 fixed to the support 14.

[0154] The U-shaped piece 15 may have substantially elastically deformable arms, each of which may have rollers 16. This allows the passage of the bow frame 10 by elastic deformation when the pantograph 1 is moved to or from its lower position, and its retention in the U-shaped piece 15.

[0155] Furthermore, as can also be seen in Figures 3 and 4, the pantograph 1 may include a support member 17 which is provided to support the lower arm 6 when the pantograph 1 is in the lowered position.

[0156] For example, the support member 17 includes a pad made of flexible material, such as an elastomer, fixed to the frame 2 and on which the lower arm 6 can rest.

[0157] Furthermore, as can be seen in Figures 1 and 2, the lower arm 6 and the coupling bar 18 can each include at least one first insulator 22, respectively second insulator 23.

[0158] In the illustrated example, the lower arm 6 and the coupling bar 18 each include, for example, the first portion of tube 24, respectively the second portion of tube 25, between which are arranged insulating portions formed by a first insulator 22, respectively second insulator 23.

[0159] Here, the lower arm 6 comprises two first tube sections 24, and an insulator 22.

[0160] The coupling bar comprises three second tube sections 25, and two insulators 23 arranged respectively between two adjacent second portions of tube 25.

[0161] In addition, as can be seen in Figures 1 and 2, the pantograph 1 may also include a guide bar 26, allowing a power supply cable (not shown) to be guided, suitable for carrying an electric current from the catenary to the railway vehicle.

[0162] The guide bar 26 is for example mechanically fixed 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.

[0163] In addition, 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 synoptic diagram in [Fig.7].

[0164] In accordance with what is described above, process 100 comprises the steps, in particular the following steps:

[0165] - A first step 101, of reception by the safety device 36 of a safety instructions.

[0166] 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.

[0167] - A second step 102, of mechanical uncoupling, by the engagement device safety 36, of the actuator 30 and of the articulated frame 5.

[0168] For example, the disengagement includes 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 lifting the contact between the first annular body 58 and the third annular body 67 and thus switching the safety device 36 into an open configuration.

[0169] Thus, the articulated frame 5 can be moved into the lower 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 upper position despite a descent command given to it), and thus be secured against any deterioration.

[0170] It should be specified that the method 100 is in particular carried out under initial conditions of normal operation of the pantograph 1, that is to say that the railway vehicle is in use (stationary or moving) and the pantograph 1 is in the raised 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.

[0171] In the absence of any safety shutdown instruction received by the safety shutdown 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.

[0172] Particularly advantageously, the pantograph 1 can include both a fail-safe device 36, an electric actuator 30, one or more sensors for measuring a force representative of the pantograph-catenary force, and an electronic control module 35 including a non-volatile storage memory on which instructions for a safety process as described above are stored.

[0173] In such an embodiment, all the aforementioned elements, as well as the process implemented in the control module 35, can be selected so as to meet a level of safety integrity (SIL, from the English Safety Integrity Level) corresponding to safety integrity level 2 (SIL 2).

[0174] To this end, all the aforementioned elements, as well as the process implemented in the control module 35, are themselves each designed with security integrity level 2 (SIL 2), so as to form a functional chain of security integrity level 2 (SIL 2).

[0175] Achieving such a level of safety, which is not attainable 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).

[0176] Thus, a pantograph designed with elements such as those described above makes it possible in particular to satisfy the Reliability - Maintainability - Availability - Safety (RAMS) type validation studies required to allow the implementation of railway products on railway vehicles.

[0177] The pantograph 1 and the method 100 described above are particularly convenient in that they greatly improve the safety of the pantograph, especially when it is equipped with an electric actuator, and help prevent incidents. The pantograph 1 as described is particularly compact and simple in design and operation.

[0178] According to other unillustrated variants of the pantograph according to the invention:

[0179] The pantograph has a head fitted with a single bow, or with more than two bows.

[0180] The pantograph does not include any lifting spring, or more than one lifting spring.

[0181] The rising spring is a compression spring.

[0182] The electric actuator differs from a linear actuator; for example, the electric actuator is a rotary motor, for example arranged in direct drive of the shaft pivot.

[0183] The safety device is different from a current failure type device.

[0184] The safety device is a mechanical coupling device different from a clutch.

[0185] The safety device is a mechanical clutch coupling device different from an electromagnetic clutch, for example a diaphragm disc clutch.

[0186] The mechanical clutch coupling device is normally engaged, that is to say that in the absence of any demand (in particular electrical), the driving part and the receiving part are engaged, that is to say coupled.

[0187] The lower arm and / or the coupling bar does not have insulators.

[0188] The frame includes one or more insulators through which it is mounted on the roof of the railway vehicle.

[0189] The actuator is configured to rotate the pivot shaft so as to erect the pantograph when the piston rod retracts into the cylinder, in other words when the cylinder pulls on the crankpin.

[0190] The vehicle is different from a railway vehicle of the train or tram type, for example of trolleybus or metro type.

[0191] It is more generally recalled 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 couple 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 lower 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 the reception of the safety instruction, and - mechanically couple the actuator (30) and the articulated frame (5) by default, in the absence of reception of a safety instruction.

3. Pantograph (1) according to claim 2, in which 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 safety instruction to the safety device (36) 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.

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 power 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, wherein 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 an electromagnetic clutch mechanical coupling device.

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) which is inserted and rotatably mounted on the pivot shaft (38), the receiving part (57) being mechanically secured to the pivot tube (49) and the receiving part drive (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. A 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 secured.

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