RAIL BRAKE SYSTEM AND RAIL VEHICLE WITH SUCH A SYSTEM

Description

Technical field of the invention

[0001] The invention relates to the field of railway vehicles. More particularly, it relates to a railway braking system for a railway vehicle.

[0002] The invention also relates to a railway vehicle incorporating such a system.

[0003] For example, the railway braking system may include a brake cylinder configured to act on vehicle braking components, such as brake discs or directly on the vehicle wheels. State of the art

[0004] Railway vehicles are generally equipped with brake cylinders, each having a piston that moves under the effect of a pressurized fluid; the movement of this piston results in a braking action such as the clamping of a brake disc between two pads, or the direct pressure of a pad against a wheel of the vehicle.

[0005] These brake cylinders also typically include a parking actuator that is activated in the event of a loss of pressure in the pressurized fluid, intentional draining, or a leak in the pneumatic system. This actuator provides braking force using one or more springs to replace the force of the fluid. Once activated, the brake remains permanently applied, allowing for maintenance to be carried out as needed, such as identifying and eliminating the cause of the pressurized fluid circuit failure, or replacing the brake linings.

[0006] However, it may be necessary, particularly during these maintenance operations, to move the railway vehicle whose actuator has been activated, and for this it is necessary to unlock the actuator.

[0007] Document EP 2 154 040 describes an actuation device for a vehicle wheel brake, this device comprising triggering means for locking the brake when an action such as those mentioned above has occurred. In particular, it is a parking or emergency brake actuator adapted to lock a railway brake cylinder. This actuator comprises a push sleeve adapted to act on said brake cylinder, a slide mounted axially within the push sleeve between a locked and an unlocked position, a piston adapted to be driven by elastic means and connected to a latching member, and a plurality of balls arranged in an opening in the sleeve between the slide and the latching member and controlled in position by a lateral surface of the slide.When the slide is in the locked position, the balls protrude from the sleeve, where they are engaged in a recess in the locking member. When the slide is in the unlocked position, they retract from the sleeve, where they are disengaged from the locking member. When the slide is locked, the locking member axially drives the thrust sleeve, and when the slide is unlocked, the locking member is axially disengaged from the thrust sleeve. The lateral surface of the slide has a locking recess for each ball to receive its engagement when the slide is locked. Each locking recess is axially oriented and has a circular arc cross-section with a radius similar to that of the ball.Thus, the ball is in contact with the surface of the locking recess on an arc-shaped line.

[0008] In document EP 2 154 040, the actuator also includes a release device adapted to push the slide back into the thrust sleeve by compressing a spring located between the slide and the thrust sleeve. The release device is thus adapted to move the slide from its locked position to its unlocked position. In particular, a maintenance technician wishing to stop the braking force exerted by the actuator, for example, to move the vehicle to its maintenance location, must release the actuator using the release device, for example, by pulling on a control cable.

[0009] In document EP 2 154 040, the unlocking device comprises a lever with a domed base and a rod extending from the base. The domed base is positioned and held between the top of the slide and an annular stop whose internal diameter is slightly smaller than that of the domed base. This unlocking device also includes means for actuating the lever. These means include a sleeve that partially encloses the rod and whose closed end is traversed by a transverse trunnion. This trunnion is connected to a return spring that tends to return the sleeve, and therefore the lever, to the axis of the slide. The actuating means also include a rod connected to the trunnion. This rod extends transversely to the slide and can be moved in translation along the direction by means of an external control element such as a handle connected to the control cable.

[0010] When a maintenance technician wishes to stop the braking force exerted by the actuator, they simply need to actuate the external control mechanism to move the rod, which, via the trunnion, causes the sleeve and therefore the lever to move. With the lever's domed base held against the annular stop, the sleeve pivots around the trunnion while the lever slides within the sleeve. The domed base tilts, causing a portion of this base to exert force on the top of the slide, pushing it back into its unlocked position. In other words, engaging the unlocking mechanism moves the slide towards its unlocked position. Each ball is then pushed by the latching mechanism and thus moves closer to the slide's axis until it is in the unlocking recess corresponding to its retracted position.The profile of each groove ensures that the corresponding ball's contact line remains arc-shaped throughout its movement. As soon as the balls reach their retracted position, the locking mechanism becomes axially disengaged from the sleeve. Having lost its grip on the balls, the locking mechanism then slides axially relative to the push sleeve. The piston then comes to a stop against the body, while the push sleeve is free to slide along its longitudinal axis. The brake cylinder piston returns to its upper position, and the brake cylinder is then in the released position.

[0011] Other actuation devices are known from documents EP 2982556 A1, FR 2 473 440, EP 0 206 520 and BE 852 864. Description of the invention

[0012] The invention relates to a railway braking system having in particular an actuation device and an unlocking device of the type described above, which is simple, convenient and economical both in its manufacture and in its use.

[0013] The invention thus relates, in a first aspect, to a railway braking system for a railway vehicle, comprising a brake cylinder configured to act on the braking components of the railway vehicle, an actuating device configured to lock the brake cylinder in a braking position and an unlocking device configured to unlock the actuating device by the actuating of a control mechanism, characterized in that the control mechanism comprises a control member movable in translation along a direction and housed in a housing of the unlocking device attached to the brake cylinder, the control member being configured to cooperate with the actuating device, and a locking member mounted movable in translation along a direction perpendicular to the direction of movement of the control member and housed in the housing of the unlocking device,the control mechanism being configured such that, when the actuating device is in a brake cylinder locking position and the control member is actuated and moved to a maintenance position in which it is configured to move the actuating device to an unlocking position, the locking member is actuated and moved to a position in which it locks the control member in position.

[0014] Thus, when a maintenance worker who has exerted an effort to move the control element in order to unlock the actuation device releases the exerted effort, then the control element remains in the maintenance position by the effect of the locking element.

[0015] The railway braking system control mechanism according to the invention is particularly simple and compact in that it combines, in the housing of the unlocking device, both the control member which cooperates with the actuation device and the locking member which cooperates with the control member.

[0016] Preferred, simple, convenient and economical features of the railway braking system according to the invention are presented below.

[0017] The unlocking device includes at least one control rod secured at one end to the control member and mounted partially protruding from the housing so as to be activated from outside the housing, for example by a handle and / or a control cable.

[0018] The control element is formed by a clevis mounted movable in a space provided in a body of the housing, between a safety position, corresponding to a locking of the brake cylinder, and a maintenance position corresponding to an unlocking of the brake cylinder, with the clevis having a central orifice configured to receive a lever of the actuation device.

[0019] The locking mechanism is formed by a U-shaped lock housed in a space provided in a body of the casing, with the lock having a bottom wall from which protrude a first arm having at its free end a first rim which can be housed in a first cavity provided in the body, and a second arm extending opposite the first arm and having at its free end a second rim which can be housed in a second cavity provided in the body.

[0020] The clevis and the lock are dimensioned so that the clevis is received at least partially in a space delimited between the first and second arms of the U-shaped lock.

[0021] The control mechanism has a pilot module provided with a pilot piston extending at least partially into the body of the housing, a pilot chamber supplied with pressurized fluid through a pilot orifice provided in the body of the housing and which is, on the one hand, in fluidic communication with a groove provided in a body of the brake cylinder and, on the other hand, in fluidic communication with the pilot chamber via a pilot line running at least in the body of the housing.

[0022] When the pilot chamber is supplied, the pilot piston is forced so that it pushes the lock so that the clevis can fit into it, the first rim is housed in the first cavity, and in this secure position of the clevis, the lever of the actuation device is received partially in a central orifice of the clevis.

[0023] When the pilot chamber is no longer supplied and the clevis is moved in translation towards its maintenance position, it comes out of the space delimited between the first and second arms of the U-lock, which is released and moved in translation by the pilot piston itself, which is actuated by a spring element, and in this maintenance position, the first rim comes out at least partially from the first cavity to come to position itself under the clevis while the second rim is housed in the second cavity, thus locking the clevis in position.

[0024] The pilot piston is mechanically secured at one end to the second arm of the lock and the pilot module further has a return element mounted around the pilot piston and configured to actuate it at a distance from the body space, towards an external hood of the pilot module, which external hood delimits with the pilot piston the pilot chamber which is supplied with pressurized fluid.

[0025] The control mechanism has a detection module equipped with at least one sensor housed in the body and configured to detect the position of the control element and / or the blocking element.

[0026] The casing is made of plastic. Alternatively, the casing can be made of cast alloy or machined metal.

[0027] The system includes a parking brake and / or service brake cylinder configured to act on vehicle braking components, such as brake discs or directly on the vehicle wheels, with the actuation device configured to lock the brake cylinder in parking brake configuration.

[0028] The invention also relates, in a second aspect, to a railway vehicle comprising a railway braking system as described above, which is configured to act on mechanical parts of the vehicle and whose unlocking device is configured to unlock the actuation device by the actuation of a control mechanism. Brief description of the figures

[0029] We will now continue the exposition of the invention by describing examples of implementation, given below by way of illustration and not limitation, with reference to the attached drawings. There figure 1 schematically illustrates a railway braking system according to the invention. figure 2 partially illustrates, in perspective, the railway braking system of the figure 1 . There figure 3 is a partial cross-sectional view labeled III-III on the figure 2 . There figure 4 is a longitudinal median cross-sectional view of a control mechanism of the railway braking system of figures 1 to 3 , in an initial, so-called security configuration. The figure 5 is a view similar to that of the figure 4 showing the control mechanism in a second configuration, known as maintenance mode. figure 6 This cross-section illustrates a first variant of the control mechanism, in its initial, so-called locked configuration. figure 7 is a view similar to that of the figure 6 showing the control mechanism in its second, so-called unlocked, configuration. figure 8This illustration shows a cross-section of a second embodiment of the control mechanism, in its first, so-called locked, configuration. figure 9 is a view similar to that of the figure 8 showing the control mechanism in its second, so-called unlocked configuration. Detailed description

[0030] There figure 1 schematically illustrates a railway braking system 1 comprising a railway brake cylinder 2 coupled to an actuation device 3, hereinafter referred to as the actuator, configured to perform a function called, for example, a parking brake or an emergency brake.

[0031] The brake cylinder 2 comprises a body 4, a brake piston 5 movable along a first axial direction inside the body 4 and delimiting with the latter a pressure chamber 6 on the side of which the actuator 3 is coupled.

[0032] The brake cylinder 2 further comprises a push rod 7 movable along a second axial direction perpendicular to the first axial direction.

[0033] The brake piston 5 is attached to a corner piece 8 having, for example here, a triangular section.

[0034] The corner piece 8 is configured to cooperate with a first bearing stop 9 connected to the body 4 of the brake cylinder 2 and with a second bearing stop 10 connected to the push rod 7.

[0035] The brake cylinder 2 includes an elastic element 11, here a spring, which is arranged between the body 4 and the push rod 7 in order to return the second bearing stop 10 against the corner piece 8.

[0036] The railway braking system 1 is equipped with a fluid routing network and in particular here with a first pipe 12 connecting the pressure chamber 6 via a first inlet orifice 13 to a first source of pressurized fluid marked FS on the figure 1 .

[0037] The railway braking system 1 is further equipped with a brake linkage 15 on which the brake cylinder 2 acts, and the railway brake linkage 15 is configured to act on a brake disc 16 mounted, for example, on an axle 17 of a railway vehicle, or directly on the wheel to be braked. The brake disc 16 is shown here in profile.

[0038] The linkage 15 conventionally includes two brake pads 18 arranged on either side of the brake disc 16 and which, in the absence of stress, are away from the brake disc 16 and during a braking action, are stressed by the linkage 15 against the brake disc 16 to slow down and / or stop the brake disc 16 by friction.

[0039] The steering mechanism 15 comprises for this purpose two levers 19, at least partially rigid, each having an upper and a lower arm joined together, each lever 19 being mounted for rotation about an axis 20 fixed to a chassis 21 of the railway vehicle. The lower arm of each lever 19 is connected to one of the brake pads 18. The upper arm of each lever 19 is connected to a joint 22.

[0040] The brake cylinder 2 is mounted between the two joints 22, the body 4 being fixed to one of these joints 22 and the end of the push rod 7 being fixed to the other joint 22.

[0041] We will briefly describe the operation of brake cylinder 2 assuming at this stage that actuator 1, not yet described, is deactivated.

[0042] On the figure 1 The brake cylinder 2 is shown in its standby position. In this position, the fluid pressure FS is not exerted; that is, the first line 12 is, for example, at atmospheric pressure. The pressure chamber 6 then has a minimal volume, with the spring 11 exerting pressure on the second bearing stop 10 towards the first bearing stop 9, causing the wedge piece 8 and the brake piston 5 to rise.

[0043] When the brake cylinder 2 is in the braking position, the first line 12 receives pressurized fluid FS, which fills the pressure chamber 6 and forces the brake piston 5 and the wedge piece 8 downwards. This causes the first and second stops 9 and 10, and therefore the joints 22, to separate. The volume of the pressure chamber 6 is at its maximum in this position. As soon as the pressure of the fluid FS is released from the first line 12, the brake cylinder 2 returns to its resting position under the action of the spring 11, expelling the fluid from the pressure chamber 6.

[0044] As regards the actuator 3, it comprises a body formed with the body 4 of the brake cylinder 2, which may comprise several parts mechanically and securely fastened to one another.

[0045] The actuator 3 has an opening 23 arranged opposite the brake piston 5 and opening into the pressure chamber 6 of the brake cylinder 2.

[0046] The opening 21 is here a circular opening partially receiving by sliding a locking device 14, here ball 24, of the actuator 3.

[0047] The actuator 3 includes an additional braking piston 25 mounted movable in the body 4 and delimiting with the latter an additional pressure chamber 26 through which the locking device 14 extends.

[0048] The fluid routing network includes a second pipe 27 connecting the supplementary pressure chamber 26 via a second inlet port 28 to a second pressurized fluid source marked FP on the figure 1 .

[0049] The auxiliary brake piston 25 is movable between a high and a low position. The schematic view of the figure 1 shows piston 24 in the upper position.

[0050] The additional brake piston 25 has in its center an orifice through which the locking device 14 passes. The seal between the locking device 16 and the piston 24 is ensured by a gasket.

[0051] Elastic elements 29, formed in this example by springs, constantly drive the additional braking piston 25 towards its lower position.

[0052] In normal operation, the auxiliary pressure chamber 26 is supplied with pressurized fluid FP so that the auxiliary brake piston 25 is in the raised position. In the event of a fault, for example in the pneumatic lines, or in the event of emergency braking, or application of the parking brake, etc., the auxiliary pressure chamber 26 is no longer supplied and the springs 29 push the auxiliary brake piston 25 to the lowered position, generating a displacement of the locking device 16 and locking the brake piston 5 in a braking position, for example, the parking position.

[0053] The railway braking system 1 is further equipped with a pneumatic distribution unit, formed here by an anti-overlap valve 30 which is configured to prevent the application of both the parking brake and the service brake, which could damage the brake cylinder 2 and in particular the push rod 7.

[0054] In particular, the anti-overlap valve 30 is crossed on one side by the second pipe 27 normally supplied with pressurized fluid FP and on the other side connected to the first pipe 12 normally supplied with pressurized fluid FS.

[0055] Thus, if the first pipe 12 is supplied with pressurized fluid FS and the second pipe 27 is open to the atmosphere or at least is not supplied with sufficient pressure to hold the springs 29, then it is the pressurized fluid FS which flows through the anti-overlap valve 30 and which holds the springs 29 to prevent them from applying an additional braking force to that already applied by the pressurized fluid FS on the brake piston 5.

[0056] The actuator 1 further includes an unlocking device 50 which is configured to push back the locking device 14 or, in other words, to move it from a locked position to an unlocked position.

[0057] The unlocking device 50 is also supplied with pressurized fluid FP by a third pipe 31 through a third orifice 32 provided in the body 4, with the third pipe which is connected to the second pipe 27.

[0058] The unlocking device 50 is also called a retention device, or valve.

[0059] There figure 2 illustrates in perspective the railway braking system 1 and in particular the brake cylinder 2 and the actuator 3 and the figure 3 a partial cut showing actuator 3.

[0060] The unlocking device 50 is provided with a separate housing 33 and is mechanically attached to the body 4 of the brake cylinder 2

[0061] The unlocking device 50 is further provided with a plurality of control rods 34 mounted partially protruding from the housing 33 and to which are connected at one end control cables (not shown) and a control handle 35.

[0062] The unlocking device 50 is provided with a control mechanism 40 housed in a space 39 provided in the housing 33 and mechanically attached to an opposite end of the control rods 34 (see below for more details with reference to figures 4 And 5 ).

[0063] On the figures 2 And 3 Also visible is the first pipe 12 supplying the brake cylinder 2 with pressurized fluid FS, and the anti-overlap valve 30 which is here directly formed in the body 4.

[0064] The anti-overlap valve 30 includes, in particular, a pressurized fluid inlet FS 36 and a pressurized fluid inlet FP 37, as well as an internal channel 38 formed in the body 4 to channel the pressurized fluid FP to the unlocking device 50 ( figure 2 ).

[0065] The internal channel 38 has a first portion extending into the body 4 along the first axial direction and a second portion also extending into the body 4 along the second axial direction perpendicular to the first direction, until it opens into a fluidic communication groove 41 formed on the surface of the body 4 against the housing 33 of the unlocking device 50 ( figure 3 ).

[0066] In the illustrated example, the fluidic communication throat 41 is circular.

[0067] There figure 3also shows in more detail the locking device 14 of the actuator 1.

[0068] In particular, in the illustrated example, the locking device 14 comprises a push sleeve 42 that fits tightly into the opening 23 by means of an O-ring, and a slide 43 arranged inside the push sleeve 42 so as to be movable between an upper and a lower position. It is shown here in the upper position, corresponding to the locking position, while its lower position corresponds to the unlocking position.

[0069] The slide 43 is constantly forced towards its locking position by a spring 44 arranged between the slide 43 and the push sleeve 42.

[0070] The actuator 1 further comprises a latching member 46, here formed as a single unit with the complementary braking piston 25, and which at least partially encloses the thrust sleeve 42. This latching member 46 comprises a first annular portion surrounding the thrust sleeve 42 and having an internal diameter similar to the latter, so that it can slide along it. The latching member 46 also comprises a second annular portion having a larger internal diameter, thus forming a recess. The two portions are connected to each other by a flared intermediate portion, forming a toroidal bearing surface on the inner side.

[0071] The actuator 1 comprises several balls 24, each at least partially disposed in the thrust sleeve 42 between the slide 43 and the latching member 46. The balls 24 are configured to occupy a protruding position corresponding to the locking position of the slide 43 and a retracted position corresponding to the unlocking position of the slide 43.

[0072] When the slide 43 is in the locking position, the hooking member 46 is able to axially drive the thrust sleeve 42 via these balls 24. Conversely, when the slide 43 is in the unlocking position, the hooking member 46 is axially disengaged from the thrust sleeve 42.

[0073] The slide 43 has at its end opposite the spring 44 a lateral surface which is for example formed of receiving grooves 45 each extending along the axis of this slide 43.

[0074] It should be noted that functionally, the unlocking device 50 is configured to push the slide 43 into the thrust sleeve 42 by compressing the spring 44.

[0075] The unlocking device 50 is therefore adapted to move the slide 43 from its locking position to its unlocking position, by pulling on the handle 35 and therefore on the control rod 34.

[0076] In particular, in the illustrated example, the unlocking device 50 comprises a lever 47 formed by a rod having at one end a domed base 48 whose concavity is turned towards the slide 43 and from which the rod extends. The domed base 48 is here disposed and held between the top of the slide 43 and an annular stop 49, while the rod extends from the domed base 48 and is housed in a sleeve 51, one end of which is housed in the space 39, or recess, of the casing 33 and by which the sleeve 54 is articulated by a pivot 52.

[0077] It is therefore the control mechanism 40 which is configured to actuate the lever 47 by articulating the sleeve 51 at the pivot 52.

[0078] Indeed, when the maintenance worker wishes to stop the braking force exerted by the actuator 1, he simply needs to operate the handle 35 so as to move the control rod 34, the latter causing the movement of the sleeve 51 and therefore of the lever 47. The domed base 48 of the lever 47 being held against the annular stop 49, the sleeve 51 pivots around the pivot 52, or trunnion, while the lever 47 slides in this sleeve 51 and the domed base 48 tilts so that a part of the latter exerts a force on the top of the slide 43 which is pushed back into its unlocked position.

[0079] We will now describe in more detail the control mechanism 40 and more generally the housing 33 of the unlocking device 50 with reference to figures 4 And 5 .

[0080] The case 33 has a body 60 which is here made at least partially of plastic.

[0081] The housing 33 has a plate 53, for example made of plastic or metal, and mechanically secured to an upper face of the body 60 by means of fastening elements 54, for example of the screw type.

[0082] The control rods 34, three in number in the illustrated example, protrude through holes made in the plate 53.

[0083] The handle 35 is mechanically attached to one of the control rods 34, located in the center.

[0084] On another of the control rods 34, located on one side, is mechanically attached a control cable 55 formed of a core 58 at least partially wrapped by a sheath 56 and having at a free end a mounting member 57, of the nut type, configured to be mechanically attached to a complementary mounting member 59 mounted on the plate 53. Such a control cable 55 can be configured to pull and / or push the associated control rod 34.

[0085] On the other of the control rods 34, located on an opposite side, a control cable of the same type as that described above can be mechanically attached.

[0086] The control mechanism 40 also has a control module 61 made here at least partially of metal and mechanically secured to one side of the body 60 of the housing 33 by means of fastening elements 54, for example of the screw type.

[0087] In the illustrated example, the control mechanism 40 also has a detection module 62 made at least partially of plastic or metal, and here also mechanically secured on an opposite side of the body 60 of the housing 33 by means of fastening elements 54, for example of the screw type.

[0088] Space 39, or housing, is here made in the body 60 of the case 33.

[0089] The control rods 34 extend into the body 60 and protrude into this space 39.

[0090] The control mechanism 40 is provided with a control element, here a clevis 63 which is mounted movable in a direction in the space 39 in the body 60 of the housing 33, between a so-called safety position ( figure 4 ), corresponding to a brake cylinder lock, and a so-called maintenance position ( figure 5 ) corresponding to an unlocking of the brake cylinder.

[0091] The clevis 63 has a central opening 66 configured to receive the sheath 51 of the lever at the pivot 52 for the articulation of the latter.

[0092] In the safety position of the clevis 63, the sleeve 51 of the lever of the unlocking device 50 is received in the central orifice 66 of the clevis 63.

[0093] In the maintenance position of the clevis 63, the latter rotates the sleeve 51 of the lever of the unlocking device 50, which can then come out of the central orifice 66 of the clevis 63.

[0094] The control rods 34 are mechanically attached to the clevis 63.

[0095] The control mechanism 40 has at least one return member 65 mounted here around the control rod 34 located in the center, between the plate 53 and the clevis 63.

[0096] The return element 65 is here formed by a spring configured to stress the clevis 63 in its so-called safety position.

[0097] Thus, when the maintenance worker pulls on the handle 35, the clevis 63 is moved in translation in the housing 39 towards its maintenance position and, when the maintenance worker releases the handle 35, the clevis 63 is stressed in the opposite direction and is moved in translation in the housing 39 towards its safety position, unless the clevis 63 is held in the maintenance position.

[0098] In particular, the control mechanism 40 is further provided with a locking element, here a U-shaped lock 64 housed in the space 39 of the body 60 of the casing 33.

[0099] The lock 64 is mounted to move in translation along a direction perpendicular to the direction of movement of the clevis 63 in space 39 in the body 60.

[0100] The lock 64 has a bottom wall 67 from which protrudes a first branch 68 having at its free end a first rim 69 which can be housed in a first cavity 72 provided in the body 60, and a second branch 70 extending opposite the first branch 68 and having at its free end a second rim 71 which can be housed in a second cavity 73 provided in the body 60.

[0101] The lock 64 also has a protrusion 74 projecting from the bottom wall 67 and / or the first branch 68 and extending to the detection module 62.

[0102] The detection module 62 has at least one sensor 75 housed in the body 60 and configured to detect the presence or absence of the protrusion 74 and a connection socket 76 for retrieving information, for example electrical, representative of the position of the lock 64 in the control mechanism 40.

[0103] The pilot module 61 has a pilot piston 77 extending at least partially into the body 60 of the housing 33 and mechanically secured at one end to the second arm 70 of the lock 64.

[0104] The pilot module 61 also has a return element 79 formed here by a spring mounted around the pilot piston 77 and configured to exert a remote force from the space 39 of the body 33, towards an external cover 80 of the pilot module 61.

[0105] The outer cover 80 delimits with the pilot piston 77 a pilot chamber 78 which is supplied with pressurized fluid FP by a pilot orifice 81 provided in the body 60 of the housing 33 and which is, on the one hand, in fluidic communication with the groove 41 provided in the body 4 of the brake cylinder 2 and, on the other hand, in fluidic communication with the pilot chamber 78 via a pilot line 82 running in the body 60 and in the outer cover 80.

[0106] The clevis 63 and the lock 64 are here dimensioned so that the clevis 63 can be received at least partially in a space delimited between the first and second branches 68 and 70 of the U-shaped lock 64.

[0107] In particular, when the pilot chamber 78 is powered ( figure 4 ), the pilot piston 77 is forced so that it pushes the lock 64 so that the clevis 63 can fit into it.

[0108] The protrusion 74 is then in contact with the sensor 75 of the detection module 62.

[0109] The first rim 69 is housed in the first cavity 72.

[0110] In this safety configuration, the sleeve 51 of the lever of the unlocking device 50 can be received in the central orifice 66 of the clevis 63.

[0111] If the pilot chamber 78 is no longer supplied, then the unlocking device 50 goes into locking configuration (see above).

[0112] Neither the clevis 63 nor the lock 64 are moved, and the pilot piston 77 remains in position in space 69.

[0113] If the maintenance worker pulls on the handle 35, or on a control cable 55, the clevis 63 is moved in translation towards the plate 53, coming out of the space delimited between the first and second arms 68 and 70 of the U-shaped lock 64.

[0114] The lock 64 is released and moved in translation by the pilot piston 77 itself, which is actuated by the spring 79.

[0115] In this maintenance configuration, the first rim 69 comes out at least partially from the first cavity 72 to come and position itself under the slab 63, while the second rim 71 is housed in the second cavity 73.

[0116] The clevis 63 is then locked in position, towards the plate, even when the maintenance worker releases the handle 35 or operates a control cable 55 in the opposite direction.

[0117] In a first variant of the implementation illustrated on the figures 6 and 7 The detection module 62 and the control module 61 are directly integrated into space 39 in the body 60 of the housing 33. The detection module 62 is further configured to be in contact with the clevis 63 and thus detect the position of the latter rather than the position of the lock 64.

[0118] In a second variant of the embodiment illustrated on the figures 8 and 9The control mechanism 40 lacks a detection module. Furthermore, the locking mechanism is formed directly by the pilot piston 77, which, when extended, locks the yoke 63 in position. The pilot pressure chamber 78 and the return member 79 are also reversed. In other words, in the presence of pressurized fluid FP, the pilot piston 77 is retracted and does not lock the yoke 63, while in the absence of pressurized fluid FP, the pilot piston 77 is extended and locks the yoke 63. Moreover, on the figures 8 and 9 , the return member 65 is not mounted around the control rod 34 but on the opposite side, in the space 39 between the clevis 63 and the body 60 of the housing 33.

[0119] In an unillustrated variant, the unlocking device housing may be made of metal rather than plastic, and the control module cover may be made of plastic rather than metal.

[0120] More generally, the invention is not limited to the examples described and illustrated. The invention is limited solely to the scope of the attached claims.

Claims

1. A railway braking system for a railway vehicle, including a brake cylinder (2) configured to act on braking members (18) of the railway vehicle, an actuation device (14) configured to lock the brake cylinder in a braking position and an unlocking device (50) configured to unlock the actuation device by actuation of a control mechanism (40), the control mechanism includes a control member (63) movable in translation according to one direction, characterised in that the control mechanism (40) is housed in a casing (33) of the unlocking device connected to the brake cylinder, the control member being configured to cooperate with the actuation device, and a blocking member (64, 77) mounted movable in translation according to a direction perpendicular to the direction of movement of the control member and housed in the casing of the unlocking device, the control mechanism being configured so that, when the actuation device is in a locking position of the brake cylinder and the control member is urged and moved towards a maintenance position in which it is configured to make the actuation device pass into an unlocking position, the blocking member is urged and moved into a position in which it blocks the control member in position.

2. The railway braking system according to claim 1, characterised in that the unlocking device (50) includes at least one control rod (34) connected at one end to the control member (63) and mounted so as to partially project from the casing (33) so as to be urged from the outside of the casing for example by a handle (35) and / or a control cable (55).

3. The railway braking system according to one of claims 1 and 2, characterised in that the control member is formed by a clevis (63) movably mounted in a space (39) formed in a body (60) of the casing (33), between a safety position, corresponding to locking of the brake cylinder (2), and a maintenance position corresponding to unlocking of the brake cylinder, with the clevis which has a central orifice (66) configured to receive a lever (47) of the actuation device (14).

4. The railway braking system according to any one of claims 1 to 3, characterised in that the blocking member is formed by a U-shaped lock (64) housed in a space (39) formed in a body (60) of the casing (33), with the lock which has a bottom wall (67) from which project a first branch (68) having at its free end a first flange (69) which can be housed in a first cavity (72) formed in the body of the casing, and a second branch (70) extending opposite the first branch and having at its free end a second flange (71) which can be housed in a second cavity (73) formed in the body of the casing.

5. The railway braking system according to claims 3 and 4, characterised in that the clevis (63) and the lock (64) are sized so that the clevis is received at least partially in a space delimited between the first and second branches (68, 70) of the lock.

6. The railway braking system according to any one of claims 1 to 5, characterised in that the control mechanism (40) has a control module (61) provided with a control piston (77) extending at least partially in a body (60) of the casing (33), a control chamber (78) supplied with pressurised fluid (FP) via a control orifice (81) formed in the body of the casing and which is located, on the one hand in fluid communication with a groove (41) formed in a body (4) of the brake cylinder (2) and, on the other hand, in fluid communication with the control chamber via a control line (82) running at least in the body of the casing.

7. The railway braking system according to claims 3 to 6, characterised in that when the control chamber (78) is supplied, the control piston (77) is urged so that it pushes the lock (64) so that the clevis (63) can be received therein, the first flange (69) is housed in the first cavity (72), and in this safety position of the clevis, the lever (47) of the actuation device (14) is partially received in the central orifice (66) of the clevis.

8. The railway braking system according to claims 3 to 6, characterised in that when the control chamber (78) is no longer supplied and the clevis (63) is driven in translation towards its maintenance position, it comes out from the space delimited between the first and second branches (68, 70) of the lock (64), which is released and driven in translation by the control piston (77) itself urged by a spring member (79) and, in this maintenance position, the first flange (69) comes out at least partially from the first cavity (72) to be positioned under the clevis whereas the second flange (71) is housed in the second cavity (73), thereby blocking the clevis in position.

9. The railway braking system according to any one of claims 6 to 8, characterised in that the control piston (77) is mechanically connected at one end to the second branch (70) of the lock (64) and the control module (61) further has a return member (79) mounted around the control piston (77) and configured to urge it away from the space (39) of the body (60) of the casing (33), towards an outer cover (80) of the control module, which outer cover delimits with the control piston the control chamber (78) which is supplied with pressurised fluid (FP).

10. The railway braking system according to any one of claims 1 to 9, characterised in that the control mechanism (40) has a detection module (62) provided with at least one sensor (75) housed in the body (60) of the casing (33) and configured to detect the position of the control member (63) and / or of the blocking member (64).

11. The railway braking system according to any one of claims 1 to 10, characterised in that it includes a parking brake and / or service brake cylinder configured to act on braking members of the vehicle, such as for example brake discs or directly on the wheels of the vehicle, with the actuation device (50) which is configured to lock the brake cylinder in the parking brake configuration.

12. A railway vehicle including a railway braking system according to any one of claims 1 to 11, which is configured to act on mechanical members (18) of the vehicle and the unlocking device (50) of which is configured to unlock the actuation device (14) by actuation of a control mechanism (40).