Sealing ring with locking mechanism against translational movement

Description

[0001] The present invention relates to the braking of railway rolling stock and in particular to the friction assemblies of the braking systems of railway rolling stock. Such equipment is understood to mean all vehicles configured to run on rails, such as trains, trams, and metros.

[0002] The braking system generally comprises a disc secured to a wheel or axle of the railway rolling stock. The braking system also comprises a friction assembly which comprises a shoe carrier which supports a friction shoe. The friction shoe usually comprises means for attaching to the shoe carrier and a friction pad. When a driver activates the braking system, the friction pad of the friction shoe comes into contact with the disc to exert a braking force on the disc. Thus, by friction, the friction shoe brakes the disc secured to the wheel or axle. Generally, railway rolling stock comprises two friction assemblies, arranged on either side of the disc so as to grip, or in other words sandwich, the disc to compress it on both sides.The friction pad of the friction shoe usually consists of a metallic material, such as cast iron, sintered material, or a composite material. Thus, when the friction pad of the friction shoe rubs against the disc, particles of matter from the friction pad and the disc are emitted into the ambient atmosphere around the friction assembly. Thus, the braking system emits atmospheric pollution in the form of more or less fine particles.

[0003] We therefore sought to capture the particles of matter emitted during braking, in particular by placing a suction device, powered by a pump, near an emission zone of the particles from the rubbing pad of the friction sole. In addition, we sought to make this suction of particles as efficient as possible.

[0004] One solution to this problem is the friction assembly shown in figures 17 And 18, which represents the prior art. This prior art is described in document FR 3088394. The figure 17 is a bottom view of this set, and the figure 18 is a cross-section along line XVIII-XVIII of the figure 17 .

[0005] The sole holder 103 extends longitudinally in a longitudinal direction X, and transversely in a transverse direction Y. The XY plane is horizontal. The Z direction, perpendicular to the XY plane to form a reference frame (X,Y,Z), is vertical, oriented upwards. The sole holder 103 comprises a lower face 131 intended to accommodate a friction sole 102, and an upper face 132, which each extend parallel to the XY plane.

[0006] The sole holder 103 has on its lower face 131 a concave dovetailed receiving slide 105, which extends longitudinally from a first end of the sole holder 103 to near the second end of the sole holder 103 where this slide is non-emerging. The sole holder 103 comprises on the longitudinal axis X two spaced secondary conduits 138. Each secondary conduit 138 connects the upper face 132 to the bottom of the slide 105 on the upper face.

[0007] The friction sole 102 is in two identical parts, where each part has a friction face 121 intended to be in frictional contact with the disc (not shown) of the vehicle and an opposite face 122. This opposite face 122 has a convex dovetail profile 104 configured to cooperate with the receiving slide 105. In use, a first part of the sole 102 is pushed along the longitudinal axis X by sliding the profile 104 in the slide 105, until it stops against the slide 105. Then the second part of the sole 102 is pushed along the longitudinal axis X by sliding the profile 104 in the slide 105, until it stops against the first part of the sole 102, the contact surfaces of the first part and the second part being ideally shaped to fit together over their entire surface.

[0008] Each of the parts of the sole 102 comprises a primary duct 128 oriented along the vertical axis Z. When these parts are fixed to the sole holder 103 in use, each of the two primary ducts 128 is located opposite a secondary duct 138. The axis B designates the main axis of a primary duct 128 and of the secondary duct 138 located opposite, this primary duct 128 and this secondary duct 138 therefore being coaxial. Thus, each primary duct 128 forms, with one of the secondary ducts 138 arranged in the sole holder 103, a circuit which makes it possible to suck up particles emitted by the friction sole 102 during braking. The axis B is therefore parallel to the vertical axis Z.

[0009] A connecting ring 108, consisting of a tube and a collar 1082 extending this tube radially and outwards at one of its ends, is mounted in the secondary conduit 138. The tube is inserted into the secondary conduit 138, the external diameter of the tube being equal to the internal diameter of the secondary conduit 138 in order to ensure the best possible seal. The collar 1082 is housed in an annular housing of the sole plate holder 103, this housing being centered on the main axis B and opposite the opposite face 122 of the sole plate 102. The annular housing has a diameter greater than that of the secondary conduit 138 and less than that of the collar 1082. Thus, the collar 1082 is sandwiched between the profile of the sole plate 102 and the bottom of the slide 105 of the sole plate holder 103. Once in its housing, the collar 1082 is in contact with the face 122 of the profile 104 of the sole plate 102.This contact is achieved for example by deformation (crushing) of the collar 1082 between the bottom of the housing and the face 122. Alternatively (as shown in . figure 18 , this contact is made by compression of a helical spring mounted on the tube between the collar 1082 and the bottom of the housing. Thus, the collar 1082 itself, or the helical spring, is a return mechanism 190 which makes it possible to press the collar 1082 against the profile 104 (see below).

[0010] The connecting ring 108 passes entirely through the sole holder 103 and extends beyond it on its upper face 132 to its lower face 131 provided with the slide 105. On this end of the tube of the ring 108 is fixed a pipe 150 which is connected to a suction device (not shown) and which allows the suction through the primary conduit 128 and the secondary conduit 138 of the particles resulting from the braking of the railway vehicle by wear of the sole 102. The pipe 150 and the suction device constitute a device for evacuating the particles.

[0011] The connecting ring 108 serves to guide the particles resulting from braking from the primary duct 128 of the sole 102 to the secondary duct 138 of the sole holder 103. The connecting ring 108 therefore aims to prevent possible leaks through the primary duct 128 and the secondary duct 138. In particular, the connecting ring 108 aims to limit the quantity of particles resulting from braking which could slip into the gap at the interface between the friction sole 102 and the sole holder 103, and above all to prevent a flow of air from the outside from penetrating through this gap into the secondary duct 138, which would degrade the suction by the suction device.

[0012] In addition, the connecting ring 108 is pressed against the profile 104 using a return mechanism 190, as indicated above. This return mechanism 190 effectively prevents air from passing through the interface between the sole 102 and the sole holder 103 at the primary duct 128 and the secondary duct 138, this air from passing through being due to clearances at the interface between the sole holder 103 and the sole 102.

[0013] The ring 108 must be locked in translation in both directions along the axis B, in order to be secured to the sole plate holder 103. This locking is achieved in one direction by the collar 1082 at the lower end of the ring 108. This locking is achieved in the other direction by fixing the upper end of the ring 108 to the pipe 150 which is connected to the suction device. The ring 108 is in two parts. After fixing the upper part of the ring 108 to the pipe 150, and inserting the lower part of the ring 108 into the secondary conduit 138, the upper part and the lower part of the ring are secured, for example by screwing, by welding, or by any other suitable means.

[0014] However, this bidirectional translational blocking requires access to both ends of the ring 108. However, in certain configurations, the suction device, which is for example a pneumatic block, is an integral part of the sole plate holder 103.

[0015] Thus, there is a friction assembly for a brake system for railway rolling stock, the friction assembly comprising on the one hand a shoe holder comprising a lower face, and an upper face, and on the other hand at least one sole made of friction material comprising a first face which is the friction face, and a second face which is capable of being fixed on the lower face by a fixing mechanism, the sole comprising at least one primary duct connecting the first face and the second face, the shoe holder comprising at least one secondary duct of central axis B, the at least one primary duct being capable of being aligned with one of the at least one secondary duct, and at least one joining ring arranged in the secondary duct and establishing a junction with the primary duct, the friction assembly further comprising a block connected to a suction device, this block being an integral part of the shoe holder at the upper face.

[0016] In this configuration, one end of the ring 108 (upper end, on the suction device side) is not accessible. Mounting the ring 108 on the sole plate holder 103 is then not possible. Description de l'invention

[0017] The present invention aims to remedy these drawbacks.

[0018] The invention aims to propose a friction assembly for a railway brake system in which the block which is connected to a suction system, for example a pneumatic block, is an integral part of the shoe holder, which allows mounting on the shoe holder of a connecting ring which allows evacuation of the particles emitted by wear of the shoe towards the suction device.

[0019] This aim is achieved by the fact that the block has a cavity and at least one hole which connects the cavity and the upper face and which is aligned with the at least one secondary conduit and in which the connecting ring is able to slide, the cavity being connected by a circuit to the suction device, and in that it comprises a mechanism for securing the at least one connecting ring with the block when the at least one connecting ring is arranged in the at least one hole and in the at least one secondary conduit.

[0020] Thanks to these provisions, each connecting ring is able to be inserted into the hole and into the secondary conduit so as to connect the sole with the suction device. The connecting ring is then secured to the block by the securing mechanism. Thus, the ring is kept secured to the sole holder so that during operation the evacuation of particles coming from the sole to the suction device is carried out reliably.

[0021] For example, the at least one joining ring includes a body and a flange at a first end of the body, the distal end of the body carrying tabs that extend radially outwardly into the cavity, and wherein the securing mechanism includes the flange, the tabs, and the inner edge of the at least one hole in the cavity.

[0022] Thus, the joining ring(s) with the block is secured by a simple snap-fastening.

[0023] For example, the at least one joining ring comprises a body and a flange at a first end of the body, the distal end of the body carrying tabs that are plastically deformed radially outwardly into the cavity, and wherein the securing mechanism comprises the flange, the tabs and the inner edge of the at least one hole of the cavity.

[0024] Thus, the separation of the joining ring(s) from the block, thanks to the plastic deformation of the tabs, is less easy.

[0025] For example, the at least one joining ring comprises a body and a flange at a first end of the body, the distal end of the body carrying at least one protrusion which extends radially outwardly into the cavity, in which the at least one hole carries at least one groove in which the at least one protrusion is capable of sliding, in which the inner edge of the at least one hole of the cavity comprises a housing capable of receiving the protrusion and in which the securing mechanism comprises the flange, the protrusion and the housing.

[0026] Thus, the joining ring(s) with the block is secured by a bayonet movement of the ring, and is removable by performing the reverse movement.

[0027] For example, the friction assembly further comprises a return mechanism which is capable of pressing the ring against the second face.

[0028] This improves the seal between the connecting rings and the sole, along the path of evacuation of particles released by the sole.

[0029] For example, the attachment mechanism includes a docking slide that is formed on the underside, and a profile that is formed on the second side and is configured to cooperate with the docking slide.

[0030] This makes it easier to attach the sole to the sole holder, as it is done by sliding, and is also removable.

[0031] The invention also relates to a method for securing a connecting ring mounted on a sole holder with a block connected to a suction device, the sole holder comprising a lower face, an upper face, and at least one secondary conduit (38) of central axis A, the block forming an integral part of the sole holder at the upper face, the sole holder and the connecting ring forming part of a friction assembly for a brake system for railway rolling stock, the friction assembly further comprising a sole made of friction material comprising a first face which is the friction face, a second face which is capable of being fixed on the lower face by a fixing mechanism, and at least one primary conduit which connects the first face and the second face,the at least one junction ring being arranged in the at least one secondary conduit and establishing a junction with the at least one primary conduit when the at least one primary conduit is aligned with one of the at least one secondary conduit.,

[0032] According to the invention, the method comprises the following steps: (a) The block is provided with a cavity which is connected by a circuit to the suction device, with at least one hole which connects the cavity and the upper face and which is aligned with the at least one secondary conduit and in which the at least one connecting ring is capable of sliding; (b) The at least one connecting ring is arranged in the at least one hole and in the at least one secondary conduit by sliding along the axis A from the lower face; (c) The at least one connecting ring is secured to the block by means of a securing mechanism; (d) The sole is assembled on the sole holder until the sole covers the at least one connecting ring.

[0033] For example, the at least one joining ring comprises a body and a collar at a first end of the body, the distal end of the body carrying tabs which extend radially outwards in their rest position, such that, in step (b), the tabs move towards each other elastically when the body slides in said at least one hole and in said at least one secondary conduit, and such that, in step (c), the tabs return to their rest positions and are able to bear against the internal edge of the at least one hole of the cavity, the securing mechanism comprising the collar, the tabs and the internal edge of the at least one hole.

[0034] For example, the at least one joining ring comprises a body and a collar at a first end of the body, the distal end of the body carrying tabs which extend substantially in the extension of the body in their rest positions, such that, in step (b), the body slides freely in the at least one hole and in the at least one secondary conduit, and such that, in step (c), the tabs are crushed against the bottom of the cavity such that the tabs are plastically deformed radially outwards and are able to bear against the edge of the at least one hole of the cavity, the securing mechanism comprising the collar, the tabs and the internal edge of the at least one hole.

[0035] For example, the at least one joining ring comprises a body and a collar at a first end of the body, the distal end of the body carrying at least one protuberance which extends radially outwards, and the at least one hole carrying at least one groove in which the at least one protuberance is capable of sliding, and the internal edge of the at least one hole of the cavity comprising a housing capable of receiving the at least one protuberance such that, in step (b), the body slides freely in the at least one hole and in the at least one secondary conduit until the distal end of the body emerges in the cavity, and such that, in step (c), the ring is pivoted around the main axis A until one of said at least one protuberance is located opposite the housing, then the ring is slid in the opposite direction until one of the at least one protuberance is housed in the housing and bears against the bottom of the housing,the securing mechanism comprising the collar, the protrusion and the housing.,

[0036] The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of embodiments shown as non-limiting examples. The description refers to the appended drawings in which: [ Fig. 1 ] There figure 1 is a perspective view and longitudinal section in the plane (X, Z) of a friction assembly according to a first embodiment of the invention, with the sole assembled with the sole holder; [ Fig. 2 ] There figure 2 is a sectional view in the plane (X, Z) of the region of the friction assembly which includes the block, according to a first embodiment of the invention, before the rings are secured to the block. Fig. 3 ] There figure 3 is a sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a first embodiment of the invention, at a later stage of the step of the figure 2 . [ Fig. 4 ] There figure 4 is a sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a first embodiment of the invention, at a later stage of the step of the figure 3 . [ Fig. 5 ] There figure 5 is a sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a first embodiment of the invention, after the rings have been secured to the block. Fig. 6 ] There figure 6 is a sectional view in the (X, Z) plane of a portion of the friction assembly 1 illustrated in figure 1 . [ Fig. 7 ] There figure 7 is a sectional view in the plane (X, Z) of the region of the friction assembly which includes the block, according to a first embodiment of the invention, which shows the separation of the rings from the block. Fig. 8 ] There figure 8 is a sectional view in the plane (X, Z) of the region of the friction assembly which includes the block, according to a second embodiment of the invention, before the rings are secured to the block. Fig. 9 ] There figure 9 is a sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a second embodiment of the invention, at a later stage of the step of the figure 8 . [ Fig. 10 ] There figure 10 is a sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a second embodiment of the invention, at a later stage of the step of the figure 9 . [ Fig. 11 ] There figure 11 is a sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a second embodiment of the invention, after the rings have been secured to the block. Fig. 12 ] There figure 12 is a sectional view in the plane (X, Z) of the region of the friction assembly which includes the block, according to a second embodiment of the invention, which shows the separation of the rings from the block. Fig. 13 ] There figure 13 is a perspective view and partial section in the plane (X, Z) of the region of the friction assembly which includes the block, according to a third embodiment of the invention, before the rings are secured to the block. Fig. 14 ] There figure 14 is a perspective and partial sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a third embodiment of the invention, at a later stage of the step of the figure 13 . [ Fig. 15 ] There figure 15 is a perspective and partial sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a third embodiment of the invention, at a later stage of the step of the figure 14 . [ Fig. 16 ] There figure 16 is a perspective and partial sectional view in the plane (X, Z) of the region of the friction assembly which comprises the block, according to a third embodiment of the invention, after the rings have been secured to the block. Fig. 17 ] There figure 17 , already described, is a bottom view of a friction assembly according to the prior art; [ Fig. 18 ] There figure 18 , already described, is a cross-section along line XVIII-XVIII of the figure 17 . Description détaillée de l'invention

[0037] There figure 1 illustrates a friction assembly 1 for a brake system for railway rolling stock. For example, these brakes are disc brakes. For example, these brakes are brakes on a tread of the wheel of the rolling stock. The assembly extends longitudinally along a longitudinal axis X, and vertically along a vertical axis Z. The transverse axis Y forms a trigonometric reference frame with the axes X and Z. The friction assembly 1 is shown in perspective. For the sake of clarity, the assembly is shown in section in the vertical plane (X, Z), that is to say in the plane which passes through the central axes A of the secondary ducts 38.

[0038] The friction assembly 1 comprises on the one hand a sole holder 3, and on the other hand at least one sole 2 made of friction material. The sole holder 3 has a lower face 31, and an upper face 32. The sole 2 has a first face 21 which is the friction face, and a second face 22. In operation, the sole 2 is secured to the sole holder 3 by a fixing mechanism (4, 5). For example, this fixing mechanism comprises a receiving slide 5 which is formed on the lower face 31, and a profile 4 which is formed on the second face 22 and which is configured to cooperate with the receiving slide 5. Thus, the securing of the sole 2 to the sole holder 3 is achieved by insertion and translation of the profile 4 in the slide 5 along the longitudinal axis X. The fixing mechanism is then such that this securing is removable.Generally speaking, the connection of the sole 2 with the sole holder 3 is removable, which allows replacement of the sole 2 once worn.

[0039] The sole 2 comprises at least one primary conduit 28 sealingly connecting the first face 21 and the second face 22. figure 1 , the sole 2 comprises two primary conduits 28. The sole holder 3 comprises at least one secondary conduit 38 with central axis A which sealably connects the upper face 32 and the lower face 31 at the bottom of the receiving slide 5. In figure 1 , the sole plate holder 3 comprises two secondary conduits 38. The sole plate holder 3 comprises at least one junction ring 8 arranged in the at least one secondary conduit 38 and establishing a junction with the at least one primary conduit 28. In figure 1 , the sole plate holder 3 comprises two connecting rings 8. When the sole plate 2 is secured to the sole plate holder 3, each primary conduit 28 is aligned with a secondary conduit 38, that is to say that the central axis of each primary conduit 28 is the central axis A of the secondary conduit 38 with which it is aligned.

[0040] A connecting ring 8 comprises a tubular body 81 and a collar 82 at one end of this body 81. The collar 82 extends radially outwards from the body 81, and therefore has a diameter greater than the external diameter of the body 81. For example, the internal diameter of the body 81 is greater than the diameter of a primary conduit 28 in order to compensate for the clearances between the sole 2 and the sole holder 3 along the X axis. The distal end of the body 81 is therefore located opposite the collar 82.

[0041] In the description below, the plural article "des" is used before the elements "primary conduits 28", "secondary conduits 38", "junction rings 8", "holes 58", and the determinant "each", to deal with the cases of two or more of these elements. The description below is also valid in the case of a single primary conduit 28, a single secondary conduit 38, a single junction ring 8 and a single hole 58.

[0042] The friction assembly 1 further comprises a block 50 which is an integral part of the sole plate holder 3 at the upper face 32. For example, this block 50 is a pneumatic block. By “being an integral part”, it is meant that the block 50 is not separable from the sole plate holder 3, except with tools. For example, the block 50 is molded with the sole plate holder 3, or is welded with the sole plate holder 3. The block 50 covers the upper face 32 of the sole plate holder 3 at the portion of the upper face 32 which comprises the orifices of the secondary conduits 38. The block 50 comprises a cavity 55 which is connected to a circuit 51 which is connected to a suction device. The block 50 comprises holes 58 which connect the cavity 55 and the upper face 32, each of the holes 58 being located opposite one of the secondary conduits 38. As illustrated in figure 1 , the block 50 therefore has two holes 58. The block 50 being an integral part of the sole plate holder 3, a ring 8 cannot be inserted into a secondary conduit 38 via the upper face 32.

[0043] Each ring 8 can be inserted into a secondary conduit 38 only via the lower face 31, before securing the sole 2 with the sole holder 3. Thus, the body 81 of a ring 8 is inserted into a secondary conduit 38, the collar 82 being located on the side of the lower face 31. The diameter of the collar 82 is equal to or slightly less than the diameter of the secondary conduit 38. The diameter of each of the holes 58 is equal to or slightly greater than the external diameter of the body 81, and less than the diameter of the collar 82. Thus, when the ring 8 is inserted into the secondary conduit 38, the collar 82 abuts against the edge of the hole 58 which is located opposite the secondary conduit 38, either directly or indirectly, as explained below.

[0044] In the case of indirect contact, a spring (for example a helical spring) is mounted on the body 81 between the collar 82 and the edge of the hole 58. At rest, the spring is in contact with the collar 82 and the edge of the hole 58, and the collar 82 protrudes from the lower face 31 (for example at the bottom of the slide 5 if this slide 5 is present). When the sole 2 is secured to the sole holder 3 (for example by sliding the profile 4 of the sole 2 in the slide 5) the second face 22 is in contact with the lower face 31, the collar 82 is pushed back into the secondary duct 38 and compresses the spring. This solution is shown in figure 1 .

[0045] In the case of direct contact between the collar 82 and the edge of the hole 58, the collar 82 is shaped such that, undeformed, it protrudes from the lower face 31. When the sole 2 is secured to the sole holder 3, the collar 82 is deformed between the second face 22 and the edge of the hole 58. This deformation is for example a compression along the axis A of the material of the collar. Alternatively, the collar 82 has a convex or concave shape at rest, and this deformation is a flattening of the collar 82. In all cases of direct contact, the deformation of the collar 82 also fulfills a sealing function between the ring 8 and the second face 22.

[0046] In both cases of contact (direct or indirect), the collar 82 is held in contact against the second face 22 of the sole 2. This holding is achieved either by deformation of the collar 82 itself, or by compression of the spring, which therefore each constitute a return mechanism 90 which makes it possible to press the collar 82 against the second face 22. Other return mechanisms 90 fulfilling the same function can be used.

[0047] The collar 82 therefore provides a translational blocking of the ring 8 in the secondary conduit 38 along the axis A in one direction, namely the upward direction in the figures (movement of the ring 8 upwards).

[0048] The friction assembly 1 comprises a securing mechanism 70 for securing the connecting rings 8 with the block 50 when each of the connecting rings 8 is arranged in a hole 58 and in a secondary conduit 38. Thus, when a connecting ring 8 is pushed upwards into the hole 58 until its distal end opens into the cavity 55, this securing mechanism 70 prevents the connecting ring 8 from translating in the opposite direction, i.e. downwards. The connecting ring 8 is therefore blocked in the position of securing with the block 50 and cannot come out of the hole 58.

[0049] We will now describe different embodiments of this securing mechanism 70 and of the method of securing each joining ring 8 with the block 50.

[0050] In each of the embodiments of this method, the first step (step (a)) consists of providing the block 50 with a cavity 55, with one or more holes 58 connecting this cavity 55 and the upper face 32 and each located opposite a secondary conduit 38 of the sole plate holder 30 and in which a ring 8 is able to slide, and with a circuit 51 which connects this cavity 55 to the suction device.

[0051] According to a first embodiment, illustrated in figures 1 à 7 , the distal end of the body 81 carries tabs 85 which, at rest, extend radially outwards. For example, the tabs 85 are molded. For example, the tabs 85 may be machined and shaped by bending. The figures 2 à 5 And 7 are sectional views in the (X, Z) plane of the region of the friction assembly 1 which includes the block 50. For the sake of clarity, the sole 2 is not shown in the figures 2 à 5 And 7 .

[0052] Thus, the securing mechanism 70 comprises the collar 82, the tabs 85 and the internal edge of the hole 58 of the cavity 55. The term "internal edge" refers to the edge of a hole 58 which is located inside the cavity 55. The operation of the securing mechanism is explained below.

[0053] In each hole 58, and in each secondary conduit 38 aligned with this hole 58, a joining ring 8 is inserted by sliding along the axis A of this hole 58. This insertion is carried out from the lower face 31 of the sole plate holder, upwards in the figures, and constitutes the second step (step (b)).

[0054] There figure 2 illustrates the situation where the joining rings 8 are inserted into the secondary conduits 38 and begin to be inserted into the holes 58. The distal ends of the tabs 85 are in contact with the external edge of the holes 58. The term "external edge" refers to the edge of a hole 58 which is located outside the block 50, i.e. opposite the secondary conduit 38.

[0055] There figure 3 illustrates the situation where the connecting rings 8 are inserted into the holes 58. When entering a hole 58, the ends of the tabs 85 are pushed radially towards the longitudinal central axis of the connecting ring 8 by the side wall 585 of the hole 58. This deformation of the tabs 85 is within their elastic deformation range. Advantageously, the outer edge of each hole 58 is flared towards the outside of the hole 58 so as to help the tabs 85 to be pushed radially towards the central axis of the connecting ring. During the translation of the connecting ring 8 in the hole 58, the tabs 85 slide along this side wall 585 from the outer edge to the inner edge of the hole 58.

[0056] There figure 4 illustrates the situation where the distal end of each joining ring 8 emerges into the cavity 55. Thanks to their elasticity, the tabs 85 then deform radially outwards to return to their initial position (rest position).

[0057] There figure 5 illustrates the situation where each of the joining rings 8 is lowered until the distal ends of the tabs 85 come into contact with the internal edge of a hole 58. These distal ends being curved radially outwards, they press on the internal edge and prevent the joining rings 8 from coming out of the holes 58 (step (c), third step). The tabs 85 and the internal edge of the hole 58 are therefore part of the securing mechanism 70.

[0058] Advantageously, the friction assembly 1 comprises a return mechanism 90 (in the case illustrated in the figures this mechanism is a spring around the connecting ring 8 which is located between the collar 82 and the external edge of the hole 58. For example this spring is helical). When the distal end of a connecting ring 8 emerges in the cavity 55, this return mechanism 90 is activated (the spring is compressed) so that it tends to bring the connecting ring 8 out of the hole 58, that is to say to push the connecting ring 8 downwards, as illustrated in figure 5 The collar 82 of each joining ring 8 then emerges partly at the level of the lower face 31 of the sole plate holder 3.

[0059] In a fourth step (step (d)), the sole 2 is assembled on the sole holder 3 until the sole 2 covers each of the joining rings 8. This situation is illustrated in figure 6 , in the case where the sole has two halves. The figure 6 is a sectional view in the (X, Z) plane of a portion of the friction assembly 1 illustrated in figure 1 . On the right side of the figure 6 , the right half of the sole 2 is pressed against the sole holder 3 in such a way that the second face 22 of this right half is in contact with the lower face 31 of the sole holder 3. On the left part of the figure 6 , there is a clearance between the left half of the sole 2 and the sole holder 3 such that the second face 22 of this left half is not in contact with the lower face 31 of the sole holder 3. In all cases, the return mechanism 90 presses the joining ring 8 against the second face 22 of the sole 2, and the distal ends of the joining rings 8 are in the cavity 55.

[0060] There figure 7 illustrates a method for separating a connecting ring 8 from the block 50. A threaded rod 201 is screwed into the hole of the connecting ring 8 along its longitudinal axis so that the connecting ring 8 is in helical connection with the rod 201 over its entire length. Then the collar 82 of the connecting ring 8 is gripped with pliers 202 in order to lock it in rotation. By screwing the rod 201 into abutment against the ceiling of the cavity 55, the connecting ring 8 translates downwards thanks to the thread of the rod 201. By translating downwards along the rod 201, the tabs 85 are elastically deformed and forced between the rod 201 and the side wall 585 of the hole 58 until they emerge in the secondary conduit 38. The connecting ring 8 can then be freely removed from the block 50 and the sole plate holder 3.

[0061] A second embodiment is now described, illustrated in figures 8 à 12 , in which the distal end of the body 81 carries tabs 85 which extend substantially in the extension of the body 81 in their rest positions and which are capable of being plastically deformed radially outwards. figures 8 à 12 are sectional views in the (X, Z) plane of the region of the friction assembly 1 which includes the block 50. For the sake of clarity, the sole 2 is not shown in these figures.

[0062] Thus, the securing mechanism 70 comprises the collar 82, the tabs 85 and the internal edge of the hole 58 of the cavity 55. The operation of the securing mechanism is explained below.

[0063] In each hole 58, and in each secondary conduit 38 aligned with this hole 58, a joining ring 8 is inserted by sliding along the axis A of this hole 58. This insertion is carried out from the lower face 31 of the sole plate holder, upwards in the figures, and constitutes the second step (step (b)).

[0064] There figure 8 illustrates the situation where the joining rings 8 are inserted into the secondary conduits 38 and before they begin to be inserted into the holes 58.

[0065] There figure 9 illustrates the situation where the joining rings 8 are inserted into the holes 58. After having penetrated into a hole 58, the tabs 85 and the body 81 slide freely along the side wall 585 of the hole 58 from the external edge to the internal edge of the hole 58. In fact, the tabs 85 extend substantially in the extension of the body 81.

[0066] The ceiling of the cavity 55 is provided, opposite each hole 58, with a conical protrusion 59 in the shape of a cone, or a truncated cone. The axis of symmetry of this protrusion 59 is therefore aligned with the axis A of the hole 58. The base of this protrusion 59 is located at the level of this ceiling and its distal end is directed towards the hole 58 which is in the floor of the cavity 55. After the distal end of each connecting ring 8 emerges in the cavity 55, each ring 8 continues to slide upwards until the tabs 58 come into contact with the side wall of the conical protrusion 59. When each ring 8 continues to slide further upwards, the tabs 85 deform radially outwards. This deformation takes place in the elastic domain of the tabs 85 then in their plastic domain, such that the deformation of the tabs 85 from their initial rectilinear position is permanent.After this plastic deformation, the tabs 85 are in a new resting state in which their distal ends are curved radially outwards. The . figure 10 illustrates this plastic deformation of the tabs 85.

[0067] There figure 11 illustrates the situation where each of the joining rings 8 is lowered until the distal ends of the tabs 85 come into contact with the internal edge of a hole 58. These distal ends being curved radially outwards, they press on the internal edge and prevent the joining rings 8 from coming out of the holes 58 (step (c), third step). The tabs 85 and the internal edge of the hole 58 are therefore part of the securing mechanism 70.

[0068] Advantageously, the friction assembly 1 comprises a return mechanism 90 (in the case illustrated in the figures this mechanism is a spring around the connecting ring 8 which is located between the collar 82 and the external edge of the hole 58. For example this spring is helical). When the distal end of a connecting ring 8 emerges in the cavity 55, this return mechanism 90 is activated (the spring is compressed) so that it tends to bring the connecting ring 8 out of the hole 58, that is to say to push the connecting ring 8 downwards, as illustrated in figure 11 The collar 82 of each joining ring 8 then emerges partly at the level of the lower face 31 of the sole plate holder 3.

[0069] In a fourth step (step (d)), the sole 2 is assembled on the sole holder 3 until the sole 2 covers each of the joining rings 8. This situation is similar to that illustrated in figure 6 in the case of the first embodiment. The return mechanism 90 presses the joining ring 8 against the second face 22 of the sole 2, and the distal ends 85 of the joining rings 8 are in the cavity 55.

[0070] Advantageously, in the first and in the second embodiment, the side wall 585 of each hole 58 comprises an O-ring 587 which is housed in an annular cavity of this side wall 585. This O-ring 587 makes it possible to improve the sealing between the joining ring 8 and the block 50.

[0071] There figure 12 illustrates a method for separating a connecting ring 8 from the block 50. A threaded rod 201 is screwed into the hole of the connecting ring 8 along its longitudinal axis so that the connecting ring 8 is in helical connection with the rod 201 over its entire length. Then the collar 82 of the connecting ring 8 is gripped with pliers 202 in order to lock it in rotation. By screwing the rod 201 into abutment against the ceiling of the cavity 55, the connecting ring 8 translates downwards thanks to the thread of the rod 201. By translating downwards along the rod 201, the tabs 85 are plastically deformed and forced between the rod 201 and the side wall 585 of the hole 58 until they emerge in the secondary conduit 38. The connecting ring 8 can then be freely removed from the block 50 and the sole plate holder 3.

[0072] A third embodiment is now described, illustrated in figures 13 à 16 , wherein the distal end of the body 81 of each joining ring 8 carries two diametrically opposed protrusions 86 which extend radially outwards. Each hole 58 carries two diametrically opposed grooves 581 which extend longitudinally along its side wall 585 from the inner edge to the outer edge of the hole 58, such that each of the protrusions 86 is able to slide in one of the grooves 581 when the connecting ring 8 slides in the hole 58. The edge of each hole 58 comprises a housing 586 which is able to receive one of the protrusions 86. This housing 586 extends radially from the inner edge of the hole 58 and is bordered by a side wall 5861 which extends along the main axis A. The housing 586 comprises a bottom 5862 which extends parallel to the floor of the cavity 55. The housing 586 is open along the main axis A towards the ceiling of the cavity 55 and is open radially towards the hole 58. figures 13 à 16 are perspective and partial sectional views in the plane (X, Z) of the region of the friction assembly 1 which includes the block 50. For the sake of clarity, in each of these figures the two connecting rings 8 are shown whole, and for one of the connecting rings 8 the sectional plane is translated along the transverse axis Y so as to show the entire secondary conduit 38 and the hole 58 around this connecting ring 8. Furthermore the sole 2 is not shown.

[0073] In the general case, the distal end of the body 81 of each connecting ring 8 can carry a protuberance 86 or more than two protuberances 86. Each hole 58 carries as many grooves 581 as protuberances 86, these grooves 581 being arranged such that each of the protuberances 86 slides in one of the grooves 581 when the connecting ring 8 slides in the hole 58.

[0074] Thus, the securing mechanism 70 comprises the collar 82, the protrusion(s) 86 and the housing 586. The operation of the securing mechanism is explained below.

[0075] In each hole 58, and in each secondary conduit 38 aligned with this hole 58, a joining ring 8 is inserted by sliding along the axis A of this hole 58. This insertion is carried out from the lower face 31 of the sole plate holder, upwards in the figures, and constitutes the second step (step (b)).

[0076] There figure 13 illustrates the situation where the joining rings 8 are inserted into the secondary conduits 38 and before they begin to be inserted into the holes 58.

[0077] There figure 14 illustrates the situation where the joining rings 8 are inserted into the holes 58. When entering a hole 58, the protrusions 86 slide freely in the grooves 581 from the outer edge to the inner edge of the hole 58.

[0078] There figure 15 illustrates the situation where the protrusions 86 of each joining ring 8 emerge into the cavity 55.

[0079] Each connecting ring 8 is pushed into the hole 58 and pivoted about its main (longitudinal) axis until one of the protrusions 86 is located above the housing 586. Then each connecting ring 8 is lowered again until this protrusion 86 is housed in the housing 586 until it comes into contact with the bottom 5862 (step (c), third step).

[0080] Advantageously, the friction assembly 1 comprises a return mechanism 90 (in the case illustrated in the figures this mechanism is a spring around the connecting ring 8 which is located between the collar 82 and the external edge of the hole 58. For example this spring is helical). When the distal end of a connecting ring 8 emerges in the cavity 55, this return mechanism 90 is activated (the spring is compressed) so that it tends to bring the connecting ring 8 out of the hole 58. Thus, the return mechanism 90 pushes the connecting ring 8 downwards and holds the protuberance 86 in the housing 586 so as to secure the connecting ring 8 with the block 50, as illustrated in figure 16 The collar 82 of each joining ring 8 then emerges partly at the level of the lower face 31 of the sole plate holder 3.

[0081] In a fourth step (step (d)), the sole 2 is assembled on the sole holder 3 until the sole 2 covers each of the joining rings 8. This situation is similar to that illustrated in figure 6 in the case of the first embodiment. The return mechanism 90 presses the junction ring 8 against the second face 22 of the sole 2, and the protrusions 86 of the junction rings 8 are in the cavity 55.

[0082] To separate a connecting ring 8 from the block 50, it is slid upwards to remove the protrusion 86 from the housing 586. Then the connecting ring 8 is pivoted around its main axis until the protrusions 86 are aligned with the grooves 581. Then the connecting ring 8 is pulled downwards so that the protrusions 86 slide in the grooves 581. The connecting ring 8 is then freely removed from the block 50 and from the sole plate holder 3.

[0083] As described above, the method for securing a connecting ring 8 to a block 50, connected to a suction device, is as follows: In the method according to the invention, the sole holder 3 comprises a lower face 31, an upper face 32, and at least one secondary conduit 38 with a central axis A, the block 50 is an integral part of the sole holder 3 at the upper face 32, the sole holder 3 and the connecting ring 8 are part of a friction assembly 1 for a railway disc brake system for railway rolling stock which further comprises a sole 2 made of friction material comprising a first face 21 which is the friction face, a second face 22 which is capable of being fixed to the lower face 31 by a fixing mechanism 4, 5, and at least one primary conduit 28 which connects the first face 21 and the second face 22,the at least one junction ring 8 being arranged in the at least one secondary conduit 38 and establishing a junction with the at least one primary conduit 28 when the at least one primary conduit 28 is aligned with one of the at least one secondary conduit 38. This method comprises the following steps: , (a) The block 50 is provided with a cavity 55 which is connected by a circuit 51 to the suction device, with at least one hole 58 which connects the cavity 55 and the upper face 32 and which is aligned with the at least one secondary conduit 38 and in which the at least one connecting ring 8 is capable of sliding; (b) The at least one connecting ring 8 is arranged in the at least one hole 58 and in the at least one secondary conduit 38 by sliding along the axis A from the lower face 31; (c) The at least one connecting ring 8 is secured to the block 50 by means of a securing mechanism 70; (d) The sole 2 is assembled on the sole holder 3 until the sole 2 covers the at least one connecting ring 8.

[0084] According to a first embodiment, the at least one connecting ring 8 comprises a body 81 and a collar 82 at a first end of the body 81, the distal end of the body 81 carries tabs 85 which extend radially outwards in their rest positions, such that, in step (b), the tabs 85 move towards each other elastically when the body 81 slides in the at least one hole 58 and in the at least one secondary conduit 38, and, in step (c), the tabs 85 return to their rest positions and are able to bear against the internal edge of the at least one hole 58 of the cavity 55. The securing mechanism 70 comprises the collar 82, the tabs 85 and said internal edge of the at least one hole 58.

[0085] According to a second embodiment, the at least one connecting ring 8 comprises a body 81 and a collar 82 at a first end of the body 81, the distal end of the body 81 carries tabs 85 which extend substantially in the extension of the body 81 in their rest positions, such that, in step (b), the body 81 slides freely in the at least one hole 58 and in the at least one secondary conduit 38, and, in step (c), the tabs 85 are crushed against the bottom of the cavity such that the tabs are plastically deformed radially outwards and are able to bear against the edge of the at least one hole 58 of the cavity 55. The securing mechanism 70 comprises the collar 82, the tabs 85 and said internal edge of the at least one hole 58.

[0086] According to a third embodiment, the at least one joining ring 8 comprises a body 81 and a collar 82 at a first end of the body 81, the distal end of the body 81 carries at least one protuberance 86 which extends radially outwards, and the at least one hole 58 carries at least one groove 581 in which the at least one protuberance 86 is capable of sliding, and the internal edge of the at least one hole 58 comprises a housing 586 capable of receiving the at least one protuberance 86 such that, in step (b), the body 81 slides freely in the at least one hole 58 and in the at least one secondary conduit 38 until the distal end of the body 81 emerges in said cavity 55, and such that, in step (c), the ring 8 is pivoted around the main axis A until one of the at least one protuberance 86 is located opposite accommodation 586,then the ring 8 is slid in the opposite direction until one of the protrusions 86 is housed in the housing 586 and bears against the bottom of the housing 586. The securing mechanism 70 comprises the collar 82, the at least one protrusion 86 and the housing 586.,

Claims

1. Friction assembly (1) for a braking system for railway rolling stock, said friction assembly (1) comprising a brake head (3) comprising a lower face (31), an upper face (32), and at least one secondary channel (38) of central axis A which connects said lower face (31) and an upper face (32); the break head (3) further comprising at least one plate (2) made of friction material comprising a first face (21) which is the friction face, a second face (22) which is adapted to be fixed on said lower face (31) by a fixing mechanism (4, 5), and at least one primary channel (28) which connects said first face (21) and said second face (22); and furthermore at least one connecting ring (8) which is arranged in said at least one secondary channel (38) and which establishes a connection with said at least one primary channel (28) when said at least one primary channel (28) is aligned with said at least one secondary channel (38), said friction assembly (1) further comprising a manifold block (50) which is connected to a suction device and which forms an integral part of said brake head (3) at said upper face (32), said friction assembly (1) being characterized in that said block (50) has a cavity (55) which is connected by a circuit (51) to the suction device and which comprises at least one hole (58) which connects said cavity (55) and said upper face (32) and which is aligned with said at least one secondary channel (38) and in which said connecting ring (8) is able to slide, and in that it comprises a securing mechanism (70) for securing said at least one connecting ring (8) to said block (50) when said at least one connecting ring (8) is arranged in said at least one hole (58) and in said at least one secondary channel (38).

2. Friction assembly (1) according to claim 1, wherein said at least one connecting ring (8) comprises a body (81) and a flange (82) at a first end of said body (81), the distal end of said body (81) carrying tabs (85) which extend radially outwards in said cavity (55), and wherein said securing mechanism (70) comprises said flange (82), said tabs (85), and the internal edge of said at least one hole (58) of said cavity (55).

3. Friction assembly (1) according to claim 1, wherein said at least one connecting ring (8) comprises a body (81) and a flange (82) at a first end of said body (81), the distal end of said body (81) carrying tabs (85) which are plastically deformed radially outwards in said cavity (55), and wherein said securing mechanism (70) comprises said flange (82), said tabs (85), and the internal edge of said at least one hole (58) of said cavity (55).

4. Friction assembly (1) according to claim 1, wherein said at least one connecting ring (8) comprises a body (81) and a flange (82) at a first end of said body (81), the distal end of said body (81) carrying at least one protuberance (86) which extends radially outwards in said cavity (55), wherein said at least one hole (58) carries at least one groove (581) within which said at least one protuberance (86) is adapted to slide, wherein the internal edge of said at least one hole (58) of the cavity (55) comprises a housing (586) adapted to receive said protuberance (86), and wherein said securing mechanism (70) comprises said flange (82), said protuberance (86), and said housing (586).

5. Friction assembly (1) according to any one of claims 1 to 4, further comprising a return mechanism (90) which is adapted to press said ring (8) against said second face (22).

6. Friction assembly (1) according to any one of claims 1 to 5, wherein said fixing mechanism (4, 5) comprises a receiving slide (5) which is formed on said lower face (31), and a dovetail section (4) which is formed on said second face (22) and which is configured to engage with said receiving slide (5).

7. Method for securing at least one connecting ring (8) mounted on a brake head (3) to a manifold block (50) connected to a suction device, said brake head (3) comprising a lower face (31), an upper face (32), and at least one secondary channel (38) of central axis A, said block (50) forming an integral part of said brake head (3) at said upper face (32), the brake head (3) and said connecting ring (8) forming part of a friction assembly (1) for a braking system for railway rolling stock, said friction assembly (1) further comprising a plate (2) made of friction material comprising a first face (21) which is the friction face, a second face (22) which is adapted to be fixed to said lower face (31) by a fixing mechanism (4, 5), and at least one primary channel (28) which connects said first face (21) and said second face (22), said at least one connecting ring (8) being arranged in said at least one secondary channel (38) and establishing a connection with said at least one primary channel (28) when said at least one primary channel (28) is aligned with said at least one secondary channel (38), said method being characterized in that it comprises the following steps: (a) Providing said block (50) with a cavity (55) which is connected by a circuit (51) to the suction device, and with at least one hole (58) which connects said cavity (55) and said upper face (32) and which is aligned with said at least one secondary channel (38) and in which said at least one connecting ring (8) is adapted to slide; (b) Arranging said at least one connecting ring (8) in said at least one hole (58) and in said at least one secondary channel (38) by sliding it along axis A from said lower face (31); (c) Securing said at least one connecting ring (8) to said block (50) by means of a securing mechanism (70); (d) Assembling said plate (2) onto said brake head (3) until said plate (2) covers said at least one connecting ring (8).

8. Method according to claim 7, such that said at least one connecting ring (8) comprises a body (81) and a flange (82) at a first end of said body (81), the distal end of said body (81) carrying tabs (85) which extend radially outwards in their rest positions, and such that, in step (b), said tabs (85) approach each other elastically when said body (81) slides in said at least one hole (58) and in said at least one secondary channel (38), and such that, in step (c), said tabs (85) return to their rest positions and are able to bear against the internal edge of said at least one hole (58) of said cavity (55), said securing mechanism (70) comprising said flange (82), said tabs (85), and said internal edge of the at least one hole (58).

9. Method according to claim 7, such that said at least one connecting ring (8) comprises a body (81) and a flange (82) at a first end of said body (81), the distal end of said body (81) carrying tabs (85) which extend substantially as an extension of said body (81) in their rest positions, such that, in step (b), said body (81) slides freely in said at least one hole (58) and in said at least one secondary channel (38), and such that, in step (c), said tabs (85) are crushed against the bottom of said cavity such that said tabs are plastically deformed radially outwards and are able to bear against the edge of said at least one hole (58) of said cavity (55), said securing mechanism (70) comprising said flange (82), said tabs (85), and said internal edge of the at least one hole (58).

10. Method according to claim 7, such that said at least one connecting ring (8) comprises a body (81) and a flange (82) at a first end of said body (81), the distal end of said body ( 81) carrying at least one protuberance (86) which extends radially outwards, and said at least one hole (58) carrying at least one groove (581) in which said at least one protuberance (86) is adapted to slide, and the internal edge of said at least one hole (58) comprising a housing (586) adapted to receive said at least one protuberance (86) such that, in step (b), said body (81) slides freely in said at least one hole (58) and in said at least one secondary channel (38) until the distal end of said body (81) emerges into said cavity (55), and such that, in step (c), said ring (8) is pivoted about the main axis A until one of said at least one protuberance(s) (86) is located facing said housing (586), then said ring is slid (8) in the opposite direction until one of said protuberance(s) (86) is housed in said housing (586) and bears against the bottom of the housing (586), said securing mechanism (70) comprising said flange (82), said at least one protuberance (86), and said housing (586).