Hydraulic brake distributor

Abstract

A hydraulic brake distributor includes a first inlet (11), a second inlet (16), a first outlet (12), a second outlet (17), a first passageway (13), a branch passageway (22), and a shut-off valve (14, 18, 24), the first inlet being hydraulically connected to a first brake control of a vehicle, the second inlet being hydraulically connected to a second brake control of the vehicle, the first outlet being hydraulically connected to a first brake of the vehicle, the second outlet being hydraulically connected to a second brake of the vehicle, the first passageway placing the first inlet (11) in direct fluid communication with the first outlet (12), the branch passageway placing the first passageway (13) in fluid communication with a first internal cavity (14), the shut-off valve being disposed within the first internal cavity (14) and being actuatable in response to brake fluid being delivered to the second inlet (16) to interrupt fluid communication through the branch passageway (22).

Description

Technical Field

[0001] This invention relates to a hydraulic brake distributor for vehicles, particularly but not exclusively, that can benefit from combined braking, such as bicycles, motorcycles, and scooters. Background Technology

[0002] A combined (or integrated) braking system for two-wheeled vehicles is known, which can simultaneously distribute braking force to both the front and rear wheels. In this combined braking system, instead of assigning the front and rear braking effects to two separate controls, at least one of the two controls simultaneously actuates both the front and rear brakes.

[0003] Chinese Patent Publication No. CN 102582759 B discloses a combined braking system (or integrated braking system) including a hydraulic brake distributor having an outer body comprising two inlets and two outlets for brake fluid. Each of the two inlets is actuated in relation to a corresponding brake control, and the two outlets are fluidly connected to the brakes of the front wheels and the brakes of the rear wheels, respectively. A cylindrical cavity is formed inside the actuator body, communicating with the outlets and inlets. A single piston valve element, provided with a plurality of gaskets, is axially movable within the cylindrical cavity, the gaskets acting against the inner wall of the cylindrical cavity. Actuation of one of the two brake controls causes the valve element to move, resulting in brake fluid flowing simultaneously to both the front and rear brakes. Actuation of the second brake control causes brake fluid to flow toward only one of the brakes, either the front or the rear brake.

[0004] Chinese Patent Publication No. CN 102745293 A discloses a combined braking system including a hydraulic brake distributor. The hydraulic brake distributor has an outer body forming a cylindrical cavity, which communicates with two outlets and two inlets for brake fluid. Two axially aligned and axially movable valve elements are axially movable within the cylindrical cavity. Each valve element has a plurality of sealing gaskets that abut against the inner wall of the cylindrical cavity. Actuation of the first of the two braking controls causes brake fluid to flow from an inlet into the cylindrical cavity, the inlet being positioned midway between the two piston valve elements. Actuation of the first braking control causes both piston valve elements to move, resulting in brake fluid flowing simultaneously towards both the front and rear brakes. Actuation of the second braking control causes brake fluid to flow towards only one of the brakes, either the front or the rear.

[0005] Current known brake distributors have the following drawback: if, during braking, the user actuates one of the distributor's brake controls and then simultaneously initiates a second brake control, the first control will receive a hydraulic pulse triggered by the overpressure caused by the second control. This pulse tends to act in the opposite direction to the action being transmitted from the rider to the first control, causing it to return to the release position. In other words, because the lever already being pulled tends to release when the other brake lever is pulled, the user will feel the first actuated brake being released. Summary of the Invention

[0006] The purpose of this invention is to provide a hydraulic distributor that is not affected by the disadvantages described above.

[0007] According to one concept, the present invention provides a hydraulic brake distributor comprising at least one first inlet, at least one second inlet, a first outlet, a second outlet, a first channel, a branch channel, and a shut-off valve. The at least one first inlet is hydraulically connected to a first brake control of a vehicle, the at least one second inlet is hydraulically connected to a second brake control of the vehicle, the first outlet is hydraulically connected to a first brake of the vehicle, and the second outlet is hydraulically connected to a second brake of the vehicle. The first channel provides direct fluid communication between the first inlet and the first outlet, the branch channel provides fluid communication between the first channel and a first internal cavity, and the shut-off valve is disposed within the first internal cavity and is actuated in response to brake fluid supplied to the second inlet to interrupt fluid communication via the branch channel.

[0008] According to another concept, a hydraulic brake distributor is provided, comprising: At least one first inlet, which is hydraulically connected to the vehicle’s first braking control; At least one second inlet, which is hydraulically connected to the vehicle’s second brake control; The first outlet is hydraulically connected to the vehicle's first brake. The second outlet is hydraulically connected to the vehicle's second brake. A first internal cavity extends longitudinally and has an end that forms a hydraulic shut-off cavity, which is hydraulically connected to a second inlet. A floating stop piston is received longitudinally in a first internal cavity and elastically driven toward the stop cavity; The first channel directly fluidly connects the first inlet and the first outlet; A branch channel that allows the first channel to be fluidly connected to the first internal cavity; The second longitudinally extending internal cavity communicates with the first internal cavity via at least two internal passages. The second internal cavity has a first end and a second end. The first end forms a hydraulic actuation chamber, which is hydraulically connected to the first internal cavity via a first of the internal passages. The second end is hydraulically connected to a second outlet. At least one second channel for interconnecting the internal passages, the interconnecting passage providing fluid communication between the shut-off cavity and the second internal cavity and opening at a point on the second internal cavity, located longitudinally midway between the first internal passage and the second outlet; At least one floating piston valve element, in a second internal cavity, is elastically driven toward a hydraulically actuated chamber; The stop piston has the following characteristics: In the invalid position, the stop piston is in a position that allows fluid communication between the branch channel and the first channel leading to the hydraulic actuation chamber via the first internal cavity, and In the active position, the cut-off chamber is pressurized by the brake fluid supplied to the second inlet, and the cut-off piston closes the branch passage in the active position. The piston valve element therein has the following characteristics: In the invalid position, the actuation chamber is pressurized, and the piston valve element is allowed to fluidly communicate from the shut-off chamber to the second outlet via the interconnecting passage through the second internal cavity. Following the pressurization of the hydraulic actuation chamber, a position is formed in which a sealing element on the piston valve element, acting in sliding contact against the second internal cavity, is located longitudinally at the midpoint between the interconnection passage and the second outlet, such that the sealing element does not allow direct fluid communication from the shut-off chamber to the second outlet through the interconnection passage via the second internal cavity, and such that pressurization of the shut-off chamber can further move at least a portion of the piston valve element toward the second outlet. Attached Figure Description

[0009] Some preferred, but non-limiting, embodiments of the hydraulic brake distributor according to the invention will now be described with reference to the accompanying drawings, in which: Figures 1 and 2 are perspective views of a hydraulic brake distributor according to a specific embodiment of the present invention from different angles. Figures 3 to 8 This is a schematic longitudinal sectional view illustrating a hydraulic brake distributor according to a specific embodiment of the invention under various operating conditions; and Figures 9 to 11 This is a schematic cross-sectional view illustrating a hydraulic brake distributor according to another specific embodiment of the invention under various operating conditions. Detailed Implementation

[0010] Please refer to Figure 1 to the beginning. Figure 3Reference numeral 10 indicates the entire body of the hydraulic brake distributor. The body 10 is made of a rigid material, such as aluminum alloy, in which a plurality of internal cavities, inlets and outlets, and internal channels communicating between the aforementioned are formed.

[0011] The first inlet 11 is hydraulically connected to the first brake pump (not shown) and actuated by a corresponding first control (not shown). In a bicycle, the first control is typically a control lever mounted on the left side of the handlebars. The first outlet 12 is hydraulically connected to the vehicle's first brake, typically the brake caliper of the front wheel.

[0012] The first inlet 11 and the second outlet 12 are directly connected to each other via a first internal passage 13, which includes two sections 13a and 13b respectively connected to the first inlet 11 and the first outlet 12. Direct hydraulic connection may directly actuate the front wheel brakes upon first control actuation.

[0013] Two interconnected internal cavities 14 and 15 are formed in the body 10: a first cavity 14 and a second cylindrical internal cavity 15. In this example, the first cavity has a single-diameter cylindrical shape, and the second cylindrical internal cavity 15 has two diameters in this example. The second cylindrical internal cavity 15 has a smaller diameter segment 15a and a larger diameter segment 15b.

[0014] The second inlet 16 is hydraulically connected to the second brake pump (not shown) and actuated by a corresponding second control (not shown). In a bicycle, the second control may be a control lever mounted on the right side of the handlebars. The second outlet 17 is hydraulically connected to the vehicle's second brake, typically the brake caliper of the rear wheel.

[0015] The brake distributor is combined with the shut-off valve (or shut-off valve), which is intended to selectively isolate the first brake from the operation of the rest of the braking system, thereby making the control of the first brake unresponsive to the action of the second control.

[0016] The terms "front" and "rear" regarding the first and second brakes, and the first and second controls, should not be construed as limiting the application of brake distributors to vehicles such as bicycles. As will become clear from the following description, the first inlet and first outlet of the direct hydraulic connection can be interchanged so that the first brake control is connected to outlet 12 and the first brake is connected to the first inlet 11.

[0017] A shut-off valve is formed by a shut-off valve or piston element 18, which is axially movable within the first internal cavity 14. A compression spring 19 elastically drives the shut-off piston 18 toward the bottom wall 20 of the first internal cavity 14, and the passage 21 communicating with the second inlet 16 opens at the bottom wall 20.

[0018] In this document, terms indicating position and orientation, such as "axial" or "longitudinal," and "lateral" or "radial," are understood to refer to the direction in which the piston element described herein extends and moves. Terms such as "upstream" or "downstream" are understood to refer to the direction of fluid flow actuated by one of the braking controls.

[0019] A branch channel 22, which communicates with the first internal channel 13, establishes fluid communication between the first internal channel 13 (and therefore the first inlet 11 and the first outlet 12) and the first internal cavity 14. The branch channel 22 opens onto the first internal cavity 14 via a port 23, which is located longitudinally at the midpoint between the bottom wall 20 and the compression spring 19.

[0020] The first internal cavity 14 has an end section that includes a bottom wall 20, and together with the side end of the shut-off piston 18 facing the bottom wall 20, it forms a hydraulic shut-off cavity 24 (in Figure 5 (This is best seen in the middle).

[0021] The hydraulic shut-off chamber 24 is fluidly connected to the second inlet 16 via the channel 21 and can be expanded by the braking fluid sent from the second inlet 16, which moves the shut-off piston 18 against the elastic action of the compression spring 19.

[0022] The shut-off piston 18 preferably has an end section 18b, which has a recess or a reduced diameter, the end section facing the bottom wall 20 and forming a portion of the hydraulic shut-off chamber 24.

[0023] The stop piston 18 has an intermediate section 18a with a reduced diameter. The intermediate section 18a and the cylindrical wall of the first internal cavity 14 together define an axially extending annular gap 25. The annular gap 25 is longitudinally located between two sealing gaskets 26 and 27, which are disposed on the stop piston 18 and act in sliding contact with the first internal cavity 14.

[0024] One or two of the additional sealing gaskets 56 and 57 that slide against the first internal cavity 14 are disposed on the stop piston 18 in a longitudinal position between the port 23 of the branch channel 22 and the stop cavity 24.

[0025] As will be explained below, the shut-off valve has the effect of preventing the rider from experiencing the subsequent second control action after the first control has been actuated, as described in the introduction.

[0026] The second internal cavity 15 movably houses at least one floating piston valve actuator 30 in an axially movable manner. Figures 3 to 8 In a specific embodiment, it is designed as a double piston, which includes two components 31 and 32 that can move relative to each other in the longitudinal direction.

[0027] The second internal cavity 15 is directly connected to the second outlet 17, which is hydraulically connected to the vehicle's second brake (rear brake).

[0028] The stop cavity 24 is hydraulically connected to the second internal cavity 15 via two longitudinally spaced inlet ports 28 and 29 for actuation of the second brake.

[0029] A compression spring 33 is disposed in the second hydraulic chamber 15, and the compression spring 33 elastically biases the floating piston valve actuator 30 toward the bottom wall 34 of the second internal cavity 15. The second internal cavity 15 has an end section that includes the bottom wall 34, and together with the side end of the floating piston valve actuator 30 facing the bottom wall 34, it forms a cavity 36 for actuating the floating piston actuator 30. A passage 35 provides fluid communication between the annular gap 25 in the first internal cavity 14 and the hydraulic actuation chamber 36 in the second internal cavity 15.

[0030] exist Figures 3 to 8 In the specific embodiment shown, the floating piston valve actuator 30 includes a first inner or central piston element 31 and a second outer piston element 32. The second outer piston element 32 is coaxially mounted on the outside of the first piston element 31 and slides telescopically on the first piston element 31.

[0031] The first piston element 31 has an end face 37 facing the bottom wall 34 of the second internal cavity 15. The end face 37 is preferably formed with a recess 38, or has a portion with a reduced diameter to form a hydraulic actuation cavity 36.

[0032] The first piston element 31 includes a base 39, a rod 41, and a middle portion 40. The base 39 has a larger diameter. The rod 41 is axially opposed to the base 39 and has a smaller diameter or lateral dimension than the base 39. The middle portion 40 has an intermediate diameter between the base 39 and the rod 41. Two radial shoulders 42 and 43 are defined between the base 39, the middle portion 40, and the rod 41.

[0033] The base 39 has at least one (two in this example) sealing gasket 44, 45 that slides against the smaller diameter section 15a of the second internal cavity 15.

[0034] The second piston element 32 has a varied but generally tubular shape, through which the middle portion 40 and the rod portion 41 of the first piston element 31 pass. The second piston element 32 forms a tubular portion 46 and a head 47. The tubular portion 46 is slidably mounted on the axial middle portion 40 of the first piston element 31, and the head 47 has a sealing gasket 48, which slides against the larger diameter section 15b of the second internal cavity 15.

[0035] The dual-diameter central passages 50 and 51 extend longitudinally through the second piston element 32 and have a shoulder 52 ( Figure 7 The wider lateral section 50 and the narrower lateral section 51 are joined together.

[0036] The first and second piston elements are sealed together by a sliding contact sealing element 49.

[0037] exist Figures 3 to 8 In the example embodiment, the middle portion 140 of the first piston element carries a sealing gasket 49, which slides against a cylindrical cavity 50 formed in the tubular portion 46 of the second piston element 32.

[0038] The actuation chamber 36 of the floating piston valve actuator 30 is hydraulically sealed relative to the second outlet 17 by sealing elements 44, 45, 48, and 49 collectively mounted on the floating piston valve actuator 30.

[0039] In the specific embodiment shown here, in order to optimize the size of the brake distributor, two internal cavities 14 and 15 are parallel and adjacent, and accommodate individual piston elements biased in parallel and opposite directions.

[0040] Brake distributor has in Figure 3 The stop position is shown in the diagram. The stop piston 18 is in the retracted and inactive position with the spring 19 relaxed. The stop piston 18 is close to the bottom wall 20 of the first cylindrical cavity 14, and the port 23 of the branch channel 22 is in fluid communication with the annular gap 25. The annular gap 25 is in fluid communication with the hydraulic chamber 36 via the passage 35. The floating piston valve element 30 is in the inactive and retracted position. The compression spring 33 elastically drives the floating piston valve brake 30 toward the bottom wall 34 of the second internal cavity 15; the compression spring 33 acts against the second piston element 32, which, due to its close contact between the radial shoulders 42 and 52, also drives the first piston element 31 toward and against the bottom wall 34 of the second internal cavity 15.

[0041] Depend on Figure 3 At the resting position, when the user actuates the first brake control, the aforementioned control delivers brake fluid to the first inlet 11 of the brake distributor. A first portion of the input fluid flows directly through channels 13a and 13b to the first outlet 12, directly actuating the first brake. A second portion of the fluid entering the first inlet 11 travels to branch 22, through port 23 to the annular gap 25 surrounding the stop piston 18 without moving the stop piston 18, and reaches the base of the hydraulic chamber 36. Figure 4 The action of the compression spring 33 pushes the two piston elements 31 and 32 to the right.

[0042] The piston elements 31 and 32, in response to the forward motion of the brake fluid fed into the hydraulic actuation chamber 36, reduce the volume of brake fluid available inside section 15b of the second internal cavity 15, and cause pressurized brake fluid to be discharged from the second outlet 17 toward the second brake.

[0043] It should be noted that the brake fluid sent from the first control is separated from the brake fluid reaching the second brake and does not reach the second brake; in fact, the brake fluid flowing into branch 22 is still contained in hydraulic chamber 36 and does not reach the second outlet 17.

[0044] Furthermore, it should be noted that the braking fluid passing through the first internal cavity in the passage from branch channel 22 to actuation chamber 36 does not cause the cut-off piston 18 to move.

[0045] The two piston elements 31 and 32 are in their fully extended positions ( Figure 4 This can be determined, for example, by means of a longitudinally adjustable end stop element 53 of a threaded coupling 54. In the maximum extended position, the end of the rod 41 is close to the end stop element 53.

[0046] In some specific embodiments, the distribution of braking can be selectively prohibited by adjusting the position of the end stop element 53, so that the end stop element 53 advances to a position where the floating annular piston element 30 is blocked longitudinally against the bottom wall 34 of the second internal cavity 15. Figure 8 In the operating mode, when the brake fluid is introduced into the first inlet 11, the fluid simply travels directly through the channel 13 to the first outlet 12, without any fluid movement through the branch 22.

[0047] By selectively fabricating the second internal cavity 15 into two sections with different diameters, it is possible to adjust the total amount of brake fluid supplied to the second brake. By adjusting the size of the second section 15b of the second internal cavity 15 to have a larger diameter than the corresponding cavity in its first section 15a that receives brake fluid from the first brake control, a fixed amount of brake fluid is introduced into the left side portion 15a of the second hydraulic cavity. This will cause more brake fluid to flow out from the right side and wider section 15b of the second cavity towards the second brake due to the translation of the floating piston valve element 30. In other words, a smaller amount of brake fluid introduced upstream of the floating piston valve actuator 30 will move a larger amount of brake fluid downstream of the piston valve actuator. The larger the diameter of the second section of the second internal cavity relative to the first section 15a, the greater the braking force transmitted to the second brake due to the actuation of the first brake control.

[0048] In the role of Figures 3 to 8In some variants of the shown embodiment (not shown), the second internal cavity 15 may have a single diameter. In other different embodiments (not shown), the second internal cavity may have sections having a smaller diameter in the second section where the second outlet 17 is located, and a larger diameter in the first section that receives braking fluid from the first inlet 11.

[0049] If the user only actuates the second brake control, typically intending to actuate the second brake (rear brake), the brake fluid introduced into the distributor via the second inlet 16 will flow through the distributor and toward the second outlet 17. Specifically, the brake fluid from the second inlet 16 will reach the shut-off chamber 24 of the first internal cavity 14, moving the shut-off piston from the rest position ( Figure 3 Move to the effective location ( Figure 5 The fluid flows through the inlet port 28 into the section 15b of the second internal cavity and from there towards the second brake to the second outlet 17. Sealing gaskets 56 and 57 disposed on the stop piston 18 prevent brake fluid from the stop cavity 24 from reaching the branch passage 22, and therefore the first outlet 12 and the first inlet 11. Actuating only the second brake control, and not the first brake control, will result in actuation of only the second brake because the stop valve prevents any fluid communication from the second inlet to the first outlet 12.

[0050] Please note that actuating only the second braking control will not be felt by the user in the first control due to the sealing gaskets 56 and 57 on the stop piston 18 that prevent fluid from flowing from the stop chamber 24 to the first inlet 11. This is because the gaskets 27 on the stop piston 18 (…) Figure 5 The valve is positioned between the branch channel 22 and the channel 35 leading to the hydraulic chamber 36, so that while the user is still actuating the second brake control, any actuation of the first brake control will cause the brake fluid to be delivered directly and exclusively from the first inlet 11 to the first outlet 12 via the channel 13, without causing any additional brake fluid to be delivered to the second outlet.

[0051] Please refer to Figure 6 and Figure 7 This describes the operation of a hydraulic distributor that first acts on a first braking control, typically primarily controlling the front braking, and subsequently also actuates a second braking control. Actuating the first control causes fluid to travel directly from the first inlet 11 to the first outlet 12, and the flow is divided; the flow is partially diverted through branch passage 22, flowing into the annular gap 25 surrounding the stop piston 18, and thus reaching the hydraulic actuation chamber 36 of the floating piston valve actuator 30 via passage 35.

[0052] The two inner and outer piston elements 31 and 32 of the floating piston valve actuator 30, along with the anti-spring 33, move to the right as a single unit. Figure 6 This causes a first amount of brake fluid contained in the second internal cavity 15 downstream of the dual pistons to flow from the second internal cavity to the second brake until the inner piston element reaches the stop 53. The compression spring 33 is only partially compressed. Therefore, in the initial braking phase, the second brake is actuated only by the first control. Please note ( Figure 6 The downstream translation (to the right) of the floating piston valve actuator 30 will cause the gasket 48 of the outer piston element 32 to cross the two interconnecting ports 28, 29, thus preventing the brake fluid from traveling directly from the shut-off chamber 24 to the second outlet 17.

[0053] When the user also acts on the second control ( Figure 7 Since the caliper of the second brake receives another pressure pulse, the braking force acting on the second brake will increase, as will be explained below. Brake fluid introduced through the second inlet 16 reaches the shut-off chamber 24 of the first internal cavity 14, moving the shut-off piston 18 from the rest position. Figure 6 Move to the effective location ( Figure 7 The gaskets 56 and 57 of the stop piston 18 are longitudinally positioned between the stop chamber 24 and the branch channel 22, resulting in the first inlet 11 and its upstream first control being unaffected by the pressurization in the stop chamber 24. Consequently, the user will not experience the effect of the second control actuated after the first control has been activated.

[0054] Brake fluid travels from the shut-off chamber 24 through the interconnecting ports 28 and 29 into the second internal cavity 15 upstream of the gasket 48 surrounding the outer piston 32. This causes further translation of the second outer piston element 32, which slides telescopingly on the first piston element 31, thus further compressing the spring 33 and causing a further increase in brake fluid pressure toward the second outlet 17 and the second brake. This transmits an additional braking force to the second brake, in addition to the braking force already applied by the actuation of the first control.

[0055] When the user applies the second braking control and subsequently actuates the first braking control at the same time as the second, the distributor will make the two braking actions independent of each other according to the non-combined braking mode. The braking action caused by the actuation of the second control involves brake fluid being delivered directly to the second brake from the second inlet 16, through the section 15b of the second hydraulic cavity downstream of the stop chamber 24 and the floating piston valve actuator 30, to the second outlet 17. Pressurization in the stop chamber 24 causes the stop piston 18 to move to the left, subsequently closing the branch passage 22. Therefore, the pressurized brake fluid then flowing to the first inlet 11 will, according to the braking mode independent of the actuation of the second controller, cause the fluid to travel directly from the first inlet 11 through passage 13 to the first outlet 12.

[0056] exist Figures 9 to 11 In one specific embodiment shown, the floating piston valve actuator 30 consists of a single piston element. This element, when the user actuates the first braking control, expands from its rest position due to the expansion of the hydraulic chamber 36. Figure 9 ) Perform the first forward movement ( Figure 10 ), and when the user also initiates the second braking control, a second additional forward motion is executed ( Figure 11 ).

[0057] It is understood that the braking effect caused by acting on the second control on the second brake (e.g., the brake on the rear wheel) will only allow direct flow from the first inlet to the first outlet due to the action of the shut-off valve, and will not be perceived by the user's hand that actuates the first control.

[0058] Please note that the connections indicated here as the first inlet and the first outlet can be interchangeably connected to the first braking control and the first brake as stated, or vice versa.

[0059] Furthermore, according to a variant operating mode where the first brake is a front brake and an independent brake as discussed above, the connections of the distributor can be reversed. According to this variant connection mode, the first outlet is hydraulically connected to the rear brake, and the second outlet is connected to the front brake. As a result, the distributor causes only the rear wheels to be braked when the first control is actuated, and causes combined braking on both the front and rear wheels when the second control is actuated; in the above operating mode, the rear wheels are independent wheels.

[0060] Various ideas and specific embodiments of the brake distributor have been described; please understand that each specific embodiment can be combined with any other specific embodiment. Furthermore, specific embodiments and details of the structure can vary extensively from those described and illustrated merely as non-limiting examples, without departing from the scope of the invention as defined in the appended claims.

Claims

1. A hydraulic brake distributor, comprising: At least one first inlet is hydraulically connected to the vehicle's first braking control; At least one second inlet is hydraulically connected to the vehicle's second braking control; The first outlet is hydraulically connected to the first brake of the vehicle; The second outlet is hydraulically connected to the vehicle's second brake. The first channel allows direct fluid communication between the first inlet and the first outlet; A branch channel is provided to allow the first channel to be in fluid communication with a first internal cavity, the first internal cavity extending longitudinally and having an end that forms a hydraulic shut-off cavity, which is hydraulically connected to the second inlet. as well as A shut-off valve comprising a floating shut-off piston disposed within a first internal cavity and a hydraulic shut-off chamber, the shut-off piston being received longitudinally in the first internal cavity and resiliently driven toward the shut-off chamber, and actuated in response to brake fluid supplied to a second inlet to interrupt fluid communication via the branch passage.

2. The hydraulic brake distributor as claimed in claim 1, comprising: A longitudinally extending second internal cavity communicates with the first internal cavity via at least two internal passages. The second internal cavity has a first end and a second end. The first end forms a hydraulic actuation cavity, which is hydraulically connected to the first internal cavity via the first internal passage of the at least two internal passages. The second end is hydraulically connected to the second outlet. At least one interconnecting passage for interconnection between the at least two internal passages, the at least one interconnecting passage providing fluid communication between the hydraulic shut-off chamber and the second internal cavity and opening to the second internal cavity at a point midway along the longitudinal direction between the first internal passage and the second outlet; At least one floating piston valve actuator, within the second internal cavity, is elastically driven toward the hydraulic actuation chamber; The shut-off piston has: In an invalid position, the stop piston allows fluid communication via the first internal cavity between the branch channel and the first internal passage leading to the hydraulic actuation chamber. In the active position, the hydraulic shut-off chamber is pressurized by the brake fluid supplied to the second inlet, and the shut-off piston closes the branch passage in the active position. And the piston valve actuator therein has: In the invalid position, the actuation chamber is not pressurized, and the piston valve actuator is allowed to fluidly communicate from the hydraulic shut-off chamber to the second outlet via the interconnection passage through the second internal cavity in the invalid position. In response to pressurization of the hydraulic actuation chamber, the piston valve actuator extends at least partially toward the second outlet. In this at least partially extended position, a sealing element that slides against the second internal cavity on the piston valve actuator is located longitudinally at a midpoint between the at least one interconnecting passage and the second outlet. This prevents the sealing element from directly fluidly communicating with the second outlet from the hydraulic shut-off chamber through the second internal cavity via the at least one interconnecting passage, and thereby allows pressurization of the hydraulic shut-off chamber to move at least a portion of the piston valve actuator further toward the second outlet.

3. The hydraulic brake distributor of claim 2, wherein the stop piston has an intermediate section having a reduced diameter longitudinally contained between two sealing gaskets, the sealing gaskets being disposed on the stop piston and slidingly contacting the first internal cavity, thereby causing the reduced diameter intermediate section and the first internal cavity to together define an axially extending annular gap, the axially extending annular gap being in fluid communication with the first internal passage and the branch passage in the inactive position of the stop piston.

4. The hydraulic brake distributor of claim 2, wherein the shut-off piston has an end section having a recess or a reduced diameter, the end section facing the bottom wall of the first internal cavity and forming a portion of the hydraulic shut-off cavity.

5. The hydraulic brake distributor of claim 2, wherein the stop piston has at least one additional sealing gasket, which slides against the first internal cavity and is mounted on the stop piston in at least one position, the position being longitudinally intermediate between the hydraulic stop cavity and the port of the branch channel opening into the first internal cavity.

6. The hydraulic brake distributor as claimed in claim 2, wherein the hydraulic shut-off chamber is hydraulically connected to the second internal cavity via two longitudinally spaced interconnecting passages.

7. The hydraulic brake distributor as claimed in claim 2, wherein the second internal cavity is a double-diameter cylindrical cavity, the second internal cavity having a section with a smaller diameter and a section with a larger diameter.

8. The hydraulic brake distributor of claim 2, wherein the piston valve actuator is designed as a dual-piston assembly comprising two components movable relative to each other in the longitudinal direction, the piston valve actuator comprising: First radial inner piston element, The second radially outer piston element is coaxially mounted and telescopically slidable on the first radially inner piston element. At least one sliding contact sealing element performs a sliding contact sealing function between the first radially inner piston element and the second radially outer piston element.

9. The hydraulic brake distributor of claim 8, wherein the first radially inner piston element has an end face forming a recess or end portion with a reduced diameter, the end face facing the bottom wall of the second internal cavity, wherein the recess or end portion with the reduced diameter defines a portion of the hydraulic actuation cavity.

10. The hydraulic brake distributor of claim 8, wherein the first radially inner piston element includes a base, a rod, and a middle portion, the base having a larger diameter, the rod being longitudinally opposed to the base and having a smaller diameter or lateral dimension than the base, and the middle portion having an intermediate diameter between the diameter of the base and the diameter of the rod.

11. The hydraulic brake distributor of claim 10, wherein the base of the first radially inner piston element has at least one sealing gasket that slides against the second internal cavity.

12. The hydraulic brake distributor of claim 10, wherein the second radially outer piston element has an overall irregular tubular shape and is inserted and passes through the middle portion and rod portion of the first radially inner piston element.

13. The hydraulic brake distributor of claim 10, wherein the second radially outer piston element has a tubular portion and a head, the tubular portion being slidably mounted axially on the axially intermediate portion of the first radially inner piston element, and the head having the sealing element, the sealing element slidingly contacting and abutting against the second internal cavity.

14. The hydraulic brake distributor of claim 10, wherein the second radially outer piston element has a dual-diameter central passage extending longitudinally through the second radially outer piston element and has a wider section and a narrower section joined by a shoulder.

15. The hydraulic brake distributor of claim 14, wherein the middle portion of the first radially inner piston element carries the at least one sliding contact sealing element, the at least one sliding contact sealing element acting in sliding contact against the wider section of the double-diameter central passage of the second radially outer piston element.

16. The hydraulic brake distributor of claim 8, wherein the compression spring drives the second radially outer piston element longitudinally toward the first radially inner piston element and toward the hydraulic actuation chamber.

17. The hydraulic brake distributor of claim 2, wherein the piston valve actuator comprises a single piston element, the single piston element having: The sealing element slides against the second internal cavity and, in the at least partially extended position, is located longitudinally at the midpoint between the at least one interconnecting passage and the second outlet. At least one additional sealing gasket, at the end of the piston valve actuator closest to the hydraulic actuation chamber, slides against the second internal cavity.

18. The hydraulic brake distributor of claim 2, wherein the first internal cavity and the second internal cavity are parallel and adjacent.

19. The hydraulic brake distributor of claim 18, wherein the shut-off piston in the first internal cavity is biased toward a first direction, and the piston valve actuator in the second internal cavity is biased toward a second direction parallel to and opposite to the first direction.

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