Hydraulic brake distributor

Abstract

1. A hydraulic brake distributor comprising: a first inlet (11) hydraulically connectable to a first brake control of a vehicle; a second inlet (16) hydraulically connectable to a second brake control of the vehicle; a first outlet (12) hydraulically connectable to a first brake of the vehicle; a second outlet (17) hydraulically connectable to a second brake of the vehicle; a first passage (13) placing the first inlet (11) and the first outlet (12) in direct fluid communication; a branch passage (22) placing the first passage (13) in fluid communication with a first internal cavity (14); and a cut-off valve (14, 18, 24) disposed within the first internal cavity (14) and operable in response to brake fluid delivered to the second inlet (16) to cut off fluid communication through the branch passage (22).

Description

Technical Field

[0001] The present invention relates to a hydraulic brake distributor for two-wheeled vehicles that benefit from a combined brake, not exclusively, but particularly for bicycles, motorcycles, and scooters, for example.

Background Art

[0002] A combined (or integral) brake system for two-wheeled vehicles that can distribute braking force to both the front and rear wheels simultaneously is known. In a combined brake system, instead of allocating the front and rear brake operations to two separate controls, at least one of the two controls can operate the front and rear brakes simultaneously.

[0003] Patent document CN102582759B discloses a combined brake system (or integral brake system) comprising a hydraulic brake distributor having an outer body with two inlets and two outlets for brake fluid. Each of the two inlets is operably associated with a related brake control, and the two outlets are fluidly connected to the front-wheel brake and the rear-wheel brake, respectively. A cylindrical cavity is formed within the body of the actuator, and the cavity communicates with the outlets and the inlets. A single piston valve element with a sealing gasket acting on the inner wall of the cylindrical cavity is axially movable within the cylindrical cavity. Upon activation of the first of the two brake controls, the valve moves, and accordingly, brake fluid flows simultaneously to both the front and rear brakes. Upon activation of the second brake control, the brake fluid flows only to either the front or the rear brake.

[0004] Patent document CN102745293A discloses a combined brake system having a hydraulic brake distributor having an outer body that forms a cylindrical cavity communicating with two outlets and two inlets for brake fluid. Two separate valve elements, axially aligned and axially movable within the cavity, are positioned within the cylindrical cavity to allow axial movement. Sealing gaskets acting on the inner wall of the cylindrical cavity are provided for the valve elements. Activation of a first of two brake controls causes brake fluid to flow into the cylindrical cavity from an inlet positioned midway between the two piston valve elements. Activation of the first brake control causes both piston valve elements to move, and consequently, brake fluid flows simultaneously toward both the front and rear brakes. Activation of the second brake control causes brake fluid to flow toward either the front or rear brake only.

[0005] Currently known brake distributors have the following drawbacks: If, during braking, the user has already activated one of the brake-distributing controls and then simultaneously begins activating the second control, the first control receives a hydraulic pulse triggered by the overpressure induced by the operation of the second control. This pulse tends to return the first control to the release position, contrary to what the rider would do if the first control were activated. In other words, when the other brake control lever is pulled, the already pulled control lever tends to open, causing the user to feel the first activated brake being released. [Overview of the project]

[0006] The object of the present invention is to provide a hydraulic distributor that is not affected by the above-mentioned drawbacks.

[0007] According to one aspect of the present invention, the above and other objectives and advantages, which will be better understood below, are achieved by a hydraulic brake distributor having the features defined in claim 1. Preferred embodiments of the distributor are defined in the dependent claims.

[0008] In one embodiment, the present invention provides a hydraulic brake distributor having at least one first inlet that can be hydraulically connected to a first brake control of a vehicle, at least one second inlet that can be hydraulically connected to a second brake control of a vehicle, a first outlet that can be hydraulically connected to a first brake of a vehicle, a second outlet that can be hydraulically connected to a second brake of a vehicle, a first passage that sets the first inlet and the first outlet to direct fluid communication, a branch passage that sets the first passage to fluid communication with a first internal cavity, and a cut-off valve disposed in the first internal cavity and operating in response to brake fluid supplied to the second inlet, which cuts off fluid communication through the branch passage.

[0009] In a further manner, At least one first inlet that can be hydraulically connected to the first brake control of the vehicle, At least one second inlet that can be hydraulically connected to the vehicle's second brake control, A first outlet that can be hydraulically connected to the first brake of the vehicle, A second outlet that can be hydraulically connected to the vehicle's second brake, The first internal cavity having an end that extends in the longitudinal direction and forms a hydraulic cutting chamber that is hydraulically connected to the second inlet, A floating cutting piston is received longitudinally within the first internal cavity and elastically biased toward the cutting chamber, A first passage that sets the first inlet and the first outlet into direct fluid communication, A branching passage that establishes the first passage for fluid communication with the first internal cavity, A second longitudinally extending internal cavity communicating with the first internal cavity via at least two internal passages, the second internal cavity having a first end forming a hydraulically operating chamber that is hydraulically connected to the first internal cavity via the first of the internal passages, and a second end that is hydraulically connected to the second outlet, At least one second communication passage for communication between the internal passages, providing fluid communication between the cutting chamber and the second internal cavity, and opening into the second internal cavity at a position midway in the longitudinal direction between the first internal passage and the second outlet, At least one floating piston valve element in the second internal cavity, elastically biased toward the hydraulic operating chamber, It has, The aforementioned cutting piston is A passive position that allows fluid to communicate with the hydraulic operating chamber through the first internal cavity between the branch passage and the first passage, The cutting chamber is pressurized by the brake fluid supplied to the second inlet, and the cutting piston is in an operating position that closes the branch passage. It has, The aforementioned piston valve element is The working chamber is in a passive position where it is not pressurized, and the piston valve element is allowed to communicate fluidly through the second internal cavity from the communication passage from the cutting chamber to the second output, and It has, In response to the pressurization of the hydraulic operating chamber, the piston valve element is at least partially expanded toward the second outlet, and in this position, the sealing element of the piston valve element that slides against the second internal cavity is positioned at an intermediate longitudinal position between the communication passage and the second outlet, the sealing element does not allow direct fluid communication through the second internal cavity from the communication passage from the cutting chamber to the second outlet, and the pressurization of the cutting chamber allows at least a portion of the piston valve element to move further toward the second outlet. A hydraulic brake distributor is provided. [Brief explanation of the drawing]

[0010] Several preferred, but not limited, embodiments of the hydraulic brake distributor according to the present invention will be described with reference to the following accompanying drawings.

[0011] Figures 1 and 2 are perspective views from different angles of a hydraulic brake distributor according to one embodiment of the present invention.

[0012] Figures 3 to 8 are schematic longitudinal cross-sectional views showing a hydraulic brake distributor according to one embodiment of the present invention under various operating conditions.

[0013] Figures 9 to 11 are schematic cross-sectional views showing a hydraulic brake distributor according to another embodiment of the present invention under various operating conditions. [Modes for carrying out the invention] Detailed description of the invention

[0014] Referring first to Figures 1 to 3, reference numeral 10 indicates the body of the hydraulic brake distributor as a whole. The body 10 is made of a rigid material, such as an aluminum alloy, into which multiple internal cavities are formed, and the body 10 has multiple internal cavities, inlets and outlets, as well as internal passages for communication between them.

[0015] The first inlet 11 is hydraulically connected to a first brake pump (not shown) and can be actuated by an associated first control (not shown). In a bicycle, this first control may typically be a control lever mounted on the left side of the handlebars. The first outlet 12 may be hydraulically connected to a first brake of the vehicle, typically a brake caliper on the front wheel.

[0016] The first inlet 11 and the first outlet 12 are directly connected to each other by a first internal passage 13 having two parts 13a and 13b connected to the first inlet 11 and the first outlet 12, respectively. This direct hydraulic communication allows the front wheel brakes to be directly activated when the first control is activated.

[0017] Two mutually communicating internal cavities 14, 15 are formed in the body 10. The first cavity 14 has a cylindrical shape of a single diameter in this example, and the second cylindrical internal cavity has a double diameter with a portion 15a having a smaller diameter and a portion 15b having a larger diameter in this example.

[0018] The second inlet 16 is hydraulically connected to a second brake pump (not shown) and can be actuated by an associated second control (not shown). In a bicycle, the second control may be a control lever attached to the right side of the handlebar. The second outlet 17 can be hydraulically connected to a second brake of the vehicle, typically a brake caliper of the rear wheel.

[0019] The brake distributor incorporates a cut-off valve (or shut-off valve) intended to selectively cut off the operation of the first brake from the rest of the brake system, thereby preventing the control of the first brake from responding to the operation of the second control.

[0020] Regarding the first and second brakes and the first and second controls, it should be stated that the terms "front" and "rear" are not limited to their application to the brake distributor of a vehicle, such as a bicycle. As will become apparent from reading the following description, the first inlet and the first outlet, which are directly hydraulically connected, can be interchanged by the first brake control connected to the outlet 12 that may be interchanged and the first brake connected to the first inlet 11.

[0021] The cut-off valve is formed by a cut-off valve or piston element 18 that is axially movable within the first internal cavity 14. The compression spring 19 elastically biases the cut-off piston 18 towards the bottom wall 20 of the first internal cavity 14 where the passage 21 communicating with the second inlet 16 opens.

[0022] In this context, terms indicating positions and arrangements such as "axial direction", or "longitudinal direction", and "lateral direction", or "radial direction" are understood for referring to the direction in which the piston element described in this specification extends and moves. Terms such as "upstream side" or "downstream side" are understood for referring to the direction of fluid flow actuated by one of the brake controls.

[0023] The branch passage 22 communicating with the first internal passage 13 establishes fluid communication between the first internal passage 13 (and thus the first inlet 11 and the first outlet 12) and the first internal cavity 14. The branch passage 22 opens into the first internal cavity by a port 23 disposed at a longitudinal intermediate position between the bottom wall 20 and the compression spring 19.

[0024] The first internal cavity 14 has a bottom wall 20 and has an end that forms a hydraulic cutting chamber 24 (best seen in FIG. 5) together with the side surface of the cutting piston 18 facing the bottom wall 20.

[0025] The hydraulic cutting chamber 24 is in fluid communication with the second inlet 16 by a passage 21 and can be expanded as a result of the delivery of brake fluid from the second inlet 16 that moves the cutting piston 18 against the elastic movement of the compression spring 19.

[0026] The cutting piston 18 has an end 18b having a recess or a reduced diameter, and preferably, the end forms part of the hydraulic cutting chamber 24 facing the bottom wall 20.

[0027] The cutting piston 18 has an intermediate portion 18a having a reduced diameter, and the intermediate portion 18a defines an axially extending annular gap 25 together with the cylindrical wall of the first internal cavity 14. The annular gap 25 is in the longitudinal direction between two sealing gaskets 26, 27 disposed on the cutting piston 18 and acting to make sliding contact with the first internal cavity 14.

[0028] One or two additional sealing gaskets 56, 57 that slide against the first internal cavity 14 are positioned on the cutting piston 18 at a longitudinal location between the port 23 of the branch passage 22 and the cutting chamber 24.

[0029] As explained below, the cut-off valve has the effect of preventing the rider from feeling the subsequent operation of the second control, as described in the introduction, when the first control is already activated.

[0030] The second internal cavity 15 houses, in the embodiments shown in Figures 3-8, at least one floating piston valve actuator 30, which is designed as a double piston having two longitudinally relative movable parts 31, 32, in an axially movable manner.

[0031] The second internal cavity 15 is in direct communication with a second outlet 17, which can be hydraulically connected to the vehicle's second brake (rear brake).

[0032] The cutting chamber 24 is hydraulically connected to the second internal cavity 15 through two longitudinally spaced inlet ports 28 and 29 for the operation of the second brake.

[0033] A compression spring 33 is provided in the second hydraulic chamber 15, which 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 a bottom wall 34 and, together with the side of the floating piston valve actuator 30 facing the bottom wall 34, forms a cavity 36 for operating the floating piston actuator 30. The passage 35 sets an annular gap 25 within the first internal cavity 14, which is in fluid communication with the hydraulic operating chamber 36 in the second internal cavity 15.

[0034] In the embodiments shown in Figures 3 to 8, the floating piston valve actuator 30 has a first internal or central piston element 31 and a second external piston element 32 that is coaxially mounted to the outside and is extendable and retractable and slidable on the first piston element 21.

[0035] The first piston element 31 has an end face 37 facing the bottom wall 34 of the second internal cavity 15. Preferably, the end face 37 forms a recess 38 or a portion with a reduced diameter that forms part of the hydraulic operating chamber 36.

[0036] The first piston element 31 has a large diameter base portion 39, a stem portion 41 that faces the base portion in the axial direction and has a smaller diameter than the base portion 39, or has a smaller lateral dimension, and an intermediate portion 40 that has an intermediate diameter between the base portion 39 and the stem portion 41. Two radial shoulder portions 42 and 43 are formed between the base portion, the intermediate portion, and the stem portion.

[0037] The base portion has at least one (two in this example) sealing gaskets 44, 45 that slide against the small-diameter portion 15a of the second internal cavity 15.

[0038] The second piston element 32 has a tubular shape overall, while its intermediate portion 40 and stem portion 41 of the first piston element 31 pass through it. The second piston element 32 forms a head 47 having a tubular portion 46 that is axially slidable to the axial intermediate portion 40 of the first piston element 31, and a sealing gasket 48 that slides against the small diameter portion 15b of the second internal cavity 15.

[0039] The double-diameter central passages 50 and 51 extend longitudinally through the second piston element 32 and have a laterally wider portion 50 and a laterally narrower portion 51 joined by a shoulder portion 52 (Figure 7).

[0040] The first and second piston elements are sealed together by a sliding seal element 49.

[0041] In the exemplary embodiments shown in Figures 3 to 8, the intermediate portion 40 of the first piston element has a sealing gasket 49 that slides against and acts on a cylindrical cavity 50 formed in the tubular portion 46 of the second piston element 32.

[0042] The working chamber 36 of the floating piston valve actuator 30 is hydraulically sealed to the second outlet 17 by sealing elements 44, 46, 48, and 49 which are collectively attached to the floating piston valve actuator 30.

[0043] In the embodiments described herein, in order to optimize the dimensions of the brake distributor, the two internal cavities 14, 15 are located parallel and adjacent to each other and each has piston elements that are biased parallel and in opposite directions.

[0044] The brake distributor has a resting position as shown in Figure 3. The cutting piston 18 is in a retracted and non-operating position with the spring 19 loosened. The cutting piston 18 abuts against the bottom wall 20 of the first cylindrical cavity 14, and the port 23 of the branch passage 22 is in fluid communication with the annular gap 25. The annular gap 25 is in fluid communication with the hydraulic chamber 36 through the passage 35. The floating piston valve element 30 is in a non-operating and retracted position. The compression spring 33 elastically biases the floating piston valve actuator 30 toward the bottom wall 34 of the second internal cavity 15, and the compression spring 33 biases the first piston element 31 toward the bottom wall 34 of the second internal cavity 15 by contact between the radial shoulders 42 and 52.

[0045] From the resting position in Figure 3, when the user activates the first brake control, the control sends brake fluid to the first inlet 11 of the brake distributor. The first portion of the incoming fluid passes directly through passages 13a and 13b to the first outlet 12 in order to directly activate the first brake. The second portion of the fluid flowing into the first outlet 11 passes through branch 22, through port 23, through the annular gap 25 around the cutting piston 18 without moving the cutting piston 18, and then reaches the base of the hydraulic chamber 36, pressing both of the two piston elements 31 and 32 to the right against the action of the compression spring 33 (Figure 4).

[0046] The forward motion of the piston elements 31 and 32 in response to the supply of brake fluid into the hydraulic operating chamber 36 reduces the volume available for the brake fluid in portion 15b of the second internal cavity 15 and also causes the pressurized brake fluid to be supplied from the second outlet 17 toward the second brake.

[0047] It should be noted that the brake fluid sent from the first control is separate from the brake fluid that reaches the second brake and does not reach the second brake. In fact, the brake fluid flowing into branch 22 remains contained in the hydraulic chamber 36 without reaching the second outlet 17.

[0048] Furthermore, it should be noted that the brake fluid passing through the first internal cavity does not cause the cutting piston 18 to move in the path from the branch passage 22 to the working chamber 36.

[0049] The fully extended positions of the two piston elements 31 and 32 (Figure 4) can be determined by longitudinally adjustable end stop elements 53, for example, by threaded joints 54. In the most extended position, the end of the stem portion 41 abuts against the end stop element 53.

[0050] In some embodiments, the distribution of braking can be selectively suppressed by adjusting the position of the end stop element 53 and advancing the end stop element 53 to a position where the floating annular piston element 30 is longitudinally blocked against the bottom wall 34 of the second internal cavity 15 (Figure 8). In this mode of operation, the introduction of brake fluid into the first inlet 11 causes the fluid to pass directly through the passage 13 to the first outlet 12 without having to move through the branch 22.

[0051] The rate at which brake fluid is supplied to the second brake can be adjusted by optionally choosing to create a second internal cavity 15 having two parts with different diameters. By dimensioning the second part 15b of the second internal cavity to have a larger diameter than the corresponding cavity diameter of the first part 15a that receives brake fluid from the first brake control, a predetermined amount of brake fluid is introduced into the left side 15a of the second hydraulic cavity, which in turn causes more brake fluid to flow out to the second brake from the right side of the second cavity and the wider part 15b as a result of the movement of the floating piston valve element 30. In other words, if less brake fluid is introduced upstream of the floating piston valve actuator 30, more brake fluid will move downstream of the piston valve actuator. The larger the diameter of the second part of the second cavity relative to the first part 15a, the stronger the braking force applied to the second brake as a result of the first brake control being activated.

[0052] In some embodiments not shown, the second internal cavity 15 may have a single diameter instead of the embodiments shown in Figures 3 to 8. In other different embodiments (not shown), the second internal cavity may have a smaller diameter in the second portion where the second outlet 17 opens, and a larger diameter in the first portion that receives brake fluid from the first inlet 11.

[0053] When the user activates only the second brake control, which activates the second brake (rear brake), the brake fluid introduced into the distributor through the second inlet 16 flows through the distributor and then to the second outlet toward the second brake. In particular, the brake fluid from the second inlet 16 reaches the cutting chamber 24 of the first internal cavity 14, moving the cutting piston from the resting position (Figure 3) to the operating position (Figure 5), and thus passes through the inlet port 28 into the portion 15b of the second internal cavity, and from there toward the second brake toward the second outlet 17. Sealing gaskets 56 and 57 provided on the cutting piston 18 prevent the brake fluid from the cutting chamber 24 from reaching the branch passage 22, and consequently the first outlet 12 and the first inlet 11. The cut-off valve eliminates fluid communication between the second inlet and the first outlet 12, thereby activating only the second brake control and not activating the first brake control, resulting in only the second brake being activated.

[0054] Furthermore, the sealing gaskets 56 and 57 of the cutting piston 18 prevent fluid from passing from the cutting chamber 24 to the first inlet 11, so the user will not feel the first control when only the second brake control is activated. Any operation of the first brake control while the user is still activating the second brake control will consequently send brake fluid only to the first outlet 12, directly from the first inlet 11 and through the passage 13 toward the first brake. However, since the gasket 27 (Figure 5) of the cutting piston 18 is located between the branch passage 22 and the passage 35 leading to the hydraulic chamber 36, it does not cause any further transmission of brake fluid to the second outlet.

[0055] Referring to Figures 6 and 7, the movement of the hydraulic distributor is typically described as first operating in a first brake control that primarily controls the front brakes, and then subsequently activating a second brake control. By activating the first control, fluid passes directly from the first inlet 11 to the first outlet 12, and this flow is partitioned. The flow is partially diverted through a branching passage 22, flows into an annular gap 25 around the cutting piston 18, and then through passage 35 to reach the hydraulic operating chamber 36 of the floating piston valve actuator 30.

[0056] The two inner and outer piston elements 31 and 32 of the floating piston valve actuator 30 move together to the right (Figure 6), while the inner piston element moves against the spring 33, causing a flow of a first amount of brake fluid contained within the second internal cavity 15 to the downstream side of the double piston, to the second brake. The compression spring 33 is compressed only partially. Therefore, in this first braking phase, the second brake is actuated only by the first control. Note that (Figure 6) the downstream (rightward) movement of the floating piston valve actuator 30 causes the gasket 48 of the outer piston element 31 to cross the two communication ports 28 and 29, thereby preventing the brake fluid from passing directly from the cutting chamber 24 to the second outlet 17.

[0057] When the user also activates the second control (Figure 7), the caliper of the second brake receives an additional pressure pulse, as described below, and the braking force acting on the second brake increases. The brake fluid introduced from the second inlet 16 reaches the cutting chamber 24 of the first internal cavity 14, moving the cutting piston 18 from the resting position (Figure 6) to the operating position (Figure 7). The gaskets 56 and 57 of the cutting piston 18 are positioned longitudinally between the cutting chamber 24 and the branch passage 22, and as a result, the first inlet 11 and the first control upstream thereof are not affected by the pressurization in the cutting chamber 24. Consequently, the user does not feel the operation of the second control, which operates after the first control has been activated, while the first control is already operating.

[0058] The brake fluid passes from the cutting chamber 24 through the communication ports 28 and 29 into and around the second internal cavity 15 upstream of the gasket 48 of the outer piston 32, thereby causing further movement of the second outer piston element 32 sliding over the first piston element 31 in a telescopic manner, compressing the spring 33, and causing a further increase in the pressure of the brake fluid toward the second outlet 17 and the second brake. This provides an additional braking force acting on the second brake in addition to the braking force already acting and being enforced by the operation of the first control.

[0059] When the user activates the second brake control instead of the second, and subsequently activates the first brake control simultaneously with the second brake control, the distributor separates the two brake actions according to the non-combined braking mode. The braking action resulting from the activation of the second control directly supplies brake fluid to the second brake from the second inlet 16 to the second outlet 17, affecting the brake fluid passing through the cutting chamber 24 and the portion 15b of the second hydraulic cavity downstream of the floating piston valve actuator 30. The pressurization of the cutting chamber 24 moves the cutting piston 18 to the left, and subsequently closes the branch passage 22. Thus, the subsequent pressurized brake fluid flow to the first inlet 11 directly passes the fluid from the first inlet 11 through the passage 13 to the first outlet 12, according to the braking mode independent of the activation of the second control.

[0060] In an alternative embodiment, as shown in Figures 9 to 11, the floating piston valve actuator 30 consists of a single piston element. This element performs a first forward movement as a result of expansion of the hydraulic chamber 36 when the user activates the first brake control (Figure 10), and a second additional forward movement (Figure 11) when the user also activates the second brake control.

[0061] As can be understood, the braking action of a second brake (e.g., the rear brake) resulting from acting on the second control may be imperceptible to the user operating the first control because the action of the cut-off valve allows only a direct flow from the first inlet to the first outlet.

[0062] It should be noted that the connections shown herein as the first inlet and the first outlet may be connected interchangeably, as described for the first brake control and the first brake, respectively, or vice versa.

[0063] Furthermore, according to the alternative operating mode described above, where the first brake is the front brake and also an independent brake, the connections of the distributor may be reversed. According to this alternative mode of connection, the first outlet is hydraulically connected to the rear brake, and the second outlet is connected to the front brake. As a result, when the first control is activated, the distributor brakes only the rear wheel, and when the second control is activated, it brakes both the front and rear wheels in combination, and in this operating mode, the rear wheel is an independent wheel.

[0064] Various forms and embodiments of the brake distributor will be described, and it will be understood that each embodiment can be combined with any other embodiment. Furthermore, the details of the embodiments and configurations may be broadly modified as defined in the claims, as non-limiting examples, from those purely described and illustrated.

Claims

1. At least one first inlet (11) that can be hydraulically connected to the first brake control of the vehicle, At least one second inlet (16) that can be hydraulically connected to the vehicle's second brake control, A first outlet (12) that can be hydraulically connected to the first brake of the vehicle, A second outlet (17) that can be hydraulically connected to the second brake of the vehicle, the second outlet (17) is in direct communication with the second internal cavity (15), A first passage (13) that sets the first inlet (11) and the first outlet (12) into direct fluid communication, A branch passage (22) is provided for fluid communication with the first internal cavity (14), and the first passage (13) is set up for the branch passage (22), Disconnecting valves (14, 18, 24) are located within the first internal cavity (14) and operate in response to the brake fluid supplied to the second inlet (16), and block fluid communication from the first passage (13) to the first internal cavity (14) through the branch passage (22). A hydraulic brake distributor.

2. A hydraulic brake distributor according to claim 1, The first internal cavity (14) has an end that extends in the longitudinal direction and forms a hydraulic cutting chamber (24) that is hydraulically connected to the second inlet (16), A floating cutting piston (18) is received longitudinally within the first internal cavity (14) and elastically biased toward the cutting chamber (24), A longitudinally extending second internal cavity (15) communicating with the first internal cavity via at least two internal passages (28, 35), the second internal cavity (15) having a first end forming a hydraulic working chamber (36) that is hydraulically connected to the first internal cavity (14) via the first internal passage (35), and a second end that is hydraulically connected to a second outlet (17), At least one second communication passage (28, 29) for communication between the internal passages, providing fluid communication between the cutting chamber (24) and the second internal cavity (15), and opening into the second internal cavity (15) at a position midway in the longitudinal direction between the first internal passage (35) and the second outlet (17), At least one floating piston valve element (30) within the second internal cavity (15) is elastically biased toward the hydraulic working chamber (36), It has, The aforementioned cutting piston (18) A passive position that allows fluid to communicate with the hydraulic operating chamber (36) through the first internal cavity (14) between the branch passage (22) and the first passage (35), and The cutting chamber (24) is pressurized by the brake fluid supplied to the second inlet (16), and the cutting piston (18) is in an operating position that closes the branch passage (22). It has, The piston valve element (30) is The working chamber (36) is not pressurized, and the piston valve element (30) is in a passive position that allows fluid communication from the communication passage (28) from the cutting chamber (24) to the second output (17) through the second internal cavity (15), and It has, In response to the pressurization of the hydraulic operating chamber (36), the position of the sealing element (48) of the piston valve element (30) that slides against the second internal cavity (15) is located at an intermediate longitudinal position between the communication passage (28) and the second outlet (17), the sealing element (48) does not allow direct fluid communication from the communication passage (28) from the cutting chamber (24) to the second outlet (17) through the second internal cavity (15), and the pressurization of the cutting chamber (24) can further move at least a portion of the piston valve element (30) toward the second outlet (17). Hydraulic brake distributor.

3. In the hydraulic brake distributor according to claim 2, The cutting piston (18) is positioned between two sealing gaskets (26a) that slide against the first internal cavity (14) and has a reduced diameter intermediate portion (18a) which, together with the first internal cavity (14), defines an axially extending annular gap (25) that is in fluid communication with the first passage (35) and the branch passage (22) at the passive position of the cutting piston (18). Hydraulic brake distributor.

4. In the hydraulic brake distributor according to claim 2 or claim 3, The cutting piston (18) has a recess or a reduced diameter end (18b), the end facing the bottom wall (20) of the first internal cavity (14) and forming part of the hydraulic cutting chamber (14). Hydraulic brake distributor.

5. In the hydraulic brake distributor according to claim 2, The cutting piston (18) operates in sliding contact with the first internal cavity (14) and has at least one sealing gasket (56, 57) positioned on the cutting piston (18) at at least one intermediate position in the longitudinal direction between the cutting chamber (24) and the port (23) through which the branch passage (22) opens. Hydraulic brake distributor.

6. In the hydraulic brake distributor according to claim 2, The cutting chamber (24) is hydraulically connected to the second internal cavity (15) through two longitudinally spaced communication passages (28, 29). Hydraulic brake distributor.

7. In the hydraulic brake distributor according to claim 2, The second internal cavity (15) is a double-diameter cylindrical cavity having a portion with a smaller diameter (15a) and a portion with a larger diameter (15b). Hydraulic brake distributor.

8. In the hydraulic brake distributor according to claim 1, The floating piston valve actuator (30) is Designed as two parts (31, 32) that can move relative to each other in the longitudinal direction, First radially inward, or central piston element (31), A second radially outward piston element (32) is arranged coaxially and in a telescopic manner on the first piston element (31), and The first piston element (31) and the second piston element (32) have at least one sliding contact sealing element (49) that performs a sliding contact sealing action between them. Hydraulic brake distributor.

9. In the hydraulic brake distributor according to claim 8, The first piston element (31) has a recess (38) or an end face (37) that forms a piston with a reduced diameter, and the end face faces the bottom wall (34) of the second internal cavity (15). The aforementioned recess or the end portion (38) having a reduced diameter defines a part of the hydraulic operating chamber (36). Hydraulic brake distributor.

10. In the hydraulic brake distributor according to claim 8, The first piston element (31) has a base (39) having a large diameter, a stem (41) facing the base (39) in the longitudinal direction and having a smaller diameter or lateral dimension than the base (39), and an intermediate portion (40) having an intermediate diameter between the base (39) and the stem (41). Hydraulic brake distributor.

11. In the hydraulic brake distributor according to claim 10, The base (39) of the first piston element (31) has at least one sealing gasket (44, 45) that slides against the second internal cavity (15). Hydraulic brake distributor.

12. In the hydraulic brake distributor according to claim 10, The second piston element (32) has an overall cylindrical shape into which the intermediate portion (40) and the stem portion (41) of the first piston element (31) are inserted and pass through. Hydraulic brake distributor.

13. In the hydraulic brake distributor according to claim 10, The second piston element (32) has a tubular portion (46) that is axially slidable in the axial intermediate portion (40) of the first piston element (31), and a head (47) having the sealing element (48) that slides against and acts in contact with the second internal cavity (15). Hydraulic brake distributor.

14. In the hydraulic brake distributor according to claim 10, The second piston element (32) extends longitudinally through the second piston element (32) and has a double-diameter central passage (50, 51) having a wide portion (50) and a narrow portion (51) joined by a shoulder portion (52). Hydraulic brake distributor.

15. In the hydraulic brake distributor according to claim 10, The intermediate portion (40) of the first piston element (31) supports the sealing element (49) which slides against and acts upon the wide portion (50) of the double-diameter central passage of the second piston element (32). Hydraulic brake distributor.

16. In the hydraulic brake distributor according to claim 8, The compression spring (33) biases the second piston element (32) longitudinally toward the first piston element (31) and toward the hydraulic operating chamber (36). Hydraulic brake distributor.

17. In the hydraulic brake distributor according to claim 2, The floating piston valve actuator (30) is The sealing element (48) acts in sliding contact with the second internal cavity (15) and is located at an intermediate longitudinal position between the communication passage (28) and the second outlet (17) at the position where it extends at least partially, At one end of the piston valve actuator (30) adjacent to the hydraulic operating chamber (36), at least one additional sealing gasket (44, 45) acts in sliding contact with the second internal cavity (15), It consists of a single piston element (31) having Hydraulic brake distributor.

18. In the hydraulic brake distributor according to claim 2, The two internal cavities (14, 15) are parallel and continuous. Hydraulic brake distributor.

19. In the hydraulic brake distributor according to claim 18, The cutting piston (18) of the first internal cavity (14) is biased in a first direction, and the piston valve element (30) of the second internal cavity (15) is biased in a second direction parallel to and opposite to the first direction. Hydraulic brake distributor.

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