Abstract: This invention relates to a master cylinder (10), inside a bore (14) of which two axial primary and secondary pistons (16, 18), are slidingly fitted, and in which at least one sealing means (48, 50) is disposed in contact with each piston, defining a supply chamber (56, 60) and a pressure chamber (58, 62). Each piston (16, 18) comprises a bore (78, 80), open in the direction of the front pressure chamber (58, 62), and the piston (18) comprises a valve-forming through-hole (88), opening into its periphery and into its bore (80), in order to isolate the front pressure chamber when it passes beyond the sealing means so as to produce a braking pressure, characterised in that the front pressure chamber (62) associated with at least one piston (18) comprises at least one tubular cylindrical element (90) extending axially outside the piston (18) and rearwards of the sealing means (50) for the obturation of the through-hole (88) according to a reduced stroke (Cm2).

Abstract: This invention relates to a master cylinder of the so-called “penetration” type, in which a cup (3), which is fitted inside a groove (11) of the master cylinder, bears on the wall (20) of a piston (2) in a sealing manner, and in which such wall (20) is provided with main resupply ports (51). According to the invention, the wall (20) of the piston (2) also comprises secondary resupply ports (52) having a smaller size than that of the main resupply ports (51) and disposed farther from the bottom part (33) of the cup (3), and achieving an outstanding static resupply of the master cylinder with brake fluid, with a reduced dynamic dead stroke.

Abstract: The invention relates to a brake control device comprising: a liquid reservoir (4), a master cylinder (2), and a valve (14) able to allow the liquid of the cylinder in the reservoir to rise by offering a first minimum flow cross section (31). The valve is able to allow the rise by offering a second minimum flow cross section (33) which is larger than the first cross section when a pressure in the cylinder exceeds a given threshold.

Abstract: This invention relates to a master cylinder (10), inside a bore (14) of which two axial primary and secondary pistons (16, 18), are slidingly fitted, and in which at least one sealing means (48, 50) is disposed in contact with each piston, defining a supply chamber (56, 60) and a pressure chamber (58, 62). Each piston (16, 18) comprises a bore (78, 80), open in the direction of the front pressure chamber (58, 62), and the piston (18) comprises a valve-forming through-hole (88), opening into its periphery and into its bore (80), in order to isolate the front pressure chamber when it passes beyond the sealing means so as to produce a braking pressure, characterised in that the front pressure chamber (62) associated with at least one piston (18) comprises at least one tubular cylindrical element (90) extending axially outside the piston (18) and rearwards of the sealing means (50) for the obturation of the through-hole (88) according to a reduced stroke (Cm2).

Abstract: Hydraulic master cylinder for a motor vehicle braking circuit, comprising means for concealing the dead travel of the primary (16) and secondary (44) pistons, these concealing means consisting of additional valve shutters (80) borne by the valve shutters (26, 56) that shut off the axial passages (22, 58) formed in the primary (16) and secondary (44) pistons, these additional valve shutters allowing the pressure in the primary (18) and secondary (52) chambers to increase right from the start of movement of said pistons over their dead travels.

Abstract: Hydraulic master cylinder for a motor vehicle braking circuit, comprising means for concealing the dead travel of the primary (16) and secondary (44) pistons, these concealing means consisting of additional valve shutters (80) borne by the valve shutters (26, 56) that shut off the axial passages (22, 58) formed in the primary (16) and secondary (44) pistons, these additional valve shutters allowing the pressure in the primary (18) and secondary (52) chambers to increase right from the start of movement of said pistons over their dead travels.

Abstract: A hydraulic brake circuit is intended for a motor vehicle provided at least with an electrically pilot-controlled braking function, and including at least a master cylinder (1), an electric pump (2), first and second brake motors (3, 4), first and second respective solenoid valves (5, 6), and a low-pressure capacity (7). In addition to a conventional accumulation chamber (8), the capacity (7) comprises an access chamber (13) which interacts with the accumulation chamber (8) to form a simplified distributor which offers additional switching options which can be used for a new braking function.

Abstract: An automatic braking device for a vehicle equipped with at least one fluid circuit connecting a master cylinder (10) to a consumer circuit including at least one brake motor and possessing, furthermore, a pump (30) capable of delivering to the consumer circuit, via a non-return valve (31), fluid under high pressure taken from the master cylinder (10) comprises, in combination, a proportional solenoid valve connected to the consumer circuit and having a regulating outlet (20), during operation in the solenoid valve regulating the pressure of the fluid in the consumer circuit in relation to that of the fluid in the feed circuit of the pump, and a regulating slide (16) arranged between the master cylinder and the feed circuit of the pump in order to regulate the pressure of the fluid in the latter circuit and determine a reference pressure for the solenoid valve.

Abstract: The control circuit of a double-acting hydraulic jack (10), consisting of a piston (12) connected to an output rod (18) and separating a cylinder into two chambers (14, 16), comprises a source of fluid under pressure (20, 26), a distribution system (28, 28', 52, 52') alternately putting one of the chambers, or control chamber, in communication with the source of fluid under pressure (20, 26) and the other chamber, or controlled chamber, in communication with a reservoir of fluid under low pressure (25), in order to control the movement of the piston (12) of the jack (10). The jack comprises an auxiliary circuit (50, 120, 122) for preventing communication between the controlled chamber and the reservoir (25), interrupting communication between the control chamber and the source of fluid under pressure (20, 26) and allowing communication between the controlled and control chambers when the pressure of the fluid in the controlled chamber exceeds a predetermined value.

Abstract: The braking system comprises two hydaulic sub-circuits each connecting a driving wheel and a free wheel to a working chamber of a master cylinder (1) and includes a wheel braking anti-lock device comprising, for each of the wheels, a three-way solenoid valve (54, 53, 52, 51) normally opening communication between an inlet of fluid under pressure and the brake motor (34, 33, 32, 31) associated with the wheel, while, in the expansion phase of the anti-lock device, it closes this communication and connects the brake motor to a reservoir (21, 22) of fluid under low prressure for each sub-circuit, a switching slide (11, 12) isolating the brake motors from the working chamber of the master cylinder during the functioning of the pump (46, 45) is associated with the anti-lock device.

Abstract: The invention relates to an integrated pressure amplification and modulation system for a hydraulic brake circuit, comprising at least one master cylinder (10), a hydraulic motor, a source of fluid under high pressure (48) and a reservoir of fluid under low pressure (14), a computer-controlled solenoid (32) modulating by way of a magnetic core (30) the position of a slide (22) which slides in a bore (20). According to the invention, the fluid under pressure coming from the master cylinder (10) is applied to one face (24) of the slide (22), the other face of which bears on the magnetic core (30l ) and receives the force exerted by a spring (34) for return to rest. A reaction chamber (40) formed in the slide (22) is connected permanently to the hydraulic motor (38), and the hydraulic motor (38) is connected either to the reservoir (14) or to the source of fluid under pressure (48), depending on the position of the slide (22).

Abstract: A hydraulic pump comprises at least one alternating-cycle piston (20) having a suction phase and a delivery phase, and sliding in a fixed cylinder (22). The pump possesses in addition a nonreturn suction valve (32) placed between a source of fluid under low pressure (28) and a working chamber (30) defined in the cylinder, and a nonreturn delivery valve (34) placed between the working chamber (30) and an output chamber (16) for the fluid under high pressure, connected to an application circuit 10, 12). The output chamber (16) possesses a wall (40) which is movable as a function of the pressure which prevails in the output chamber (16), the movable wall (40) being capable of controlling the locking of the delivery valve (34) in an open position substantially during the greater part of the suction phase when the pressure in the output chamber (16) is greater than a given pressure, in such a way that the suction valve (32) stays closed in a corresponding manner.

Abstract: A hydraulic pump comprises at least one reciprocating piston (2) sliding in a stationary cylinder (4), a non-return suction valve (12) arranged between a source of fluid under low pressure and a working chamber (10) defined in the cylinder (4), and a first non-return delivery valve (16) arranged between the working chamber (10) and an outlet chamber (14) for the fluid under high pressure. A conduit (24) connects the outlet chamber (14) and the working chamber (10), the piston (2) leaving this conduit (24) open at the end of the suction period and at the start of the delivery period and closing it during the rest of the cycle.

Abstract: The hydraulic pump comprises at least one reciprocating piston (2) sliding in a stationary cylinder (4). The piston (2) comprises, on the same side as the working chamber (10), a cylindrical skirt (22) which has the inside diameter of the cylinder (4) and in which is made at least one first port (18) putting the working chamber (10) in communication with the outer wall of the skirt (22). A second port (24) puts the duct (6) upstream of the valve (12) in communication with the outer wall of the piston (2). Finally, a slot (20) of a length at least equal to the distance separating the ports (18, 24) is made in the cylinder (4) so as to cause these ports (18, 24) to communicate over a specific zone of the reciprocating movement of the piston when the piston is sensibly at mid-stroke.