Abstract: The hub (2) of the booster piston of the brake booster, in which the valve plunger (5) slides, comprises two opposite radial cavities (18), the stop key (15) of the plunger being formed from metal wire and comprising two facing stop portions (16) which are joined by an intermediate arch (17) and which are each housed in a central housing portion (20) of the corresponding radial cavity, each stop portion (16) being extended by an end portion (26) which comes to bear against a corresponding bearing surface (23) of the radial cavity (18).

Abstract: Hydraulic assistance device comprising a housing (10) provided with a bore (12) in which a piston mechanism (30, 42) is slidably mounted, which mechanism is displaceable by a brake pedal between a first position linking a first chamber (38, 56), connected to a brake circuit (60), with a low-pressure reservoir and isolating this chamber (38, 56) from a high-pressure fluid source (66), and a second position isolating the chamber (38, 56) from the low-pressure reservoir and linking it with the high-pressure source (66), the piston mechanism (30, 42) being displaceable by the brake pedal in the event of failure of the high-pressure circuit (66) thereby producing pressure increase in a second chamber (69) connected to the brake circuit (60), characterized in that the working area of the piston mechanism (30, 42) is equal to the cross-section of the bore (12).

Abstract: The tubular part (9) of the hub (7) of the piston assembly (5), which encloses the distribution valve (8), supports an assembly (200) consisting of a guiding ring (21) and a seal (20) cooperating with the internal wall of a tubular part (22) mounted, for example crimped, inside a central duct (23) of the rear shell (2) of the servomotor housing (1) and having a first end part (26) extending so as to project axially into the rear working chamber (4) of the servomotor. Advantageously, the tubular part (22) has a second end part (37) forming a stop (36) for a limit member (31) associated with input rod (12) and forming a bearing for the return spring (30) of the input rod (12).

Abstract: The strut, mounted in the vicinity of the brake application mechanism and bearing with each of its ends against each of the shoes (3, 4), has a device which automatially extends according to the wear of the friction components and which consists of a nut-and-bolt system (8-11) operated by a pawl (12) engaging with teeth (11) integral with the nut. The pawl (12) is mounted on an elastic leaf (13) integral with the strut and separated elastically therefrom by a rocker lever (14) which, by tilting, allows the leaf (13) to move toward the strut when the shoes are pushed apart, thus enabling the pawl (12) to cause the nut (11) to rotate and, therefore, the length of the strut to increase. A bimetallic strip (30) is capable of counteracting the tilting movement of the lever (14) when the brake is hot.

Abstract: Control device (10) for a twin master cylinder (18) of the type with two master cylinders situated side by side and parallel to one another; the device (10) is capable of being positioned between an actuating pedal (12) and pistons (26, 26') of the master cylinders. According to the invention the device (10) incorporates a compensation (63, 63') of the travel of a control rod (52) situated on the same side as the pedal (12) relative to the travel of two independent push rods (34, 36') which are capable of acting upon each of the pistons (26, 26').

Abstract: Two pressure disks (13, 19) are arranged in tandem between the valve plunger (9) and the rear end (21) of the booster output rod (22), a stepped middle member (23), having a front portion with a reduced diameter (24) sliding inside an annular spacer member (17), being arranged between the two pressure disks and cooperating with the latter.

Abstract: The servomotor, of the type incorporating an abutment component (7, 70) which is mounted on the input rod (6) and which cooperates in bearing, in the rest position of the servomotor, against a stop structure (9, 12) which is firmly fixed to the casing, incorporates in the stop structure an electrical contact mechanism (13, 15) which is capable of being actuated by the abutment component (7, 70) and which advantageously incorporates and actuating portion (17) which is interposed between the abutment component (7, 70) and an internal bearing surface (20) of an end collar portion (12) of the stop structure which carries the fixed electrical contacts (13).

Abstract: Deceleration-responsive braking corrector for the brake system of a vehicle, comprising a body having a chamber, an inlet which is connected to the chamber and intended to be connected to a pressurized fluid source, and outlet which is connected to the chamber and is intended to be connected to the brakes of the vehicle, characterized in that it comprises a mass which is slidably mounted inside the chamber and is movable in response to the deceleration of the vehicle, a piston pushing the mass toward a rest position and forming a closure element for a shut-off valve, and a by-pass having a restriction which bypasses the shut-off valve and can be sealed off by the mass when the latter moves in response to a deceleration.

Abstract: The invention relates to a brake actuator with automatic adjustment of the type including a screw and nut actuating mechanism (32) the lengthening of which is controlled by a combined system with a screw and nut of reversible pitch and a unidirectional clutch (42) which is responsive to the relative axial movement between a control piston (14) and a fixed body (10) housing the control piston (14). The brake actuator includes a device for controlling (62) the rotation of the nut (34) of the actuating mechanism (32) so as to allow rotation of the nut (34) beyond a predetermined value of torque for rotating the latter.

Abstract: In a branch hydraulic line (6.sub.a, 6.sub.b) upstream of the distribution servovalve (1) of the assisted steering system, a valve mechanism with electromagnetic control (10) is situated, which comprises a valve member biased by an electromagnetic actuator (16) having two states, energized and unenergized, which is controlled by a switch (20.sub.a, 20.sub.b) actuable by the lever (21) of the gear changing mechanism of the vehicle so as to close the branch line (6.sub.a, 6.sub.b) during engagement of the parking gears (first and reverse) and thus to obtain maximum hydraulic assistance power, the assistance power being reduced during other conditions of use (driving along the road) of the vehicle.

Abstract: The support (14) for the resilient valve member (2) of the distribution valve assembly has an internal end zone (26) extending radially in the vicinity of the front annular active part (4) of the valve member (2) and forming, at the front, a bearing surface for an elastic washer (32) constituting the valve spring and, at the rear, a bearing surface for the return spring (28) of the booster input rod (8). The internal end zone (26) advantageously consists of a front part (15) for supporting the valve member, which part is mounted on a channel (19; 20; 21) receiving the external mounting part (13) of the valve member (2) and formed by a rear part (16) of the valve member support, which part is mounted in the rear end (17) of the tubular hub (1).

Abstract: In a bridging circuit (6.sub.a, 6.sub.b) connecting the two opposing chambers ( V.sub.1 V.sub.2) of the hydraulic assistance actuator (5), a valve seat (11) is interposed which may be closed selectively by a valve member which is biased by an electromagnetic actuator (14) having two states, energized and unenergized, which is controlled by at least one switch (18.sub.a, 18.sub.b) actuatable by the lever (19) of the gear changing mechanism of the vehicle so as to close the bridging circuit (6.sub.a, 6.sub.b) when the parking gears are engaged (first and reverse) in order to obtain maximum hydraulic assistance power, the assistance power being reduced during other conditions of use of the vehicle (driving along the road).

Abstract: Hydraulic assistance device, incorporating a casing (10) provided with a bore (12) in which first piston means (16, 18) is slideably mounted, the piston (16, 18) being able to move under the effect of the actuation of a brake pedal between a first position allowing communication between a first chamber (72) which is connected to a braking circuit (70) and a low pressure reservoir (40), and isolating this chamber (72) from a source of high pressure fluid (76), and a second position isolating the chamber (72) from the low pressure reservoir (40) and causing it to communicate with the high pressure source (76), the device also incorporating a second chamber (38) formed in the casing (10), the communication between the first chamber (72) and the reservoir (40) incorporating a second bore (52) in which a control piston (54) of second piston means (54, 60) is slideably mounted, incorporating a bore (56), the first piston having a bore in which a plunger (31) is slideably mounted, the plunger (31) joining the first

Abstract: The invention relates to spring (40) for a disc brake. The spring is mounted elastically in an opening (68) of a caliper and exerts on the support plates (26, 28) a radial force (F1) as well as a tangential force (F'5) ensuring that the plates assume a preferred lateral position. The spring (40) comprises a metal leaf with two main arms (42, 44) connected to each other and to a central arm (48) by a main fold (46), the spring having the general shape of a "trident", the end prongs of which comprise the main arms (42, 44), the latter cooperating by way of their free ends (50) with a surface (52) formed on the caliper (10) and by way of central portions (54) with bearing surfaces (56) formed on the support plates, the central arm (48) having at its free end (62) a Z-shaped fold cooperating with two surfaces (64, 66) of the caliper, the main fold (46) having a lug (74) cooperating radially with another surface (76) of the caliper (10).

Abstract: The invention concerns a thrust plate spring for a disc brake with a caliper (10) sliding on a fixed support (12) comprising a first friction component (14) which is capable of being applied to one surface of a brake disc by means of a brake actuator through a thrust plate (34), and a second friction component which is capable of being applied to the other surface of the disc through the sliding caliper. According to the invention, the spring (64) comprises an elongated metal leaf which is fixed to the thrust plate (34) and which co-operates with an external peripheral portion (80) of the caliper (10) pushing the plate (34) radially outwards by bearing radially against the corresponding surfaces (50) associated with the fixed support (12).

Abstract: Control device (10) for a twin master cylinder (18) of the type with two master cylinders situated side by side and parallel to each another; the device (10) being capable of being positioned between an actuating pedal (12) and pistons (26, 26') of the master cylinders. According to the invention the device (10) incorporates a twin beam (36) ensuring balancing of the forces applied to each of the pistons (26, 26') while ensuring the rigidity of the control device (10), and the twin beam (36) incorporates a device for maintaining the separation of the points of application (32, 32') of the forces on the pistons (26, 26').

Abstract: The invention relates to a disc brake with automatic adjustment, of the type incorporating a calliper (10), a brake actuator (12) which is adapted to act directly upon a first friction component (14) and, by reaction through the calliper (10) upon a second friction component (16). The brake actuator (12) incorporates a mechanical control (32) acting upon a hydraulic control piston (20) through an automatic adjustment device, the latter being formed by a screw and nut device (46, 60) with reversible pitch which is actuatable by the hydraulic piston (20) beyond a predetermined travel of the latter which is defined by a clearance between an annular component (82) and a thrust bearing (92) which is adapted to act upon the screw and nut device (46, 60), the clearance being capable of varying as a function of the pressure applied to the control piston (20).

Abstract: The device for controlling flow (10) situated in a branch hydraulic line (6), comprises a piston slide (15) sliding a bore (14) into which an inlet passage (36) and an outlet passage (20, 21) open, the slide forming with the outlet passage (21) a modulable restriction (s); the device comprsies a fluid passage between the inlet and outlet passages which includes a first portion (32, 33, 34), formed in the slide (15), and a second portion (19, 24, 23, 22) which is formed in the body (13) and is closed selectively by a spring biased (27) valve member (26) and the plunger (28) of an electromagnetic control member (9) piloted by an electrical signal which is a function of a significant parameter, for example the speed of a vehicle for the assisted steering of a vehicle.

Abstract: The planar abutment key (11) incorporates in its body portion (18) two flexible fingers (22) extending laterally and angularly in the direction away from the end portion (19) of the key which forms abutment arms (21) for the plunger, each finger (22) ending in a sharp angle (24), the transverse distance at rest between the sharp angles (24) being greater than the transverse width (d.sub.1) of the slot (12) in the hub portion of the assistance piston (1) in which the key (11) is housed.

Abstract: The servo device for controlling flow (10) situated in a branch hydraulic line (6), incorporates in a body (11) an inlet passage (12) and an outlet passage (9) connected by an intermediate passage (13) forming a seat (14) for a valve component (15) which is pushed against its seat by a spring (26) and by an electromagnetic actuator (16) via a push-rod (23) which is slidingly sealingly mounted in a bore (22) between the intermediate passage (13) and an internal chamber (19) which is connected to the inlet passage (12).