Abstract: A servobrake (10) including a pneumatic brake booster (12) and a master cylinder (22) with a main piston (20) that slides in a front pressure chamber (24). The main piston (20) has a fixed first rear end (46) acted on by a pneumatic piston (16) of the booster (12) and a moving second rear end (48) acted on by a feeler (18) of the booster (12) that is a coaxial with the piston (16) and acts upon a reaction ram (52) to communicate pressure forces in a front pressure chamber (24) of the master cylinder to the second end (48). A hydraulic isolation valve shutter (58), independent of the internal piston (50) of the ram (52), is activated when the input force of the booster (12) exceeds a given rate threshold so that the braking force is not reduced.

Abstract: A pneumatic brake booster with reduced dead travel comprising a skirt (10) which can move in a sealed manner in a casing, delimiting a low-pressure chamber and a variable-pressure chamber, with respect to a pneumatic piston (16) over a certain travel. The displacement of the pneumatic piston being controlled by the skirt in a first direction when the skirt comes into contact with a first face of an annular plate (100) which is arranged in the low-pressure chamber and is fastened rigidly to the pneumatic piston, and the displacement of the piston in a second direction is controlled by an elastic means mounted in the low-pressure chamber and bearing by one of its ends on a second face of the annular plate (100).

Abstract: A braking device, particularly for a motor vehicle, comprising a master cylinder (10) associated with a pneumatic booster (12), and a vacuum pump (36) to create a vacuum in the vacuum chamber (16) of the booster, characterized in that the vacuum pump (36) is fixed to the envelope (14) of the booster on the inside of the latter within the vacuum chamber (16).

Abstract: A master cylinder (10) having an axial body (12) with a bore (14) for receving a piston (16, 18), a front seal (26, 28) and a rear seal (30, 32) to delimit a rear supply chamber (34, 38) from a front pressure chamber (36, 40). A supply duct (42, 48) in the body (12) that connects a reservoir to the rear supply chamber (34, 38) has an opening between the front seal (26, 28) and the rear seal (26, 28). The front seal (26, 28) is mounted in a groove (110, 112) of the body (12) and has an interior lip that contacts the piston (16, 18) and lifts off the piston (16, 18) as the piston (16, 18) returns from a position of application to a position of rest to allow hydraulic fluid to be resupply the front pressure chamber (36, 40).

Abstract: The invention provides a braking pneumatic servomotor (10), of the type comprising a moving piston (22) biasing an actuating rod (34) for a master cylinder (28) as a result of the actuation of a plunger (56), a front face of which traverses the piston (22), constitutes a first finger (62) and, when the plunger (56) is in the end actuation position, is capable of penetrating a reaction disk (44) interposed between the piston (22) and the actuating rod (34), so as to transmit the reaction force from the master cylinder (28) to the plunger (56), characterised in that it comprises a second finger (68) which, when the control rod (46) is actuated at a higher speed than a determined speed, is capable of being locked by a unidirectional clutch device (70) in an axial position, which is determined in relation to the piston (22), and then of being driven by the piston so as to cause the second finger (68) to penetrate the reaction disk (44), in order to enable the first finger (52) to apply a braking force more quickl

Abstract: A pneumatic brake booster (10) of the type comprising a moving piston (22) urging an actuating rod (34) of a master cylinder (28) in response to actuation of a plunger (56) of which a front end, passing through the piston (22) and forming a first feeler (62) can, when the plunger (56) is in the extreme position, penetrate a reaction disc (44) inserted between the piston (22) and the actuating rod (34) to transmit to the plunger (56) the reaction force of the master cylinder (28), characterized in that it comprises a second feeler (68) which can, when the control rod (46) is actuated at a rate higher than a determined rate, be pushed by the plunger (56) and immobilized by a one-way engagement device (70) in an axial position that varies with respect to the piston (22), then be driven by the piston to push the second feeler (68) into the disc (44) so that the first feeler (52) applies a braking force more rapidly.

Abstract: A pneumatic brake booster, particularly for a motor vehicle, comprising a feeler (42) mounted to slide along a plunger (32) at the end of a control rod (22), and pivoting key (62) immobilizing means axially blocking the feeler (42) with respect to the plunger under normal braking and unblocking it under emergency braking so as to reduce the length of the plunger-feeler assembly and thus increase the jump phase.

Abstract: A brake master cylinder having a bore with a front portion for receiving and guiding a piston and arranged forward of a front sealing arrangement. The sealing arrangement includes at least one groove that establishes communication between a front chamber and a reservoir to allow, as the piston retreats towards its position of rest, the resupply of fluid through a radial supply duct from the reservoir.

Abstract: The present invention relates mainly to a reaction device for a pneumatic brake booster with modifiable boost and to a brake booster comprising such a device.

Abstract: Brake master cylinder (10) for a motor vehicle, of the type which comprises an essentially axial body (12) inside a bore (14) of which is slideably mounted at least one axial piston (16, 18), of the type in which the bore (14) comprises two sealing means, front (26, 28) and rear (30, 32), interposed between the piston (16, 18) and the bore (14), the front sealing means (26, 28) delimiting, in the bore (14), rear supply (34, 38) and front (36, 40) chambers, of the type in which the body (12) comprises a supply duct (42, 48) which connects an external reservoir to the rear supply chamber (34, 38) and which opens between the two sealing means (26, 28, 30, 32), characterized in that the front sealing means (26, 28) comprises a front seal (26, 28) which is mounted in a groove (110, 112) of the body (12), and of which an interior lip, arranged in contact with the piston (16, 18), is capable of lifting off the piston (16, 18) when it returns from a position of application to a position of rest to resupply the front

Abstract: A braking device, particularly for a motor vehicle, comprising a master cylinder (10) associated with a pneumatic booster (12), and a vacuum pump (36) to create a vacuum in the vacuum chamber (16) of the booster, characterized in that the vacuum pump (36) is fixed to the envelope (14) of the booster on the inside of the latter within the vacuum chamber (16).

Abstract: A servobrake (10), of the type comprising a pneumatic brake booster (12) and a master cylinder (22) a main piston (20) of which slides in a front pressure chamber (24) and comprises:

Abstract: A method for manufacturing a brake booster and a device for implementing the a method. The booster comprises an envelope in which there is mounted to slide with sealing a skirt dividing a low-pressure chamber from a variable-pressure chamber, a piston, a three-way valve (19) comprising a plunger distributor (20) formed of a feeler (22) slidably surrounded by a bushing (32) forming part of an emergency brake boosting device. The device also comprises a key for axially indexing the bushing relative to the piston and able to collaborate with a stop means (114) of the bushing for a rate of travel (V) of the distributor above a rate of activation (Vs) allowing the jump to be altered. The bushing (102) according to the invention comprises at least one adjusting means (120) for adjusting the axial position of the stop means relative to the longitudinal ends (101, 103) of the bushing, thus in part determining the activation rate (Vs).

Abstract: This invention mainly relates to a reaction-disk device, to its manufacturing process and to a pneumatic servomotor for an assisted braking, including such reaction device.

Abstract: A pneumatic servomotor for an assisted braking of a motor vehicle having a unidirectional clutch device (56). The clutch device (56) has a coaxial sleeve (58) that slides on a plunger (46), and a substantially ring-shaped key (60) that is arranged with a given clearance around the sleeve (58) and driven by a moving piston (22). When an input force is applied at a determined speed onto a control rod (38) that is integral with the plunger (46), the key (60) rocks and locks a finger (52) that biases the piston (22) with respect to the sleeve (58) in an axial position. The key (60) includes a peg (78) for axial indexing of the locking position of the sleeve (58).

Abstract: The invention relates to a pneumatic servomotor for an assisted braking, comprising a rigid casing (1) in which a moving airtight partition wall (2) defines a front chamber (3) and a rear chamber (4), a pneumatic piston (5) travelling with the moving partition wall (2), a plunger (8), housed within the piston (5) and driven by a control rod (7) and controlling the state of a three-way valve (9), force-transmitting means (10, 13, 17, 18, 31), adapted for receiving and transmitting at least one assistance force (Fa), exerted by a front face (51) of the piston (5) when the valve (9) puts the rear chamber (4) under a second pressure (Pa), the plunger (8) including a front section (81) comprising retaining means (18, 31) intended to tie down the front section (81) of the plunger (8) to the pneumatic piston (5).

Abstract: The invention provides a pneumatic servomotor for an assisted braking of a motor vehicle, of the type comprising a unidirectional clutch device (56), which includes a coaxial sleeve (58), sliding on a plunger (46), and a substantially ring-shaped key (60), arranged with a given clearance around the sleeve (58) and capable of being driven by a moving piston (22), when an input force is applied at a determined speed onto a control rod (38) integral with the plunger (46), so as to rock and lock the sleeve (58) in an axial position, in which it locks a finger (52) biasing the piston (22) independently of the control rod (38), characterised in that the finger (52) is axially integral with the sleeve (58) and in that means are provided for an axial indexing of the locking position of the sleeve (58)

Abstract: A pneumatic servomotor for providing an assisted braking of a motor vehicle. The servomotor includes a plunger arrangement with a unidirectional clutch device (56). The clutch device (56) has a coaxial sleeve (58) that slides on a plunger (46) and a substantially ring-shaped key (60) with a given clearance around the sleeve (58). The key (60) is driven by a moving piston (22) in response to a predetermined rate of speed being applied to a control rod (38) by an input force. The predetermined rate of speed causes the key (60) to rock and lock the sleeve (58) with respect to the piston (22) independently of the control rod (38). The unidirectional clutch device (56) comprises at least one locking transverse face (76) for engagement with the sleeve (58). The face (76) is axially directed rearwards from a front end of the sleeve (58) to form a stop for a peg (78) located on the key (60) that extends radially towards the sleeve (58) for axial indexing an end locking position for the sleeve (58).

Abstract: The invention provides a pneumatic servomotor for an assisted braking of a motor vehicle, of the type comprising a unidirectional clutch device (56), which includes a coaxial sleeve (58), sliding on a plunger (46), and a substantially ring-shaped key (60), arranged with a given clearance around the sleeve (58) and capable of being driven by a moving piston (22) when an input force is applied at a determined speed onto a control rod (38) integral with the plunger (46), so as to rock and lock the sleeve in an axial position, in which it locks the piston (22), independently of the control rod (38), characterised in that the unidirectional clutch device (56) comprises at least one locking transverse face (76) for the sleeve, said face being axially directed rearwards so as to form a stop for a peg (78) provided on the key (60) and extending radially towards the sleeve (58), for an axial indexing of the end locking position of the sleeve (58).

Abstract: The invention relates to a master cylinder with hydraulic reaction, comprising a working chamber (12) in which there slides, under the action of a pushrod (50), a hollow main piston (13) inside which a reaction piston (14), itself moved by a plunger (80), delimits a reaction chamber (15) which communicates with the working chamber (12), a prestressed spring (16) offering resistance to a movement of the reaction piston (14) in the opposite direction (X+X−) from its actuating direction (X−X+). According to the invention, a sliding ring (18) is arranged opposite the plunger (80) so that actuation of the reaction piston (14) by the plunger (80) is also accompanied by compression of the spring (16).