This negative-pressure type booster device improves operation feeling for a driver at the time of a sudden braking operation. A valve body is provided with a flange part which extends in the radially outward direction from a front section of the valve body, and a plate is provided with a locking part which comes into contact with the flange part so as to restrict a movement in the axially forward direction relative to the valve body.

This negative-pressure type booster device improves operation feeling for a driver at the time of a sudden braking operation. A valve body is provided with a flange part which extends in the radially outward direction from a front section of the valve body, and a plate is provided with a locking part which comes into contact with the flange part so as to restrict a movement in the axially forward direction relative to the valve body.

A movable diaphragm of a negative pressure type booster device includes an annular rubber diaphragm and an annular metal plate. The diaphragm is airtightly pinched by the housing at an annular outer peripheral bead portion formed at an outer peripheral edge of the diaphragm, and airtightly secured to an outer peripheral portion of a valve body, together with an inner peripheral portion of the plate, at an annular inner peripheral bead portion formed at an inner peripheral edge of the diaphragm. Between the outer peripheral bead portion and the inner peripheral bead portion, there are formed a folded portion having a curved portion toward the front and continuous with the outer peripheral bead portion at an outer peripheral area, and an annular portion continuous with an inner peripheral area of the folded portion and with the inner peripheral bead portion.

A movable diaphragm of a negative pressure type booster device includes an annular rubber diaphragm and an annular metal plate. The diaphragm is airtightly pinched by the housing at an annular outer peripheral bead portion formed at an outer peripheral edge of the diaphragm, and airtightly secured to an outer peripheral portion of a valve body, together with an inner peripheral portion of the plate, at an annular inner peripheral bead portion formed at an inner peripheral edge of the diaphragm. Between the outer peripheral bead portion and the inner peripheral bead portion, there are formed a folded portion having a curved portion toward the front and continuous with the outer peripheral bead portion at an outer peripheral area, and an annular portion continuous with an inner peripheral area of the folded portion and with the inner peripheral bead portion.

A device for varying a pedal resistance of a hydraulic brake system includes at least one electroactive polymer actuator. The device further includes a reaction disc. The reaction disc has at least two polymer actuators. The at least two polymer actuators are independently controllable. Additionally, the at least two polymer actuators are arranged coaxially relative to one another.

A device for varying a pedal resistance of a hydraulic brake system includes at least one electroactive polymer actuator. The device further includes a reaction disc. The reaction disc has at least two polymer actuators. The at least two polymer actuators are independently controllable. Additionally, the at least two polymer actuators are arranged coaxially relative to one another.

A simple, compact, and economical motor/pump unit for supplying vacuum to a pneumatic brake booster of a motor-vehicle brake system, wherein the motor/pump unit is designed as a diaphragm pump having a single elastomeric diaphragm, which is moved by an electrically operated motor unit by an eccentric drive, and has a pump housing and a working-space cover and the diaphragm is clamped between the pump housing and the working-space cover at the radial outer edge of the diaphragm in a sealing manner and the working-space cover is designed as a multi-part working-space cover having an upper cover, a lower cover, and an inlet valve and an outlet valve, which are arranged between the upper cover and the lower cover and control the air circulation through the working space.

A simple, compact, and economical motor/pump unit for supplying vacuum to a pneumatic brake booster of a motor-vehicle brake system, wherein the motor/pump unit is designed as a diaphragm pump having a single elastomeric diaphragm, which is moved by an electrically operated motor unit by an eccentric drive, and has a pump housing and a working-space cover and the diaphragm is clamped between the pump housing and the working-space cover at the radial outer edge of the diaphragm in a sealing manner and the working-space cover is designed as a multi-part working-space cover having an upper cover, a lower cover, and an inlet valve and an outlet valve, which are arranged between the upper cover and the lower cover and control the air circulation through the working space.

A vacuum brake booster for a motor vehicle brake system, comprising a displaceable force input member that is coupled to or can be coupled to a brake pedal, a chamber arrangement arranged in a booster housing having at least one working chamber and at least one vacuum chamber, which are separated from one another via at least one movable wall, a control valve assembly that can be actuated by the force input member, and a force output member for transmitting an operating force to a downstream brake system. The at least one working chamber can be fluidically connected optionally to a negative pressure source or the atmosphere by way of the control valve assembly. The control valve assembly comprises a control valve housing, in which an actuating piston that is coupled with the force input member s displaceably arranged, and a first valve seat, and a second valve seat. Upon an actuation of the force input member, a throttle sleeve can be displaced from the initial position relative to the control valve housing by a predetermined functional path. During the displacement, the throttle sleeve is in abutment with the actuating piston such that a fluidic connection between the at least one working chamber and the ambient atmosphere by way of a throttle window is present. Upon exceeding the functional path, the throttle sleeve lifts off the actuating piston.

A vacuum brake booster for a motor vehicle brake system, comprising a displaceable force input member that is coupled to or can be coupled to a brake pedal, a chamber arrangement arranged in a booster housing having at least one working chamber and at least one vacuum chamber, which are separated from one another via at least one movable wall, a control valve assembly that can be actuated by the force input member, and a force output member for transmitting an operating force to a downstream brake system. The at least one working chamber can be fluidically connected optionally to a negative pressure source or the atmosphere by way of the control valve assembly. The control valve assembly comprises a control valve housing, in which an actuating piston that is coupled with the force input member s displaceably arranged, and a first valve seat, and a second valve seat. Upon an actuation of the force input member, a throttle sleeve can be displaced from the initial position relative to the control valve housing by a predetermined functional path. During the displacement, the throttle sleeve is in abutment with the actuating piston such that a fluidic connection between the at least one working chamber and the ambient atmosphere by way of a throttle window is present. Upon exceeding the functional path, the throttle sleeve lifts off the actuating piston.