Lucas Industries Limited

Lucas Automotive Gmbh

Lucas Varity Gmbh

Peter Schl&uuml;ter

Heinrich Plewnia

Ludwig Friedsam

Gerd Puscher

Michael Possmann

A vacuum brake booster comprises a vacuum chamber and a working chamber which is separated in a pressure-tight manner from the latter by a mobile wall. In order to obtain a pressure difference at the mobile wall, a control valve is provided which comprises a housing coupled in a force-transmitting manner to the mobile wall and a first valve seat, which is disposed in the housing and which, in co-operation with a first valve sealing member, controls the supply of atmospheric pressure or overpressure to the working chamber in response to the displacement of an input member, which is coupled to the first valve seat, of the brake booster in order to obtain a pressure difference at the mobile wall. The first valve seat is formed at a displaceable valve member which is coupled to the input member in the actuating direction of the brake booster. The control valve comprises a second valve seat which, in co-operation with the first valve sealing member, controls a connection between the vacuum chamber and the working chamber. In order to achieve emergency brake assistance (brake assistant function), the valve member is constantly subjected to the pressure prevailing in the working chamber at its rear side, which is turned towards the input member. After the displaceable valve member has exceeded a prefixed displacement in the actuating direction relative to the control valve housing, the valve member is subjected over at least a part of its front side, which lies opposite the rear side, to the pressure prevailing in the vacuum chamber. The pressure difference then acting on the displaceable valve member holds it in the position reached until pressure equalisation between the front side and the rear side of the displaceable valve member takes place. In order to disconnect the brake assistant function, a component which is coupled to the input member in the direction opposite to the actuating direction of the brake booster acts on the first valve sealing member and lifts it off the second valve seat after a prefixed displacement of the input member.

Vacuum brake booster with improved magnet-free emergency brake assistance system

A vacuum brake booster ( ) has a vacuum chamber ( ) and a working chamber ( ), which are separated from one another in a pressure-proof manner by a movable wall ( ). A control valve ( ), which has a housing ( ) workingly coupled to the movable wall ( ), has a valve seat ( ), which is disposed in the housing ( ) and which in dependence upon the displacement of an input element ( ) may control the supply of at least atmospheric pressure to the working chamber ( ) in order to achieve a pressure difference at the movable wall ( ). For improved braking force assistance during emergency braking operations, an armature ( ) cooperating with a permanent magnet ( ) is provided in the control valve housing ( ) and coupled in actuating direction to the actuating element ( ). The armature ( ) is spring-biased counter to actuating direction and, in the normal position of the control valve ( ), is held at a first distance from the permanent magnet ( ). In the course of an approach towards the permanent magnet ( ) the armature ( ), when it is less than a previously defined second distance away, which is smaller than the first distance, is pulled by the permanent magnet ( ) counter to the spring bias acting upon the armature ( ) and with simultaneous cancellation of its, in actuating direction, rigid coupling to the actuating element ( ) into abutment with the permanent magnet ( ). For adjusting the distance between the armature ( ) and the permanent magnet ( ) in the non-actuated state of the vacuum brake booster ( ), the axial position of the permanent magnet ( ) relative to the control valve housing ( ) and/or the distance between the armature ( ) and the valve seat ( ) is adjustable.

Vacuum brake booster with mechanical emergency braking assistance

A vacuum brake booster ( ) is described, comprising a vacuum chamber ( ) and a working chamber ( ) separated from each other by a movable wall ( ). The vacuum brake booster ( ) includes an emergency braking aid comprising a permanent magnet ( ), which is disposed in the control valve housing ( ), and an armature ( A) which cooperates with the permanent magnet ( ) and in the event of emergency braking is drawn into abutment with the permanent magnet ( ), with the result that a control valve ( ) is held open for the supply of atmospheric pressure or above-atmospheric pressure to the working chamber ( ). The permanent magnet ( ) and the armature ( A) form a two-component magnetic module ( A, ), of which a first component is rigidly coupled to an actuating piston ( ) of the brake booster ( ). A coupling device ( ) is provided which is adapted to couple the second component of the magnetic module ( A, ), at least in actuating direction, to the actuating piston ( ) in response to high reaction forces.

Vacuum brake booster with mechanical emergency braking aid

A vacuum brake booster ( ) is described, having a vacuum chamber ( ) and a working chamber ( ) separated from one another by a movable wall ( ), and a control valve ( ), which comprises a housing ( ) coupled workingly to the movable wall ( ) and which to achieve a pressure difference at the movable wall ( ) is capable of controlling the supply of atmospheric pressure or above-atmospheric pressure to the working chamber ( ) in dependence upon the displacement of an actuating piston ( ). The vacuum brake booster ( ) has an emergency braking aid comprising a permanent magnet ( ) and an armature ( ), which cooperates with the permanent magnet ( ) and is resiliently biased counter to actuating direction and during an emergency braking operation is drawn into abutment with the permanent magnet ( ), with the result that the control valve ( ) is held open for the supply of atmospheric pressure to the working chamber ( ). The vacuum brake booster ( ) comprises a coupling device ( ) for detachably coupling the armature ( ) to the actuating piston ( ).

A pneumatic brake booster ( ) has a booster housing ( ), the interior of which is subdivided by at least one movable wall ( ) into a vacuum chamber ( ) and a working chamber ( ). Along an axis (A) a control valve ( ) for controlling a pneumatic pressure difference acting upon the movable wall ( ) projects into the booster housing ( ). The movable wall ( ) is workingly connected to the outside of a substantially cylindrical control valve housing ( ), in that a collar ( ) of a plate ( ) associated with the movable wall ( ) is deformed along its periphery at least in sections radially into the control valve housing ( ). In order to simplify manufacture of the brake booster ( ), in the portion ( ) of the control valve housing ( ) overlapped by the collar ( ) of the plate ( ) a plurality of recesses ( ) are provided, which are spaced apart from one another in peripheral direction and into which the collar ( ) of the plate ( ) is radially deformed. The recesses ( ) are accessible from the end of the control valve housing ( ) disposed in the booster housing ( ).

Pneumatic brake booster and method of manufacturing it

A vacuum brake booster comprising a vacuum chamber ( ) and a working chamber ( ), separated by a movable wall ( ) coupled to a housing ( ). A control valve ( ) includes a first valve seat ( ) formed on a displacement valve member ( ) and cooperating with a first valve seat member ( ), to control a supply of atmospheric pressure to the working chamber. A rear side of the valve member is constantly subjected to pressure in the working chamber. When the valve member is displaced more than a predetermined distance in the actuating direction relative to the housing, a front side of the valve member is subjected to pressure in the vacuum chamber, such that a differential pressure acts on the valve member, to hold the valve member in a displaced position until pressure equalization between the first and rear sides of the valve member is effected.

Vacuum brake booster with magnet-free emergency breaking assistance system

A vacuum brake booster ( ) has a vacuum chamber ( ) and a working chamber ( ), which are separated in a pressure-proof manner from one another by a movable wall ( ). A control valve ( ) having a housing ( ), which is workingly coupled to the movable wall ( ) and in which a first valve seat ( ) is disposed, in order to achieve a pressure difference at the movable wall ( ) controls the supply of at least atmospheric pressure to the working chamber ( ) in dependence upon the displacement of an input element ( ), which is coupled to the first valve seat ( ), of the brake booster ( ). Disposed in the control valve housing ( ) is an armature ( ), which cooperates with a permanent magnet ( ) and which is coupled on the one hand to the input element ( ) in actuating direction and on the other hand to the first valve seat ( ). A spring ( ) biases the armature ( ) counter to actuating direction and in the starting position of the control valve ( ) holds the armature ( ) at a first distance from the permanent magnet ( ). The armature ( ) in the course of a movement towards the permanent magnet ( ), when it is less than a previously fixed second distance, which is less than the first distance, away from the permanent magnet ( ), is pulled counter to the force exerted by the spring ( ) upon the armature ( ) and with simultaneous cancellation of its, in actuating direction, rigid coupling to the input element ( ) into abutment with the permanent magnet ( ). To dampen undesirable impact noises, the spring ( ), which biases the armature ( ) counter to actuating direction, is mechanically coupled to the input element in such a way as to cushion the return stroke motion of the input element ( ), which follows a detaching of the armature ( ) from the permanent magnet ( ), before the input element ( ) has completed its maximum possible return stroke relative to the control valve housing ( ).

Vacuum brake booster with mechanical emergency braking assistance and improved noise damping

A vacuum brake booster ( ) has a vacuum chamber ( ) and a working chamber ( ) separated from one another in a pressure-proof manner by a movable wall ( ). A control valve ( ), which comprises a housing ( ) workingly coupled to the movable wall ( ), has a first valve seat ( ), which is disposed in the housing ( ) and to achieve a pressure difference at the movable wall ( ) is capable of controlling the supply of at least atmospheric pressure to the working chamber ( ) in dependence upon the displacement of an input element ( ) coupled to the first valve seat ( ). For improved boosting of the brake force during emergency braking operations, an armature ( ), which cooperates with a permanent magnet ( ), is provided in the control valve housing ( ) and is rigidly coupled on the one hand to the actuating element ( ) in actuating direction and on the other hand to the first valve seat ( ). The armature ( ) is resiliently preloaded counter to actuating direction and in the starting position of the control valve ( ) is held at a first distance from the permanent magnet ( ). The armature ( ), as it approaches the permanent magnet ( ) and is less than a previously defined second distance away, which is smaller than the first distance, is pulled by the permanent magnet ( ) counter to the resilient preloading force acting upon the armature ( ) and with simultaneous cancellation of its, in actuating direction, rigid coupling to the actuating element ( ) into contact with the permanent magnet ( ).

Growing community of inventors

Kammerforst, Germany

Peter Schlüter

Growing community of inventors

Kammerforst, Germany

Peter Schl&uuml;ter

Peter Schlüter