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US 5,293,808 AGranted
Vacuum brake power booster
AssigneeAlfred Teves GmbH
InventorsManfred Rueffer, Ralf Jakobi, Jurgen Bauer, Peter Kraft
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AssigneeAlfred Teves GmbH
InventorsManfred Rueffer, Ralf Jakobi, Jurgen Bauer, Peter Kraft
Estimating the term…
A vacuum brake power booster and a process is disclosed in which a precise adjustment of the power boost startup characteristic is achieved. The adjustment is carried out as a final step in the manufacture of the booster adjusting the distance between the valve piston and an elastic reaction distance. During adjustment, the vacuum brake power booster has a vacuum applied. A pre-established input force is exerted on the piston rod while simultaneously measuring the output force exerted by the push rod, and the axial length of the valve piston is modified until the measured output force is within a pre-established range. The adjustment is carried out by modifying the length of a two piece valve piston or by temporarily extending a rod within the valve piston until a correct output force is reached and thereafter removing the rod and inserting a transmission pin of a length determined by the extent of travel of the rod at the point at which the desired output force was attained.
A vacuum brake power booster for increasing the force between an input piston rod and a power output push rod, said power booster including a booster housing which is sealingly divided into a vacuum chamber and a power chamber by an axially movable wall being adapted to be subjected to a pneumatic pressure differential, a control housing, a control valve including means which controls the pressure differential positioned within said control housing, said control valve actuatable by a valve piston, said valve piston slidable by means of engagement with said piston rod, transmission means causing said valve piston to have a force-transmitting connection with said push rod, said transmission means including a transmission ratio disc and an elastic reaction element, and wherein said valve piston includes means which in the assembled condition of the brake power booster enable a modification of the effective axial length thereof from said point of engagement with said piston rod to the point of engagement with said reaction disc;
A vacuum brake power booster for increasing the force between an input piston rod and an output push rod, said power booster including a booster housing which is sealingly divided into a vacuum chamber and a power chamber by an axially movable wall being adapted to be subjected to a pneumatic pressure differential, a control housing, a control valve including means which controls the pressure differential positioned within said control housing, said control valve actuable by a valve piston, said valve piston slidable by means of engagement with said piston rod, transmission means causing said valve piston to have a force-transmitting connection with said push rod, said transmission means including a transmission ratio disc and an elastic reaction element, wherein said valve piston includes a front part axially guided within the said control housing and a power transmission pin slidably guided within a bore in said front part and which transmission pin has a radial step in abutment against said front part in an axial direction, said transmission pin drivingly engaged with said reaction element on one end, and with said piston rod and the other end.
A process for assembling a vacuum brake power booster having an elastic reaction disc interposed between a booster power controlling valve piston and an output push rod, said valve piston advanced by an input piston rod to control the power boost, and a transmission disc interposed between the relative valve piston and the reaction disc, a process a vacuum chamber adapted to be subjected to vacuum and a power chamber vented by an input force acting on said valve piston to generate an output force on said push rod, said process comprising the steps of applying a predetermined input force on said valve piston while simultaneously measuring the output forces, and adjusting the effective axial length of said valve piston from said push rod to said reaction disc to cause said output force to fall into predetermined output force range.
A process for adjusting a characteristic of a brake power booster of the type including an input piston rod, an output push rod, a housing having a vacuum chamber and a power chamber formed by an axially movable wall subjected to a pressure differential acting thereacross to generate a boosting force acting on said output push rod, a control valve controlling the magnitude of said pressure differential including a valve piston movable by engagement of one end thereof with said input piston rod, an elastic reaction element interposed between said valve piston and said output push rod and a transmission element positioned at the other end of said valve piston and having a surface engaging said elastic reaction element, the process comprising the steps of
Dependencies are inferred from the claim text.