Bidirectional pressure supply system in a motor vehicle

Bidirectional pressure supply system for consumers in a motor vehicle which are to be operated with fluid, comprising a pneumatic pressure generator simultaneously admitting negative pressure to a negative pressure line system and positive pressure to a positive pressure line system;

• directional control valve for the alternate connection of consumers to one of the completely separate line systems via consumer individual lines;
• at least one pressure-dependently responding limit stop switch for the pressure generator;
• directional control valves arranged parallel to each other and adapted to be electromagnetically switched independently of each other for selectively switching the respective consumer individual lines individually and in groups between positions connected to the respective negative and positive pressure line systems and position separated from both, and
• electrical triggering means for initiating operation of the pressure generator and admitting the respective supply of negative and positive pressure to the respective negative and positive pressure line systems;
• and
• wherein each of the negative and positive pressure line systems contain a pressure-dependently responding limit stop switch for the pressure generator and a safety valve in the form of a blow-off valve in the positive pressure line system and an intake valve in the negative pressure line system, which safety valves only open after response of the associated limit stop switch in the same line system to protect the pressure generator against overloading when not consuming the respective pressure type (p.sub.u or p.sub.uml) if the pressure generator is in operation via the limit stop switch assigned to the other line system.