Solenoid valve

1. Solenoid valve comprising:

an input port including an input sealing tip which is spring biased for closing it, a first output port, a second output port to the environment including an output sealing tip which is spring biased for closing it, and a solenoid coil arrangement for selectively generating magnetic fields which result in a force either on the input sealing tip to pull it away from the input port for opening it or a force on the output sealing tip to pull it away from the second output port for opening it, characterized in that the solenoid valve arrangement consists of a single solenoid coil, a permanent magnet is disposed moveably in axial direction of the solenoid coil to be driven by a magnetic field of the solenoid coil of a first polarity to move in a first axial direction of the solenoid coil and by a magnetic field of opposite polarity to move in a second direction opposite to the first direction, said permanent magnet being connected to the input sealing tip and to the output sealing tip such that movement of the permanent magnet in the first direction pulls the input sealing tip away from the input port to open it while the second output port remains closed, and movement of the permanent magnet in the opposite direction pulls the output sealing tip away from the second output port to open it while the input port remains closed;

a first transverse lever that extends transversely to the axial direction of the solenoid coil at one end thereof and is connected with its end remote from the solenoid coil to a first actuation shaft rotatably mounted in the housing of the valve; and

a second transverse lever extends transversely to the axial direction of the solenoid coil at the other end thereof and is connected with its end remote from the solenoid coil to a second actuation shaft rotatably mounted in the housing of the valve.

2. A solenoid valve comprising:

an input port including an input sealing tip which is spring biased for closing it,

a first output port,

a second output port to the environment including an output sealing tip which is spring biased for closing it, and

a solenoid coil arrangement for selectively generating magnetic fields which result in a force either on the input sealing tip to pull it away from the input port for opening it or a force on the output sealing tip to pull it away from the second output port for opening it, characterized in that the solenoid valve arrangement consists of a single solenoid coil,

a first permanent magnet disposed within a first half of the solenoid coil with its north pole pointing in an axial direction of the solenoid coil, and a second permanent magnet is disposed in the opposite half of the solenoid coil with its north pole pointing in the opposite axial direction of the solenoid coil, and

wherein the first permanent magnet and the second permanent magnet are connected to the input sealing tip and to the out-put sealing tip such that movement of the first permanent magnet and the second permanent magnet in the first direction pulls the input sealing tip away from the input port to open it while the second output port remains closed, and movement of the first permanent magnet and the second permanent magnet in the opposite direction pulls the output sealing tip away from the second output port to open it while the input port remains closed.

3. Solenoid valve according to claim 2 , wherein the first permanent magnet is provided with an output plunger rod projecting out of the solenoid coil and extending in the direction towards the second output port and carrying the output sealing tip, and that the second permanent magnet is connected to an input plunger rod projecting out of the solenoid coil and extending towards the input port and carrying the input sealing tip at its outer end, and that a spring arrangement is provided which results in a spring bias force urging the output plunger rod with the output sealing tip to the second output port and urging the input plunger rod with the input sealing tip to the input port.

4. Solenoid valve according to claim 3 , wherein the spring arrangement comprises a spring acting between the first and second permanent magnets urging them away from each other.

5. Solenoid valve according to claim 3 , wherein the first and second permanent magnets are connected to each other, and springs are acting on the input sealing tip and on the output sealing tip to urge them towards the input port and towards the second output port, respectively.

6. A solenoid valve comprising:

an input port including an input sealing tip which is spring biased for closing it, a first output port, a second output port to the environment including an output sealing tip which is spring biased for closing it, and a solenoid coil arrangement for selectively generating magnetic fields which result in a force either on the input sealing tip to pull it away from the input port for opening it or a force on the output sealing tip to pull it away from the second output port for opening it, characterized in that the solenoid valve arrangement consists of a single solenoid coil, that a permanent magnet is disposed moveably in axial direction of the solenoid coil to be driven by a magnetic field of the solenoid coil of a first polarity to move in a first axial direction of the solenoid coil and by a magnetic field of opposite polarity to move in a second direction opposite to the first direction, said permanent magnet being connected to the input sealing tip and to the output sealing tip such that movement of the permanent magnet in the first direction pulls the input sealing tip away from the input port to open it while the second output port remains closed, and movement of the permanent magnet in the opposite direction pulls the output sealing tip away from the second output port to open it while the input port remains closed;

wherein the permanent magnet is connected to the input sealing tip by a first flexible cord and is connected to the output sealing tip by a second flexible cord extending in the opposite direction to the first cord, and wherein springs are arranged to exert bias force on the input sealing tip towards the input port and the output sealing tip towards the second output port, wherein the lengths of the first and second cords are dimensioned such that the first and second cords are under no tension when the solenoid coil is inactivated and that a respective one of the sealing tips is lifted off its port by a pulling force exerted through the respective cord when the solenoid coil is activated by a voltage of a respective polarity.

7. Solenoid valve according to claim 1 , wherein the permanent magnet is provided with an input plunger rod extending therefrom towards the input sealing tip and an output plunger rod extending therefrom in the opposite direction towards the output sealing tip, wherein the input sealing tip is spring-biased to be pressed onto the input port opening from the outside, and the output sealing tip is spring-biased to be pressed on the second output port opening from the outside, and wherein the plunger rods each have a sufficient length such that the input plunger rod reaches the input sealing tip when the permanent magnet is moved in a first direction upon generation of a magnetic field of a first polarity and lifts the input sealing tip off the input port opening, and that the output plunger rod reaches the output sealing tip upon generation of a magnetic field of opposite polarity to lift it off the second output port opening.

8. Solenoid valve according to claim 6 , wherein the permanent magnet is formed by a first permanent magnet disposed within a first half of the solenoid coil with its north pole pointing in an axial direction of the solenoid coil, and a second permanent magnet disposed in the opposite half of the solenoid coil with its north pole pointing in the opposite axial direction of the solenoid coil, wherein the first and second permanent magnet are connected to each other.

9. Solenoid valve according to claim 1 , wherein:

the first actuation shaft is connected to a first actuation lever connected to the input sealing tip such that by moving the permanent magnet in direction towards the first transverse lever it is pivoted and turns the first actuation shaft which turns the first actuation lever and thereby lifts off the input sealing tip from the input port to open it, and

the second actuation shaft is connected to a second actuation lever connected to the output sealing tip such that by moving the permanent magnet in direction towards the second transverse lever it is pivoted and turns the second actuation shaft which turns the second actuation lever and thereby lifts off the output sealing tip from the second output port to open it.

10. Solenoid valve according to claim 9 , wherein the length of the first transverse lever is larger than the length of the first actuation lever and that the length of the second transverse lever is larger than the length of the second actuation lever.

11. Solenoid valve according to claim 10 , wherein the solenoid coil is sur-rounded by ferromagnetic material in order to reduce the reluctance in the magnetic circle of the coil.

12. A vehicle seat adjustment system comprising, a solenoid valve according to claim 1 for connection with its input port to a pressurized air source and connected with its first output port to an air cell in a vehicle seat, a control unit which is arranged to receive voltage from a voltage supply and to selectively supply voltage of a first polarity to the solenoid coil or voltage of a second polarity opposite to the first polarity.