Rotational damper and seating arrangement

1. A rotational damper, comprising:

a fluid-filled damper housing and

a piston rotatably accommodated in the damper housing by a rotation axis of the rotational damper in a first direction and an opposite second direction with a piston rod extending in the direction of the rotation axis;

whereby the piston has at least one opening with a flow cross-section, which allows for the flow of fluid through the piston,

whereby a total flow cross-section is calculated from the flow cross-section of the at least one opening,

wherein a blocking device is assigned to the piston, which is capable of reducing the flow cross-section of the at least one opening during a rotation of the piston in a first direction relative to a rotation of the piston in the second direction, and

wherein at least one bypass channel is provided atformed on the inside of a bottom floor of the damper housing across at least one rotation angle section which facilitates the flow of fluid around the piston in the direction against the rotation of the piston.

2. A seating arrangement with a fixed seat and a tiltable backrest for a vehicle, wherein the damper of claim 1 is provided between the fixed seat and the tiltable backrest which, when the backrest is tilted from the substantially vertical position to the substantially horizontal position, has a greater damping force than during an opposite movement of the backrest, in particular a rotational damper.

3. A seating arrangement according to claim 2 , wherein the damper has an increasing damping force when the backrest is tilted from the substantially vertical position in the substantially horizontal position.

4. A seating arrangement according to claim 3 , wherein the backrest and the damper are adapted to each other in such a way that a substantially constant force must be applied when the backrest is tilted from the substantially vertical position to the substantially horizontal position.

5. A rotational damper according to claim 1 , wherein the blocking device through which at least one elastic plate is formed is assigned to the piston in such a way that it at least partially covers the at least one opening during a rotation of the piston in the first direction and substantially exposes the at least one opening during a rotation in the second direction.

6. A rotational damper according to claim 5 , wherein the elastic plate comprises at least one opening which overlaps at least partially with the at least one opening of the piston during the rotation of the piston in the first direction.

7. A rotational damper according to claim 1 , wherein the total flow cross-section is greater than zero at a rotation of the piston in the first direction.

8. A rotational damper according to claim 1 , wherein the piston is formed point symmetrically or rotation symmetrically relative to the rotation axis.

9. A rotational damper according to claim 1 , wherein at least one stop is provided at the inner wall of the damper housing which limits a rotation of the piston at a predetermined angle position.

10. A rotational damper according to claim 1 , whereby at least one sealing member is provided between the piston and the inner wall of the damper housing.

11. A rotational damper according to claim 1 , wherein the piston comprises a substantially circular hub area in the area of the rotation axis from which at least one wing area extends in the direction of the inner wall of the damper housing, whereby furthermore at least one protrusion extends in the direction of the hub area from the inner wall of the damper housing.

12. A rotational damper according to claim 1 wherein the rotational damper is provided between a seat of a vehicle and the vehicle and/or between the seat and a tiltable backrest of the vehicle, whereby the seat is rotatable from its horizontal position relative to the vehicle and/or the backrest, tiltable from a substantially horizontal position to a substantially vertical position, and whereby one of the damper housings and the piston rod are assigned to the seat and the other of the two to the backrest and/or the vehicle.

13. A rotational damper, comprising:

a fluid-filled damper housing; and

a piston rotatably accommodated in the damper housing by a rotation axis of the rotational damper in a first direction and an opposite second direction with a piston rod extending in the direction of the rotation axis,

wherein at least one bypass channel is provided at the inside of a bottom floor of the damper housing across at least one rotation angle section which facilitates the flow of fluid around the piston in the direction against the rotation of the piston, and

wherein a separate floor is provided within the damper housing that is movable along the rotation axis by displacement of the fluid within the damper housing, the floor being preloaded in an axial direction toward the piston by an elastic member.

14. A rotational damper according to claim 13 , wherein the least one bypass channel comprises a variable cross-section in a circumference direction.

15. A rotational damper according to claim 13 , wherein an axial sealing member is assigned to the piston, whereby the floor abuts against the axial sealing member due to the effect of the elastic member.

16. A rotational damper according to claim 13 , further including a thermal expansion member which is configured and arranged in such a way that it moves the floor further in the direction of the piston as the temperature increases.