A seat lifter structure which can obtain a rotation of a sector with stable torques is provided. It is equipped with a sector (7) supported to be rotatable by a support member (21), arranged to be facing with a side frame (2) by being pinched and fixed by a pair of expanded portions (6a, 6b) of a tubular shaft member (6) that is supported to be rotatable by the side frame (2), and rotating along the side frame (2) at a time of raising or lowering the side frame (2); a ring shaped spacer (13) having a first ring shaped abutting surface (13da) facing with the sector (7) and having a first outer diameter (13d2), and a second ring shaped abutting surface (13ca) facing with the side frame (2) and having a second outer diameter (13c2) different from the first outer diameter (13d2), which is installed between the sector (7) and the side frame (2) with an axial line (CL6) as a center; and a biasing member (12) that biases and abuts the sector (7) to the first abutting surface (13da) and biases and abuts the side frame (2) to the second abutting surface (13ca) by biasing the sector (7) and the side frame (2) to approach.

A manually operated seat height adjustment actuator mechanism includes a rotatory actuator-driven torque input mechanism defining a first axis and a torque output mechanism defining a second axis offset from the first axis. The rotatory actuator-driven torque input mechanism is provided by a planetary gear assembly. The torque output mechanism comprises a cycloidal drive assembly including eccentrically driven gears. Linking gearing operatively links the torque input mechanism and the torque output mechanism. The eccentrically driven gears engage an output pinion configured to engage a gear segment of a seat height adjustment mechanism for raising and lowering a seat.

Suspension device for a vehicle seat, comprising an upper suspension portion and a lower suspension portion, which are interconnected by a first swivel connector and a second swivel connector, wherein the suspension device comprises a first adjustable toothed wheel element arranged on the upper suspension portion, a second toothed wheel element connected to the first swivel connector for adjusting a position of a first spring unit, by means of which a spring force and a spring rate of the suspension device can be changed, and a third toothed wheel element which is at least operatively connected to the first and the second toothed wheel element and is connected to the first swivel connector.

An arrangement for manipulating the flow of a fluid into a fluid actuator, preferably of a seat, has a base body having an opening designed to introduce the fluid into the base body, and at least one further opening provided for forwarding or discharging the fluid introduced into the base body. Means for producing and/or interrupting a fluid-conducting connection between the openings are provided. The means comprise such additional means that can be charged with a pressure of the fluid to be conducted and are designed such that, in a first pressure range of the fluid, the fluid entering the base body from the fluid actuator is discharged via one of the openings from the base body to the surroundings and, in a second pressure range of the fluid that is higher than the first pressure range, the fluid introduced into the base body is introduced into the fluid actuator.