Abstract: A seat suspension device for an automotive seat, in which an upper frame is movably connected with a lower frame via an X-shaped link in a vertically movable manner, with the arrangement that an upwardly curved section is formed at the frontal part of the upper frame whereas a downwardly curved section is formed at the frontal part of the lower frame, and that a damper is interposed vertically between those upwardly and downwardly curved sections.

Abstract: A suspension device for automotive seat which is provided with a hydraulic damper and a compression coil spring wound therearound, such that the coil spring is adjusted in elastic repercussion force by way of worm gear and worm wheel so as to permit a fine adjustment of the repercussion force of the coil spring. A casing may be provided for housing the worm gear and worm wheel, and an indicator is formed on the casing. Below the casing, a scale plate having a desired plural graduation lines or marks is provided, to thereby precisely set a desired reprecussion force of the spring.

Abstract: A suspension device for seat which includes a torsion bar interposed between an upper movable frame and a lower base frame, the torsion bar being adapted to bias the upper movable frame upwardly, and a spring provided on a shock absorber which is extended between the upper movable and lower base frames. The repercussive force of the suspension device is increased by the torsion bar and spring, against a downward load applied on the seat.

Abstract: An automotive seat with a suspension device has an X-shaped link mounted between an upper seat frame and lower floor frame. The X-shaped link is equipped with a seat belt anchor and a sublink link slideably connected between one of the link members of the X-shaped links and the lower floor frame. The sublink has an elongated hole at one of its ends which is slideably engaged to a pin on one of the link members of the X-shaped links. The other end of the sublink is pivotally connected to the lower floor frame. When a force is exerted on the seat belt anchor, it is transmitted through the sublink directly to the floor, thereby preventing damage or deformation of the suspension device. Further, when the suspension is contracted, the X-shaped link and the sublink are hidden behind the upper and the lower frames thereby creating a suspension device with a very low profile.