Abstract: In a seat having a support frame consisting of a seat portion frame and a backrest portion frame, the backrest portion frame is of a generally L-shaped configuration, with a first limb thereof extending under the seat portion frame. The first limb of the L-shape carries a pivot axis means which is disposed slidably in a pair of rails fixed at the underside of the seat portion frame while the first limb of the L-shaped backrest portion frame is further guided in a second pair of rails at another position spaced from the first pair of rails in such a way that upon forward movement of the seat portion frame the upper end of the backrest portion frame moves in the opposite direction and also moves downwardly, thereby increasing the angle of inclination of the backrest portion, and vice-versa.

Abstract: A seat such as an office chair has at least two gas spring units for performing different functions such as adjusting the angles of inclination of the backrest portion and the seat portion of the chair. The gas spring units are operated by a common operating lever having an operating handle at one end while at its second end it is carried in a vertical slot so as to be pivotable in a horizontal direction about the vertical axis of the slot and slidable lengthwise of the slot. At a location spaced from its second end the lever is mounted in a horizontal slot so as to be pivotable in a vertical direction about the axis of the horizontal slot as well as being slidable lengthwise of the horizontal slot, whereby different spring units can be actuated by different combinations of movements of the lever.

Abstract: In a sprung seat having a scissors-type support assembly with mutually crossing arms for supporting a vertically movable seat portion relative to a base frame, a spring operable to urge the seat portion upwardly thereby to support the weight of the seat occupant acts by way of a slider on a cam lever non-rotatably connected to a support arm. The slider is adjustable in respect of its length for the purposes of height adjustment of the seat portion.

Abstract: A seat such as an office chair comprises a seat carrier assembly carrying an adjustable seat portion and also an adjustable backrest portion. The inclination of the backrest portion can be adjusted by means of a first gas spring unit while inclination of the seat portion is adjusted by means of at least one and preferably two second gas spring units. An actuating lever is operatively connected to the valve actuating members of the respective gas spring units and is pivotable about a pivot point in first and second directions, the second direction being at least substantially perpendicular to the first direction.

Abstract: In a process and apparatus for the production of a cushion element with a cover means enclosing same, at least one cover means is clamped with edge portions thereof between first and second clamping frames in such a way that the cover means defines a space therewithin. The clamping frames with the cover means clamped thereby are then held between first and second mold portions, with the cover means disposed in the mold cavity defined by the co-operation of the clamping frames and the mold portions. The cover means is drawn by suction against the mold cavity surface and a reaction mixture is then introduced into the space defined by the cover means within the mold cavity, through at least one feed opening. After reaction of the mixture the mold portions are separated and the cushion element with cover thereon from the mold.

Abstract: A sliding rail guide arrangement having a locking device for a vehicle seat comprises an outer rail of C-shaped configuration and an inner rail guided displaceably in the outer rail. The locking device comprises a locking lever which is mounted on a mounting member carried on the outside of the outer rail, and the lever carries a locking portion to lock the inner rail with respect to the outer rail. The locking portion, in the locking position, extends through an access aperture in the outer rail and engages into a respective selected locking opening in the inner rail.

Abstract: In a seat having a seat squab portion carried on a support structure, the seat squab portion includes a seat plate which comprises a rearward section fixed to the support structure and a forward section separate from the rearward section. The forward section is adjustable relative to the rearward section by a pivotal movement to vary its angle of inclination and by a sliding movement to vary the depth of the squab portion from front to back. A single control member is provided for both modes of adjustment.

Abstract: A sprung vehicle seat comprises a fluid spring between a base frame and a seat carrier frame displaceable relative to the base frame in respect of height, together with a control means for the fluid spring. The control means includes a switching means and an actuator acting thereon, with movement in respect of height of the seat carrier frame relative to the base frame being converted into a relatively large rotary movement as between the switching means and the actuator means. The structure for converting the heightwise movement into the rotary movement includes a belt winding mechanism wherein extension and retraction of the belt in response to heightwise movement of the seat carrier frame produces the relative rotary movement, or a toothed element meshing with a gear similarly operable to provide the relative rotary movement of substantial magnitude.

Abstract: A springing arrangement comprises a coil spring and a spring-engaging member acting thereon between the two ends of the spring and in a direction which differs from the longitudinal direction of the spring, thereby to provide non-linear dependency of the spring force on the distance covered by the spring-engaging member. The spring-engaging member is made up of two elements on respective sides of the spring, each element bearing against the spring by way of a curved surface and extending over a plurality of turns of the coil spring.

Abstract: An apparatus for producing seat or backrest cushions from plastic foam in which the hardness of the cushion varies in different regions of the cushion. The components for making the different plastic foam mixture are first mixed in a mixing head, and then, depending on the desired hardness of the respective parts of the cushion, the respective mixture is then passed from the mixing head into a mold corresponding to the configuration of the cushion to be produced. The apparatus comprises a mixing head which is stationary in relation to the mold during operation of the process, and communicates with a distributor which opens into the mold and which deflects the respective foam mixture issuing from the mixing head into the designated regions of the mold.