Abstract: A damping element is provided between bulges of the vertically upwardly extending end sections of the side portions of an upside down U-shaped upper profiled member and the side portions and legs of the upper and lower profiled members. The damping element is made of a deformable semi-flexible material and firmly maintains the upper and lower profiles with respect to one another both in a vertical direction and in a transverse direction.

Abstract: An adjusting mechanism for the back portion of a seat comprises a fixed circular flange attached to an armature of the sitting portion of the seat. The fixed flange has a cup-shaped recess and cutouts spaced at 120.degree. from one another. Each cutout contains a block with an outer toothing. The blocks are resting on block-pushing members each provided with a finger facing the mobile flange. The block-pushing members rest on a cam with three steps. The fingers of the block-pushing members cooperate with a release ring housed inside the mobile flange and having three projections provided for pushing the block-pushing members toward the center of the adjusting mechanism when the cam is pivoted in a direction for moving the back portion of the seat onto the sitting portion.

Abstract: A threaded rod of a variable length has one end connected to a first part of the element to be adjusted. A pivoted detent element cooperates with the threaded rod, with two channels extending diametrically through the pivoted detent element. The first channel has a threaded wall and the second channel has a smooth wall, the second channel forming an angle of preferably about 15.degree. with the first channel. The pivoted detent element is pivotally mounted in a casing and has a protruding tail. A spiral spring is supported between the tail and the casing. The casing further comprises a rear portion connected to a second part of the element to be adjusted.

Abstract: In a hypocycloidal train mechanism, an annular spring is mounted in front of a roller bearing housed between a double satellite and a control cam on a face turned toward a mobile flange. This annular spring has a semicircular cross-section, with one end of the spring being curved and hooked inside a cutout of the control cam, while the other end of the spring is free.