The stopper component of a swivel joint, for example, can be formed on the inner circumference of the outer bearing component. The stopper component is engaged in a locking manner corresponding to at least one groove-like recess on the outer circumference of the bearing component, within a specific adjustment position. Relative to this recess, particularly the recess on the outer circumference of the swivel joint bearing component, the stopper component assumes a pre-set position or alignment, especially the terminal position when the cushion is in a horizontal or vertical position.It is also the end position of the rotatable bearing component of the universal joint. The locking part located on the inner circumference of the universal joint bearing component forms, for example, a deformable thickened portion of the material or, for example, a rib.