The locking component of the universal joint, such as the one formed on the outer circumference of the bearing component, is shaped to engage and lock with at least one groove-like depression on the outer circumference of the bearing component at a specific adjustment position. Relative to this depression, particularly the one on the outer circumference of the universal joint bearing component, the locking component assumes a pre-set position or alignment, especially the terminal position when the cushion is in a horizontal or vertical position, which also corresponds to the terminal position of the rotating bearing component of the universal joint. The locking component on the inner circumference of the universal joint bearing component is formed as, for example, a deformable thickened portion of the material or a rib.