摘要 |
Hinge structures are disclosed which are useful in seats with adjustable backrests, the structures including a gear unit (6, 8) in which indented and protruding tooth systems (6a, 8a) are punched into the hinge pieces using the precision blanking process, the diameter as well as the tooth contour of the protruding tooth system (8a) being at least partially smaller than the diameter and the tooth contour of the associated indented tooth system (6a) so that material can then flow from the unused tooth system produced during precision blanking and into the effective tooth system, thus enlarging the tooth width (b) of the effective tooth system to be greater than the thickness (d) of the initial material. See FIGS. 4a and 5a. |