| 摘要 |
<p>The invention concerns a spring (4) comprising two branches (41, 42) linked by a bend (40) such that the branches form, at rest, an acute angle, said branches being elastically mobile relative to each other by relative pivoting about the bend until they are urged in contact with each other so as to extend substantially parallel. The invention is characterized in that it comprises means for varying the stiffness of the spring (43, 44) which provide different degrees of stiffness depending on whether the spring is compressed or is slackened, said variation means providing a low degree of stiffness when the branches extend substantially parallel and a higher degree of stiffness when the branches are stressed towards each other from the rest position.</p> |
