Abstract: The invention provides a retractile polyarticulated mechanism comprising at least one elementary mechanism (4) formed of two endmost pieces (5, 6) one of which is a reference and, for connecting these endmost pieces (5, 6) together at least three legs (7,8,9) situated in separate planes and formed of two parts (10 and 11, or 12 and 13, or 14 and 15) each associated, on the one hand, with the other part forming the same leg by a spherical connection (16, 17 and 18) and, on the other hand, with an endmost piece (5, 6) different from the one with which this other part is associated by a rotoid connection (either 19 or 20, either 21 or 22, or finally 23 or 24).