| 摘要 |
<p>The jack has a head (1), a base (foot) (2), first (3, 4) and second (5, 6) pairs of link rods which are articulated to the head (1) and to the foot (2) respectively and connected together at (7) and at (8), a clevis piece (9') internal to the quadrilateral and mounted on the connected ends of the link rods (3) and (5) and an operating screw (10) mounted so that it can rotate on the connection (8) between the other two link rods (4, 6) and in a component (11') threaded in a complementary way mounted on the clevis piece. The threaded piece (11') is mounted so it can move on the clevis piece (9') between two predetermined positions separated from one another along the axis of the screw (10), at one of the said predetermined positions which is closest to the adjacent vertex of the quadrilateral defining a predetermined geometry of the jack which is appropriate for it being fitted on a spare wheel. <IMAGE></p> |
