| 摘要 |
The present invention relates to jacks for lifting heavy loads with respect to a reference surface 200. The jack 100 according to the invention is essentially characterised by the fact that it includes a base 1 made in two parts 2, 3 which are secured together and each one comprises a bearing face 5, 6 forming between them a dihedron with reentrant angle 4, means 8 for rolling the base over the surface 200, means 11, 17,... for causing the displacement of the rolling means such that they can assume at least two positions located on either side of the plane 19 defined by the bearing face 5 of the part 2, means 20 for applying to the base an elastic force substantially perpendicular to the plane 21 of the bearing face 6, and a single-acting thrust cylinder 29 secured to the second part 3 of the base and capable of deploying itself in a direction 31 perpendicular to the bearing face 6. Application to the lifting of heavy loads such as, for example, aircraft. <IMAGE> |
