Abstract: A device for slidingly displacing or shifting a heavy load along a sliding comprises a platform provided with double-acting hydraulic jacks and resting on a guide rail. The platform is provided with hooks movable in a vertical direction and adapted to penetrate, when in their lowered position, apertures provided in the rail. Each hook has an oblique surface at the front end of the hook, which surface forms a sliding ramp adapted to slide on the front edge of an aperture wherein the hook is engaged. Each hook further has a locking surface at its rear end, which is adapted to cooperate with the rear edge of said aperture. The distance between any two adjacent ones of the apertures provided in the rail is at least substantially equal to the stroke length of the jacks, whereby the actuation of the jacks allows the load to be displaced by incremental movements.

Abstract: A method of fluidifying powderous substances which are in contact with a wall, wherein the surface of the wall in contact with said substances is provided with at least one substantially semi-lenticular chamber delimited by said surface and by a flattened dome made of a resiliently flexible material. The invention also relates to an apparatus for carrying out this method.