Device for supporting slabs during the phases of punching and in general operations of plastic deformation

A device for supporting a slab (1) during the phases of punching and operations of plastic deformation, said punching and said operations of plastic deformation being carried out by a plurality of tools (5) located above said slab, said slab being movable along two axes, which comprises a plurality of jacks (6), said slab having a lower surface, said slab having two main dimensions, said jacks being placed under said slab (1) in a location corresponding to at least a substantial portion of said surface of the said slab, said jacks being placed at a distance one from the other, said distance being substantially less than the extension of the two main dimensions of said slab, each of said jacks having a stem (7), said stem having in its upper part a mushroom head (8), said head (8) having a top part, a device (9) having load bearing rotating balls being placed on said top part, each of said heads being in contact with said lower surface of said slab, a control system for controlling each of said jacks adapted to lower each of said stems of each of said jacks at a time for an interval of time necessary to avoid interference of said jack with the portions of said slab which have been deformed downwardly, said control systems comprising a reservoir of air (1) and a control valve (11).