Patent ID: 6986425

Claim:
An apparatus for separating a loose mass formed by elements or materials of different sizes, comprising: a separation chamber into which said mass is able to be inserted, a plurality of riddling rolls, mounted inside said chamber, rotating on axes of rotation parallel to each other and lying substantially on a same plane, wherein each of said riddling rolls comprises a central shaft and a plurality of riddling elements mounted on said central shaft, wherein each of said riddling elements is substantially square in shape, to form four cusps disposed at 90° with respect to each other, wherein said riddling elements are adjacent to each other so that said cusps form a plurality of grooves, wherein said riddling rolls are axially staggered therebetween so that the cusps of the riddling elements of each roll are able to be constantly inserted, during rotation of the riddling rolls, more or less deeply, into the corresponding grooves of the adjacent riddling roll, to define discharge apertures with an alternated profile, wherein said cusps are pointed with a substantially sharp, joined or rounded edge, and wherein the lateral surfaces of each of said riddling elements converge from said central shaft towards the periphery of said edge, wherein said grooves are substantially V-shaped and said alternated profile has a zig-zag shape.