Abstract: A waste comminuting device includes a comminuting housing (1), a rotor (2) provided with a plurality of protruding peripheral knives, stationary counterblades supported by the comminuting housing, the minimal distance separating each knife from each associated counterblade, during the passage of the knife opposite the counterblade, being equal to an operating clearance, called the cutting size. For each knife (3, 4, 5, 6) and for at least one direction of rotation of the rotor, at least two non-aligned counterblades (7 and 11, 8 and 12, 9 and 13, 10 and 14) associated with the knife are adapted so that the distance separating the leading edge (45) of the knife and the leading edge (48, 56) of a counterblade at the moment when the leading edge of the knife opposes the leading edge of the counterblade, is different from one counterblade (7-10) to another (11-14).

Abstract: A waste grinder and a method for maintenance of the grinder. The grinder comprises at least one rotor which has at least one shearing wheel comprising: a ring-support, which is designed to be rotated by a shaft and defines a plurality of peripheral sections, a plurality of shearing blades which are disposed corresponding to the sections such as to project radially relative to the peripheral surface of the ring-support, the wheel comprises a plurality of blade-holder parts, onto which the blades are secured by detachable securing elements which are accessible from the outer lateral shearing surfaces of the blades, the blade-holder parts being designed to be applied and secured by detachable elements for securing onto the sections of the peripheral surface of the ring-support.