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.

Abstract: The invention relates to a waste grinder such as a vehicle tyre bi-rotor grinder, some of its component parts (rotor, shearing wheel) as well as to a method for maintenance of the said grinder. The grinder comprises at least one rotor which has at least one shearing wheel comprising: a ring-support (6), which is designed to be rotated by a shaft (3) and defines a plurality of peripheral sections, a plurality of shearing blades (8,9) which are disposed corresponding to the sections such as to project radially relative to the peripheral surface of the ring-support (6), the said wheel being characterised in that it comprises a plurality of blade-holder parts (7), onto which the blades (8,9) are secured by detachable means for securing (11,13) which are accessible from the outer lateral shearing surfaces of the blades, the blade-holder parts (7) being designed to be applied and to be secured by detachable means for securing (17) onto the sections of the peripheral surface of the ring-support (6).

Abstract: A loss-proof fastener of the type comprising a fastener member including a shank portion having an annular groove (2) and a ring (3) in the groove and transversely split (7) so as to provide an elastic deformation in the direction of the circumference, whereby in a rest condition the ring projects beyond the shank portion surface and in a compressed condition is retracted within the groove, the ring having a cross-section such that the ring is elastically deformable so as to be capable of transverse elongation and radial contraction when the ring is compressed, and the ring when positioned in the groove having a lateral play to permit the cross-section thereof to freely deform when compressed between the rest and the compressed conditions.