Patent ID: 8899345

Claim:
A fast-action harrow-disc coupling, for fixing a harrow-disc ( 1 ) to a hub ( 2 ) provided in a main frame of a harrow, comprising a planet wheel ( 4 ) solidly connected to the hub ( 2 ), said planet wheel ( 4 ) having a front face, which, at a center thereof includes a frustoconical projection ( 5 ) having a polygonal base, with a section of an outwardly threaded shank ( 6 ) centrally protruding from said frustoconical projection ( 5 ); a harrow-disc ( 1 ) having a central hole ( 7 ) through which the frustoconical projection ( 5 ) projects, the central hole ( 7 ) having a shape that provides for positional adjustment of the harrow-disc ( 1 ) relative to the polygonal base of the frustoconical projection ( 5 ), said harrow-disc ( 1 ) being fixed by threading a nut ( 12 ) on the section of the outwardly threaded shank ( 6 ) of the frustoconical projection ( 5 ), with an interposition of a plate ( 9 ) provided with a cavity ( 10 ) with a central hole ( 11 ), the cavity having a shape that fits to the shape of the frustoconical projection ( 5 ) and the threaded shank ( 6 ) protruding from the central hole; wherein said harrow-disc ( 1 ) has a concentric housing ( 8 ), at a bottom of which the central hole ( 7 ) is formed, the plate ( 9 ) being positioned in the housing ( 8 ).