Abstract: The machine includes a rotational mounting bracket, upon which an agricultural disc is supported and held. A hold-down plate that can rotate freely is arranged above the mounting bracket. A linear actuator displaces the hold-down plate vertically in a downwards direction to press the agricultural disc. A laser measurement device is coupled to a linear guide where the hold-down plate forms part of a rotational head-piece fixed to a rod of the linear actuator. A method includes determining a central reference height on a model disc, determining the height of points in the periphery of the disc to be measured, calculating the average of the measured heights and comparing with the central reference height to determine whether the disc is valid or not.

Abstract: A fast-action harrow-disc coupling for fixing a harrow disc (1) to the corresponding hub (2), which is characterized in that it consists of a planet wheel (4) fixed to the corresponding hub (2), the planet wheel (4) being provided on its front face and centrally with a frustoconical projection (5) having a polygonal base, with a section of a threaded shank (6) protruding centrally from the frustoconical projection (5); it being envisaged that the corresponding disc (1) is provided with a central hole (7) for positioning the polygonal base of the frustoconical projection (5), the disc (1) being fixed by means of the thread of a nut (12) onto the section of the shank (6) corresponding to the frustoconical projection (5), with the arrangement, in between, of a plate (9) having a cavity (10) with a central hole (11) for positioning the frustoconical projection (5) and allowing passing out of threaded shank (6), respectively.