| abstract |
A forage harvester (10) has a control for automatically controlling the movement of a sharpening stone (20) to sharpen the knives of a rotating cutterhead (12). The stone (20) is moved toward and away from the cutterhead (12), and also across it for the sharpening. n The control unit involving a programmed microprocessor (U4) responds, for example, to knock sensors (34, 36) signalling contact of the knives with the stone (20) and to a rotation speed sensor (32) on the cutterhead (12). |