Patent ID: 7578222

Claim:
A rotary cutter, comprising: a first knife located on a knife shaft having a longitudinal axis; a second knife spaced from the first knife by an adjustable cutting gap; a control unit including a drive for turning one of the first knife or the second knife, with the other one of the first knife or the second knife separated from the one knife and remaining rotationally stationary; and an adjusting mechanism for moving at least one of the first knife or the second knife in the direction of the longitudinal axis to adjust the cutting gap, the adjusting mechanism comprising: a first signal transmitter for detecting a zero position of the first and second knives by detecting an initial rotation from a stationary position of the other one of the first and second knife imparted by frictional contact of the first knife with the second knife; a second signal transmitter for detecting a cutting position of the first and second knives; and an adjustment drive coupled to the first and second signal transmitters for movement of at least one of the first knife or second knife from the zero position to the cutting position.