A control coupling of pressurized medium in a delimbing and cutting apparatus, provided for feeding members and for changing their feeding speed, said control coupling comprising at least: a first motor and a second motor that are coupled in parallel and drive a feeding member a third motor that is a multicapacity motor comprising a first half-motor and a second half-motor and that is coupled in series with the first motor and drives a feeding member; a fourth motor that is coupled in series with the second motor and drives a feeding member; first valve members that for the purpose of free rotation allow the feedback of the pressurized medium exiting the third motor to the first half-motor; and first control members that monitor the pressure of a first line and couple the first valve members to free rotation if said pressure is lower than the set value.