Patent ID: 7810304

Claim:
An epicyclic drive of a sickle, the epicycylic drive disposed within a housing, the epicyclic drive comprising: an input element supported for rotation about a central rotational axis therethrough; a pinion shaft extending through the housing, the pinion shaft having a longitudinal axis concentric with an eccentric axis, the eccentric axis offset and parallel to the central rotational axis; a pinion gear supported on the pinion shaft such that when the input element is rotated about the central rotational axis, the pinion gear will cause the pinion shaft to rotate therewith about the eccentric axis; a fixed ring gear concentric with the central rotational axis and enmeshed with the pinion gear such that rotation of the input element about the central rotational axis will cause the pinion gear to rotate around the ring gear about the central rotational axis and simultaneously rotate about the eccentric axis, wherein rotation of the pinion gear causes the pinion shaft to orbit in a first direction around the central rotational axis while simultaneously rotating about the eccentric axis in a second and opposite direction; an eccentric element mounted to the pinion shaft so that a central axis of the eccentric element is eccentric to the eccentric axis, wherein the eccentric element orbits about the ring gear and the central rotational axis when the input element is rotated, while simultaneously rotating about the eccentric axis in the second direction; a knife head bearing supported on and extending around the eccentric element; and a knife head assembly connected to a sickle knife assembly, the knife head assembly including an element supported on and extending around the knife head bearing and configured so as to transfer sidewardly directed components of rotations of the eccentric element into sideward reciprocating movements of the sickle knife assembly.