A drive arrangement for the reciprocating drive of a cutter bar comprises an input element which can be set into a continuous pivoting movement by a drive device, and an output element which is coupled to the cutter bar and is coupled to the input element by a coupling rod. The output element is pivotably connected to a first end of a first lever and of a second lever, which levers, for their part, are pivotably mounted. The levers and the output element are dimensioned in such a manner that the output element essentially only carries out a lateral movement.

A header of an agricultural harvester or plant cutting machine is provided that includes a shaft sealing assembly for a center knife drive assembly having an output shaft, a cover, and a pressurized air source. The shaft sealing assembly is fastened to the cover, circumscribes the output shaft and conveys pressurized air for cleaning.

A header of an agricultural harvester or plant cutting machine is provided that includes a shaft sealing assembly for a center knife drive assembly having an output shaft, a cover, and a pressurized air source. The shaft sealing assembly is fastened to the cover, circumscribes the output shaft and conveys pressurized air for cleaning.

A header of an agricultural harvester or plant cutting machine is provided that includes a shaft sealing assembly for a center knife drive assembly having an output shaft, a cover, and a pressurized air source. The shaft sealing assembly is fastened to the cover, circumscribes the output shaft and conveys pressurized air for cleaning.

A header of an agricultural harvester or plant cutting machine is provided that includes a shaft sealing assembly for a center knife drive assembly having an output shaft, a cover, and a pressurized air source. The shaft sealing assembly is fastened to the cover, circumscribes the output shaft and conveys pressurized air for cleaning.

A reciprocating power tool comprising a first blade and a second blade, wherein the first blade is driven by a first shaft assembly, wherein the second blade is driven by a second shaft assembly, wherein the first and second blade assemblies are reciprocally driven by a cam shaft, wherein the first shaft assembly defines a first moment of inertia, wherein the second shaft assembly defines a second moment of inertia, and wherein the first and second moments of inertia are within 5% of one another.

A sickle drive incorporated into a generally flat package or enclosure or floor. The drive includes an epicyclic mechanism, including a rotatable input element in an upper region of a cavity of the enclosure, and an eccentric element below the input element rotatable eccentrically thereby. A drive arm is connected to the eccentric element for rotation about, and eccentric rotation with, the eccentric element, and extends to a pivot element which can be the only component extending upwardly from the enclosure or floor, such that the shaft will be pivoted by the eccentric movement of the drive arm. A knife arm connects to the pivot element and a sickle knife assembly which will be reciprocated by the pivoting action. A second epicyclic arrangement can be employed such that opposite forces generated by operation of the drive will be largely canceled.

A sickle drive incorporated into a generally flat package or enclosure or floor. The drive includes an epicyclic mechanism, including a rotatable input element in an upper region of a cavity of the enclosure, and an eccentric element below the input element rotatable eccentrically thereby. A drive arm is connected to the eccentric element for rotation about, and eccentric rotation with, the eccentric element, and extends to a pivot element which can be the only component extending upwardly from the enclosure or floor, such that the shaft will be pivoted by the eccentric movement of the drive arm. A knife arm connects to the pivot element and a sickle knife assembly which will be reciprocated by the pivoting action. A second epicyclic arrangement can be employed such that opposite forces generated by operation of the drive will be largely canceled.

A sickle drive incorporated into a generally flat package or enclosure or floor. The drive includes an epicyclic mechanism, including a rotatable input element in an upper region of a cavity of the enclosure, and an eccentric element below the input element rotatable eccentrically thereby. A drive arm is connected to the eccentric element for rotation about, and eccentric rotation with, the eccentric element, and extends to a pivot element which can be the only component extending upwardly from the enclosure or floor, such that the shaft will be pivoted by the eccentric movement of the drive arm. A knife arm connects to the pivot element and a sickle knife assembly which will be reciprocated by the pivoting action. A second epicyclic arrangement can be employed such that opposite forces generated by operation of the drive will be largely canceled.

A knife drive assembly for use in a harvesting header may be mounted near the center line of the cutter bar of the header. Mechanical power from the power unit behind the header (typically the combine power output shaft) may be translated for application to two knife assembly sections in the cutter bar at the front of the cutter table. Movement of the two knife assembly sections with this apparatus can be fully synchronized and 180 degrees out of phase, to maximize cutting effectiveness and minimize vibration of the header. The unitary drive assembly may allow for rapid repair and manufacture, and the size and weight of the knife drive assembly may represent a significant weight and balance advantage over the prior art.