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.

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.

An improved cutter assembly for use with a header of an agricultural harvester is provided. The assembly includes a pair of oppositely directed knife blades or cutter bars and a center knife drive. A crank shaft drives both knife blades in linear reciprocating paths with no fore and aft movement. As a consequence, harmful fore and aft vibration is eliminated. The assembly is simple and durable in design, less susceptible to vibration-induced wear and tear, and comparatively simple to manufacture and repair.

An agricultural system includes an arm of a header. The arm is configured to rotate about a pivot joint. The agricultural system also includes a fluid-filled biasing member, an actuator, and a controller. The fluid-filled biasing member is configured to couple to the arm and to impart a torque onto the arm. The actuator is coupled to the fluid-filled biasing member and is configured to move the fluid-filled biasing member relative to the actuator to change the torque imparted by the fluid-filled biasing member onto the arm. The controller configured to receive an input indicative of a target flotation pressure of the arm output a signal to instruct the actuator to set a position of the fluid-filled biasing member relative to the actuator based at least in part on the target flotation pressure of the arm.

An agricultural system includes an arm of a header. The arm is configured to rotate about a pivot joint. The agricultural system also includes a fluid-filled biasing member, an actuator, and a controller. The fluid-filled biasing member is configured to couple to the arm and to impart a torque onto the arm. The actuator is coupled to the fluid-filled biasing member and is configured to move the fluid-filled biasing member relative to the actuator to change the torque imparted by the fluid-filled biasing member onto the arm. The controller configured to receive an input indicative of a target flotation pressure of the arm output a signal to instruct the actuator to set a position of the fluid-filled biasing member relative to the actuator based at least in part on the target flotation pressure of the arm.

A mowing sickle drive system comprises a knife bar supported by a frame and drive apparatus operable to drive the knife bar in a reciprocating linear motion at a variable drive frequency. A spring is coupled to the knife bar for applying a restoring force to the knife bar toward a neutral position when in motion. The spring has a variable modulus of elasticity that is controlled dependent upon the drive frequency.

A mowing sickle drive system comprises a knife bar supported by a frame and drive apparatus operable to drive the knife bar in a reciprocating linear motion at a variable drive frequency. A spring is coupled to the knife bar for applying a restoring force to the knife bar toward a neutral position when in motion. The spring has a variable modulus of elasticity that is controlled dependent upon the drive frequency.

A mowing sickle drive system comprises a knife bar supported by a frame and drive apparatus operable to drive the knife bar in a reciprocating linear motion at a variable drive frequency. A spring is coupled to the knife bar for applying a restoring force to the knife bar toward a neutral position when in motion. The spring has a variable modulus of elasticity that is controlled dependent upon the drive frequency.

A header for an agricultural harvester comprising a frame and an epicyclical drive supported by the frame. The epicyclical drive includes a first rotatable wheel having a first substantially vertical rotational axis and a first disk. The first disk includes a first eccentric axis rotatable about the first rotational axis. The epicyclical drive further includes a second rotatable wheel having a second substantially vertical rotational axis and a second disk. The second disk includes a second eccentric axis rotatable about the second rotational axis. The header further includes a first cutter bar directly connected to the first disk and a second cutter bar directly connected to the second disk. Operation of the epicyclical drive results in substantially linear oscillating motion of the cutter bars.

An improved cutter assembly for use with a header of an agricultural harvester is provided. The assembly includes a pair of oppositely directed knife blades or cutter bars and a center knife drive. A crank shaft drives both knife blades in linear reciprocating paths with no fore and aft movement. As a consequence, harmful fore and aft vibration is eliminated. The assembly is simple and durable in design, less susceptible to vibration-induced wear and tear, and comparatively simple to manufacture and repair.