Patent ID: 9198349
Filing Date: 2015-12-01
Classification: A01D,Y10T

Abstract:
1. A ground force control circuit ( 162 ) in combination with an articulated harvesting head ( 104 ) extending longitudinally in a direction perpendicular to a forward direction of travel (V) of the harvesting head ( 104 ), the articulated harvesting head ( 104 ) including a center section ( 146 ), a left section ( 144 ), and a right section ( 148 ), wherein a first hinge joint ( 150 ) defines a horizontal first pivot axis ( 154 ) extending in the direction of travel (V) and hingeably couples the left section ( 144 ) to the center section ( 146 ) for vertical movement relative to the center section ( 146 ), wherein a second hinge joint ( 152 ) defines a horizontal second pivot axis ( 156 ) extending in the direction of travel (V) and hingeably couples the right section ( 148 ) to the center section ( 146 ) for vertical movement relative to the center section ( 146 ), wherein a first single-acting hydraulic actuator ( 158 ) is pivotally coupled to the center section ( 146 ) and to the left section ( 144 ) to pivot the left section ( 144 ) vertically about the first pivot axis ( 154 ) with respect to the center section ( 146 ), and wherein a second single-acting hydraulic actuator ( 160 ) is pivotally coupled to the center section ( 146 ) and to the right section ( 148 ) to pivot the right section ( 148 ) vertically about the second pivot axis ( 156 ) with respect to the center section ( 146 ), and the ground force control circuit ( 162 ) comprising: an ECU ( a source of fluid pressure ( a sump ( a first solenoid-operated, proportional hydraulic control valve ( a pilot pressure line coupled between said at least one of said first and second single-acting hydraulic actuators (