Patent ID: 7918076
Filing Date: 2011-04-05
Classification: A01D

Abstract:
1. A crop harvesting header comprising: a main frame structure extending across a width of the header for movement in a forward direction generally at right angles to the width across ground including a crop to be harvested; a mounting assembly for carrying the main frame structure on a propulsion vehicle; a crop receiving table carried on the main frame structure across the width of the header; a cutter bar across a front of the table arranged to move over the ground in a cutting action and carrying a cutter knife operable for cutting the crop as the header is moved forwardly across the ground for depositing the crop onto the table; a skid element extending across the width of the header for engaging the ground so as to receive lifting forces from the ground at whatever points of the skid element contact the ground tending to lift the cutter bar; a crop transport system on the table for moving the cut crop toward a discharge location of the header; the main frame structure including a center frame portion, a first wing frame portion and a second wing frame portion; the first wing frame portion being connected to the center frame portion by a first pivot coupling arranged for pivotal movement of the first wing frame portion relative to the center frame portion about a first pivot axis extending in a plane parallel to the forward direction; the first pivot coupling thus acting to support weight from the first wing frame portion at the pivot coupling while weight from the first wing frame portion outboard of the first pivot coupling tends to rotate the first wing frame portion about the first pivot coupling in a downward direction; the second wing frame portion being connected to the center frame portion by a second pivot coupling arranged for pivotal movement of the second wing frame portion relative to the center frame portion about a second pivot axis extending in a plane parallel to the forward direction; the second pivot coupling thus acting to support weight from the second wing frame portion at the second pivot coupling while weight from the second wing frame portion outboard of the second pivot coupling tends to rotate the second wing frame portion about the second pivot coupling in a downward direction; the mounting assembly including a first spring biased lifting member for applying a first spring lifting force and a second spring biased lifting member for applying a second spring lifting force arranged at transversely spaced positions on the center frame portion of the main frame structure; a first linkage for applying a first wing lifting force to the first wing frame portion in a direction to support the first wing frame portion against said rotating movement about the first pivot coupling; a second linkage for applying a second wing lifting force to the second wing frame portion in a direction to support the second wing frame portion against said rotating movement about the second pivot coupling; a first balance system including a first balance beam pivotally connected at a first pivot connection to the center frame portion of the main frame structure for applying a first center frame portion lifting force to the center frame portion; the first balance beam being connected to the first linkage so as to apply thereto the first wing lifting force; the first balance beam being arranged to receive the first spring lifting force from the first spring biased lifting member at a first lift position therealong so as to balance the first spring lifting force between the first center frame portion lifting force and the first wing lifting force; and a second balance system including a second balance beam pivotally connected at a second pivot connection to the center frame portion of the main frame structure for applying a second center frame portion lifting force to the center frame portion; the second balance beam being connected to the second linkage so as to apply thereto the second wing lifting force; the second balance beam being arranged to receive the second spring lifting force from the second spring biased lifting member at a second lift position therealong so as to balance the second spring lifting force between the second center frame portion lifting force and the second wing lifting force; wherein the mounting assembly is connected to the main frame structure so as to allow adjustment movement of the main frame structure relative to the mounting assembly; wherein there is provided a first element arranged to be responsive to the adjustment movement and arranged in response to the adjustment movement to operate on the first balance beam to change the balance of forces between the first wing lifting force and the first center frame portion lifting force in proportion to the amount of adjustment movement; and wherein there is provided a second element responsive to the adjustment movement to operate on the second balance beam to change the balance of forces between the second wing lifting force and the second center frame portion lifting force in proportion to the amount of adjustment movement.