MULTI-SECTION HEADER WITH FLEXIBLE CROP CUTTING KNIFE

摘要

A crop harvesting header for mounting on a propulsion vehicle such as a swather tractor or combine harvester includes a main frame structure supporting a crop receiving table with a cutter bar across a front of the table and side drape rs on the table for moving the cut crop toward a discharge location of the header. The frame is divided into a central frame portion and two separate wing frame portions each arranged for pivotal movement relative to the central portion about a pivot axis extending in a plane parallel to the forward direction and intersecting the cutter bar so that, as the wing frame portions pivot, the cutter bar flexes in the area adjacent the respective pivot axis over a small angle of the order of 4 degrees to maintain the cutter bar following the ground. The central frame portion is mounted on two spring arms for upward and twisting floating movement such that the total downward force on the ground, from that part of the weight of all of the portions of the header which is unsupported, can be varied by moving the support to change t he total pressure of the header on the ground. The wing frame portions are connected to the central frame portion by interconnecting linkages which transfer weight from the win g frame portions to the springs of the central portion each including arespective balance bea m arranged to balance the lifting force from the spring with the downward forces from the center portion and wing frame portion such that the downward force on a skid plate of each portion on the ground varies automatically as the total downward force is varied. A bottom stop is arranged with a balance system which holds the cutter bar straight when the header is raised.