Suspension system

Abstract

A harvesting machine with a main frame, a harvesting header having a first end and a second end and a suspension system operatively attached to the main frame for supporting the harvesting header from above, the harvesting header having a lowered position and a raised position. A suspension frame has a rocker arm operatively pivotally attached thereto along a first substantially horizontal axis, the rocker arm having an upper position and a lowermost position. A first link is operatively pivotally attached to the suspension frame along a second substantially horizontal axis and is operatively pivotally attached to the harvesting header at the other end thereof. A second link is operatively pivotally attached to the main frame along a third substantially horizontal axis and is operatively pivotally attached to the harvesting header at a fourth substantially horizontal axis, the second link being disposed substantially always parallel to the first link. A suspension lift bar is operatively pivotally attached to the rocker arm and is operatively pivotally attached to the harvesting header, the suspension lift bar (330) being disposed not parallel with respect to the first link. A biasing spring member is operatively attached to the suspension frame and is operatively attached at the other end thereof to the rocker arm for exerting a lift force on the rocker arm toward the upper position thereof. A force adjusting device on the biasing member is provided for adjusting the lift force on the harvesting header to counteract the weight of the harvesting header such that the effective ground weight of the harvesting header, less than the weight of the header, is required to lift the header upwardly and to permit the ground weight to be maintained substantially constant as the harvesting header moves between the lowered and the raised position thereof.

Dependencies are inferred from the claim text.