Crop harvesting machine base unit lift mechanism providing auxiliary height boost to crop gathering attachment

摘要

A crop harvesting machine has a crop gathering attachment lift mechanism which includes a pair of lift assemblies and a pair of actuators. Each lift assembly includes a lift arm and a boost arm. The lift arm is pivotally mounted to the base unit and pivotally connectable to the attachment. Pivoting of the lift arm causes raising of the attachment from its lowered position to a partially raised position being located at a height between its fully raised position and its lowered position. The boost arm is pivotally connected to the lift arm and has a roller rotatably mounted thereon for making rolling contact engagement with an arcuate cam structure on the attachment. The boost arm also is pivotally connected to the actuator. The actuator can be operated to initially cause the aforementioned pivoting of the lift arm to raise the attachment from its lowered to partially raised position and to thereafter cause pivoting of the boost arm relative to the lift arm to pivot the attachment relative to the lift arm and thereby raise the attachment from its partially raised to fully raised position. The use of the boost arm gives an auxiliary boost in the height to which the attachment can be lifted above the height which can be attained by the use of the lift arm alone.