Patent ID: 7478683
Filing Date: 2009-01-20
Classification: A01B

Abstract:
1. A hydraulic lift system for a multi-sectioned agricultural implement having a main frame and outer wing frames movably connected to the main frame, the lift system comprising: first and second lift wheel arms connected to the main frame: first and second lift cylinders havinci rod and base ends, the first and second lift cylinders connected to the first lift wheel arm and constrained for movement together in unison with the first lift wheel arm independently of rockshaft structure: third and fourth lift cylinders having rod and base ends, the third and fourth cylinders connected to the second lift wheel arm and constrained for movement together in unison: wherein the first and second cylinders are connected in parallel and are constrained for extension and retraction together with movement of the first lift wheel arm, and the base ends of the first and second cylinders are connected to the base end of the fourth cylinder and to a source of hydraulic fluid under pressure for extending and retracting the first, second and fourth cylinders: a conduit connecting the rod end of the first cylinder with the base end of the third cylinder to thereby synchronize the movement of the first and second cylinders with the third and fourth cylinders independently of any mechanical linkage between the first and second lift wheel arms: fifth and sixth wing lift cylinders connected to outer wing frames, the fifth cylinder connected for operation in series with one of the first and second cylinders and the sixth cylinder connected for operation in series with one of the third and fourth cylinders so that the main frame and the wing frames move vertically generally in unison: wherein the fifth and sixth wing lift cylinders are connected to wing lift wheel assemblies, and further including a wing fold cylinder circuit connected to the outer wings for folding the wings between transport and field-working positions, and connecting valve structure selectively interconnecting the wing fold cylinder circuit with the lift cylinders for operating the wing lift cylinders to prevent interference between the wing lift wheel assemblies and portions of the implement during the folding of the wings: wherein the connecting valve structure facilitates implement lowering when the wings are folded in the transport position.