Patent ID: 6374940
Filing Date: 2002-04-23
Classification: B62D

Abstract:
A steering device for self-propelled working machines having steerable wheels including: at least one steering cylinder associated with at least one pair of wheels, at least one valve unit for controlling the flow of a fluid to the at least one steering cylinder, a supply unit comprising a control valve connected to an output of a hydraulic pump operatively connected to at least one flow control valve of a first steering control unit and to a hydraulic device of a second steering control unit that is operatively connected to the at least one valve unit to provide a flow of the fluid thereto; the first steering control unit and the second steering control unit the at least one valve unit each include a respective switching unit incorporating at least one on-off valve of each steering control unit being automatically switchable in the event of a fault in a manner such that the at least one steering cylinder may be controlled by the second steering control unit providing all wheel steering by by-passing the first steering control unit and the respective switching unit.