Hydraulic steering system
AssigneeNew Holland North America, Inc.
InventorsMassimo Biggi, Angelo Gregorio, Enrico Sedoni
Life of this patent
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Abstract
A hydraulic steering system for a tractor is provided which can be operated in a conventional steering mode or in a fast steering mode. In conventional steering mode, a conventional steering wheel and steering motor direct pressurized oil to the steerable wheels for selecting the turning direction, the turning angle, and the speed with which the turning angle is achieved. In fast steering mode, a fast-turning valve is controlled by the operator to direct oil directly to the steerable wheels, thereby by-passing the steering motor. The conventional steering wheel and steering motor continue however to control the steering operation.
Claims20
In a hydraulic steering system having a first pump mechanically pumping fluid from a tank;
- and a hydraulic circuit in flow communication with said first pump, said hydraulic circuit including a switching mechanism for selecting pressurized fluid flows for selective supply to steering actuator, a second pump regulated by a steering input device operated by the operator to select a turning direction, a turning angle, and a speed with which said turning angle is reached;
- and a fast-turning mechanism selectively activated by the operator for initiating a fast steering mode of operation, the improvement comprising:
- said fast turning mechanism being operatively associated with said steering input device such that said steering input device is operable to select the turning direction, the turning angle, and the steering speed with which said turning angle is reached when in said fast steering mode of operation.
In a hydraulic steering system having a first pump mechanically pumping fluid from a tank;
- and a hydraulic circuit in flow communication with said first pump, said hydraulic circuit including a switching mechanism for selecting pressurized fluid flows for selective supply to steering actuator, a second pump regulated by a steering input device operated by the operator to select a turning direction, a turning angle, and a speed with which said turning angle is reached;
- and a fast-turning mechanism selectively activated by the operator for initiating a fast steering mode of operation, the improvement comprising:
- said second pump and said steering input device being operable upon activation of said fast turning mechanism to select the turning direction, the turning angle, and the steering speed with which said turning angle is reached, said steering speed being directly proportional to an intensity of operator force on said steering input device.
Dependencies are inferred from the claim text.