Vehicle steering apparatus
First Claim
1. A vehicle steering apparatus for a vehicle having a steering input control member rotatable about a central axis and a mechanism drivingly connected to left and right ground-engaging members, comprising:
- pump and motor means for controllably applying torque to the mechanism for steering the vehicle and including a steering pump and a displacement control for the steering pump;
control valve means for controllably delivering fluid under pressure to the displacement control, the control valve means including a right turn control valve and a left turn control valve in juxtaposed relation; and
steering means for converting the rotational movement of the input control member away from a centered position to linear actuation of a selected one of the control valves, the steering means including a first actuator mounted for rotation about the central axis and operatively connected to the right turn control valve and a second actuator mounted for rotation about the central axis and operatively connected to the left turn control valve.
1 Assignment
0 Petitions
Accused Products
Abstract
An improved mechanical-over-hydraulic steering apparatus capable of providing automotive-type steering includes a steering wheel driven input control member, right and left turn control valves, and first and second actuators mounted for rotation along an axis common with the input control member. Each of the actuators has a cam operatively associated with a cam-following roller assembly that operates the respective control valve. The vehicle has a cross drive mechanism, and the steering apparatus includes an over-center variable displacement steering pump and associated displacement control controllably operated by first and second pilot lines connected to the right and left turn control valves. The steering pump controllably and bidirectionally communicates fluid to a steering motor for the steering input to the cross drive mechanism.
56 Citations
42 Claims
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1. A vehicle steering apparatus for a vehicle having a steering input control member rotatable about a central axis and a mechanism drivingly connected to left and right ground-engaging members, comprising:
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pump and motor means for controllably applying torque to the mechanism for steering the vehicle and including a steering pump and a displacement control for the steering pump; control valve means for controllably delivering fluid under pressure to the displacement control, the control valve means including a right turn control valve and a left turn control valve in juxtaposed relation; and steering means for converting the rotational movement of the input control member away from a centered position to linear actuation of a selected one of the control valves, the steering means including a first actuator mounted for rotation about the central axis and operatively connected to the right turn control valve and a second actuator mounted for rotation about the central axis and operatively connected to the left turn control valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A vehicle steering apparatus for a vehicle having a steering input control member rotatable about a central axis and a mechanism drivingly connected to left and right ground-engaging members, comprising:
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pump and motor means for controllably applying torque to the mechanism for steering the vehicle and including a steering pump and a displacement control for the steering pump; control valve means for controllably delivering fluid under pressure to the displacement control, the control valve means including a right turn control valve and a left turn control valve in juxtaposed relation; and steering means for converting the rotational movement of the input control member away from a centered position to linear actuation of a selected one of the control valves, the steering means including an actuating member on the input control member, a first valve actuating cam at one side of the actuating member, a second valve actuating cam at the opposite side of the actuating member, and arm means associated with the respective actuating cams for being contacted by the actuating member for individual rotation of the valve actuating cams about the central axes. - View Dependent Claims (25, 26)
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27. A vehicle steering apparatus for operation of a steering pump having a displacement control associated therewith, comprising:
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an input control member rotatable about a central axis in either direction away from a centered position; a right turn control valve in fluid communication with the displacement control; a left turn control valve in fluid communication with the displacement control; a first cam mounted for rotation about the axis in a first direction away from a neutral position; a second cam mounted for rotation about the axis in a second direction away from a neutral position; first means for rotating the first cam through a first angular range and the second cam through a second angular range in response to rotation of the input control member; and second means for converting rotation of the first and second cams to linear actuation of the right turn and left turn control valves and operating the displacement control. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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38. A vehicle steering apparatus for converting the rotational movement of an input control member about an axis to hydraulic operation of a displacement control for a steering pump, comprising:
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a right turn control valve in fluid communication with the displacement control; a left turn control valve in fluid communication with the displacement control; a first actuator mounted for rotation in a first direction about the axis away from a neutral position and being operatively connected to the right turn control valve; a second actuator mounted for rotation in a second direction about the axis away from a neutral position and being operatively connected to the left turn control valve; first means for resiliently biasing the actuators towards their respective neutral positions; and second means for rotating the first actuator in the first direction through a first angular range and for rotating the second actuator in the second direction through a second angular range in response to rotation of the input control member in the first and second directions respectively against the reaction of the first means, the sum of the first and second angular ranges being greater than 360°
. - View Dependent Claims (39, 40, 41, 42)
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Specification