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AssigneeDanfoss A/S
InventorsPoul H. H. Pedersen, Thorkild Christensen, Johannes V. Baatrup, Svend E. Thomsen
Estimating the term…
A control valve is opened (moved from its neutral position) by rotation of a steering wheel to conduct fluid from a pump to a steering meter device that controls the amount of fluid fed to a steering motor arrangement. When the steering motor piston has been displaced by a distance corresponding to the angle of rotation of the steering wheel, the control valve is moved by the steering meter device from its opened condition to its neutral position. A pilot valve controlled actuating device is provided to short circuit the steering meter device to permit continued fluid flow from the pump to the steering motor device and provide a mechanical braking force to the meter device to block rotation thereof and thereby the movement of the control valve to its neutral position. The braking mechanism is resiliently urged to a non-braking position.
A vehicle steering arrangement comprising a hydraulic pump, a sump, a rotatable steering wheel, a steering motor arrangement, a rotatable steering metering device for controlling the amount of fluid fed to the steering motor arrangement, a control valve connected between the steering wheel and the metering device that is openable by rotation of the steering wheel and closeable by the subsequent rotation of the metering device after stoppage of the steering wheel rotation, fluid circuit means fluidly connecting the control valve between the pump and the steering motor arrangement via the steering metering device to effect conducting the fluid from the pump to the metering device and then from the metering device to the steering motor arrangement, the steering metering device including movable means for closing the control valve when the amount of hydraulic fluid corresponding to the angle of rotation of the steering wheel has flown through the circuit means to the steering motor arrangement by the way of flow from the control valve and back through the valve to the steering motor arrangement, and manually operable actuating means for preventing operation of the steering metering device from being effective to close the control valve, the actuating means including operable brake means to mechanically arrest the movable means and form an open fluid flow path short circuiting the steering metering device to allow further rotation of the steering wheel and thereby allow a further flow of hydraulic fluid to the steering motor arrangement to permit a further steering control capability thereof.
A vehicle steering arrangement of the type having a steering wheel and a fluid operated steering motor having operating ports, metering means, control valve means having a first part connected to and moveable by said steering wheel and a second cooperable part connected to and rotatable with said metering means, first fluid supply and return paths between said control valve means and said steering motor and second fluid supply and return paths between said control valve means and said metering means,
Dependencies are inferred from the claim text.