Abstract: In order to continuously change the transmission ratio between power-assisted steering mode and emergency steering mode and to maximize the flow of hydraulic oil in the power-assisted steering mode when the steering wheel is rapidly turned, a steering assembly is proposed which uses a common line which bypasses the metering pump, as a supply line for flow amplification during power-assisted operation and as a return line for changing the transmission ratio during emergency operation. This common line is connected to selected supply lines by way of throttles and with corresponding cylinder lines or with all cylinder lines by way of throttles. Steering devices of this type are employed in mobile equipment, in particular in slowly moving vehicles.

Abstract: Conventional steering systems of this type have the disadvantage that the dynamic load signal flow is lossy which has a negative effect on the energy efficiency. Another disadvantage arises in steering systems with a closed-center design. When the steering cylinder is pulled by an external force, the steering cylinder moves in advance of the apportioned steering flow. In the present novel steering system, the adjusting angles of the primary adjustable throttles (12, 13, 14, 15, 16, 17) are matched in a novel way, so that in a steering range where the steering rotational speed is limited, the load signal flow is used for actuating the steering system. In this phase, the steering system then operates according to the open-center principle.

Abstract: A hydraulic steering apparatus comprises a throttle (10) with a bypass line, eliminating the function of the throttle (10) in the direction of the steering cylinder (2). The throttle (10) is disposed between the control valve (3) of the steering apparatus (1) and the cylinder volume of the steering cylinder (2) on the piston rod side. The throttle (10) is used in connection with hydraulic steering apparatus for slow-moving vehicles.