摘要 |
<p>A load responsive system having at least one direction and flow control valve, the flow control of which is accomplished in response to a control signal above a certain predetermined pressure level and a fixed displacement pump, provided with a bypass type output flow control, operable to maintain a constant pressure differential between pump discharge pressure and load pressure of the load controlled by the direction and flow control valve. The output flow control is provided with an unloading control, which maintains the discharge pressure of the pump at any preselected minimum pressure level once the control signal transmitted to the direction and flow control valve drops below a certain minimum predetermined pressure level signifying that the system is in standby condition.</p> |