Patent ID: 8052116

Claim:
A system, comprising: a hydraulic machine having a first port configured to be coupled to a high-pressure fluid supply and a second port configured to be coupled to a low-pressure fluid supply; a pilot-controlled fluid supply valve having: an output port in fluid communication with the first port of the hydraulic machine, an input port configured to be coupled to the high-pressure fluid supply, and a control port configured to receive an actuation signal, the fluid supply valve configured to allow passage of fluid from the output port to the input port, to block, while in a closed position, passage of fluid from the input port to the output port, and to permit, while in an open position, passage of fluid from the input port to the output port, the fluid supply valve further configured to bias toward the closed position while a first actuation signal is present at the control port, and bias toward the open position while a second actuation signal is present at the control port, the fluid supply valve being configured to block, after a signal at the control port changes from the first actuation signal to the second actuation signal, passage of fluid from the input port to the output port until a difference in pressure between a fluid pressure at the input port of the fluid supply valve and a fluid pressure at the output port of the fluid supply valve drops below a threshold difference greater than zero; and a pressurization valve having an input port configured to be coupled to the high-pressure fluid supply and an output port in fluid communication with the first port of the hydraulic machine, the pressurization valve being configured to block fluid passage between its input and output ports while in a first position, and to allow a restricted passage of fluid between its input and output ports while in a second position.