Patent ID: 7475538

Claim:
A digital hydraulic system, comprising: fluid at high pressure; fluid at low pressure; a hydraulic actuator; a digital hydraulic transformer including: a fixed element having a first end and a second end; and a reciprocating element having a first end and a second end, said fixed element and said reciprocating element operating along a common axis, said first end of said fixed element and said first end of said reciprocating element, and said second end of said fixed element and said second end of said reciprocating element defining sets of cooperating pairs of pistons and cavities adapted to cooperate to thereby define two pluralities of variable volume working chambers, each of said pluralities of variable volume working chambers including a first working chamber, a second working chamber and a third working chamber, each of said working chambers having a surface area substantially normal to said common axis, said surface area of said first working chamber being related to said surface area of said second working chamber by a factor of approximately two, said surface area of said second working chamber being related to said surface area of said third working chamber by a factor of approximately two, said surface area of said first working chamber being related to said surface area of said third working chamber by a factor of approximately four; and a control system including: means to selectively fluidically connect each of said variable volume working chambers to one of said fluid at high pressure, said fluid at low pressure, and said hydraulic actuator; and means to ensure a continuous flow of hydraulic fluid in communication with said hydraulic actuator regardless of a direction of movement of said reciprocating element with respect to said fixed element.