Electro-hydraulic actuator with a pilot-actuated float mode

A hydraulic system comprising:

• a hydraulic cylinder actuator having a cylinder and a piston axially movable in the cylinder, wherein the piston has a piston head that divides an internal space of the cylinder into a first chamber and a second chamber;
• a fluid reservoir;
• a pilot pressure source that generates a pilot fluid signal;
• and
• a valve assembly that controls fluid flow to and from the hydraulic cylinder actuator, wherein the valve assembly has (i) a first workport fluidly coupled to the first chamber, (ii) a second workport fluidly coupled to the second chamber, (iii) a reservoir port fluidly coupled to the fluid reservoir, (iv) a pilot port fluidly coupled to the pilot pressure source to receive the pilot fluid signal, and (v) a first spool and a second spool, wherein the pilot fluid signal actuates the first spool and the second spool to fluidly couple the first workport and the second workport to the reservoir port, thereby operating the piston in a float mode.

A method comprising:

• providing a pilot fluid signal to a pilot port of a valve assembly comprising a first workport fluidly coupled to a first chamber of a hydraulic cylinder actuator, a second workport fluidly coupled to a second chamber of the hydraulic cylinder actuator, and a reservoir port that is fluidly coupled to a fluid reservoir;
• responsive to the pilot fluid signal, causing a first spool of the valve assembly to move in a first direction, thereby opening a first check valve and fluidly coupling the first workport of the valve assembly to the reservoir port;
• and
• responsive to the pilot fluid signal, causing a second spool of the valve assembly to move in a second direction, opposite the first direction, thereby opening a second check valve and fluidly coupling the second workport of the valve assembly to the reservoir port.