US Patent 10151080 Valve assembly for work attachment

A hydraulic control for an attachment on a work vehicle. The attachment is mounted on the chassis of the work vehicle and movable between a first position and a second position. A hydraulic cylinder is operable to power movement of the attachment. A fluid circuit communicates with the hydraulic cylinder and is configured to carry hydraulic fluid. A fluid reservoir is in communication with the fluid circuit. Accumulators that are in communication with the fluid circuit automatically store and release hydraulic fluid in response to movement of the attachment. A valve assembly controls fluid communication between the fluid reservoir and the fluid circuit in response to movement of the attachment to its second position.