Patent ID: 9494168
Filing Date: 2016-11-15
CPC Classification: F15B

Claim Text:
1. An energy efficient, fluid powered, single-acting, linear actuation system comprising: a hydraulic cylinder barrel having a cap end wall, a tubular outer wall extending from the cap end wall and circumscribing an axially-extending, longitudinal centerline, and concentric inner walls spaced radially inward of the outer wall and extending axially from the cap end wall; a piston for engaging a load force, said piston having a base wall, concentric walls spaced radially outward of one another and axially extending from the base wall, said piston is disposed within said hydraulic cylinder barrel and the concentric walls of said barrel and the concentric walls of said piston cooperate to define a plurality of concentric extension chambers; a low pressure valve fluidly coupling each of the extension chambers to a common low pressure reservoir; a high pressure valve fluidly coupling each of the extension chambers to a common high pressure accumulator; a working fluid disposed within at least the chambers, valves, low pressure reservoir and high pressure accumulator; wherein, when the system is configured in an energy consuming mode and the load force is in an opposite direction as an extending piston force direction, the high pressure valves fluidly coupling the active extension chambers to the high pressure accumulator are configured in an open position, and the low pressure valves fluidly coupling the passive extension chambers to the low pressure reservoir are configured in an open position and all other valves are configured in a closed position; and when the system is configured in an energy recovery mode and the load force is in the same direction as a retracting piston force, the high pressure valves fluidly coupling the active extension chambers to the high pressure accumulator are configured in an open position and the low pressure valves fluidly coupling the passive extension chambers to the low pressure reservoir are configured in an open position and all other valves are configured in a closed position.