Patent ID: 7955058
Filing Date: 2011-06-07
Classification: F04B

Abstract:
1. A device consisting of a) three directly connected pistons, including an upper piston, middle piston, and lower piston, the diameters of said upper and said lower pistons are equal and said upper and lower piston diameters are less than the diameter of said middle piston, b) cylinder chambers for each of the said pistons, c) two input fluid control valves, that control the input fluid to either the said middle piston or the said upper and lower pistons, d) one of a pilot valve assembly and a set of four pilot valves that control input fluid to the said input fluid control valves, e) four check valves to control the direction of output fluid flow, f) an upper block that contains said upper piston, said upper piston cylinder chamber, one of said input fluid control valves, two of the said output fluid check valves, either the said upper half of the said pilot valve assembly or two of said pilot valves, and a set of fluid channels that interconnect: g) a lower block that contains said lower piston, said lower piston cylinder chamber, one of said input fluid control valves, the two output fluid check valves, either the said lower half of the pilot valve assembly or two of the said pilot valves, and a set of fluid channels that interconnect: