Patent ID: 7487707

Claim:
A hydraulic circuit for controlling flow of fluid between a hydraulic actuator, that has a first port and a second port, and each of a supply conduit and a tank return conduit, said hydraulic circuit comprising: a spool valve having an inlet connected to the supply conduit, an outlet connected to the tank return conduit, a first workport and a second workport, wherein the spool valve selectively directs fluid from the inlet to one of the first and second workports and selectively directs fluid from another of the first and second workports to the outlet; a workport blocking valve connecting connected between the first workport to the first port of the hydraulic actuator; and a regeneration shunt valve connected to the hydraulic actuator and through which fluid flows between the first port and the second port, wherein the regeneration shunt valve has a first position in which fluid flow between the first port and the second port in both directions is blocked and has a second position that conveys fluid between the first port and the second port regardless of the state of the workport blocking valve.