Implement stabilization method and apparatus

Claim 1

In a land vehicle having a vehicle mounted extensible tool controlled by a double acting pressure cylinder having tool extending and retracting chambers and a pair of vehiclestabilizing, ground-engaging arms, said arms each having a double acting fluid pressure cylinder including arm extending and retracting chambers and said arms extensible by said cylinders to support and stabilize said vehicle during extension and movement of said tool, and said cylinder chambers each selectively supplied with fluid pressure by a pump through a system of conduits, the improved control circuit for replenishing any loss of fluid pressure in either of said arm extending cylinder chambers, comprising: fluid supplementing circuits interconnecting each of said cylinder arm extending chambers with the supply conduit of said cylinder tool extending chamber, and a check valve in each of said fluid supplementing circuits permitting free flow of fluid from said tool supply conduit of said tool extending chamber to said cylinder arm extending chambers when the fluid pressure in said tool supply conduit exceeds the fluid pressure in either of said cylinder arm extending chambers, maintaining said arms in supporting and stabilizing position and said check valves preventing fluid flow from said cylinder arm extending chambers to said tool supply conduit of said cylinder tool extending chamber.